QEMU QMP Reference Manual

Introduction

This document describes all commands currently supported by QMP.

Most of the time their usage is exactly the same as in the user Monitor, this means that any other document which also describe commands (the manpage, QEMU’s manual, etc) can and should be consulted.

QMP has two types of commands: regular and query commands. Regular commands usually change the Virtual Machine’s state someway, while query commands just return information. The sections below are divided accordingly.

It’s important to observe that all communication examples are formatted in a reader-friendly way, so that they’re easier to understand. However, in real protocol usage, they’re emitted as a single line.

Also, the following notation is used to denote data flow:

Example:

-> data issued by the Client
<- Server data response

Please refer to the QEMU Machine Protocol Specification for detailed information on the Server command and response formats.

QMP errors

QapiErrorClass (Enum)

QEMU error classes

Values

GenericError

this is used for errors that don’t require a specific error class. This should be the default case for most errors

CommandNotFound

the requested command has not been found

DeviceNotActive

a device has failed to be become active

DeviceNotFound

the requested device has not been found

KVMMissingCap

the requested operation can’t be fulfilled because a required KVM capability is missing

Since

1.2

Common data types

IoOperationType (Enum)

An enumeration of the I/O operation types

Values

read

read operation

write

write operation

Since

2.1

OnOffAuto (Enum)

An enumeration of three options: on, off, and auto

Values

auto

QEMU selects the value between on and off

on

Enabled

off

Disabled

Since

2.2

OnOffSplit (Enum)

An enumeration of three values: on, off, and split

Values

on

Enabled

off

Disabled

split

Mixed

Since

2.6

StrOrNull (Alternate)

This is a string value or the explicit lack of a string (null pointer in C). Intended for cases when ‘optional absent’ already has a different meaning.

Members

s: string

the string value

n: null

no string value

Since

2.10

OffAutoPCIBAR (Enum)

An enumeration of options for specifying a PCI BAR

Values

off

The specified feature is disabled

auto

The PCI BAR for the feature is automatically selected

bar0

PCI BAR0 is used for the feature

bar1

PCI BAR1 is used for the feature

bar2

PCI BAR2 is used for the feature

bar3

PCI BAR3 is used for the feature

bar4

PCI BAR4 is used for the feature

bar5

PCI BAR5 is used for the feature

Since

2.12

PCIELinkSpeed (Enum)

An enumeration of PCIe link speeds in units of GT/s

Values

2_5

2.5GT/s

5

5.0GT/s

8

8.0GT/s

16

16.0GT/s

32

32.0GT/s (since 9.0)

64

64.0GT/s (since 9.0)

Since

4.0

PCIELinkWidth (Enum)

An enumeration of PCIe link width

Values

1

x1

2

x2

4

x4

8

x8

12

x12

16

x16

32

x32

Since

4.0

HostMemPolicy (Enum)

Host memory policy types

Values

default

restore default policy, remove any nondefault policy

preferred

set the preferred host nodes for allocation

bind

a strict policy that restricts memory allocation to the host nodes specified

interleave

memory allocations are interleaved across the set of host nodes specified

Since

2.1

NetFilterDirection (Enum)

Indicates whether a netfilter is attached to a netdev’s transmit queue or receive queue or both.

Values

all

the filter is attached both to the receive and the transmit queue of the netdev (default).

rx

the filter is attached to the receive queue of the netdev, where it will receive packets sent to the netdev.

tx

the filter is attached to the transmit queue of the netdev, where it will receive packets sent by the netdev.

Since

2.5

GrabToggleKeys (Enum)

Key combinations to toggle input-linux between host and guest.

Values

ctrl-ctrl

left and right control key

alt-alt

left and right alt key

shift-shift

left and right shift key

meta-meta

left and right meta key

scrolllock

scroll lock key

ctrl-scrolllock

either control key and scroll lock key

Since

4.0

HumanReadableText (Object)

Members

human-readable-text: string

Formatted output intended for humans.

Since

6.2

Socket data types

NetworkAddressFamily (Enum)

The network address family

Values

ipv4

IPV4 family

ipv6

IPV6 family

unix

unix socket

vsock

vsock family (since 2.8)

unknown

otherwise

Since

2.1

InetSocketAddressBase (Object)

Members

host: string

host part of the address

port: string

port part of the address

InetSocketAddress (Object)

Captures a socket address or address range in the Internet namespace.

Members

numeric: boolean (optional)

true if the host/port are guaranteed to be numeric, false if name resolution should be attempted. Defaults to false. (Since 2.9)

to: int (optional)

If present, this is range of possible addresses, with port between port and to.

ipv4: boolean (optional)

whether to accept IPv4 addresses, default try both IPv4 and IPv6

ipv6: boolean (optional)

whether to accept IPv6 addresses, default try both IPv4 and IPv6

keep-alive: boolean (optional)

enable keep-alive when connecting to this socket. Not supported for passive sockets. (Since 4.2)

mptcp: boolean (optional) (If: HAVE_IPPROTO_MPTCP)

enable multi-path TCP. (Since 6.1)

The members of InetSocketAddressBase

Since

1.3

UnixSocketAddress (Object)

Captures a socket address in the local (“Unix socket”) namespace.

Members

path: string

filesystem path to use

abstract: boolean (optional) (If: CONFIG_LINUX)

if true, this is a Linux abstract socket address. path will be prefixed by a null byte, and optionally padded with null bytes. Defaults to false. (Since 5.1)

tight: boolean (optional) (If: CONFIG_LINUX)

if false, pad an abstract socket address with enough null bytes to make it fill struct sockaddr_un member sun_path. Defaults to true. (Since 5.1)

Since

1.3

VsockSocketAddress (Object)

Captures a socket address in the vsock namespace.

Members

cid: string

unique host identifier

port: string

port

Note

String types are used to allow for possible future hostname or service resolution support.

Since

2.8

FdSocketAddress (Object)

A file descriptor name or number.

Members

str: string

decimal is for file descriptor number, otherwise it’s a file descriptor name. Named file descriptors are permitted in monitor commands, in combination with the ‘getfd’ command. Decimal file descriptors are permitted at startup or other contexts where no monitor context is active.

Since

1.2

InetSocketAddressWrapper (Object)

Members

data: InetSocketAddress

internet domain socket address

Since

1.3

UnixSocketAddressWrapper (Object)

Members

data: UnixSocketAddress

UNIX domain socket address

Since

1.3

VsockSocketAddressWrapper (Object)

Members

data: VsockSocketAddress

VSOCK domain socket address

Since

2.8

FdSocketAddressWrapper (Object)

Members

data: FdSocketAddress

file descriptor name or number

Since

1.3

SocketAddressLegacy (Object)

Captures the address of a socket, which could also be a named file descriptor

Members

type: SocketAddressType

Transport type

The members of InetSocketAddressWrapper when type is "inet"

The members of UnixSocketAddressWrapper when type is "unix"

The members of VsockSocketAddressWrapper when type is "vsock"

The members of FdSocketAddressWrapper when type is "fd"

Since

1.3

SocketAddressType (Enum)

Available SocketAddress types

Values

inet

Internet address

unix

Unix domain socket

vsock

VMCI address

fd

Socket file descriptor

Since

2.9

SocketAddress (Object)

Captures the address of a socket, which could also be a socket file descriptor

Members

type: SocketAddressType

Transport type

The members of InetSocketAddress when type is "inet"

The members of UnixSocketAddress when type is "unix"

The members of VsockSocketAddress when type is "vsock"

The members of FdSocketAddress when type is "fd"

Since

2.9

VM run state

RunState (Enum)

An enumeration of VM run states.

Values

debug

QEMU is running on a debugger

finish-migrate

guest is paused to finish the migration process

inmigrate

guest is paused waiting for an incoming migration. Note that this state does not tell whether the machine will start at the end of the migration. This depends on the command-line -S option and any invocation of ‘stop’ or ‘cont’ that has happened since QEMU was started.

internal-error

An internal error that prevents further guest execution has occurred

io-error

the last IOP has failed and the device is configured to pause on I/O errors

paused

guest has been paused via the ‘stop’ command

postmigrate

guest is paused following a successful ‘migrate’

prelaunch

QEMU was started with -S and guest has not started

restore-vm

guest is paused to restore VM state

running

guest is actively running

save-vm

guest is paused to save the VM state

shutdown

guest is shut down (and -no-shutdown is in use)

suspended

guest is suspended (ACPI S3)

watchdog

the watchdog action is configured to pause and has been triggered

guest-panicked

guest has been panicked as a result of guest OS panic

colo

guest is paused to save/restore VM state under colo checkpoint, VM can not get into this state unless colo capability is enabled for migration. (since 2.8)

ShutdownCause (Enum)

An enumeration of reasons for a Shutdown.

Values

none

No shutdown request pending

host-error

An error prevents further use of guest

host-qmp-quit

Reaction to the QMP command ‘quit’

host-qmp-system-reset

Reaction to the QMP command ‘system_reset’

host-signal

Reaction to a signal, such as SIGINT

host-ui

Reaction to a UI event, like window close

guest-shutdown

Guest shutdown/suspend request, via ACPI or other hardware-specific means

guest-reset

Guest reset request, and command line turns that into a shutdown

guest-panic

Guest panicked, and command line turns that into a shutdown

subsystem-reset

Partial guest reset that does not trigger QMP events and ignores –no-reboot. This is useful for sanitizing hypercalls on s390 that are used during kexec/kdump/boot

snapshot-load

A snapshot is being loaded by the record & replay subsystem. This value is used only within QEMU. It doesn’t occur in QMP. (since 7.2)

StatusInfo (Object)

Information about VM run state

Members

running: boolean

true if all VCPUs are runnable, false if not runnable

status: RunState

the virtual machine RunState

Since

0.14

query-status (Command)

Query the run status of the VM

Returns

StatusInfo reflecting the VM

Since

0.14

Example:

-> { "execute": "query-status" }
<- { "return": { "running": true,
                 "status": "running" } }

SHUTDOWN (Event)

Emitted when the virtual machine has shut down, indicating that qemu is about to exit.

Arguments

guest: boolean

If true, the shutdown was triggered by a guest request (such as a guest-initiated ACPI shutdown request or other hardware-specific action) rather than a host request (such as sending qemu a SIGINT). (since 2.10)

reason: ShutdownCause

The ShutdownCause which resulted in the SHUTDOWN. (since 4.0)

Note

If the command-line option -no-shutdown has been specified, qemu will not exit, and a STOP event will eventually follow the SHUTDOWN event.

Since

0.12

Example:

<- { "event": "SHUTDOWN",
     "data": { "guest": true, "reason": "guest-shutdown" },
     "timestamp": { "seconds": 1267040730, "microseconds": 682951 } }

POWERDOWN (Event)

Emitted when the virtual machine is powered down through the power control system, such as via ACPI.

Since

0.12

Example:

<- { "event": "POWERDOWN",
     "timestamp": { "seconds": 1267040730, "microseconds": 682951 } }

RESET (Event)

Emitted when the virtual machine is reset

Arguments

guest: boolean

If true, the reset was triggered by a guest request (such as a guest-initiated ACPI reboot request or other hardware-specific action) rather than a host request (such as the QMP command system_reset). (since 2.10)

reason: ShutdownCause

The ShutdownCause of the RESET. (since 4.0)

Since

0.12

Example:

<- { "event": "RESET",
     "data": { "guest": false, "reason": "guest-reset" },
     "timestamp": { "seconds": 1267041653, "microseconds": 9518 } }

STOP (Event)

Emitted when the virtual machine is stopped

Since

0.12

Example:

<- { "event": "STOP",
     "timestamp": { "seconds": 1267041730, "microseconds": 281295 } }

RESUME (Event)

Emitted when the virtual machine resumes execution

Since

0.12

Example:

<- { "event": "RESUME",
     "timestamp": { "seconds": 1271770767, "microseconds": 582542 } }

SUSPEND (Event)

Emitted when guest enters a hardware suspension state, for example, S3 state, which is sometimes called standby state

Since

1.1

Example:

<- { "event": "SUSPEND",
     "timestamp": { "seconds": 1344456160, "microseconds": 309119 } }

SUSPEND_DISK (Event)

Emitted when guest enters a hardware suspension state with data saved on disk, for example, S4 state, which is sometimes called hibernate state

Note

QEMU shuts down (similar to event SHUTDOWN) when entering this state.

Since

1.2

Example:

<- { "event": "SUSPEND_DISK",
     "timestamp": { "seconds": 1344456160, "microseconds": 309119 } }

WAKEUP (Event)

Emitted when the guest has woken up from suspend state and is running

Since

1.1

Example:

<- { "event": "WAKEUP",
     "timestamp": { "seconds": 1344522075, "microseconds": 745528 } }

WATCHDOG (Event)

Emitted when the watchdog device’s timer is expired

Arguments

action: WatchdogAction

action that has been taken

Note

If action is “reset”, “shutdown”, or “pause” the WATCHDOG event is followed respectively by the RESET, SHUTDOWN, or STOP events.

Note

This event is rate-limited.

Since

0.13

Example:

<- { "event": "WATCHDOG",
     "data": { "action": "reset" },
     "timestamp": { "seconds": 1267061043, "microseconds": 959568 } }

WatchdogAction (Enum)

An enumeration of the actions taken when the watchdog device’s timer is expired

Values

reset

system resets

shutdown

system shutdown, note that it is similar to powerdown, which tries to set to system status and notify guest

poweroff

system poweroff, the emulator program exits

pause

system pauses, similar to stop

debug

system enters debug state

none

nothing is done

inject-nmi

a non-maskable interrupt is injected into the first VCPU (all VCPUS on x86) (since 2.4)

Since

2.1

RebootAction (Enum)

Possible QEMU actions upon guest reboot

Values

reset

Reset the VM

shutdown

Shutdown the VM and exit, according to the shutdown action

Since

6.0

ShutdownAction (Enum)

Possible QEMU actions upon guest shutdown

Values

poweroff

Shutdown the VM and exit

pause

pause the VM

Since

6.0

PanicAction (Enum)

Values

none

Continue VM execution

pause

Pause the VM

shutdown

Shutdown the VM and exit, according to the shutdown action

exit-failure

Shutdown the VM and exit with nonzero status (since 7.1)

Since

6.0

watchdog-set-action (Command)

Set watchdog action.

Arguments

action: WatchdogAction

WatchdogAction action taken when watchdog timer expires.

Since

2.11

Example:

-> { "execute": "watchdog-set-action",
     "arguments": { "action": "inject-nmi" } }
<- { "return": {} }

set-action (Command)

Set the actions that will be taken by the emulator in response to guest events.

Arguments

reboot: RebootAction (optional)

RebootAction action taken on guest reboot.

shutdown: ShutdownAction (optional)

ShutdownAction action taken on guest shutdown.

panic: PanicAction (optional)

PanicAction action taken on guest panic.

watchdog: WatchdogAction (optional)

WatchdogAction action taken when watchdog timer expires.

Since

6.0

Example:

-> { "execute": "set-action",
     "arguments": { "reboot": "shutdown",
                    "shutdown" : "pause",
                    "panic": "pause",
                    "watchdog": "inject-nmi" } }
<- { "return": {} }

GUEST_PANICKED (Event)

Emitted when guest OS panic is detected

Arguments

action: GuestPanicAction

action that has been taken, currently always “pause”

info: GuestPanicInformation (optional)

information about a panic (since 2.9)

Since

1.5

Example:

<- { "event": "GUEST_PANICKED",
     "data": { "action": "pause" },
     "timestamp": { "seconds": 1648245231, "microseconds": 900001 } }

GUEST_CRASHLOADED (Event)

Emitted when guest OS crash loaded is detected

Arguments

action: GuestPanicAction

action that has been taken, currently always “run”

info: GuestPanicInformation (optional)

information about a panic

Since

5.0

Example:

<- { "event": "GUEST_CRASHLOADED",
     "data": { "action": "run" },
     "timestamp": { "seconds": 1648245259, "microseconds": 893771 } }

GUEST_PVSHUTDOWN (Event)

Emitted when guest submits a shutdown request via pvpanic interface

Since

9.1

Example:

<- { "event": "GUEST_PVSHUTDOWN",
     "timestamp": { "seconds": 1648245259, "microseconds": 893771 } }

GuestPanicAction (Enum)

An enumeration of the actions taken when guest OS panic is detected

Values

pause

system pauses

poweroff

system powers off (since 2.8)

run

system continues to run (since 5.0)

Since

2.1

GuestPanicInformationType (Enum)

An enumeration of the guest panic information types

Values

hyper-v

hyper-v guest panic information type

s390

s390 guest panic information type (Since: 2.12)

Since

2.9

GuestPanicInformation (Object)

Information about a guest panic

Members

type: GuestPanicInformationType

Crash type that defines the hypervisor specific information

The members of GuestPanicInformationHyperV when type is "hyper-v"

The members of GuestPanicInformationS390 when type is "s390"

Since

2.9

GuestPanicInformationHyperV (Object)

Hyper-V specific guest panic information (HV crash MSRs)

Members

arg1: int

for Windows, STOP code for the guest crash. For Linux, an error code.

arg2: int

for Windows, first argument of the STOP. For Linux, the guest OS ID, which has the kernel version in bits 16-47 and 0x8100 in bits 48-63.

arg3: int

for Windows, second argument of the STOP. For Linux, the program counter of the guest.

arg4: int

for Windows, third argument of the STOP. For Linux, the RAX register (x86) or the stack pointer (aarch64) of the guest.

arg5: int

for Windows, fourth argument of the STOP. For x86 Linux, the stack pointer of the guest.

Since

2.9

S390CrashReason (Enum)

Reason why the CPU is in a crashed state.

Values

unknown

no crash reason was set

disabled-wait

the CPU has entered a disabled wait state

extint-loop

clock comparator or cpu timer interrupt with new PSW enabled for external interrupts

pgmint-loop

program interrupt with BAD new PSW

opint-loop

operation exception interrupt with invalid code at the program interrupt new PSW

Since

2.12

GuestPanicInformationS390 (Object)

S390 specific guest panic information (PSW)

Members

core: int

core id of the CPU that crashed

psw-mask: int

control fields of guest PSW

psw-addr: int

guest instruction address

reason: S390CrashReason

guest crash reason

Since

2.12

MEMORY_FAILURE (Event)

Emitted when a memory failure occurs on host side.

Arguments

recipient: MemoryFailureRecipient

recipient is defined as MemoryFailureRecipient.

action: MemoryFailureAction

action that has been taken.

flags: MemoryFailureFlags

flags for MemoryFailureAction.

Since

5.2

Example:

<- { "event": "MEMORY_FAILURE",
     "data": { "recipient": "hypervisor",
               "action": "fatal",
               "flags": { "action-required": false,
                          "recursive": false } },
     "timestamp": { "seconds": 1267061043, "microseconds": 959568 } }

MemoryFailureRecipient (Enum)

Hardware memory failure occurs, handled by recipient.

Values

hypervisor

memory failure at QEMU process address space. (none guest memory, but used by QEMU itself).

guest

memory failure at guest memory,

Since

5.2

MemoryFailureAction (Enum)

Actions taken by QEMU in response to a hardware memory failure.

Values

ignore

the memory failure could be ignored. This will only be the case for action-optional failures.

inject

memory failure occurred in guest memory, the guest enabled MCE handling mechanism, and QEMU could inject the MCE into the guest successfully.

fatal

the failure is unrecoverable. This occurs for action-required failures if the recipient is the hypervisor; QEMU will exit.

reset

the failure is unrecoverable but confined to the guest. This occurs if the recipient is a guest guest which is not ready to handle memory failures.

Since

5.2

MemoryFailureFlags (Object)

Additional information on memory failures.

Members

action-required: boolean

whether a memory failure event is action-required or action-optional (e.g. a failure during memory scrub).

recursive: boolean

whether the failure occurred while the previous failure was still in progress.

Since

5.2

NotifyVmexitOption (Enum)

An enumeration of the options specified when enabling notify VM exit

Values

run

enable the feature, do nothing and continue if the notify VM exit happens.

internal-error

enable the feature, raise a internal error if the notify VM exit happens.

disable

disable the feature.

Since

7.2

Cryptography

QCryptoTLSCredsEndpoint (Enum)

The type of network endpoint that will be using the credentials. Most types of credential require different setup / structures depending on whether they will be used in a server versus a client.

Values

client

the network endpoint is acting as the client

server

the network endpoint is acting as the server

Since

2.5

QCryptoSecretFormat (Enum)

The data format that the secret is provided in

Values

raw

raw bytes. When encoded in JSON only valid UTF-8 sequences can be used

base64

arbitrary base64 encoded binary data

Since

2.6

QCryptoHashAlgo (Enum)

The supported algorithms for computing content digests

Values

md5

MD5. Should not be used in any new code, legacy compat only

sha1

SHA-1. Should not be used in any new code, legacy compat only

sha224

SHA-224. (since 2.7)

sha256

SHA-256. Current recommended strong hash.

sha384

SHA-384. (since 2.7)

sha512

SHA-512. (since 2.7)

ripemd160

RIPEMD-160. (since 2.7)

sm3

SM3. (since 9.2.0)

Since

2.6

QCryptoCipherAlgo (Enum)

The supported algorithms for content encryption ciphers

Values

aes-128

AES with 128 bit / 16 byte keys

aes-192

AES with 192 bit / 24 byte keys

aes-256

AES with 256 bit / 32 byte keys

des

DES with 56 bit / 8 byte keys. Do not use except in VNC. (since 6.1)

3des

3DES(EDE) with 192 bit / 24 byte keys (since 2.9)

cast5-128

Cast5 with 128 bit / 16 byte keys

serpent-128

Serpent with 128 bit / 16 byte keys

serpent-192

Serpent with 192 bit / 24 byte keys

serpent-256

Serpent with 256 bit / 32 byte keys

twofish-128

Twofish with 128 bit / 16 byte keys

twofish-192

Twofish with 192 bit / 24 byte keys

twofish-256

Twofish with 256 bit / 32 byte keys

sm4

SM4 with 128 bit / 16 byte keys (since 9.0)

Since

2.6

QCryptoCipherMode (Enum)

The supported modes for content encryption ciphers

Values

ecb

Electronic Code Book

cbc

Cipher Block Chaining

xts

XEX with tweaked code book and ciphertext stealing

ctr

Counter (Since 2.8)

Since

2.6

QCryptoIVGenAlgo (Enum)

The supported algorithms for generating initialization vectors for full disk encryption. The ‘plain’ generator should not be used for disks with sector numbers larger than 2^32, except where compatibility with pre-existing Linux dm-crypt volumes is required.

Values

plain

64-bit sector number truncated to 32-bits

plain64

64-bit sector number

essiv

64-bit sector number encrypted with a hash of the encryption key

Since

2.6

QCryptoBlockFormat (Enum)

The supported full disk encryption formats

Values

qcow

QCow/QCow2 built-in AES-CBC encryption. Use only for liberating data from old images.

luks

LUKS encryption format. Recommended for new images

Since

2.6

QCryptoBlockOptionsBase (Object)

The common options that apply to all full disk encryption formats

Members

format: QCryptoBlockFormat

the encryption format

Since

2.6

QCryptoBlockOptionsQCow (Object)

The options that apply to QCow/QCow2 AES-CBC encryption format

Members

key-secret: string (optional)

the ID of a QCryptoSecret object providing the decryption key. Mandatory except when probing image for metadata only.

Since

2.6

QCryptoBlockOptionsLUKS (Object)

The options that apply to LUKS encryption format

Members

key-secret: string (optional)

the ID of a QCryptoSecret object providing the decryption key. Mandatory except when probing image for metadata only.

Since

2.6

QCryptoBlockCreateOptionsLUKS (Object)

The options that apply to LUKS encryption format initialization

Members

cipher-alg: QCryptoCipherAlgo (optional)

the cipher algorithm for data encryption Currently defaults to ‘aes-256’.

cipher-mode: QCryptoCipherMode (optional)

the cipher mode for data encryption Currently defaults to ‘xts’

ivgen-alg: QCryptoIVGenAlgo (optional)

the initialization vector generator Currently defaults to ‘plain64’

ivgen-hash-alg: QCryptoHashAlgo (optional)

the initialization vector generator hash Currently defaults to ‘sha256’

hash-alg: QCryptoHashAlgo (optional)

the master key hash algorithm Currently defaults to ‘sha256’

iter-time: int (optional)

number of milliseconds to spend in PBKDF passphrase processing. Currently defaults to 2000. (since 2.8)

The members of QCryptoBlockOptionsLUKS

Since

2.6

QCryptoBlockOpenOptions (Object)

The options that are available for all encryption formats when opening an existing volume

Members

The members of QCryptoBlockOptionsBase

The members of QCryptoBlockOptionsQCow when format is "qcow"

The members of QCryptoBlockOptionsLUKS when format is "luks"

Since

2.6

QCryptoBlockCreateOptions (Object)

The options that are available for all encryption formats when initializing a new volume

Members

The members of QCryptoBlockOptionsBase

The members of QCryptoBlockOptionsQCow when format is "qcow"

The members of QCryptoBlockCreateOptionsLUKS when format is "luks"

Since

2.6

QCryptoBlockInfoBase (Object)

The common information that applies to all full disk encryption formats

Members

format: QCryptoBlockFormat

the encryption format

Since

2.7

QCryptoBlockInfoLUKSSlot (Object)

Information about the LUKS block encryption key slot options

Members

active: boolean

whether the key slot is currently in use

key-offset: int

offset to the key material in bytes

iters: int (optional)

number of PBKDF2 iterations for key material

stripes: int (optional)

number of stripes for splitting key material

Since

2.7

QCryptoBlockInfoLUKS (Object)

Information about the LUKS block encryption options

Members

cipher-alg: QCryptoCipherAlgo

the cipher algorithm for data encryption

cipher-mode: QCryptoCipherMode

the cipher mode for data encryption

ivgen-alg: QCryptoIVGenAlgo

the initialization vector generator

ivgen-hash-alg: QCryptoHashAlgo (optional)

the initialization vector generator hash

hash-alg: QCryptoHashAlgo

the master key hash algorithm

detached-header: boolean

whether the LUKS header is detached (Since 9.0)

payload-offset: int

offset to the payload data in bytes

master-key-iters: int

number of PBKDF2 iterations for key material

uuid: string

unique identifier for the volume

slots: array of QCryptoBlockInfoLUKSSlot

information about each key slot

Since

2.7

QCryptoBlockInfo (Object)

Information about the block encryption options

Members

The members of QCryptoBlockInfoBase

The members of QCryptoBlockInfoLUKS when format is "luks"

Since

2.7

QCryptoBlockLUKSKeyslotState (Enum)

Defines state of keyslots that are affected by the update

Values

active

The slots contain the given password and marked as active

inactive

The slots are erased (contain garbage) and marked as inactive

Since

5.1

QCryptoBlockAmendOptionsLUKS (Object)

This struct defines the update parameters that activate/de-activate set of keyslots

Members

state: QCryptoBlockLUKSKeyslotState

the desired state of the keyslots

new-secret: string (optional)

The ID of a QCryptoSecret object providing the password to be written into added active keyslots

old-secret: string (optional)

Optional (for deactivation only) If given will deactivate all keyslots that match password located in QCryptoSecret with this ID

iter-time: int (optional)

Optional (for activation only) Number of milliseconds to spend in PBKDF passphrase processing for the newly activated keyslot. Currently defaults to 2000.

keyslot: int (optional)

Optional. ID of the keyslot to activate/deactivate. For keyslot activation, keyslot should not be active already (this is unsafe to update an active keyslot), but possible if ‘force’ parameter is given. If keyslot is not given, first free keyslot will be written.

For keyslot deactivation, this parameter specifies the exact keyslot to deactivate

secret: string (optional)

Optional. The ID of a QCryptoSecret object providing the password to use to retrieve current master key. Defaults to the same secret that was used to open the image

Since

5.1

QCryptoBlockAmendOptions (Object)

The options that are available for all encryption formats when amending encryption settings

Members

The members of QCryptoBlockOptionsBase

The members of QCryptoBlockAmendOptionsLUKS when format is "luks"

Since

5.1

SecretCommonProperties (Object)

Properties for objects of classes derived from secret-common.

Members

format: QCryptoSecretFormat (optional)

the data format that the secret is provided in (default: raw)

keyid: string (optional)

the name of another secret that should be used to decrypt the provided data. If not present, the data is assumed to be unencrypted.

iv: string (optional)

the random initialization vector used for encryption of this particular secret. Should be a base64 encrypted string of the 16-byte IV. Mandatory if keyid is given. Ignored if keyid is absent.

Since

2.6

SecretProperties (Object)

Properties for secret objects.

Either data or file must be provided, but not both.

Members

data: string (optional)

the associated with the secret from

file: string (optional)

the filename to load the data associated with the secret from

The members of SecretCommonProperties

Since

2.6

SecretKeyringProperties (Object)

Properties for secret_keyring objects.

Members

serial: int

serial number that identifies a key to get from the kernel

The members of SecretCommonProperties

Since

5.1

If

CONFIG_SECRET_KEYRING

TlsCredsProperties (Object)

Properties for objects of classes derived from tls-creds.

Members

verify-peer: boolean (optional)

if true the peer credentials will be verified once the handshake is completed. This is a no-op for anonymous credentials. (default: true)

dir: string (optional)

the path of the directory that contains the credential files

endpoint: QCryptoTLSCredsEndpoint (optional)

whether the QEMU network backend that uses the credentials will be acting as a client or as a server (default: client)

priority: string (optional)

a gnutls priority string as described at https://gnutls.org/manual/html_node/Priority-Strings.html

Since

2.5

TlsCredsAnonProperties (Object)

Properties for tls-creds-anon objects.

Members

The members of TlsCredsProperties

Since

2.5

TlsCredsPskProperties (Object)

Properties for tls-creds-psk objects.

Members

username: string (optional)

the username which will be sent to the server. For clients only. If absent, “qemu” is sent and the property will read back as an empty string.

The members of TlsCredsProperties

Since

3.0

TlsCredsX509Properties (Object)

Properties for tls-creds-x509 objects.

Members

sanity-check: boolean (optional)

if true, perform some sanity checks before using the credentials (default: true)

passwordid: string (optional)

For the server-key.pem and client-key.pem files which contain sensitive private keys, it is possible to use an encrypted version by providing the passwordid parameter. This provides the ID of a previously created secret object containing the password for decryption.

The members of TlsCredsProperties

Since

2.5

QCryptoAkCipherAlgo (Enum)

The supported algorithms for asymmetric encryption ciphers

Values

rsa

RSA algorithm

Since

7.1

QCryptoAkCipherKeyType (Enum)

The type of asymmetric keys.

Values

public

public key

private

private key

Since

7.1

QCryptoRSAPaddingAlgo (Enum)

The padding algorithm for RSA.

Values

raw

no padding used

pkcs1

pkcs1#v1.5

Since

7.1

QCryptoAkCipherOptionsRSA (Object)

Specific parameters for RSA algorithm.

Members

hash-alg: QCryptoHashAlgo

QCryptoHashAlgo

padding-alg: QCryptoRSAPaddingAlgo

QCryptoRSAPaddingAlgo

Since

7.1

QCryptoAkCipherOptions (Object)

The options that are available for all asymmetric key algorithms when creating a new QCryptoAkCipher.

Members

alg: QCryptoAkCipherAlgo

encryption cipher algorithm

The members of QCryptoAkCipherOptionsRSA when alg is "rsa"

Since

7.1

Background jobs

JobType (Enum)

Type of a background job.

Values

commit

block commit job type, see “block-commit”

stream

block stream job type, see “block-stream”

mirror

drive mirror job type, see “drive-mirror”

backup

drive backup job type, see “drive-backup”

create

image creation job type, see “blockdev-create” (since 3.0)

amend

image options amend job type, see “x-blockdev-amend” (since 5.1)

snapshot-load

snapshot load job type, see “snapshot-load” (since 6.0)

snapshot-save

snapshot save job type, see “snapshot-save” (since 6.0)

snapshot-delete

snapshot delete job type, see “snapshot-delete” (since 6.0)

Since

1.7

JobStatus (Enum)

Indicates the present state of a given job in its lifetime.

Values

undefined

Erroneous, default state. Should not ever be visible.

created

The job has been created, but not yet started.

running

The job is currently running.

paused

The job is running, but paused. The pause may be requested by either the QMP user or by internal processes.

ready

The job is running, but is ready for the user to signal completion. This is used for long-running jobs like mirror that are designed to run indefinitely.

standby

The job is ready, but paused. This is nearly identical to paused. The job may return to ready or otherwise be canceled.

waiting

The job is waiting for other jobs in the transaction to converge to the waiting state. This status will likely not be visible for the last job in a transaction.

pending

The job has finished its work, but has finalization steps that it needs to make prior to completing. These changes will require manual intervention via job-finalize if auto-finalize was set to false. These pending changes may still fail.

aborting

The job is in the process of being aborted, and will finish with an error. The job will afterwards report that it is concluded. This status may not be visible to the management process.

concluded

The job has finished all work. If auto-dismiss was set to false, the job will remain in the query list until it is dismissed via job-dismiss.

null

The job is in the process of being dismantled. This state should not ever be visible externally.

Since

2.12

JobVerb (Enum)

Represents command verbs that can be applied to a job.

Values

cancel

see job-cancel

pause

see job-pause

resume

see job-resume

set-speed

see block-job-set-speed

complete

see job-complete

dismiss

see job-dismiss

finalize

see job-finalize

change

see block-job-change (since 8.2)

Since

2.12

JOB_STATUS_CHANGE (Event)

Emitted when a job transitions to a different status.

Arguments

id: string

The job identifier

status: JobStatus

The new job status

Since

3.0

job-pause (Command)

Pause an active job.

This command returns immediately after marking the active job for pausing. Pausing an already paused job is an error.

The job will pause as soon as possible, which means transitioning into the PAUSED state if it was RUNNING, or into STANDBY if it was READY. The corresponding JOB_STATUS_CHANGE event will be emitted.

Cancelling a paused job automatically resumes it.

Arguments

id: string

The job identifier.

Since

3.0

job-resume (Command)

Resume a paused job.

This command returns immediately after resuming a paused job. Resuming an already running job is an error.

Arguments

id: string

The job identifier.

Since

3.0

job-cancel (Command)

Instruct an active background job to cancel at the next opportunity. This command returns immediately after marking the active job for cancellation.

The job will cancel as soon as possible and then emit a JOB_STATUS_CHANGE event. Usually, the status will change to ABORTING, but it is possible that a job successfully completes (e.g. because it was almost done and there was no opportunity to cancel earlier than completing the job) and transitions to PENDING instead.

Arguments

id: string

The job identifier.

Since

3.0

job-complete (Command)

Manually trigger completion of an active job in the READY state.

Arguments

id: string

The job identifier.

Since

3.0

job-dismiss (Command)

Deletes a job that is in the CONCLUDED state. This command only needs to be run explicitly for jobs that don’t have automatic dismiss enabled.

This command will refuse to operate on any job that has not yet reached its terminal state, JOB_STATUS_CONCLUDED. For jobs that make use of JOB_READY event, job-cancel or job-complete will still need to be used as appropriate.

Arguments

id: string

The job identifier.

Since

3.0

job-finalize (Command)

Instructs all jobs in a transaction (or a single job if it is not part of any transaction) to finalize any graph changes and do any necessary cleanup. This command requires that all involved jobs are in the PENDING state.

For jobs in a transaction, instructing one job to finalize will force ALL jobs in the transaction to finalize, so it is only necessary to instruct a single member job to finalize.

Arguments

id: string

The identifier of any job in the transaction, or of a job that is not part of any transaction.

Since

3.0

JobInfo (Object)

Information about a job.

Members

id: string

The job identifier

type: JobType

The kind of job that is being performed

status: JobStatus

Current job state/status

current-progress: int

Progress made until now. The unit is arbitrary and the value can only meaningfully be used for the ratio of current-progress to total-progress. The value is monotonically increasing.

total-progress: int

Estimated current-progress value at the completion of the job. This value can arbitrarily change while the job is running, in both directions.

error: string (optional)

If this field is present, the job failed; if it is still missing in the CONCLUDED state, this indicates successful completion.

The value is a human-readable error message to describe the reason for the job failure. It should not be parsed by applications.

Since

3.0

query-jobs (Command)

Return information about jobs.

Returns

a list with a JobInfo for each active job

Since

3.0

Block devices

Block core (VM unrelated)

SnapshotInfo (Object)

Members

id: string

unique snapshot id

name: string

user chosen name

vm-state-size: int

size of the VM state

date-sec: int

UTC date of the snapshot in seconds

date-nsec: int

fractional part in nano seconds to be used with date-sec

vm-clock-sec: int

VM clock relative to boot in seconds

vm-clock-nsec: int

fractional part in nano seconds to be used with vm-clock-sec

icount: int (optional)

Current instruction count. Appears when execution record/replay is enabled. Used for “time-traveling” to match the moment in the recorded execution with the snapshots. This counter may be obtained through query-replay command (since 5.2)

Since

1.3

ImageInfoSpecificQCow2EncryptionBase (Object)

Members

format: BlockdevQcow2EncryptionFormat

The encryption format

Since

2.10

ImageInfoSpecificQCow2Encryption (Object)

Members

The members of ImageInfoSpecificQCow2EncryptionBase

The members of QCryptoBlockInfoLUKS when format is "luks"

Since

2.10

ImageInfoSpecificQCow2 (Object)

Members

compat: string

compatibility level

data-file: string (optional)

the filename of the external data file that is stored in the image and used as a default for opening the image (since: 4.0)

data-file-raw: boolean (optional)

True if the external data file must stay valid as a standalone (read-only) raw image without looking at qcow2 metadata (since: 4.0)

extended-l2: boolean (optional)

true if the image has extended L2 entries; only valid for compat >= 1.1 (since 5.2)

lazy-refcounts: boolean (optional)

on or off; only valid for compat >= 1.1

corrupt: boolean (optional)

true if the image has been marked corrupt; only valid for compat >= 1.1 (since 2.2)

refcount-bits: int

width of a refcount entry in bits (since 2.3)

encrypt: ImageInfoSpecificQCow2Encryption (optional)

details about encryption parameters; only set if image is encrypted (since 2.10)

bitmaps: array of Qcow2BitmapInfo (optional)

A list of qcow2 bitmap details (since 4.0)

compression-type: Qcow2CompressionType

the image cluster compression method (since 5.1)

Since

1.7

ImageInfoSpecificVmdk (Object)

Members

create-type: string

The create type of VMDK image

cid: int

Content id of image

parent-cid: int

Parent VMDK image’s cid

extents: array of VmdkExtentInfo

List of extent files

Since

1.7

VmdkExtentInfo (Object)

Information about a VMDK extent file

Members

filename: string

Name of the extent file

format: string

Extent type (e.g. FLAT or SPARSE)

virtual-size: int

Number of bytes covered by this extent

cluster-size: int (optional)

Cluster size in bytes (for non-flat extents)

compressed: boolean (optional)

Whether this extent contains compressed data

Since

8.0

ImageInfoSpecificRbd (Object)

Members

encryption-format: RbdImageEncryptionFormat (optional)

Image encryption format

Since

6.1

ImageInfoSpecificFile (Object)

Members

extent-size-hint: int (optional)

Extent size hint (if available)

Since

8.0

ImageInfoSpecificKind (Enum)

Values

luks

Since 2.7

rbd

Since 6.1

file

Since 8.0

qcow2

Not documented

vmdk

Not documented

Since

1.7

ImageInfoSpecificQCow2Wrapper (Object)

Members

data: ImageInfoSpecificQCow2

image information specific to QCOW2

Since

1.7

ImageInfoSpecificVmdkWrapper (Object)

Members

data: ImageInfoSpecificVmdk

image information specific to VMDK

Since

6.1

ImageInfoSpecificLUKSWrapper (Object)

Members

data: QCryptoBlockInfoLUKS

image information specific to LUKS

Since

2.7

ImageInfoSpecificRbdWrapper (Object)

Members

data: ImageInfoSpecificRbd

image information specific to RBD

Since

6.1

ImageInfoSpecificFileWrapper (Object)

Members

data: ImageInfoSpecificFile

image information specific to files

Since

8.0

ImageInfoSpecific (Object)

A discriminated record of image format specific information structures.

Members

type: ImageInfoSpecificKind

block driver name

The members of ImageInfoSpecificQCow2Wrapper when type is "qcow2"

The members of ImageInfoSpecificVmdkWrapper when type is "vmdk"

The members of ImageInfoSpecificLUKSWrapper when type is "luks"

The members of ImageInfoSpecificRbdWrapper when type is "rbd"

The members of ImageInfoSpecificFileWrapper when type is "file"

Since

1.7

BlockNodeInfo (Object)

Information about a QEMU image file

Members

filename: string

name of the image file

format: string

format of the image file

virtual-size: int

maximum capacity in bytes of the image

actual-size: int (optional)

actual size on disk in bytes of the image

dirty-flag: boolean (optional)

true if image is not cleanly closed

cluster-size: int (optional)

size of a cluster in bytes

encrypted: boolean (optional)

true if the image is encrypted

compressed: boolean (optional)

true if the image is compressed (Since 1.7)

backing-filename: string (optional)

name of the backing file

full-backing-filename: string (optional)

full path of the backing file

backing-filename-format: string (optional)

the format of the backing file

snapshots: array of SnapshotInfo (optional)

list of VM snapshots

format-specific: ImageInfoSpecific (optional)

structure supplying additional format-specific information (since 1.7)

Since

8.0

ImageInfo (Object)

Information about a QEMU image file, and potentially its backing image

Members

backing-image: ImageInfo (optional)

info of the backing image

The members of BlockNodeInfo

Since

1.3

BlockChildInfo (Object)

Information about all nodes in the block graph starting at some node, annotated with information about that node in relation to its parent.

Members

name: string

Child name of the root node in the BlockGraphInfo struct, in its role as the child of some undescribed parent node

info: BlockGraphInfo

Block graph information starting at this node

Since

8.0

BlockGraphInfo (Object)

Information about all nodes in a block (sub)graph in the form of BlockNodeInfo data. The base BlockNodeInfo struct contains the information for the (sub)graph’s root node.

Members

children: array of BlockChildInfo

Array of links to this node’s child nodes’ information

The members of BlockNodeInfo

Since

8.0

ImageCheck (Object)

Information about a QEMU image file check

Members

filename: string

name of the image file checked

format: string

format of the image file checked

check-errors: int

number of unexpected errors occurred during check

image-end-offset: int (optional)

offset (in bytes) where the image ends, this field is present if the driver for the image format supports it

corruptions: int (optional)

number of corruptions found during the check if any

leaks: int (optional)

number of leaks found during the check if any

corruptions-fixed: int (optional)

number of corruptions fixed during the check if any

leaks-fixed: int (optional)

number of leaks fixed during the check if any

total-clusters: int (optional)

total number of clusters, this field is present if the driver for the image format supports it

allocated-clusters: int (optional)

total number of allocated clusters, this field is present if the driver for the image format supports it

fragmented-clusters: int (optional)

total number of fragmented clusters, this field is present if the driver for the image format supports it

compressed-clusters: int (optional)

total number of compressed clusters, this field is present if the driver for the image format supports it

Since

1.4

MapEntry (Object)

Mapping information from a virtual block range to a host file range

Members

start: int

virtual (guest) offset of the first byte described by this entry

length: int

the number of bytes of the mapped virtual range

data: boolean

reading the image will actually read data from a file (in particular, if offset is present this means that the sectors are not simply preallocated, but contain actual data in raw format)

zero: boolean

whether the virtual blocks read as zeroes

compressed: boolean

true if the data is stored compressed (since 8.2)

depth: int

number of layers (0 = top image, 1 = top image’s backing file, …, n - 1 = bottom image (where n is the number of images in the chain)) before reaching one for which the range is allocated

present: boolean

true if this layer provides the data, false if adding a backing layer could impact this region (since 6.1)

offset: int (optional)

if present, the image file stores the data for this range in raw format at the given (host) offset

filename: string (optional)

filename that is referred to by offset

Since

2.6

BlockdevCacheInfo (Object)

Cache mode information for a block device

Members

writeback: boolean

true if writeback mode is enabled

direct: boolean

true if the host page cache is bypassed (O_DIRECT)

no-flush: boolean

true if flush requests are ignored for the device

Since

2.3

BlockDeviceInfo (Object)

Information about the backing device for a block device.

Members

file: string

the filename of the backing device

node-name: string (optional)

the name of the block driver node (Since 2.0)

ro: boolean

true if the backing device was open read-only

drv: string

the name of the block format used to open the backing device. As of 0.14 this can be: ‘blkdebug’, ‘bochs’, ‘cloop’, ‘cow’, ‘dmg’, ‘file’, ‘file’, ‘ftp’, ‘ftps’, ‘host_cdrom’, ‘host_device’, ‘http’, ‘https’, ‘luks’, ‘nbd’, ‘parallels’, ‘qcow’, ‘qcow2’, ‘raw’, ‘vdi’, ‘vmdk’, ‘vpc’, ‘vvfat’ 2.2: ‘archipelago’ added, ‘cow’ dropped 2.3: ‘host_floppy’ deprecated 2.5: ‘host_floppy’ dropped 2.6: ‘luks’ added 2.8: ‘replication’ added, ‘tftp’ dropped 2.9: ‘archipelago’ dropped

backing_file: string (optional)

the name of the backing file (for copy-on-write)

backing_file_depth: int

number of files in the backing file chain (since: 1.2)

encrypted: boolean

true if the backing device is encrypted

detect_zeroes: BlockdevDetectZeroesOptions

detect and optimize zero writes (Since 2.1)

bps: int

total throughput limit in bytes per second is specified

bps_rd: int

read throughput limit in bytes per second is specified

bps_wr: int

write throughput limit in bytes per second is specified

iops: int

total I/O operations per second is specified

iops_rd: int

read I/O operations per second is specified

iops_wr: int

write I/O operations per second is specified

image: ImageInfo

the info of image used (since: 1.6)

bps_max: int (optional)

total throughput limit during bursts, in bytes (Since 1.7)

bps_rd_max: int (optional)

read throughput limit during bursts, in bytes (Since 1.7)

bps_wr_max: int (optional)

write throughput limit during bursts, in bytes (Since 1.7)

iops_max: int (optional)

total I/O operations per second during bursts, in bytes (Since 1.7)

iops_rd_max: int (optional)

read I/O operations per second during bursts, in bytes (Since 1.7)

iops_wr_max: int (optional)

write I/O operations per second during bursts, in bytes (Since 1.7)

bps_max_length: int (optional)

maximum length of the bps_max burst period, in seconds. (Since 2.6)

bps_rd_max_length: int (optional)

maximum length of the bps_rd_max burst period, in seconds. (Since 2.6)

bps_wr_max_length: int (optional)

maximum length of the bps_wr_max burst period, in seconds. (Since 2.6)

iops_max_length: int (optional)

maximum length of the iops burst period, in seconds. (Since 2.6)

iops_rd_max_length: int (optional)

maximum length of the iops_rd_max burst period, in seconds. (Since 2.6)

iops_wr_max_length: int (optional)

maximum length of the iops_wr_max burst period, in seconds. (Since 2.6)

iops_size: int (optional)

an I/O size in bytes (Since 1.7)

group: string (optional)

throttle group name (Since 2.4)

cache: BlockdevCacheInfo

the cache mode used for the block device (since: 2.3)

write_threshold: int

configured write threshold for the device. 0 if disabled. (Since 2.3)

dirty-bitmaps: array of BlockDirtyInfo (optional)

dirty bitmaps information (only present if node has one or more dirty bitmaps) (Since 4.2)

Since

0.14

BlockDeviceIoStatus (Enum)

An enumeration of block device I/O status.

Values

ok

The last I/O operation has succeeded

failed

The last I/O operation has failed

nospace

The last I/O operation has failed due to a no-space condition

Since

1.0

BlockDirtyInfo (Object)

Block dirty bitmap information.

Members

name: string (optional)

the name of the dirty bitmap (Since 2.4)

count: int

number of dirty bytes according to the dirty bitmap

granularity: int

granularity of the dirty bitmap in bytes (since 1.4)

recording: boolean

true if the bitmap is recording new writes from the guest. (since 4.0)

busy: boolean

true if the bitmap is in-use by some operation (NBD or jobs) and cannot be modified via QMP or used by another operation. (since 4.0)

persistent: boolean

true if the bitmap was stored on disk, is scheduled to be stored on disk, or both. (since 4.0)

inconsistent: boolean (optional)

true if this is a persistent bitmap that was improperly stored. Implies persistent to be true; recording and busy to be false. This bitmap cannot be used. To remove it, use block-dirty-bitmap-remove. (Since 4.0)

Since

1.3

Qcow2BitmapInfoFlags (Enum)

An enumeration of flags that a bitmap can report to the user.

Values

in-use

This flag is set by any process actively modifying the qcow2 file, and cleared when the updated bitmap is flushed to the qcow2 image. The presence of this flag in an offline image means that the bitmap was not saved correctly after its last usage, and may contain inconsistent data.

auto

The bitmap must reflect all changes of the virtual disk by any application that would write to this qcow2 file.

Since

4.0

Qcow2BitmapInfo (Object)

Qcow2 bitmap information.

Members

name: string

the name of the bitmap

granularity: int

granularity of the bitmap in bytes

flags: array of Qcow2BitmapInfoFlags

flags of the bitmap

Since

4.0

BlockLatencyHistogramInfo (Object)

Block latency histogram.

Members

boundaries: array of int

list of interval boundary values in nanoseconds, all greater than zero and in ascending order. For example, the list [10, 50, 100] produces the following histogram intervals: [0, 10), [10, 50), [50, 100), [100, +inf).

bins: array of int

list of io request counts corresponding to histogram intervals, one more element than boundaries has. For the example above, bins may be something like [3, 1, 5, 2], and corresponding histogram looks like:

5|           *
4|           *
3| *         *
2| *         *    *
1| *    *    *    *
 +------------------
     10   50   100

Since

4.0

BlockInfo (Object)

Block device information. This structure describes a virtual device and the backing device associated with it.

Members

device: string

The device name associated with the virtual device.

qdev: string (optional)

The qdev ID, or if no ID is assigned, the QOM path of the block device. (since 2.10)

type: string

This field is returned only for compatibility reasons, it should not be used (always returns ‘unknown’)

removable: boolean

True if the device supports removable media.

locked: boolean

True if the guest has locked this device from having its media removed

tray_open: boolean (optional)

True if the device’s tray is open (only present if it has a tray)

io-status: BlockDeviceIoStatus (optional)

BlockDeviceIoStatus. Only present if the device supports it and the VM is configured to stop on errors (supported device models: virtio-blk, IDE, SCSI except scsi-generic)

inserted: BlockDeviceInfo (optional)

BlockDeviceInfo describing the device if media is present

Since

0.14

BlockMeasureInfo (Object)

Image file size calculation information. This structure describes the size requirements for creating a new image file.

The size requirements depend on the new image file format. File size always equals virtual disk size for the ‘raw’ format, even for sparse POSIX files. Compact formats such as ‘qcow2’ represent unallocated and zero regions efficiently so file size may be smaller than virtual disk size.

The values are upper bounds that are guaranteed to fit the new image file. Subsequent modification, such as internal snapshot or further bitmap creation, may require additional space and is not covered here.

Members

required: int

Size required for a new image file, in bytes, when copying just allocated guest-visible contents.

fully-allocated: int

Image file size, in bytes, once data has been written to all sectors, when copying just guest-visible contents.

bitmaps: int (optional)

Additional size required if all the top-level bitmap metadata in the source image were to be copied to the destination, present only when source and destination both support persistent bitmaps. (since 5.1)

Since

2.10

query-block (Command)

Get a list of BlockInfo for all virtual block devices.

Returns

a list of BlockInfo describing each virtual block device. Filter nodes that were created implicitly are skipped over.

Since

0.14

Example:

-> { "execute": "query-block" }
<- {
      "return":[
         {
            "io-status": "ok",
            "device":"ide0-hd0",
            "locked":false,
            "removable":false,
            "inserted":{
               "ro":false,
               "drv":"qcow2",
               "encrypted":false,
               "file":"disks/test.qcow2",
               "backing_file_depth":1,
               "bps":1000000,
               "bps_rd":0,
               "bps_wr":0,
               "iops":1000000,
               "iops_rd":0,
               "iops_wr":0,
               "bps_max": 8000000,
               "bps_rd_max": 0,
               "bps_wr_max": 0,
               "iops_max": 0,
               "iops_rd_max": 0,
               "iops_wr_max": 0,
               "iops_size": 0,
               "detect_zeroes": "on",
               "write_threshold": 0,
               "image":{
                  "filename":"disks/test.qcow2",
                  "format":"qcow2",
                  "virtual-size":2048000,
                  "backing_file":"base.qcow2",
                  "full-backing-filename":"disks/base.qcow2",
                  "backing-filename-format":"qcow2",
                  "snapshots":[
                     {
                        "id": "1",
                        "name": "snapshot1",
                        "vm-state-size": 0,
                        "date-sec": 10000200,
                        "date-nsec": 12,
                        "vm-clock-sec": 206,
                        "vm-clock-nsec": 30
                     }
                  ],
                  "backing-image":{
                      "filename":"disks/base.qcow2",
                      "format":"qcow2",
                      "virtual-size":2048000
                  }
               }
            },
            "qdev": "ide_disk",
            "type":"unknown"
         },
         {
            "io-status": "ok",
            "device":"ide1-cd0",
            "locked":false,
            "removable":true,
            "qdev": "/machine/unattached/device[23]",
            "tray_open": false,
            "type":"unknown"
         },
         {
            "device":"floppy0",
            "locked":false,
            "removable":true,
            "qdev": "/machine/unattached/device[20]",
            "type":"unknown"
         },
         {
            "device":"sd0",
            "locked":false,
            "removable":true,
            "type":"unknown"
         }
      ]
   }

BlockDeviceTimedStats (Object)

Statistics of a block device during a given interval of time.

Members

interval_length: int

Interval used for calculating the statistics, in seconds.

min_rd_latency_ns: int

Minimum latency of read operations in the defined interval, in nanoseconds.

min_wr_latency_ns: int

Minimum latency of write operations in the defined interval, in nanoseconds.

min_zone_append_latency_ns: int

Minimum latency of zone append operations in the defined interval, in nanoseconds (since 8.1)

min_flush_latency_ns: int

Minimum latency of flush operations in the defined interval, in nanoseconds.

max_rd_latency_ns: int

Maximum latency of read operations in the defined interval, in nanoseconds.

max_wr_latency_ns: int

Maximum latency of write operations in the defined interval, in nanoseconds.

max_zone_append_latency_ns: int

Maximum latency of zone append operations in the defined interval, in nanoseconds (since 8.1)

max_flush_latency_ns: int

Maximum latency of flush operations in the defined interval, in nanoseconds.

avg_rd_latency_ns: int

Average latency of read operations in the defined interval, in nanoseconds.

avg_wr_latency_ns: int

Average latency of write operations in the defined interval, in nanoseconds.

avg_zone_append_latency_ns: int

Average latency of zone append operations in the defined interval, in nanoseconds (since 8.1)

avg_flush_latency_ns: int

Average latency of flush operations in the defined interval, in nanoseconds.

avg_rd_queue_depth: number

Average number of pending read operations in the defined interval.

avg_wr_queue_depth: number

Average number of pending write operations in the defined interval.

avg_zone_append_queue_depth: number

Average number of pending zone append operations in the defined interval (since 8.1).

Since

2.5

BlockDeviceStats (Object)

Statistics of a virtual block device or a block backing device.

Members

rd_bytes: int

The number of bytes read by the device.

wr_bytes: int

The number of bytes written by the device.

zone_append_bytes: int

The number of bytes appended by the zoned devices (since 8.1)

unmap_bytes: int

The number of bytes unmapped by the device (Since 4.2)

rd_operations: int

The number of read operations performed by the device.

wr_operations: int

The number of write operations performed by the device.

zone_append_operations: int

The number of zone append operations performed by the zoned devices (since 8.1)

flush_operations: int

The number of cache flush operations performed by the device (since 0.15)

unmap_operations: int

The number of unmap operations performed by the device (Since 4.2)

rd_total_time_ns: int

Total time spent on reads in nanoseconds (since 0.15).

wr_total_time_ns: int

Total time spent on writes in nanoseconds (since 0.15).

zone_append_total_time_ns: int

Total time spent on zone append writes in nanoseconds (since 8.1)

flush_total_time_ns: int

Total time spent on cache flushes in nanoseconds (since 0.15).

unmap_total_time_ns: int

Total time spent on unmap operations in nanoseconds (Since 4.2)

wr_highest_offset: int

The offset after the greatest byte written to the device. The intended use of this information is for growable sparse files (like qcow2) that are used on top of a physical device.

rd_merged: int

Number of read requests that have been merged into another request (Since 2.3).

wr_merged: int

Number of write requests that have been merged into another request (Since 2.3).

zone_append_merged: int

Number of zone append requests that have been merged into another request (since 8.1)

unmap_merged: int

Number of unmap requests that have been merged into another request (Since 4.2)

idle_time_ns: int (optional)

Time since the last I/O operation, in nanoseconds. If the field is absent it means that there haven’t been any operations yet (Since 2.5).

failed_rd_operations: int

The number of failed read operations performed by the device (Since 2.5)

failed_wr_operations: int

The number of failed write operations performed by the device (Since 2.5)

failed_zone_append_operations: int

The number of failed zone append write operations performed by the zoned devices (since 8.1)

failed_flush_operations: int

The number of failed flush operations performed by the device (Since 2.5)

failed_unmap_operations: int

The number of failed unmap operations performed by the device (Since 4.2)

invalid_rd_operations: int

The number of invalid read operations performed by the device (Since 2.5)

invalid_wr_operations: int

The number of invalid write operations performed by the device (Since 2.5)

invalid_zone_append_operations: int

The number of invalid zone append operations performed by the zoned device (since 8.1)

invalid_flush_operations: int

The number of invalid flush operations performed by the device (Since 2.5)

invalid_unmap_operations: int

The number of invalid unmap operations performed by the device (Since 4.2)

account_invalid: boolean

Whether invalid operations are included in the last access statistics (Since 2.5)

account_failed: boolean

Whether failed operations are included in the latency and last access statistics (Since 2.5)

timed_stats: array of BlockDeviceTimedStats

Statistics specific to the set of previously defined intervals of time (Since 2.5)

rd_latency_histogram: BlockLatencyHistogramInfo (optional)

BlockLatencyHistogramInfo. (Since 4.0)

wr_latency_histogram: BlockLatencyHistogramInfo (optional)

BlockLatencyHistogramInfo. (Since 4.0)

zone_append_latency_histogram: BlockLatencyHistogramInfo (optional)

BlockLatencyHistogramInfo. (since 8.1)

flush_latency_histogram: BlockLatencyHistogramInfo (optional)

BlockLatencyHistogramInfo. (Since 4.0)

Since

0.14

BlockStatsSpecificFile (Object)

File driver statistics

Members

discard-nb-ok: int

The number of successful discard operations performed by the driver.

discard-nb-failed: int

The number of failed discard operations performed by the driver.

discard-bytes-ok: int

The number of bytes discarded by the driver.

Since

4.2

BlockStatsSpecificNvme (Object)

NVMe driver statistics

Members

completion-errors: int

The number of completion errors.

aligned-accesses: int

The number of aligned accesses performed by the driver.

unaligned-accesses: int

The number of unaligned accesses performed by the driver.

Since

5.2

BlockStatsSpecific (Object)

Block driver specific statistics

Members

driver: BlockdevDriver

block driver name

The members of BlockStatsSpecificFile when driver is "file"

The members of BlockStatsSpecificFile when driver is "host_device" (If: HAVE_HOST_BLOCK_DEVICE)

The members of BlockStatsSpecificNvme when driver is "nvme"

Since

4.2

BlockStats (Object)

Statistics of a virtual block device or a block backing device.

Members

device: string (optional)

If the stats are for a virtual block device, the name corresponding to the virtual block device.

node-name: string (optional)

The node name of the device. (Since 2.3)

qdev: string (optional)

The qdev ID, or if no ID is assigned, the QOM path of the block device. (since 3.0)

stats: BlockDeviceStats

A BlockDeviceStats for the device.

driver-specific: BlockStatsSpecific (optional)

Optional driver-specific stats. (Since 4.2)

parent: BlockStats (optional)

This describes the file block device if it has one. Contains recursively the statistics of the underlying protocol (e.g. the host file for a qcow2 image). If there is no underlying protocol, this field is omitted

backing: BlockStats (optional)

This describes the backing block device if it has one. (Since 2.0)

Since

0.14

query-blockstats (Command)

Query the BlockStats for all virtual block devices.

Arguments

query-nodes: boolean (optional)

If true, the command will query all the block nodes that have a node name, in a list which will include “parent” information, but not “backing”. If false or omitted, the behavior is as before - query all the device backends, recursively including their “parent” and “backing”. Filter nodes that were created implicitly are skipped over in this mode. (Since 2.3)

Returns

A list of BlockStats for each virtual block devices.

Since

0.14

Example:

-> { "execute": "query-blockstats" }
<- {
      "return":[
         {
            "device":"ide0-hd0",
            "parent":{
               "stats":{
                  "wr_highest_offset":3686448128,
                  "wr_bytes":9786368,
                  "wr_operations":751,
                  "rd_bytes":122567168,
                  "rd_operations":36772
                  "wr_total_times_ns":313253456
                  "rd_total_times_ns":3465673657
                  "flush_total_times_ns":49653
                  "flush_operations":61,
                  "rd_merged":0,
                  "wr_merged":0,
                  "idle_time_ns":2953431879,
                  "account_invalid":true,
                  "account_failed":false
               }
            },
            "stats":{
               "wr_highest_offset":2821110784,
               "wr_bytes":9786368,
               "wr_operations":692,
               "rd_bytes":122739200,
               "rd_operations":36604
               "flush_operations":51,
               "wr_total_times_ns":313253456
               "rd_total_times_ns":3465673657
               "flush_total_times_ns":49653,
               "rd_merged":0,
               "wr_merged":0,
               "idle_time_ns":2953431879,
               "account_invalid":true,
               "account_failed":false
            },
            "qdev": "/machine/unattached/device[23]"
         },
         {
            "device":"ide1-cd0",
            "stats":{
               "wr_highest_offset":0,
               "wr_bytes":0,
               "wr_operations":0,
               "rd_bytes":0,
               "rd_operations":0
               "flush_operations":0,
               "wr_total_times_ns":0
               "rd_total_times_ns":0
               "flush_total_times_ns":0,
               "rd_merged":0,
               "wr_merged":0,
               "account_invalid":false,
               "account_failed":false
            },
            "qdev": "/machine/unattached/device[24]"
         },
         {
            "device":"floppy0",
            "stats":{
               "wr_highest_offset":0,
               "wr_bytes":0,
               "wr_operations":0,
               "rd_bytes":0,
               "rd_operations":0
               "flush_operations":0,
               "wr_total_times_ns":0
               "rd_total_times_ns":0
               "flush_total_times_ns":0,
               "rd_merged":0,
               "wr_merged":0,
               "account_invalid":false,
               "account_failed":false
            },
            "qdev": "/machine/unattached/device[16]"
         },
         {
            "device":"sd0",
            "stats":{
               "wr_highest_offset":0,
               "wr_bytes":0,
               "wr_operations":0,
               "rd_bytes":0,
               "rd_operations":0
               "flush_operations":0,
               "wr_total_times_ns":0
               "rd_total_times_ns":0
               "flush_total_times_ns":0,
               "rd_merged":0,
               "wr_merged":0,
               "account_invalid":false,
               "account_failed":false
            }
         }
      ]
   }

BlockdevOnError (Enum)

An enumeration of possible behaviors for errors on I/O operations. The exact meaning depends on whether the I/O was initiated by a guest or by a block job

Values

report

for guest operations, report the error to the guest; for jobs, cancel the job

ignore

ignore the error, only report a QMP event (BLOCK_IO_ERROR or BLOCK_JOB_ERROR). The backup, mirror and commit block jobs retry the failing request later and may still complete successfully. The stream block job continues to stream and will complete with an error.

enospc

same as stop on ENOSPC, same as report otherwise.

stop

for guest operations, stop the virtual machine; for jobs, pause the job

auto

inherit the error handling policy of the backend (since: 2.7)

Since

1.3

MirrorSyncMode (Enum)

An enumeration of possible behaviors for the initial synchronization phase of storage mirroring.

Values

top

copies data in the topmost image to the destination

full

copies data from all images to the destination

none

only copy data written from now on

incremental

only copy data described by the dirty bitmap. (since: 2.4)

bitmap

only copy data described by the dirty bitmap. (since: 4.2) Behavior on completion is determined by the BitmapSyncMode.

Since

1.3

BitmapSyncMode (Enum)

An enumeration of possible behaviors for the synchronization of a bitmap when used for data copy operations.

Values

on-success

The bitmap is only synced when the operation is successful. This is the behavior always used for ‘INCREMENTAL’ backups.

never

The bitmap is never synchronized with the operation, and is treated solely as a read-only manifest of blocks to copy.

always

The bitmap is always synchronized with the operation, regardless of whether or not the operation was successful.

Since

4.2

MirrorCopyMode (Enum)

An enumeration whose values tell the mirror block job when to trigger writes to the target.

Values

background

copy data in background only.

write-blocking

when data is written to the source, write it (synchronously) to the target as well. In addition, data is copied in background just like in background mode.

Since

3.0

BlockJobInfoMirror (Object)

Information specific to mirror block jobs.

Members

actively-synced: boolean

Whether the source is actively synced to the target, i.e. same data and new writes are done synchronously to both.

Since

8.2

BlockJobInfo (Object)

Information about a long-running block device operation.

Members

type: JobType

the job type (‘stream’ for image streaming)

device: string

The job identifier. Originally the device name but other values are allowed since QEMU 2.7

len: int

Estimated offset value at the completion of the job. This value can arbitrarily change while the job is running, in both directions.

offset: int

Progress made until now. The unit is arbitrary and the value can only meaningfully be used for the ratio of offset to len. The value is monotonically increasing.

busy: boolean

false if the job is known to be in a quiescent state, with no pending I/O. (Since 1.3)

paused: boolean

whether the job is paused or, if busy is true, will pause itself as soon as possible. (Since 1.3)

speed: int

the rate limit, bytes per second

io-status: BlockDeviceIoStatus

the status of the job (since 1.3)

ready: boolean

true if the job may be completed (since 2.2)

status: JobStatus

Current job state/status (since 2.12)

auto-finalize: boolean

Job will finalize itself when PENDING, moving to the CONCLUDED state. (since 2.12)

auto-dismiss: boolean

Job will dismiss itself when CONCLUDED, moving to the NULL state and disappearing from the query list. (since 2.12)

error: string (optional)

Error information if the job did not complete successfully. Not set if the job completed successfully. (since 2.12.1)

The members of BlockJobInfoMirror when type is "mirror"

Since

1.1

query-block-jobs (Command)

Return information about long-running block device operations.

Returns

a list of BlockJobInfo for each active block job

Since

1.1

block_resize (Command)

Resize a block image while a guest is running.

Either device or node-name must be set but not both.

Arguments

device: string (optional)

the name of the device to get the image resized

node-name: string (optional)

graph node name to get the image resized (Since 2.0)

size: int

new image size in bytes

Errors

• If device is not a valid block device, DeviceNotFound

Since

0.14

Example:

-> { "execute": "block_resize",
     "arguments": { "device": "scratch", "size": 1073741824 } }
<- { "return": {} }

NewImageMode (Enum)

An enumeration that tells QEMU how to set the backing file path in a new image file.

Values

existing

QEMU should look for an existing image file.

absolute-paths

QEMU should create a new image with absolute paths for the backing file. If there is no backing file available, the new image will not be backed either.

Since

1.1

BlockdevSnapshotSync (Object)

Either device or node-name must be set but not both.

Members

device: string (optional)

the name of the device to take a snapshot of.

node-name: string (optional)

graph node name to generate the snapshot from (Since 2.0)

snapshot-file: string

the target of the new overlay image. If the file exists, or if it is a device, the overlay will be created in the existing file/device. Otherwise, a new file will be created.

snapshot-node-name: string (optional)

the graph node name of the new image (Since 2.0)

format: string (optional)

the format of the overlay image, default is ‘qcow2’.

mode: NewImageMode (optional)

whether and how QEMU should create a new image, default is ‘absolute-paths’.

BlockdevSnapshot (Object)

Members

node: string

device or node name that will have a snapshot taken.

overlay: string

reference to the existing block device that will become the overlay of node, as part of taking the snapshot. It must not have a current backing file (this can be achieved by passing “backing”: null to blockdev-add).

Since

2.5

BackupPerf (Object)

Optional parameters for backup. These parameters don’t affect functionality, but may significantly affect performance.

Members

use-copy-range: boolean (optional)

Use copy offloading. Default false.

max-workers: int (optional)

Maximum number of parallel requests for the sustained background copying process. Doesn’t influence copy-before-write operations. Default 64.

max-chunk: int (optional)

Maximum request length for the sustained background copying process. Doesn’t influence copy-before-write operations. 0 means unlimited. If max-chunk is non-zero then it should not be less than job cluster size which is calculated as maximum of target image cluster size and 64k. Default 0.

min-cluster-size: int (optional)

Minimum size of blocks used by copy-before-write and background copy operations. Has to be a power of 2. No effect if smaller than the maximum of the target’s cluster size and 64 KiB. Default 0. (Since 9.2)

Since

6.0

BackupCommon (Object)

Members

job-id: string (optional)

identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)

device: string

the device name or node-name of a root node which should be copied.

sync: MirrorSyncMode

what parts of the disk image should be copied to the destination (all the disk, only the sectors allocated in the topmost image, from a dirty bitmap, or only new I/O).

speed: int (optional)

the maximum speed, in bytes per second. The default is 0, for unlimited.

bitmap: string (optional)

The name of a dirty bitmap to use. Must be present if sync is “bitmap” or “incremental”. Can be present if sync is “full” or “top”. Must not be present otherwise. (Since 2.4 (drive-backup), 3.1 (blockdev-backup))

bitmap-mode: BitmapSyncMode (optional)

Specifies the type of data the bitmap should contain after the operation concludes. Must be present if a bitmap was provided, Must NOT be present otherwise. (Since 4.2)

compress: boolean (optional)

true to compress data, if the target format supports it. (default: false) (since 2.8)

on-source-error: BlockdevOnError (optional)

the action to take on an error on the source, default ‘report’. ‘stop’ and ‘enospc’ can only be used if the block device supports io-status (see BlockInfo).

on-target-error: BlockdevOnError (optional)

the action to take on an error on the target, default ‘report’ (no limitations, since this applies to a different block device than device).

auto-finalize: boolean (optional)

When false, this job will wait in a PENDING state after it has finished its work, waiting for block-job-finalize before making any block graph changes. When true, this job will automatically perform its abort or commit actions. Defaults to true. (Since 2.12)

auto-dismiss: boolean (optional)

When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and awaits block-job-dismiss. When true, this job will automatically disappear from the query list without user intervention. Defaults to true. (Since 2.12)

filter-node-name: string (optional)

the node name that should be assigned to the filter driver that the backup job inserts into the graph above node specified by drive. If this option is not given, a node name is autogenerated. (Since: 4.2)

discard-source: boolean (optional)

Discard blocks on source which have already been copied to the target. (Since 9.1)

x-perf: BackupPerf (optional)

Performance options. (Since 6.0)

Features

unstable

Member x-perf is experimental.

Note

on-source-error and on-target-error only affect background I/O. If an error occurs during a guest write request, the device’s rerror/werror actions will be used.

Since

4.2

DriveBackup (Object)

Members

target: string

the target of the new image. If the file exists, or if it is a device, the existing file/device will be used as the new destination. If it does not exist, a new file will be created.

format: string (optional)

the format of the new destination, default is to probe if mode is ‘existing’, else the format of the source

mode: NewImageMode (optional)

whether and how QEMU should create a new image, default is ‘absolute-paths’.

The members of BackupCommon

Since

1.6

BlockdevBackup (Object)

Members

target: string

the device name or node-name of the backup target node.

The members of BackupCommon

Since

2.3

blockdev-snapshot-sync (Command)

Takes a synchronous snapshot of a block device.

Arguments

The members of BlockdevSnapshotSync

Errors

• If device is not a valid block device, DeviceNotFound

Since

0.14

Example:

-> { "execute": "blockdev-snapshot-sync",
     "arguments": { "device": "ide-hd0",
                    "snapshot-file":
                    "/some/place/my-image",
                    "format": "qcow2" } }
<- { "return": {} }

blockdev-snapshot (Command)

Takes a snapshot of a block device.

Take a snapshot, by installing ‘node’ as the backing image of ‘overlay’. Additionally, if ‘node’ is associated with a block device, the block device changes to using ‘overlay’ as its new active image.

Arguments

The members of BlockdevSnapshot

Features

allow-write-only-overlay

If present, the check whether this operation is safe was relaxed so that it can be used to change backing file of a destination of a blockdev-mirror. (since 5.0)

Since

2.5

Example:

-> { "execute": "blockdev-add",
     "arguments": { "driver": "qcow2",
                    "node-name": "node1534",
                    "file": { "driver": "file",
                              "filename": "hd1.qcow2" },
                    "backing": null } }

<- { "return": {} }

-> { "execute": "blockdev-snapshot",
     "arguments": { "node": "ide-hd0",
                    "overlay": "node1534" } }
<- { "return": {} }

change-backing-file (Command)

Change the backing file in the image file metadata. This does not cause QEMU to reopen the image file to reparse the backing filename (it may, however, perform a reopen to change permissions from r/o -> r/w -> r/o, if needed). The new backing file string is written into the image file metadata, and the QEMU internal strings are updated.

Arguments

image-node-name: string

The name of the block driver state node of the image to modify. The “device” argument is used to verify “image-node-name” is in the chain described by “device”.

device: string

The device name or node-name of the root node that owns image-node-name.

backing-file: string

The string to write as the backing file. This string is not validated, so care should be taken when specifying the string or the image chain may not be able to be reopened again.

Errors

• If “device” does not exist or cannot be determined, DeviceNotFound

Since

2.1

block-commit (Command)

Live commit of data from overlay image nodes into backing nodes - i.e., writes data between ‘top’ and ‘base’ into ‘base’.

If top == base, that is an error. If top has no overlays on top of it, or if it is in use by a writer, the job will not be completed by itself. The user needs to complete the job with the block-job-complete command after getting the ready event. (Since 2.0)

If the base image is smaller than top, then the base image will be resized to be the same size as top. If top is smaller than the base image, the base will not be truncated. If you want the base image size to match the size of the smaller top, you can safely truncate it yourself once the commit operation successfully completes.

Arguments

job-id: string (optional)

identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)

device: string

the device name or node-name of a root node

base-node: string (optional)

The node name of the backing image to write data into. If not specified, this is the deepest backing image. (since: 3.1)

base: string (optional)

Same as base-node, except that it is a file name rather than a node name. This must be the exact filename string that was used to open the node; other strings, even if addressing the same file, are not accepted

top-node: string (optional)

The node name of the backing image within the image chain which contains the topmost data to be committed down. If not specified, this is the active layer. (since: 3.1)

top: string (optional)

Same as top-node, except that it is a file name rather than a node name. This must be the exact filename string that was used to open the node; other strings, even if addressing the same file, are not accepted

backing-file: string (optional)

The backing file string to write into the overlay image of ‘top’. If ‘top’ does not have an overlay image, or if ‘top’ is in use by a writer, specifying a backing file string is an error.

This filename is not validated. If a pathname string is such that it cannot be resolved by QEMU, that means that subsequent QMP or HMP commands must use node-names for the image in question, as filename lookup methods will fail.

If not specified, QEMU will automatically determine the backing file string to use, or error out if there is no obvious choice. Care should be taken when specifying the string, to specify a valid filename or protocol. (Since 2.1)

backing-mask-protocol: boolean (optional)

If true, replace any protocol mentioned in the ‘backing file format’ with ‘raw’, rather than storing the protocol name as the backing format. Can be used even when no image header will be updated (default false; since 9.0).

speed: int (optional)

the maximum speed, in bytes per second

on-error: BlockdevOnError (optional)

the action to take on an error. ‘ignore’ means that the request should be retried. (default: report; Since: 5.0)

filter-node-name: string (optional)

the node name that should be assigned to the filter driver that the commit job inserts into the graph above top. If this option is not given, a node name is autogenerated. (Since: 2.9)

auto-finalize: boolean (optional)

When false, this job will wait in a PENDING state after it has finished its work, waiting for block-job-finalize before making any block graph changes. When true, this job will automatically perform its abort or commit actions. Defaults to true. (Since 3.1)

auto-dismiss: boolean (optional)

When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and awaits block-job-dismiss. When true, this job will automatically disappear from the query list without user intervention. Defaults to true. (Since 3.1)

Features

deprecated

Members base and top are deprecated. Use base-node and top-node instead.

Errors

• If device does not exist, DeviceNotFound

Since

1.3

Example:

-> { "execute": "block-commit",
     "arguments": { "device": "virtio0",
                    "top": "/tmp/snap1.qcow2" } }
<- { "return": {} }

drive-backup (Command)

Start a point-in-time copy of a block device to a new destination. The status of ongoing drive-backup operations can be checked with query-block-jobs where the BlockJobInfo.type field has the value ‘backup’. The operation can be stopped before it has completed using the block-job-cancel command.

Arguments

The members of DriveBackup

Features

deprecated

This command is deprecated. Use blockdev-backup instead.

Errors

• If device is not a valid block device, GenericError

Since

1.6

Example:

-> { "execute": "drive-backup",
     "arguments": { "device": "drive0",
                    "sync": "full",
                    "target": "backup.img" } }
<- { "return": {} }

blockdev-backup (Command)

Start a point-in-time copy of a block device to a new destination. The status of ongoing blockdev-backup operations can be checked with query-block-jobs where the BlockJobInfo.type field has the value ‘backup’. The operation can be stopped before it has completed using the block-job-cancel command.

Arguments

The members of BlockdevBackup

Errors

• If device is not a valid block device, DeviceNotFound

Since

2.3

Example:

-> { "execute": "blockdev-backup",
     "arguments": { "device": "src-id",
                    "sync": "full",
                    "target": "tgt-id" } }
<- { "return": {} }

query-named-block-nodes (Command)

Get the named block driver list

Arguments

flat: boolean (optional)

Omit the nested data about backing image (“backing-image” key) if true. Default is false (Since 5.0)

Returns

the list of BlockDeviceInfo

Since

2.0

Example:

-> { "execute": "query-named-block-nodes" }
<- { "return": [ { "ro":false,
                   "drv":"qcow2",
                   "encrypted":false,
                   "file":"disks/test.qcow2",
                   "node-name": "my-node",
                   "backing_file_depth":1,
                   "detect_zeroes":"off",
                   "bps":1000000,
                   "bps_rd":0,
                   "bps_wr":0,
                   "iops":1000000,
                   "iops_rd":0,
                   "iops_wr":0,
                   "bps_max": 8000000,
                   "bps_rd_max": 0,
                   "bps_wr_max": 0,
                   "iops_max": 0,
                   "iops_rd_max": 0,
                   "iops_wr_max": 0,
                   "iops_size": 0,
                   "write_threshold": 0,
                   "image":{
                      "filename":"disks/test.qcow2",
                      "format":"qcow2",
                      "virtual-size":2048000,
                      "backing_file":"base.qcow2",
                      "full-backing-filename":"disks/base.qcow2",
                      "backing-filename-format":"qcow2",
                      "snapshots":[
                         {
                            "id": "1",
                            "name": "snapshot1",
                            "vm-state-size": 0,
                            "date-sec": 10000200,
                            "date-nsec": 12,
                            "vm-clock-sec": 206,
                            "vm-clock-nsec": 30
                         }
                      ],
                      "backing-image":{
                          "filename":"disks/base.qcow2",
                          "format":"qcow2",
                          "virtual-size":2048000
                      }
                   } } ] }

XDbgBlockGraphNodeType (Enum)

Values

block-backend

corresponds to BlockBackend

block-job

corresponds to BlockJob

block-driver

corresponds to BlockDriverState

Since

4.0

XDbgBlockGraphNode (Object)

Members

id: int

Block graph node identifier. This id is generated only for x-debug-query-block-graph and does not relate to any other identifiers in Qemu.

type: XDbgBlockGraphNodeType

Type of graph node. Can be one of block-backend, block-job or block-driver-state.

name: string

Human readable name of the node. Corresponds to node-name for block-driver-state nodes; is not guaranteed to be unique in the whole graph (with block-jobs and block-backends).

Since

4.0

BlockPermission (Enum)

Enum of base block permissions.

Values

consistent-read

A user that has the “permission” of consistent reads is guaranteed that their view of the contents of the block device is complete and self-consistent, representing the contents of a disk at a specific point. For most block devices (including their backing files) this is true, but the property cannot be maintained in a few situations like for intermediate nodes of a commit block job.

write

This permission is required to change the visible disk contents.

write-unchanged

This permission (which is weaker than BLK_PERM_WRITE) is both enough and required for writes to the block node when the caller promises that the visible disk content doesn’t change. As the BLK_PERM_WRITE permission is strictly stronger, either is sufficient to perform an unchanging write.

resize

This permission is required to change the size of a block node.

Since

4.0

XDbgBlockGraphEdge (Object)

Block Graph edge description for x-debug-query-block-graph.

Members

parent: int

parent id

child: int

child id

name: string

name of the relation (examples are ‘file’ and ‘backing’)

perm: array of BlockPermission

granted permissions for the parent operating on the child

shared-perm: array of BlockPermission

permissions that can still be granted to other users of the child while it is still attached to this parent

Since

4.0

XDbgBlockGraph (Object)

Block Graph - list of nodes and list of edges.

Members

nodes: array of XDbgBlockGraphNode

Not documented

edges: array of XDbgBlockGraphEdge

Not documented

Since

4.0

x-debug-query-block-graph (Command)

Get the block graph.

Features

unstable

This command is meant for debugging.

Since

4.0

drive-mirror (Command)

Start mirroring a block device’s writes to a new destination. target specifies the target of the new image. If the file exists, or if it is a device, it will be used as the new destination for writes. If it does not exist, a new file will be created. format specifies the format of the mirror image, default is to probe if mode=’existing’, else the format of the source.

Arguments

The members of DriveMirror

Errors

• If device is not a valid block device, GenericError

Since

1.3

Example:

-> { "execute": "drive-mirror",
     "arguments": { "device": "ide-hd0",
                    "target": "/some/place/my-image",
                    "sync": "full",
                    "format": "qcow2" } }
<- { "return": {} }

DriveMirror (Object)

A set of parameters describing drive mirror setup.

Members

job-id: string (optional)

identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)

device: string

the device name or node-name of a root node whose writes should be mirrored.

target: string

the target of the new image. If the file exists, or if it is a device, the existing file/device will be used as the new destination. If it does not exist, a new file will be created.

format: string (optional)

the format of the new destination, default is to probe if mode is ‘existing’, else the format of the source

node-name: string (optional)

the new block driver state node name in the graph (Since 2.1)

replaces: string (optional)

with sync=full graph node name to be replaced by the new image when a whole image copy is done. This can be used to repair broken Quorum files. By default, device is replaced, although implicitly created filters on it are kept. (Since 2.1)

mode: NewImageMode (optional)

whether and how QEMU should create a new image, default is ‘absolute-paths’.

speed: int (optional)

the maximum speed, in bytes per second

sync: MirrorSyncMode

what parts of the disk image should be copied to the destination (all the disk, only the sectors allocated in the topmost image, or only new I/O).

granularity: int (optional)

granularity of the dirty bitmap, default is 64K if the image format doesn’t have clusters, 4K if the clusters are smaller than that, else the cluster size. Must be a power of 2 between 512 and 64M (since 1.4).

buf-size: int (optional)

maximum amount of data in flight from source to target (since 1.4).

on-source-error: BlockdevOnError (optional)

the action to take on an error on the source, default ‘report’. ‘stop’ and ‘enospc’ can only be used if the block device supports io-status (see BlockInfo).

on-target-error: BlockdevOnError (optional)

the action to take on an error on the target, default ‘report’ (no limitations, since this applies to a different block device than device).

unmap: boolean (optional)

Whether to try to unmap target sectors where source has only zero. If true, and target unallocated sectors will read as zero, target image sectors will be unmapped; otherwise, zeroes will be written. Both will result in identical contents. Default is true. (Since 2.4)

copy-mode: MirrorCopyMode (optional)

when to copy data to the destination; defaults to ‘background’ (Since: 3.0)

auto-finalize: boolean (optional)

When false, this job will wait in a PENDING state after it has finished its work, waiting for block-job-finalize before making any block graph changes. When true, this job will automatically perform its abort or commit actions. Defaults to true. (Since 3.1)

auto-dismiss: boolean (optional)

When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and awaits block-job-dismiss. When true, this job will automatically disappear from the query list without user intervention. Defaults to true. (Since 3.1)

Since

1.3

BlockDirtyBitmap (Object)

Members

node: string

name of device/node which the bitmap is tracking

name: string

name of the dirty bitmap

Since

2.4

BlockDirtyBitmapAdd (Object)

Members

node: string

name of device/node which the bitmap is tracking

name: string

name of the dirty bitmap (must be less than 1024 bytes)

granularity: int (optional)

the bitmap granularity, default is 64k for block-dirty-bitmap-add

persistent: boolean (optional)

the bitmap is persistent, i.e. it will be saved to the corresponding block device image file on its close. For now only Qcow2 disks support persistent bitmaps. Default is false for block-dirty-bitmap-add. (Since: 2.10)

disabled: boolean (optional)

the bitmap is created in the disabled state, which means that it will not track drive changes. The bitmap may be enabled with block-dirty-bitmap-enable. Default is false. (Since: 4.0)

Since

2.4

BlockDirtyBitmapOrStr (Alternate)

Members

local: string

name of the bitmap, attached to the same node as target bitmap.

external: BlockDirtyBitmap

bitmap with specified node

Since

4.1

BlockDirtyBitmapMerge (Object)

Members

node: string

name of device/node which the target bitmap is tracking

target: string

name of the destination dirty bitmap

bitmaps: array of BlockDirtyBitmapOrStr

name(s) of the source dirty bitmap(s) at node and/or fully specified BlockDirtyBitmap elements. The latter are supported since 4.1.

Since

4.0

block-dirty-bitmap-add (Command)

Create a dirty bitmap with a name on the node, and start tracking the writes.

Arguments

The members of BlockDirtyBitmapAdd

Errors

• If node is not a valid block device or node, DeviceNotFound

• If name is already taken, GenericError

Since

2.4

Example:

-> { "execute": "block-dirty-bitmap-add",
     "arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }

block-dirty-bitmap-remove (Command)

Stop write tracking and remove the dirty bitmap that was created with block-dirty-bitmap-add. If the bitmap is persistent, remove it from its storage too.

Arguments

The members of BlockDirtyBitmap

Errors

• If node is not a valid block device or node, DeviceNotFound

• If name is not found, GenericError

• if name is frozen by an operation, GenericError

Since

2.4

Example:

-> { "execute": "block-dirty-bitmap-remove",
     "arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }

block-dirty-bitmap-clear (Command)

Clear (reset) a dirty bitmap on the device, so that an incremental backup from this point in time forward will only backup clusters modified after this clear operation.

Arguments

The members of BlockDirtyBitmap

Errors

• If node is not a valid block device, DeviceNotFound

• If name is not found, GenericError

Since

2.4

Example:

-> { "execute": "block-dirty-bitmap-clear",
     "arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }

block-dirty-bitmap-enable (Command)

Enables a dirty bitmap so that it will begin tracking disk changes.

Arguments

The members of BlockDirtyBitmap

Errors

• If node is not a valid block device, DeviceNotFound

• If name is not found, GenericError

Since

4.0

Example:

-> { "execute": "block-dirty-bitmap-enable",
     "arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }

block-dirty-bitmap-disable (Command)

Disables a dirty bitmap so that it will stop tracking disk changes.

Arguments

The members of BlockDirtyBitmap

Errors

• If node is not a valid block device, DeviceNotFound

• If name is not found, GenericError

Since

4.0

Example:

-> { "execute": "block-dirty-bitmap-disable",
     "arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }

block-dirty-bitmap-merge (Command)

Merge dirty bitmaps listed in bitmaps to the target dirty bitmap. Dirty bitmaps in bitmaps will be unchanged, except if it also appears as the target bitmap. Any bits already set in target will still be set after the merge, i.e., this operation does not clear the target. On error, target is unchanged.

The resulting bitmap will count as dirty any clusters that were dirty in any of the source bitmaps. This can be used to achieve backup checkpoints, or in simpler usages, to copy bitmaps.

Arguments

The members of BlockDirtyBitmapMerge

Errors

• If node is not a valid block device, DeviceNotFound

• If any bitmap in bitmaps or target is not found, GenericError

• If any of the bitmaps have different sizes or granularities, GenericError

Since

4.0

Example:

-> { "execute": "block-dirty-bitmap-merge",
     "arguments": { "node": "drive0", "target": "bitmap0",
                    "bitmaps": ["bitmap1"] } }
<- { "return": {} }

BlockDirtyBitmapSha256 (Object)

SHA256 hash of dirty bitmap data

Members

sha256: string

ASCII representation of SHA256 bitmap hash

Since

2.10

x-debug-block-dirty-bitmap-sha256 (Command)

Get bitmap SHA256.

Arguments

The members of BlockDirtyBitmap

Features

unstable

This command is meant for debugging.

Returns

BlockDirtyBitmapSha256

Errors

• If node is not a valid block device, DeviceNotFound

• If name is not found or if hashing has failed, GenericError

Since

2.10

blockdev-mirror (Command)

Start mirroring a block device’s writes to a new destination.

Arguments

job-id: string (optional)

identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)

device: string

The device name or node-name of a root node whose writes should be mirrored.

target: string

the id or node-name of the block device to mirror to. This mustn’t be attached to guest.

replaces: string (optional)

with sync=full graph node name to be replaced by the new image when a whole image copy is done. This can be used to repair broken Quorum files. By default, device is replaced, although implicitly created filters on it are kept.

speed: int (optional)

the maximum speed, in bytes per second

sync: MirrorSyncMode

what parts of the disk image should be copied to the destination (all the disk, only the sectors allocated in the topmost image, or only new I/O).

granularity: int (optional)

granularity of the dirty bitmap, default is 64K if the image format doesn’t have clusters, 4K if the clusters are smaller than that, else the cluster size. Must be a power of 2 between 512 and 64M

buf-size: int (optional)

maximum amount of data in flight from source to target

on-source-error: BlockdevOnError (optional)

the action to take on an error on the source, default ‘report’. ‘stop’ and ‘enospc’ can only be used if the block device supports io-status (see BlockInfo).

on-target-error: BlockdevOnError (optional)

the action to take on an error on the target, default ‘report’ (no limitations, since this applies to a different block device than device).

filter-node-name: string (optional)

the node name that should be assigned to the filter driver that the mirror job inserts into the graph above device. If this option is not given, a node name is autogenerated. (Since: 2.9)

copy-mode: MirrorCopyMode (optional)

when to copy data to the destination; defaults to ‘background’ (Since: 3.0)

auto-finalize: boolean (optional)

When false, this job will wait in a PENDING state after it has finished its work, waiting for block-job-finalize before making any block graph changes. When true, this job will automatically perform its abort or commit actions. Defaults to true. (Since 3.1)

auto-dismiss: boolean (optional)

When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and awaits block-job-dismiss. When true, this job will automatically disappear from the query list without user intervention. Defaults to true. (Since 3.1)

Since

2.6

Example:

-> { "execute": "blockdev-mirror",
     "arguments": { "device": "ide-hd0",
                    "target": "target0",
                    "sync": "full" } }
<- { "return": {} }

BlockIOThrottle (Object)

A set of parameters describing block throttling.

Members

device: string (optional)

Block device name

id: string (optional)

The name or QOM path of the guest device (since: 2.8)

bps: int

total throughput limit in bytes per second

bps_rd: int

read throughput limit in bytes per second

bps_wr: int

write throughput limit in bytes per second

iops: int

total I/O operations per second

iops_rd: int

read I/O operations per second

iops_wr: int

write I/O operations per second

bps_max: int (optional)

total throughput limit during bursts, in bytes (Since 1.7)

bps_rd_max: int (optional)

read throughput limit during bursts, in bytes (Since 1.7)

bps_wr_max: int (optional)

write throughput limit during bursts, in bytes (Since 1.7)

iops_max: int (optional)

total I/O operations per second during bursts, in bytes (Since 1.7)

iops_rd_max: int (optional)

read I/O operations per second during bursts, in bytes (Since 1.7)

iops_wr_max: int (optional)

write I/O operations per second during bursts, in bytes (Since 1.7)

bps_max_length: int (optional)

maximum length of the bps_max burst period, in seconds. It must only be set if bps_max is set as well. Defaults to 1. (Since 2.6)

bps_rd_max_length: int (optional)

maximum length of the bps_rd_max burst period, in seconds. It must only be set if bps_rd_max is set as well. Defaults to 1. (Since 2.6)

bps_wr_max_length: int (optional)

maximum length of the bps_wr_max burst period, in seconds. It must only be set if bps_wr_max is set as well. Defaults to 1. (Since 2.6)

iops_max_length: int (optional)

maximum length of the iops burst period, in seconds. It must only be set if iops_max is set as well. Defaults to 1. (Since 2.6)

iops_rd_max_length: int (optional)

maximum length of the iops_rd_max burst period, in seconds. It must only be set if iops_rd_max is set as well. Defaults to 1. (Since 2.6)

iops_wr_max_length: int (optional)

maximum length of the iops_wr_max burst period, in seconds. It must only be set if iops_wr_max is set as well. Defaults to 1. (Since 2.6)

iops_size: int (optional)

an I/O size in bytes (Since 1.7)

group: string (optional)

throttle group name (Since 2.4)

Features

deprecated

Member device is deprecated. Use id instead.

Since

1.1

ThrottleLimits (Object)

Limit parameters for throttling. Since some limit combinations are illegal, limits should always be set in one transaction. All fields are optional. When setting limits, if a field is missing the current value is not changed.

Members

iops-total: int (optional)

limit total I/O operations per second

iops-total-max: int (optional)

I/O operations burst

iops-total-max-length: int (optional)

length of the iops-total-max burst period, in seconds It must only be set if iops-total-max is set as well.

iops-read: int (optional)

limit read operations per second

iops-read-max: int (optional)

I/O operations read burst

iops-read-max-length: int (optional)

length of the iops-read-max burst period, in seconds It must only be set if iops-read-max is set as well.

iops-write: int (optional)

limit write operations per second

iops-write-max: int (optional)

I/O operations write burst

iops-write-max-length: int (optional)

length of the iops-write-max burst period, in seconds It must only be set if iops-write-max is set as well.

bps-total: int (optional)

limit total bytes per second

bps-total-max: int (optional)

total bytes burst

bps-total-max-length: int (optional)

length of the bps-total-max burst period, in seconds. It must only be set if bps-total-max is set as well.

bps-read: int (optional)

limit read bytes per second

bps-read-max: int (optional)

total bytes read burst

bps-read-max-length: int (optional)

length of the bps-read-max burst period, in seconds It must only be set if bps-read-max is set as well.

bps-write: int (optional)

limit write bytes per second

bps-write-max: int (optional)

total bytes write burst

bps-write-max-length: int (optional)

length of the bps-write-max burst period, in seconds It must only be set if bps-write-max is set as well.

iops-size: int (optional)

when limiting by iops max size of an I/O in bytes

Since

2.11

ThrottleGroupProperties (Object)

Properties for throttle-group objects.

Members

limits: ThrottleLimits (optional)

limits to apply for this throttle group

x-iops-total: int (optional)

Not documented

x-iops-total-max: int (optional)

Not documented

x-iops-total-max-length: int (optional)

Not documented

x-iops-read: int (optional)

Not documented

x-iops-read-max: int (optional)

Not documented

x-iops-read-max-length: int (optional)

Not documented

x-iops-write: int (optional)

Not documented

x-iops-write-max: int (optional)

Not documented

x-iops-write-max-length: int (optional)

Not documented

x-bps-total: int (optional)

Not documented

x-bps-total-max: int (optional)

Not documented

x-bps-total-max-length: int (optional)

Not documented

x-bps-read: int (optional)

Not documented

x-bps-read-max: int (optional)

Not documented

x-bps-read-max-length: int (optional)

Not documented

x-bps-write: int (optional)

Not documented

x-bps-write-max: int (optional)

Not documented

x-bps-write-max-length: int (optional)

Not documented

x-iops-size: int (optional)

Not documented

Features

unstable

All members starting with x- are aliases for the same key without x- in the limits object. This is not a stable interface and may be removed or changed incompatibly in the future. Use limits for a supported stable interface.

Since

2.11

block-stream (Command)

Copy data from a backing file into a block device.

The block streaming operation is performed in the background until the entire backing file has been copied. This command returns immediately once streaming has started. The status of ongoing block streaming operations can be checked with query-block-jobs. The operation can be stopped before it has completed using the block-job-cancel command.

The node that receives the data is called the top image, can be located in any part of the chain (but always above the base image; see below) and can be specified using its device or node name. Earlier qemu versions only allowed ‘device’ to name the top level node; presence of the ‘base-node’ parameter during introspection can be used as a witness of the enhanced semantics of ‘device’.

If a base file is specified then sectors are not copied from that base file and its backing chain. This can be used to stream a subset of the backing file chain instead of flattening the entire image. When streaming completes the image file will have the base file as its backing file, unless that node was changed while the job was running. In that case, base’s parent’s backing (or filtered, whichever exists) child (i.e., base at the beginning of the job) will be the new backing file.

On successful completion the image file is updated to drop the backing file and the BLOCK_JOB_COMPLETED event is emitted.

In case device is a filter node, block-stream modifies the first non-filter overlay node below it to point to the new backing node instead of modifying device itself.

Arguments

job-id: string (optional)

identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)

device: string

the device or node name of the top image

base: string (optional)

the common backing file name. It cannot be set if base-node or bottom is also set.

base-node: string (optional)

the node name of the backing file. It cannot be set if base or bottom is also set. (Since 2.8)

bottom: string (optional)

the last node in the chain that should be streamed into top. It cannot be set if base or base-node is also set. It cannot be filter node. (Since 6.0)

backing-file: string (optional)

The backing file string to write into the top image. This filename is not validated.

If a pathname string is such that it cannot be resolved by QEMU, that means that subsequent QMP or HMP commands must use node-names for the image in question, as filename lookup methods will fail.

If not specified, QEMU will automatically determine the backing file string to use, or error out if there is no obvious choice. Care should be taken when specifying the string, to specify a valid filename or protocol. (Since 2.1)

backing-mask-protocol: boolean (optional)

If true, replace any protocol mentioned in the ‘backing file format’ with ‘raw’, rather than storing the protocol name as the backing format. Can be used even when no image header will be updated (default false; since 9.0).

speed: int (optional)

the maximum speed, in bytes per second

on-error: BlockdevOnError (optional)

the action to take on an error (default report). ‘stop’ and ‘enospc’ can only be used if the block device supports io-status (see BlockInfo). (Since 1.3)

filter-node-name: string (optional)

the node name that should be assigned to the filter driver that the stream job inserts into the graph above device. If this option is not given, a node name is autogenerated. (Since: 6.0)

auto-finalize: boolean (optional)

When false, this job will wait in a PENDING state after it has finished its work, waiting for block-job-finalize before making any block graph changes. When true, this job will automatically perform its abort or commit actions. Defaults to true. (Since 3.1)

auto-dismiss: boolean (optional)

When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and awaits block-job-dismiss. When true, this job will automatically disappear from the query list without user intervention. Defaults to true. (Since 3.1)

Errors

• If device does not exist, DeviceNotFound.

Since

1.1

Example:

-> { "execute": "block-stream",
     "arguments": { "device": "virtio0",
                    "base": "/tmp/master.qcow2" } }
<- { "return": {} }

block-job-set-speed (Command)

Set maximum speed for a background block operation.

This command can only be issued when there is an active block job.

Throttling can be disabled by setting the speed to 0.

Arguments

device: string

The job identifier. This used to be a device name (hence the name of the parameter), but since QEMU 2.7 it can have other values.

speed: int

the maximum speed, in bytes per second, or 0 for unlimited. Defaults to 0.

Errors

• If no background operation is active on this device, DeviceNotActive

Since

1.1

block-job-cancel (Command)

Stop an active background block operation.

This command returns immediately after marking the active background block operation for cancellation. It is an error to call this command if no operation is in progress.

The operation will cancel as soon as possible and then emit the BLOCK_JOB_CANCELLED event. Before that happens the job is still visible when enumerated using query-block-jobs.

Note that if you issue ‘block-job-cancel’ after ‘drive-mirror’ has indicated (via the event BLOCK_JOB_READY) that the source and destination are synchronized, then the event triggered by this command changes to BLOCK_JOB_COMPLETED, to indicate that the mirroring has ended and the destination now has a point-in-time copy tied to the time of the cancellation.

For streaming, the image file retains its backing file unless the streaming operation happens to complete just as it is being cancelled. A new streaming operation can be started at a later time to finish copying all data from the backing file.

Arguments

device: string

The job identifier. This used to be a device name (hence the name of the parameter), but since QEMU 2.7 it can have other values.

force: boolean (optional)

If true, and the job has already emitted the event BLOCK_JOB_READY, abandon the job immediately (even if it is paused) instead of waiting for the destination to complete its final synchronization (since 1.3)

Errors

• If no background operation is active on this device, DeviceNotActive

Since

1.1

block-job-pause (Command)

Pause an active background block operation.

This command returns immediately after marking the active background block operation for pausing. It is an error to call this command if no operation is in progress or if the job is already paused.

The operation will pause as soon as possible. No event is emitted when the operation is actually paused. Cancelling a paused job automatically resumes it.

Arguments

device: string

The job identifier. This used to be a device name (hence the name of the parameter), but since QEMU 2.7 it can have other values.

Errors

• If no background operation is active on this device, DeviceNotActive

Since

1.3

block-job-resume (Command)

Resume an active background block operation.

This command returns immediately after resuming a paused background block operation. It is an error to call this command if no operation is in progress or if the job is not paused.

This command also clears the error status of the job.

Arguments

device: string

The job identifier. This used to be a device name (hence the name of the parameter), but since QEMU 2.7 it can have other values.

Errors

• If no background operation is active on this device, DeviceNotActive

Since

1.3

block-job-complete (Command)

Manually trigger completion of an active background block operation. This is supported for drive mirroring, where it also switches the device to write to the target path only. The ability to complete is signaled with a BLOCK_JOB_READY event.

This command completes an active background block operation synchronously. The ordering of this command’s return with the BLOCK_JOB_COMPLETED event is not defined. Note that if an I/O error occurs during the processing of this command: 1) the command itself will fail; 2) the error will be processed according to the rerror/werror arguments that were specified when starting the operation.

A cancelled or paused job cannot be completed.

Arguments

device: string

The job identifier. This used to be a device name (hence the name of the parameter), but since QEMU 2.7 it can have other values.

Errors

• If no background operation is active on this device, DeviceNotActive

Since

1.3

block-job-dismiss (Command)

For jobs that have already concluded, remove them from the block-job-query list. This command only needs to be run for jobs which were started with QEMU 2.12+ job lifetime management semantics.

This command will refuse to operate on any job that has not yet reached its terminal state, JOB_STATUS_CONCLUDED. For jobs that make use of the BLOCK_JOB_READY event, block-job-cancel or block-job-complete will still need to be used as appropriate.

Arguments

id: string

The job identifier.

Since

2.12

block-job-finalize (Command)

Once a job that has manual=true reaches the pending state, it can be instructed to finalize any graph changes and do any necessary cleanup via this command. For jobs in a transaction, instructing one job to finalize will force ALL jobs in the transaction to finalize, so it is only necessary to instruct a single member job to finalize.

Arguments

id: string

The job identifier.

Since

2.12

BlockJobChangeOptionsMirror (Object)

Members

copy-mode: MirrorCopyMode

Switch to this copy mode. Currently, only the switch from ‘background’ to ‘write-blocking’ is implemented.

Since

8.2

BlockJobChangeOptions (Object)

Block job options that can be changed after job creation.

Members

id: string

The job identifier

type: JobType

The job type

The members of BlockJobChangeOptionsMirror when type is "mirror"

Since

8.2

block-job-change (Command)

Change the block job’s options.

Arguments

The members of BlockJobChangeOptions

Since

8.2

BlockdevDiscardOptions (Enum)

Determines how to handle discard requests.

Values

ignore

Ignore the request

unmap

Forward as an unmap request

Since

2.9

BlockdevDetectZeroesOptions (Enum)

Describes the operation mode for the automatic conversion of plain zero writes by the OS to driver specific optimized zero write commands.

Values

off

Disabled (default)

on

Enabled

unmap

Enabled and even try to unmap blocks if possible. This requires also that BlockdevDiscardOptions is set to unmap for this device.

Since

2.1

BlockdevAioOptions (Enum)

Selects the AIO backend to handle I/O requests

Values

threads

Use qemu’s thread pool

native

Use native AIO backend (only Linux and Windows)

io_uring (If: CONFIG_LINUX_IO_URING)

Use linux io_uring (since 5.0)

Since

2.9

BlockdevCacheOptions (Object)

Includes cache-related options for block devices

Members

direct: boolean (optional)

enables use of O_DIRECT (bypass the host page cache; default: false)

no-flush: boolean (optional)

ignore any flush requests for the device (default: false)

Since

2.9

BlockdevDriver (Enum)

Drivers that are supported in block device operations.

Values

throttle

Since 2.11

nvme

Since 2.12

copy-on-read

Since 3.0

blklogwrites

Since 3.0

blkreplay

Since 4.2

compress

Since 5.0

copy-before-write

Since 6.2

snapshot-access

Since 7.0

blkdebug

Not documented

blkverify

Not documented

bochs

Not documented

cloop

Not documented

dmg

Not documented

file

Not documented

ftp

Not documented

ftps

Not documented

gluster

Not documented

host_cdrom (If: HAVE_HOST_BLOCK_DEVICE)

Not documented

host_device (If: HAVE_HOST_BLOCK_DEVICE)

Not documented

http

Not documented

https

Not documented

io_uring (If: CONFIG_BLKIO)

Not documented

iscsi

Not documented

luks

Not documented

nbd

Not documented

nfs

Not documented

null-aio

Not documented

null-co

Not documented

nvme-io_uring (If: CONFIG_BLKIO)

Not documented

parallels

Not documented

preallocate

Not documented

qcow

Not documented

qcow2

Not documented

qed

Not documented

quorum

Not documented

raw

Not documented

rbd

Not documented

replication (If: CONFIG_REPLICATION)

Not documented

ssh

Not documented

vdi

Not documented

vhdx

Not documented

virtio-blk-vfio-pci (If: CONFIG_BLKIO)

Not documented

virtio-blk-vhost-user (If: CONFIG_BLKIO)

Not documented

virtio-blk-vhost-vdpa (If: CONFIG_BLKIO)

Not documented

vmdk

Not documented

vpc

Not documented

vvfat

Not documented

Features

deprecated

Member gluster is deprecated because GlusterFS development ceased.

Since

2.9

BlockdevOptionsFile (Object)

Driver specific block device options for the file backend.

Members

filename: string

path to the image file

pr-manager: string (optional)

the id for the object that will handle persistent reservations for this device (default: none, forward the commands via SG_IO; since 2.11)

aio: BlockdevAioOptions (optional)

AIO backend (default: threads) (since: 2.8)

aio-max-batch: int (optional)

maximum number of requests to batch together into a single submission in the AIO backend. The smallest value between this and the aio-max-batch value of the IOThread object is chosen. 0 means that the AIO backend will handle it automatically. (default: 0, since 6.2)

locking: OnOffAuto (optional)

whether to enable file locking. If set to ‘auto’, only enable when Open File Descriptor (OFD) locking API is available (default: auto, since 2.10)

drop-cache: boolean (optional) (If: CONFIG_LINUX)

invalidate page cache during live migration. This prevents stale data on the migration destination with cache.direct=off. Currently only supported on Linux hosts. (default: on, since: 4.0)

x-check-cache-dropped: boolean (optional)

whether to check that page cache was dropped on live migration. May cause noticeable delays if the image file is large, do not use in production. (default: off) (since: 3.0)

Features

dynamic-auto-read-only

If present, enabled auto-read-only means that the driver will open the image read-only at first, dynamically reopen the image file read-write when the first writer is attached to the node and reopen read-only when the last writer is detached. This allows giving QEMU write permissions only on demand when an operation actually needs write access.

unstable

Member x-check-cache-dropped is meant for debugging.

Since

2.9

BlockdevOptionsNull (Object)

Driver specific block device options for the null backend.

Members

size: int (optional)

size of the device in bytes.

latency-ns: int (optional)

emulated latency (in nanoseconds) in processing requests. Default to zero which completes requests immediately. (Since 2.4)

read-zeroes: boolean (optional)

if true, reads from the device produce zeroes; if false, the buffer is left unchanged. (default: false; since: 4.1)

Since

2.9

BlockdevOptionsNVMe (Object)

Driver specific block device options for the NVMe backend.

Members

device: string

PCI controller address of the NVMe device in format hhhh:bb:ss.f (host:bus:slot.function)

namespace: int

namespace number of the device, starting from 1.

Note that the PCI device must have been unbound from any host kernel driver before instructing QEMU to add the blockdev.

Since

2.12

BlockdevOptionsVVFAT (Object)

Driver specific block device options for the vvfat protocol.

Members

dir: string

directory to be exported as FAT image

fat-type: int (optional)

FAT type: 12, 16 or 32

floppy: boolean (optional)

whether to export a floppy image (true) or partitioned hard disk (false; default)

label: string (optional)

set the volume label, limited to 11 bytes. FAT16 and FAT32 traditionally have some restrictions on labels, which are ignored by most operating systems. Defaults to “QEMU VVFAT”. (since 2.4)

rw: boolean (optional)

whether to allow write operations (default: false)

Since

2.9

BlockdevOptionsGenericFormat (Object)

Driver specific block device options for image format that have no option besides their data source.

Members

file: BlockdevRef

reference to or definition of the data source block device

Since

2.9

BlockdevOptionsLUKS (Object)

Driver specific block device options for LUKS.

Members

key-secret: string (optional)

the ID of a QCryptoSecret object providing the decryption key (since 2.6). Mandatory except when doing a metadata-only probe of the image.

header: BlockdevRef (optional)

block device holding a detached LUKS header. (since 9.0)

The members of BlockdevOptionsGenericFormat

Since

2.9

BlockdevOptionsGenericCOWFormat (Object)

Driver specific block device options for image format that have no option besides their data source and an optional backing file.

Members

backing: BlockdevRefOrNull (optional)

reference to or definition of the backing file block device, null disables the backing file entirely. Defaults to the backing file stored the image file.

The members of BlockdevOptionsGenericFormat

Since

2.9

Qcow2OverlapCheckMode (Enum)

General overlap check modes.

Values

none

Do not perform any checks

constant

Perform only checks which can be done in constant time and without reading anything from disk

cached

Perform only checks which can be done without reading anything from disk

all

Perform all available overlap checks

Since

2.9

Qcow2OverlapCheckFlags (Object)

Structure of flags for each metadata structure. Setting a field to ‘true’ makes QEMU guard that Qcow2 format structure against unintended overwriting. See Qcow2 format specification for detailed information on these structures. The default value is chosen according to the template given.

Members

template: Qcow2OverlapCheckMode (optional)

Specifies a template mode which can be adjusted using the other flags, defaults to ‘cached’

main-header: boolean (optional)

Qcow2 format header

active-l1: boolean (optional)

Qcow2 active L1 table

active-l2: boolean (optional)

Qcow2 active L2 table

refcount-table: boolean (optional)

Qcow2 refcount table

refcount-block: boolean (optional)

Qcow2 refcount blocks

snapshot-table: boolean (optional)

Qcow2 snapshot table

inactive-l1: boolean (optional)

Qcow2 inactive L1 tables

inactive-l2: boolean (optional)

Qcow2 inactive L2 tables

bitmap-directory: boolean (optional)

Qcow2 bitmap directory (since 3.0)

Since

2.9

Qcow2OverlapChecks (Alternate)

Specifies which metadata structures should be guarded against unintended overwriting.

Members

flags: Qcow2OverlapCheckFlags

set of flags for separate specification of each metadata structure type

mode: Qcow2OverlapCheckMode

named mode which chooses a specific set of flags

Since

2.9

BlockdevQcowEncryptionFormat (Enum)

Values

aes

AES-CBC with plain64 initialization vectors

Since

2.10

BlockdevQcowEncryption (Object)

Members

format: BlockdevQcowEncryptionFormat

encryption format

The members of QCryptoBlockOptionsQCow when format is "aes"

Since

2.10

BlockdevOptionsQcow (Object)

Driver specific block device options for qcow.

Members

encrypt: BlockdevQcowEncryption (optional)

Image decryption options. Mandatory for encrypted images, except when doing a metadata-only probe of the image.

The members of BlockdevOptionsGenericCOWFormat

Since

2.10

BlockdevQcow2EncryptionFormat (Enum)

Values

aes

AES-CBC with plain64 initialization vectors

luks

Not documented

Since

2.10

BlockdevQcow2Encryption (Object)

Members

format: BlockdevQcow2EncryptionFormat

encryption format

The members of QCryptoBlockOptionsQCow when format is "aes"

The members of QCryptoBlockOptionsLUKS when format is "luks"

Since

2.10

BlockdevOptionsPreallocate (Object)

Filter driver intended to be inserted between format and protocol node and do preallocation in protocol node on write.

Members

prealloc-align: int (optional)

on preallocation, align file length to this number, default 1048576 (1M)

prealloc-size: int (optional)

how much to preallocate, default 134217728 (128M)

The members of BlockdevOptionsGenericFormat

Since

6.0

BlockdevOptionsQcow2 (Object)

Driver specific block device options for qcow2.

Members

lazy-refcounts: boolean (optional)

whether to enable the lazy refcounts feature (default is taken from the image file)

pass-discard-request: boolean (optional)

whether discard requests to the qcow2 device should be forwarded to the data source

pass-discard-snapshot: boolean (optional)

whether discard requests for the data source should be issued when a snapshot operation (e.g. deleting a snapshot) frees clusters in the qcow2 file

pass-discard-other: boolean (optional)

whether discard requests for the data source should be issued on other occasions where a cluster gets freed

discard-no-unref: boolean (optional)

when enabled, data clusters will remain preallocated when they are no longer used, e.g. because they are discarded or converted to zero clusters. As usual, whether the old data is discarded or kept on the protocol level (i.e. in the image file) depends on the setting of the pass-discard-request option. Keeping the clusters preallocated prevents qcow2 fragmentation that would otherwise be caused by freeing and re-allocating them later. Besides potential performance degradation, such fragmentation can lead to increased allocation of clusters past the end of the image file, resulting in image files whose file length can grow much larger than their guest disk size would suggest. If image file length is of concern (e.g. when storing qcow2 images directly on block devices), you should consider enabling this option. (since 8.1)

overlap-check: Qcow2OverlapChecks (optional)

which overlap checks to perform for writes to the image, defaults to ‘cached’ (since 2.2)

cache-size: int (optional)

the maximum total size of the L2 table and refcount block caches in bytes (since 2.2)

l2-cache-size: int (optional)

the maximum size of the L2 table cache in bytes (since 2.2)

l2-cache-entry-size: int (optional)

the size of each entry in the L2 cache in bytes. It must be a power of two between 512 and the cluster size. The default value is the cluster size (since 2.12)

refcount-cache-size: int (optional)

the maximum size of the refcount block cache in bytes (since 2.2)

cache-clean-interval: int (optional)

clean unused entries in the L2 and refcount caches. The interval is in seconds. The default value is 600 on supporting platforms, and 0 on other platforms. 0 disables this feature. (since 2.5)

encrypt: BlockdevQcow2Encryption (optional)

Image decryption options. Mandatory for encrypted images, except when doing a metadata-only probe of the image. (since 2.10)

data-file: BlockdevRef (optional)

reference to or definition of the external data file. This may only be specified for images that require an external data file. If it is not specified for such an image, the data file name is loaded from the image file. (since 4.0)

The members of BlockdevOptionsGenericCOWFormat

Since

2.9

SshHostKeyCheckMode (Enum)

Values

none

Don’t check the host key at all

hash

Compare the host key with a given hash

known_hosts

Check the host key against the known_hosts file

Since

2.12

SshHostKeyCheckHashType (Enum)

Values

md5

The given hash is an md5 hash

sha1

The given hash is an sha1 hash

sha256

The given hash is an sha256 hash

Since

2.12

SshHostKeyHash (Object)

Members

type: SshHostKeyCheckHashType

The hash algorithm used for the hash

hash: string

The expected hash value

Since

2.12

SshHostKeyCheck (Object)

Members

mode: SshHostKeyCheckMode

How to check the host key

The members of SshHostKeyHash when mode is "hash"

Since

2.12

BlockdevOptionsSsh (Object)

Members

server: InetSocketAddress

host address

path: string

path to the image on the host

user: string (optional)

user as which to connect, defaults to current local user name

host-key-check: SshHostKeyCheck (optional)

Defines how and what to check the host key against (default: known_hosts)

Since

2.9

BlkdebugEvent (Enum)

Trigger events supported by blkdebug.

Values

l1_shrink_write_table

write zeros to the l1 table to shrink image. (since 2.11)

l1_shrink_free_l2_clusters

discard the l2 tables. (since 2.11)

cor_write

a write due to copy-on-read (since 2.11)

cluster_alloc_space

an allocation of file space for a cluster (since 4.1)

none

triggers once at creation of the blkdebug node (since 4.1)

l1_update

Not documented

l1_grow_alloc_table

Not documented

l1_grow_write_table

Not documented

l1_grow_activate_table

Not documented

l2_load

Not documented

l2_update

Not documented

l2_update_compressed

Not documented

l2_alloc_cow_read

Not documented

l2_alloc_write

Not documented

read_aio

Not documented

read_backing_aio

Not documented

read_compressed

Not documented

write_aio

Not documented

write_compressed

Not documented

vmstate_load

Not documented

vmstate_save

Not documented

cow_read

Not documented

cow_write

Not documented

reftable_load

Not documented

reftable_grow

Not documented

reftable_update

Not documented

refblock_load

Not documented

refblock_update

Not documented

refblock_update_part

Not documented

refblock_alloc

Not documented

refblock_alloc_hookup

Not documented

refblock_alloc_write

Not documented

refblock_alloc_write_blocks

Not documented

refblock_alloc_write_table

Not documented

refblock_alloc_switch_table

Not documented

cluster_alloc

Not documented

cluster_alloc_bytes

Not documented

cluster_free

Not documented

flush_to_os

Not documented

flush_to_disk

Not documented

pwritev_rmw_head

Not documented

pwritev_rmw_after_head

Not documented

pwritev_rmw_tail

Not documented

pwritev_rmw_after_tail

Not documented

pwritev

Not documented

pwritev_zero

Not documented

pwritev_done

Not documented

empty_image_prepare

Not documented

Since

2.9

BlkdebugIOType (Enum)

Kinds of I/O that blkdebug can inject errors in.

Values

read

.bdrv_co_preadv()

write

.bdrv_co_pwritev()

write-zeroes

.bdrv_co_pwrite_zeroes()

discard

.bdrv_co_pdiscard()

flush

.bdrv_co_flush_to_disk()

block-status

.bdrv_co_block_status()

Since

4.1

BlkdebugInjectErrorOptions (Object)

Describes a single error injection for blkdebug.

Members

event: BlkdebugEvent

trigger event

state: int (optional)

the state identifier blkdebug needs to be in to actually trigger the event; defaults to “any”

iotype: BlkdebugIOType (optional)

the type of I/O operations on which this error should be injected; defaults to “all read, write, write-zeroes, discard, and flush operations” (since: 4.1)

errno: int (optional)

error identifier (errno) to be returned; defaults to EIO

sector: int (optional)

specifies the sector index which has to be affected in order to actually trigger the event; defaults to “any sector”

once: boolean (optional)

disables further events after this one has been triggered; defaults to false

immediately: boolean (optional)

fail immediately; defaults to false

Since

2.9

BlkdebugSetStateOptions (Object)

Describes a single state-change event for blkdebug.

Members

event: BlkdebugEvent

trigger event

state: int (optional)

the current state identifier blkdebug needs to be in; defaults to “any”

new_state: int

the state identifier blkdebug is supposed to assume if this event is triggered

Since

2.9

BlockdevOptionsBlkdebug (Object)

Driver specific block device options for blkdebug.

Members

image: BlockdevRef

underlying raw block device (or image file)

config: string (optional)

filename of the configuration file

align: int (optional)

required alignment for requests in bytes, must be positive power of 2, or 0 for default

max-transfer: int (optional)

maximum size for I/O transfers in bytes, must be positive multiple of align and of the underlying file’s request alignment (but need not be a power of 2), or 0 for default (since 2.10)

opt-write-zero: int (optional)

preferred alignment for write zero requests in bytes, must be positive multiple of align and of the underlying file’s request alignment (but need not be a power of 2), or 0 for default (since 2.10)

max-write-zero: int (optional)

maximum size for write zero requests in bytes, must be positive multiple of align, of opt-write-zero, and of the underlying file’s request alignment (but need not be a power of 2), or 0 for default (since 2.10)

opt-discard: int (optional)

preferred alignment for discard requests in bytes, must be positive multiple of align and of the underlying file’s request alignment (but need not be a power of 2), or 0 for default (since 2.10)

max-discard: int (optional)

maximum size for discard requests in bytes, must be positive multiple of align, of opt-discard, and of the underlying file’s request alignment (but need not be a power of 2), or 0 for default (since 2.10)

inject-error: array of BlkdebugInjectErrorOptions (optional)

array of error injection descriptions

set-state: array of BlkdebugSetStateOptions (optional)

array of state-change descriptions

take-child-perms: array of BlockPermission (optional)

Permissions to take on image in addition to what is necessary anyway (which depends on how the blkdebug node is used). Defaults to none. (since 5.0)

unshare-child-perms: array of BlockPermission (optional)

Permissions not to share on image in addition to what cannot be shared anyway (which depends on how the blkdebug node is used). Defaults to none. (since 5.0)

Since

2.9

BlockdevOptionsBlklogwrites (Object)

Driver specific block device options for blklogwrites.

Members

file: BlockdevRef

block device

log: BlockdevRef

block device used to log writes to file

log-sector-size: int (optional)

sector size used in logging writes to file, determines granularity of offsets and sizes of writes (default: 512)

log-append: boolean (optional)

append to an existing log (default: false)

log-super-update-interval: int (optional)

interval of write requests after which the log super block is updated to disk (default: 4096)

Since

3.0

BlockdevOptionsBlkverify (Object)

Driver specific block device options for blkverify.

Members

test: BlockdevRef

block device to be tested

raw: BlockdevRef

raw image used for verification

Since

2.9

BlockdevOptionsBlkreplay (Object)

Driver specific block device options for blkreplay.

Members

image: BlockdevRef

disk image which should be controlled with blkreplay

Since

4.2

QuorumReadPattern (Enum)

An enumeration of quorum read patterns.

Values

quorum

read all the children and do a quorum vote on reads

fifo

read only from the first child that has not failed

Since

2.9

BlockdevOptionsQuorum (Object)

Driver specific block device options for Quorum

Members

blkverify: boolean (optional)

true if the driver must print content mismatch set to false by default

children: array of BlockdevRef

the children block devices to use

vote-threshold: int

the vote limit under which a read will fail

rewrite-corrupted: boolean (optional)

rewrite corrupted data when quorum is reached (Since 2.1)

read-pattern: QuorumReadPattern (optional)

choose read pattern and set to quorum by default (Since 2.2)

Since

2.9

BlockdevOptionsGluster (Object)

Driver specific block device options for Gluster

Members

volume: string

name of gluster volume where VM image resides

path: string

absolute path to image file in gluster volume

server: array of SocketAddress

gluster servers description

debug: int (optional)

libgfapi log level (default ‘4’ which is Error) (Since 2.8)

logfile: string (optional)

libgfapi log file (default /dev/stderr) (Since 2.8)

Since

2.9

BlockdevOptionsIoUring (Object)

Driver specific block device options for the io_uring backend.

Members

filename: string

path to the image file

Since

7.2

If

CONFIG_BLKIO

BlockdevOptionsNvmeIoUring (Object)

Driver specific block device options for the nvme-io_uring backend.

Members

path: string

path to the NVMe namespace’s character device (e.g. /dev/ng0n1).

Since

7.2

If

CONFIG_BLKIO

BlockdevOptionsVirtioBlkVfioPci (Object)

Driver specific block device options for the virtio-blk-vfio-pci backend.

Members

path: string

path to the PCI device’s sysfs directory (e.g. /sys/bus/pci/devices/0000:00:01.0).

Since

7.2

If

CONFIG_BLKIO

BlockdevOptionsVirtioBlkVhostUser (Object)

Driver specific block device options for the virtio-blk-vhost-user backend.

Members

path: string

path to the vhost-user UNIX domain socket.

Since

7.2

If

CONFIG_BLKIO

BlockdevOptionsVirtioBlkVhostVdpa (Object)

Driver specific block device options for the virtio-blk-vhost-vdpa backend.

Members

path: string

path to the vhost-vdpa character device.

Features

fdset

Member path supports the special “/dev/fdset/N” path (since 8.1)

Since

7.2

If

CONFIG_BLKIO

IscsiTransport (Enum)

An enumeration of libiscsi transport types

Values

tcp

Not documented

iser

Not documented

Since

2.9

IscsiHeaderDigest (Enum)

An enumeration of header digests supported by libiscsi

Values

crc32c

Not documented

none

Not documented

crc32c-none

Not documented

none-crc32c

Not documented

Since

2.9

BlockdevOptionsIscsi (Object)

Driver specific block device options for iscsi

Members

transport: IscsiTransport

The iscsi transport type

portal: string

The address of the iscsi portal

target: string

The target iqn name

lun: int (optional)

LUN to connect to. Defaults to 0.

user: string (optional)

User name to log in with. If omitted, no CHAP authentication is performed.

password-secret: string (optional)

The ID of a QCryptoSecret object providing the password for the login. This option is required if user is specified.

initiator-name: string (optional)

The iqn name we want to identify to the target as. If this option is not specified, an initiator name is generated automatically.

header-digest: IscsiHeaderDigest (optional)

The desired header digest. Defaults to none-crc32c.

timeout: int (optional)

Timeout in seconds after which a request will timeout. 0 means no timeout and is the default.

Since

2.9

RbdAuthMode (Enum)

Values

cephx

Not documented

none

Not documented

Since

3.0

RbdImageEncryptionFormat (Enum)

Values

luks-any

Used for opening either luks or luks2 (Since 8.0)

luks

Not documented

luks2

Not documented

Since

6.1

RbdEncryptionOptionsLUKSBase (Object)

Members

key-secret: string

ID of a QCryptoSecret object providing a passphrase for unlocking the encryption

Since

6.1

RbdEncryptionCreateOptionsLUKSBase (Object)

Members

cipher-alg: QCryptoCipherAlgo (optional)

The encryption algorithm

The members of RbdEncryptionOptionsLUKSBase

Since

6.1

RbdEncryptionOptionsLUKS (Object)

Members

The members of RbdEncryptionOptionsLUKSBase

Since

6.1

RbdEncryptionOptionsLUKS2 (Object)

Members

The members of RbdEncryptionOptionsLUKSBase

Since

6.1

RbdEncryptionOptionsLUKSAny (Object)

Members

The members of RbdEncryptionOptionsLUKSBase

Since

8.0

RbdEncryptionCreateOptionsLUKS (Object)

Members

The members of RbdEncryptionCreateOptionsLUKSBase

Since

6.1

RbdEncryptionCreateOptionsLUKS2 (Object)

Members

The members of RbdEncryptionCreateOptionsLUKSBase

Since

6.1

RbdEncryptionOptions (Object)

Members

format: RbdImageEncryptionFormat

Encryption format.

parent: RbdEncryptionOptions (optional)

Parent image encryption options (for cloned images). Can be left unspecified if this cloned image is encrypted using the same format and secret as its parent image (i.e. not explicitly formatted) or if its parent image is not encrypted. (Since 8.0)

The members of RbdEncryptionOptionsLUKS when format is "luks"

The members of RbdEncryptionOptionsLUKS2 when format is "luks2"

The members of RbdEncryptionOptionsLUKSAny when format is "luks-any"

Since

6.1

RbdEncryptionCreateOptions (Object)

Members

format: RbdImageEncryptionFormat

Encryption format.

The members of RbdEncryptionCreateOptionsLUKS when format is "luks"

The members of RbdEncryptionCreateOptionsLUKS2 when format is "luks2"

Since

6.1

BlockdevOptionsRbd (Object)

Members

pool: string

Ceph pool name.

namespace: string (optional)

Rados namespace name in the Ceph pool. (Since 5.0)

image: string

Image name in the Ceph pool.

conf: string (optional)

path to Ceph configuration file. Values in the configuration file will be overridden by options specified via QAPI.

snapshot: string (optional)

Ceph snapshot name.

encrypt: RbdEncryptionOptions (optional)

Image encryption options. (Since 6.1)

user: string (optional)

Ceph id name.

auth-client-required: array of RbdAuthMode (optional)

Acceptable authentication modes. This maps to Ceph configuration option “auth_client_required”. (Since 3.0)

key-secret: string (optional)

ID of a QCryptoSecret object providing a key for cephx authentication. This maps to Ceph configuration option “key”. (Since 3.0)

server: array of InetSocketAddressBase (optional)

Monitor host address and port. This maps to the “mon_host” Ceph option.

Since

2.9

ReplicationMode (Enum)

An enumeration of replication modes.

Values

primary

Primary mode, the vm’s state will be sent to secondary QEMU.

secondary

Secondary mode, receive the vm’s state from primary QEMU.

Since

2.9

If

CONFIG_REPLICATION

BlockdevOptionsReplication (Object)

Driver specific block device options for replication

Members

mode: ReplicationMode

the replication mode

top-id: string (optional)

In secondary mode, node name or device ID of the root node who owns the replication node chain. Must not be given in primary mode.

The members of BlockdevOptionsGenericFormat

Since

2.9

If

CONFIG_REPLICATION

NFSTransport (Enum)

An enumeration of NFS transport types

Values

inet

TCP transport

Since

2.9

NFSServer (Object)

Captures the address of the socket

Members

type: NFSTransport

transport type used for NFS (only TCP supported)

host: string

host address for NFS server

Since

2.9

BlockdevOptionsNfs (Object)

Driver specific block device option for NFS

Members

server: NFSServer

host address

path: string

path of the image on the host

user: int (optional)

UID value to use when talking to the server (defaults to 65534 on Windows and getuid() on unix)

group: int (optional)

GID value to use when talking to the server (defaults to 65534 on Windows and getgid() in unix)

tcp-syn-count: int (optional)

number of SYNs during the session establishment (defaults to libnfs default)

readahead-size: int (optional)

set the readahead size in bytes (defaults to libnfs default)

page-cache-size: int (optional)

set the pagecache size in bytes (defaults to libnfs default)

debug: int (optional)

set the NFS debug level (max 2) (defaults to libnfs default)

Since

2.9

BlockdevOptionsCurlBase (Object)

Driver specific block device options shared by all protocols supported by the curl backend.

Members

url: string

URL of the image file

readahead: int (optional)

Size of the read-ahead cache; must be a multiple of 512 (defaults to 256 kB)

timeout: int (optional)

Timeout for connections, in seconds (defaults to 5)

username: string (optional)

Username for authentication (defaults to none)

password-secret: string (optional)

ID of a QCryptoSecret object providing a password for authentication (defaults to no password)

proxy-username: string (optional)

Username for proxy authentication (defaults to none)

proxy-password-secret: string (optional)

ID of a QCryptoSecret object providing a password for proxy authentication (defaults to no password)

Since

2.9

BlockdevOptionsCurlHttp (Object)

Driver specific block device options for HTTP connections over the curl backend. URLs must start with “http://”.

Members

cookie: string (optional)

List of cookies to set; format is “name1=content1; name2=content2;” as explained by CURLOPT_COOKIE(3). Defaults to no cookies.

cookie-secret: string (optional)

ID of a QCryptoSecret object providing the cookie data in a secure way. See cookie for the format. (since 2.10)

The members of BlockdevOptionsCurlBase

Since

2.9

BlockdevOptionsCurlHttps (Object)

Driver specific block device options for HTTPS connections over the curl backend. URLs must start with “https://”.

Members

cookie: string (optional)

List of cookies to set; format is “name1=content1; name2=content2;” as explained by CURLOPT_COOKIE(3). Defaults to no cookies.

sslverify: boolean (optional)

Whether to verify the SSL certificate’s validity (defaults to true)

cookie-secret: string (optional)

ID of a QCryptoSecret object providing the cookie data in a secure way. See cookie for the format. (since 2.10)

The members of BlockdevOptionsCurlBase

Since

2.9

BlockdevOptionsCurlFtp (Object)

Driver specific block device options for FTP connections over the curl backend. URLs must start with “ftp://”.

Members

The members of BlockdevOptionsCurlBase

Since

2.9

BlockdevOptionsCurlFtps (Object)

Driver specific block device options for FTPS connections over the curl backend. URLs must start with “ftps://”.

Members

sslverify: boolean (optional)

Whether to verify the SSL certificate’s validity (defaults to true)

The members of BlockdevOptionsCurlBase

Since

2.9

BlockdevOptionsNbd (Object)

Driver specific block device options for NBD.

Members

server: SocketAddress

NBD server address

export: string (optional)

export name

tls-creds: string (optional)

TLS credentials ID

tls-hostname: string (optional)

TLS hostname override for certificate validation (Since 7.0)

x-dirty-bitmap: string (optional)

A metadata context name such as “qemu:dirty-bitmap:NAME” or “qemu:allocation-depth” to query in place of the traditional “base:allocation” block status (see NBD_OPT_LIST_META_CONTEXT in the NBD protocol; and yes, naming this option x-context would have made more sense) (since 3.0)

reconnect-delay: int (optional)

On an unexpected disconnect, the nbd client tries to connect again until succeeding or encountering a serious error. During the first reconnect-delay seconds, all requests are paused and will be rerun on a successful reconnect. After that time, any delayed requests and all future requests before a successful reconnect will immediately fail. Default 0 (Since 4.2)

open-timeout: int (optional)

In seconds. If zero, the nbd driver tries the connection only once, and fails to open if the connection fails. If non-zero, the nbd driver will repeat connection attempts until successful or until open-timeout seconds have elapsed. Default 0 (Since 7.0)

Features

unstable

Member x-dirty-bitmap is experimental.

Since

2.9

BlockdevOptionsRaw (Object)

Driver specific block device options for the raw driver.

Members

offset: int (optional)

position where the block device starts

size: int (optional)

the assumed size of the device

The members of BlockdevOptionsGenericFormat

Since

2.9

BlockdevOptionsThrottle (Object)

Driver specific block device options for the throttle driver

Members

throttle-group: string

the name of the throttle-group object to use. It must already exist.

file: BlockdevRef

reference to or definition of the data source block device

Since

2.11

BlockdevOptionsCor (Object)

Driver specific block device options for the copy-on-read driver.

Members

bottom: string (optional)

The name of a non-filter node (allocation-bearing layer) that limits the COR operations in the backing chain (inclusive), so that no data below this node will be copied by this filter. If option is absent, the limit is not applied, so that data from all backing layers may be copied.

The members of BlockdevOptionsGenericFormat

Since

6.0

OnCbwError (Enum)

An enumeration of possible behaviors for copy-before-write operation failures.

Values

break-guest-write

report the error to the guest. This way, the guest will not be able to overwrite areas that cannot be backed up, so the backup process remains valid.

break-snapshot

continue guest write. Doing so will make the provided snapshot state invalid and any backup or export process based on it will finally fail.

Since

7.1

BlockdevOptionsCbw (Object)

Driver specific block device options for the copy-before-write driver, which does so called copy-before-write operations: when data is written to the filter, the filter first reads corresponding blocks from its file child and copies them to target child. After successfully copying, the write request is propagated to file child. If copying fails, the original write request is failed too and no data is written to file child.

Members

target: BlockdevRef

The target for copy-before-write operations.

bitmap: BlockDirtyBitmap (optional)

If specified, copy-before-write filter will do copy-before-write operations only for dirty regions of the bitmap. Bitmap size must be equal to length of file and target child of the filter. Note also, that bitmap is used only to initialize internal bitmap of the process, so further modifications (or removing) of specified bitmap doesn’t influence the filter. (Since 7.0)

on-cbw-error: OnCbwError (optional)

Behavior on failure of copy-before-write operation. Default is break-guest-write. (Since 7.1)

cbw-timeout: int (optional)

Zero means no limit. Non-zero sets the timeout in seconds for copy-before-write operation. When a timeout occurs, the respective copy-before-write operation will fail, and the on-cbw-error parameter will decide how this failure is handled. Default 0. (Since 7.1)

min-cluster-size: int (optional)

Minimum size of blocks used by copy-before-write operations. Has to be a power of 2. No effect if smaller than the maximum of the target’s cluster size and 64 KiB. Default 0. (Since 9.2)

The members of BlockdevOptionsGenericFormat

Since

6.2

BlockdevOptions (Object)

Options for creating a block device. Many options are available for all block devices, independent of the block driver:

Members

driver: BlockdevDriver

block driver name

node-name: string (optional)

the node name of the new node (Since 2.0). This option is required on the top level of blockdev-add. Valid node names start with an alphabetic character and may contain only alphanumeric characters, ‘-’, ‘.’ and ‘_’. Their maximum length is 31 characters.

discard: BlockdevDiscardOptions (optional)

discard-related options (default: ignore)

cache: BlockdevCacheOptions (optional)

cache-related options

read-only: boolean (optional)

whether the block device should be read-only (default: false). Note that some block drivers support only read-only access, either generally or in certain configurations. In this case, the default value does not work and the option must be specified explicitly.

auto-read-only: boolean (optional)

if true and read-only is false, QEMU may automatically decide not to open the image read-write as requested, but fall back to read-only instead (and switch between the modes later), e.g. depending on whether the image file is writable or whether a writing user is attached to the node (default: false, since 3.1)

detect-zeroes: BlockdevDetectZeroesOptions (optional)

detect and optimize zero writes (Since 2.1) (default: off)

force-share: boolean (optional)

force share all permission on added nodes. Requires read-only=true. (Since 2.10)

The members of BlockdevOptionsBlkdebug when driver is "blkdebug"

The members of BlockdevOptionsBlklogwrites when driver is "blklogwrites"

The members of BlockdevOptionsBlkverify when driver is "blkverify"

The members of BlockdevOptionsBlkreplay when driver is "blkreplay"

The members of BlockdevOptionsGenericFormat when driver is "bochs"

The members of BlockdevOptionsGenericFormat when driver is "cloop"

The members of BlockdevOptionsGenericFormat when driver is "compress"

The members of BlockdevOptionsCbw when driver is "copy-before-write"

The members of BlockdevOptionsCor when driver is "copy-on-read"

The members of BlockdevOptionsGenericFormat when driver is "dmg"

The members of BlockdevOptionsFile when driver is "file"

The members of BlockdevOptionsCurlFtp when driver is "ftp"

The members of BlockdevOptionsCurlFtps when driver is "ftps"

The members of BlockdevOptionsGluster when driver is "gluster"

The members of BlockdevOptionsFile when driver is "host_cdrom" (If: HAVE_HOST_BLOCK_DEVICE)

The members of BlockdevOptionsFile when driver is "host_device" (If: HAVE_HOST_BLOCK_DEVICE)

The members of BlockdevOptionsCurlHttp when driver is "http"

The members of BlockdevOptionsCurlHttps when driver is "https"

The members of BlockdevOptionsIoUring when driver is "io_uring" (If: CONFIG_BLKIO)

The members of BlockdevOptionsIscsi when driver is "iscsi"

The members of BlockdevOptionsLUKS when driver is "luks"

The members of BlockdevOptionsNbd when driver is "nbd"

The members of BlockdevOptionsNfs when driver is "nfs"

The members of BlockdevOptionsNull when driver is "null-aio"

The members of BlockdevOptionsNull when driver is "null-co"

The members of BlockdevOptionsNVMe when driver is "nvme"

The members of BlockdevOptionsNvmeIoUring when driver is "nvme-io_uring" (If: CONFIG_BLKIO)

The members of BlockdevOptionsGenericFormat when driver is "parallels"

The members of BlockdevOptionsPreallocate when driver is "preallocate"

The members of BlockdevOptionsQcow2 when driver is "qcow2"

The members of BlockdevOptionsQcow when driver is "qcow"

The members of BlockdevOptionsGenericCOWFormat when driver is "qed"

The members of BlockdevOptionsQuorum when driver is "quorum"

The members of BlockdevOptionsRaw when driver is "raw"

The members of BlockdevOptionsRbd when driver is "rbd"

The members of BlockdevOptionsReplication when driver is "replication" (If: CONFIG_REPLICATION)

The members of BlockdevOptionsGenericFormat when driver is "snapshot-access"

The members of BlockdevOptionsSsh when driver is "ssh"

The members of BlockdevOptionsThrottle when driver is "throttle"

The members of BlockdevOptionsGenericFormat when driver is "vdi"

The members of BlockdevOptionsGenericFormat when driver is "vhdx"

The members of BlockdevOptionsVirtioBlkVfioPci when driver is "virtio-blk-vfio-pci" (If: CONFIG_BLKIO)

The members of BlockdevOptionsVirtioBlkVhostUser when driver is "virtio-blk-vhost-user" (If: CONFIG_BLKIO)

The members of BlockdevOptionsVirtioBlkVhostVdpa when driver is "virtio-blk-vhost-vdpa" (If: CONFIG_BLKIO)

The members of BlockdevOptionsGenericCOWFormat when driver is "vmdk"

The members of BlockdevOptionsGenericFormat when driver is "vpc"

The members of BlockdevOptionsVVFAT when driver is "vvfat"

Since

2.9

BlockdevRef (Alternate)

Reference to a block device.

Members

definition: BlockdevOptions

defines a new block device inline

reference: string

references the ID of an existing block device

Since

2.9

BlockdevRefOrNull (Alternate)

Reference to a block device.

Members

definition: BlockdevOptions

defines a new block device inline

reference: string

references the ID of an existing block device. An empty string means that no block device should be referenced. Deprecated; use null instead.

null: null

No block device should be referenced (since 2.10)

Since

2.9

blockdev-add (Command)

Creates a new block device.

Arguments

The members of BlockdevOptions

Since

2.9

Example:

-> { "execute": "blockdev-add",
     "arguments": {
          "driver": "qcow2",
          "node-name": "test1",
          "file": {
              "driver": "file",
              "filename": "test.qcow2"
           }
      }
    }
<- { "return": {} }

Example:

-> { "execute": "blockdev-add",
     "arguments": {
          "driver": "qcow2",
          "node-name": "node0",
          "discard": "unmap",
          "cache": {
             "direct": true
           },
           "file": {
             "driver": "file",
             "filename": "/tmp/test.qcow2"
           },
           "backing": {
              "driver": "raw",
              "file": {
                 "driver": "file",
                 "filename": "/dev/fdset/4"
               }
           }
       }
     }

<- { "return": {} }

blockdev-reopen (Command)

Reopens one or more block devices using the given set of options. Any option not specified will be reset to its default value regardless of its previous status. If an option cannot be changed or a particular driver does not support reopening then the command will return an error. All devices in the list are reopened in one transaction, so if one of them fails then the whole transaction is cancelled.

The command receives a list of block devices to reopen. For each one of them, the top-level node-name option (from BlockdevOptions) must be specified and is used to select the block device to be reopened. Other node-name options must be either omitted or set to the current name of the appropriate node. This command won’t change any node name and any attempt to do it will result in an error.

In the case of options that refer to child nodes, the behavior of this command depends on the value:

1. A set of options (BlockdevOptions): the child is reopened with the specified set of options.

2. A reference to the current child: the child is reopened using its existing set of options.

3. A reference to a different node: the current child is replaced with the specified one.

4. NULL: the current child (if any) is detached.

Options (1) and (2) are supported in all cases. Option (3) is supported for file and backing, and option (4) for backing only.

Unlike with blockdev-add, the backing option must always be present unless the node being reopened does not have a backing file and its image does not have a default backing file name as part of its metadata.

Arguments

options: array of BlockdevOptions

Not documented

Since

6.1

blockdev-del (Command)

Deletes a block device that has been added using blockdev-add. The command will fail if the node is attached to a device or is otherwise being used.

Arguments

node-name: string

Name of the graph node to delete.

Since

2.9

Example:

-> { "execute": "blockdev-add",
     "arguments": {
          "driver": "qcow2",
          "node-name": "node0",
          "file": {
              "driver": "file",
              "filename": "test.qcow2"
          }
     }
   }
<- { "return": {} }

-> { "execute": "blockdev-del",
     "arguments": { "node-name": "node0" }
   }
<- { "return": {} }

BlockdevCreateOptionsFile (Object)

Driver specific image creation options for file.

Members

filename: string

Filename for the new image file

size: int

Size of the virtual disk in bytes

preallocation: PreallocMode (optional)

Preallocation mode for the new image (default: off; allowed values: off, falloc (if CONFIG_POSIX_FALLOCATE), full (if CONFIG_POSIX))

nocow: boolean (optional)

Turn off copy-on-write (valid only on btrfs; default: off)

extent-size-hint: int (optional)

Extent size hint to add to the image file; 0 for not adding an extent size hint (default: 1 MB, since 5.1)

Since

2.12

BlockdevCreateOptionsGluster (Object)

Driver specific image creation options for gluster.

Members

location: BlockdevOptionsGluster

Where to store the new image file

size: int

Size of the virtual disk in bytes

preallocation: PreallocMode (optional)

Preallocation mode for the new image (default: off; allowed values: off, falloc (if CONFIG_GLUSTERFS_FALLOCATE), full (if CONFIG_GLUSTERFS_ZEROFILL))

Since

2.12

BlockdevCreateOptionsLUKS (Object)

Driver specific image creation options for LUKS.

Members

file: BlockdevRef (optional)

Node to create the image format on, mandatory except when ‘preallocation’ is not requested

header: BlockdevRef (optional)

Block device holding a detached LUKS header. (since 9.0)

size: int

Size of the virtual disk in bytes

preallocation: PreallocMode (optional)

Preallocation mode for the new image (since: 4.2) (default: off; allowed values: off, metadata, falloc, full)

The members of QCryptoBlockCreateOptionsLUKS

Since

2.12

BlockdevCreateOptionsNfs (Object)

Driver specific image creation options for NFS.

Members

location: BlockdevOptionsNfs

Where to store the new image file

size: int

Size of the virtual disk in bytes

Since

2.12

BlockdevCreateOptionsParallels (Object)

Driver specific image creation options for parallels.

Members

file: BlockdevRef

Node to create the image format on

size: int

Size of the virtual disk in bytes

cluster-size: int (optional)

Cluster size in bytes (default: 1 MB)

Since

2.12

BlockdevCreateOptionsQcow (Object)

Driver specific image creation options for qcow.

Members

file: BlockdevRef

Node to create the image format on

size: int

Size of the virtual disk in bytes

backing-file: string (optional)

File name of the backing file if a backing file should be used

encrypt: QCryptoBlockCreateOptions (optional)

Encryption options if the image should be encrypted

Since

2.12

BlockdevQcow2Version (Enum)

Values

v2

The original QCOW2 format as introduced in qemu 0.10 (version 2)

v3

The extended QCOW2 format as introduced in qemu 1.1 (version 3)

Since

2.12

Qcow2CompressionType (Enum)

Compression type used in qcow2 image file

Values

zlib

zlib compression, see <http://zlib.net/>

zstd (If: CONFIG_ZSTD)

zstd compression, see <http://github.com/facebook/zstd>

Since

5.1

BlockdevCreateOptionsQcow2 (Object)

Driver specific image creation options for qcow2.

Members

file: BlockdevRef

Node to create the image format on

data-file: BlockdevRef (optional)

Node to use as an external data file in which all guest data is stored so that only metadata remains in the qcow2 file (since: 4.0)

data-file-raw: boolean (optional)

True if the external data file must stay valid as a standalone (read-only) raw image without looking at qcow2 metadata (default: false; since: 4.0)

extended-l2: boolean (optional)

True to make the image have extended L2 entries (default: false; since 5.2)

size: int

Size of the virtual disk in bytes

version: BlockdevQcow2Version (optional)

Compatibility level (default: v3)

backing-file: string (optional)

File name of the backing file if a backing file should be used

backing-fmt: BlockdevDriver (optional)

Name of the block driver to use for the backing file

encrypt: QCryptoBlockCreateOptions (optional)

Encryption options if the image should be encrypted

cluster-size: int (optional)

qcow2 cluster size in bytes (default: 65536)

preallocation: PreallocMode (optional)

Preallocation mode for the new image (default: off; allowed values: off, falloc, full, metadata)

lazy-refcounts: boolean (optional)

True if refcounts may be updated lazily (default: off)

refcount-bits: int (optional)

Width of reference counts in bits (default: 16)

compression-type: Qcow2CompressionType (optional)

The image cluster compression method (default: zlib, since 5.1)

Since

2.12

BlockdevCreateOptionsQed (Object)

Driver specific image creation options for qed.

Members

file: BlockdevRef

Node to create the image format on

size: int

Size of the virtual disk in bytes

backing-file: string (optional)

File name of the backing file if a backing file should be used

backing-fmt: BlockdevDriver (optional)

Name of the block driver to use for the backing file

cluster-size: int (optional)

Cluster size in bytes (default: 65536)

table-size: int (optional)

L1/L2 table size (in clusters)

Since

2.12

BlockdevCreateOptionsRbd (Object)

Driver specific image creation options for rbd/Ceph.

Members

location: BlockdevOptionsRbd

Where to store the new image file. This location cannot point to a snapshot.

size: int

Size of the virtual disk in bytes

cluster-size: int (optional)

RBD object size

encrypt: RbdEncryptionCreateOptions (optional)

Image encryption options. (Since 6.1)

Since

2.12

BlockdevVmdkSubformat (Enum)

Subformat options for VMDK images

Values

monolithicSparse

Single file image with sparse cluster allocation

monolithicFlat

Single flat data image and a descriptor file

twoGbMaxExtentSparse

Data is split into 2GB (per virtual LBA) sparse extent files, in addition to a descriptor file

twoGbMaxExtentFlat

Data is split into 2GB (per virtual LBA) flat extent files, in addition to a descriptor file

streamOptimized

Single file image sparse cluster allocation, optimized for streaming over network.

Since

4.0

BlockdevVmdkAdapterType (Enum)

Adapter type info for VMDK images

Values

ide

Not documented

buslogic

Not documented

lsilogic

Not documented

legacyESX

Not documented

Since

4.0

BlockdevCreateOptionsVmdk (Object)

Driver specific image creation options for VMDK.

Members

file: BlockdevRef

Where to store the new image file. This refers to the image file for monolithcSparse and streamOptimized format, or the descriptor file for other formats.

size: int

Size of the virtual disk in bytes

extents: array of BlockdevRef (optional)

Where to store the data extents. Required for monolithcFlat, twoGbMaxExtentSparse and twoGbMaxExtentFlat formats. For monolithicFlat, only one entry is required; for twoGbMaxExtent* formats, the number of entries required is calculated as extent_number = virtual_size / 2GB. Providing more extents than will be used is an error.

subformat: BlockdevVmdkSubformat (optional)

The subformat of the VMDK image. Default: “monolithicSparse”.

backing-file: string (optional)

The path of backing file. Default: no backing file is used.

adapter-type: BlockdevVmdkAdapterType (optional)

The adapter type used to fill in the descriptor. Default: ide.

hwversion: string (optional)

Hardware version. The meaningful options are “4” or “6”. Default: “4”.

toolsversion: string (optional)

VMware guest tools version. Default: “2147483647” (Since 6.2)

zeroed-grain: boolean (optional)

Whether to enable zeroed-grain feature for sparse subformats. Default: false.

Since

4.0

BlockdevCreateOptionsSsh (Object)

Driver specific image creation options for SSH.

Members

location: BlockdevOptionsSsh

Where to store the new image file

size: int

Size of the virtual disk in bytes

Since

2.12

BlockdevCreateOptionsVdi (Object)

Driver specific image creation options for VDI.

Members

file: BlockdevRef

Node to create the image format on

size: int

Size of the virtual disk in bytes

preallocation: PreallocMode (optional)

Preallocation mode for the new image (default: off; allowed values: off, metadata)

Since

2.12

BlockdevVhdxSubformat (Enum)

Values

dynamic

Growing image file

fixed

Preallocated fixed-size image file

Since

2.12

BlockdevCreateOptionsVhdx (Object)

Driver specific image creation options for vhdx.

Members

file: BlockdevRef

Node to create the image format on

size: int

Size of the virtual disk in bytes

log-size: int (optional)

Log size in bytes, must be a multiple of 1 MB (default: 1 MB)

block-size: int (optional)

Block size in bytes, must be a multiple of 1 MB and not larger than 256 MB (default: automatically choose a block size depending on the image size)

subformat: BlockdevVhdxSubformat (optional)

vhdx subformat (default: dynamic)

block-state-zero: boolean (optional)

Force use of payload blocks of type ‘ZERO’. Non-standard, but default. Do not set to ‘off’ when using ‘qemu-img convert’ with subformat=dynamic.

Since

2.12

BlockdevVpcSubformat (Enum)

Values

dynamic

Growing image file

fixed

Preallocated fixed-size image file

Since

2.12

BlockdevCreateOptionsVpc (Object)

Driver specific image creation options for vpc (VHD).

Members

file: BlockdevRef

Node to create the image format on

size: int

Size of the virtual disk in bytes

subformat: BlockdevVpcSubformat (optional)

vhdx subformat (default: dynamic)

force-size: boolean (optional)

Force use of the exact byte size instead of rounding to the next size that can be represented in CHS geometry (default: false)

Since

2.12

BlockdevCreateOptions (Object)

Options for creating an image format on a given node.

Members

driver: BlockdevDriver

block driver to create the image format

The members of BlockdevCreateOptionsFile when driver is "file"

The members of BlockdevCreateOptionsGluster when driver is "gluster"

The members of BlockdevCreateOptionsLUKS when driver is "luks"

The members of BlockdevCreateOptionsNfs when driver is "nfs"

The members of BlockdevCreateOptionsParallels when driver is "parallels"

The members of BlockdevCreateOptionsQcow when driver is "qcow"

The members of BlockdevCreateOptionsQcow2 when driver is "qcow2"

The members of BlockdevCreateOptionsQed when driver is "qed"

The members of BlockdevCreateOptionsRbd when driver is "rbd"

The members of BlockdevCreateOptionsSsh when driver is "ssh"

The members of BlockdevCreateOptionsVdi when driver is "vdi"

The members of BlockdevCreateOptionsVhdx when driver is "vhdx"

The members of BlockdevCreateOptionsVmdk when driver is "vmdk"

The members of BlockdevCreateOptionsVpc when driver is "vpc"

Since

2.12

blockdev-create (Command)

Starts a job to create an image format on a given node. The job is automatically finalized, but a manual job-dismiss is required.

Arguments

job-id: string

Identifier for the newly created job.

options: BlockdevCreateOptions

Options for the image creation.

Since

3.0

BlockdevAmendOptionsLUKS (Object)

Driver specific image amend options for LUKS.

Members

The members of QCryptoBlockAmendOptionsLUKS

Since

5.1

BlockdevAmendOptionsQcow2 (Object)

Driver specific image amend options for qcow2. For now, only encryption options can be amended

Members

encrypt: QCryptoBlockAmendOptions (optional)

Encryption options to be amended

Since

5.1

BlockdevAmendOptions (Object)

Options for amending an image format

Members

driver: BlockdevDriver

Block driver of the node to amend.

The members of BlockdevAmendOptionsLUKS when driver is "luks"

The members of BlockdevAmendOptionsQcow2 when driver is "qcow2"

Since

5.1

x-blockdev-amend (Command)

Starts a job to amend format specific options of an existing open block device The job is automatically finalized, but a manual job-dismiss is required.

Arguments

job-id: string

Identifier for the newly created job.

node-name: string

Name of the block node to work on

options: BlockdevAmendOptions

Options (driver specific)

force: boolean (optional)

Allow unsafe operations, format specific For luks that allows erase of the last active keyslot (permanent loss of data), and replacement of an active keyslot (possible loss of data if IO error happens)

Features

unstable

This command is experimental.

Since

5.1

BlockErrorAction (Enum)

An enumeration of action that has been taken when a DISK I/O occurs

Values

ignore

error has been ignored

report

error has been reported to the device

stop

error caused VM to be stopped

Since

2.1

BLOCK_IMAGE_CORRUPTED (Event)

Emitted when a disk image is being marked corrupt. The image can be identified by its device or node name. The ‘device’ field is always present for compatibility reasons, but it can be empty (“”) if the image does not have a device name associated.

Arguments

device: string

device name. This is always present for compatibility reasons, but it can be empty (“”) if the image does not have a device name associated.

node-name: string (optional)

node name (Since: 2.4)

msg: string

informative message for human consumption, such as the kind of corruption being detected. It should not be parsed by machine as it is not guaranteed to be stable

offset: int (optional)

if the corruption resulted from an image access, this is the host’s access offset into the image

size: int (optional)

if the corruption resulted from an image access, this is the access size

fatal: boolean

if set, the image is marked corrupt and therefore unusable after this event and must be repaired (Since 2.2; before, every BLOCK_IMAGE_CORRUPTED event was fatal)

Note

If action is “stop”, a STOP event will eventually follow the BLOCK_IO_ERROR event.

Example:

<- { "event": "BLOCK_IMAGE_CORRUPTED",
     "data": { "device": "", "node-name": "drive", "fatal": false,
               "msg": "L2 table offset 0x2a2a2a00 unaligned (L1 index: 0)" },
     "timestamp": { "seconds": 1648243240, "microseconds": 906060 } }

Since

1.7

BLOCK_IO_ERROR (Event)

Emitted when a disk I/O error occurs

Arguments

qom-path: string

path to the device object in the QOM tree (since 9.2)

device: string

device name. This is always present for compatibility reasons, but it can be empty (“”) if the image does not have a device name associated.

node-name: string (optional)

node name. Note that errors may be reported for the root node that is directly attached to a guest device rather than for the node where the error occurred. The node name is not present if the drive is empty. (Since: 2.8)

operation: IoOperationType

I/O operation

action: BlockErrorAction

action that has been taken

nospace: boolean (optional)

true if I/O error was caused due to a no-space condition. This key is only present if query-block’s io-status is present, please see query-block documentation for more information (since: 2.2)

reason: string

human readable string describing the error cause. (This field is a debugging aid for humans, it should not be parsed by applications) (since: 2.2)

Note

If action is “stop”, a STOP event will eventually follow the BLOCK_IO_ERROR event.

Note

This event is rate-limited.

Since

0.13

Example:

<- { "event": "BLOCK_IO_ERROR",
     "data": { "qom-path": "/machine/unattached/device[0]",
               "device": "ide0-hd1",
               "node-name": "#block212",
               "operation": "write",
               "action": "stop",
               "reason": "No space left on device" },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

BLOCK_JOB_COMPLETED (Event)

Emitted when a block job has completed

Arguments

type: JobType

job type

device: string

The job identifier. Originally the device name but other values are allowed since QEMU 2.7

len: int

maximum progress value

offset: int

current progress value. On success this is equal to len. On failure this is less than len

speed: int

rate limit, bytes per second

error: string (optional)

error message. Only present on failure. This field contains a human-readable error message. There are no semantics other than that streaming has failed and clients should not try to interpret the error string

Since

1.1

Example:

<- { "event": "BLOCK_JOB_COMPLETED",
     "data": { "type": "stream", "device": "virtio-disk0",
               "len": 10737418240, "offset": 10737418240,
               "speed": 0 },
     "timestamp": { "seconds": 1267061043, "microseconds": 959568 } }

BLOCK_JOB_CANCELLED (Event)

Emitted when a block job has been cancelled

Arguments

type: JobType

job type

device: string

The job identifier. Originally the device name but other values are allowed since QEMU 2.7

len: int

maximum progress value

offset: int

current progress value. On success this is equal to len. On failure this is less than len

speed: int

rate limit, bytes per second

Since

1.1

Example:

<- { "event": "BLOCK_JOB_CANCELLED",
     "data": { "type": "stream", "device": "virtio-disk0",
               "len": 10737418240, "offset": 134217728,
               "speed": 0 },
     "timestamp": { "seconds": 1267061043, "microseconds": 959568 } }

BLOCK_JOB_ERROR (Event)

Emitted when a block job encounters an error

Arguments

device: string

The job identifier. Originally the device name but other values are allowed since QEMU 2.7

operation: IoOperationType

I/O operation

action: BlockErrorAction

action that has been taken

Since

1.3

Example:

<- { "event": "BLOCK_JOB_ERROR",
     "data": { "device": "ide0-hd1",
               "operation": "write",
               "action": "stop" },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

BLOCK_JOB_READY (Event)

Emitted when a block job is ready to complete

Arguments

type: JobType

job type

device: string

The job identifier. Originally the device name but other values are allowed since QEMU 2.7

len: int

maximum progress value

offset: int

current progress value. On success this is equal to len. On failure this is less than len

speed: int

rate limit, bytes per second

Note

The “ready to complete” status is always reset by a BLOCK_JOB_ERROR event.

Since

1.3

Example:

<- { "event": "BLOCK_JOB_READY",
     "data": { "device": "drive0", "type": "mirror", "speed": 0,
               "len": 2097152, "offset": 2097152 },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

BLOCK_JOB_PENDING (Event)

Emitted when a block job is awaiting explicit authorization to finalize graph changes via block-job-finalize. If this job is part of a transaction, it will not emit this event until the transaction has converged first.

Arguments

type: JobType

job type

id: string

The job identifier.

Since

2.12

Example:

<- { "event": "BLOCK_JOB_PENDING",
     "data": { "type": "mirror", "id": "backup_1" },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

PreallocMode (Enum)

Preallocation mode of QEMU image file

Values

off

no preallocation

metadata

preallocate only for metadata

falloc

like full preallocation but allocate disk space by posix_fallocate() rather than writing data.

full

preallocate all data by writing it to the device to ensure disk space is really available. This data may or may not be zero, depending on the image format and storage. full preallocation also sets up metadata correctly.

Since

2.2

BLOCK_WRITE_THRESHOLD (Event)

Emitted when writes on block device reaches or exceeds the configured write threshold. For thin-provisioned devices, this means the device should be extended to avoid pausing for disk exhaustion. The event is one shot. Once triggered, it needs to be re-registered with another block-set-write-threshold command.

Arguments

node-name: string

graph node name on which the threshold was exceeded.

amount-exceeded: int

amount of data which exceeded the threshold, in bytes.

write-threshold: int

last configured threshold, in bytes.

Since

2.3

block-set-write-threshold (Command)

Change the write threshold for a block drive. An event will be delivered if a write to this block drive crosses the configured threshold. The threshold is an offset, thus must be non-negative. Default is no write threshold. Setting the threshold to zero disables it.

This is useful to transparently resize thin-provisioned drives without the guest OS noticing.

Arguments

node-name: string

graph node name on which the threshold must be set.

write-threshold: int

configured threshold for the block device, bytes. Use 0 to disable the threshold.

Since

2.3

Example:

-> { "execute": "block-set-write-threshold",
     "arguments": { "node-name": "mydev",
                    "write-threshold": 17179869184 } }
<- { "return": {} }

x-blockdev-change (Command)

Dynamically reconfigure the block driver state graph. It can be used to add, remove, insert or replace a graph node. Currently only the Quorum driver implements this feature to add or remove its child. This is useful to fix a broken quorum child.

If node is specified, it will be inserted under parent. child may not be specified in this case. If both parent and child are specified but node is not, child will be detached from parent.

Arguments

parent: string

the id or name of the parent node.

child: string (optional)

the name of a child under the given parent node.

node: string (optional)

the name of the node that will be added.

Features

unstable

This command is experimental, and its API is not stable. It does not support all kinds of operations, all kinds of children, nor all block drivers.

FIXME Removing children from a quorum node means introducing gaps in the child indices. This cannot be represented in the ‘children’ list of BlockdevOptionsQuorum, as returned by .bdrv_refresh_filename().

Warning: The data in a new quorum child MUST be consistent with that of the rest of the array.

Since

2.7

Example: Add a new node to a quorum

 -> { "execute": "blockdev-add",
      "arguments": {
          "driver": "raw",
          "node-name": "new_node",
          "file": { "driver": "file",
                    "filename": "test.raw" } } }
 <- { "return": {} }
 -> { "execute": "x-blockdev-change",
      "arguments": { "parent": "disk1",
                     "node": "new_node" } }
 <- { "return": {} }

Example: Delete a quorum’s node

 -> { "execute": "x-blockdev-change",
      "arguments": { "parent": "disk1",
                     "child": "children.1" } }
 <- { "return": {} }

x-blockdev-set-iothread (Command)

Move node and its children into the iothread. If iothread is null then move node and its children into the main loop.

The node must not be attached to a BlockBackend.

Arguments

node-name: string

the name of the block driver node

iothread: StrOrNull

the name of the IOThread object or null for the main loop

force: boolean (optional)

true if the node and its children should be moved when a BlockBackend is already attached

Features

unstable

This command is experimental and intended for test cases that need control over IOThreads only.

Since

2.12

Example: Move a node into an IOThread

 -> { "execute": "x-blockdev-set-iothread",
      "arguments": { "node-name": "disk1",
                     "iothread": "iothread0" } }
 <- { "return": {} }

Example: Move a node into the main loop

 -> { "execute": "x-blockdev-set-iothread",
      "arguments": { "node-name": "disk1",
                     "iothread": null } }
 <- { "return": {} }

QuorumOpType (Enum)

An enumeration of the quorum operation types

Values

read

read operation

write

write operation

flush

flush operation

Since

2.6

QUORUM_FAILURE (Event)

Emitted by the Quorum block driver if it fails to establish a quorum

Arguments

reference: string

device name if defined else node name

sector-num: int

number of the first sector of the failed read operation

sectors-count: int

failed read operation sector count

Note

This event is rate-limited.

Since

2.0

Example:

<- { "event": "QUORUM_FAILURE",
     "data": { "reference": "usr1", "sector-num": 345435, "sectors-count": 5 },
     "timestamp": { "seconds": 1344522075, "microseconds": 745528 } }

QUORUM_REPORT_BAD (Event)

Emitted to report a corruption of a Quorum file

Arguments

type: QuorumOpType

quorum operation type (Since 2.6)

error: string (optional)

error message. Only present on failure. This field contains a human-readable error message. There are no semantics other than that the block layer reported an error and clients should not try to interpret the error string.

node-name: string

the graph node name of the block driver state

sector-num: int

number of the first sector of the failed read operation

sectors-count: int

failed read operation sector count

Note

This event is rate-limited.

Since

2.0

Example: Read operation

 <- { "event": "QUORUM_REPORT_BAD",
      "data": { "node-name": "node0", "sector-num": 345435, "sectors-count": 5,
                "type": "read" },
      "timestamp": { "seconds": 1344522075, "microseconds": 745528 } }

Example: Flush operation

 <- { "event": "QUORUM_REPORT_BAD",
      "data": { "node-name": "node0", "sector-num": 0, "sectors-count": 2097120,
                "type": "flush", "error": "Broken pipe" },
      "timestamp": { "seconds": 1456406829, "microseconds": 291763 } }

BlockdevSnapshotInternal (Object)

Members

device: string

the device name or node-name of a root node to generate the snapshot from

name: string

the name of the internal snapshot to be created

Since

1.7

blockdev-snapshot-internal-sync (Command)

Synchronously take an internal snapshot of a block device, when the format of the image used supports it. If the name is an empty string, or a snapshot with name already exists, the operation will fail.

Arguments

The members of BlockdevSnapshotInternal

Errors

• If device is not a valid block device, GenericError

• If any snapshot matching name exists, or name is empty, GenericError

• If the format of the image used does not support it, GenericError

Note

Only some image formats such as qcow2 and rbd support internal snapshots.

Since

1.7

Example:

-> { "execute": "blockdev-snapshot-internal-sync",
     "arguments": { "device": "ide-hd0",
                    "name": "snapshot0" }
   }
<- { "return": {} }

blockdev-snapshot-delete-internal-sync (Command)

Synchronously delete an internal snapshot of a block device, when the format of the image used support it. The snapshot is identified by name or id or both. One of the name or id is required. Return SnapshotInfo for the successfully deleted snapshot.

Arguments

device: string

the device name or node-name of a root node to delete the snapshot from

id: string (optional)

optional the snapshot’s ID to be deleted

name: string (optional)

optional the snapshot’s name to be deleted

Returns

SnapshotInfo

Errors

• If device is not a valid block device, GenericError

• If snapshot not found, GenericError

• If the format of the image used does not support it, GenericError

• If id and name are both not specified, GenericError

Since

1.7

Example:

-> { "execute": "blockdev-snapshot-delete-internal-sync",
     "arguments": { "device": "ide-hd0",
                    "name": "snapshot0" }
   }
<- { "return": {
                   "id": "1",
                   "name": "snapshot0",
                   "vm-state-size": 0,
                   "date-sec": 1000012,
                   "date-nsec": 10,
                   "vm-clock-sec": 100,
                   "vm-clock-nsec": 20,
                   "icount": 220414
     }
   }

DummyBlockCoreForceArrays (Object)

Not used by QMP; hack to let us use BlockGraphInfoList internally

Members

unused-block-graph-info: array of BlockGraphInfo

Not documented

Since

8.0

Additional block stuff (VM related)

BiosAtaTranslation (Enum)

Policy that BIOS should use to interpret cylinder/head/sector addresses. Note that Bochs BIOS and SeaBIOS will not actually translate logical CHS to physical; instead, they will use logical block addressing.

Values

auto

If cylinder/heads/sizes are passed, choose between none and LBA depending on the size of the disk. If they are not passed, choose none if QEMU can guess that the disk had 16 or fewer heads, large if QEMU can guess that the disk had 131072 or fewer tracks across all heads (i.e. cylinders*heads<131072), otherwise LBA.

none

The physical disk geometry is equal to the logical geometry.

lba

Assume 63 sectors per track and one of 16, 32, 64, 128 or 255 heads (if fewer than 255 are enough to cover the whole disk with 1024 cylinders/head). The number of cylinders/head is then computed based on the number of sectors and heads.

large

The number of cylinders per head is scaled down to 1024 by correspondingly scaling up the number of heads.

rechs

Same as large, but first convert a 16-head geometry to 15-head, by proportionally scaling up the number of cylinders/head.

Since

2.0

FloppyDriveType (Enum)

Type of Floppy drive to be emulated by the Floppy Disk Controller.

Values

144

1.44MB 3.5” drive

288

2.88MB 3.5” drive

120

1.2MB 5.25” drive

none

No drive connected

auto

Automatically determined by inserted media at boot

Since

2.6

PRManagerInfo (Object)

Information about a persistent reservation manager

Members

id: string

the identifier of the persistent reservation manager

connected: boolean

true if the persistent reservation manager is connected to the underlying storage or helper

Since

3.0

query-pr-managers (Command)

Returns a list of information about each persistent reservation manager.

Returns

a list of PRManagerInfo for each persistent reservation manager

Since

3.0

eject (Command)

Ejects the medium from a removable drive.

Arguments

device: string (optional)

Block device name

id: string (optional)

The name or QOM path of the guest device (since: 2.8)

force: boolean (optional)

If true, eject regardless of whether the drive is locked. If not specified, the default value is false.

Features

deprecated

Member device is deprecated. Use id instead.

Errors

• If device is not a valid block device, DeviceNotFound

Note

Ejecting a device with no media results in success.

Since

0.14

Example:

-> { "execute": "eject", "arguments": { "id": "ide1-0-1" } }
<- { "return": {} }

blockdev-open-tray (Command)

Opens a block device’s tray. If there is a block driver state tree inserted as a medium, it will become inaccessible to the guest (but it will remain associated to the block device, so closing the tray will make it accessible again).

If the tray was already open before, this will be a no-op.

Once the tray opens, a DEVICE_TRAY_MOVED event is emitted. There are cases in which no such event will be generated, these include:

• if the guest has locked the tray, force is false and the guest does not respond to the eject request

• if the BlockBackend denoted by device does not have a guest device attached to it

• if the guest device does not have an actual tray

Arguments

device: string (optional)

Block device name

id: string (optional)

The name or QOM path of the guest device (since: 2.8)

force: boolean (optional)

if false (the default), an eject request will be sent to the guest if it has locked the tray (and the tray will not be opened immediately); if true, the tray will be opened regardless of whether it is locked

Features

deprecated

Member device is deprecated. Use id instead.

Since

2.5

Example:

-> { "execute": "blockdev-open-tray",
     "arguments": { "id": "ide0-1-0" } }

<- { "timestamp": { "seconds": 1418751016,
                    "microseconds": 716996 },
     "event": "DEVICE_TRAY_MOVED",
     "data": { "device": "ide1-cd0",
               "id": "ide0-1-0",
               "tray-open": true } }

<- { "return": {} }

blockdev-close-tray (Command)

Closes a block device’s tray. If there is a block driver state tree associated with the block device (which is currently ejected), that tree will be loaded as the medium.

If the tray was already closed before, this will be a no-op.

Arguments

device: string (optional)

Block device name

id: string (optional)

The name or QOM path of the guest device (since: 2.8)

Features

deprecated

Member device is deprecated. Use id instead.

Since

2.5

Example:

-> { "execute": "blockdev-close-tray",
     "arguments": { "id": "ide0-1-0" } }

<- { "timestamp": { "seconds": 1418751345,
                    "microseconds": 272147 },
     "event": "DEVICE_TRAY_MOVED",
     "data": { "device": "ide1-cd0",
               "id": "ide0-1-0",
               "tray-open": false } }

<- { "return": {} }

blockdev-remove-medium (Command)

Removes a medium (a block driver state tree) from a block device. That block device’s tray must currently be open (unless there is no attached guest device).

If the tray is open and there is no medium inserted, this will be a no-op.

Arguments

id: string

The name or QOM path of the guest device

Since

2.12

Example:

-> { "execute": "blockdev-remove-medium",
     "arguments": { "id": "ide0-1-0" } }

<- { "error": { "class": "GenericError",
                "desc": "Tray of device 'ide0-1-0' is not open" } }

-> { "execute": "blockdev-open-tray",
     "arguments": { "id": "ide0-1-0" } }

<- { "timestamp": { "seconds": 1418751627,
                    "microseconds": 549958 },
     "event": "DEVICE_TRAY_MOVED",
     "data": { "device": "ide1-cd0",
               "id": "ide0-1-0",
               "tray-open": true } }

<- { "return": {} }

-> { "execute": "blockdev-remove-medium",
     "arguments": { "id": "ide0-1-0" } }

<- { "return": {} }

blockdev-insert-medium (Command)

Inserts a medium (a block driver state tree) into a block device. That block device’s tray must currently be open (unless there is no attached guest device) and there must be no medium inserted already.

Arguments

id: string

The name or QOM path of the guest device

node-name: string

name of a node in the block driver state graph

Since

2.12

Example:

-> { "execute": "blockdev-add",
     "arguments": {
         "node-name": "node0",
         "driver": "raw",
         "file": { "driver": "file",
                   "filename": "fedora.iso" } } }
<- { "return": {} }

-> { "execute": "blockdev-insert-medium",
     "arguments": { "id": "ide0-1-0",
                    "node-name": "node0" } }

<- { "return": {} }

BlockdevChangeReadOnlyMode (Enum)

Specifies the new read-only mode of a block device subject to the blockdev-change-medium command.

Values

retain

Retains the current read-only mode

read-only

Makes the device read-only

read-write

Makes the device writable

Since

2.3

blockdev-change-medium (Command)

Changes the medium inserted into a block device by ejecting the current medium and loading a new image file which is inserted as the new medium (this command combines blockdev-open-tray, blockdev-remove-medium, blockdev-insert-medium and blockdev-close-tray).

Arguments

device: string (optional)

Block device name

id: string (optional)

The name or QOM path of the guest device (since: 2.8)

filename: string

filename of the new image to be loaded

format: string (optional)

format to open the new image with (defaults to the probed format)

read-only-mode: BlockdevChangeReadOnlyMode (optional)

change the read-only mode of the device; defaults to ‘retain’

force: boolean (optional)

if false (the default), an eject request through blockdev-open-tray will be sent to the guest if it has locked the tray (and the tray will not be opened immediately); if true, the tray will be opened regardless of whether it is locked. (since 7.1)

Features

deprecated

Member device is deprecated. Use id instead.

Since

2.5

Example: Change a removable medium

 -> { "execute": "blockdev-change-medium",
      "arguments": { "id": "ide0-1-0",
                     "filename": "/srv/images/Fedora-12-x86_64-DVD.iso",
                     "format": "raw" } }
 <- { "return": {} }

Example: Load a read-only medium into a writable drive

 -> { "execute": "blockdev-change-medium",
      "arguments": { "id": "floppyA",
                     "filename": "/srv/images/ro.img",
                     "format": "raw",
                     "read-only-mode": "retain" } }

 <- { "error":
      { "class": "GenericError",
        "desc": "Could not open '/srv/images/ro.img': Permission denied" } }

 -> { "execute": "blockdev-change-medium",
      "arguments": { "id": "floppyA",
                     "filename": "/srv/images/ro.img",
                     "format": "raw",
                     "read-only-mode": "read-only" } }

 <- { "return": {} }

DEVICE_TRAY_MOVED (Event)

Emitted whenever the tray of a removable device is moved by the guest or by HMP/QMP commands

Arguments

device: string

Block device name. This is always present for compatibility reasons, but it can be empty (“”) if the image does not have a device name associated.

id: string

The name or QOM path of the guest device (since 2.8)

tray-open: boolean

true if the tray has been opened or false if it has been closed

Since

1.1

Example:

<- { "event": "DEVICE_TRAY_MOVED",
     "data": { "device": "ide1-cd0",
               "id": "/machine/unattached/device[22]",
               "tray-open": true
     },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

PR_MANAGER_STATUS_CHANGED (Event)

Emitted whenever the connected status of a persistent reservation manager changes.

Arguments

id: string

The id of the PR manager object

connected: boolean

true if the PR manager is connected to a backend

Since

3.0

Example:

<- { "event": "PR_MANAGER_STATUS_CHANGED",
     "data": { "id": "pr-helper0",
               "connected": true
     },
     "timestamp": { "seconds": 1519840375, "microseconds": 450486 } }

block_set_io_throttle (Command)

Change I/O throttle limits for a block drive.

Since QEMU 2.4, each device with I/O limits is member of a throttle group.

If two or more devices are members of the same group, the limits will apply to the combined I/O of the whole group in a round-robin fashion. Therefore, setting new I/O limits to a device will affect the whole group.

The name of the group can be specified using the ‘group’ parameter. If the parameter is unset, it is assumed to be the current group of that device. If it’s not in any group yet, the name of the device will be used as the name for its group.

The ‘group’ parameter can also be used to move a device to a different group. In this case the limits specified in the parameters will be applied to the new group only.

I/O limits can be disabled by setting all of them to 0. In this case the device will be removed from its group and the rest of its members will not be affected. The ‘group’ parameter is ignored.

Arguments

The members of BlockIOThrottle

Errors

• If device is not a valid block device, DeviceNotFound

Since

1.1

Example:

-> { "execute": "block_set_io_throttle",
     "arguments": { "id": "virtio-blk-pci0/virtio-backend",
                    "bps": 0,
                    "bps_rd": 0,
                    "bps_wr": 0,
                    "iops": 512,
                    "iops_rd": 0,
                    "iops_wr": 0,
                    "bps_max": 0,
                    "bps_rd_max": 0,
                    "bps_wr_max": 0,
                    "iops_max": 0,
                    "iops_rd_max": 0,
                    "iops_wr_max": 0,
                    "bps_max_length": 0,
                    "iops_size": 0 } }
<- { "return": {} }

Example:

-> { "execute": "block_set_io_throttle",
     "arguments": { "id": "ide0-1-0",
                    "bps": 1000000,
                    "bps_rd": 0,
                    "bps_wr": 0,
                    "iops": 0,
                    "iops_rd": 0,
                    "iops_wr": 0,
                    "bps_max": 8000000,
                    "bps_rd_max": 0,
                    "bps_wr_max": 0,
                    "iops_max": 0,
                    "iops_rd_max": 0,
                    "iops_wr_max": 0,
                    "bps_max_length": 60,
                    "iops_size": 0 } }
<- { "return": {} }

block-latency-histogram-set (Command)

Manage read, write and flush latency histograms for the device.

If only id parameter is specified, remove all present latency histograms for the device. Otherwise, add/reset some of (or all) latency histograms.

Arguments

id: string

The name or QOM path of the guest device.

boundaries: array of int (optional)

list of interval boundary values (see description in BlockLatencyHistogramInfo definition). If specified, all latency histograms are removed, and empty ones created for all io types with intervals corresponding to boundaries (except for io types, for which specific boundaries are set through the following parameters).

boundaries-read: array of int (optional)

list of interval boundary values for read latency histogram. If specified, old read latency histogram is removed, and empty one created with intervals corresponding to boundaries-read. The parameter has higher priority then boundaries.

boundaries-write: array of int (optional)

list of interval boundary values for write latency histogram.

boundaries-zap: array of int (optional)

list of interval boundary values for zone append write latency histogram.

boundaries-flush: array of int (optional)

list of interval boundary values for flush latency histogram.

Errors

• if device is not found or any boundary arrays are invalid.

Since

4.0

Example:

Set new histograms for all io types with intervals [0, 10), [10, 50), [50, 100), [100, +inf):

-> { "execute": "block-latency-histogram-set",
     "arguments": { "id": "drive0",
                    "boundaries": [10, 50, 100] } }
<- { "return": {} }

Example:

Set new histogram only for write, other histograms will remain not changed (or not created):

-> { "execute": "block-latency-histogram-set",
     "arguments": { "id": "drive0",
                    "boundaries-write": [10, 50, 100] } }
<- { "return": {} }

Example:

Set new histograms with the following intervals:

• read, flush: [0, 10), [10, 50), [50, 100), [100, +inf)

• write: [0, 1000), [1000, 5000), [5000, +inf)

-> { "execute": "block-latency-histogram-set",
     "arguments": { "id": "drive0",
                    "boundaries": [10, 50, 100],
                    "boundaries-write": [1000, 5000] } }
<- { "return": {} }

Example:

Remove all latency histograms:

-> { "execute": "block-latency-histogram-set",
     "arguments": { "id": "drive0" } }
<- { "return": {} }

Block device exports

NbdServerOptions (Object)

Keep this type consistent with the nbd-server-start arguments. The only intended difference is using SocketAddress instead of SocketAddressLegacy.

Members

addr: SocketAddress

Address on which to listen.

tls-creds: string (optional)

ID of the TLS credentials object (since 2.6).

tls-authz: string (optional)

ID of the QAuthZ authorization object used to validate the client’s x509 distinguished name. This object is is only resolved at time of use, so can be deleted and recreated on the fly while the NBD server is active. If missing, it will default to denying access (since 4.0).

max-connections: int (optional)

The maximum number of connections to allow at the same time, 0 for unlimited. Setting this to 1 also stops the server from advertising multiple client support (since 5.2; default: 100)

Since

4.2

nbd-server-start (Command)

Start an NBD server listening on the given host and port. Block devices can then be exported using nbd-server-add. The NBD server will present them as named exports; for example, another QEMU instance could refer to them as “nbd:HOST:PORT:exportname=NAME”.

Keep this type consistent with the NbdServerOptions type. The only intended difference is using SocketAddressLegacy instead of SocketAddress.

Arguments

addr: SocketAddressLegacy

Address on which to listen.

tls-creds: string (optional)

ID of the TLS credentials object (since 2.6).

tls-authz: string (optional)

ID of the QAuthZ authorization object used to validate the client’s x509 distinguished name. This object is is only resolved at time of use, so can be deleted and recreated on the fly while the NBD server is active. If missing, it will default to denying access (since 4.0).

max-connections: int (optional)

The maximum number of connections to allow at the same time, 0 for unlimited. Setting this to 1 also stops the server from advertising multiple client support (since 5.2; default: 100).

Errors

• if the server is already running

Since

1.3

BlockExportOptionsNbdBase (Object)

An NBD block export (common options shared between nbd-server-add and the NBD branch of block-export-add).

Members

name: string (optional)

Export name. If unspecified, the device parameter is used as the export name. (Since 2.12)

description: string (optional)

Free-form description of the export, up to 4096 bytes. (Since 5.0)

Since

5.0

BlockExportOptionsNbd (Object)

An NBD block export (distinct options used in the NBD branch of block-export-add).

Members

bitmaps: array of BlockDirtyBitmapOrStr (optional)

Also export each of the named dirty bitmaps reachable from device, so the NBD client can use NBD_OPT_SET_META_CONTEXT with the metadata context name “qemu:dirty-bitmap:BITMAP” to inspect each bitmap. Since 7.1 bitmap may be specified by node/name pair.

allocation-depth: boolean (optional)

Also export the allocation depth map for device, so the NBD client can use NBD_OPT_SET_META_CONTEXT with the metadata context name “qemu:allocation-depth” to inspect allocation details. (since 5.2)

The members of BlockExportOptionsNbdBase

Since

5.2

BlockExportOptionsVhostUserBlk (Object)

A vhost-user-blk block export.

Members

addr: SocketAddress

The vhost-user socket on which to listen. Both ‘unix’ and ‘fd’ SocketAddress types are supported. Passed fds must be UNIX domain sockets.

logical-block-size: int (optional)

Logical block size in bytes. Defaults to 512 bytes.

num-queues: int (optional)

Number of request virtqueues. Must be greater than 0. Defaults to 1.

Since

5.2

FuseExportAllowOther (Enum)

Possible allow_other modes for FUSE exports.

Values

off

Do not pass allow_other as a mount option.

on

Pass allow_other as a mount option.

auto

Try mounting with allow_other first, and if that fails, retry without allow_other.

Since

6.1

BlockExportOptionsFuse (Object)

Options for exporting a block graph node on some (file) mountpoint as a raw image.

Members

mountpoint: string

Path on which to export the block device via FUSE. This must point to an existing regular file.

growable: boolean (optional)

Whether writes beyond the EOF should grow the block node accordingly. (default: false)

allow-other: FuseExportAllowOther (optional)

If this is off, only qemu’s user is allowed access to this export. That cannot be changed even with chmod or chown. Enabling this option will allow other users access to the export with the FUSE mount option “allow_other”. Note that using allow_other as a non-root user requires user_allow_other to be enabled in the global fuse.conf configuration file. In auto mode (the default), the FUSE export driver will first attempt to mount the export with allow_other, and if that fails, try again without. (since 6.1; default: auto)

Since

6.0

If

CONFIG_FUSE

BlockExportOptionsVduseBlk (Object)

A vduse-blk block export.

Members

name: string

the name of VDUSE device (must be unique across the host).

num-queues: int (optional)

the number of virtqueues. Defaults to 1.

queue-size: int (optional)

the size of virtqueue. Defaults to 256.

logical-block-size: int (optional)

Logical block size in bytes. Range [512, PAGE_SIZE] and must be power of 2. Defaults to 512 bytes.

serial: string (optional)

the serial number of virtio block device. Defaults to empty string.

Since

7.1

NbdServerAddOptions (Object)

An NBD block export, per legacy nbd-server-add command.

Members

device: string

The device name or node name of the node to be exported

writable: boolean (optional)

Whether clients should be able to write to the device via the NBD connection (default false).

bitmap: string (optional)

Also export a single dirty bitmap reachable from device, so the NBD client can use NBD_OPT_SET_META_CONTEXT with the metadata context name “qemu:dirty-bitmap:BITMAP” to inspect the bitmap (since 4.0).

The members of BlockExportOptionsNbdBase

Since

5.0

nbd-server-add (Command)

Export a block node to QEMU’s embedded NBD server.

The export name will be used as the id for the resulting block export.

Arguments

The members of NbdServerAddOptions

Features

deprecated

This command is deprecated. Use block-export-add instead.

Errors

• if the server is not running

• if an export with the same name already exists

Since

1.3

BlockExportRemoveMode (Enum)

Mode for removing a block export.

Values

safe

Remove export if there are no existing connections, fail otherwise.

hard

Drop all connections immediately and remove export.

Since

2.12

nbd-server-remove (Command)

Remove NBD export by name.

Arguments

name: string

Block export id.

mode: BlockExportRemoveMode (optional)

Mode of command operation. See BlockExportRemoveMode description. Default is ‘safe’.

Features

deprecated

This command is deprecated. Use block-export-del instead.

Errors

• if the server is not running

• if export is not found

• if mode is ‘safe’ and there are existing connections

Since

2.12

nbd-server-stop (Command)

Stop QEMU’s embedded NBD server, and unregister all devices previously added via nbd-server-add.

Since

1.3

BlockExportType (Enum)

An enumeration of block export types

Values

nbd

NBD export

vhost-user-blk (If: CONFIG_VHOST_USER_BLK_SERVER)

vhost-user-blk export (since 5.2)

fuse (If: CONFIG_FUSE)

FUSE export (since: 6.0)

vduse-blk (If: CONFIG_VDUSE_BLK_EXPORT)

vduse-blk export (since 7.1)

Since

4.2

BlockExportOptions (Object)

Describes a block export, i.e. how single node should be exported on an external interface.

Members

type: BlockExportType

Block export type

id: string

A unique identifier for the block export (across all export types)

node-name: string

The node name of the block node to be exported (since: 5.2)

writable: boolean (optional)

True if clients should be able to write to the export (default false)

writethrough: boolean (optional)

If true, caches are flushed after every write request to the export before completion is signalled. (since: 5.2; default: false)

iothread: string (optional)

The name of the iothread object where the export will run. The default is to use the thread currently associated with the block node. (since: 5.2)

fixed-iothread: boolean (optional)

True prevents the block node from being moved to another thread while the export is active. If true and iothread is given, export creation fails if the block node cannot be moved to the iothread. The default is false. (since: 5.2)

The members of BlockExportOptionsNbd when type is "nbd"

The members of BlockExportOptionsVhostUserBlk when type is "vhost-user-blk" (If: CONFIG_VHOST_USER_BLK_SERVER)

The members of BlockExportOptionsFuse when type is "fuse" (If: CONFIG_FUSE)

The members of BlockExportOptionsVduseBlk when type is "vduse-blk" (If: CONFIG_VDUSE_BLK_EXPORT)

Since

4.2

block-export-add (Command)

Creates a new block export.

Arguments

The members of BlockExportOptions

Since

5.2

block-export-del (Command)

Request to remove a block export. This drops the user’s reference to the export, but the export may still stay around after this command returns until the shutdown of the export has completed.

Arguments

id: string

Block export id.

mode: BlockExportRemoveMode (optional)

Mode of command operation. See BlockExportRemoveMode description. Default is ‘safe’.

Errors

• if the export is not found

• if mode is ‘safe’ and the export is still in use (e.g. by existing client connections)

Since

5.2

BLOCK_EXPORT_DELETED (Event)

Emitted when a block export is removed and its id can be reused.

Arguments

id: string

Block export id.

Since

5.2

BlockExportInfo (Object)

Information about a single block export.

Members

id: string

The unique identifier for the block export

type: BlockExportType

The block export type

node-name: string

The node name of the block node that is exported

shutting-down: boolean

True if the export is shutting down (e.g. after a block-export-del command, but before the shutdown has completed)

Since

5.2

query-block-exports (Command)

Returns

A list of BlockExportInfo describing all block exports

Since

5.2

Character devices

ChardevInfo (Object)

Information about a character device.

Members

label: string

the label of the character device

filename: string

the filename of the character device

frontend-open: boolean

shows whether the frontend device attached to this backend (e.g. with the chardev=… option) is in open or closed state (since 2.1)

Note

filename is encoded using the QEMU command line character device encoding. See the QEMU man page for details.

Since

0.14

query-chardev (Command)

Returns information about current character devices.

Returns

a list of ChardevInfo

Since

0.14

Example:

-> { "execute": "query-chardev" }
<- {
      "return": [
         {
            "label": "charchannel0",
            "filename": "unix:/var/lib/libvirt/qemu/seabios.rhel6.agent,server=on",
            "frontend-open": false
         },
         {
            "label": "charmonitor",
            "filename": "unix:/var/lib/libvirt/qemu/seabios.rhel6.monitor,server=on",
            "frontend-open": true
         },
         {
            "label": "charserial0",
            "filename": "pty:/dev/pts/2",
            "frontend-open": true
         }
      ]
   }

ChardevBackendInfo (Object)

Information about a character device backend

Members

name: string

The backend name

Since

2.0

query-chardev-backends (Command)

Returns information about character device backends.

Returns

a list of ChardevBackendInfo

Since

2.0

Example:

-> { "execute": "query-chardev-backends" }
<- {
      "return":[
         {
            "name":"udp"
         },
         {
            "name":"tcp"
         },
         {
            "name":"unix"
         },
         {
            "name":"spiceport"
         }
      ]
   }

DataFormat (Enum)

An enumeration of data format.

Values

utf8

Data is a UTF-8 string (RFC 3629)

base64

Data is Base64 encoded binary (RFC 3548)

Since

1.4

ringbuf-write (Command)

Write to a ring buffer character device.

Arguments

device: string

the ring buffer character device name

data: string

data to write

format: DataFormat (optional)

data encoding (default ‘utf8’).

• base64: data must be base64 encoded text. Its binary decoding gets written.

• utf8: data’s UTF-8 encoding is written

• data itself is always Unicode regardless of format, like any other string.

Since

1.4

Example:

-> { "execute": "ringbuf-write",
     "arguments": { "device": "foo",
                    "data": "abcdefgh",
                    "format": "utf8" } }
<- { "return": {} }

ringbuf-read (Command)

Read from a ring buffer character device.

Arguments

device: string

the ring buffer character device name

size: int

how many bytes to read at most

format: DataFormat (optional)

data encoding (default ‘utf8’).

• base64: the data read is returned in base64 encoding.

• utf8: the data read is interpreted as UTF-8. Bug: can screw up when the buffer contains invalid UTF-8 sequences, NUL characters, after the ring buffer lost data, and when reading stops because the size limit is reached.

• The return value is always Unicode regardless of format, like any other string.

Returns

data read from the device

Since

1.4

Example:

-> { "execute": "ringbuf-read",
     "arguments": { "device": "foo",
                    "size": 1000,
                    "format": "utf8" } }
<- { "return": "abcdefgh" }

ChardevCommon (Object)

Configuration shared across all chardev backends

Members

logfile: string (optional)

The name of a logfile to save output

logappend: boolean (optional)

true to append instead of truncate (default to false to truncate)

Since

2.6

ChardevFile (Object)

Configuration info for file chardevs.

Members

in: string (optional)

The name of the input file

out: string

The name of the output file

append: boolean (optional)

Open the file in append mode (default false to truncate) (Since 2.6)

The members of ChardevCommon

Since

1.4

ChardevHostdev (Object)

Configuration info for device and pipe chardevs.

Members

device: string

The name of the special file for the device, i.e. /dev/ttyS0 on Unix or COM1: on Windows

The members of ChardevCommon

Since

1.4

ChardevSocket (Object)

Configuration info for (stream) socket chardevs.

Members

addr: SocketAddressLegacy

socket address to listen on (server=true) or connect to (server=false)

tls-creds: string (optional)

the ID of the TLS credentials object (since 2.6)

tls-authz: string (optional)

the ID of the QAuthZ authorization object against which the client’s x509 distinguished name will be validated. This object is only resolved at time of use, so can be deleted and recreated on the fly while the chardev server is active. If missing, it will default to denying access (since 4.0)

server: boolean (optional)

create server socket (default: true)

wait: boolean (optional)

wait for incoming connection on server sockets (default: false). Silently ignored with server: false. This use is deprecated.

nodelay: boolean (optional)

set TCP_NODELAY socket option (default: false)

telnet: boolean (optional)

enable telnet protocol on server sockets (default: false)

tn3270: boolean (optional)

enable tn3270 protocol on server sockets (default: false) (Since: 2.10)

websocket: boolean (optional)

enable websocket protocol on server sockets (default: false) (Since: 3.1)

reconnect: int (optional)

For a client socket, if a socket is disconnected, then attempt a reconnect after the given number of seconds. Setting this to zero disables this function. The use of this member is deprecated, use reconnect-ms instead. (default: 0) (Since: 2.2)

reconnect-ms: int (optional)

For a client socket, if a socket is disconnected, then attempt a reconnect after the given number of milliseconds. Setting this to zero disables this function. This member is mutually exclusive with reconnect. (default: 0) (Since: 9.2)

The members of ChardevCommon

Features

deprecated

Member reconnect is deprecated. Use reconnect-ms instead.

Since

1.4

ChardevUdp (Object)

Configuration info for datagram socket chardevs.

Members

remote: SocketAddressLegacy

remote address

local: SocketAddressLegacy (optional)

local address

The members of ChardevCommon

Since

1.5

ChardevMux (Object)

Configuration info for mux chardevs.

Members

chardev: string

name of the base chardev.

The members of ChardevCommon

Since

1.5

ChardevStdio (Object)

Configuration info for stdio chardevs.

Members

signal: boolean (optional)

Allow signals (such as SIGINT triggered by ^C) be delivered to qemu. Default: true.

The members of ChardevCommon

Since

1.5

ChardevSpiceChannel (Object)

Configuration info for spice vm channel chardevs.

Members

type: string

kind of channel (for example vdagent).

The members of ChardevCommon

Since

1.5

If

CONFIG_SPICE

ChardevSpicePort (Object)

Configuration info for spice port chardevs.

Members

fqdn: string

name of the channel (see docs/spice-port-fqdn.txt)

The members of ChardevCommon

Since

1.5

If

CONFIG_SPICE

ChardevDBus (Object)

Configuration info for DBus chardevs.

Members

name: string

name of the channel (following docs/spice-port-fqdn.txt)

The members of ChardevCommon

Since

7.0

If

CONFIG_DBUS_DISPLAY

ChardevVC (Object)

Configuration info for virtual console chardevs.

Members

width: int (optional)

console width, in pixels

height: int (optional)

console height, in pixels

cols: int (optional)

console width, in chars

rows: int (optional)

console height, in chars

The members of ChardevCommon

Note

The options are only effective when the VNC or SDL graphical display backend is active. They are ignored with the GTK, Spice, VNC and D-Bus display backends.

Since

1.5

ChardevRingbuf (Object)

Configuration info for ring buffer chardevs.

Members

size: int (optional)

ring buffer size, must be power of two, default is 65536

The members of ChardevCommon

Since

1.5

ChardevQemuVDAgent (Object)

Configuration info for qemu vdagent implementation.

Members

mouse: boolean (optional)

enable/disable mouse, default is enabled.

clipboard: boolean (optional)

enable/disable clipboard, default is disabled.

The members of ChardevCommon

Since

6.1

If

CONFIG_SPICE_PROTOCOL

ChardevPty (Object)

Configuration info for pty implementation.

Members

path: string (optional)

optional path to create a symbolic link that points to the allocated PTY

The members of ChardevCommon

Since

9.2

ChardevBackendKind (Enum)

Values

file

regular files

serial (If: HAVE_CHARDEV_SERIAL)

serial host device

parallel (If: HAVE_CHARDEV_PARALLEL)

parallel host device

pipe

pipes (since 1.5)

socket

stream socket

udp

datagram socket (since 1.5)

pty

pseudo-terminal

null

provides no input, throws away output

mux

(since 1.5)

msmouse

emulated Microsoft serial mouse (since 1.5)

wctablet

emulated Wacom Penpartner serial tablet (since 2.9)

braille (If: CONFIG_BRLAPI)

Baum Braille device (since 1.5)

testdev

device for test-suite control (since 2.2)

stdio

standard I/O (since 1.5)

console (If: CONFIG_WIN32)

Windows console (since 1.5)

spicevmc (If: CONFIG_SPICE)

spice vm channel (since 1.5)

spiceport (If: CONFIG_SPICE)

Spice port channel (since 1.5)

qemu-vdagent (If: CONFIG_SPICE_PROTOCOL)

Spice vdagent (since 6.1)

dbus (If: CONFIG_DBUS_DISPLAY)

D-Bus channel (since 7.0)

vc

virtual console (since 1.5)

ringbuf

memory ring buffer (since 1.6)

memory

synonym for ringbuf (since 1.5)

Features

deprecated

Member memory is deprecated. Use ringbuf instead.

Since

1.4

ChardevFileWrapper (Object)

Members

data: ChardevFile

Configuration info for file chardevs

Since

1.4

ChardevHostdevWrapper (Object)

Members

data: ChardevHostdev

Configuration info for device and pipe chardevs

Since

1.4

ChardevSocketWrapper (Object)

Members

data: ChardevSocket

Configuration info for (stream) socket chardevs

Since

1.4

ChardevUdpWrapper (Object)

Members

data: ChardevUdp

Configuration info for datagram socket chardevs

Since

1.5

ChardevCommonWrapper (Object)

Members

data: ChardevCommon

Configuration shared across all chardev backends

Since

2.6

ChardevMuxWrapper (Object)

Members

data: ChardevMux

Configuration info for mux chardevs

Since

1.5

ChardevStdioWrapper (Object)

Members

data: ChardevStdio

Configuration info for stdio chardevs

Since

1.5

ChardevSpiceChannelWrapper (Object)

Members

data: ChardevSpiceChannel

Configuration info for spice vm channel chardevs

Since

1.5

If

CONFIG_SPICE

ChardevSpicePortWrapper (Object)

Members

data: ChardevSpicePort

Configuration info for spice port chardevs

Since

1.5

If

CONFIG_SPICE

ChardevQemuVDAgentWrapper (Object)

Members

data: ChardevQemuVDAgent

Configuration info for qemu vdagent implementation

Since

6.1

If

CONFIG_SPICE_PROTOCOL

ChardevDBusWrapper (Object)

Members

data: ChardevDBus

Configuration info for DBus chardevs

Since

7.0

If

CONFIG_DBUS_DISPLAY

ChardevVCWrapper (Object)

Members

data: ChardevVC

Configuration info for virtual console chardevs

Since

1.5

ChardevRingbufWrapper (Object)

Members

data: ChardevRingbuf

Configuration info for ring buffer chardevs

Since

1.5

ChardevPtyWrapper (Object)

Members

data: ChardevPty

Configuration info for pty chardevs

Since

9.2

ChardevBackend (Object)

Configuration info for the new chardev backend.

Members

type: ChardevBackendKind

backend type

The members of ChardevFileWrapper when type is "file"

The members of ChardevHostdevWrapper when type is "serial" (If: HAVE_CHARDEV_SERIAL)

The members of ChardevHostdevWrapper when type is "parallel" (If: HAVE_CHARDEV_PARALLEL)

The members of ChardevHostdevWrapper when type is "pipe"

The members of ChardevSocketWrapper when type is "socket"

The members of ChardevUdpWrapper when type is "udp"

The members of ChardevPtyWrapper when type is "pty"

The members of ChardevCommonWrapper when type is "null"

The members of ChardevMuxWrapper when type is "mux"

The members of ChardevCommonWrapper when type is "msmouse"

The members of ChardevCommonWrapper when type is "wctablet"

The members of ChardevCommonWrapper when type is "braille" (If: CONFIG_BRLAPI)

The members of ChardevCommonWrapper when type is "testdev"

The members of ChardevStdioWrapper when type is "stdio"

The members of ChardevCommonWrapper when type is "console" (If: CONFIG_WIN32)

The members of ChardevSpiceChannelWrapper when type is "spicevmc" (If: CONFIG_SPICE)

The members of ChardevSpicePortWrapper when type is "spiceport" (If: CONFIG_SPICE)

The members of ChardevQemuVDAgentWrapper when type is "qemu-vdagent" (If: CONFIG_SPICE_PROTOCOL)

The members of ChardevDBusWrapper when type is "dbus" (If: CONFIG_DBUS_DISPLAY)

The members of ChardevVCWrapper when type is "vc"

The members of ChardevRingbufWrapper when type is "ringbuf"

The members of ChardevRingbufWrapper when type is "memory"

Since

1.4

ChardevReturn (Object)

Return info about the chardev backend just created.

Members

pty: string (optional)

name of the slave pseudoterminal device, present if and only if a chardev of type ‘pty’ was created

Since

1.4

chardev-add (Command)

Add a character device backend

Arguments

id: string

the chardev’s ID, must be unique

backend: ChardevBackend

backend type and parameters

Returns

ChardevReturn.

Since

1.4

Example:

-> { "execute" : "chardev-add",
     "arguments" : { "id" : "foo",
                     "backend" : { "type" : "null", "data" : {} } } }
<- { "return": {} }

Example:

-> { "execute" : "chardev-add",
     "arguments" : { "id" : "bar",
                     "backend" : { "type" : "file",
                                   "data" : { "out" : "/tmp/bar.log" } } } }
<- { "return": {} }

Example:

-> { "execute" : "chardev-add",
     "arguments" : { "id" : "baz",
                     "backend" : { "type" : "pty", "data" : {} } } }
<- { "return": { "pty" : "/dev/pty/42" } }

chardev-change (Command)

Change a character device backend

Arguments

id: string

the chardev’s ID, must exist

backend: ChardevBackend

new backend type and parameters

Returns

ChardevReturn.

Since

2.10

Example:

-> { "execute" : "chardev-change",
     "arguments" : { "id" : "baz",
                     "backend" : { "type" : "pty", "data" : {} } } }
<- { "return": { "pty" : "/dev/pty/42" } }

Example:

-> {"execute" : "chardev-change",
    "arguments" : {
        "id" : "charchannel2",
        "backend" : {
            "type" : "socket",
            "data" : {
                "addr" : {
                    "type" : "unix" ,
                    "data" : {
                        "path" : "/tmp/charchannel2.socket"
                    }
                 },
                 "server" : true,
                 "wait" : false }}}}
<- {"return": {}}

chardev-remove (Command)

Remove a character device backend

Arguments

id: string

the chardev’s ID, must exist and not be in use

Since

1.4

Example:

-> { "execute": "chardev-remove", "arguments": { "id" : "foo" } }
<- { "return": {} }

chardev-send-break (Command)

Send a break to a character device

Arguments

id: string

the chardev’s ID, must exist

Since

2.10

Example:

-> { "execute": "chardev-send-break", "arguments": { "id" : "foo" } }
<- { "return": {} }

VSERPORT_CHANGE (Event)

Emitted when the guest opens or closes a virtio-serial port.

Arguments

id: string

device identifier of the virtio-serial port

open: boolean

true if the guest has opened the virtio-serial port

Note

This event is rate-limited.

Since

2.1

Example:

<- { "event": "VSERPORT_CHANGE",
     "data": { "id": "channel0", "open": true },
     "timestamp": { "seconds": 1401385907, "microseconds": 422329 } }

Dump guest memory

DumpGuestMemoryFormat (Enum)

An enumeration of guest-memory-dump’s format.

Values

elf

elf format

kdump-zlib

makedumpfile flattened, kdump-compressed format with zlib compression

kdump-lzo

makedumpfile flattened, kdump-compressed format with lzo compression

kdump-snappy

makedumpfile flattened, kdump-compressed format with snappy compression

kdump-raw-zlib

raw assembled kdump-compressed format with zlib compression (since 8.2)

kdump-raw-lzo

raw assembled kdump-compressed format with lzo compression (since 8.2)

kdump-raw-snappy

raw assembled kdump-compressed format with snappy compression (since 8.2)

win-dmp

Windows full crashdump format, can be used instead of ELF converting (since 2.13)

Since

2.0

dump-guest-memory (Command)

Dump guest’s memory to vmcore. It is a synchronous operation that can take very long depending on the amount of guest memory.

Arguments

paging: boolean

if true, do paging to get guest’s memory mapping. This allows using gdb to process the core file.

IMPORTANT: this option can make QEMU allocate several gigabytes of RAM. This can happen for a large guest, or a malicious guest pretending to be large.

Also, paging=true has the following limitations:

1. The guest may be in a catastrophic state or can have corrupted memory, which cannot be trusted

2. The guest can be in real-mode even if paging is enabled. For example, the guest uses ACPI to sleep, and ACPI sleep state goes in real-mode

3. Currently only supported on i386 and x86_64.

protocol: string

the filename or file descriptor of the vmcore. The supported protocols are:

1. file: the protocol starts with “file:”, and the following string is the file’s path.

2. fd: the protocol starts with “fd:”, and the following string is the fd’s name.

detach: boolean (optional)

if true, QMP will return immediately rather than waiting for the dump to finish. The user can track progress using “query-dump”. (since 2.6).

begin: int (optional)

if specified, the starting physical address.

length: int (optional)

if specified, the memory size, in bytes. If you don’t want to dump all guest’s memory, please specify the start begin and length

format: DumpGuestMemoryFormat (optional)

if specified, the format of guest memory dump. But non-elf format is conflict with paging and filter, ie. paging, begin and length is not allowed to be specified with non-elf format at the same time (since 2.0)

Note

All boolean arguments default to false.

Since

1.2

Example:

-> { "execute": "dump-guest-memory",
     "arguments": { "paging": false, "protocol": "fd:dump" } }
<- { "return": {} }

DumpStatus (Enum)

Describe the status of a long-running background guest memory dump.

Values

none

no dump-guest-memory has started yet.

active

there is one dump running in background.

completed

the last dump has finished successfully.

failed

the last dump has failed.

Since

2.6

DumpQueryResult (Object)

The result format for ‘query-dump’.

Members

status: DumpStatus

enum of DumpStatus, which shows current dump status

completed: int

bytes written in latest dump (uncompressed)

total: int

total bytes to be written in latest dump (uncompressed)

Since

2.6

query-dump (Command)

Query latest dump status.

Returns

A DumpStatus object showing the dump status.

Since

2.6

Example:

-> { "execute": "query-dump" }
<- { "return": { "status": "active", "completed": 1024000,
                 "total": 2048000 } }

DUMP_COMPLETED (Event)

Emitted when background dump has completed

Arguments

result: DumpQueryResult

final dump status

error: string (optional)

human-readable error string that provides hint on why dump failed. Only presents on failure. The user should not try to interpret the error string.

Since

2.6

Example:

<- { "event": "DUMP_COMPLETED",
     "data": { "result": { "total": 1090650112, "status": "completed",
                           "completed": 1090650112 } },
     "timestamp": { "seconds": 1648244171, "microseconds": 950316 } }

DumpGuestMemoryCapability (Object)

Members

formats: array of DumpGuestMemoryFormat

the available formats for dump-guest-memory

Since

2.0

query-dump-guest-memory-capability (Command)

Returns the available formats for dump-guest-memory

Returns

A DumpGuestMemoryCapability object listing available formats for dump-guest-memory

Since

2.0

Example:

-> { "execute": "query-dump-guest-memory-capability" }
<- { "return": { "formats":
                 ["elf", "kdump-zlib", "kdump-lzo", "kdump-snappy"] } }

Net devices

set_link (Command)

Sets the link status of a virtual network adapter.

Arguments

name: string

the device name of the virtual network adapter

up: boolean

true to set the link status to be up

Errors

• If name is not a valid network device, DeviceNotFound

Since

0.14

Note

Not all network adapters support setting link status. This command will succeed even if the network adapter does not support link status notification.

Example:

-> { "execute": "set_link",
     "arguments": { "name": "e1000.0", "up": false } }
<- { "return": {} }

netdev_add (Command)

Add a network backend.

Additional arguments depend on the type.

Arguments

The members of Netdev

Since

0.14

Errors

• If type is not a valid network backend, DeviceNotFound

Example:

-> { "execute": "netdev_add",
     "arguments": { "type": "user", "id": "netdev1",
                    "dnssearch": [ { "str": "example.org" } ] } }
<- { "return": {} }

netdev_del (Command)

Remove a network backend.

Arguments

id: string

the name of the network backend to remove

Errors

• If id is not a valid network backend, DeviceNotFound

Since

0.14

Example:

-> { "execute": "netdev_del", "arguments": { "id": "netdev1" } }
<- { "return": {} }

NetLegacyNicOptions (Object)

Create a new Network Interface Card.

Members

netdev: string (optional)

id of -netdev to connect to

macaddr: string (optional)

MAC address

model: string (optional)

device model (e1000, rtl8139, virtio etc.)

addr: string (optional)

PCI device address

vectors: int (optional)

number of MSI-x vectors, 0 to disable MSI-X

Since

1.2

String (Object)

A fat type wrapping ‘str’, to be embedded in lists.

Members

str: string

Not documented

Since

1.2

NetdevUserOptions (Object)

Use the user mode network stack which requires no administrator privilege to run.

Members

hostname: string (optional)

client hostname reported by the builtin DHCP server

restrict: boolean (optional)

isolate the guest from the host

ipv4: boolean (optional)

whether to support IPv4, default true for enabled (since 2.6)

ipv6: boolean (optional)

whether to support IPv6, default true for enabled (since 2.6)

ip: string (optional)

legacy parameter, use net= instead

net: string (optional)

IP network address that the guest will see, in the form addr[/netmask] The netmask is optional, and can be either in the form a.b.c.d or as a number of valid top-most bits. Default is 10.0.2.0/24.

host: string (optional)

guest-visible address of the host

tftp: string (optional)

root directory of the built-in TFTP server

bootfile: string (optional)

BOOTP filename, for use with tftp=

dhcpstart: string (optional)

the first of the 16 IPs the built-in DHCP server can assign

dns: string (optional)

guest-visible address of the virtual nameserver

dnssearch: array of String (optional)

list of DNS suffixes to search, passed as DHCP option to the guest

domainname: string (optional)

guest-visible domain name of the virtual nameserver (since 3.0)

ipv6-prefix: string (optional)

IPv6 network prefix (default is fec0::) (since 2.6). The network prefix is given in the usual hexadecimal IPv6 address notation.

ipv6-prefixlen: int (optional)

IPv6 network prefix length (default is 64) (since 2.6)

ipv6-host: string (optional)

guest-visible IPv6 address of the host (since 2.6)

ipv6-dns: string (optional)

guest-visible IPv6 address of the virtual nameserver (since 2.6)

smb: string (optional)

root directory of the built-in SMB server

smbserver: string (optional)

IP address of the built-in SMB server

hostfwd: array of String (optional)

redirect incoming TCP or UDP host connections to guest endpoints

guestfwd: array of String (optional)

forward guest TCP connections

tftp-server-name: string (optional)

RFC2132 “TFTP server name” string (Since 3.1)

Since

1.2

NetdevTapOptions (Object)

Used to configure a host TAP network interface backend.

Members

ifname: string (optional)

interface name

fd: string (optional)

file descriptor of an already opened tap

fds: string (optional)

multiple file descriptors of already opened multiqueue capable tap

script: string (optional)

script to initialize the interface

downscript: string (optional)

script to shut down the interface

br: string (optional)

bridge name (since 2.8)

helper: string (optional)

command to execute to configure bridge

sndbuf: int (optional)

send buffer limit. Understands [TGMKkb] suffixes.

vnet_hdr: boolean (optional)

enable the IFF_VNET_HDR flag on the tap interface

vhost: boolean (optional)

enable vhost-net network accelerator

vhostfd: string (optional)

file descriptor of an already opened vhost net device

vhostfds: string (optional)

file descriptors of multiple already opened vhost net devices

vhostforce: boolean (optional)

vhost on for non-MSIX virtio guests

queues: int (optional)

number of queues to be created for multiqueue capable tap

poll-us: int (optional)

maximum number of microseconds that could be spent on busy polling for tap (since 2.7)

Since

1.2

NetdevSocketOptions (Object)

Socket netdevs are used to establish a network connection to another QEMU virtual machine via a TCP socket.

Members

fd: string (optional)

file descriptor of an already opened socket

listen: string (optional)

port number, and optional hostname, to listen on

connect: string (optional)

port number, and optional hostname, to connect to

mcast: string (optional)

UDP multicast address and port number

localaddr: string (optional)

source address and port for multicast and udp packets

udp: string (optional)

UDP unicast address and port number

Since

1.2

NetdevL2TPv3Options (Object)

Configure an Ethernet over L2TPv3 tunnel.

Members

src: string

source address

dst: string

destination address

srcport: string (optional)

source port - mandatory for udp, optional for ip

dstport: string (optional)

destination port - mandatory for udp, optional for ip

ipv6: boolean (optional)

force the use of ipv6

udp: boolean (optional)

use the udp version of l2tpv3 encapsulation

cookie64: boolean (optional)

use 64 bit cookies

counter: boolean (optional)

have sequence counter

pincounter: boolean (optional)

pin sequence counter to zero - workaround for buggy implementations or networks with packet reorder

txcookie: int (optional)

32 or 64 bit transmit cookie

rxcookie: int (optional)

32 or 64 bit receive cookie

txsession: int

32 bit transmit session

rxsession: int (optional)

32 bit receive session - if not specified set to the same value as transmit

offset: int (optional)

additional offset - allows the insertion of additional application-specific data before the packet payload

Since

2.1

NetdevVdeOptions (Object)

Connect to a vde switch running on the host.

Members

sock: string (optional)

socket path

port: int (optional)

port number

group: string (optional)

group owner of socket

mode: int (optional)

permissions for socket

Since

1.2

NetdevBridgeOptions (Object)

Connect a host TAP network interface to a host bridge device.

Members

br: string (optional)

bridge name

helper: string (optional)

command to execute to configure bridge

Since

1.2

NetdevHubPortOptions (Object)

Connect two or more net clients through a software hub.

Members

hubid: int

hub identifier number

netdev: string (optional)

used to connect hub to a netdev instead of a device (since 2.12)

Since

1.2

NetdevNetmapOptions (Object)

Connect a client to a netmap-enabled NIC or to a VALE switch port

Members

ifname: string

Either the name of an existing network interface supported by netmap, or the name of a VALE port (created on the fly). A VALE port name is in the form ‘valeXXX:YYY’, where XXX and YYY are non-negative integers. XXX identifies a switch and YYY identifies a port of the switch. VALE ports having the same XXX are therefore connected to the same switch.

devname: string (optional)

path of the netmap device (default: ‘/dev/netmap’).

Since

2.0

AFXDPMode (Enum)

Attach mode for a default XDP program

Values

skb

generic mode, no driver support necessary

native

DRV mode, program is attached to a driver, packets are passed to the socket without allocation of skb.

Since

8.2

If

CONFIG_AF_XDP

NetdevAFXDPOptions (Object)

AF_XDP network backend

Members

ifname: string

The name of an existing network interface.

mode: AFXDPMode (optional)

Attach mode for a default XDP program. If not specified, then ‘native’ will be tried first, then ‘skb’.

force-copy: boolean (optional)

Force XDP copy mode even if device supports zero-copy. (default: false)

queues: int (optional)

number of queues to be used for multiqueue interfaces (default: 1).

start-queue: int (optional)

Use queues starting from this queue number (default: 0).

inhibit: boolean (optional)

Don’t load a default XDP program, use one already loaded to the interface (default: false). Requires sock-fds.

sock-fds: string (optional)

A colon (:) separated list of file descriptors for already open but not bound AF_XDP sockets in the queue order. One fd per queue. These descriptors should already be added into XDP socket map for corresponding queues. Requires inhibit.

Since

8.2

If

CONFIG_AF_XDP

NetdevVhostUserOptions (Object)

Vhost-user network backend

Members

chardev: string

name of a unix socket chardev

vhostforce: boolean (optional)

vhost on for non-MSIX virtio guests (default: false).

queues: int (optional)

number of queues to be created for multiqueue vhost-user (default: 1) (Since 2.5)

Since

2.1

NetdevVhostVDPAOptions (Object)

Vhost-vdpa network backend

vDPA device is a device that uses a datapath which complies with the virtio specifications with a vendor specific control path.

Members

vhostdev: string (optional)

path of vhost-vdpa device (default:’/dev/vhost-vdpa-0’)

vhostfd: string (optional)

file descriptor of an already opened vhost vdpa device

queues: int (optional)

number of queues to be created for multiqueue vhost-vdpa (default: 1)

x-svq: boolean (optional)

Start device with (experimental) shadow virtqueue. (Since 7.1) (default: false)

Features

unstable

Member x-svq is experimental.

Since

5.1

NetdevVmnetHostOptions (Object)

vmnet (host mode) network backend.

Allows the vmnet interface to communicate with other vmnet interfaces that are in host mode and also with the host.

Members

start-address: string (optional)

The starting IPv4 address to use for the interface. Must be in the private IP range (RFC 1918). Must be specified along with end-address and subnet-mask. This address is used as the gateway address. The subsequent address up to and including end-address are placed in the DHCP pool.

end-address: string (optional)

The DHCP IPv4 range end address to use for the interface. Must be in the private IP range (RFC 1918). Must be specified along with start-address and subnet-mask.

subnet-mask: string (optional)

The IPv4 subnet mask to use on the interface. Must be specified along with start-address and subnet-mask.

isolated: boolean (optional)

Enable isolation for this interface. Interface isolation ensures that vmnet interface is not able to communicate with any other vmnet interfaces. Only communication with host is allowed. Requires at least macOS Big Sur 11.0.

net-uuid: string (optional)

The identifier (UUID) to uniquely identify the isolated network vmnet interface should be added to. If set, no DHCP service is provided for this interface and network communication is allowed only with other interfaces added to this network identified by the UUID. Requires at least macOS Big Sur 11.0.

Since

7.1

If

CONFIG_VMNET

NetdevVmnetSharedOptions (Object)

vmnet (shared mode) network backend.

Allows traffic originating from the vmnet interface to reach the Internet through a network address translator (NAT). The vmnet interface can communicate with the host and with other shared mode interfaces on the same subnet. If no DHCP settings, subnet mask and IPv6 prefix specified, the interface can communicate with any of other interfaces in shared mode.

Members

start-address: string (optional)

The starting IPv4 address to use for the interface. Must be in the private IP range (RFC 1918). Must be specified along with end-address and subnet-mask. This address is used as the gateway address. The subsequent address up to and including end-address are placed in the DHCP pool.

end-address: string (optional)

The DHCP IPv4 range end address to use for the interface. Must be in the private IP range (RFC 1918). Must be specified along with start-address and subnet-mask.

subnet-mask: string (optional)

The IPv4 subnet mask to use on the interface. Must be specified along with start-address and subnet-mask.

isolated: boolean (optional)

Enable isolation for this interface. Interface isolation ensures that vmnet interface is not able to communicate with any other vmnet interfaces. Only communication with host is allowed. Requires at least macOS Big Sur 11.0.

nat66-prefix: string (optional)

The IPv6 prefix to use into guest network. Must be a unique local address i.e. start with fd00::/8 and have length of 64.

Since

7.1

If

CONFIG_VMNET

NetdevVmnetBridgedOptions (Object)

vmnet (bridged mode) network backend.

Bridges the vmnet interface with a physical network interface.

Members

ifname: string

The name of the physical interface to be bridged.

isolated: boolean (optional)

Enable isolation for this interface. Interface isolation ensures that vmnet interface is not able to communicate with any other vmnet interfaces. Only communication with host is allowed. Requires at least macOS Big Sur 11.0.

Since

7.1

If

CONFIG_VMNET

NetdevStreamOptions (Object)

Configuration info for stream socket netdev

Members

addr: SocketAddress

socket address to listen on (server=true) or connect to (server=false)

server: boolean (optional)

create server socket (default: false)

reconnect: int (optional)

For a client socket, if a socket is disconnected, then attempt a reconnect after the given number of seconds. Setting this to zero disables this function. (default: 0) (since 8.0)

reconnect-ms: int (optional)

For a client socket, if a socket is disconnected, then attempt a reconnect after the given number of milliseconds. Setting this to zero disables this function. This member is mutually exclusive with reconnect. (default: 0) (Since: 9.2)

Features

deprecated

Member reconnect is deprecated. Use reconnect-ms instead.

Only SocketAddress types ‘unix’, ‘inet’ and ‘fd’ are supported.

Since

7.2

NetdevDgramOptions (Object)

Configuration info for datagram socket netdev.

Members

remote: SocketAddress (optional)

remote address

local: SocketAddress (optional)

local address

Only SocketAddress types ‘unix’, ‘inet’ and ‘fd’ are supported.

If remote address is present and it’s a multicast address, local address is optional. Otherwise local address is required and remote address is optional.

Valid parameters combination table

remote	local	okay?
absent	absent	no
absent	not fd	no
absent	fd	yes
multicast	absent	yes
multicast	present	yes
not multicast	absent	no
not multicast	present	yes

Since

7.2

NetClientDriver (Enum)

Available netdev drivers.

Values

l2tpv3

since 2.1

vhost-vdpa

since 5.1

vmnet-host (If: CONFIG_VMNET)

since 7.1

vmnet-shared (If: CONFIG_VMNET)

since 7.1

vmnet-bridged (If: CONFIG_VMNET)

since 7.1

stream

since 7.2

dgram

since 7.2

af-xdp (If: CONFIG_AF_XDP)

since 8.2

none

Not documented

nic

Not documented

user

Not documented

tap

Not documented

socket

Not documented

vde

Not documented

bridge

Not documented

hubport

Not documented

netmap

Not documented

vhost-user

Not documented

Since

2.7

Netdev (Object)

Captures the configuration of a network device.

Members

id: string

identifier for monitor commands.

type: NetClientDriver

Specify the driver used for interpreting remaining arguments.

The members of NetLegacyNicOptions when type is "nic"

The members of NetdevUserOptions when type is "user"

The members of NetdevTapOptions when type is "tap"

The members of NetdevL2TPv3Options when type is "l2tpv3"

The members of NetdevSocketOptions when type is "socket"

The members of NetdevStreamOptions when type is "stream"

The members of NetdevDgramOptions when type is "dgram"

The members of NetdevVdeOptions when type is "vde"

The members of NetdevBridgeOptions when type is "bridge"

The members of NetdevHubPortOptions when type is "hubport"

The members of NetdevNetmapOptions when type is "netmap"

The members of NetdevAFXDPOptions when type is "af-xdp" (If: CONFIG_AF_XDP)

The members of NetdevVhostUserOptions when type is "vhost-user"

The members of NetdevVhostVDPAOptions when type is "vhost-vdpa"

The members of NetdevVmnetHostOptions when type is "vmnet-host" (If: CONFIG_VMNET)

The members of NetdevVmnetSharedOptions when type is "vmnet-shared" (If: CONFIG_VMNET)

The members of NetdevVmnetBridgedOptions when type is "vmnet-bridged" (If: CONFIG_VMNET)

Since

1.2

RxState (Enum)

Packets receiving state

Values

normal

filter assigned packets according to the mac-table

none

don’t receive any assigned packet

all

receive all assigned packets

Since

1.6

RxFilterInfo (Object)

Rx-filter information for a NIC.

Members

name: string

net client name

promiscuous: boolean

whether promiscuous mode is enabled

multicast: RxState

multicast receive state

unicast: RxState

unicast receive state

vlan: RxState

vlan receive state (Since 2.0)

broadcast-allowed: boolean

whether to receive broadcast

multicast-overflow: boolean

multicast table is overflowed or not

unicast-overflow: boolean

unicast table is overflowed or not

main-mac: string

the main macaddr string

vlan-table: array of int

a list of active vlan id

unicast-table: array of string

a list of unicast macaddr string

multicast-table: array of string

a list of multicast macaddr string

Since

1.6

query-rx-filter (Command)

Return rx-filter information for all NICs (or for the given NIC).

Arguments

name: string (optional)

net client name

Returns

list of RxFilterInfo for all NICs (or for the given NIC).

Errors

• if the given name doesn’t exist

• if the given NIC doesn’t support rx-filter querying

• if the given net client isn’t a NIC

Since

1.6

Example:

-> { "execute": "query-rx-filter", "arguments": { "name": "vnet0" } }
<- { "return": [
        {
            "promiscuous": true,
            "name": "vnet0",
            "main-mac": "52:54:00:12:34:56",
            "unicast": "normal",
            "vlan": "normal",
            "vlan-table": [
                4,
                0
            ],
            "unicast-table": [
            ],
            "multicast": "normal",
            "multicast-overflow": false,
            "unicast-overflow": false,
            "multicast-table": [
                "01:00:5e:00:00:01",
                "33:33:00:00:00:01",
                "33:33:ff:12:34:56"
            ],
            "broadcast-allowed": false
        }
      ]
   }

NIC_RX_FILTER_CHANGED (Event)

Emitted once until the ‘query-rx-filter’ command is executed, the first event will always be emitted

Arguments

name: string (optional)

net client name

path: string

device path

Since

1.6

Example:

<- { "event": "NIC_RX_FILTER_CHANGED",
     "data": { "name": "vnet0",
               "path": "/machine/peripheral/vnet0/virtio-backend" },
     "timestamp": { "seconds": 1368697518, "microseconds": 326866 } }

AnnounceParameters (Object)

Parameters for self-announce timers

Members

initial: int

Initial delay (in ms) before sending the first GARP/RARP announcement

max: int

Maximum delay (in ms) between GARP/RARP announcement packets

rounds: int

Number of self-announcement attempts

step: int

Delay increase (in ms) after each self-announcement attempt

interfaces: array of string (optional)

An optional list of interface names, which restricts the announcement to the listed interfaces. (Since 4.1)

id: string (optional)

A name to be used to identify an instance of announce-timers and to allow it to modified later. Not for use as part of the migration parameters. (Since 4.1)

Since

4.0

announce-self (Command)

Trigger generation of broadcast RARP frames to update network switches. This can be useful when network bonds fail-over the active slave.

Arguments

The members of AnnounceParameters

Example:

-> { "execute": "announce-self",
     "arguments": {
         "initial": 50, "max": 550, "rounds": 10, "step": 50,
         "interfaces": ["vn2", "vn3"], "id": "bob" } }
<- { "return": {} }

Since

4.0

FAILOVER_NEGOTIATED (Event)

Emitted when VIRTIO_NET_F_STANDBY was enabled during feature negotiation. Failover primary devices which were hidden (not hotplugged when requested) before will now be hotplugged by the virtio-net standby device.

Arguments

device-id: string

QEMU device id of the unplugged device

Since

4.2

Example:

<- { "event": "FAILOVER_NEGOTIATED",
     "data": { "device-id": "net1" },
     "timestamp": { "seconds": 1368697518, "microseconds": 326866 } }

NETDEV_STREAM_CONNECTED (Event)

Emitted when the netdev stream backend is connected

Arguments

netdev-id: string

QEMU netdev id that is connected

addr: SocketAddress

The destination address

Since

7.2

Example:

<- { "event": "NETDEV_STREAM_CONNECTED",
     "data": { "netdev-id": "netdev0",
               "addr": { "port": "47666", "ipv6": true,
                         "host": "::1", "type": "inet" } },
     "timestamp": { "seconds": 1666269863, "microseconds": 311222 } }

Example:

<- { "event": "NETDEV_STREAM_CONNECTED",
     "data": { "netdev-id": "netdev0",
               "addr": { "path": "/tmp/qemu0", "type": "unix" } },
     "timestamp": { "seconds": 1666269706, "microseconds": 413651 } }

NETDEV_STREAM_DISCONNECTED (Event)

Emitted when the netdev stream backend is disconnected

Arguments

netdev-id: string

QEMU netdev id that is disconnected

Since

7.2

Example:

<- { "event": "NETDEV_STREAM_DISCONNECTED",
     "data": {"netdev-id": "netdev0"},
     "timestamp": {"seconds": 1663330937, "microseconds": 526695} }

eBPF Objects

eBPF object is an ELF binary that contains the eBPF program and eBPF map description(BTF). Overall, eBPF object should contain the program and enough metadata to create/load eBPF with libbpf. As the eBPF maps/program should correspond to QEMU, the eBPF can’t be used from different QEMU build.

Currently, there is a possible eBPF for receive-side scaling (RSS).

EbpfObject (Object)

An eBPF ELF object.

Members

object: string

the eBPF object encoded in base64

Since

9.0

If

CONFIG_EBPF

EbpfProgramID (Enum)

The eBPF programs that can be gotten with request-ebpf.

Values

rss

Receive side scaling, technology that allows steering traffic between queues by calculation hash. Users may set up indirection table and hash/packet types configurations. Used with virtio-net.

Since

9.0

If

CONFIG_EBPF

request-ebpf (Command)

Retrieve an eBPF object that can be loaded with libbpf. Management applications (e.g. libvirt) may load it and pass file descriptors to QEMU, so they can run running QEMU without BPF capabilities.

Arguments

id: EbpfProgramID

The ID of the program to return.

Returns

eBPF object encoded in base64.

Since

9.0

If

CONFIG_EBPF

Rocker switch device

RockerSwitch (Object)

Rocker switch information.

Members

name: string

switch name

id: int

switch ID

ports: int

number of front-panel ports

Since

2.4

query-rocker (Command)

Return rocker switch information.

Arguments

name: string

switch name

Returns

Rocker information

Since

2.4

Example:

-> { "execute": "query-rocker", "arguments": { "name": "sw1" } }
<- { "return": {"name": "sw1", "ports": 2, "id": 1327446905938}}

RockerPortDuplex (Enum)

An enumeration of port duplex states.

Values

half

half duplex

full

full duplex

Since

2.4

RockerPortAutoneg (Enum)

An enumeration of port autoneg states.

Values

off

autoneg is off

on

autoneg is on

Since

2.4

RockerPort (Object)

Rocker switch port information.

Members

name: string

port name

enabled: boolean

port is enabled for I/O

link-up: boolean

physical link is UP on port

speed: int

port link speed in Mbps

duplex: RockerPortDuplex

port link duplex

autoneg: RockerPortAutoneg

port link autoneg

Since

2.4

query-rocker-ports (Command)

Return rocker switch port information.

Arguments

name: string

port name

Returns

a list of RockerPort information

Since

2.4

Example:

-> { "execute": "query-rocker-ports", "arguments": { "name": "sw1" } }
<- { "return": [ {"duplex": "full", "enabled": true, "name": "sw1.1",
                  "autoneg": "off", "link-up": true, "speed": 10000},
                 {"duplex": "full", "enabled": true, "name": "sw1.2",
                  "autoneg": "off", "link-up": true, "speed": 10000}
   ]}

RockerOfDpaFlowKey (Object)

Rocker switch OF-DPA flow key

Members

priority: int

key priority, 0 being lowest priority

tbl-id: int

flow table ID

in-pport: int (optional)

physical input port

tunnel-id: int (optional)

tunnel ID

vlan-id: int (optional)

VLAN ID

eth-type: int (optional)

Ethernet header type

eth-src: string (optional)

Ethernet header source MAC address

eth-dst: string (optional)

Ethernet header destination MAC address

ip-proto: int (optional)

IP Header protocol field

ip-tos: int (optional)

IP header TOS field

ip-dst: string (optional)

IP header destination address

Note

Optional members may or may not appear in the flow key depending if they’re relevant to the flow key.

Since

2.4

RockerOfDpaFlowMask (Object)

Rocker switch OF-DPA flow mask

Members

in-pport: int (optional)

physical input port

tunnel-id: int (optional)

tunnel ID

vlan-id: int (optional)

VLAN ID

eth-src: string (optional)

Ethernet header source MAC address

eth-dst: string (optional)

Ethernet header destination MAC address

ip-proto: int (optional)

IP Header protocol field

ip-tos: int (optional)

IP header TOS field

Note

Optional members may or may not appear in the flow mask depending if they’re relevant to the flow mask.

Since

2.4

RockerOfDpaFlowAction (Object)

Rocker switch OF-DPA flow action

Members

goto-tbl: int (optional)

next table ID

group-id: int (optional)

group ID

tunnel-lport: int (optional)

tunnel logical port ID

vlan-id: int (optional)

VLAN ID

new-vlan-id: int (optional)

new VLAN ID

out-pport: int (optional)

physical output port

Note

Optional members may or may not appear in the flow action depending if they’re relevant to the flow action.

Since

2.4

RockerOfDpaFlow (Object)

Rocker switch OF-DPA flow

Members

cookie: int

flow unique cookie ID

hits: int

count of matches (hits) on flow

key: RockerOfDpaFlowKey

flow key

mask: RockerOfDpaFlowMask

flow mask

action: RockerOfDpaFlowAction

flow action

Since

2.4

query-rocker-of-dpa-flows (Command)

Return rocker OF-DPA flow information.

Arguments

name: string

switch name

tbl-id: int (optional)

flow table ID. If tbl-id is not specified, returns flow information for all tables.

Returns

rocker OF-DPA flow information

Since

2.4

Example:

-> { "execute": "query-rocker-of-dpa-flows",
     "arguments": { "name": "sw1" } }
<- { "return": [ {"key": {"in-pport": 0, "priority": 1, "tbl-id": 0},
                  "hits": 138,
                  "cookie": 0,
                  "action": {"goto-tbl": 10},
                  "mask": {"in-pport": 4294901760}
                 },
                 {...},
   ]}

RockerOfDpaGroup (Object)

Rocker switch OF-DPA group

Members

id: int

group unique ID

type: int

group type

vlan-id: int (optional)

VLAN ID

pport: int (optional)

physical port number

index: int (optional)

group index, unique with group type

out-pport: int (optional)

output physical port number

group-id: int (optional)

next group ID

set-vlan-id: int (optional)

VLAN ID to set

pop-vlan: int (optional)

pop VLAN headr from packet

group-ids: array of int (optional)

list of next group IDs

set-eth-src: string (optional)

set source MAC address in Ethernet header

set-eth-dst: string (optional)

set destination MAC address in Ethernet header

ttl-check: int (optional)

perform TTL check

Note

Optional members may or may not appear in the group depending if they’re relevant to the group type.

Since

2.4

query-rocker-of-dpa-groups (Command)

Return rocker OF-DPA group information.

Arguments

name: string

switch name

type: int (optional)

group type. If type is not specified, returns group information for all group types.

Returns

rocker OF-DPA group information

Since

2.4

Example:

-> { "execute": "query-rocker-of-dpa-groups",
     "arguments": { "name": "sw1" } }
<- { "return": [ {"type": 0, "out-pport": 2,
                  "pport": 2, "vlan-id": 3841,
                  "pop-vlan": 1, "id": 251723778},
                 {"type": 0, "out-pport": 0,
                  "pport": 0, "vlan-id": 3841,
                  "pop-vlan": 1, "id": 251723776},
                 {"type": 0, "out-pport": 1,
                  "pport": 1, "vlan-id": 3840,
                  "pop-vlan": 1, "id": 251658241},
                 {"type": 0, "out-pport": 0,
                  "pport": 0, "vlan-id": 3840,
                  "pop-vlan": 1, "id": 251658240}
   ]}

TPM (trusted platform module) devices

TpmModel (Enum)

An enumeration of TPM models

Values

tpm-tis

TPM TIS model

tpm-crb

TPM CRB model (since 2.12)

tpm-spapr

TPM SPAPR model (since 5.0)

Since

1.5

If

CONFIG_TPM

query-tpm-models (Command)

Return a list of supported TPM models

Returns

a list of TpmModel

Since

1.5

Example:

-> { "execute": "query-tpm-models" }
<- { "return": [ "tpm-tis", "tpm-crb", "tpm-spapr" ] }

If

CONFIG_TPM

TpmType (Enum)

An enumeration of TPM types

Values

passthrough

TPM passthrough type

emulator

Software Emulator TPM type (since 2.11)

Since

1.5

If

CONFIG_TPM

query-tpm-types (Command)

Return a list of supported TPM types

Returns

a list of TpmType

Since

1.5

Example:

-> { "execute": "query-tpm-types" }
<- { "return": [ "passthrough", "emulator" ] }

If

CONFIG_TPM

TPMPassthroughOptions (Object)

Information about the TPM passthrough type

Members

path: string (optional)

string describing the path used for accessing the TPM device

cancel-path: string (optional)

string showing the TPM’s sysfs cancel file for cancellation of TPM commands while they are executing

Since

1.5

If

CONFIG_TPM

TPMEmulatorOptions (Object)

Information about the TPM emulator type

Members

chardev: string

Name of a unix socket chardev

Since

2.11

If

CONFIG_TPM

TPMPassthroughOptionsWrapper (Object)

Members

data: TPMPassthroughOptions

Information about the TPM passthrough type

Since

1.5

If

CONFIG_TPM

TPMEmulatorOptionsWrapper (Object)

Members

data: TPMEmulatorOptions

Information about the TPM emulator type

Since

2.11

If

CONFIG_TPM

TpmTypeOptions (Object)

A union referencing different TPM backend types’ configuration options

Members

type: TpmType

• ‘passthrough’ The configuration options for the TPM passthrough type

• ‘emulator’ The configuration options for TPM emulator backend type

The members of TPMPassthroughOptionsWrapper when type is "passthrough"

The members of TPMEmulatorOptionsWrapper when type is "emulator"

Since

1.5

If

CONFIG_TPM

TPMInfo (Object)

Information about the TPM

Members

id: string

The Id of the TPM

model: TpmModel

The TPM frontend model

options: TpmTypeOptions

The TPM (backend) type configuration options

Since

1.5

If

CONFIG_TPM

query-tpm (Command)

Return information about the TPM device

Since

1.5

Example:

-> { "execute": "query-tpm" }
<- { "return":
     [
       { "model": "tpm-tis",
         "options":
           { "type": "passthrough",
             "data":
               { "cancel-path": "/sys/class/misc/tpm0/device/cancel",
                 "path": "/dev/tpm0"
               }
           },
         "id": "tpm0"
       }
     ]
   }

If

CONFIG_TPM

Remote desktop

DisplayProtocol (Enum)

Display protocols which support changing password options.

Values

vnc

Not documented

spice

Not documented

Since

7.0

SetPasswordAction (Enum)

An action to take on changing a password on a connection with active clients.

Values

keep

maintain existing clients

fail

fail the command if clients are connected

disconnect

disconnect existing clients

Since

7.0

SetPasswordOptions (Object)

Options for set_password.

Members

protocol: DisplayProtocol

• ‘vnc’ to modify the VNC server password

• ‘spice’ to modify the Spice server password

password: string

the new password

connected: SetPasswordAction (optional)

How to handle existing clients when changing the password. If nothing is specified, defaults to ‘keep’. For VNC, only ‘keep’ is currently implemented.

The members of SetPasswordOptionsVnc when protocol is "vnc"

Since

7.0

SetPasswordOptionsVnc (Object)

Options for set_password specific to the VNC protocol.

Members

display: string (optional)

The id of the display where the password should be changed. Defaults to the first.

Since

7.0

set_password (Command)

Set the password of a remote display server.

Arguments

The members of SetPasswordOptions

Errors

• If Spice is not enabled, DeviceNotFound

Since

0.14

Example:

-> { "execute": "set_password", "arguments": { "protocol": "vnc",
                                               "password": "secret" } }
<- { "return": {} }

ExpirePasswordOptions (Object)

General options for expire_password.

Members

protocol: DisplayProtocol

• ‘vnc’ to modify the VNC server expiration

• ‘spice’ to modify the Spice server expiration

time: string

when to expire the password.

• ‘now’ to expire the password immediately

• ‘never’ to cancel password expiration

• ‘+INT’ where INT is the number of seconds from now (integer)

• ‘INT’ where INT is the absolute time in seconds

The members of ExpirePasswordOptionsVnc when protocol is "vnc"

Note

Time is relative to the server and currently there is no way to coordinate server time with client time. It is not recommended to use the absolute time version of the time parameter unless you’re sure you are on the same machine as the QEMU instance.

Since

7.0

ExpirePasswordOptionsVnc (Object)

Options for expire_password specific to the VNC protocol.

Members

display: string (optional)

The id of the display where the expiration should be changed. Defaults to the first.

Since

7.0

expire_password (Command)

Expire the password of a remote display server.

Arguments

The members of ExpirePasswordOptions

Errors

• If protocol is ‘spice’ and Spice is not active, DeviceNotFound

Since

0.14

Example:

-> { "execute": "expire_password", "arguments": { "protocol": "vnc",
                                                  "time": "+60" } }
<- { "return": {} }

ImageFormat (Enum)

Supported image format types.

Values

png

PNG format

ppm

PPM format

Since

7.1

screendump (Command)

Capture the contents of a screen and write it to a file.

Arguments

filename: string

the path of a new file to store the image

device: string (optional)

ID of the display device that should be dumped. If this parameter is missing, the primary display will be used. (Since 2.12)

head: int (optional)

head to use in case the device supports multiple heads. If this parameter is missing, head #0 will be used. Also note that the head can only be specified in conjunction with the device ID. (Since 2.12)

format: ImageFormat (optional)

image format for screendump. (default: ppm) (Since 7.1)

Since

0.14

Example:

-> { "execute": "screendump",
     "arguments": { "filename": "/tmp/image" } }
<- { "return": {} }

If

CONFIG_PIXMAN

Spice

SpiceBasicInfo (Object)

The basic information for SPICE network connection

Members

host: string

IP address

port: string

port number

family: NetworkAddressFamily

address family

Since

2.1

If

CONFIG_SPICE

SpiceServerInfo (Object)

Information about a SPICE server

Members

auth: string (optional)

authentication method

The members of SpiceBasicInfo

Since

2.1

If

CONFIG_SPICE

SpiceChannel (Object)

Information about a SPICE client channel.

Members

connection-id: int

SPICE connection id number. All channels with the same id belong to the same SPICE session.

channel-type: int

SPICE channel type number. “1” is the main control channel, filter for this one if you want to track spice sessions only

channel-id: int

SPICE channel ID number. Usually “0”, might be different when multiple channels of the same type exist, such as multiple display channels in a multihead setup

tls: boolean

true if the channel is encrypted, false otherwise.

The members of SpiceBasicInfo

Since

0.14

If

CONFIG_SPICE

SpiceQueryMouseMode (Enum)

An enumeration of Spice mouse states.

Values

client

Mouse cursor position is determined by the client.

server

Mouse cursor position is determined by the server.

unknown

No information is available about mouse mode used by the spice server.

Since

1.1

If

CONFIG_SPICE

SpiceInfo (Object)

Information about the SPICE session.

Members

enabled: boolean

true if the SPICE server is enabled, false otherwise

migrated: boolean

true if the last guest migration completed and spice migration had completed as well, false otherwise (since 1.4)

host: string (optional)

The hostname the SPICE server is bound to. This depends on the name resolution on the host and may be an IP address.

port: int (optional)

The SPICE server’s port number.

compiled-version: string (optional)

SPICE server version.

tls-port: int (optional)

The SPICE server’s TLS port number.

auth: string (optional)

the current authentication type used by the server

• ‘none’ if no authentication is being used

• ‘spice’ uses SASL or direct TLS authentication, depending on command line options

mouse-mode: SpiceQueryMouseMode

The mode in which the mouse cursor is displayed currently. Can be determined by the client or the server, or unknown if spice server doesn’t provide this information. (since: 1.1)

channels: array of SpiceChannel (optional)

a list of SpiceChannel for each active spice channel

Since

0.14

If

CONFIG_SPICE

query-spice (Command)

Returns information about the current SPICE server

Returns

SpiceInfo

Since

0.14

Example:

-> { "execute": "query-spice" }
<- { "return": {
         "enabled": true,
         "auth": "spice",
         "port": 5920,
         "migrated":false,
         "tls-port": 5921,
         "host": "0.0.0.0",
         "mouse-mode":"client",
         "channels": [
            {
               "port": "54924",
               "family": "ipv4",
               "channel-type": 1,
               "connection-id": 1804289383,
               "host": "127.0.0.1",
               "channel-id": 0,
               "tls": true
            },
            {
               "port": "36710",
               "family": "ipv4",
               "channel-type": 4,
               "connection-id": 1804289383,
               "host": "127.0.0.1",
               "channel-id": 0,
               "tls": false
            },
            ...
         ]
      }
   }

If

CONFIG_SPICE

SPICE_CONNECTED (Event)

Emitted when a SPICE client establishes a connection

Arguments

server: SpiceBasicInfo

server information

client: SpiceBasicInfo

client information

Since

0.14

Example:

<- { "timestamp": {"seconds": 1290688046, "microseconds": 388707},
     "event": "SPICE_CONNECTED",
     "data": {
       "server": { "port": "5920", "family": "ipv4", "host": "127.0.0.1"},
       "client": {"port": "52873", "family": "ipv4", "host": "127.0.0.1"}
   }}

If

CONFIG_SPICE

SPICE_INITIALIZED (Event)

Emitted after initial handshake and authentication takes place (if any) and the SPICE channel is up and running

Arguments

server: SpiceServerInfo

server information

client: SpiceChannel

client information

Since

0.14

Example:

<- { "timestamp": {"seconds": 1290688046, "microseconds": 417172},
     "event": "SPICE_INITIALIZED",
     "data": {"server": {"auth": "spice", "port": "5921",
                         "family": "ipv4", "host": "127.0.0.1"},
              "client": {"port": "49004", "family": "ipv4", "channel-type": 3,
                         "connection-id": 1804289383, "host": "127.0.0.1",
                         "channel-id": 0, "tls": true}
   }}

If

CONFIG_SPICE

SPICE_DISCONNECTED (Event)

Emitted when the SPICE connection is closed

Arguments

server: SpiceBasicInfo

server information

client: SpiceBasicInfo

client information

Since

0.14

Example:

<- { "timestamp": {"seconds": 1290688046, "microseconds": 388707},
     "event": "SPICE_DISCONNECTED",
     "data": {
       "server": { "port": "5920", "family": "ipv4", "host": "127.0.0.1"},
       "client": {"port": "52873", "family": "ipv4", "host": "127.0.0.1"}
   }}

If

CONFIG_SPICE

SPICE_MIGRATE_COMPLETED (Event)

Emitted when SPICE migration has completed

Since

1.3

Example:

<- { "timestamp": {"seconds": 1290688046, "microseconds": 417172},
     "event": "SPICE_MIGRATE_COMPLETED" }

If

CONFIG_SPICE

VNC

VncBasicInfo (Object)

The basic information for vnc network connection

Members

host: string

IP address

service: string

The service name of the vnc port. This may depend on the host system’s service database so symbolic names should not be relied on.

family: NetworkAddressFamily

address family

websocket: boolean

true in case the socket is a websocket (since 2.3).

Since

2.1

If

CONFIG_VNC

VncServerInfo (Object)

The network connection information for server

Members

auth: string (optional)

authentication method used for the plain (non-websocket) VNC server

The members of VncBasicInfo

Since

2.1

If

CONFIG_VNC

VncClientInfo (Object)

Information about a connected VNC client.

Members

x509_dname: string (optional)

If x509 authentication is in use, the Distinguished Name of the client.

sasl_username: string (optional)

If SASL authentication is in use, the SASL username used for authentication.

The members of VncBasicInfo

Since

0.14

If

CONFIG_VNC

VncInfo (Object)

Information about the VNC session.

Members

enabled: boolean

true if the VNC server is enabled, false otherwise

host: string (optional)

The hostname the VNC server is bound to. This depends on the name resolution on the host and may be an IP address.

family: NetworkAddressFamily (optional)

• ‘ipv6’ if the host is listening for IPv6 connections

• ‘ipv4’ if the host is listening for IPv4 connections

• ‘unix’ if the host is listening on a unix domain socket

• ‘unknown’ otherwise

service: string (optional)

The service name of the server’s port. This may depends on the host system’s service database so symbolic names should not be relied on.

auth: string (optional)

the current authentication type used by the server

• ‘none’ if no authentication is being used

• ‘vnc’ if VNC authentication is being used

• ‘vencrypt+plain’ if VEncrypt is used with plain text authentication

• ‘vencrypt+tls+none’ if VEncrypt is used with TLS and no authentication

• ‘vencrypt+tls+vnc’ if VEncrypt is used with TLS and VNC authentication

• ‘vencrypt+tls+plain’ if VEncrypt is used with TLS and plain text auth

• ‘vencrypt+x509+none’ if VEncrypt is used with x509 and no auth

• ‘vencrypt+x509+vnc’ if VEncrypt is used with x509 and VNC auth

• ‘vencrypt+x509+plain’ if VEncrypt is used with x509 and plain text auth

• ‘vencrypt+tls+sasl’ if VEncrypt is used with TLS and SASL auth

• ‘vencrypt+x509+sasl’ if VEncrypt is used with x509 and SASL auth

clients: array of VncClientInfo (optional)

a list of VncClientInfo of all currently connected clients

Since

0.14

If

CONFIG_VNC

VncPrimaryAuth (Enum)

vnc primary authentication method.

Values

none

Not documented

vnc

Not documented

ra2

Not documented

ra2ne

Not documented

tight

Not documented

ultra

Not documented

tls

Not documented

vencrypt

Not documented

sasl

Not documented

Since

2.3

If

CONFIG_VNC

VncVencryptSubAuth (Enum)

vnc sub authentication method with vencrypt.

Values

plain

Not documented

tls-none

Not documented

x509-none

Not documented

tls-vnc

Not documented

x509-vnc

Not documented

tls-plain

Not documented

x509-plain

Not documented

tls-sasl

Not documented

x509-sasl

Not documented

Since

2.3

If

CONFIG_VNC

VncServerInfo2 (Object)

The network connection information for server

Members

auth: VncPrimaryAuth

The current authentication type used by the servers

vencrypt: VncVencryptSubAuth (optional)

The vencrypt sub authentication type used by the servers, only specified in case auth == vencrypt.

The members of VncBasicInfo

Since

2.9

If

CONFIG_VNC

VncInfo2 (Object)

Information about a vnc server

Members

id: string

vnc server name.

server: array of VncServerInfo2

A list of VncBasincInfo describing all listening sockets. The list can be empty (in case the vnc server is disabled). It also may have multiple entries: normal + websocket, possibly also ipv4 + ipv6 in the future.

clients: array of VncClientInfo

A list of VncClientInfo of all currently connected clients. The list can be empty, for obvious reasons.

auth: VncPrimaryAuth

The current authentication type used by the non-websockets servers

vencrypt: VncVencryptSubAuth (optional)

The vencrypt authentication type used by the servers, only specified in case auth == vencrypt.

display: string (optional)

The display device the vnc server is linked to.

Since

2.3

If

CONFIG_VNC

query-vnc (Command)

Returns information about the current VNC server

Returns

VncInfo

Since

0.14

Example:

-> { "execute": "query-vnc" }
<- { "return": {
         "enabled":true,
         "host":"0.0.0.0",
         "service":"50402",
         "auth":"vnc",
         "family":"ipv4",
         "clients":[
            {
               "host":"127.0.0.1",
               "service":"50401",
               "family":"ipv4",
               "websocket":false
            }
         ]
      }
   }

If

CONFIG_VNC

query-vnc-servers (Command)

Returns a list of vnc servers. The list can be empty.

Returns

a list of VncInfo2

Since

2.3

If

CONFIG_VNC

change-vnc-password (Command)

Change the VNC server password.

Arguments

password: string

the new password to use with VNC authentication

Since

1.1

Note

An empty password in this command will set the password to the empty string. Existing clients are unaffected by executing this command.

If

CONFIG_VNC

VNC_CONNECTED (Event)

Emitted when a VNC client establishes a connection

Arguments

server: VncServerInfo

server information

client: VncBasicInfo

client information

Note

This event is emitted before any authentication takes place, thus the authentication ID is not provided.

Since

0.13

Example:

<- { "event": "VNC_CONNECTED",
     "data": {
           "server": { "auth": "sasl", "family": "ipv4", "websocket": false,
                       "service": "5901", "host": "0.0.0.0" },
           "client": { "family": "ipv4", "service": "58425",
                       "host": "127.0.0.1", "websocket": false } },
     "timestamp": { "seconds": 1262976601, "microseconds": 975795 } }

If

CONFIG_VNC

VNC_INITIALIZED (Event)

Emitted after authentication takes place (if any) and the VNC session is made active

Arguments

server: VncServerInfo

server information

client: VncClientInfo

client information

Since

0.13

Example:

<-  { "event": "VNC_INITIALIZED",
      "data": {
           "server": { "auth": "sasl", "family": "ipv4", "websocket": false,
                       "service": "5901", "host": "0.0.0.0"},
           "client": { "family": "ipv4", "service": "46089", "websocket": false,
                       "host": "127.0.0.1", "sasl_username": "luiz" } },
      "timestamp": { "seconds": 1263475302, "microseconds": 150772 } }

If

CONFIG_VNC

VNC_DISCONNECTED (Event)

Emitted when the connection is closed

Arguments

server: VncServerInfo

server information

client: VncClientInfo

client information

Since

0.13

Example:

<- { "event": "VNC_DISCONNECTED",
     "data": {
           "server": { "auth": "sasl", "family": "ipv4", "websocket": false,
                       "service": "5901", "host": "0.0.0.0" },
           "client": { "family": "ipv4", "service": "58425", "websocket": false,
                       "host": "127.0.0.1", "sasl_username": "luiz" } },
     "timestamp": { "seconds": 1262976601, "microseconds": 975795 } }

If

CONFIG_VNC

Input

MouseInfo (Object)

Information about a mouse device.

Members

name: string

the name of the mouse device

index: int

the index of the mouse device

current: boolean

true if this device is currently receiving mouse events

absolute: boolean

true if this device supports absolute coordinates as input

Since

0.14

query-mice (Command)

Returns information about each active mouse device

Returns

a list of MouseInfo for each device

Since

0.14

Example:

-> { "execute": "query-mice" }
<- { "return": [
         {
            "name":"QEMU Microsoft Mouse",
            "index":0,
            "current":false,
            "absolute":false
         },
         {
            "name":"QEMU PS/2 Mouse",
            "index":1,
            "current":true,
            "absolute":true
         }
      ]
   }

QKeyCode (Enum)

An enumeration of key name.

This is used by the send-key command.

Values

unmapped

since 2.0

pause

since 2.0

ro

since 2.4

kp_comma

since 2.4

kp_equals

since 2.6

power

since 2.6

hiragana

since 2.9

henkan

since 2.9

yen

since 2.9

sleep

since 2.10

wake

since 2.10

audionext

since 2.10

audioprev

since 2.10

audiostop

since 2.10

audioplay

since 2.10

audiomute

since 2.10

volumeup

since 2.10

volumedown

since 2.10

mediaselect

since 2.10

mail

since 2.10

calculator

since 2.10

computer

since 2.10

ac_home

since 2.10

ac_back

since 2.10

ac_forward

since 2.10

ac_refresh

since 2.10

ac_bookmarks

since 2.10

muhenkan

since 2.12

katakanahiragana

since 2.12

lang1

since 6.1

lang2

since 6.1

f13

since 8.0

f14

since 8.0

f15

since 8.0

f16

since 8.0

f17

since 8.0

f18

since 8.0

f19

since 8.0

f20

since 8.0

f21

since 8.0

f22

since 8.0

f23

since 8.0

f24

since 8.0

shift

Not documented

shift_r

Not documented

alt

Not documented

alt_r

Not documented

ctrl

Not documented

ctrl_r

Not documented

menu

Not documented

esc

Not documented

1

Not documented

2

Not documented

3

Not documented

4

Not documented

5

Not documented

6

Not documented

7

Not documented

8

Not documented

9

Not documented

0

Not documented

minus

Not documented

equal

Not documented

backspace

Not documented

tab

Not documented

q

Not documented

w

Not documented

e

Not documented

r

Not documented

t

Not documented

y

Not documented

u

Not documented

i

Not documented

o

Not documented

p

Not documented

bracket_left

Not documented

bracket_right

Not documented

ret

Not documented

a

Not documented

s

Not documented

d

Not documented

f

Not documented

g

Not documented

h

Not documented

j

Not documented

k

Not documented

l

Not documented

semicolon

Not documented

apostrophe

Not documented

grave_accent

Not documented

backslash

Not documented

z

Not documented

x

Not documented

c

Not documented

v

Not documented

b

Not documented

n

Not documented

m

Not documented

comma

Not documented

dot

Not documented

slash

Not documented

asterisk

Not documented

spc

Not documented

caps_lock

Not documented

f1

Not documented

f2

Not documented

f3

Not documented

f4

Not documented

f5

Not documented

f6

Not documented

f7

Not documented

f8

Not documented

f9

Not documented

f10

Not documented

num_lock

Not documented

scroll_lock

Not documented

kp_divide

Not documented

kp_multiply

Not documented

kp_subtract

Not documented

kp_add

Not documented

kp_enter

Not documented

kp_decimal

Not documented

sysrq

Not documented

kp_0

Not documented

kp_1

Not documented

kp_2

Not documented

kp_3

Not documented

kp_4

Not documented

kp_5

Not documented

kp_6

Not documented

kp_7

Not documented

kp_8

Not documented

kp_9

Not documented

less

Not documented

f11

Not documented

f12

Not documented

print

Not documented

home

Not documented

pgup

Not documented

pgdn

Not documented

end

Not documented

left

Not documented

up

Not documented

down

Not documented

right

Not documented

insert

Not documented

delete

Not documented

stop

Not documented

again

Not documented

props

Not documented

undo

Not documented

front

Not documented

copy

Not documented

open

Not documented

paste

Not documented

find

Not documented

cut

Not documented

lf

Not documented

help

Not documented

meta_l

Not documented

meta_r

Not documented

compose

Not documented

‘sysrq’ was mistakenly added to hack around the fact that the ps2 driver was not generating correct scancodes sequences when ‘alt+print’ was pressed. This flaw is now fixed and the ‘sysrq’ key serves no further purpose. Any further use of ‘sysrq’ will be transparently changed to ‘print’, so they are effectively synonyms.

Since

1.3

KeyValueKind (Enum)

Values

number

Not documented

qcode

Not documented

Since

1.3

IntWrapper (Object)

Members

data: int

a numeric key code

Since

1.3

QKeyCodeWrapper (Object)

Members

data: QKeyCode

An enumeration of key name

Since

1.3

KeyValue (Object)

Represents a keyboard key.

Members

type: KeyValueKind

key encoding

The members of IntWrapper when type is "number"

The members of QKeyCodeWrapper when type is "qcode"

Since

1.3

send-key (Command)

Send keys to guest.

Arguments

keys: array of KeyValue

An array of KeyValue elements. All KeyValues in this array are simultaneously sent to the guest. A KeyValue.number value is sent directly to the guest, while KeyValue.qcode must be a valid QKeyCode value

hold-time: int (optional)

time to delay key up events, milliseconds. Defaults to 100

Errors

• If key is unknown or redundant, GenericError

Since

1.3

Example:

-> { "execute": "send-key",
     "arguments": { "keys": [ { "type": "qcode", "data": "ctrl" },
                              { "type": "qcode", "data": "alt" },
                              { "type": "qcode", "data": "delete" } ] } }
<- { "return": {} }

InputButton (Enum)

Button of a pointer input device (mouse, tablet).

Values

side

front side button of a 5-button mouse (since 2.9)

extra

rear side button of a 5-button mouse (since 2.9)

touch

screen contact on a multi-touch device (since 8.1)

left

Not documented

middle

Not documented

right

Not documented

wheel-up

Not documented

wheel-down

Not documented

wheel-left

Not documented

wheel-right

Not documented

Since

2.0

InputAxis (Enum)

Position axis of a pointer input device (mouse, tablet).

Values

x

Not documented

y

Not documented

Since

2.0

InputMultiTouchType (Enum)

Type of a multi-touch event.

Values

begin

A new touch event sequence has just started.

update

A touch event sequence has been updated.

end

A touch event sequence has finished.

cancel

A touch event sequence has been canceled.

data

Absolute position data.

Since

8.1

InputKeyEvent (Object)

Keyboard input event.

Members

key: KeyValue

Which key this event is for.

down: boolean

True for key-down and false for key-up events.

Since

2.0

InputBtnEvent (Object)

Pointer button input event.

Members

button: InputButton

Which button this event is for.

down: boolean

True for key-down and false for key-up events.

Since

2.0

InputMoveEvent (Object)

Pointer motion input event.

Members

axis: InputAxis

Which axis is referenced by value.

value: int

Pointer position. For absolute coordinates the valid range is 0 -> 0x7ffff

Since

2.0

InputMultiTouchEvent (Object)

MultiTouch input event.

Members

type: InputMultiTouchType

The type of multi-touch event.

slot: int

Which slot has generated the event.

tracking-id: int

ID to correlate this event with previously generated events.

axis: InputAxis

Which axis is referenced by value.

value: int

Contact position.

Since

8.1

InputEventKind (Enum)

Values

key

a keyboard input event

btn

a pointer button input event

rel

a relative pointer motion input event

abs

an absolute pointer motion input event

mtt

a multi-touch input event

Since

2.0

InputKeyEventWrapper (Object)

Members

data: InputKeyEvent

Keyboard input event

Since

2.0

InputBtnEventWrapper (Object)

Members

data: InputBtnEvent

Pointer button input event

Since

2.0

InputMoveEventWrapper (Object)

Members

data: InputMoveEvent

Pointer motion input event

Since

2.0

InputMultiTouchEventWrapper (Object)

Members

data: InputMultiTouchEvent

MultiTouch input event

Since

8.1

InputEvent (Object)

Input event union.

Members

type: InputEventKind

the type of input event

The members of InputKeyEventWrapper when type is "key"

The members of InputBtnEventWrapper when type is "btn"

The members of InputMoveEventWrapper when type is "rel"

The members of InputMoveEventWrapper when type is "abs"

The members of InputMultiTouchEventWrapper when type is "mtt"

Since

2.0

input-send-event (Command)

Send input event(s) to guest.

The device and head parameters can be used to send the input event to specific input devices in case (a) multiple input devices of the same kind are added to the virtual machine and (b) you have configured input routing (see docs/multiseat.txt) for those input devices. The parameters work exactly like the device and head properties of input devices. If device is missing, only devices that have no input routing config are admissible. If device is specified, both input devices with and without input routing config are admissible, but devices with input routing config take precedence.

Arguments

device: string (optional)

display device to send event(s) to.

head: int (optional)

head to send event(s) to, in case the display device supports multiple scanouts.

events: array of InputEvent

List of InputEvent union.

Since

2.6

Note

The consoles are visible in the qom tree, under /backend/console[$index]. They have a device link and head property, so it is possible to map which console belongs to which device and display.

Example: Press left mouse button

 -> { "execute": "input-send-event",
     "arguments": { "device": "video0",
                    "events": [ { "type": "btn",
                    "data" : { "down": true, "button": "left" } } ] } }
 <- { "return": {} }

 -> { "execute": "input-send-event",
     "arguments": { "device": "video0",
                    "events": [ { "type": "btn",
                    "data" : { "down": false, "button": "left" } } ] } }
 <- { "return": {} }

Example: Press ctrl-alt-del

 -> { "execute": "input-send-event",
      "arguments": { "events": [
         { "type": "key", "data" : { "down": true,
           "key": {"type": "qcode", "data": "ctrl" } } },
         { "type": "key", "data" : { "down": true,
           "key": {"type": "qcode", "data": "alt" } } },
         { "type": "key", "data" : { "down": true,
           "key": {"type": "qcode", "data": "delete" } } } ] } }
 <- { "return": {} }

Example: Move mouse pointer to absolute coordinates

 -> { "execute": "input-send-event" ,
   "arguments": { "events": [
                { "type": "abs", "data" : { "axis": "x", "value" : 20000 } },
                { "type": "abs", "data" : { "axis": "y", "value" : 400 } } ] } }
 <- { "return": {} }

DisplayGTK (Object)

GTK display options.

Members

grab-on-hover: boolean (optional)

Grab keyboard input on mouse hover.

zoom-to-fit: boolean (optional)

Zoom guest display to fit into the host window. When turned off the host window will be resized instead. In case the display device can notify the guest on window resizes (virtio-gpu) this will default to “on”, assuming the guest will resize the display to match the window size then. Otherwise it defaults to “off”. (Since 3.1)

show-tabs: boolean (optional)

Display the tab bar for switching between the various graphical interfaces (e.g. VGA and virtual console character devices) by default. (Since 7.1)

show-menubar: boolean (optional)

Display the main window menubar. Defaults to “on”. (Since 8.0)

Since

2.12

DisplayEGLHeadless (Object)

EGL headless display options.

Members

rendernode: string (optional)

Which DRM render node should be used. Default is the first available node on the host.

Since

3.1

DisplayDBus (Object)

DBus display options.

Members

addr: string (optional)

The D-Bus bus address (default to the session bus).

rendernode: string (optional)

Which DRM render node should be used. Default is the first available node on the host.

p2p: boolean (optional)

Whether to use peer-to-peer connections (accepted through add_client).

audiodev: string (optional)

Use the specified DBus audiodev to export audio.

Since

7.0

DisplayGLMode (Enum)

Display OpenGL mode.

Values

off

Disable OpenGL (default).

on

Use OpenGL, pick context type automatically. Would better be named ‘auto’ but is called ‘on’ for backward compatibility with bool type.

core

Use OpenGL with Core (desktop) Context.

es

Use OpenGL with ES (embedded systems) Context.

Since

3.0

DisplayCurses (Object)

Curses display options.

Members

charset: string (optional)

Font charset used by guest (default: CP437).

Since

4.0

DisplayCocoa (Object)

Cocoa display options.

Members

left-command-key: boolean (optional)

Enable/disable forwarding of left command key to guest. Allows command-tab window switching on the host without sending this key to the guest when “off”. Defaults to “on”

full-grab: boolean (optional)

Capture all key presses, including system combos. This requires accessibility permissions, since it performs a global grab on key events. (default: off) See https://support.apple.com/en-in/guide/mac-help/mh32356/mac

swap-opt-cmd: boolean (optional)

Swap the Option and Command keys so that their key codes match their position on non-Mac keyboards and you can use Meta/Super and Alt where you expect them. (default: off)

zoom-to-fit: boolean (optional)

Zoom guest display to fit into the host window. When turned off the host window will be resized instead. Defaults to “off”. (Since 8.2)

zoom-interpolation: boolean (optional)

Apply interpolation to smooth output when zoom-to-fit is enabled. Defaults to “off”. (Since 9.0)

Since

7.0

HotKeyMod (Enum)

Set of modifier keys that need to be held for shortcut key actions.

Values

lctrl-lalt

Not documented

lshift-lctrl-lalt

Not documented

rctrl

Not documented

Since

7.1

DisplaySDL (Object)

SDL2 display options.

Members

grab-mod: HotKeyMod (optional)

Modifier keys that should be pressed together with the “G” key to release the mouse grab.

Since

7.1

DisplayType (Enum)

Display (user interface) type.

Values

default

The default user interface, selecting from the first available of gtk, sdl, cocoa, and vnc.

none

No user interface or video output display. The guest will still see an emulated graphics card, but its output will not be displayed to the QEMU user.

gtk (If: CONFIG_GTK)

The GTK user interface.

sdl (If: CONFIG_SDL)

The SDL user interface.

egl-headless (If: CONFIG_OPENGL)

No user interface, offload GL operations to a local DRI device. Graphical display need to be paired with VNC or Spice. (Since 3.1)

curses (If: CONFIG_CURSES)

Display video output via curses. For graphics device models which support a text mode, QEMU can display this output using a curses/ncurses interface. Nothing is displayed when the graphics device is in graphical mode or if the graphics device does not support a text mode. Generally only the VGA device models support text mode.

cocoa (If: CONFIG_COCOA)

The Cocoa user interface.

spice-app (If: CONFIG_SPICE)

Set up a Spice server and run the default associated application to connect to it. The server will redirect the serial console and QEMU monitors. (Since 4.0)

dbus (If: CONFIG_DBUS_DISPLAY)

Start a D-Bus service for the display. (Since 7.0)

Since

2.12

DisplayOptions (Object)

Display (user interface) options.

Members

type: DisplayType

Which DisplayType qemu should use.

full-screen: boolean (optional)

Start user interface in fullscreen mode (default: off).

window-close: boolean (optional)

Allow to quit qemu with window close button (default: on).

show-cursor: boolean (optional)

Force showing the mouse cursor (default: off). (since: 5.0)

gl: DisplayGLMode (optional)

Enable OpenGL support (default: off).

The members of DisplayGTK when type is "gtk" (If: CONFIG_GTK)

The members of DisplayCocoa when type is "cocoa" (If: CONFIG_COCOA)

The members of DisplayCurses when type is "curses" (If: CONFIG_CURSES)

The members of DisplayEGLHeadless when type is "egl-headless" (If: CONFIG_OPENGL)

The members of DisplayDBus when type is "dbus" (If: CONFIG_DBUS_DISPLAY)

The members of DisplaySDL when type is "sdl" (If: CONFIG_SDL)

Since

2.12

query-display-options (Command)

Returns information about display configuration

Returns

DisplayOptions

Since

3.1

DisplayReloadType (Enum)

Available DisplayReload types.

Values

vnc

VNC display

Since

6.0

DisplayReloadOptionsVNC (Object)

Specify the VNC reload options.

Members

tls-certs: boolean (optional)

reload tls certs or not.

Since

6.0

DisplayReloadOptions (Object)

Options of the display configuration reload.

Members

type: DisplayReloadType

Specify the display type.

The members of DisplayReloadOptionsVNC when type is "vnc"

Since

6.0

display-reload (Command)

Reload display configuration.

Arguments

The members of DisplayReloadOptions

Since

6.0

Example:

-> { "execute": "display-reload",
     "arguments": { "type": "vnc", "tls-certs": true  } }
<- { "return": {} }

DisplayUpdateType (Enum)

Available DisplayUpdate types.

Values

vnc

VNC display

Since

7.1

DisplayUpdateOptionsVNC (Object)

Specify the VNC reload options.

Members

addresses: array of SocketAddress (optional)

If specified, change set of addresses to listen for connections. Addresses configured for websockets are not touched.

Since

7.1

DisplayUpdateOptions (Object)

Options of the display configuration reload.

Members

type: DisplayUpdateType

Specify the display type.

The members of DisplayUpdateOptionsVNC when type is "vnc"

Since

7.1

display-update (Command)

Update display configuration.

Arguments

The members of DisplayUpdateOptions

Since

7.1

Example:

-> { "execute": "display-update",
     "arguments": { "type": "vnc", "addresses":
                    [ { "type": "inet", "host": "0.0.0.0",
                        "port": "5901" } ] } }
<- { "return": {} }

client_migrate_info (Command)

Set migration information for remote display. This makes the server ask the client to automatically reconnect using the new parameters once migration finished successfully. Only implemented for SPICE.

Arguments

protocol: string

must be “spice”

hostname: string

migration target hostname

port: int (optional)

spice tcp port for plaintext channels

tls-port: int (optional)

spice tcp port for tls-secured channels

cert-subject: string (optional)

server certificate subject

Since

0.14

Example:

-> { "execute": "client_migrate_info",
     "arguments": { "protocol": "spice",
                    "hostname": "virt42.lab.kraxel.org",
                    "port": 1234 } }
<- { "return": {} }

User authorization

QAuthZListPolicy (Enum)

The authorization policy result

Values

deny

deny access

allow

allow access

Since

4.0

QAuthZListFormat (Enum)

The authorization policy match format

Values

exact

an exact string match

glob

string with ? and * shell wildcard support

Since

4.0

QAuthZListRule (Object)

A single authorization rule.

Members

match: string

a string or glob to match against a user identity

policy: QAuthZListPolicy

the result to return if match evaluates to true

format: QAuthZListFormat (optional)

the format of the match rule (default ‘exact’)

Since

4.0

AuthZListProperties (Object)

Properties for authz-list objects.

Members

policy: QAuthZListPolicy (optional)

Default policy to apply when no rule matches (default: deny)

rules: array of QAuthZListRule (optional)

Authorization rules based on matching user

Since

4.0

AuthZListFileProperties (Object)

Properties for authz-listfile objects.

Members

filename: string

File name to load the configuration from. The file must contain valid JSON for AuthZListProperties.

refresh: boolean (optional)

If true, inotify is used to monitor the file, automatically reloading changes. If an error occurs during reloading, all authorizations will fail until the file is next successfully loaded. (default: true if the binary was built with CONFIG_INOTIFY1, false otherwise)

Since

4.0

AuthZPAMProperties (Object)

Properties for authz-pam objects.

Members

service: string

PAM service name to use for authorization

Since

4.0

AuthZSimpleProperties (Object)

Properties for authz-simple objects.

Members

identity: string

Identifies the allowed user. Its format depends on the network service that authorization object is associated with. For authorizing based on TLS x509 certificates, the identity must be the x509 distinguished name.

Since

4.0

Migration

MigrationStats (Object)

Detailed migration status.

Members

transferred: int

amount of bytes already transferred to the target VM

remaining: int

amount of bytes remaining to be transferred to the target VM

total: int

total amount of bytes involved in the migration process

duplicate: int

number of duplicate (zero) pages (since 1.2)

normal: int

number of normal pages (since 1.2)

normal-bytes: int

number of normal bytes sent (since 1.2)

dirty-pages-rate: int

number of pages dirtied by second by the guest (since 1.3)

mbps: number

throughput in megabits/sec. (since 1.6)

dirty-sync-count: int

number of times that dirty ram was synchronized (since 2.1)

postcopy-requests: int

The number of page requests received from the destination (since 2.7)

page-size: int

The number of bytes per page for the various page-based statistics (since 2.10)

multifd-bytes: int

The number of bytes sent through multifd (since 3.0)

pages-per-second: int

the number of memory pages transferred per second (Since 4.0)

precopy-bytes: int

The number of bytes sent in the pre-copy phase (since 7.0).

downtime-bytes: int

The number of bytes sent while the guest is paused (since 7.0).

postcopy-bytes: int

The number of bytes sent during the post-copy phase (since 7.0).

dirty-sync-missed-zero-copy: int

Number of times dirty RAM synchronization could not avoid copying dirty pages. This is between 0 and dirty-sync-count * multifd-channels. (since 7.1)

Since

0.14

XBZRLECacheStats (Object)

Detailed XBZRLE migration cache statistics

Members

cache-size: int

XBZRLE cache size

bytes: int

amount of bytes already transferred to the target VM

pages: int

amount of pages transferred to the target VM

cache-miss: int

number of cache miss

cache-miss-rate: number

rate of cache miss (since 2.1)

encoding-rate: number

rate of encoded bytes (since 5.1)

overflow: int

number of overflows

Since

1.2

CompressionStats (Object)

Detailed migration compression statistics

Members

pages: int

amount of pages compressed and transferred to the target VM

busy: int

count of times that no free thread was available to compress data

busy-rate: number

rate of thread busy

compressed-size: int

amount of bytes after compression

compression-rate: number

rate of compressed size

Since

3.1

MigrationStatus (Enum)

An enumeration of migration status.

Values

none

no migration has ever happened.

setup

migration process has been initiated.

cancelling

in the process of cancelling migration.

cancelled

cancelling migration is finished.

active

in the process of doing migration.

postcopy-active

like active, but now in postcopy mode. (since 2.5)

postcopy-paused

during postcopy but paused. (since 3.0)

postcopy-recover-setup

setup phase for a postcopy recovery process, preparing for a recovery phase to start. (since 9.1)

postcopy-recover

trying to recover from a paused postcopy. (since 3.0)

completed

migration is finished.

failed

some error occurred during migration process.

colo

VM is in the process of fault tolerance, VM can not get into this state unless colo capability is enabled for migration. (since 2.8)

pre-switchover

Paused before device serialisation. (since 2.11)

device

During device serialisation when pause-before-switchover is enabled (since 2.11)

wait-unplug

wait for device unplug request by guest OS to be completed. (since 4.2)

Since

2.3

VfioStats (Object)

Detailed VFIO devices migration statistics

Members

transferred: int

amount of bytes transferred to the target VM by VFIO devices

Since

5.2

MigrationInfo (Object)

Information about current migration process.

Members

status: MigrationStatus (optional)

MigrationStatus describing the current migration status. If this field is not returned, no migration process has been initiated

ram: MigrationStats (optional)

MigrationStats containing detailed migration status, only returned if status is ‘active’ or ‘completed’(since 1.2)

xbzrle-cache: XBZRLECacheStats (optional)

XBZRLECacheStats containing detailed XBZRLE migration statistics, only returned if XBZRLE feature is on and status is ‘active’ or ‘completed’ (since 1.2)

total-time: int (optional)

total amount of milliseconds since migration started. If migration has ended, it returns the total migration time. (since 1.2)

downtime: int (optional)

only present when migration finishes correctly total downtime in milliseconds for the guest. (since 1.3)

expected-downtime: int (optional)

only present while migration is active expected downtime in milliseconds for the guest in last walk of the dirty bitmap. (since 1.3)

setup-time: int (optional)

amount of setup time in milliseconds before the iterations begin but after the QMP command is issued. This is designed to provide an accounting of any activities (such as RDMA pinning) which may be expensive, but do not actually occur during the iterative migration rounds themselves. (since 1.6)

cpu-throttle-percentage: int (optional)

percentage of time guest cpus are being throttled during auto-converge. This is only present when auto-converge has started throttling guest cpus. (Since 2.7)

error-desc: string (optional)

the human readable error description string. Clients should not attempt to parse the error strings. (Since 2.7)

postcopy-blocktime: int (optional)

total time when all vCPU were blocked during postcopy live migration. This is only present when the postcopy-blocktime migration capability is enabled. (Since 3.0)

postcopy-vcpu-blocktime: array of int (optional)

list of the postcopy blocktime per vCPU. This is only present when the postcopy-blocktime migration capability is enabled. (Since 3.0)

socket-address: array of SocketAddress (optional)

Only used for tcp, to know what the real port is (Since 4.0)

vfio: VfioStats (optional)

VfioStats containing detailed VFIO devices migration statistics, only returned if VFIO device is present, migration is supported by all VFIO devices and status is ‘active’ or ‘completed’ (since 5.2)

blocked-reasons: array of string (optional)

A list of reasons an outgoing migration is blocked. Present and non-empty when migration is blocked. (since 6.0)

dirty-limit-throttle-time-per-round: int (optional)

Maximum throttle time (in microseconds) of virtual CPUs each dirty ring full round, which shows how MigrationCapability dirty-limit affects the guest during live migration. (Since 8.1)

dirty-limit-ring-full-time: int (optional)

Estimated average dirty ring full time (in microseconds) for each dirty ring full round. The value equals the dirty ring memory size divided by the average dirty page rate of the virtual CPU, which can be used to observe the average memory load of the virtual CPU indirectly. Note that zero means guest doesn’t dirty memory. (Since 8.1)

Since

0.14

query-migrate (Command)

Returns information about current migration process. If migration is active there will be another json-object with RAM migration status.

Returns

MigrationInfo

Since

0.14

Example: Before the first migration

 -> { "execute": "query-migrate" }
 <- { "return": {} }

Example: Migration is done and has succeeded

 -> { "execute": "query-migrate" }
 <- { "return": {
         "status": "completed",
         "total-time":12345,
         "setup-time":12345,
         "downtime":12345,
         "ram":{
           "transferred":123,
           "remaining":123,
           "total":246,
           "duplicate":123,
           "normal":123,
           "normal-bytes":123456,
           "dirty-sync-count":15
         }
      }
    }

Example: Migration is done and has failed

 -> { "execute": "query-migrate" }
 <- { "return": { "status": "failed" } }

Example: Migration is being performed

 -> { "execute": "query-migrate" }
 <- {
       "return":{
          "status":"active",
          "total-time":12345,
          "setup-time":12345,
          "expected-downtime":12345,
          "ram":{
             "transferred":123,
             "remaining":123,
             "total":246,
             "duplicate":123,
             "normal":123,
             "normal-bytes":123456,
             "dirty-sync-count":15
          }
       }
    }

Example: Migration is being performed and XBZRLE is active

 -> { "execute": "query-migrate" }
 <- {
       "return":{
          "status":"active",
          "total-time":12345,
          "setup-time":12345,
          "expected-downtime":12345,
          "ram":{
             "total":1057024,
             "remaining":1053304,
             "transferred":3720,
             "duplicate":10,
             "normal":3333,
             "normal-bytes":3412992,
             "dirty-sync-count":15
          },
          "xbzrle-cache":{
             "cache-size":67108864,
             "bytes":20971520,
             "pages":2444343,
             "cache-miss":2244,
             "cache-miss-rate":0.123,
             "encoding-rate":80.1,
             "overflow":34434
          }
       }
    }

MigrationCapability (Enum)

Migration capabilities enumeration

Values

xbzrle

Migration supports xbzrle (Xor Based Zero Run Length Encoding). This feature allows us to minimize migration traffic for certain work loads, by sending compressed difference of the pages

rdma-pin-all

Controls whether or not the entire VM memory footprint is mlock()’d on demand or all at once. Refer to docs/rdma.txt for usage. Disabled by default. (since 2.0)

zero-blocks

During storage migration encode blocks of zeroes efficiently. This essentially saves 1MB of zeroes per block on the wire. Enabling requires source and target VM to support this feature. To enable it is sufficient to enable the capability on the source VM. The feature is disabled by default. (since 1.6)

events

generate events for each migration state change (since 2.4)

auto-converge

If enabled, QEMU will automatically throttle down the guest to speed up convergence of RAM migration. (since 1.6)

postcopy-ram

Start executing on the migration target before all of RAM has been migrated, pulling the remaining pages along as needed. The capacity must have the same setting on both source and target or migration will not even start. NOTE: If the migration fails during postcopy the VM will fail. (since 2.6)

x-colo

If enabled, migration will never end, and the state of the VM on the primary side will be migrated continuously to the VM on secondary side, this process is called COarse-Grain LOck Stepping (COLO) for Non-stop Service. (since 2.8)

release-ram

if enabled, qemu will free the migrated ram pages on the source during postcopy-ram migration. (since 2.9)

return-path

If enabled, migration will use the return path even for precopy. (since 2.10)

pause-before-switchover

Pause outgoing migration before serialising device state and before disabling block IO (since 2.11)

multifd

Use more than one fd for migration (since 4.0)

dirty-bitmaps

If enabled, QEMU will migrate named dirty bitmaps. (since 2.12)

postcopy-blocktime

Calculate downtime for postcopy live migration (since 3.0)

late-block-activate

If enabled, the destination will not activate block devices (and thus take locks) immediately at the end of migration. (since 3.0)

x-ignore-shared

If enabled, QEMU will not migrate shared memory that is accessible on the destination machine. (since 4.0)

validate-uuid

Send the UUID of the source to allow the destination to ensure it is the same. (since 4.2)

background-snapshot

If enabled, the migration stream will be a snapshot of the VM exactly at the point when the migration procedure starts. The VM RAM is saved with running VM. (since 6.0)

zero-copy-send

Controls behavior on sending memory pages on migration. When true, enables a zero-copy mechanism for sending memory pages, if host supports it. Requires that QEMU be permitted to use locked memory for guest RAM pages. (since 7.1)

postcopy-preempt

If enabled, the migration process will allow postcopy requests to preempt precopy stream, so postcopy requests will be handled faster. This is a performance feature and should not affect the correctness of postcopy migration. (since 7.1)

switchover-ack

If enabled, migration will not stop the source VM and complete the migration until an ACK is received from the destination that it’s OK to do so. Exactly when this ACK is sent depends on the migrated devices that use this feature. For example, a device can use it to make sure some of its data is sent and loaded in the destination before doing switchover. This can reduce downtime if devices that support this capability are present. ‘return-path’ capability must be enabled to use it. (since 8.1)

dirty-limit

If enabled, migration will throttle vCPUs as needed to keep their dirty page rate within vcpu-dirty-limit. This can improve responsiveness of large guests during live migration, and can result in more stable read performance. Requires KVM with accelerator property “dirty-ring-size” set. (Since 8.1)

mapped-ram

Migrate using fixed offsets in the migration file for each RAM page. Requires a migration URI that supports seeking, such as a file. (since 9.0)

Features

unstable

Members x-colo and x-ignore-shared are experimental.

deprecated

Member zero-blocks is deprecated as being part of block migration which was already removed.

Since

1.2

MigrationCapabilityStatus (Object)

Migration capability information

Members

capability: MigrationCapability

capability enum

state: boolean

capability state bool

Since

1.2

migrate-set-capabilities (Command)

Enable/Disable the following migration capabilities (like xbzrle)

Arguments

capabilities: array of MigrationCapabilityStatus

json array of capability modifications to make

Since

1.2

Example:

-> { "execute": "migrate-set-capabilities" , "arguments":
     { "capabilities": [ { "capability": "xbzrle", "state": true } ] } }
<- { "return": {} }

query-migrate-capabilities (Command)

Returns information about the current migration capabilities status

Returns

MigrationCapabilityStatus

Since

1.2

Example:

-> { "execute": "query-migrate-capabilities" }
<- { "return": [
      {"state": false, "capability": "xbzrle"},
      {"state": false, "capability": "rdma-pin-all"},
      {"state": false, "capability": "auto-converge"},
      {"state": false, "capability": "zero-blocks"},
      {"state": true, "capability": "events"},
      {"state": false, "capability": "postcopy-ram"},
      {"state": false, "capability": "x-colo"}
   ]}

MultiFDCompression (Enum)

An enumeration of multifd compression methods.

Values

none

no compression.

zlib

use zlib compression method.

zstd (If: CONFIG_ZSTD)

use zstd compression method.

qatzip (If: CONFIG_QATZIP)

use qatzip compression method. (Since 9.2)

qpl (If: CONFIG_QPL)

use qpl compression method. Query Processing Library(qpl) is based on the deflate compression algorithm and use the Intel In-Memory Analytics Accelerator(IAA) accelerated compression and decompression. (Since 9.1)

uadk (If: CONFIG_UADK)

use UADK library compression method. (Since 9.1)

Since

5.0

MigMode (Enum)

Values

normal

the original form of migration. (since 8.2)

cpr-reboot

The migrate command stops the VM and saves state to the URI. After quitting QEMU, the user resumes by running QEMU -incoming.

This mode allows the user to quit QEMU, optionally update and reboot the OS, and restart QEMU. If the user reboots, the URI must persist across the reboot, such as by using a file.

Unlike normal mode, the use of certain local storage options does not block the migration, but the user must not modify the contents of guest block devices between the quit and restart.

This mode supports VFIO devices provided the user first puts the guest in the suspended runstate, such as by issuing guest-suspend-ram to the QEMU guest agent.

Best performance is achieved when the memory backend is shared and the x-ignore-shared migration capability is set, but this is not required. Further, if the user reboots before restarting such a configuration, the shared memory must persist across the reboot, such as by backing it with a dax device.

cpr-reboot may not be used with postcopy, background-snapshot, or COLO.

(since 8.2)

ZeroPageDetection (Enum)

Values

none

Do not perform zero page checking.

legacy

Perform zero page checking in main migration thread.

multifd

Perform zero page checking in multifd sender thread if multifd migration is enabled, else in the main migration thread as for legacy.

Since

9.0

BitmapMigrationBitmapAliasTransform (Object)

Members

persistent: boolean (optional)

If present, the bitmap will be made persistent or transient depending on this parameter.

Since

6.0

BitmapMigrationBitmapAlias (Object)

Members

name: string

The name of the bitmap.

alias: string

An alias name for migration (for example the bitmap name on the opposite site).

transform: BitmapMigrationBitmapAliasTransform (optional)

Allows the modification of the migrated bitmap. (since 6.0)

Since

5.2

BitmapMigrationNodeAlias (Object)

Maps a block node name and the bitmaps it has to aliases for dirty bitmap migration.

Members

node-name: string

A block node name.

alias: string

An alias block node name for migration (for example the node name on the opposite site).

bitmaps: array of BitmapMigrationBitmapAlias

Mappings for the bitmaps on this node.

Since

5.2

MigrationParameter (Enum)

Migration parameters enumeration

Values

announce-initial

Initial delay (in milliseconds) before sending the first announce (Since 4.0)

announce-max

Maximum delay (in milliseconds) between packets in the announcement (Since 4.0)

announce-rounds

Number of self-announce packets sent after migration (Since 4.0)

announce-step

Increase in delay (in milliseconds) between subsequent packets in the announcement (Since 4.0)

throttle-trigger-threshold

The ratio of bytes_dirty_period and bytes_xfer_period to trigger throttling. It is expressed as percentage. The default value is 50. (Since 5.0)

cpu-throttle-initial

Initial percentage of time guest cpus are throttled when migration auto-converge is activated. The default value is 20. (Since 2.7)

cpu-throttle-increment

throttle percentage increase each time auto-converge detects that migration is not making progress. The default value is 10. (Since 2.7)

cpu-throttle-tailslow

Make CPU throttling slower at tail stage At the tail stage of throttling, the Guest is very sensitive to CPU percentage while the cpu-throttle -increment is excessive usually at tail stage. If this parameter is true, we will compute the ideal CPU percentage used by the Guest, which may exactly make the dirty rate match the dirty rate threshold. Then we will choose a smaller throttle increment between the one specified by cpu-throttle-increment and the one generated by ideal CPU percentage. Therefore, it is compatible to traditional throttling, meanwhile the throttle increment won’t be excessive at tail stage. The default value is false. (Since 5.1)

tls-creds

ID of the ‘tls-creds’ object that provides credentials for establishing a TLS connection over the migration data channel. On the outgoing side of the migration, the credentials must be for a ‘client’ endpoint, while for the incoming side the credentials must be for a ‘server’ endpoint. Setting this to a non-empty string enables TLS for all migrations. An empty string means that QEMU will use plain text mode for migration, rather than TLS. (Since 2.7)

tls-hostname

migration target’s hostname for validating the server’s x509 certificate identity. If empty, QEMU will use the hostname from the migration URI, if any. A non-empty value is required when using x509 based TLS credentials and the migration URI does not include a hostname, such as fd: or exec: based migration. (Since 2.7)

Note: empty value works only since 2.9.

tls-authz

ID of the ‘authz’ object subclass that provides access control checking of the TLS x509 certificate distinguished name. This object is only resolved at time of use, so can be deleted and recreated on the fly while the migration server is active. If missing, it will default to denying access (Since 4.0)

max-bandwidth

maximum speed for migration, in bytes per second. (Since 2.8)

avail-switchover-bandwidth

to set the available bandwidth that migration can use during switchover phase. NOTE! This does not limit the bandwidth during switchover, but only for calculations when making decisions to switchover. By default, this value is zero, which means QEMU will estimate the bandwidth automatically. This can be set when the estimated value is not accurate, while the user is able to guarantee such bandwidth is available when switching over. When specified correctly, this can make the switchover decision much more accurate. (Since 8.2)

downtime-limit

set maximum tolerated downtime for migration. maximum downtime in milliseconds (Since 2.8)

x-checkpoint-delay

The delay time (in ms) between two COLO checkpoints in periodic mode. (Since 2.8)

multifd-channels

Number of channels used to migrate data in parallel. This is the same number that the number of sockets used for migration. The default value is 2 (since 4.0)

xbzrle-cache-size

cache size to be used by XBZRLE migration. It needs to be a multiple of the target page size and a power of 2 (Since 2.11)

max-postcopy-bandwidth

Background transfer bandwidth during postcopy. Defaults to 0 (unlimited). In bytes per second. (Since 3.0)

max-cpu-throttle

maximum cpu throttle percentage. Defaults to 99. (Since 3.1)

multifd-compression

Which compression method to use. Defaults to none. (Since 5.0)

multifd-zlib-level

Set the compression level to be used in live migration, the compression level is an integer between 0 and 9, where 0 means no compression, 1 means the best compression speed, and 9 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)

multifd-qatzip-level

Set the compression level to be used in live migration. The level is an integer between 1 and 9, where 1 means the best compression speed, and 9 means the best compression ratio which will consume more CPU. Defaults to 1. (Since 9.2)

multifd-zstd-level

Set the compression level to be used in live migration, the compression level is an integer between 0 and 20, where 0 means no compression, 1 means the best compression speed, and 20 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)

block-bitmap-mapping

Maps block nodes and bitmaps on them to aliases for the purpose of dirty bitmap migration. Such aliases may for example be the corresponding names on the opposite site. The mapping must be one-to-one, but not necessarily complete: On the source, unmapped bitmaps and all bitmaps on unmapped nodes will be ignored. On the destination, encountering an unmapped alias in the incoming migration stream will result in a report, and all further bitmap migration data will then be discarded. Note that the destination does not know about bitmaps it does not receive, so there is no limitation or requirement regarding the number of bitmaps received, or how they are named, or on which nodes they are placed. By default (when this parameter has never been set), bitmap names are mapped to themselves. Nodes are mapped to their block device name if there is one, and to their node name otherwise. (Since 5.2)

x-vcpu-dirty-limit-period

Periodic time (in milliseconds) of dirty limit during live migration. Should be in the range 1 to 1000ms. Defaults to 1000ms. (Since 8.1)

vcpu-dirty-limit

Dirtyrate limit (MB/s) during live migration. Defaults to 1. (Since 8.1)

mode

Migration mode. See description in MigMode. Default is ‘normal’. (Since 8.2)

zero-page-detection

Whether and how to detect zero pages. See description in ZeroPageDetection. Default is ‘multifd’. (since 9.0)

direct-io

Open migration files with O_DIRECT when possible. This only has effect if the mapped-ram capability is enabled. (Since 9.1)

Features

unstable

Members x-checkpoint-delay and x-vcpu-dirty-limit-period are experimental.

Since

2.4

MigrateSetParameters (Object)

Members

announce-initial: int (optional)

Initial delay (in milliseconds) before sending the first announce (Since 4.0)

announce-max: int (optional)

Maximum delay (in milliseconds) between packets in the announcement (Since 4.0)

announce-rounds: int (optional)

Number of self-announce packets sent after migration (Since 4.0)

announce-step: int (optional)

Increase in delay (in milliseconds) between subsequent packets in the announcement (Since 4.0)

throttle-trigger-threshold: int (optional)

The ratio of bytes_dirty_period and bytes_xfer_period to trigger throttling. It is expressed as percentage. The default value is 50. (Since 5.0)

cpu-throttle-initial: int (optional)

Initial percentage of time guest cpus are throttled when migration auto-converge is activated. The default value is 20. (Since 2.7)

cpu-throttle-increment: int (optional)

throttle percentage increase each time auto-converge detects that migration is not making progress. The default value is 10. (Since 2.7)

cpu-throttle-tailslow: boolean (optional)

Make CPU throttling slower at tail stage At the tail stage of throttling, the Guest is very sensitive to CPU percentage while the cpu-throttle -increment is excessive usually at tail stage. If this parameter is true, we will compute the ideal CPU percentage used by the Guest, which may exactly make the dirty rate match the dirty rate threshold. Then we will choose a smaller throttle increment between the one specified by cpu-throttle-increment and the one generated by ideal CPU percentage. Therefore, it is compatible to traditional throttling, meanwhile the throttle increment won’t be excessive at tail stage. The default value is false. (Since 5.1)

tls-creds: StrOrNull (optional)

ID of the ‘tls-creds’ object that provides credentials for establishing a TLS connection over the migration data channel. On the outgoing side of the migration, the credentials must be for a ‘client’ endpoint, while for the incoming side the credentials must be for a ‘server’ endpoint. Setting this to a non-empty string enables TLS for all migrations. An empty string means that QEMU will use plain text mode for migration, rather than TLS. This is the default. (Since 2.7)

tls-hostname: StrOrNull (optional)

migration target’s hostname for validating the server’s x509 certificate identity. If empty, QEMU will use the hostname from the migration URI, if any. A non-empty value is required when using x509 based TLS credentials and the migration URI does not include a hostname, such as fd: or exec: based migration. (Since 2.7)

Note: empty value works only since 2.9.

tls-authz: StrOrNull (optional)

ID of the ‘authz’ object subclass that provides access control checking of the TLS x509 certificate distinguished name. This object is only resolved at time of use, so can be deleted and recreated on the fly while the migration server is active. If missing, it will default to denying access (Since 4.0)

max-bandwidth: int (optional)

maximum speed for migration, in bytes per second. (Since 2.8)

avail-switchover-bandwidth: int (optional)

to set the available bandwidth that migration can use during switchover phase. NOTE! This does not limit the bandwidth during switchover, but only for calculations when making decisions to switchover. By default, this value is zero, which means QEMU will estimate the bandwidth automatically. This can be set when the estimated value is not accurate, while the user is able to guarantee such bandwidth is available when switching over. When specified correctly, this can make the switchover decision much more accurate. (Since 8.2)

downtime-limit: int (optional)

set maximum tolerated downtime for migration. maximum downtime in milliseconds (Since 2.8)

x-checkpoint-delay: int (optional)

The delay time (in ms) between two COLO checkpoints in periodic mode. (Since 2.8)

multifd-channels: int (optional)

Number of channels used to migrate data in parallel. This is the same number that the number of sockets used for migration. The default value is 2 (since 4.0)

xbzrle-cache-size: int (optional)

cache size to be used by XBZRLE migration. It needs to be a multiple of the target page size and a power of 2 (Since 2.11)

max-postcopy-bandwidth: int (optional)

Background transfer bandwidth during postcopy. Defaults to 0 (unlimited). In bytes per second. (Since 3.0)

max-cpu-throttle: int (optional)

maximum cpu throttle percentage. Defaults to 99. (Since 3.1)

multifd-compression: MultiFDCompression (optional)

Which compression method to use. Defaults to none. (Since 5.0)

multifd-zlib-level: int (optional)

Set the compression level to be used in live migration, the compression level is an integer between 0 and 9, where 0 means no compression, 1 means the best compression speed, and 9 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)

multifd-qatzip-level: int (optional)

Set the compression level to be used in live migration. The level is an integer between 1 and 9, where 1 means the best compression speed, and 9 means the best compression ratio which will consume more CPU. Defaults to 1. (Since 9.2)

multifd-zstd-level: int (optional)

Set the compression level to be used in live migration, the compression level is an integer between 0 and 20, where 0 means no compression, 1 means the best compression speed, and 20 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)

block-bitmap-mapping: array of BitmapMigrationNodeAlias (optional)

Maps block nodes and bitmaps on them to aliases for the purpose of dirty bitmap migration. Such aliases may for example be the corresponding names on the opposite site. The mapping must be one-to-one, but not necessarily complete: On the source, unmapped bitmaps and all bitmaps on unmapped nodes will be ignored. On the destination, encountering an unmapped alias in the incoming migration stream will result in a report, and all further bitmap migration data will then be discarded. Note that the destination does not know about bitmaps it does not receive, so there is no limitation or requirement regarding the number of bitmaps received, or how they are named, or on which nodes they are placed. By default (when this parameter has never been set), bitmap names are mapped to themselves. Nodes are mapped to their block device name if there is one, and to their node name otherwise. (Since 5.2)

x-vcpu-dirty-limit-period: int (optional)

Periodic time (in milliseconds) of dirty limit during live migration. Should be in the range 1 to 1000ms. Defaults to 1000ms. (Since 8.1)

vcpu-dirty-limit: int (optional)

Dirtyrate limit (MB/s) during live migration. Defaults to 1. (Since 8.1)

mode: MigMode (optional)

Migration mode. See description in MigMode. Default is ‘normal’. (Since 8.2)

zero-page-detection: ZeroPageDetection (optional)

Whether and how to detect zero pages. See description in ZeroPageDetection. Default is ‘multifd’. (since 9.0)

direct-io: boolean (optional)

Open migration files with O_DIRECT when possible. This only has effect if the mapped-ram capability is enabled. (Since 9.1)

Features

unstable

Members x-checkpoint-delay and x-vcpu-dirty-limit-period are experimental.

Since

2.4

migrate-set-parameters (Command)

Set various migration parameters.

Arguments

The members of MigrateSetParameters

Since

2.4

Example:

-> { "execute": "migrate-set-parameters" ,
     "arguments": { "multifd-channels": 5 } }
<- { "return": {} }

MigrationParameters (Object)

The optional members aren’t actually optional.

Members

announce-initial: int (optional)

Initial delay (in milliseconds) before sending the first announce (Since 4.0)

announce-max: int (optional)

Maximum delay (in milliseconds) between packets in the announcement (Since 4.0)

announce-rounds: int (optional)

Number of self-announce packets sent after migration (Since 4.0)

announce-step: int (optional)

Increase in delay (in milliseconds) between subsequent packets in the announcement (Since 4.0)

throttle-trigger-threshold: int (optional)

The ratio of bytes_dirty_period and bytes_xfer_period to trigger throttling. It is expressed as percentage. The default value is 50. (Since 5.0)

cpu-throttle-initial: int (optional)

Initial percentage of time guest cpus are throttled when migration auto-converge is activated. (Since 2.7)

cpu-throttle-increment: int (optional)

throttle percentage increase each time auto-converge detects that migration is not making progress. (Since 2.7)

cpu-throttle-tailslow: boolean (optional)

Make CPU throttling slower at tail stage At the tail stage of throttling, the Guest is very sensitive to CPU percentage while the cpu-throttle -increment is excessive usually at tail stage. If this parameter is true, we will compute the ideal CPU percentage used by the Guest, which may exactly make the dirty rate match the dirty rate threshold. Then we will choose a smaller throttle increment between the one specified by cpu-throttle-increment and the one generated by ideal CPU percentage. Therefore, it is compatible to traditional throttling, meanwhile the throttle increment won’t be excessive at tail stage. The default value is false. (Since 5.1)

tls-creds: string (optional)

ID of the ‘tls-creds’ object that provides credentials for establishing a TLS connection over the migration data channel. On the outgoing side of the migration, the credentials must be for a ‘client’ endpoint, while for the incoming side the credentials must be for a ‘server’ endpoint. An empty string means that QEMU will use plain text mode for migration, rather than TLS. (Since 2.7)

Note: 2.8 omits empty tls-creds instead.

tls-hostname: string (optional)

migration target’s hostname for validating the server’s x509 certificate identity. If empty, QEMU will use the hostname from the migration URI, if any. (Since 2.7)

Note: 2.8 omits empty tls-hostname instead.

tls-authz: string (optional)

ID of the ‘authz’ object subclass that provides access control checking of the TLS x509 certificate distinguished name. (Since 4.0)

max-bandwidth: int (optional)

maximum speed for migration, in bytes per second. (Since 2.8)

avail-switchover-bandwidth: int (optional)

to set the available bandwidth that migration can use during switchover phase. NOTE! This does not limit the bandwidth during switchover, but only for calculations when making decisions to switchover. By default, this value is zero, which means QEMU will estimate the bandwidth automatically. This can be set when the estimated value is not accurate, while the user is able to guarantee such bandwidth is available when switching over. When specified correctly, this can make the switchover decision much more accurate. (Since 8.2)

downtime-limit: int (optional)

set maximum tolerated downtime for migration. maximum downtime in milliseconds (Since 2.8)

x-checkpoint-delay: int (optional)

the delay time between two COLO checkpoints. (Since 2.8)

multifd-channels: int (optional)

Number of channels used to migrate data in parallel. This is the same number that the number of sockets used for migration. The default value is 2 (since 4.0)

xbzrle-cache-size: int (optional)

cache size to be used by XBZRLE migration. It needs to be a multiple of the target page size and a power of 2 (Since 2.11)

max-postcopy-bandwidth: int (optional)

Background transfer bandwidth during postcopy. Defaults to 0 (unlimited). In bytes per second. (Since 3.0)

max-cpu-throttle: int (optional)

maximum cpu throttle percentage. Defaults to 99. (Since 3.1)

multifd-compression: MultiFDCompression (optional)

Which compression method to use. Defaults to none. (Since 5.0)

multifd-zlib-level: int (optional)

Set the compression level to be used in live migration, the compression level is an integer between 0 and 9, where 0 means no compression, 1 means the best compression speed, and 9 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)

multifd-qatzip-level: int (optional)

Set the compression level to be used in live migration. The level is an integer between 1 and 9, where 1 means the best compression speed, and 9 means the best compression ratio which will consume more CPU. Defaults to 1. (Since 9.2)

multifd-zstd-level: int (optional)

Set the compression level to be used in live migration, the compression level is an integer between 0 and 20, where 0 means no compression, 1 means the best compression speed, and 20 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)

block-bitmap-mapping: array of BitmapMigrationNodeAlias (optional)

Maps block nodes and bitmaps on them to aliases for the purpose of dirty bitmap migration. Such aliases may for example be the corresponding names on the opposite site. The mapping must be one-to-one, but not necessarily complete: On the source, unmapped bitmaps and all bitmaps on unmapped nodes will be ignored. On the destination, encountering an unmapped alias in the incoming migration stream will result in a report, and all further bitmap migration data will then be discarded. Note that the destination does not know about bitmaps it does not receive, so there is no limitation or requirement regarding the number of bitmaps received, or how they are named, or on which nodes they are placed. By default (when this parameter has never been set), bitmap names are mapped to themselves. Nodes are mapped to their block device name if there is one, and to their node name otherwise. (Since 5.2)

x-vcpu-dirty-limit-period: int (optional)

Periodic time (in milliseconds) of dirty limit during live migration. Should be in the range 1 to 1000ms. Defaults to 1000ms. (Since 8.1)

vcpu-dirty-limit: int (optional)

Dirtyrate limit (MB/s) during live migration. Defaults to 1. (Since 8.1)

mode: MigMode (optional)

Migration mode. See description in MigMode. Default is ‘normal’. (Since 8.2)

zero-page-detection: ZeroPageDetection (optional)

Whether and how to detect zero pages. See description in ZeroPageDetection. Default is ‘multifd’. (since 9.0)

direct-io: boolean (optional)

Open migration files with O_DIRECT when possible. This only has effect if the mapped-ram capability is enabled. (Since 9.1)

Features

unstable

Members x-checkpoint-delay and x-vcpu-dirty-limit-period are experimental.

Since

2.4

query-migrate-parameters (Command)

Returns information about the current migration parameters

Returns

MigrationParameters

Since

2.4

Example:

-> { "execute": "query-migrate-parameters" }
<- { "return": {
         "multifd-channels": 2,
         "cpu-throttle-increment": 10,
         "cpu-throttle-initial": 20,
         "max-bandwidth": 33554432,
         "downtime-limit": 300
      }
   }

migrate-start-postcopy (Command)

Followup to a migration command to switch the migration to postcopy mode. The postcopy-ram capability must be set on both source and destination before the original migration command.

Since

2.5

Example:

-> { "execute": "migrate-start-postcopy" }
<- { "return": {} }

MIGRATION (Event)

Emitted when a migration event happens

Arguments

status: MigrationStatus

MigrationStatus describing the current migration status.

Since

2.4

Example:

<- {"timestamp": {"seconds": 1432121972, "microseconds": 744001},
    "event": "MIGRATION",
    "data": {"status": "completed"} }

MIGRATION_PASS (Event)

Emitted from the source side of a migration at the start of each pass (when it syncs the dirty bitmap)

Arguments

pass: int

An incrementing count (starting at 1 on the first pass)

Since

2.6

Example:

<- { "timestamp": {"seconds": 1449669631, "microseconds": 239225},
      "event": "MIGRATION_PASS", "data": {"pass": 2} }

COLOMessage (Enum)

The message transmission between Primary side and Secondary side.

Values

checkpoint-ready

Secondary VM (SVM) is ready for checkpointing

checkpoint-request

Primary VM (PVM) tells SVM to prepare for checkpointing

checkpoint-reply

SVM gets PVM’s checkpoint request

vmstate-send

VM’s state will be sent by PVM.

vmstate-size

The total size of VMstate.

vmstate-received

VM’s state has been received by SVM.

vmstate-loaded

VM’s state has been loaded by SVM.

Since

2.8

COLOMode (Enum)

The COLO current mode.

Values

none

COLO is disabled.

primary

COLO node in primary side.

secondary

COLO node in slave side.

Since

2.8

FailoverStatus (Enum)

An enumeration of COLO failover status

Values

none

no failover has ever happened

require

got failover requirement but not handled

active

in the process of doing failover

completed

finish the process of failover

relaunch

restart the failover process, from ‘none’ -> ‘completed’ (Since 2.9)

Since

2.8

COLO_EXIT (Event)

Emitted when VM finishes COLO mode due to some errors happening or at the request of users.

Arguments

mode: COLOMode

report COLO mode when COLO exited.

reason: COLOExitReason

describes the reason for the COLO exit.

Since

3.1

Example:

<- { "timestamp": {"seconds": 2032141960, "microseconds": 417172},
     "event": "COLO_EXIT", "data": {"mode": "primary", "reason": "request" } }

COLOExitReason (Enum)

The reason for a COLO exit.

Values

none

failover has never happened. This state does not occur in the COLO_EXIT event, and is only visible in the result of query-colo-status.

request

COLO exit is due to an external request.

error

COLO exit is due to an internal error.

processing

COLO is currently handling a failover (since 4.0).

Since

3.1

x-colo-lost-heartbeat (Command)

Tell qemu that heartbeat is lost, request it to do takeover procedures. If this command is sent to the PVM, the Primary side will exit COLO mode. If sent to the Secondary, the Secondary side will run failover work, then takes over server operation to become the service VM.

Features

unstable

This command is experimental.

Since

2.8

Example:

-> { "execute": "x-colo-lost-heartbeat" }
<- { "return": {} }

If

CONFIG_REPLICATION

migrate_cancel (Command)

Cancel the current executing migration process.

Note

This command succeeds even if there is no migration process running.

Since

0.14

Example:

-> { "execute": "migrate_cancel" }
<- { "return": {} }

migrate-continue (Command)

Continue migration when it’s in a paused state.

Arguments

state: MigrationStatus

The state the migration is currently expected to be in

Since

2.11

Example:

-> { "execute": "migrate-continue" , "arguments":
     { "state": "pre-switchover" } }
<- { "return": {} }

MigrationAddressType (Enum)

The migration stream transport mechanisms.

Values

socket

Migrate via socket.

exec

Direct the migration stream to another process.

rdma

Migrate via RDMA.

file

Direct the migration stream to a file.

Since

8.2

FileMigrationArgs (Object)

Members

filename: string

The file to receive the migration stream

offset: int

The file offset where the migration stream will start

Since

8.2

MigrationExecCommand (Object)

Members

args: array of string

command (list head) and arguments to execute.

Since

8.2

MigrationAddress (Object)

Migration endpoint configuration.

Members

transport: MigrationAddressType

The migration stream transport mechanism

The members of SocketAddress when transport is "socket"

The members of MigrationExecCommand when transport is "exec"

The members of InetSocketAddress when transport is "rdma"

The members of FileMigrationArgs when transport is "file"

Since

8.2

MigrationChannelType (Enum)

The migration channel-type request options.

Values

main

Main outbound migration channel.

Since

8.1

MigrationChannel (Object)

Migration stream channel parameters.

Members

channel-type: MigrationChannelType

Channel type for transferring packet information.

addr: MigrationAddress

Migration endpoint configuration on destination interface.

Since

8.1

migrate (Command)

Migrates the current running guest to another Virtual Machine.

Arguments

uri: string (optional)

the Uniform Resource Identifier of the destination VM

channels: array of MigrationChannel (optional)

list of migration stream channels with each stream in the list connected to a destination interface endpoint.

detach: boolean (optional)

this argument exists only for compatibility reasons and is ignored by QEMU

resume: boolean (optional)

resume one paused migration, default “off”. (since 3.0)

Since

0.14

Notes

1. The ‘query-migrate’ command should be used to check migration’s progress and final result (this information is provided by the ‘status’ member).

2. All boolean arguments default to false.

3. The user Monitor’s “detach” argument is invalid in QMP and should not be used.

4. The uri argument should have the Uniform Resource Identifier of default destination VM. This connection will be bound to default network.

5. For now, number of migration streams is restricted to one, i.e. number of items in ‘channels’ list is just 1.

6. The ‘uri’ and ‘channels’ arguments are mutually exclusive; exactly one of the two should be present.

Example:

-> { "execute": "migrate", "arguments": { "uri": "tcp:0:4446" } }
<- { "return": {} }

-> { "execute": "migrate",
     "arguments": {
         "channels": [ { "channel-type": "main",
                         "addr": { "transport": "socket",
                                   "type": "inet",
                                   "host": "10.12.34.9",
                                   "port": "1050" } } ] } }
<- { "return": {} }

-> { "execute": "migrate",
     "arguments": {
         "channels": [ { "channel-type": "main",
                         "addr": { "transport": "exec",
                                   "args": [ "/bin/nc", "-p", "6000",
                                             "/some/sock" ] } } ] } }
<- { "return": {} }

-> { "execute": "migrate",
     "arguments": {
         "channels": [ { "channel-type": "main",
                         "addr": { "transport": "rdma",
                                   "host": "10.12.34.9",
                                   "port": "1050" } } ] } }
<- { "return": {} }

-> { "execute": "migrate",
     "arguments": {
         "channels": [ { "channel-type": "main",
                         "addr": { "transport": "file",
                                   "filename": "/tmp/migfile",
                                   "offset": "0x1000" } } ] } }
<- { "return": {} }

migrate-incoming (Command)

Start an incoming migration, the qemu must have been started with -incoming defer

Arguments

uri: string (optional)

The Uniform Resource Identifier identifying the source or address to listen on

channels: array of MigrationChannel (optional)

list of migration stream channels with each stream in the list connected to a destination interface endpoint.

exit-on-error: boolean (optional)

Exit on incoming migration failure. Default true. When set to false, the failure triggers a MIGRATION event, and error details could be retrieved with query-migrate. (since 9.1)

Since

2.3

Notes

1. It’s a bad idea to use a string for the uri, but it needs to stay compatible with -incoming and the format of the uri is already exposed above libvirt.

2. QEMU must be started with -incoming defer to allow migrate-incoming to be used.

3. The uri format is the same as for -incoming

4. For now, number of migration streams is restricted to one, i.e. number of items in ‘channels’ list is just 1.

5. The ‘uri’ and ‘channels’ arguments are mutually exclusive; exactly one of the two should be present.

Example:

-> { "execute": "migrate-incoming",
     "arguments": { "uri": "tcp:0:4446" } }
<- { "return": {} }

-> { "execute": "migrate-incoming",
     "arguments": {
         "channels": [ { "channel-type": "main",
                         "addr": { "transport": "socket",
                                   "type": "inet",
                                   "host": "10.12.34.9",
                                   "port": "1050" } } ] } }
<- { "return": {} }

-> { "execute": "migrate-incoming",
     "arguments": {
         "channels": [ { "channel-type": "main",
                         "addr": { "transport": "exec",
                                   "args": [ "/bin/nc", "-p", "6000",
                                             "/some/sock" ] } } ] } }
<- { "return": {} }

-> { "execute": "migrate-incoming",
     "arguments": {
         "channels": [ { "channel-type": "main",
                         "addr": { "transport": "rdma",
                                   "host": "10.12.34.9",
                                   "port": "1050" } } ] } }
<- { "return": {} }

xen-save-devices-state (Command)

Save the state of all devices to file. The RAM and the block devices of the VM are not saved by this command.

Arguments

filename: string

the file to save the state of the devices to as binary data. See xen-save-devices-state.txt for a description of the binary format.

live: boolean (optional)

Optional argument to ask QEMU to treat this command as part of a live migration. Default to true. (since 2.11)

Since

1.1

Example:

-> { "execute": "xen-save-devices-state",
     "arguments": { "filename": "/tmp/save" } }
<- { "return": {} }

xen-set-global-dirty-log (Command)

Enable or disable the global dirty log mode.

Arguments

enable: boolean

true to enable, false to disable.

Since

1.3

Example:

-> { "execute": "xen-set-global-dirty-log",
     "arguments": { "enable": true } }
<- { "return": {} }

xen-load-devices-state (Command)

Load the state of all devices from file. The RAM and the block devices of the VM are not loaded by this command.

Arguments

filename: string

the file to load the state of the devices from as binary data. See xen-save-devices-state.txt for a description of the binary format.

Since

2.7

Example:

-> { "execute": "xen-load-devices-state",
     "arguments": { "filename": "/tmp/resume" } }
<- { "return": {} }

xen-set-replication (Command)

Enable or disable replication.

Arguments

enable: boolean

true to enable, false to disable.

primary: boolean

true for primary or false for secondary.

failover: boolean (optional)

true to do failover, false to stop. Cannot be specified if ‘enable’ is true. Default value is false.

Example:

-> { "execute": "xen-set-replication",
     "arguments": {"enable": true, "primary": false} }
<- { "return": {} }

Since

2.9

If

CONFIG_REPLICATION

ReplicationStatus (Object)

The result format for ‘query-xen-replication-status’.

Members

error: boolean

true if an error happened, false if replication is normal.

desc: string (optional)

the human readable error description string, when error is ‘true’.

Since

2.9

If

CONFIG_REPLICATION

query-xen-replication-status (Command)

Query replication status while the vm is running.

Returns

A ReplicationStatus object showing the status.

Example:

-> { "execute": "query-xen-replication-status" }
<- { "return": { "error": false } }

Since

2.9

If

CONFIG_REPLICATION

xen-colo-do-checkpoint (Command)

Xen uses this command to notify replication to trigger a checkpoint.

Example:

-> { "execute": "xen-colo-do-checkpoint" }
<- { "return": {} }

Since

2.9

If

CONFIG_REPLICATION

COLOStatus (Object)

The result format for ‘query-colo-status’.

Members

mode: COLOMode

COLO running mode. If COLO is running, this field will return ‘primary’ or ‘secondary’.

last-mode: COLOMode

COLO last running mode. If COLO is running, this field will return same like mode field, after failover we can use this field to get last colo mode. (since 4.0)

reason: COLOExitReason

describes the reason for the COLO exit.

Since

3.1

If

CONFIG_REPLICATION

query-colo-status (Command)

Query COLO status while the vm is running.

Returns

A COLOStatus object showing the status.

Example:

-> { "execute": "query-colo-status" }
<- { "return": { "mode": "primary", "last-mode": "none", "reason": "request" } }

Since

3.1

If

CONFIG_REPLICATION

migrate-recover (Command)

Provide a recovery migration stream URI.

Arguments

uri: string

the URI to be used for the recovery of migration stream.

Example:

-> { "execute": "migrate-recover",
     "arguments": { "uri": "tcp:192.168.1.200:12345" } }
<- { "return": {} }

Since

3.0

migrate-pause (Command)

Pause a migration. Currently it only supports postcopy.

Example:

-> { "execute": "migrate-pause" }
<- { "return": {} }

Since

3.0

UNPLUG_PRIMARY (Event)

Emitted from source side of a migration when migration state is WAIT_UNPLUG. Device was unplugged by guest operating system. Device resources in QEMU are kept on standby to be able to re-plug it in case of migration failure.

Arguments

device-id: string

QEMU device id of the unplugged device

Since

4.2

Example:

<- { "event": "UNPLUG_PRIMARY",
     "data": { "device-id": "hostdev0" },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

DirtyRateVcpu (Object)

Dirty rate of vcpu.

Members

id: int

vcpu index.

dirty-rate: int

dirty rate.

Since

6.2

DirtyRateStatus (Enum)

Dirty page rate measurement status.

Values

unstarted

measuring thread has not been started yet

measuring

measuring thread is running

measured

dirty page rate is measured and the results are available

Since

5.2

DirtyRateMeasureMode (Enum)

Method used to measure dirty page rate. Differences between available methods are explained in calc-dirty-rate.

Values

page-sampling

use page sampling

dirty-ring

use dirty ring

dirty-bitmap

use dirty bitmap

Since

6.2

TimeUnit (Enum)

Specifies unit in which time-related value is specified.

Values

second

value is in seconds

millisecond

value is in milliseconds

Since

8.2

DirtyRateInfo (Object)

Information about measured dirty page rate.

Members

dirty-rate: int (optional)

an estimate of the dirty page rate of the VM in units of MiB/s. Value is present only when status is ‘measured’.

status: DirtyRateStatus

current status of dirty page rate measurements

start-time: int

start time in units of second for calculation

calc-time: int

time period for which dirty page rate was measured, expressed and rounded down to calc-time-unit.

calc-time-unit: TimeUnit

time unit of calc-time (Since 8.2)

sample-pages: int

number of sampled pages per GiB of guest memory. Valid only in page-sampling mode (Since 6.1)

mode: DirtyRateMeasureMode

mode that was used to measure dirty page rate (Since 6.2)

vcpu-dirty-rate: array of DirtyRateVcpu (optional)

dirty rate for each vCPU if dirty-ring mode was specified (Since 6.2)

Since

5.2

calc-dirty-rate (Command)

Start measuring dirty page rate of the VM. Results can be retrieved with query-dirty-rate after measurements are completed.

Dirty page rate is the number of pages changed in a given time period expressed in MiB/s. The following methods of calculation are available:

1. In page sampling mode, a random subset of pages are selected and hashed twice: once at the beginning of measurement time period, and once again at the end. If two hashes for some page are different, the page is counted as changed. Since this method relies on sampling and hashing, calculated dirty page rate is only an estimate of its true value. Increasing sample-pages improves estimation quality at the cost of higher computational overhead.

2. Dirty bitmap mode captures writes to memory (for example by temporarily revoking write access to all pages) and counting page faults. Information about modified pages is collected into a bitmap, where each bit corresponds to one guest page. This mode requires that KVM accelerator property “dirty-ring-size” is not set.

3. Dirty ring mode is similar to dirty bitmap mode, but the information about modified pages is collected into ring buffer. This mode tracks page modification per each vCPU separately. It requires that KVM accelerator property “dirty-ring-size” is set.

Arguments

calc-time: int

time period for which dirty page rate is calculated. By default it is specified in seconds, but the unit can be set explicitly with calc-time-unit. Note that larger calc-time values will typically result in smaller dirty page rates because page dirtying is a one-time event. Once some page is counted as dirty during calc-time period, further writes to this page will not increase dirty page rate anymore.

calc-time-unit: TimeUnit (optional)

time unit in which calc-time is specified. By default it is seconds. (Since 8.2)

sample-pages: int (optional)

number of sampled pages per each GiB of guest memory. Default value is 512. For 4KiB guest pages this corresponds to sampling ratio of 0.2%. This argument is used only in page sampling mode. (Since 6.1)

mode: DirtyRateMeasureMode (optional)

mechanism for tracking dirty pages. Default value is ‘page-sampling’. Others are ‘dirty-bitmap’ and ‘dirty-ring’. (Since 6.1)

Since

5.2

Example:

-> {"execute": "calc-dirty-rate", "arguments": {"calc-time": 1,
                                                "sample-pages": 512} }
<- { "return": {} }

Example:

Measure dirty rate using dirty bitmap for 500 milliseconds:

-> {"execute": "calc-dirty-rate", "arguments": {"calc-time": 500,
    "calc-time-unit": "millisecond", "mode": "dirty-bitmap"} }

<- { "return": {} }

query-dirty-rate (Command)

Query results of the most recent invocation of calc-dirty-rate.

Arguments

calc-time-unit: TimeUnit (optional)

time unit in which to report calculation time. By default it is reported in seconds. (Since 8.2)

Since

5.2

Example: Measurement is in progress

 <- {"status": "measuring", "sample-pages": 512,
     "mode": "page-sampling", "start-time": 1693900454, "calc-time": 10,
     "calc-time-unit": "second"}

Example: Measurement has been completed

 <- {"status": "measured", "sample-pages": 512, "dirty-rate": 108,
     "mode": "page-sampling", "start-time": 1693900454, "calc-time": 10,
     "calc-time-unit": "second"}

DirtyLimitInfo (Object)

Dirty page rate limit information of a virtual CPU.

Members

cpu-index: int

index of a virtual CPU.

limit-rate: int

upper limit of dirty page rate (MB/s) for a virtual CPU, 0 means unlimited.

current-rate: int

current dirty page rate (MB/s) for a virtual CPU.

Since

7.1

set-vcpu-dirty-limit (Command)

Set the upper limit of dirty page rate for virtual CPUs.

Requires KVM with accelerator property “dirty-ring-size” set. A virtual CPU’s dirty page rate is a measure of its memory load. To observe dirty page rates, use calc-dirty-rate.

Arguments

cpu-index: int (optional)

index of a virtual CPU, default is all.

dirty-rate: int

upper limit of dirty page rate (MB/s) for virtual CPUs.

Since

7.1

Example:

-> {"execute": "set-vcpu-dirty-limit"}
    "arguments": { "dirty-rate": 200,
                   "cpu-index": 1 } }
<- { "return": {} }

cancel-vcpu-dirty-limit (Command)

Cancel the upper limit of dirty page rate for virtual CPUs.

Cancel the dirty page limit for the vCPU which has been set with set-vcpu-dirty-limit command. Note that this command requires support from dirty ring, same as the “set-vcpu-dirty-limit”.

Arguments

cpu-index: int (optional)

index of a virtual CPU, default is all.

Since

7.1

Example:

-> {"execute": "cancel-vcpu-dirty-limit"},
    "arguments": { "cpu-index": 1 } }
<- { "return": {} }

query-vcpu-dirty-limit (Command)

Returns information about virtual CPU dirty page rate limits, if any.

Since

7.1

Example:

-> {"execute": "query-vcpu-dirty-limit"}
<- {"return": [
       { "limit-rate": 60, "current-rate": 3, "cpu-index": 0},
       { "limit-rate": 60, "current-rate": 3, "cpu-index": 1}]}

MigrationThreadInfo (Object)

Information about migrationthreads

Members

name: string

the name of migration thread

thread-id: int

ID of the underlying host thread

Since

7.2

query-migrationthreads (Command)

Returns information of migration threads

Features

deprecated

This command is deprecated with no replacement yet.

Returns

MigrationThreadInfo

Since

7.2

snapshot-save (Command)

Save a VM snapshot

Arguments

job-id: string

identifier for the newly created job

tag: string

name of the snapshot to create

vmstate: string

block device node name to save vmstate to

devices: array of string

list of block device node names to save a snapshot to

Applications should not assume that the snapshot save is complete when this command returns. The job commands / events must be used to determine completion and to fetch details of any errors that arise.

Note that execution of the guest CPUs may be stopped during the time it takes to save the snapshot. A future version of QEMU may ensure CPUs are executing continuously.

It is strongly recommended that devices contain all writable block device nodes if a consistent snapshot is required.

If tag already exists, an error will be reported

Example:

-> { "execute": "snapshot-save",
     "arguments": {
        "job-id": "snapsave0",
        "tag": "my-snap",
        "vmstate": "disk0",
        "devices": ["disk0", "disk1"]
     }
   }
<- { "return": { } }
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1432121972, "microseconds": 744001},
    "data": {"status": "created", "id": "snapsave0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1432122172, "microseconds": 744001},
    "data": {"status": "running", "id": "snapsave0"}}
<- {"event": "STOP",
    "timestamp": {"seconds": 1432122372, "microseconds": 744001} }
<- {"event": "RESUME",
    "timestamp": {"seconds": 1432122572, "microseconds": 744001} }
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1432122772, "microseconds": 744001},
    "data": {"status": "waiting", "id": "snapsave0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1432122972, "microseconds": 744001},
    "data": {"status": "pending", "id": "snapsave0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1432123172, "microseconds": 744001},
    "data": {"status": "concluded", "id": "snapsave0"}}
-> {"execute": "query-jobs"}
<- {"return": [{"current-progress": 1,
                "status": "concluded",
                "total-progress": 1,
                "type": "snapshot-save",
                "id": "snapsave0"}]}

Since

6.0

snapshot-load (Command)

Load a VM snapshot

Arguments

job-id: string

identifier for the newly created job

tag: string

name of the snapshot to load.

vmstate: string

block device node name to load vmstate from

devices: array of string

list of block device node names to load a snapshot from

Applications should not assume that the snapshot load is complete when this command returns. The job commands / events must be used to determine completion and to fetch details of any errors that arise.

Note that execution of the guest CPUs will be stopped during the time it takes to load the snapshot.

It is strongly recommended that devices contain all writable block device nodes that can have changed since the original snapshot-save command execution.

Example:

-> { "execute": "snapshot-load",
     "arguments": {
        "job-id": "snapload0",
        "tag": "my-snap",
        "vmstate": "disk0",
        "devices": ["disk0", "disk1"]
     }
   }
<- { "return": { } }
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1472124172, "microseconds": 744001},
    "data": {"status": "created", "id": "snapload0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1472125172, "microseconds": 744001},
    "data": {"status": "running", "id": "snapload0"}}
<- {"event": "STOP",
    "timestamp": {"seconds": 1472125472, "microseconds": 744001} }
<- {"event": "RESUME",
    "timestamp": {"seconds": 1472125872, "microseconds": 744001} }
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1472126172, "microseconds": 744001},
    "data": {"status": "waiting", "id": "snapload0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1472127172, "microseconds": 744001},
    "data": {"status": "pending", "id": "snapload0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1472128172, "microseconds": 744001},
    "data": {"status": "concluded", "id": "snapload0"}}
-> {"execute": "query-jobs"}
<- {"return": [{"current-progress": 1,
                "status": "concluded",
                "total-progress": 1,
                "type": "snapshot-load",
                "id": "snapload0"}]}

Since

6.0

snapshot-delete (Command)

Delete a VM snapshot

Arguments

job-id: string

identifier for the newly created job

tag: string

name of the snapshot to delete.

devices: array of string

list of block device node names to delete a snapshot from

Applications should not assume that the snapshot delete is complete when this command returns. The job commands / events must be used to determine completion and to fetch details of any errors that arise.

Example:

-> { "execute": "snapshot-delete",
     "arguments": {
        "job-id": "snapdelete0",
        "tag": "my-snap",
        "devices": ["disk0", "disk1"]
     }
   }
<- { "return": { } }
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1442124172, "microseconds": 744001},
    "data": {"status": "created", "id": "snapdelete0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1442125172, "microseconds": 744001},
    "data": {"status": "running", "id": "snapdelete0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1442126172, "microseconds": 744001},
    "data": {"status": "waiting", "id": "snapdelete0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1442127172, "microseconds": 744001},
    "data": {"status": "pending", "id": "snapdelete0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "timestamp": {"seconds": 1442128172, "microseconds": 744001},
    "data": {"status": "concluded", "id": "snapdelete0"}}
-> {"execute": "query-jobs"}
<- {"return": [{"current-progress": 1,
                "status": "concluded",
                "total-progress": 1,
                "type": "snapshot-delete",
                "id": "snapdelete0"}]}

Since

6.0

Transactions

Abort (Object)

This action can be used to test transaction failure.

Since

1.6

ActionCompletionMode (Enum)

An enumeration of Transactional completion modes.

Values

individual

Do not attempt to cancel any other Actions if any Actions fail after the Transaction request succeeds. All Actions that can complete successfully will do so without waiting on others. This is the default.

grouped

If any Action fails after the Transaction succeeds, cancel all Actions. Actions do not complete until all Actions are ready to complete. May be rejected by Actions that do not support this completion mode.

Since

2.5

TransactionActionKind (Enum)

Values

abort

Since 1.6

block-dirty-bitmap-add

Since 2.5

block-dirty-bitmap-remove

Since 4.2

block-dirty-bitmap-clear

Since 2.5

block-dirty-bitmap-enable

Since 4.0

block-dirty-bitmap-disable

Since 4.0

block-dirty-bitmap-merge

Since 4.0

blockdev-backup

Since 2.3

blockdev-snapshot

Since 2.5

blockdev-snapshot-internal-sync

Since 1.7

blockdev-snapshot-sync

since 1.1

drive-backup

Since 1.6

Features

deprecated

Member drive-backup is deprecated. Use member blockdev-backup instead.

Since

1.1

AbortWrapper (Object)

Members

data: Abort

Not documented

Since

1.6

BlockDirtyBitmapAddWrapper (Object)

Members

data: BlockDirtyBitmapAdd

Not documented

Since

2.5

BlockDirtyBitmapWrapper (Object)

Members

data: BlockDirtyBitmap

Not documented

Since

2.5

BlockDirtyBitmapMergeWrapper (Object)

Members

data: BlockDirtyBitmapMerge

Not documented

Since

4.0

BlockdevBackupWrapper (Object)

Members

data: BlockdevBackup

Not documented

Since

2.3

BlockdevSnapshotWrapper (Object)

Members

data: BlockdevSnapshot

Not documented

Since

2.5

BlockdevSnapshotInternalWrapper (Object)

Members

data: BlockdevSnapshotInternal

Not documented

Since

1.7

BlockdevSnapshotSyncWrapper (Object)

Members

data: BlockdevSnapshotSync

Not documented

Since

1.1

DriveBackupWrapper (Object)

Members

data: DriveBackup

Not documented

Since

1.6

TransactionAction (Object)

A discriminated record of operations that can be performed with transaction.

Members

type: TransactionActionKind

the operation to be performed

The members of AbortWrapper when type is "abort"

The members of BlockDirtyBitmapAddWrapper when type is "block-dirty-bitmap-add"

The members of BlockDirtyBitmapWrapper when type is "block-dirty-bitmap-remove"

The members of BlockDirtyBitmapWrapper when type is "block-dirty-bitmap-clear"

The members of BlockDirtyBitmapWrapper when type is "block-dirty-bitmap-enable"

The members of BlockDirtyBitmapWrapper when type is "block-dirty-bitmap-disable"

The members of BlockDirtyBitmapMergeWrapper when type is "block-dirty-bitmap-merge"

The members of BlockdevBackupWrapper when type is "blockdev-backup"

The members of BlockdevSnapshotWrapper when type is "blockdev-snapshot"

The members of BlockdevSnapshotInternalWrapper when type is "blockdev-snapshot-internal-sync"

The members of BlockdevSnapshotSyncWrapper when type is "blockdev-snapshot-sync"

The members of DriveBackupWrapper when type is "drive-backup"

Since

1.1

TransactionProperties (Object)

Optional arguments to modify the behavior of a Transaction.

Members

completion-mode: ActionCompletionMode (optional)

Controls how jobs launched asynchronously by Actions will complete or fail as a group. See ActionCompletionMode for details.

Since

2.5

transaction (Command)

Executes a number of transactionable QMP commands atomically. If any operation fails, then the entire set of actions will be abandoned and the appropriate error returned.

For external snapshots, the dictionary contains the device, the file to use for the new snapshot, and the format. The default format, if not specified, is qcow2.

Each new snapshot defaults to being created by QEMU (wiping any contents if the file already exists), but it is also possible to reuse an externally-created file. In the latter case, you should ensure that the new image file has the same contents as the current one; QEMU cannot perform any meaningful check. Typically this is achieved by using the current image file as the backing file for the new image.

On failure, the original disks pre-snapshot attempt will be used.

For internal snapshots, the dictionary contains the device and the snapshot’s name. If an internal snapshot matching name already exists, the request will be rejected. Only some image formats support it, for example, qcow2, and rbd,

On failure, qemu will try delete the newly created internal snapshot in the transaction. When an I/O error occurs during deletion, the user needs to fix it later with qemu-img or other command.

Arguments

actions: array of TransactionAction

List of TransactionAction; information needed for the respective operations.

properties: TransactionProperties (optional)

structure of additional options to control the execution of the transaction. See TransactionProperties for additional detail.

Errors

• Any errors from commands in the transaction

Note

The transaction aborts on the first failure. Therefore, there will be information on only one failed operation returned in an error condition, and subsequent actions will not have been attempted.

Since

1.1

Example:

-> { "execute": "transaction",
     "arguments": { "actions": [
         { "type": "blockdev-snapshot-sync", "data" : { "device": "ide-hd0",
                                     "snapshot-file": "/some/place/my-image",
                                     "format": "qcow2" } },
         { "type": "blockdev-snapshot-sync", "data" : { "node-name": "myfile",
                                     "snapshot-file": "/some/place/my-image2",
                                     "snapshot-node-name": "node3432",
                                     "mode": "existing",
                                     "format": "qcow2" } },
         { "type": "blockdev-snapshot-sync", "data" : { "device": "ide-hd1",
                                     "snapshot-file": "/some/place/my-image2",
                                     "mode": "existing",
                                     "format": "qcow2" } },
         { "type": "blockdev-snapshot-internal-sync", "data" : {
                                     "device": "ide-hd2",
                                     "name": "snapshot0" } } ] } }
<- { "return": {} }

Tracing

TraceEventState (Enum)

State of a tracing event.

Values

unavailable

The event is statically disabled.

disabled

The event is dynamically disabled.

enabled

The event is dynamically enabled.

Since

2.2

TraceEventInfo (Object)

Information of a tracing event.

Members

name: string

Event name.

state: TraceEventState

Tracing state.

Since

2.2

trace-event-get-state (Command)

Query the state of events.

Arguments

name: string

Event name pattern (case-sensitive glob).

Returns

a list of TraceEventInfo for the matching events

Since

2.2

Example:

-> { "execute": "trace-event-get-state",
     "arguments": { "name": "qemu_memalign" } }
<- { "return": [ { "name": "qemu_memalign", "state": "disabled", "vcpu": false } ] }

trace-event-set-state (Command)

Set the dynamic tracing state of events.

Arguments

name: string

Event name pattern (case-sensitive glob).

enable: boolean

Whether to enable tracing.

ignore-unavailable: boolean (optional)

Do not match unavailable events with name.

Since

2.2

Example:

-> { "execute": "trace-event-set-state",
     "arguments": { "name": "qemu_memalign", "enable": true } }
<- { "return": {} }

Compatibility policy

CompatPolicyInput (Enum)

Policy for handling “funny” input.

Values

accept

Accept silently

reject

Reject with an error

crash

abort() the process

Since

6.0

CompatPolicyOutput (Enum)

Policy for handling “funny” output.

Values

accept

Pass on unchanged

hide

Filter out

Since

6.0

CompatPolicy (Object)

Policy for handling deprecated management interfaces.

This is intended for testing users of the management interfaces.

Limitation: covers only syntactic aspects of QMP, i.e. stuff tagged with feature ‘deprecated’ or ‘unstable’. We may want to extend it to cover semantic aspects and CLI.

Limitation: deprecated-output policy hide is not implemented for enumeration values. They behave the same as with policy accept.

Members

deprecated-input: CompatPolicyInput (optional)

how to handle deprecated input (default ‘accept’)

deprecated-output: CompatPolicyOutput (optional)

how to handle deprecated output (default ‘accept’)

unstable-input: CompatPolicyInput (optional)

how to handle unstable input (default ‘accept’) (since 6.2)

unstable-output: CompatPolicyOutput (optional)

how to handle unstable output (default ‘accept’) (since 6.2)

Since

6.0

QMP monitor control

qmp_capabilities (Command)

Enable QMP capabilities.

Arguments

enable: array of QMPCapability (optional)

An optional list of QMPCapability values to enable. The client must not enable any capability that is not mentioned in the QMP greeting message. If the field is not provided, it means no QMP capabilities will be enabled. (since 2.12)

Example:

-> { "execute": "qmp_capabilities",
     "arguments": { "enable": [ "oob" ] } }
<- { "return": {} }

Note

This command is valid exactly when first connecting: it must be issued before any other command will be accepted, and will fail once the monitor is accepting other commands. (see QEMU Machine Protocol Specification)

Note

The QMP client needs to explicitly enable QMP capabilities, otherwise all the QMP capabilities will be turned off by default.

Since

0.13

QMPCapability (Enum)

Enumeration of capabilities to be advertised during initial client connection, used for agreeing on particular QMP extension behaviors.

Values

oob

QMP ability to support out-of-band requests. (Please refer to qmp-spec.rst for more information on OOB)

Since

2.12

VersionTriple (Object)

A three-part version number.

Members

major: int

The major version number.

minor: int

The minor version number.

micro: int

The micro version number.

Since

2.4

VersionInfo (Object)

A description of QEMU’s version.

Members

qemu: VersionTriple

The version of QEMU. By current convention, a micro version of 50 signifies a development branch. A micro version greater than or equal to 90 signifies a release candidate for the next minor version. A micro version of less than 50 signifies a stable release.

package: string

QEMU will always set this field to an empty string. Downstream versions of QEMU should set this to a non-empty string. The exact format depends on the downstream however it highly recommended that a unique name is used.

Since

0.14

query-version (Command)

Returns the current version of QEMU.

Returns

A VersionInfo object describing the current version of QEMU.

Since

0.14

Example:

-> { "execute": "query-version" }
<- {
      "return":{
         "qemu":{
            "major":0,
            "minor":11,
            "micro":5
         },
         "package":""
      }
   }

CommandInfo (Object)

Information about a QMP command

Members

name: string

The command name

Since

0.14

query-commands (Command)

Return a list of supported QMP commands by this server

Returns

A list of CommandInfo for all supported commands

Since

0.14

Example:

-> { "execute": "query-commands" }
<- {
     "return":[
        {
           "name":"query-balloon"
        },
        {
           "name":"system_powerdown"
        },
        ...
     ]
   }

This example has been shortened as the real response is too long.

quit (Command)

This command will cause the QEMU process to exit gracefully. While every attempt is made to send the QMP response before terminating, this is not guaranteed. When using this interface, a premature EOF would not be unexpected.

Since

0.14

Example:

-> { "execute": "quit" }
<- { "return": {} }

MonitorMode (Enum)

An enumeration of monitor modes.

Values

readline

HMP monitor (human-oriented command line interface)

control

QMP monitor (JSON-based machine interface)

Since

5.0

MonitorOptions (Object)

Options to be used for adding a new monitor.

Members

id: string (optional)

Name of the monitor

mode: MonitorMode (optional)

Selects the monitor mode (default: readline in the system emulator, control in qemu-storage-daemon)

pretty: boolean (optional)

Enables pretty printing (QMP only)

chardev: string

Name of a character device to expose the monitor on

Since

5.0

QMP introspection

query-qmp-schema (Command)

Command query-qmp-schema exposes the QMP wire ABI as an array of SchemaInfo. This lets QMP clients figure out what commands and events are available in this QEMU, and their parameters and results.

However, the SchemaInfo can’t reflect all the rules and restrictions that apply to QMP. It’s interface introspection (figuring out what’s there), not interface specification. The specification is in the QAPI schema.

Furthermore, while we strive to keep the QMP wire format backwards-compatible across qemu versions, the introspection output is not guaranteed to have the same stability. For example, one version of qemu may list an object member as an optional non-variant, while another lists the same member only through the object’s variants; or the type of a member may change from a generic string into a specific enum or from one specific type into an alternate that includes the original type alongside something else.

Returns

array of SchemaInfo, where each element describes an entity in the ABI: command, event, type, …

The order of the various SchemaInfo is unspecified; however, all names are guaranteed to be unique (no name will be duplicated with different meta-types).

Note

The QAPI schema is also used to help define internal interfaces, by defining QAPI types. These are not part of the QMP wire ABI, and therefore not returned by this command.

Since

2.5

SchemaMetaType (Enum)

This is a SchemaInfo’s meta type, i.e. the kind of entity it describes.

Values

builtin

a predefined type such as ‘int’ or ‘bool’.

enum

an enumeration type

array

an array type

object

an object type (struct or union)

alternate

an alternate type

command

a QMP command

event

a QMP event

Since

2.5

SchemaInfo (Object)

Members

name: string

the entity’s name, inherited from base. The SchemaInfo is always referenced by this name. Commands and events have the name defined in the QAPI schema. Unlike command and event names, type names are not part of the wire ABI. Consequently, type names are meaningless strings here, although they are still guaranteed unique regardless of meta-type.

meta-type: SchemaMetaType

the entity’s meta type, inherited from base.

features: array of string (optional)

names of features associated with the entity, in no particular order. (since 4.1 for object types, 4.2 for commands, 5.0 for the rest)

The members of SchemaInfoBuiltin when meta-type is "builtin"

The members of SchemaInfoEnum when meta-type is "enum"

The members of SchemaInfoArray when meta-type is "array"

The members of SchemaInfoObject when meta-type is "object"

The members of SchemaInfoAlternate when meta-type is "alternate"

The members of SchemaInfoCommand when meta-type is "command"

The members of SchemaInfoEvent when meta-type is "event"

Since

2.5

SchemaInfoBuiltin (Object)

Additional SchemaInfo members for meta-type ‘builtin’.

Members

json-type: JSONType

the JSON type used for this type on the wire.

Since

2.5

JSONType (Enum)

The four primitive and two structured types according to RFC 8259 section 1, plus ‘int’ (split off ‘number’), plus the obvious top type ‘value’.

Values

string

JSON string

number

JSON number

int

JSON number that is an integer

boolean

literal false or true

null

literal null

object

JSON object

array

JSON array

value

any JSON value

Since

2.5

SchemaInfoEnum (Object)

Additional SchemaInfo members for meta-type ‘enum’.

Members

members: array of SchemaInfoEnumMember

the enum type’s members, in no particular order (since 6.2).

values: array of string

the enumeration type’s member names, in no particular order. Redundant with members. Just for backward compatibility.

Features

deprecated

Member values is deprecated. Use members instead.

Values of this type are JSON string on the wire.

Since

2.5

SchemaInfoEnumMember (Object)

An object member.

Members

name: string

the member’s name, as defined in the QAPI schema.

features: array of string (optional)

names of features associated with the member, in no particular order.

Since

6.2

SchemaInfoArray (Object)

Additional SchemaInfo members for meta-type ‘array’.

Members

element-type: string

the array type’s element type.

Values of this type are JSON array on the wire.

Since

2.5

SchemaInfoObject (Object)

Additional SchemaInfo members for meta-type ‘object’.

Members

members: array of SchemaInfoObjectMember

the object type’s (non-variant) members, in no particular order.

tag: string (optional)

the name of the member serving as type tag. An element of members with this name must exist.

variants: array of SchemaInfoObjectVariant (optional)

variant members, i.e. additional members that depend on the type tag’s value. Present exactly when tag is present. The variants are in no particular order, and may even differ from the order of the values of the enum type of the tag.

Values of this type are JSON object on the wire.

Since

2.5

SchemaInfoObjectMember (Object)

An object member.

Members

name: string

the member’s name, as defined in the QAPI schema.

type: string

the name of the member’s type.

default: value (optional)

default when used as command parameter. If absent, the parameter is mandatory. If present, the value must be null. The parameter is optional, and behavior when it’s missing is not specified here. Future extension: if present and non-null, the parameter is optional, and defaults to this value.

features: array of string (optional)

names of features associated with the member, in no particular order. (since 5.0)

Since

2.5

SchemaInfoObjectVariant (Object)

The variant members for a value of the type tag.

Members

case: string

a value of the type tag.

type: string

the name of the object type that provides the variant members when the type tag has value case.

Since

2.5

SchemaInfoAlternate (Object)

Additional SchemaInfo members for meta-type ‘alternate’.

Members

members: array of SchemaInfoAlternateMember

the alternate type’s members, in no particular order. The members’ wire encoding is distinct, see How to use the QAPI code generator section Alternate types.

On the wire, this can be any of the members.

Since

2.5

SchemaInfoAlternateMember (Object)

An alternate member.

Members

type: string

the name of the member’s type.

Since

2.5

SchemaInfoCommand (Object)

Additional SchemaInfo members for meta-type ‘command’.

Members

arg-type: string

the name of the object type that provides the command’s parameters.

ret-type: string

the name of the command’s result type.

allow-oob: boolean (optional)

whether the command allows out-of-band execution, defaults to false (Since: 2.12)

Since

2.5

SchemaInfoEvent (Object)

Additional SchemaInfo members for meta-type ‘event’.

Members

arg-type: string

the name of the object type that provides the event’s parameters.

Since

2.5

QEMU Object Model (QOM)

ObjectPropertyInfo (Object)

Members

name: string

the name of the property

type: string

the type of the property. This will typically come in one of four forms:

1. A primitive type such as ‘u8’, ‘u16’, ‘bool’, ‘str’, or ‘double’. These types are mapped to the appropriate JSON type.

2. A child type in the form ‘child<subtype>’ where subtype is a qdev device type name. Child properties create the composition tree.

3. A link type in the form ‘link<subtype>’ where subtype is a qdev device type name. Link properties form the device model graph.

description: string (optional)

if specified, the description of the property.

default-value: value (optional)

the default value, if any (since 5.0)

Since

1.2

qom-list (Command)

This command will list any properties of a object given a path in the object model.

Arguments

path: string

the path within the object model. See qom-get for a description of this parameter.

Returns

a list of ObjectPropertyInfo that describe the properties of the object.

Since

1.2

Example:

-> { "execute": "qom-list",
     "arguments": { "path": "/chardevs" } }
<- { "return": [ { "name": "type", "type": "string" },
                 { "name": "parallel0", "type": "child<chardev-vc>" },
                 { "name": "serial0", "type": "child<chardev-vc>" },
                 { "name": "mon0", "type": "child<chardev-stdio>" } ] }

qom-get (Command)

This command will get a property from a object model path and return the value.

Arguments

path: string

The path within the object model. There are two forms of supported paths–absolute and partial paths.

Absolute paths are derived from the root object and can follow child<> or link<> properties. Since they can follow link<> properties, they can be arbitrarily long. Absolute paths look like absolute filenames and are prefixed with a leading slash.

Partial paths look like relative filenames. They do not begin with a prefix. The matching rules for partial paths are subtle but designed to make specifying objects easy. At each level of the composition tree, the partial path is matched as an absolute path. The first match is not returned. At least two matches are searched for. A successful result is only returned if only one match is found. If more than one match is found, a flag is return to indicate that the match was ambiguous.

property: string

The property name to read

Returns

The property value. The type depends on the property type. child<> and link<> properties are returned as #str pathnames. All integer property types (u8, u16, etc) are returned as #int.

Since

1.2

Example: Use absolute path

 -> { "execute": "qom-get",
      "arguments": { "path": "/machine/unattached/device[0]",
                     "property": "hotplugged" } }
 <- { "return": false }

Example: Use partial path

 -> { "execute": "qom-get",
      "arguments": { "path": "unattached/sysbus",
                     "property": "type" } }
 <- { "return": "System" }

qom-set (Command)

This command will set a property from a object model path.

Arguments

path: string

see qom-get for a description of this parameter

property: string

the property name to set

value: value

a value who’s type is appropriate for the property type. See qom-get for a description of type mapping.

Since

1.2

Example:

-> { "execute": "qom-set",
     "arguments": { "path": "/machine",
                    "property": "graphics",
                    "value": false } }
<- { "return": {} }

ObjectTypeInfo (Object)

This structure describes a search result from qom-list-types

Members

name: string

the type name found in the search

abstract: boolean (optional)

the type is abstract and can’t be directly instantiated. Omitted if false. (since 2.10)

parent: string (optional)

Name of parent type, if any (since 2.10)

Since

1.1

qom-list-types (Command)

This command will return a list of types given search parameters

Arguments

implements: string (optional)

if specified, only return types that implement this type name

abstract: boolean (optional)

if true, include abstract types in the results

Returns

a list of ObjectTypeInfo or an empty list if no results are found

Since

1.1

qom-list-properties (Command)

List properties associated with a QOM object.

Arguments

typename: string

the type name of an object

Note

Objects can create properties at runtime, for example to describe links between different devices and/or objects. These properties are not included in the output of this command.

Returns

a list of ObjectPropertyInfo describing object properties

Since

2.12

CanHostSocketcanProperties (Object)

Properties for can-host-socketcan objects.

Members

if: string

interface name of the host system CAN bus to connect to

canbus: string

object ID of the can-bus object to connect to the host interface

Since

2.12

If

CONFIG_LINUX

ColoCompareProperties (Object)

Properties for colo-compare objects.

Members

primary_in: string

name of the character device backend to use for the primary input (incoming packets are redirected to outdev)

secondary_in: string

name of the character device backend to use for secondary input (incoming packets are only compared to the input on primary_in and then dropped)

outdev: string

name of the character device backend to use for output

iothread: string

name of the iothread to run in

notify_dev: string (optional)

name of the character device backend to be used to communicate with the remote colo-frame (only for Xen COLO)

compare_timeout: int (optional)

the maximum time to hold a packet from primary_in for comparison with an incoming packet on secondary_in in milliseconds (default: 3000)

expired_scan_cycle: int (optional)

the interval at which colo-compare checks whether packets from primary have timed out, in milliseconds (default: 3000)

max_queue_size: int (optional)

the maximum number of packets to keep in the queue for comparing with incoming packets from secondary_in. If the queue is full and additional packets are received, the additional packets are dropped. (default: 1024)

vnet_hdr_support: boolean (optional)

if true, vnet header support is enabled (default: false)

Since

2.8

CryptodevBackendProperties (Object)

Properties for cryptodev-backend and cryptodev-backend-builtin objects.

Members

queues: int (optional)

the number of queues for the cryptodev backend. Ignored for cryptodev-backend and must be 1 for cryptodev-backend-builtin. (default: 1)

throttle-bps: int (optional)

limit total bytes per second (Since 8.0)

throttle-ops: int (optional)

limit total operations per second (Since 8.0)

Since

2.8

CryptodevVhostUserProperties (Object)

Properties for cryptodev-vhost-user objects.

Members

chardev: string

the name of a Unix domain socket character device that connects to the vhost-user server

The members of CryptodevBackendProperties

Since

2.12

If

CONFIG_VHOST_CRYPTO

DBusVMStateProperties (Object)

Properties for dbus-vmstate objects.

Members

addr: string

the name of the DBus bus to connect to

id-list: string (optional)

a comma separated list of DBus IDs of helpers whose data should be included in the VM state on migration

Since

5.0

NetfilterInsert (Enum)

Indicates where to insert a netfilter relative to a given other filter.

Values

before

insert before the specified filter

behind

insert behind the specified filter

Since

5.0

NetfilterProperties (Object)

Properties for objects of classes derived from netfilter.

Members

netdev: string

id of the network device backend to filter

queue: NetFilterDirection (optional)

indicates which queue(s) to filter (default: all)

status: string (optional)

indicates whether the filter is enabled (“on”) or disabled (“off”) (default: “on”)

position: string (optional)

specifies where the filter should be inserted in the filter list. “head” means the filter is inserted at the head of the filter list, before any existing filters. “tail” means the filter is inserted at the tail of the filter list, behind any existing filters (default). “id=<id>” means the filter is inserted before or behind the filter specified by <id>, depending on the insert property. (default: “tail”)

insert: NetfilterInsert (optional)

where to insert the filter relative to the filter given in position. Ignored if position is “head” or “tail”. (default: behind)

Since

2.5

FilterBufferProperties (Object)

Properties for filter-buffer objects.

Members

interval: int

a non-zero interval in microseconds. All packets arriving in the given interval are delayed until the end of the interval.

The members of NetfilterProperties

Since

2.5

FilterDumpProperties (Object)

Properties for filter-dump objects.

Members

file: string

the filename where the dumped packets should be stored

maxlen: int (optional)

maximum number of bytes in a packet that are stored (default: 65536)

The members of NetfilterProperties

Since

2.5

FilterMirrorProperties (Object)

Properties for filter-mirror objects.

Members

outdev: string

the name of a character device backend to which all incoming packets are mirrored

vnet_hdr_support: boolean (optional)

if true, vnet header support is enabled (default: false)

The members of NetfilterProperties

Since

2.6

FilterRedirectorProperties (Object)

Properties for filter-redirector objects.

At least one of indev or outdev must be present. If both are present, they must not refer to the same character device backend.

Members

indev: string (optional)

the name of a character device backend from which packets are received and redirected to the filtered network device

outdev: string (optional)

the name of a character device backend to which all incoming packets are redirected

vnet_hdr_support: boolean (optional)

if true, vnet header support is enabled (default: false)

The members of NetfilterProperties

Since

2.6

FilterRewriterProperties (Object)

Properties for filter-rewriter objects.

Members

vnet_hdr_support: boolean (optional)

if true, vnet header support is enabled (default: false)

The members of NetfilterProperties

Since

2.8

InputBarrierProperties (Object)

Properties for input-barrier objects.

Members

name: string

the screen name as declared in the screens section of barrier.conf

server: string (optional)

hostname of the Barrier server (default: “localhost”)

port: string (optional)

TCP port of the Barrier server (default: “24800”)

x-origin: string (optional)

x coordinate of the leftmost pixel on the guest screen (default: “0”)

y-origin: string (optional)

y coordinate of the topmost pixel on the guest screen (default: “0”)

width: string (optional)

the width of secondary screen in pixels (default: “1920”)

height: string (optional)

the height of secondary screen in pixels (default: “1080”)

Since

4.2

InputLinuxProperties (Object)

Properties for input-linux objects.

Members

evdev: string

the path of the host evdev device to use

grab_all: boolean (optional)

if true, grab is toggled for all devices (e.g. both keyboard and mouse) instead of just one device (default: false)

repeat: boolean (optional)

enables auto-repeat events (default: false)

grab-toggle: GrabToggleKeys (optional)

the key or key combination that toggles device grab (default: ctrl-ctrl)

Since

2.6

If

CONFIG_LINUX

EventLoopBaseProperties (Object)

Common properties for event loops

Members

aio-max-batch: int (optional)

maximum number of requests in a batch for the AIO engine, 0 means that the engine will use its default. (default: 0)

thread-pool-min: int (optional)

minimum number of threads reserved in the thread pool (default:0)

thread-pool-max: int (optional)

maximum number of threads the thread pool can contain (default:64)

Since

7.1

IothreadProperties (Object)

Properties for iothread objects.

Members

poll-max-ns: int (optional)

the maximum number of nanoseconds to busy wait for events. 0 means polling is disabled (default: 32768 on POSIX hosts, 0 otherwise)

poll-grow: int (optional)

the multiplier used to increase the polling time when the algorithm detects it is missing events due to not polling long enough. 0 selects a default behaviour (default: 0)

poll-shrink: int (optional)

the divisor used to decrease the polling time when the algorithm detects it is spending too long polling without encountering events. 0 selects a default behaviour (default: 0)

The members of EventLoopBaseProperties

The aio-max-batch option is available since 6.1.

Since

2.0

MainLoopProperties (Object)

Properties for the main-loop object.

Members

The members of EventLoopBaseProperties

Since

7.1

MemoryBackendProperties (Object)

Properties for objects of classes derived from memory-backend.

Members

merge: boolean (optional)

if true, mark the memory as mergeable (default depends on the machine type)

dump: boolean (optional)

if true, include the memory in core dumps (default depends on the machine type)

host-nodes: array of int (optional)

the list of NUMA host nodes to bind the memory to

policy: HostMemPolicy (optional)

the NUMA policy (default: ‘default’)

prealloc: boolean (optional)

if true, preallocate memory (default: false)

prealloc-threads: int (optional)

number of CPU threads to use for prealloc (default: 1)

prealloc-context: string (optional)

thread context to use for creation of preallocation threads (default: none) (since 7.2)

share: boolean (optional)

if false, the memory is private to QEMU; if true, it is shared (default false for backends memory-backend-file and memory-backend-ram, true for backends memory-backend-epc, memory-backend-memfd, and memory-backend-shm)

reserve: boolean (optional)

if true, reserve swap space (or huge pages) if applicable (default: true) (since 6.1)

size: int

size of the memory region in bytes

x-use-canonical-path-for-ramblock-id: boolean (optional)

if true, the canonical path is used for ramblock-id. Disable this for 4.0 machine types or older to allow migration with newer QEMU versions. (default: false generally, but true for machine types <= 4.0)

Note

prealloc=true and reserve=false cannot be set at the same time. With reserve=true, the behavior depends on the operating system: for example, Linux will not reserve swap space for shared file mappings – “not applicable”. In contrast, reserve=false will bail out if it cannot be configured accordingly.

Since

2.1

MemoryBackendFileProperties (Object)

Properties for memory-backend-file objects.

Members

align: int (optional)

the base address alignment when QEMU mmap(2)s mem-path. Some backend stores specified by mem-path require an alignment different than the default one used by QEMU, e.g. the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In such cases, users can specify the required alignment via this option. 0 selects a default alignment (currently the page size). (default: 0)

offset: int (optional)

the offset into the target file that the region starts at. You can use this option to back multiple regions with a single file. Must be a multiple of the page size. (default: 0) (since 8.1)

discard-data: boolean (optional)

if true, the file contents can be destroyed when QEMU exits, to avoid unnecessarily flushing data to the backing file. Note that discard-data is only an optimization, and QEMU might not discard file contents if it aborts unexpectedly or is terminated using SIGKILL. (default: false)

mem-path: string

the path to either a shared memory or huge page filesystem mount

pmem: boolean (optional) (If: CONFIG_LIBPMEM)

specifies whether the backing file specified by mem-path is in host persistent memory that can be accessed using the SNIA NVM programming model (e.g. Intel NVDIMM).

readonly: boolean (optional)

if true, the backing file is opened read-only; if false, it is opened read-write. (default: false)

rom: OnOffAuto (optional)

whether to create Read Only Memory (ROM) that cannot be modified by the VM. Any write attempts to such ROM will be denied. Most use cases want writable RAM instead of ROM. However, selected use cases, like R/O NVDIMMs, can benefit from ROM. If set to ‘on’, create ROM; if set to ‘off’, create writable RAM; if set to ‘auto’, the value of the readonly property is used. This property is primarily helpful when we want to have proper RAM in configurations that would traditionally create ROM before this property was introduced: VM templating, where we want to open a file readonly (readonly set to true) and mark the memory to be private for QEMU (share set to false). For this use case, we need writable RAM instead of ROM, and want to set this property to ‘off’. (default: auto, since 8.2)

The members of MemoryBackendProperties

Since

2.1

MemoryBackendMemfdProperties (Object)

Properties for memory-backend-memfd objects.

Members

hugetlb: boolean (optional)

if true, the file to be created resides in the hugetlbfs filesystem (default: false)

hugetlbsize: int (optional)

the hugetlb page size on systems that support multiple hugetlb page sizes (it must be a power of 2 value supported by the system). 0 selects a default page size. This option is ignored if hugetlb is false. (default: 0)

seal: boolean (optional)

if true, create a sealed-file, which will block further resizing of the memory (default: true)

The members of MemoryBackendProperties

Since

2.12

If

CONFIG_LINUX

MemoryBackendShmProperties (Object)

Properties for memory-backend-shm objects.

This memory backend supports only shared memory, which is the default.

Members

The members of MemoryBackendProperties

Since

9.1

If

CONFIG_POSIX

MemoryBackendEpcProperties (Object)

Properties for memory-backend-epc objects.

The merge boolean option is false by default with epc

The dump boolean option is false by default with epc

Members

The members of MemoryBackendProperties

Since

6.2

If

CONFIG_LINUX

PrManagerHelperProperties (Object)

Properties for pr-manager-helper objects.

Members

path: string

the path to a Unix domain socket for connecting to the external helper

Since

2.11

If

CONFIG_LINUX

QtestProperties (Object)

Properties for qtest objects.

Members

chardev: string

the chardev to be used to receive qtest commands on.

log: string (optional)

the path to a log file

Since

6.0

RemoteObjectProperties (Object)

Properties for x-remote-object objects.

Members

fd: string

file descriptor name previously passed via ‘getfd’ command

devid: string

the id of the device to be associated with the file descriptor

Since

6.0

VfioUserServerProperties (Object)

Properties for x-vfio-user-server objects.

Members

socket: SocketAddress

socket to be used by the libvfio-user library

device: string

the ID of the device to be emulated at the server

Since

7.1

IOMMUFDProperties (Object)

Properties for iommufd objects.

Members

fd: string (optional)

file descriptor name previously passed via ‘getfd’ command, which represents a pre-opened /dev/iommu. This allows the iommufd object to be shared across several subsystems (VFIO, VDPA, …), and the file descriptor to be shared with other process, e.g. DPDK. (default: QEMU opens /dev/iommu by itself)

Since

9.0

AcpiGenericInitiatorProperties (Object)

Properties for acpi-generic-initiator objects.

Members

pci-dev: string

PCI device ID to be associated with the node

node: int

NUMA node associated with the PCI device

Since

9.0

AcpiGenericPortProperties (Object)

Properties for acpi-generic-port objects.

Members

pci-bus: string

QOM path of the PCI bus of the hostbridge associated with this SRAT Generic Port Affinity Structure. This is the same as the bus parameter for the root ports attached to this host bridge. The resulting SRAT Generic Port Affinity Structure will refer to the ACPI object in DSDT that represents the host bridge (e.g. ACPI0016 for CXL host bridges). See ACPI 6.5 Section 5.2.16.7 for more information.

node: int

Similar to a NUMA node ID, but instead of providing a reference point used for defining NUMA distances and access characteristics to memory or from an initiator (e.g. CPU), this node defines the boundary point between non-discoverable system buses which must be described by firmware, and a discoverable bus. NUMA distances and access characteristics are defined to and from that point. For system software to establish full initiator to target characteristics this information must be combined with information retrieved from the discoverable part of the path. An example would use CDAT (see UEFI.org) information read from devices and switches in conjunction with link characteristics read from PCIe Configuration space. To get the full path latency from CPU to CXL attached DRAM CXL device: Add the latency from CPU to Generic Port (from HMAT indexed via the the node ID in this SRAT structure) to that for CXL bus links, the latency across intermediate switches and from the EP port to the actual memory. Bandwidth is more complex as there may be interleaving across multiple devices and shared links in the path.

Since

9.2

RngProperties (Object)

Properties for objects of classes derived from rng.

Members

opened: boolean (optional)

if true, the device is opened immediately when applying this option and will probably fail when processing the next option. Don’t use; only provided for compatibility. (default: false)

Features

deprecated

Member opened is deprecated. Setting true doesn’t make sense, and false is already the default.

Since

1.3

RngEgdProperties (Object)

Properties for rng-egd objects.

Members

chardev: string

the name of a character device backend that provides the connection to the RNG daemon

The members of RngProperties

Since

1.3

RngRandomProperties (Object)

Properties for rng-random objects.

Members

filename: string (optional)

the filename of the device on the host to obtain entropy from (default: “/dev/urandom”)

The members of RngProperties

Since

1.3

If

CONFIG_POSIX

SevCommonProperties (Object)

Properties common to objects that are derivatives of sev-common.

Members

sev-device: string (optional)

SEV device to use (default: “/dev/sev”)

cbitpos: int (optional)

C-bit location in page table entry (default: 0)

reduced-phys-bits: int

number of bits in physical addresses that become unavailable when SEV is enabled

kernel-hashes: boolean (optional)

if true, add hashes of kernel/initrd/cmdline to a designated guest firmware page for measured boot with -kernel (default: false) (since 6.2)

Since

9.1

SevGuestProperties (Object)

Properties for sev-guest objects.

Members

dh-cert-file: string (optional)

guest owners DH certificate (encoded with base64)

session-file: string (optional)

guest owners session parameters (encoded with base64)

policy: int (optional)

SEV policy value (default: 0x1)

handle: int (optional)

SEV firmware handle (default: 0)

legacy-vm-type: OnOffAuto (optional)

Use legacy KVM_SEV_INIT KVM interface for creating the VM. The newer KVM_SEV_INIT2 interface, from Linux >= 6.10, syncs additional vCPU state when initializing the VMSA structures, which will result in a different guest measurement. Set this to ‘on’ to force compatibility with older QEMU or kernel versions that rely on legacy KVM_SEV_INIT behavior. ‘auto’ will behave identically to ‘on’, but will automatically switch to using KVM_SEV_INIT2 if the user specifies any additional options that require it. If set to ‘off’, QEMU will require KVM_SEV_INIT2 unconditionally. (default: off) (since 9.1)

The members of SevCommonProperties

Since

2.12

SevSnpGuestProperties (Object)

Properties for sev-snp-guest objects. Most of these are direct arguments for the KVM_SNP_* interfaces documented in the Linux kernel source under Documentation/arch/x86/amd-memory-encryption.rst, which are in turn closely coupled with the SNP_INIT/SNP_LAUNCH_* firmware commands documented in the SEV-SNP Firmware ABI Specification (Rev 0.9).

More usage information is also available in the QEMU source tree under docs/amd-memory-encryption.

Members

policy: int (optional)

the ‘POLICY’ parameter to the SNP_LAUNCH_START command, as defined in the SEV-SNP firmware ABI (default: 0x30000)

guest-visible-workarounds: string (optional)

16-byte, base64-encoded blob to report hypervisor-defined workarounds, corresponding to the ‘GOSVW’ parameter of the SNP_LAUNCH_START command defined in the SEV-SNP firmware ABI (default: all-zero)

id-block: string (optional)

96-byte, base64-encoded blob to provide the ‘ID Block’ structure for the SNP_LAUNCH_FINISH command defined in the SEV-SNP firmware ABI (default: all-zero)

id-auth: string (optional)

4096-byte, base64-encoded blob to provide the ‘ID Authentication Information Structure’ for the SNP_LAUNCH_FINISH command defined in the SEV-SNP firmware ABI (default: all-zero)

author-key-enabled: boolean (optional)

true if ‘id-auth’ blob contains the ‘AUTHOR_KEY’ field defined SEV-SNP firmware ABI (default: false)

host-data: string (optional)

32-byte, base64-encoded, user-defined blob to provide to the guest, as documented for the ‘HOST_DATA’ parameter of the SNP_LAUNCH_FINISH command in the SEV-SNP firmware ABI (default: all-zero)

vcek-disabled: boolean (optional)

Guests are by default allowed to choose between VLEK (Versioned Loaded Endorsement Key) or VCEK (Versioned Chip Endorsement Key) when requesting attestation reports from firmware. Set this to true to disable the use of VCEK. (default: false) (since: 9.1)

The members of SevCommonProperties

Since

9.1

ThreadContextProperties (Object)

Properties for thread context objects.

Members

cpu-affinity: array of int (optional)

the list of host CPU numbers used as CPU affinity for all threads created in the thread context (default: QEMU main thread CPU affinity)

node-affinity: array of int (optional)

the list of host node numbers that will be resolved to a list of host CPU numbers used as CPU affinity. This is a shortcut for specifying the list of host CPU numbers belonging to the host nodes manually by setting cpu-affinity. (default: QEMU main thread affinity)

Since

7.2

ObjectType (Enum)

Values

acpi-generic-initiator

Not documented

acpi-generic-port

Not documented

authz-list

Not documented

authz-listfile

Not documented

authz-pam

Not documented

authz-simple

Not documented

can-bus

Not documented

can-host-socketcan (If: CONFIG_LINUX)

Not documented

colo-compare

Not documented

cryptodev-backend

Not documented

cryptodev-backend-builtin

Not documented

cryptodev-backend-lkcf

Not documented

cryptodev-vhost-user (If: CONFIG_VHOST_CRYPTO)

Not documented

dbus-vmstate

Not documented

filter-buffer

Not documented

filter-dump

Not documented

filter-mirror

Not documented

filter-redirector

Not documented

filter-replay

Not documented

filter-rewriter

Not documented

input-barrier

Not documented

input-linux (If: CONFIG_LINUX)

Not documented

iommufd

Not documented

iothread

Not documented

main-loop

Not documented

memory-backend-epc (If: CONFIG_LINUX)

Not documented

memory-backend-file

Not documented

memory-backend-memfd (If: CONFIG_LINUX)

Not documented

memory-backend-ram

Not documented

memory-backend-shm (If: CONFIG_POSIX)

Not documented

pef-guest

Not documented

pr-manager-helper (If: CONFIG_LINUX)

Not documented

qtest

Not documented

rng-builtin

Not documented

rng-egd

Not documented

rng-random (If: CONFIG_POSIX)

Not documented

secret

Not documented

secret_keyring (If: CONFIG_SECRET_KEYRING)

Not documented

sev-guest

Not documented

sev-snp-guest

Not documented

thread-context

Not documented

s390-pv-guest

Not documented

throttle-group

Not documented

tls-creds-anon

Not documented

tls-creds-psk

Not documented

tls-creds-x509

Not documented

tls-cipher-suites

Not documented

x-remote-object

Not documented

x-vfio-user-server

Not documented

Features

unstable

Members x-remote-object and x-vfio-user-server are experimental.

Since

6.0

ObjectOptions (Object)

Describes the options of a user creatable QOM object.

Members

qom-type: ObjectType

the class name for the object to be created

id: string

the name of the new object

The members of AcpiGenericInitiatorProperties when qom-type is "acpi-generic-initiator"

The members of AcpiGenericPortProperties when qom-type is "acpi-generic-port"

The members of AuthZListProperties when qom-type is "authz-list"

The members of AuthZListFileProperties when qom-type is "authz-listfile"

The members of AuthZPAMProperties when qom-type is "authz-pam"

The members of AuthZSimpleProperties when qom-type is "authz-simple"

The members of CanHostSocketcanProperties when qom-type is "can-host-socketcan" (If: CONFIG_LINUX)

The members of ColoCompareProperties when qom-type is "colo-compare"

The members of CryptodevBackendProperties when qom-type is "cryptodev-backend"

The members of CryptodevBackendProperties when qom-type is "cryptodev-backend-builtin"

The members of CryptodevBackendProperties when qom-type is "cryptodev-backend-lkcf"

The members of CryptodevVhostUserProperties when qom-type is "cryptodev-vhost-user" (If: CONFIG_VHOST_CRYPTO)

The members of DBusVMStateProperties when qom-type is "dbus-vmstate"

The members of FilterBufferProperties when qom-type is "filter-buffer"

The members of FilterDumpProperties when qom-type is "filter-dump"

The members of FilterMirrorProperties when qom-type is "filter-mirror"

The members of FilterRedirectorProperties when qom-type is "filter-redirector"

The members of NetfilterProperties when qom-type is "filter-replay"

The members of FilterRewriterProperties when qom-type is "filter-rewriter"

The members of InputBarrierProperties when qom-type is "input-barrier"

The members of InputLinuxProperties when qom-type is "input-linux" (If: CONFIG_LINUX)

The members of IOMMUFDProperties when qom-type is "iommufd"

The members of IothreadProperties when qom-type is "iothread"

The members of MainLoopProperties when qom-type is "main-loop"

The members of MemoryBackendEpcProperties when qom-type is "memory-backend-epc" (If: CONFIG_LINUX)

The members of MemoryBackendFileProperties when qom-type is "memory-backend-file"

The members of MemoryBackendMemfdProperties when qom-type is "memory-backend-memfd" (If: CONFIG_LINUX)

The members of MemoryBackendProperties when qom-type is "memory-backend-ram"

The members of MemoryBackendShmProperties when qom-type is "memory-backend-shm" (If: CONFIG_POSIX)

The members of PrManagerHelperProperties when qom-type is "pr-manager-helper" (If: CONFIG_LINUX)

The members of QtestProperties when qom-type is "qtest"

The members of RngProperties when qom-type is "rng-builtin"

The members of RngEgdProperties when qom-type is "rng-egd"

The members of RngRandomProperties when qom-type is "rng-random" (If: CONFIG_POSIX)

The members of SecretProperties when qom-type is "secret"

The members of SecretKeyringProperties when qom-type is "secret_keyring" (If: CONFIG_SECRET_KEYRING)

The members of SevGuestProperties when qom-type is "sev-guest"

The members of SevSnpGuestProperties when qom-type is "sev-snp-guest"

The members of ThreadContextProperties when qom-type is "thread-context"

The members of ThrottleGroupProperties when qom-type is "throttle-group"

The members of TlsCredsAnonProperties when qom-type is "tls-creds-anon"

The members of TlsCredsPskProperties when qom-type is "tls-creds-psk"

The members of TlsCredsX509Properties when qom-type is "tls-creds-x509"

The members of TlsCredsProperties when qom-type is "tls-cipher-suites"

The members of RemoteObjectProperties when qom-type is "x-remote-object"

The members of VfioUserServerProperties when qom-type is "x-vfio-user-server"

Since

6.0

object-add (Command)

Create a QOM object.

Arguments

The members of ObjectOptions

Errors

• Error if qom-type is not a valid class name

Since

2.0

Example:

-> { "execute": "object-add",
     "arguments": { "qom-type": "rng-random", "id": "rng1",
                    "filename": "/dev/hwrng" } }
<- { "return": {} }

object-del (Command)

Remove a QOM object.

Arguments

id: string

the name of the QOM object to remove

Errors

• Error if id is not a valid id for a QOM object

Since

2.0

Example:

-> { "execute": "object-del", "arguments": { "id": "rng1" } }
<- { "return": {} }

Device infrastructure (qdev)

device-list-properties (Command)

List properties associated with a device.

Arguments

typename: string

the type name of a device

Returns

a list of ObjectPropertyInfo describing a devices properties

Note

Objects can create properties at runtime, for example to describe links between different devices and/or objects. These properties are not included in the output of this command.

Since

1.2

device_add (Command)

Add a device.

Arguments

driver: string

the name of the new device’s driver

bus: string (optional)

the device’s parent bus (device tree path)

id: string (optional)

the device’s ID, must be unique

Features

json-cli

If present, the “-device” command line option supports JSON syntax with a structure identical to the arguments of this command.

json-cli-hotplug

If present, the “-device” command line option supports JSON syntax without the reference counting leak that broke hot-unplug

Notes

1. Additional arguments depend on the type.

2. For detailed information about this command, please refer to the ‘docs/qdev-device-use.txt’ file.

3. It’s possible to list device properties by running QEMU with the -device DEVICE,help command-line argument, where DEVICE is the device’s name.

Example:

-> { "execute": "device_add",
     "arguments": { "driver": "e1000", "id": "net1",
                    "bus": "pci.0",
                    "mac": "52:54:00:12:34:56" } }
<- { "return": {} }

Since

0.13

device_del (Command)

Remove a device from a guest

Arguments

id: string

the device’s ID or QOM path

Errors

• If id is not a valid device, DeviceNotFound

Note

When this command completes, the device may not be removed from the guest. Hot removal is an operation that requires guest cooperation. This command merely requests that the guest begin the hot removal process. Completion of the device removal process is signaled with a DEVICE_DELETED event. Guest reset will automatically complete removal for all devices. If a guest-side error in the hot removal process is detected, the device will not be removed and a DEVICE_UNPLUG_GUEST_ERROR event is sent. Some errors cannot be detected.

Since

0.14

Example:

-> { "execute": "device_del",
     "arguments": { "id": "net1" } }
<- { "return": {} }

Example:

-> { "execute": "device_del",
     "arguments": { "id": "/machine/peripheral-anon/device[0]" } }
<- { "return": {} }

DEVICE_DELETED (Event)

Emitted whenever the device removal completion is acknowledged by the guest. At this point, it’s safe to reuse the specified device ID. Device removal can be initiated by the guest or by HMP/QMP commands.

Arguments

device: string (optional)

the device’s ID if it has one

path: string

the device’s QOM path

Since

1.5

Example:

<- { "event": "DEVICE_DELETED",
     "data": { "device": "virtio-net-pci-0",
               "path": "/machine/peripheral/virtio-net-pci-0" },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

DEVICE_UNPLUG_GUEST_ERROR (Event)

Emitted when a device hot unplug fails due to a guest reported error.

Arguments

device: string (optional)

the device’s ID if it has one

path: string

the device’s QOM path

Since

6.2

Example:

<- { "event": "DEVICE_UNPLUG_GUEST_ERROR",
     "data": { "device": "core1",
               "path": "/machine/peripheral/core1" },
     "timestamp": { "seconds": 1615570772, "microseconds": 202844 } }

device-sync-config (Command)

Synchronize device configuration from host to guest part. First, copy the configuration from the host part (backend) to the guest part (frontend). Then notify guest software that device configuration changed.

The command may be used to notify the guest about block device capcity change. Currently only vhost-user-blk device supports this.

Arguments

id: string

the device’s ID or QOM path

Features

unstable

The command is experimental.

Since

9.2

Common machine types

S390CpuEntitlement (Enum)

An enumeration of CPU entitlements that can be assumed by a virtual S390 CPU

Values

auto

Not documented

low

Not documented

medium

Not documented

high

Not documented

Since

8.2

CpuTopologyLevel (Enum)

An enumeration of CPU topology levels.

Values

thread

thread level, which would also be called SMT level or logical processor level. The threads option in SMPConfiguration is used to configure the topology of this level.

core

core level. The cores option in SMPConfiguration is used to configure the topology of this level.

module

module level. The modules option in SMPConfiguration is used to configure the topology of this level.

cluster

cluster level. The clusters option in SMPConfiguration is used to configure the topology of this level.

die

die level. The dies option in SMPConfiguration is used to configure the topology of this level.

socket

socket level, which would also be called package level. The sockets option in SMPConfiguration is used to configure the topology of this level.

book

book level. The books option in SMPConfiguration is used to configure the topology of this level.

drawer

drawer level. The drawers option in SMPConfiguration is used to configure the topology of this level.

default

default level. Some architectures will have default topology settings (e.g., cache topology), and this special level means following the architecture-specific settings.

Since

9.2

CacheLevelAndType (Enum)

Caches a system may have. The enumeration value here is the combination of cache level and cache type.

Values

l1d

L1 data cache.

l1i

L1 instruction cache.

l2

L2 (unified) cache.

l3

L3 (unified) cache

Since

9.2

SmpCacheProperties (Object)

Cache information for SMP system.

Members

cache: CacheLevelAndType

Cache name, which is the combination of cache level and cache type.

topology: CpuTopologyLevel

Cache topology level. It accepts the CPU topology enumeration as the parameter, i.e., CPUs in the same topology container share the same cache.

Since

9.2

SmpCachePropertiesWrapper (Object)

List wrapper of SmpCacheProperties.

Members

caches: array of SmpCacheProperties

the list of SmpCacheProperties.

Since 9.2

Machines

SysEmuTarget (Enum)

The comprehensive enumeration of QEMU system emulation (“softmmu”) targets. Run “./configure –help” in the project root directory, and look for the *-softmmu targets near the “–target-list” option. The individual target constants are not documented here, for the time being.

Values

rx

since 5.0

avr

since 5.1

loongarch64

since 7.1

aarch64

Not documented

alpha

Not documented

arm

Not documented

hppa

Not documented

i386

Not documented

m68k

Not documented

microblaze

Not documented

microblazeel

Not documented

mips

Not documented

mips64

Not documented

mips64el

Not documented

mipsel

Not documented

or1k

Not documented

ppc

Not documented

ppc64

Not documented

riscv32

Not documented

riscv64

Not documented

s390x

Not documented

sh4

Not documented

sh4eb

Not documented

sparc

Not documented

sparc64

Not documented

tricore

Not documented

x86_64

Not documented

xtensa

Not documented

xtensaeb

Not documented

Note

The resulting QMP strings can be appended to the “qemu-system-” prefix to produce the corresponding QEMU executable name. This is true even for “qemu-system-x86_64”.

Since

3.0

S390CpuState (Enum)

An enumeration of cpu states that can be assumed by a virtual S390 CPU

Values

uninitialized

Not documented

stopped

Not documented

check-stop

Not documented

operating

Not documented

load

Not documented

Since

2.12

CpuInfoS390 (Object)

Additional information about a virtual S390 CPU

Members

cpu-state: S390CpuState

the virtual CPU’s state

dedicated: boolean (optional)

the virtual CPU’s dedication (since 8.2)

entitlement: S390CpuEntitlement (optional)

the virtual CPU’s entitlement (since 8.2)

Since

2.12

CpuInfoFast (Object)

Information about a virtual CPU

Members

cpu-index: int

index of the virtual CPU

qom-path: string

path to the CPU object in the QOM tree

thread-id: int

ID of the underlying host thread

props: CpuInstanceProperties (optional)

properties associated with a virtual CPU, e.g. the socket id

target: SysEmuTarget

the QEMU system emulation target, which determines which additional fields will be listed (since 3.0)

The members of CpuInfoS390 when target is "s390x"

Since

2.12

query-cpus-fast (Command)

Returns information about all virtual CPUs.

Returns

list of CpuInfoFast

Since

2.12

Example:

-> { "execute": "query-cpus-fast" }
<- { "return": [
        {
            "thread-id": 25627,
            "props": {
                "core-id": 0,
                "thread-id": 0,
                "socket-id": 0
            },
            "qom-path": "/machine/unattached/device[0]",
            "target":"x86_64",
            "cpu-index": 0
        },
        {
            "thread-id": 25628,
            "props": {
                "core-id": 0,
                "thread-id": 0,
                "socket-id": 1
            },
            "qom-path": "/machine/unattached/device[2]",
            "target":"x86_64",
            "cpu-index": 1
        }
    ]
}

CompatProperty (Object)

Property default values specific to a machine type, for use by scripts/compare-machine-types.

Members

qom-type: string

name of the QOM type to which the default applies

property: string

name of its property to which the default applies

value: string

the default value (machine-specific default can overwrite the “default” default, to avoid this use -machine none)

Since

9.1

MachineInfo (Object)

Information describing a machine.

Members

name: string

the name of the machine

alias: string (optional)

an alias for the machine name

is-default: boolean (optional)

whether the machine is default

cpu-max: int

maximum number of CPUs supported by the machine type (since 1.5)

hotpluggable-cpus: boolean

cpu hotplug via -device is supported (since 2.7)

numa-mem-supported: boolean

true if ‘-numa node,mem’ option is supported by the machine type and false otherwise (since 4.1)

deprecated: boolean

if true, the machine type is deprecated and may be removed in future versions of QEMU according to the QEMU deprecation policy (since 4.1)

default-cpu-type: string (optional)

default CPU model typename if none is requested via the -cpu argument. (since 4.2)

default-ram-id: string (optional)

the default ID of initial RAM memory backend (since 5.2)

acpi: boolean

machine type supports ACPI (since 8.0)

compat-props: array of CompatProperty (optional)

The machine type’s compatibility properties. Only present when query-machines argument compat-props is true. (since 9.1)

Features

unstable

Member compat-props is experimental.

Since

1.2

query-machines (Command)

Return a list of supported machines

Arguments

compat-props: boolean (optional)

if true, also return compatibility properties. (default: false) (since 9.1)

Features

unstable

Argument compat-props is experimental.

Returns

a list of MachineInfo

Since

1.2

Example:

-> { "execute": "query-machines", "arguments": { "compat-props": true } }
<- { "return": [
          {
             "hotpluggable-cpus": true,
             "name": "pc-q35-6.2",
             "compat-props": [
                  {
                     "qom-type": "virtio-mem",
                     "property": "unplugged-inaccessible",
                     "value": "off"
                  }
              ],
              "numa-mem-supported": false,
              "default-cpu-type": "qemu64-x86_64-cpu",
              "cpu-max": 288,
              "deprecated": false,
              "default-ram-id": "pc.ram"
          },
          ...
   }

CurrentMachineParams (Object)

Information describing the running machine parameters.

Members

wakeup-suspend-support: boolean

true if the machine supports wake up from suspend

Since

4.0

query-current-machine (Command)

Return information on the current virtual machine.

Returns

CurrentMachineParams

Since

4.0

TargetInfo (Object)

Information describing the QEMU target.

Members

arch: SysEmuTarget

the target architecture

Since

1.2

query-target (Command)

Return information about the target for this QEMU

Returns

TargetInfo

Since

1.2

UuidInfo (Object)

Guest UUID information (Universally Unique Identifier).

Members

UUID: string

the UUID of the guest

Since

0.14

Note

If no UUID was specified for the guest, the nil UUID (all zeroes) is returned.

query-uuid (Command)

Query the guest UUID information.

Returns

The UuidInfo for the guest

Since

0.14

Example:

-> { "execute": "query-uuid" }
<- { "return": { "UUID": "550e8400-e29b-41d4-a716-446655440000" } }

GuidInfo (Object)

GUID information.

Members

guid: string

the globally unique identifier

Since

2.9

query-vm-generation-id (Command)

Show Virtual Machine Generation ID

Since

2.9

system_reset (Command)

Performs a hard reset of a guest.

Since

0.14

Example:

-> { "execute": "system_reset" }
<- { "return": {} }

system_powerdown (Command)

Requests that a guest perform a powerdown operation.

Since

0.14

Note

A guest may or may not respond to this command. This command returning does not indicate that a guest has accepted the request or that it has shut down. Many guests will respond to this command by prompting the user in some way.

Example:

-> { "execute": "system_powerdown" }
<- { "return": {} }

system_wakeup (Command)

Wake up guest from suspend. If the guest has wake-up from suspend support enabled (wakeup-suspend-support flag from query-current-machine), wake-up guest from suspend if the guest is in SUSPENDED state. Return an error otherwise.

Since

1.1

Note

Prior to 4.0, this command does nothing in case the guest isn’t suspended.

Example:

-> { "execute": "system_wakeup" }
<- { "return": {} }

LostTickPolicy (Enum)

Policy for handling lost ticks in timer devices. Ticks end up getting lost when, for example, the guest is paused.

Values

discard

throw away the missed ticks and continue with future injection normally. The guest OS will see the timer jump ahead by a potentially quite significant amount all at once, as if the intervening chunk of time had simply not existed; needless to say, such a sudden jump can easily confuse a guest OS which is not specifically prepared to deal with it. Assuming the guest OS can deal correctly with the time jump, the time in the guest and in the host should now match.

delay

continue to deliver ticks at the normal rate. The guest OS will not notice anything is amiss, as from its point of view time will have continued to flow normally. The time in the guest should now be behind the time in the host by exactly the amount of time during which ticks have been missed.

slew

deliver ticks at a higher rate to catch up with the missed ticks. The guest OS will not notice anything is amiss, as from its point of view time will have continued to flow normally. Once the timer has managed to catch up with all the missing ticks, the time in the guest and in the host should match.

Since

2.0

inject-nmi (Command)

Injects a Non-Maskable Interrupt into the default CPU (x86/s390) or all CPUs (ppc64). The command fails when the guest doesn’t support injecting.

Since

0.14

Note

Prior to 2.1, this command was only supported for x86 and s390 VMs.

Example:

-> { "execute": "inject-nmi" }
<- { "return": {} }

KvmInfo (Object)

Information about support for KVM acceleration

Members

enabled: boolean

true if KVM acceleration is active

present: boolean

true if KVM acceleration is built into this executable

Since

0.14

query-kvm (Command)

Returns information about KVM acceleration

Returns

KvmInfo

Since

0.14

Example:

-> { "execute": "query-kvm" }
<- { "return": { "enabled": true, "present": true } }

NumaOptionsType (Enum)

Values

node

NUMA nodes configuration

dist

NUMA distance configuration (since 2.10)

cpu

property based CPU(s) to node mapping (Since: 2.10)

hmat-lb

memory latency and bandwidth information (Since: 5.0)

hmat-cache

memory side cache information (Since: 5.0)

Since

2.1

NumaOptions (Object)

A discriminated record of NUMA options. (for OptsVisitor)

Members

type: NumaOptionsType

NUMA option type

The members of NumaNodeOptions when type is "node"

The members of NumaDistOptions when type is "dist"

The members of NumaCpuOptions when type is "cpu"

The members of NumaHmatLBOptions when type is "hmat-lb"

The members of NumaHmatCacheOptions when type is "hmat-cache"

Since

2.1

NumaNodeOptions (Object)

Create a guest NUMA node. (for OptsVisitor)

Members

nodeid: int (optional)

NUMA node ID (increase by 1 from 0 if omitted)

cpus: array of int (optional)

VCPUs belonging to this node (assign VCPUS round-robin if omitted)

mem: int (optional)

memory size of this node; mutually exclusive with memdev. Equally divide total memory among nodes if both mem and memdev are omitted.

memdev: string (optional)

memory backend object. If specified for one node, it must be specified for all nodes.

initiator: int (optional)

defined in ACPI 6.3 Chapter 5.2.27.3 Table 5-145, points to the nodeid which has the memory controller responsible for this NUMA node. This field provides additional information as to the initiator node that is closest (as in directly attached) to this node, and therefore has the best performance (since 5.0)

Since

2.1

NumaDistOptions (Object)

Set the distance between 2 NUMA nodes.

Members

src: int

source NUMA node.

dst: int

destination NUMA node.

val: int

NUMA distance from source node to destination node. When a node is unreachable from another node, set the distance between them to 255.

Since

2.10

CXLFixedMemoryWindowOptions (Object)

Create a CXL Fixed Memory Window

Members

size: int

Size of the Fixed Memory Window in bytes. Must be a multiple of 256MiB.

interleave-granularity: int (optional)

Number of contiguous bytes for which accesses will go to a given interleave target. Accepted values [256, 512, 1k, 2k, 4k, 8k, 16k]

targets: array of string

Target root bridge IDs from -device …,id=<ID> for each root bridge.

Since

7.1

CXLFMWProperties (Object)

List of CXL Fixed Memory Windows.

Members

cxl-fmw: array of CXLFixedMemoryWindowOptions

List of CXLFixedMemoryWindowOptions

Since

7.1

X86CPURegister32 (Enum)

A X86 32-bit register

Values

EAX

Not documented

EBX

Not documented

ECX

Not documented

EDX

Not documented

ESP

Not documented

EBP

Not documented

ESI

Not documented

EDI

Not documented

Since

1.5

X86CPUFeatureWordInfo (Object)

Information about a X86 CPU feature word

Members

cpuid-input-eax: int

Input EAX value for CPUID instruction for that feature word

cpuid-input-ecx: int (optional)

Input ECX value for CPUID instruction for that feature word

cpuid-register: X86CPURegister32

Output register containing the feature bits

features: int

value of output register, containing the feature bits

Since

1.5

DummyForceArrays (Object)

Not used by QMP; hack to let us use X86CPUFeatureWordInfoList internally

Members

unused: array of X86CPUFeatureWordInfo

Not documented

Since

2.5

NumaCpuOptions (Object)

Option “-numa cpu” overrides default cpu to node mapping. It accepts the same set of cpu properties as returned by query-hotpluggable-cpus[].props, where node-id could be used to override default node mapping.

Members

The members of CpuInstanceProperties

Since

2.10

HmatLBMemoryHierarchy (Enum)

The memory hierarchy in the System Locality Latency and Bandwidth Information Structure of HMAT (Heterogeneous Memory Attribute Table)

For more information about HmatLBMemoryHierarchy, see chapter 5.2.27.4: Table 5-146: Field “Flags” of ACPI 6.3 spec.

Values

memory

the structure represents the memory performance

first-level

first level of memory side cache

second-level

second level of memory side cache

third-level

third level of memory side cache

Since

5.0

HmatLBDataType (Enum)

Data type in the System Locality Latency and Bandwidth Information Structure of HMAT (Heterogeneous Memory Attribute Table)

For more information about HmatLBDataType, see chapter 5.2.27.4: Table 5-146: Field “Data Type” of ACPI 6.3 spec.

Values

access-latency

access latency (nanoseconds)

read-latency

read latency (nanoseconds)

write-latency

write latency (nanoseconds)

access-bandwidth

access bandwidth (Bytes per second)

read-bandwidth

read bandwidth (Bytes per second)

write-bandwidth

write bandwidth (Bytes per second)

Since

5.0

NumaHmatLBOptions (Object)

Set the system locality latency and bandwidth information between Initiator and Target proximity Domains.

For more information about NumaHmatLBOptions, see chapter 5.2.27.4: Table 5-146 of ACPI 6.3 spec.

Members

initiator: int

the Initiator Proximity Domain.

target: int

the Target Proximity Domain.

hierarchy: HmatLBMemoryHierarchy

the Memory Hierarchy. Indicates the performance of memory or side cache.

data-type: HmatLBDataType

presents the type of data, access/read/write latency or hit latency.

latency: int (optional)

the value of latency from initiator to target proximity domain, the latency unit is “ns(nanosecond)”.

bandwidth: int (optional)

the value of bandwidth between initiator and target proximity domain, the bandwidth unit is “Bytes per second”.

Since

5.0

HmatCacheAssociativity (Enum)

Cache associativity in the Memory Side Cache Information Structure of HMAT

For more information of HmatCacheAssociativity, see chapter 5.2.27.5: Table 5-147 of ACPI 6.3 spec.

Values

none

None (no memory side cache in this proximity domain, or cache associativity unknown)

direct

Direct Mapped

complex

Complex Cache Indexing (implementation specific)

Since

5.0

HmatCacheWritePolicy (Enum)

Cache write policy in the Memory Side Cache Information Structure of HMAT

For more information of HmatCacheWritePolicy, see chapter 5.2.27.5: Table 5-147: Field “Cache Attributes” of ACPI 6.3 spec.

Values

none

None (no memory side cache in this proximity domain, or cache write policy unknown)

write-back

Write Back (WB)

write-through

Write Through (WT)

Since

5.0

NumaHmatCacheOptions (Object)

Set the memory side cache information for a given memory domain.

For more information of NumaHmatCacheOptions, see chapter 5.2.27.5: Table 5-147: Field “Cache Attributes” of ACPI 6.3 spec.

Members

node-id: int

the memory proximity domain to which the memory belongs.

size: int

the size of memory side cache in bytes.

level: int

the cache level described in this structure.

associativity: HmatCacheAssociativity

the cache associativity, none/direct-mapped/complex(complex cache indexing).

policy: HmatCacheWritePolicy

the write policy, none/write-back/write-through.

line: int

the cache Line size in bytes.

Since

5.0

memsave (Command)

Save a portion of guest memory to a file.

Arguments

val: int

the virtual address of the guest to start from

size: int

the size of memory region to save

filename: string

the file to save the memory to as binary data

cpu-index: int (optional)

the index of the virtual CPU to use for translating the virtual address (defaults to CPU 0)

Since

0.14

Caution

Errors were not reliably returned until 1.1.

Example:

-> { "execute": "memsave",
     "arguments": { "val": 10,
                    "size": 100,
                    "filename": "/tmp/virtual-mem-dump" } }
<- { "return": {} }

pmemsave (Command)

Save a portion of guest physical memory to a file.

Arguments

val: int

the physical address of the guest to start from

size: int

the size of memory region to save

filename: string

the file to save the memory to as binary data

Since

0.14

Caution

Errors were not reliably returned until 1.1.

Example:

-> { "execute": "pmemsave",
     "arguments": { "val": 10,
                    "size": 100,
                    "filename": "/tmp/physical-mem-dump" } }
<- { "return": {} }

Memdev (Object)

Information about memory backend

Members

id: string (optional)

backend’s ID if backend has ‘id’ property (since 2.9)

size: int

memory backend size

merge: boolean

whether memory merge support is enabled

dump: boolean

whether memory backend’s memory is included in a core dump

prealloc: boolean

whether memory was preallocated

share: boolean

whether memory is private to QEMU or shared (since 6.1)

reserve: boolean (optional)

whether swap space (or huge pages) was reserved if applicable. This corresponds to the user configuration and not the actual behavior implemented in the OS to perform the reservation. For example, Linux will never reserve swap space for shared file mappings. (since 6.1)

host-nodes: array of int

host nodes for its memory policy

policy: HostMemPolicy

memory policy of memory backend

Since

2.1

query-memdev (Command)

Returns information for all memory backends.

Returns

a list of Memdev.

Since

2.1

Example:

-> { "execute": "query-memdev" }
<- { "return": [
       {
         "id": "mem1",
         "size": 536870912,
         "merge": false,
         "dump": true,
         "prealloc": false,
         "share": false,
         "host-nodes": [0, 1],
         "policy": "bind"
       },
       {
         "size": 536870912,
         "merge": false,
         "dump": true,
         "prealloc": true,
         "share": false,
         "host-nodes": [2, 3],
         "policy": "preferred"
       }
     ]
   }

CpuInstanceProperties (Object)

Properties identifying a CPU.

Which members are optional and which mandatory depends on the architecture and board.

For s390x see CPU topology on s390x.

The ids other than the node-id specify the position of the CPU within the CPU topology (as defined by the machine property “smp”, thus see also type SMPConfiguration)

Members

node-id: int (optional)

NUMA node ID the CPU belongs to

drawer-id: int (optional)

drawer number within CPU topology the CPU belongs to (since 8.2)

book-id: int (optional)

book number within parent container the CPU belongs to (since 8.2)

socket-id: int (optional)

socket number within parent container the CPU belongs to

die-id: int (optional)

die number within the parent container the CPU belongs to (since 4.1)

cluster-id: int (optional)

cluster number within the parent container the CPU belongs to (since 7.1)

module-id: int (optional)

module number within the parent container the CPU belongs to (since 9.1)

core-id: int (optional)

core number within the parent container the CPU belongs to

thread-id: int (optional)

thread number within the core the CPU belongs to

Since

2.7

HotpluggableCPU (Object)

Members

type: string

CPU object type for usage with device_add command

props: CpuInstanceProperties

list of properties to pass for hotplugging a CPU with device_add

vcpus-count: int

number of logical VCPU threads HotpluggableCPU provides

qom-path: string (optional)

link to existing CPU object if CPU is present or omitted if CPU is not present.

Note

Management should be prepared to pass through additional properties with device_add.

Since

2.7

query-hotpluggable-cpus (Command)

Returns

a list of HotpluggableCPU objects.

Since

2.7

Example:

For pseries machine type started with -smp 2,cores=2,maxcpus=4 -cpu POWER8:

-> { "execute": "query-hotpluggable-cpus" }
<- {"return": [
     { "props": { "core-id": 8 }, "type": "POWER8-spapr-cpu-core",
       "vcpus-count": 1 },
     { "props": { "core-id": 0 }, "type": "POWER8-spapr-cpu-core",
       "vcpus-count": 1, "qom-path": "/machine/unattached/device[0]"}
   ]}

Example:

For pc machine type started with -smp 1,maxcpus=2:

-> { "execute": "query-hotpluggable-cpus" }
<- {"return": [
     {
        "type": "qemu64-x86_64-cpu", "vcpus-count": 1,
        "props": {"core-id": 0, "socket-id": 1, "thread-id": 0}
     },
     {
        "qom-path": "/machine/unattached/device[0]",
        "type": "qemu64-x86_64-cpu", "vcpus-count": 1,
        "props": {"core-id": 0, "socket-id": 0, "thread-id": 0}
     }
   ]}

Example:

For s390x-virtio-ccw machine type started with -smp 1,maxcpus=2 -cpu qemu (Since: 2.11):

-> { "execute": "query-hotpluggable-cpus" }
<- {"return": [
     {
        "type": "qemu-s390x-cpu", "vcpus-count": 1,
        "props": { "core-id": 1 }
     },
     {
        "qom-path": "/machine/unattached/device[0]",
        "type": "qemu-s390x-cpu", "vcpus-count": 1,
        "props": { "core-id": 0 }
     }
   ]}

set-numa-node (Command)

Runtime equivalent of ‘-numa’ CLI option, available at preconfigure stage to configure numa mapping before initializing machine.

Arguments

The members of NumaOptions

Since

3.0

balloon (Command)

Request the balloon driver to change its balloon size.

Arguments

value: int

the target logical size of the VM in bytes. We can deduce the size of the balloon using this formula:

logical_vm_size = vm_ram_size - balloon_size

From it we have: balloon_size = vm_ram_size - value

Errors

• If the balloon driver is enabled but not functional because the KVM kernel module cannot support it, KVMMissingCap

• If no balloon device is present, DeviceNotActive

Note

This command just issues a request to the guest. When it returns, the balloon size may not have changed. A guest can change the balloon size independent of this command.

Since

0.14

Example:

-> { "execute": "balloon", "arguments": { "value": 536870912 } }
<- { "return": {} }

With a 2.5GiB guest this command inflated the ballon to 3GiB.

BalloonInfo (Object)

Information about the guest balloon device.

Members

actual: int

the logical size of the VM in bytes Formula used: logical_vm_size = vm_ram_size - balloon_size

Since

0.14

query-balloon (Command)

Return information about the balloon device.

Returns

BalloonInfo

Errors

• If the balloon driver is enabled but not functional because the KVM kernel module cannot support it, KVMMissingCap

• If no balloon device is present, DeviceNotActive

Since

0.14

Example:

-> { "execute": "query-balloon" }
<- { "return": {
         "actual": 1073741824
      }
   }

BALLOON_CHANGE (Event)

Emitted when the guest changes the actual BALLOON level. This value is equivalent to the actual field return by the ‘query-balloon’ command

Arguments

actual: int

the logical size of the VM in bytes Formula used: logical_vm_size = vm_ram_size - balloon_size

Note

This event is rate-limited.

Since

1.2

Example:

<- { "event": "BALLOON_CHANGE",
     "data": { "actual": 944766976 },
     "timestamp": { "seconds": 1267020223, "microseconds": 435656 } }

HvBalloonInfo (Object)

hv-balloon guest-provided memory status information.

Members

committed: int

the amount of memory in use inside the guest plus the amount of the memory unusable inside the guest (ballooned out, offline, etc.)

available: int

the amount of the memory inside the guest available for new allocations (“free”)

Since

8.2

query-hv-balloon-status-report (Command)

Returns the hv-balloon driver data contained in the last received “STATUS” message from the guest.

Returns

HvBalloonInfo

Errors

• If no hv-balloon device is present, guest memory status reporting is not enabled or no guest memory status report received yet, GenericError

Since

8.2

Example:

-> { "execute": "query-hv-balloon-status-report" }
<- { "return": {
         "committed": 816640000,
         "available": 3333054464
      }
   }

HV_BALLOON_STATUS_REPORT (Event)

Emitted when the hv-balloon driver receives a “STATUS” message from the guest.

Note

This event is rate-limited.

Arguments

The members of HvBalloonInfo

Since

8.2

Example:

<- { "event": "HV_BALLOON_STATUS_REPORT",
     "data": { "committed": 816640000, "available": 3333054464 },
     "timestamp": { "seconds": 1600295492, "microseconds": 661044 } }

MemoryInfo (Object)

Actual memory information in bytes.

Members

base-memory: int

size of “base” memory specified with command line option -m.

plugged-memory: int (optional)

size of memory that can be hot-unplugged. This field is omitted if target doesn’t support memory hotplug (i.e. CONFIG_MEM_DEVICE not defined at build time).

Since

2.11

query-memory-size-summary (Command)

Return the amount of initially allocated and present hotpluggable (if enabled) memory in bytes.

Example:

-> { "execute": "query-memory-size-summary" }
<- { "return": { "base-memory": 4294967296, "plugged-memory": 0 } }

Since

2.11

PCDIMMDeviceInfo (Object)

PCDIMMDevice state information

Members

id: string (optional)

device’s ID

addr: int

physical address, where device is mapped

size: int

size of memory that the device provides

slot: int

slot number at which device is plugged in

node: int

NUMA node number where device is plugged in

memdev: string

memory backend linked with device

hotplugged: boolean

true if device was hotplugged

hotpluggable: boolean

true if device if could be added/removed while machine is running

Since

2.1

VirtioPMEMDeviceInfo (Object)

VirtioPMEM state information

Members

id: string (optional)

device’s ID

memaddr: int

physical address in memory, where device is mapped

size: int

size of memory that the device provides

memdev: string

memory backend linked with device

Since

4.1

VirtioMEMDeviceInfo (Object)

VirtioMEMDevice state information

Members

id: string (optional)

device’s ID

memaddr: int

physical address in memory, where device is mapped

requested-size: int

the user requested size of the device

size: int

the (current) size of memory that the device provides

max-size: int

the maximum size of memory that the device can provide

block-size: int

the block size of memory that the device provides

node: int

NUMA node number where device is assigned to

memdev: string

memory backend linked with the region

Since

5.1

SgxEPCDeviceInfo (Object)

Sgx EPC state information

Members

id: string (optional)

device’s ID

memaddr: int

physical address in memory, where device is mapped

size: int

size of memory that the device provides

memdev: string

memory backend linked with device

node: int

the numa node (Since: 7.0)

Since

6.2

HvBalloonDeviceInfo (Object)

hv-balloon provided memory state information

Members

id: string (optional)

device’s ID

memaddr: int (optional)

physical address in memory, where device is mapped

max-size: int

the maximum size of memory that the device can provide

memdev: string (optional)

memory backend linked with device

Since

8.2

MemoryDeviceInfoKind (Enum)

Values

nvdimm

since 2.12

virtio-pmem

since 4.1

virtio-mem

since 5.1

sgx-epc

since 6.2.

hv-balloon

since 8.2.

dimm

Not documented

Since

2.1

PCDIMMDeviceInfoWrapper (Object)

Members

data: PCDIMMDeviceInfo

PCDIMMDevice state information

Since

2.1

VirtioPMEMDeviceInfoWrapper (Object)

Members

data: VirtioPMEMDeviceInfo

VirtioPMEM state information

Since

2.1

VirtioMEMDeviceInfoWrapper (Object)

Members

data: VirtioMEMDeviceInfo

VirtioMEMDevice state information

Since

2.1

SgxEPCDeviceInfoWrapper (Object)

Members

data: SgxEPCDeviceInfo

Sgx EPC state information

Since

6.2

HvBalloonDeviceInfoWrapper (Object)

Members

data: HvBalloonDeviceInfo

hv-balloon provided memory state information

Since

8.2

MemoryDeviceInfo (Object)

Union containing information about a memory device

Members

type: MemoryDeviceInfoKind

memory device type

The members of PCDIMMDeviceInfoWrapper when type is "dimm"

The members of PCDIMMDeviceInfoWrapper when type is "nvdimm"

The members of VirtioPMEMDeviceInfoWrapper when type is "virtio-pmem"

The members of VirtioMEMDeviceInfoWrapper when type is "virtio-mem"

The members of SgxEPCDeviceInfoWrapper when type is "sgx-epc"

The members of HvBalloonDeviceInfoWrapper when type is "hv-balloon"

Since

2.1

SgxEPC (Object)

Sgx EPC cmdline information

Members

memdev: string

memory backend linked with device

node: int

the numa node (Since: 7.0)

Since

6.2

SgxEPCProperties (Object)

SGX properties of machine types.

Members

sgx-epc: array of SgxEPC

list of ids of memory-backend-epc objects.

Since

6.2

query-memory-devices (Command)

Lists available memory devices and their state

Since

2.1

Example:

-> { "execute": "query-memory-devices" }
<- { "return": [ { "data":
                      { "addr": 5368709120,
                        "hotpluggable": true,
                        "hotplugged": true,
                        "id": "d1",
                        "memdev": "/objects/memX",
                        "node": 0,
                        "size": 1073741824,
                        "slot": 0},
                   "type": "dimm"
                 } ] }

MEMORY_DEVICE_SIZE_CHANGE (Event)

Emitted when the size of a memory device changes. Only emitted for memory devices that can actually change the size (e.g., virtio-mem due to guest action).

Arguments

id: string (optional)

device’s ID

size: int

the new size of memory that the device provides

qom-path: string

path to the device object in the QOM tree (since 6.2)

Note

This event is rate-limited.

Since

5.1

Example:

<- { "event": "MEMORY_DEVICE_SIZE_CHANGE",
     "data": { "id": "vm0", "size": 1073741824,
               "qom-path": "/machine/unattached/device[2]" },
     "timestamp": { "seconds": 1588168529, "microseconds": 201316 } }

BootConfiguration (Object)

Schema for virtual machine boot configuration.

Members

order: string (optional)

Boot order (a=floppy, c=hard disk, d=CD-ROM, n=network)

once: string (optional)

Boot order to apply on first boot

menu: boolean (optional)

Whether to show a boot menu

splash: string (optional)

The name of the file to be passed to the firmware as logo picture, if menu is true.

splash-time: int (optional)

How long to show the logo picture, in milliseconds

reboot-timeout: int (optional)

Timeout before guest reboots after boot fails

strict: boolean (optional)

Whether to attempt booting from devices not included in the boot order

Since

7.1

SMPConfiguration (Object)

Schema for CPU topology configuration. A missing value lets QEMU figure out a suitable value based on the ones that are provided.

The members other than cpus and maxcpus define a topology of containers.

The ordering from highest/coarsest to lowest/finest is: drawers, books, sockets, dies, clusters, cores, threads.

Different architectures support different subsets of topology containers.

For example, s390x does not have clusters and dies, and the socket is the parent container of cores.

Members

cpus: int (optional)

number of virtual CPUs in the virtual machine

maxcpus: int (optional)

maximum number of hotpluggable virtual CPUs in the virtual machine

drawers: int (optional)

number of drawers in the CPU topology (since 8.2)

books: int (optional)

number of books in the CPU topology (since 8.2)

sockets: int (optional)

number of sockets per parent container

dies: int (optional)

number of dies per parent container

clusters: int (optional)

number of clusters per parent container (since 7.0)

modules: int (optional)

number of modules per parent container (since 9.1)

cores: int (optional)

number of cores per parent container

threads: int (optional)

number of threads per core

Since

6.1

x-query-irq (Command)

Query interrupt statistics

Features

unstable

This command is meant for debugging.

Returns

interrupt statistics

Since

6.2

x-query-jit (Command)

Query TCG compiler statistics

Features

unstable

This command is meant for debugging.

Returns

TCG compiler statistics

Since

6.2

If

CONFIG_TCG

x-query-numa (Command)

Query NUMA topology information

Features

unstable

This command is meant for debugging.

Returns

topology information

Since

6.2

x-query-opcount (Command)

Query TCG opcode counters

Features

unstable

This command is meant for debugging.

Returns

TCG opcode counters

Since

6.2

If

CONFIG_TCG

x-query-ramblock (Command)

Query system ramblock information

Features

unstable

This command is meant for debugging.

Returns

system ramblock information

Since

6.2

x-query-roms (Command)

Query information on the registered ROMS

Features

unstable

This command is meant for debugging.

Returns

registered ROMs

Since

6.2

x-query-usb (Command)

Query information on the USB devices

Features

unstable

This command is meant for debugging.

Returns

USB device information

Since

6.2

SmbiosEntryPointType (Enum)

Values

32

SMBIOS version 2.1 (32-bit) Entry Point

64

SMBIOS version 3.0 (64-bit) Entry Point

auto

Either 2.x or 3.x SMBIOS version, 2.x if configuration can be described by it and 3.x otherwise (since: 9.0)

Since

7.0

MemorySizeConfiguration (Object)

Schema for memory size configuration.

Members

size: int (optional)

memory size in bytes

max-size: int (optional)

maximum hotpluggable memory size in bytes

slots: int (optional)

number of available memory slots for hotplug

Since

7.1

dumpdtb (Command)

Save the FDT in dtb format.

Arguments

filename: string

name of the dtb file to be created

Since

7.2

Example:

-> { "execute": "dumpdtb" }
     "arguments": { "filename": "fdt.dtb" } }
<- { "return": {} }

If

CONFIG_FDT

x-query-interrupt-controllers (Command)

Query information on interrupt controller devices

Features

unstable

This command is meant for debugging.

Returns

Interrupt controller devices information

Since

9.1

CpuModelInfo (Object)

Virtual CPU model.

A CPU model consists of the name of a CPU definition, to which delta changes are applied (e.g. features added/removed). Most magic values that an architecture might require should be hidden behind the name. However, if required, architectures can expose relevant properties.

Members

name: string

the name of the CPU definition the model is based on

props: value (optional)

a dictionary of QOM properties to be applied

Since

2.8

CpuModelExpansionType (Enum)

An enumeration of CPU model expansion types.

Values

static

Expand to a static CPU model, a combination of a static base model name and property delta changes. As the static base model will never change, the expanded CPU model will be the same, independent of QEMU version, machine type, machine options, and accelerator options. Therefore, the resulting model can be used by tooling without having to specify a compatibility machine - e.g. when displaying the “host” model. The static CPU models are migration-safe.

full

Expand all properties. The produced model is not guaranteed to be migration-safe, but allows tooling to get an insight and work with model details.

Note

When a non-migration-safe CPU model is expanded in static mode, some features enabled by the CPU model may be omitted, because they can’t be implemented by a static CPU model definition (e.g. cache info passthrough and PMU passthrough in x86). If you need an accurate representation of the features enabled by a non-migration-safe CPU model, use full. If you need a static representation that will keep ABI compatibility even when changing QEMU version or machine-type, use static (but keep in mind that some features may be omitted).

Since

2.8

CpuModelCompareResult (Enum)

An enumeration of CPU model comparison results. The result is usually calculated using e.g. CPU features or CPU generations.

Values

incompatible

If model A is incompatible to model B, model A is not guaranteed to run where model B runs and the other way around.

identical

If model A is identical to model B, model A is guaranteed to run where model B runs and the other way around.

superset

If model A is a superset of model B, model B is guaranteed to run where model A runs. There are no guarantees about the other way.

subset

If model A is a subset of model B, model A is guaranteed to run where model B runs. There are no guarantees about the other way.

Since

2.8

CpuModelBaselineInfo (Object)

The result of a CPU model baseline.

Members

model: CpuModelInfo

the baselined CpuModelInfo.

Since

2.8

If

TARGET_S390X

CpuModelCompareInfo (Object)

The result of a CPU model comparison.

Members

result: CpuModelCompareResult

The result of the compare operation.

responsible-properties: array of string

List of properties that led to the comparison result not being identical.

responsible-properties is a list of QOM property names that led to both CPUs not being detected as identical. For identical models, this list is empty. If a QOM property is read-only, that means there’s no known way to make the CPU models identical. If the special property name “type” is included, the models are by definition not identical and cannot be made identical.

Since

2.8

If

TARGET_S390X

query-cpu-model-comparison (Command)

Compares two CPU models, modela and modelb, returning how they compare in a specific configuration. The results indicates how both models compare regarding runnability. This result can be used by tooling to make decisions if a certain CPU model will run in a certain configuration or if a compatible CPU model has to be created by baselining.

Usually, a CPU model is compared against the maximum possible CPU model of a certain configuration (e.g. the “host” model for KVM). If that CPU model is identical or a subset, it will run in that configuration.

The result returned by this command may be affected by:

• QEMU version: CPU models may look different depending on the QEMU version. (Except for CPU models reported as “static” in query-cpu-definitions.)

• machine-type: CPU model may look different depending on the machine-type. (Except for CPU models reported as “static” in query-cpu-definitions.)

• machine options (including accelerator): in some architectures, CPU models may look different depending on machine and accelerator options. (Except for CPU models reported as “static” in query-cpu-definitions.)

• “-cpu” arguments and global properties: arguments to the -cpu option and global properties may affect expansion of CPU models. Using query-cpu-model-expansion while using these is not advised.

Some architectures may not support comparing CPU models. s390x supports comparing CPU models.

Arguments

modela: CpuModelInfo

description of the first CPU model to compare, referred to as “model A” in CpuModelCompareResult

modelb: CpuModelInfo

description of the second CPU model to compare, referred to as “model B” in CpuModelCompareResult

Returns

a CpuModelCompareInfo describing how both CPU models compare

Errors

• if comparing CPU models is not supported

• if a model cannot be used

• if a model contains an unknown cpu definition name, unknown properties or properties with wrong types.

Note

This command isn’t specific to s390x, but is only implemented on this architecture currently.

Since

2.8

If

TARGET_S390X

query-cpu-model-baseline (Command)

Baseline two CPU models, modela and modelb, creating a compatible third model. The created model will always be a static, migration-safe CPU model (see “static” CPU model expansion for details).

This interface can be used by tooling to create a compatible CPU model out two CPU models. The created CPU model will be identical to or a subset of both CPU models when comparing them. Therefore, the created CPU model is guaranteed to run where the given CPU models run.

The result returned by this command may be affected by:

• QEMU version: CPU models may look different depending on the QEMU version. (Except for CPU models reported as “static” in query-cpu-definitions.)

• machine-type: CPU model may look different depending on the machine-type. (Except for CPU models reported as “static” in query-cpu-definitions.)

• machine options (including accelerator): in some architectures, CPU models may look different depending on machine and accelerator options. (Except for CPU models reported as “static” in query-cpu-definitions.)

• “-cpu” arguments and global properties: arguments to the -cpu option and global properties may affect expansion of CPU models. Using query-cpu-model-expansion while using these is not advised.

Some architectures may not support baselining CPU models. s390x supports baselining CPU models.

Arguments

modela: CpuModelInfo

description of the first CPU model to baseline

modelb: CpuModelInfo

description of the second CPU model to baseline

Returns

a CpuModelBaselineInfo describing the baselined CPU model

Errors

• if baselining CPU models is not supported

• if a model cannot be used

• if a model contains an unknown cpu definition name, unknown properties or properties with wrong types.

Note

This command isn’t specific to s390x, but is only implemented on this architecture currently.

Since

2.8

If

TARGET_S390X

CpuModelExpansionInfo (Object)

The result of a cpu model expansion.

Members

model: CpuModelInfo

the expanded CpuModelInfo.

deprecated-props: array of string (If: TARGET_S390X)

a list of properties that are flagged as deprecated by the CPU vendor. The list depends on the CpuModelExpansionType: “static” properties are a subset of the enabled-properties for the expanded model; “full” properties are a set of properties that are deprecated across all models for the architecture. (since: 9.1).

Since

2.8

If

TARGET_S390X or TARGET_I386 or TARGET_ARM or TARGET_LOONGARCH64 or TARGET_RISCV

query-cpu-model-expansion (Command)

Expands a given CPU model, model, (or a combination of CPU model + additional options) to different granularities, specified by type, allowing tooling to get an understanding what a specific CPU model looks like in QEMU under a certain configuration.

This interface can be used to query the “host” CPU model.

The data returned by this command may be affected by:

• QEMU version: CPU models may look different depending on the QEMU version. (Except for CPU models reported as “static” in query-cpu-definitions.)

• machine-type: CPU model may look different depending on the machine-type. (Except for CPU models reported as “static” in query-cpu-definitions.)

• machine options (including accelerator): in some architectures, CPU models may look different depending on machine and accelerator options. (Except for CPU models reported as “static” in query-cpu-definitions.)

• “-cpu” arguments and global properties: arguments to the -cpu option and global properties may affect expansion of CPU models. Using query-cpu-model-expansion while using these is not advised.

Some architectures may not support all expansion types. s390x supports “full” and “static”. Arm only supports “full”.

Arguments

model: CpuModelInfo

description of the CPU model to expand

type: CpuModelExpansionType

expansion type, specifying how to expand the CPU model

Returns

a CpuModelExpansionInfo describing the expanded CPU model

Errors

• if expanding CPU models is not supported

• if the model cannot be expanded

• if the model contains an unknown CPU definition name, unknown properties or properties with a wrong type

• if an expansion type is not supported

Since

2.8

If

TARGET_S390X or TARGET_I386 or TARGET_ARM or TARGET_LOONGARCH64 or TARGET_RISCV

CpuDefinitionInfo (Object)

Virtual CPU definition.

Members

name: string

the name of the CPU definition

migration-safe: boolean (optional)

whether a CPU definition can be safely used for migration in combination with a QEMU compatibility machine when migrating between different QEMU versions and between hosts with different sets of (hardware or software) capabilities. If not provided, information is not available and callers should not assume the CPU definition to be migration-safe. (since 2.8)

static: boolean

whether a CPU definition is static and will not change depending on QEMU version, machine type, machine options and accelerator options. A static model is always migration-safe. (since 2.8)

unavailable-features: array of string (optional)

List of properties that prevent the CPU model from running in the current host. (since 2.8)

typename: string

Type name that can be used as argument to device-list-properties, to introspect properties configurable using -cpu or -global. (since 2.9)

alias-of: string (optional)

Name of CPU model this model is an alias for. The target of the CPU model alias may change depending on the machine type. Management software is supposed to translate CPU model aliases in the VM configuration, because aliases may stop being migration-safe in the future (since 4.1)

deprecated: boolean

If true, this CPU model is deprecated and may be removed in in some future version of QEMU according to the QEMU deprecation policy. (since 5.2)

unavailable-features is a list of QOM property names that represent CPU model attributes that prevent the CPU from running. If the QOM property is read-only, that means there’s no known way to make the CPU model run in the current host. Implementations that choose not to provide specific information return the property name “type”. If the property is read-write, it means that it MAY be possible to run the CPU model in the current host if that property is changed. Management software can use it as hints to suggest or choose an alternative for the user, or just to generate meaningful error messages explaining why the CPU model can’t be used. If unavailable-features is an empty list, the CPU model is runnable using the current host and machine-type. If unavailable-features is not present, runnability information for the CPU is not available.

Since

1.2

If

TARGET_PPC or TARGET_ARM or TARGET_I386 or TARGET_S390X or TARGET_MIPS or TARGET_LOONGARCH64 or TARGET_RISCV

query-cpu-definitions (Command)

Return a list of supported virtual CPU definitions

Returns

a list of CpuDefinitionInfo

Since

1.2

If

TARGET_PPC or TARGET_ARM or TARGET_I386 or TARGET_S390X or TARGET_MIPS or TARGET_LOONGARCH64 or TARGET_RISCV

S390CpuPolarization (Enum)

An enumeration of CPU polarization that can be assumed by a virtual S390 CPU

Values

horizontal

Not documented

vertical

Not documented

Since

8.2

If

TARGET_S390X

set-cpu-topology (Command)

Modify the topology by moving the CPU inside the topology tree, or by changing a modifier attribute of a CPU. Absent values will not be modified.

Arguments

core-id: int

the vCPU ID to be moved

socket-id: int (optional)

destination socket to move the vCPU to

book-id: int (optional)

destination book to move the vCPU to

drawer-id: int (optional)

destination drawer to move the vCPU to

entitlement: S390CpuEntitlement (optional)

entitlement to set

dedicated: boolean (optional)

whether the provisioning of real to virtual CPU is dedicated

Features

unstable

This command is experimental.

Since

8.2

If

TARGET_S390X and CONFIG_KVM

CPU_POLARIZATION_CHANGE (Event)

Emitted when the guest asks to change the polarization.

The guest can tell the host (via the PTF instruction) whether the CPUs should be provisioned using horizontal or vertical polarization.

On horizontal polarization the host is expected to provision all vCPUs equally.

On vertical polarization the host can provision each vCPU differently. The guest will get information on the details of the provisioning the next time it uses the STSI(15) instruction.

Arguments

polarization: S390CpuPolarization

polarization specified by the guest

Features

unstable

This event is experimental.

Since

8.2

Example:

<- { "event": "CPU_POLARIZATION_CHANGE",
     "data": { "polarization": "horizontal" },
     "timestamp": { "seconds": 1401385907, "microseconds": 422329 } }

If

TARGET_S390X and CONFIG_KVM

CpuPolarizationInfo (Object)

The result of a CPU polarization query.

Members

polarization: S390CpuPolarization

the CPU polarization

Since

8.2

If

TARGET_S390X and CONFIG_KVM

query-s390x-cpu-polarization (Command)

Features

unstable

This command is experimental.

Returns

the machine’s CPU polarization

Since

8.2

If

TARGET_S390X and CONFIG_KVM

Record/replay

ReplayMode (Enum)

Mode of the replay subsystem.

Values

none

normal execution mode. Replay or record are not enabled.

record

record mode. All non-deterministic data is written into the replay log.

play

replay mode. Non-deterministic data required for system execution is read from the log.

Since

2.5

ReplayInfo (Object)

Record/replay information.

Members

mode: ReplayMode

current mode.

filename: string (optional)

name of the record/replay log file. It is present only in record or replay modes, when the log is recorded or replayed.

icount: int

current number of executed instructions.

Since

5.2

query-replay (Command)

Retrieve the record/replay information. It includes current instruction count which may be used for replay-break and replay-seek commands.

Returns

record/replay information.

Since

5.2

Example:

-> { "execute": "query-replay" }
<- { "return": { "mode": "play", "filename": "log.rr", "icount": 220414 } }

replay-break (Command)

Set replay breakpoint at instruction count icount. Execution stops when the specified instruction is reached. There can be at most one breakpoint. When breakpoint is set, any prior one is removed. The breakpoint may be set only in replay mode and only “in the future”, i.e. at instruction counts greater than the current one. The current instruction count can be observed with query-replay.

Arguments

icount: int

instruction count to stop at

Since

5.2

Example:

-> { "execute": "replay-break", "arguments": { "icount": 220414 } }
<- { "return": {} }

replay-delete-break (Command)

Remove replay breakpoint which was set with replay-break. The command is ignored when there are no replay breakpoints.

Since

5.2

Example:

-> { "execute": "replay-delete-break" }
<- { "return": {} }

replay-seek (Command)

Automatically proceed to the instruction count icount, when replaying the execution. The command automatically loads nearest snapshot and replays the execution to find the desired instruction. When there is no preceding snapshot or the execution is not replayed, then the command fails. Instruction count can be obtained with the query-replay command.

Arguments

icount: int

target instruction count

Since

5.2

Example:

-> { "execute": "replay-seek", "arguments": { "icount": 220414 } }
<- { "return": {} }

Yank feature

YankInstanceType (Enum)

An enumeration of yank instance types. See YankInstance for more information.

Values

block-node

Not documented

chardev

Not documented

migration

Not documented

Since

6.0

YankInstanceBlockNode (Object)

Specifies which block graph node to yank. See YankInstance for more information.

Members

node-name: string

the name of the block graph node

Since

6.0

YankInstanceChardev (Object)

Specifies which character device to yank. See YankInstance for more information.

Members

id: string

the chardev’s ID

Since

6.0

YankInstance (Object)

A yank instance can be yanked with the yank qmp command to recover from a hanging QEMU.

Members

type: YankInstanceType

yank instance type

The members of YankInstanceBlockNode when type is "block-node"

The members of YankInstanceChardev when type is "chardev"

Currently implemented yank instances:

• nbd block device: Yanking it will shut down the connection to the nbd server without attempting to reconnect.

• socket chardev: Yanking it will shut down the connected socket.

• migration: Yanking it will shut down all migration connections. Unlike migrate_cancel, it will not notify the migration process, so migration will go into failed state, instead of cancelled state. yank should be used to recover from hangs.

Since

6.0

yank (Command)

Try to recover from hanging QEMU by yanking the specified instances. See YankInstance for more information.

Arguments

instances: array of YankInstance

the instances to be yanked

Errors

• If any of the YankInstances doesn’t exist, DeviceNotFound

Example:

-> { "execute": "yank",
     "arguments": {
         "instances": [
              { "type": "block-node",
                "node-name": "nbd0" }
         ] } }
<- { "return": {} }

Since

6.0

query-yank (Command)

Query yank instances. See YankInstance for more information.

Returns

list of YankInstance

Example:

-> { "execute": "query-yank" }
<- { "return": [
         { "type": "block-node",
           "node-name": "nbd0" }
     ] }

Since

6.0

Miscellanea

add_client (Command)

Allow client connections for VNC, Spice and socket based character devices to be passed in to QEMU via SCM_RIGHTS.

If the FD associated with fdname is not a socket, the command will fail and the FD will be closed.

Arguments

protocol: string

protocol name. Valid names are “vnc”, “spice”, “dbus-display” or the name of a character device (e.g. from -chardev id=XXXX)

fdname: string

file descriptor name previously passed via ‘getfd’ command

skipauth: boolean (optional)

whether to skip authentication. Only applies to “vnc” and “spice” protocols

tls: boolean (optional)

whether to perform TLS. Only applies to the “spice” protocol

Since

0.14

Example:

-> { "execute": "add_client", "arguments": { "protocol": "vnc",
                                             "fdname": "myclient" } }
<- { "return": {} }

NameInfo (Object)

Guest name information.

Members

name: string (optional)

The name of the guest

Since

0.14

query-name (Command)

Return the name information of a guest.

Returns

NameInfo of the guest

Since

0.14

Example:

-> { "execute": "query-name" }
<- { "return": { "name": "qemu-name" } }

IOThreadInfo (Object)

Information about an iothread

Members

id: string

the identifier of the iothread

thread-id: int

ID of the underlying host thread

poll-max-ns: int

maximum polling time in ns, 0 means polling is disabled (since 2.9)

poll-grow: int

how many ns will be added to polling time, 0 means that it’s not configured (since 2.9)

poll-shrink: int

how many ns will be removed from polling time, 0 means that it’s not configured (since 2.9)

aio-max-batch: int

maximum number of requests in a batch for the AIO engine, 0 means that the engine will use its default (since 6.1)

Since

2.0

query-iothreads (Command)

Returns a list of information about each iothread.

Note

This list excludes the QEMU main loop thread, which is not declared using the -object iothread command-line option. It is always the main thread of the process.

Returns

a list of IOThreadInfo for each iothread

Since

2.0

Example:

-> { "execute": "query-iothreads" }
<- { "return": [
         {
            "id":"iothread0",
            "thread-id":3134
         },
         {
            "id":"iothread1",
            "thread-id":3135
         }
      ]
   }

stop (Command)

Stop guest VM execution.

Since

0.14

Note

This function will succeed even if the guest is already in the stopped state. In “inmigrate” state, it will ensure that the guest remains paused once migration finishes, as if the -S option was passed on the command line.

In the “suspended” state, it will completely stop the VM and cause a transition to the “paused” state. (Since 9.0)

Example:

-> { "execute": "stop" }
<- { "return": {} }

cont (Command)

Resume guest VM execution.

Since

0.14

Note

This command will succeed if the guest is currently running. It will also succeed if the guest is in the “inmigrate” state; in this case, the effect of the command is to make sure the guest starts once migration finishes, removing the effect of the -S command line option if it was passed.

If the VM was previously suspended, and not been reset or woken, this command will transition back to the “suspended” state. (Since 9.0)

Example:

-> { "execute": "cont" }
<- { "return": {} }

x-exit-preconfig (Command)

Exit from “preconfig” state

This command makes QEMU exit the preconfig state and proceed with VM initialization using configuration data provided on the command line and via the QMP monitor during the preconfig state. The command is only available during the preconfig state (i.e. when the –preconfig command line option was in use).

Features

unstable

This command is experimental.

Since

3.0

Example:

-> { "execute": "x-exit-preconfig" }
<- { "return": {} }

human-monitor-command (Command)

Execute a command on the human monitor and return the output.

Arguments

command-line: string

the command to execute in the human monitor

cpu-index: int (optional)

The CPU to use for commands that require an implicit CPU

Features

savevm-monitor-nodes

If present, HMP command savevm only snapshots monitor-owned nodes if they have no parents. This allows the use of ‘savevm’ with -blockdev. (since 4.2)

Returns

the output of the command as a string

Since

0.14

Note

This command only exists as a stop-gap. Its use is highly discouraged. The semantics of this command are not guaranteed: this means that command names, arguments and responses can change or be removed at ANY time. Applications that rely on long term stability guarantees should NOT use this command.

Known limitations:

• This command is stateless, this means that commands that depend on state information (such as getfd) might not work.

• Commands that prompt the user for data don’t currently work.

Example:

-> { "execute": "human-monitor-command",
     "arguments": { "command-line": "info kvm" } }
<- { "return": "kvm support: enabled\r\n" }

getfd (Command)

Receive a file descriptor via SCM rights and assign it a name

Arguments

fdname: string

file descriptor name

Since

0.14

Note

If fdname already exists, the file descriptor assigned to it will be closed and replaced by the received file descriptor.

The ‘closefd’ command can be used to explicitly close the file descriptor when it is no longer needed.

Example:

-> { "execute": "getfd", "arguments": { "fdname": "fd1" } }
<- { "return": {} }

If

CONFIG_POSIX

get-win32-socket (Command)

Add a socket that was duplicated to QEMU process with WSADuplicateSocketW() via WSASocket() & WSAPROTOCOL_INFOW structure and assign it a name (the SOCKET is associated with a CRT file descriptor)

Arguments

info: string

the WSAPROTOCOL_INFOW structure (encoded in base64)

fdname: string

file descriptor name

Since

8.0

Note

If fdname already exists, the file descriptor assigned to it will be closed and replaced by the received file descriptor.

The ‘closefd’ command can be used to explicitly close the file descriptor when it is no longer needed.

Example:

-> { "execute": "get-win32-socket",
     "arguments": { "info": "abcd123..", "fdname": "skclient" } }
<- { "return": {} }

If

CONFIG_WIN32

closefd (Command)

Close a file descriptor previously passed via SCM rights

Arguments

fdname: string

file descriptor name

Since

0.14

Example:

-> { "execute": "closefd", "arguments": { "fdname": "fd1" } }
<- { "return": {} }

AddfdInfo (Object)

Information about a file descriptor that was added to an fd set.

Members

fdset-id: int

The ID of the fd set that fd was added to.

fd: int

The file descriptor that was received via SCM rights and added to the fd set.

Since

1.2

add-fd (Command)

Add a file descriptor, that was passed via SCM rights, to an fd set.

Arguments

fdset-id: int (optional)

The ID of the fd set to add the file descriptor to.

opaque: string (optional)

A free-form string that can be used to describe the fd.

Returns

AddfdInfo

Errors

• If file descriptor was not received, GenericError

• If fdset-id is a negative value, GenericError

Note

The list of fd sets is shared by all monitor connections.

Note

If fdset-id is not specified, a new fd set will be created.

Since

1.2

Example:

-> { "execute": "add-fd", "arguments": { "fdset-id": 1 } }
<- { "return": { "fdset-id": 1, "fd": 3 } }

remove-fd (Command)

Remove a file descriptor from an fd set.

Arguments

fdset-id: int

The ID of the fd set that the file descriptor belongs to.

fd: int (optional)

The file descriptor that is to be removed.

Errors

• If fdset-id or fd is not found, GenericError

Since

1.2

Note

The list of fd sets is shared by all monitor connections.

Note

If fd is not specified, all file descriptors in fdset-id will be removed.

Example:

-> { "execute": "remove-fd", "arguments": { "fdset-id": 1, "fd": 3 } }
<- { "return": {} }

FdsetFdInfo (Object)

Information about a file descriptor that belongs to an fd set.

Members

fd: int

The file descriptor value.

opaque: string (optional)

A free-form string that can be used to describe the fd.

Since

1.2

FdsetInfo (Object)

Information about an fd set.

Members

fdset-id: int

The ID of the fd set.

fds: array of FdsetFdInfo

A list of file descriptors that belong to this fd set.

Since

1.2

query-fdsets (Command)

Return information describing all fd sets.

Returns

A list of FdsetInfo

Since

1.2

Note

The list of fd sets is shared by all monitor connections.

Example:

-> { "execute": "query-fdsets" }
<- { "return": [
       {
         "fds": [
           {
             "fd": 30,
             "opaque": "rdonly:/path/to/file"
           },
           {
             "fd": 24,
             "opaque": "rdwr:/path/to/file"
           }
         ],
         "fdset-id": 1
       },
       {
         "fds": [
           {
             "fd": 28
           },
           {
             "fd": 29
           }
         ],
         "fdset-id": 0
       }
     ]
   }

CommandLineParameterType (Enum)

Possible types for an option parameter.

Values

string

accepts a character string

boolean

accepts “on” or “off”

number

accepts a number

size

accepts a number followed by an optional suffix (K)ilo, (M)ega, (G)iga, (T)era

Since

1.5

CommandLineParameterInfo (Object)

Details about a single parameter of a command line option.

Members

name: string

parameter name

type: CommandLineParameterType

parameter CommandLineParameterType

help: string (optional)

human readable text string, not suitable for parsing.

default: string (optional)

default value string (since 2.1)

Since

1.5

CommandLineOptionInfo (Object)

Details about a command line option, including its list of parameter details

Members

option: string

option name

parameters: array of CommandLineParameterInfo

an array of CommandLineParameterInfo

Since

1.5

query-command-line-options (Command)

Query command line option schema.

Arguments

option: string (optional)

option name

Returns

list of CommandLineOptionInfo for all options (or for the given option).

Errors

• if the given option doesn’t exist

Since

1.5

Example:

-> { "execute": "query-command-line-options",
     "arguments": { "option": "option-rom" } }
<- { "return": [
        {
            "parameters": [
                {
                    "name": "romfile",
                    "type": "string"
                },
                {
                    "name": "bootindex",
                    "type": "number"
                }
            ],
            "option": "option-rom"
        }
     ]
   }

RTC_CHANGE (Event)

Emitted when the guest changes the RTC time.

Arguments

offset: int

offset in seconds between base RTC clock (as specified by -rtc base), and new RTC clock value

qom-path: string

path to the RTC object in the QOM tree

Note

This event is rate-limited. It is not guaranteed that the RTC in the system implements this event, or even that the system has an RTC at all.

Since

0.13

Example:

<- { "event": "RTC_CHANGE",
     "data": { "offset": 78 },
     "timestamp": { "seconds": 1267020223, "microseconds": 435656 } }

VFU_CLIENT_HANGUP (Event)

Emitted when the client of a TYPE_VFIO_USER_SERVER closes the communication channel

Arguments

vfu-id: string

ID of the TYPE_VFIO_USER_SERVER object. It is the last component of vfu-qom-path referenced below

vfu-qom-path: string

path to the TYPE_VFIO_USER_SERVER object in the QOM tree

dev-id: string

ID of attached PCI device

dev-qom-path: string

path to attached PCI device in the QOM tree

Since

7.1

Example:

<- { "event": "VFU_CLIENT_HANGUP",
     "data": { "vfu-id": "vfu1",
               "vfu-qom-path": "/objects/vfu1",
               "dev-id": "sas1",
               "dev-qom-path": "/machine/peripheral/sas1" },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

rtc-reset-reinjection (Command)

This command will reset the RTC interrupt reinjection backlog. Can be used if another mechanism to synchronize guest time is in effect, for example QEMU guest agent’s guest-set-time command.

Since

2.1

Example:

-> { "execute": "rtc-reset-reinjection" }
<- { "return": {} }

If

TARGET_I386

SevState (Enum)

An enumeration of SEV state information used during query-sev.

Values

uninit

The guest is uninitialized.

launch-update

The guest is currently being launched; plaintext data and register state is being imported.

launch-secret

The guest is currently being launched; ciphertext data is being imported.

running

The guest is fully launched or migrated in.

send-update

The guest is currently being migrated out to another machine.

receive-update

The guest is currently being migrated from another machine.

Since

2.12

If

TARGET_I386

SevGuestType (Enum)

An enumeration indicating the type of SEV guest being run.

Values

sev

The guest is a legacy SEV or SEV-ES guest.

sev-snp

The guest is an SEV-SNP guest.

Since

6.2

If

TARGET_I386

SevGuestInfo (Object)

Information specific to legacy SEV/SEV-ES guests.

Members

policy: int

SEV policy value

handle: int

SEV firmware handle

Since

2.12

If

TARGET_I386

SevSnpGuestInfo (Object)

Information specific to SEV-SNP guests.

Members

snp-policy: int

SEV-SNP policy value

Since

9.1

If

TARGET_I386

SevInfo (Object)

Information about Secure Encrypted Virtualization (SEV) support

Members

enabled: boolean

true if SEV is active

api-major: int

SEV API major version

api-minor: int

SEV API minor version

build-id: int

SEV FW build id

state: SevState

SEV guest state

sev-type: SevGuestType

Type of SEV guest being run

The members of SevGuestInfo when sev-type is "sev"

The members of SevSnpGuestInfo when sev-type is "sev-snp"

Since

2.12

If

TARGET_I386

query-sev (Command)

Returns information about SEV

Returns

SevInfo

Since

2.12

Example:

-> { "execute": "query-sev" }
<- { "return": { "enabled": true, "api-major" : 0, "api-minor" : 0,
                 "build-id" : 0, "policy" : 0, "state" : "running",
                 "handle" : 1 } }

If

TARGET_I386

SevLaunchMeasureInfo (Object)

SEV Guest Launch measurement information

Members

data: string

the measurement value encoded in base64

Since

2.12

If

TARGET_I386

query-sev-launch-measure (Command)

Query the SEV guest launch information.

Returns

The SevLaunchMeasureInfo for the guest

Since

2.12

Example:

-> { "execute": "query-sev-launch-measure" }
<- { "return": { "data": "4l8LXeNlSPUDlXPJG5966/8%YZ" } }

If

TARGET_I386

SevCapability (Object)

The struct describes capability for a Secure Encrypted Virtualization feature.

Members

pdh: string

Platform Diffie-Hellman key (base64 encoded)

cert-chain: string

PDH certificate chain (base64 encoded)

cpu0-id: string

Unique ID of CPU0 (base64 encoded) (since 7.1)

cbitpos: int

C-bit location in page table entry

reduced-phys-bits: int

Number of physical Address bit reduction when SEV is enabled

Since

2.12

If

TARGET_I386

query-sev-capabilities (Command)

This command is used to get the SEV capabilities, and is supported on AMD X86 platforms only.

Returns

SevCapability objects.

Since

2.12

Example:

-> { "execute": "query-sev-capabilities" }
<- { "return": { "pdh": "8CCDD8DDD", "cert-chain": "888CCCDDDEE",
                 "cpu0-id": "2lvmGwo+...61iEinw==",
                 "cbitpos": 47, "reduced-phys-bits": 1}}

If

TARGET_I386

sev-inject-launch-secret (Command)

This command injects a secret blob into memory of SEV guest.

Arguments

packet-header: string

the launch secret packet header encoded in base64

secret: string

the launch secret data to be injected encoded in base64

gpa: int (optional)

the guest physical address where secret will be injected.

Since

6.0

If

TARGET_I386

SevAttestationReport (Object)

The struct describes attestation report for a Secure Encrypted Virtualization feature.

Members

data: string

guest attestation report (base64 encoded)

Since

6.1

If

TARGET_I386

query-sev-attestation-report (Command)

This command is used to get the SEV attestation report, and is supported on AMD X86 platforms only.

Arguments

mnonce: string

a random 16 bytes value encoded in base64 (it will be included in report)

Returns

SevAttestationReport objects.

Since

6.1

Example:

-> { "execute" : "query-sev-attestation-report",
                 "arguments": { "mnonce": "aaaaaaa" } }
<- { "return" : { "data": "aaaaaaaabbbddddd"} }

If

TARGET_I386

dump-skeys (Command)

Dump guest’s storage keys

Arguments

filename: string

the path to the file to dump to

Since

2.5

Example:

-> { "execute": "dump-skeys",
     "arguments": { "filename": "/tmp/skeys" } }
<- { "return": {} }

If

TARGET_S390X

GICCapability (Object)

The struct describes capability for a specific GIC (Generic Interrupt Controller) version. These bits are not only decided by QEMU/KVM software version, but also decided by the hardware that the program is running upon.

Members

version: int

version of GIC to be described. Currently, only 2 and 3 are supported.

emulated: boolean

whether current QEMU/hardware supports emulated GIC device in user space.

kernel: boolean

whether current QEMU/hardware supports hardware accelerated GIC device in kernel.

Since

2.6

If

TARGET_ARM

query-gic-capabilities (Command)

This command is ARM-only. It will return a list of GICCapability objects that describe its capability bits.

Returns

a list of GICCapability objects.

Since

2.6

Example:

-> { "execute": "query-gic-capabilities" }
<- { "return": [{ "version": 2, "emulated": true, "kernel": false },
                { "version": 3, "emulated": false, "kernel": true } ] }

If

TARGET_ARM

SGXEPCSection (Object)

Information about intel SGX EPC section info

Members

node: int

the numa node

size: int

the size of EPC section

Since

7.0

SGXInfo (Object)

Information about intel Safe Guard eXtension (SGX) support

Members

sgx: boolean

true if SGX is supported

sgx1: boolean

true if SGX1 is supported

sgx2: boolean

true if SGX2 is supported

flc: boolean

true if FLC is supported

sections: array of SGXEPCSection

The EPC sections info for guest (Since: 7.0)

Since

6.2

If

TARGET_I386

query-sgx (Command)

Returns information about SGX

Returns

SGXInfo

Since

6.2

Example:

-> { "execute": "query-sgx" }
<- { "return": { "sgx": true, "sgx1" : true, "sgx2" : true,
                 "flc": true,
                 "sections": [{"node": 0, "size": 67108864},
                 {"node": 1, "size": 29360128}]} }

If

TARGET_I386

query-sgx-capabilities (Command)

Returns information from host SGX capabilities

Returns

SGXInfo

Since

6.2

Example:

-> { "execute": "query-sgx-capabilities" }
<- { "return": { "sgx": true, "sgx1" : true, "sgx2" : true,
                 "flc": true,
                 "section" : [{"node": 0, "size": 67108864},
                 {"node": 1, "size": 29360128}]} }

If

TARGET_I386

EvtchnPortType (Enum)

An enumeration of Xen event channel port types.

Values

closed

The port is unused.

unbound

The port is allocated and ready to be bound.

interdomain

The port is connected as an interdomain interrupt.

pirq

The port is bound to a physical IRQ (PIRQ).

virq

The port is bound to a virtual IRQ (VIRQ).

ipi

The post is an inter-processor interrupt (IPI).

Since

8.0

If

TARGET_I386

EvtchnInfo (Object)

Information about a Xen event channel port

Members

port: int

the port number

vcpu: int

target vCPU for this port

type: EvtchnPortType

the port type

remote-domain: string

remote domain for interdomain ports

target: int

remote port ID, or virq/pirq number

pending: boolean

port is currently active pending delivery

masked: boolean

port is masked

Since

8.0

If

TARGET_I386

xen-event-list (Command)

Query the Xen event channels opened by the guest.

Returns

list of open event channel ports.

Since

8.0

Example:

-> { "execute": "xen-event-list" }
<- { "return": [
        {
            "pending": false,
            "port": 1,
            "vcpu": 1,
            "remote-domain": "qemu",
            "masked": false,
            "type": "interdomain",
            "target": 1
        },
        {
            "pending": false,
            "port": 2,
            "vcpu": 0,
            "remote-domain": "",
            "masked": false,
            "type": "virq",
            "target": 0
        }
     ]
   }

If

TARGET_I386

xen-event-inject (Command)

Inject a Xen event channel port (interrupt) to the guest.

Arguments

port: int

The port number

Since

8.0

Example:

-> { "execute": "xen-event-inject", "arguments": { "port": 1 } }
<- { "return": { } }

If

TARGET_I386

Audio

AudiodevPerDirectionOptions (Object)

General audio backend options that are used for both playback and recording.

Members

mixing-engine: boolean (optional)

use QEMU’s mixing engine to mix all streams inside QEMU and convert audio formats when not supported by the backend. When set to off, fixed-settings must be also off (default on, since 4.2)

fixed-settings: boolean (optional)

use fixed settings for host input/output. When off, frequency, channels and format must not be specified (default true)

frequency: int (optional)

frequency to use when using fixed settings (default 44100)

channels: int (optional)

number of channels when using fixed settings (default 2)

voices: int (optional)

number of voices to use (default 1)

format: AudioFormat (optional)

sample format to use when using fixed settings (default s16)

buffer-length: int (optional)

the buffer length in microseconds

Since

4.0

AudiodevGenericOptions (Object)

Generic driver-specific options.

Members

in: AudiodevPerDirectionOptions (optional)

options of the capture stream

out: AudiodevPerDirectionOptions (optional)

options of the playback stream

Since

4.0

AudiodevAlsaPerDirectionOptions (Object)

Options of the ALSA backend that are used for both playback and recording.

Members

dev: string (optional)

the name of the ALSA device to use (default ‘default’)

period-length: int (optional)

the period length in microseconds

try-poll: boolean (optional)

attempt to use poll mode, falling back to non-polling access on failure (default true)

The members of AudiodevPerDirectionOptions

Since

4.0

AudiodevAlsaOptions (Object)

Options of the ALSA audio backend.

Members

in: AudiodevAlsaPerDirectionOptions (optional)

options of the capture stream

out: AudiodevAlsaPerDirectionOptions (optional)

options of the playback stream

threshold: int (optional)

set the threshold (in microseconds) when playback starts

Since

4.0

AudiodevSndioOptions (Object)

Options of the sndio audio backend.

Members

in: AudiodevPerDirectionOptions (optional)

options of the capture stream

out: AudiodevPerDirectionOptions (optional)

options of the playback stream

dev: string (optional)

the name of the sndio device to use (default ‘default’)

latency: int (optional)

play buffer size (in microseconds)

Since

7.2

AudiodevCoreaudioPerDirectionOptions (Object)

Options of the Core Audio backend that are used for both playback and recording.

Members

buffer-count: int (optional)

number of buffers

The members of AudiodevPerDirectionOptions

Since

4.0

AudiodevCoreaudioOptions (Object)

Options of the coreaudio audio backend.

Members

in: AudiodevCoreaudioPerDirectionOptions (optional)

options of the capture stream

out: AudiodevCoreaudioPerDirectionOptions (optional)

options of the playback stream

Since

4.0

AudiodevDsoundOptions (Object)

Options of the DirectSound audio backend.

Members

in: AudiodevPerDirectionOptions (optional)

options of the capture stream

out: AudiodevPerDirectionOptions (optional)

options of the playback stream

latency: int (optional)

add extra latency to playback in microseconds (default 10000)

Since

4.0

AudiodevJackPerDirectionOptions (Object)

Options of the JACK backend that are used for both playback and recording.

Members

server-name: string (optional)

select from among several possible concurrent server instances (default: environment variable $JACK_DEFAULT_SERVER if set, else “default”)

client-name: string (optional)

the client name to use. The server will modify this name to create a unique variant, if needed unless exact-name is true (default: the guest’s name)

connect-ports: string (optional)

if set, a regular expression of JACK client port name(s) to monitor for and automatically connect to

start-server: boolean (optional)

start a jack server process if one is not already present (default: false)

exact-name: boolean (optional)

use the exact name requested otherwise JACK automatically generates a unique one, if needed (default: false)

The members of AudiodevPerDirectionOptions

Since

5.1

AudiodevJackOptions (Object)

Options of the JACK audio backend.

Members

in: AudiodevJackPerDirectionOptions (optional)

options of the capture stream

out: AudiodevJackPerDirectionOptions (optional)

options of the playback stream

Since

5.1

AudiodevOssPerDirectionOptions (Object)

Options of the OSS backend that are used for both playback and recording.

Members

dev: string (optional)

file name of the OSS device (default ‘/dev/dsp’)

buffer-count: int (optional)

number of buffers

try-poll: boolean (optional)

attempt to use poll mode, falling back to non-polling access on failure (default true)

The members of AudiodevPerDirectionOptions

Since

4.0

AudiodevOssOptions (Object)

Options of the OSS audio backend.

Members

in: AudiodevOssPerDirectionOptions (optional)

options of the capture stream

out: AudiodevOssPerDirectionOptions (optional)

options of the playback stream

try-mmap: boolean (optional)

try using memory-mapped access, falling back to non-memory-mapped access on failure (default true)

exclusive: boolean (optional)

open device in exclusive mode (vmix won’t work) (default false)

dsp-policy: int (optional)

set the timing policy of the device (between 0 and 10, where smaller number means smaller latency but higher CPU usage) or -1 to use fragment mode (option ignored on some platforms) (default 5)

Since

4.0

AudiodevPaPerDirectionOptions (Object)

Options of the Pulseaudio backend that are used for both playback and recording.

Members

name: string (optional)

name of the sink/source to use

stream-name: string (optional)

name of the PulseAudio stream created by qemu. Can be used to identify the stream in PulseAudio when you create multiple PulseAudio devices or run multiple qemu instances (default: audiodev’s id, since 4.2)

latency: int (optional)

latency you want PulseAudio to achieve in microseconds (default 15000)

The members of AudiodevPerDirectionOptions

Since

4.0

AudiodevPaOptions (Object)

Options of the PulseAudio audio backend.

Members

in: AudiodevPaPerDirectionOptions (optional)

options of the capture stream

out: AudiodevPaPerDirectionOptions (optional)

options of the playback stream

server: string (optional)

PulseAudio server address (default: let PulseAudio choose)

Since

4.0

AudiodevPipewirePerDirectionOptions (Object)

Options of the PipeWire backend that are used for both playback and recording.

Members

name: string (optional)

name of the sink/source to use

stream-name: string (optional)

name of the PipeWire stream created by qemu. Can be used to identify the stream in PipeWire when you create multiple PipeWire devices or run multiple qemu instances (default: audiodev’s id)

latency: int (optional)

latency you want PipeWire to achieve in microseconds (default 46000)

The members of AudiodevPerDirectionOptions

Since

8.1

AudiodevPipewireOptions (Object)

Options of the PipeWire audio backend.

Members

in: AudiodevPipewirePerDirectionOptions (optional)

options of the capture stream

out: AudiodevPipewirePerDirectionOptions (optional)

options of the playback stream

Since

8.1

AudiodevSdlPerDirectionOptions (Object)

Options of the SDL audio backend that are used for both playback and recording.

Members

buffer-count: int (optional)

number of buffers (default 4)

The members of AudiodevPerDirectionOptions

Since

6.0

AudiodevSdlOptions (Object)

Options of the SDL audio backend.

Members

in: AudiodevSdlPerDirectionOptions (optional)

options of the recording stream

out: AudiodevSdlPerDirectionOptions (optional)

options of the playback stream

Since

6.0

AudiodevWavOptions (Object)

Options of the wav audio backend.

Members

in: AudiodevPerDirectionOptions (optional)

options of the capture stream

out: AudiodevPerDirectionOptions (optional)

options of the playback stream

path: string (optional)

name of the wav file to record (default ‘qemu.wav’)

Since

4.0

AudioFormat (Enum)

An enumeration of possible audio formats.

Values

u8

unsigned 8 bit integer

s8

signed 8 bit integer

u16

unsigned 16 bit integer

s16

signed 16 bit integer

u32

unsigned 32 bit integer

s32

signed 32 bit integer

f32

single precision floating-point (since 5.0)

Since

4.0

AudiodevDriver (Enum)

An enumeration of possible audio backend drivers.

Values

jack (If: CONFIG_AUDIO_JACK)

JACK audio backend (since 5.1)

none

Not documented

alsa (If: CONFIG_AUDIO_ALSA)

Not documented

coreaudio (If: CONFIG_AUDIO_COREAUDIO)

Not documented

dbus (If: CONFIG_DBUS_DISPLAY)

Not documented

dsound (If: CONFIG_AUDIO_DSOUND)

Not documented

oss (If: CONFIG_AUDIO_OSS)

Not documented

pa (If: CONFIG_AUDIO_PA)

Not documented

pipewire (If: CONFIG_AUDIO_PIPEWIRE)

Not documented

sdl (If: CONFIG_AUDIO_SDL)

Not documented

sndio (If: CONFIG_AUDIO_SNDIO)

Not documented

spice (If: CONFIG_SPICE)

Not documented

wav

Not documented

Since

4.0

Audiodev (Object)

Options of an audio backend.

Members

id: string

identifier of the backend

driver: AudiodevDriver

the backend driver to use

timer-period: int (optional)

timer period (in microseconds, 0: use lowest possible)

The members of AudiodevGenericOptions when driver is "none"

The members of AudiodevAlsaOptions when driver is "alsa" (If: CONFIG_AUDIO_ALSA)

The members of AudiodevCoreaudioOptions when driver is "coreaudio" (If: CONFIG_AUDIO_COREAUDIO)

The members of AudiodevGenericOptions when driver is "dbus" (If: CONFIG_DBUS_DISPLAY)

The members of AudiodevDsoundOptions when driver is "dsound" (If: CONFIG_AUDIO_DSOUND)

The members of AudiodevJackOptions when driver is "jack" (If: CONFIG_AUDIO_JACK)

The members of AudiodevOssOptions when driver is "oss" (If: CONFIG_AUDIO_OSS)

The members of AudiodevPaOptions when driver is "pa" (If: CONFIG_AUDIO_PA)

The members of AudiodevPipewireOptions when driver is "pipewire" (If: CONFIG_AUDIO_PIPEWIRE)

The members of AudiodevSdlOptions when driver is "sdl" (If: CONFIG_AUDIO_SDL)

The members of AudiodevSndioOptions when driver is "sndio" (If: CONFIG_AUDIO_SNDIO)

The members of AudiodevGenericOptions when driver is "spice" (If: CONFIG_SPICE)

The members of AudiodevWavOptions when driver is "wav"

Since

4.0

query-audiodevs (Command)

Returns information about audiodev configuration

Returns

array of Audiodev

Since

8.0

ACPI

AcpiTableOptions (Object)

Specify an ACPI table on the command line to load.

At most one of file and data can be specified. The list of files specified by any one of them is loaded and concatenated in order. If both are omitted, data is implied.

Other fields / optargs can be used to override fields of the generic ACPI table header; refer to the ACPI specification 5.0, section 5.2.6 System Description Table Header. If a header field is not overridden, then the corresponding value from the concatenated blob is used (in case of file), or it is filled in with a hard-coded value (in case of data).

String fields are copied into the matching ACPI member from lowest address upwards, and silently truncated / NUL-padded to length.

Members

sig: string (optional)

table signature / identifier (4 bytes)

rev: int (optional)

table revision number (dependent on signature, 1 byte)

oem_id: string (optional)

OEM identifier (6 bytes)

oem_table_id: string (optional)

OEM table identifier (8 bytes)

oem_rev: int (optional)

OEM-supplied revision number (4 bytes)

asl_compiler_id: string (optional)

identifier of the utility that created the table (4 bytes)

asl_compiler_rev: int (optional)

revision number of the utility that created the table (4 bytes)

file: string (optional)

colon (:) separated list of pathnames to load and concatenate as table data. The resultant binary blob is expected to have an ACPI table header. At least one file is required. This field excludes data.

data: string (optional)

colon (:) separated list of pathnames to load and concatenate as table data. The resultant binary blob must not have an ACPI table header. At least one file is required. This field excludes file.

Since

1.5

ACPISlotType (Enum)

Values

DIMM

memory slot

CPU

logical CPU slot (since 2.7)

ACPIOSTInfo (Object)

OSPM Status Indication for a device For description of possible values of source and status fields see “_OST (OSPM Status Indication)” chapter of ACPI5.0 spec.

Members

device: string (optional)

device ID associated with slot

slot: string

slot ID, unique per slot of a given slot-type

slot-type: ACPISlotType

type of the slot

source: int

an integer containing the source event

status: int

an integer containing the status code

Since

2.1

query-acpi-ospm-status (Command)

Return a list of ACPIOSTInfo for devices that support status reporting via ACPI _OST method.

Since

2.1

Example:

-> { "execute": "query-acpi-ospm-status" }
<- { "return": [ { "device": "d1", "slot": "0", "slot-type": "DIMM", "source": 1, "status": 0},
                 { "slot": "1", "slot-type": "DIMM", "source": 0, "status": 0},
                 { "slot": "2", "slot-type": "DIMM", "source": 0, "status": 0},
                 { "slot": "3", "slot-type": "DIMM", "source": 0, "status": 0}
   ]}

ACPI_DEVICE_OST (Event)

Emitted when guest executes ACPI _OST method.

Arguments

info: ACPIOSTInfo

OSPM Status Indication

Since

2.1

Example:

<- { "event": "ACPI_DEVICE_OST",
     "data": { "info": { "device": "d1", "slot": "0",
                         "slot-type": "DIMM", "source": 1, "status": 0 } },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

PCI

PciMemoryRange (Object)

A PCI device memory region

Members

base: int

the starting address (guest physical)

limit: int

the ending address (guest physical)

Since

0.14

PciMemoryRegion (Object)

Information about a PCI device I/O region.

Members

bar: int

the index of the Base Address Register for this region

type: string

• ‘io’ if the region is a PIO region

• ‘memory’ if the region is a MMIO region

address: int

memory address

size: int

memory size

prefetch: boolean (optional)

if type is ‘memory’, true if the memory is prefetchable

mem_type_64: boolean (optional)

if type is ‘memory’, true if the BAR is 64-bit

Since

0.14

PciBusInfo (Object)

Information about a bus of a PCI Bridge device

Members

number: int

primary bus interface number. This should be the number of the bus the device resides on.

secondary: int

secondary bus interface number. This is the number of the main bus for the bridge

subordinate: int

This is the highest number bus that resides below the bridge.

io_range: PciMemoryRange

The PIO range for all devices on this bridge

memory_range: PciMemoryRange

The MMIO range for all devices on this bridge

prefetchable_range: PciMemoryRange

The range of prefetchable MMIO for all devices on this bridge

Since

2.4

PciBridgeInfo (Object)

Information about a PCI Bridge device

Members

bus: PciBusInfo

information about the bus the device resides on

devices: array of PciDeviceInfo (optional)

a list of PciDeviceInfo for each device on this bridge

Since

0.14

PciDeviceClass (Object)

Information about the Class of a PCI device

Members

desc: string (optional)

a string description of the device’s class (not stable, and should only be treated as informational)

class: int

the class code of the device

Since

2.4

PciDeviceId (Object)

Information about the Id of a PCI device

Members

device: int

the PCI device id

vendor: int

the PCI vendor id

subsystem: int (optional)

the PCI subsystem id (since 3.1)

subsystem-vendor: int (optional)

the PCI subsystem vendor id (since 3.1)

Since

2.4

PciDeviceInfo (Object)

Information about a PCI device

Members

bus: int

the bus number of the device

slot: int

the slot the device is located in

function: int

the function of the slot used by the device

class_info: PciDeviceClass

the class of the device

id: PciDeviceId

the PCI device id

irq: int (optional)

if an IRQ is assigned to the device, the IRQ number

irq_pin: int

the IRQ pin, zero means no IRQ (since 5.1)

qdev_id: string

the device name of the PCI device

pci_bridge: PciBridgeInfo (optional)

if the device is a PCI bridge, the bridge information

regions: array of PciMemoryRegion

a list of the PCI I/O regions associated with the device

Since

0.14

PciInfo (Object)

Information about a PCI bus

Members

bus: int

the bus index

devices: array of PciDeviceInfo

a list of devices on this bus

Since

0.14

query-pci (Command)

Return information about the PCI bus topology of the guest.

Returns

a list of PciInfo for each PCI bus. Each bus is represented by a json-object, which has a key with a json-array of all PCI devices attached to it. Each device is represented by a json-object.

Since

0.14

Example:

-> { "execute": "query-pci" }
<- { "return": [
         {
            "bus": 0,
            "devices": [
               {
                  "bus": 0,
                  "qdev_id": "",
                  "slot": 0,
                  "class_info": {
                     "class": 1536,
                     "desc": "Host bridge"
                  },
                  "id": {
                     "device": 32902,
                     "vendor": 4663
                  },
                  "function": 0,
                  "regions": [
                  ]
               },
               {
                  "bus": 0,
                  "qdev_id": "",
                  "slot": 1,
                  "class_info": {
                     "class": 1537,
                     "desc": "ISA bridge"
                  },
                  "id": {
                     "device": 32902,
                     "vendor": 28672
                  },
                  "function": 0,
                  "regions": [
                  ]
               },
               {
                  "bus": 0,
                  "qdev_id": "",
                  "slot": 1,
                  "class_info": {
                     "class": 257,
                     "desc": "IDE controller"
                  },
                  "id": {
                     "device": 32902,
                     "vendor": 28688
                  },
                  "function": 1,
                  "regions": [
                     {
                        "bar": 4,
                        "size": 16,
                        "address": 49152,
                        "type": "io"
                     }
                  ]
               },
               {
                  "bus": 0,
                  "qdev_id": "",
                  "slot": 2,
                  "class_info": {
                     "class": 768,
                     "desc": "VGA controller"
                  },
                  "id": {
                     "device": 4115,
                     "vendor": 184
                  },
                  "function": 0,
                  "regions": [
                     {
                        "prefetch": true,
                        "mem_type_64": false,
                        "bar": 0,
                        "size": 33554432,
                        "address": 4026531840,
                        "type": "memory"
                     },
                     {
                        "prefetch": false,
                        "mem_type_64": false,
                        "bar": 1,
                        "size": 4096,
                        "address": 4060086272,
                        "type": "memory"
                     },
                     {
                        "prefetch": false,
                        "mem_type_64": false,
                        "bar": 6,
                        "size": 65536,
                        "address": -1,
                        "type": "memory"
                     }
                  ]
               },
               {
                  "bus": 0,
                  "qdev_id": "",
                  "irq": 11,
                  "slot": 4,
                  "class_info": {
                     "class": 1280,
                     "desc": "RAM controller"
                  },
                  "id": {
                     "device": 6900,
                     "vendor": 4098
                  },
                  "function": 0,
                  "regions": [
                     {
                        "bar": 0,
                        "size": 32,
                        "address": 49280,
                        "type": "io"
                     }
                  ]
               }
            ]
         }
      ]
   }

This example has been shortened as the real response is too long.

Statistics

StatsType (Enum)

Enumeration of statistics types

Values

cumulative

stat is cumulative; value can only increase.

instant

stat is instantaneous; value can increase or decrease.

peak

stat is the peak value; value can only increase.

linear-histogram

stat is a linear histogram.

log2-histogram

stat is a logarithmic histogram, with one bucket for each power of two.

Since

7.1

StatsUnit (Enum)

Enumeration of unit of measurement for statistics

Values

bytes

stat reported in bytes.

seconds

stat reported in seconds.

cycles

stat reported in clock cycles.

boolean

stat is a boolean value.

Since

7.1

StatsProvider (Enum)

Enumeration of statistics providers.

Values

kvm

since 7.1

cryptodev

since 8.0

Since

7.1

StatsTarget (Enum)

The kinds of objects on which one can request statistics.

Values

vm

statistics that apply to the entire virtual machine or the entire QEMU process.

vcpu

statistics that apply to a single virtual CPU.

cryptodev

statistics that apply to a crypto device (since 8.0)

Since

7.1

StatsRequest (Object)

Indicates a set of statistics that should be returned by query-stats.

Members

provider: StatsProvider

provider for which to return statistics.

names: array of string (optional)

statistics to be returned (all if omitted).

Since

7.1

StatsVCPUFilter (Object)

Members

vcpus: array of string (optional)

list of QOM paths for the desired vCPU objects.

Since

7.1

StatsFilter (Object)

The arguments to the query-stats command; specifies a target for which to request statistics and optionally the required subset of information for that target.

Members

target: StatsTarget

the kind of objects to query. Note that each possible target may enable additional filtering options

providers: array of StatsRequest (optional)

which providers to request statistics from, and optionally which named values to return within each provider

The members of StatsVCPUFilter when target is "vcpu"

Since

7.1

StatsValue (Alternate)

Members

scalar: int

single unsigned 64-bit integers.

boolean: boolean

single boolean value.

list: array of int

list of unsigned 64-bit integers (used for histograms).

Since

7.1

Stats (Object)

Members

name: string

name of stat.

value: StatsValue

stat value.

Since

7.1

StatsResult (Object)

Members

provider: StatsProvider

provider for this set of statistics.

qom-path: string (optional)

Path to the object for which the statistics are returned, if the object is exposed in the QOM tree

stats: array of Stats

list of statistics.

Since

7.1

query-stats (Command)

Return runtime-collected statistics for objects such as the VM or its vCPUs.

The arguments are a StatsFilter and specify the provider and objects to return statistics about.

Arguments

The members of StatsFilter

Returns

a list of StatsResult, one for each provider and object (e.g., for each vCPU).

Since

7.1

StatsSchemaValue (Object)

Schema for a single statistic.

Members

name: string

name of the statistic; each element of the schema is uniquely identified by a target, a provider (both available in StatsSchema) and the name.

type: StatsType

kind of statistic.

unit: StatsUnit (optional)

basic unit of measure for the statistic; if missing, the statistic is a simple number or counter.

base: int (optional)

base for the multiple of unit in which the statistic is measured. Only present if exponent is non-zero; base and exponent together form a SI prefix (e.g., _nano-_ for base=10 and exponent=-9) or IEC binary prefix (e.g. _kibi-_ for base=2 and exponent=10)

exponent: int

exponent for the multiple of unit in which the statistic is expressed, or 0 for the basic unit

bucket-size: int (optional)

Present when type is “linear-histogram”, contains the width of each bucket of the histogram.

Since

7.1

StatsSchema (Object)

Schema for all available statistics for a provider and target.

Members

provider: StatsProvider

provider for this set of statistics.

target: StatsTarget

the kind of object that can be queried through the provider.

stats: array of StatsSchemaValue

list of statistics.

Since

7.1

query-stats-schemas (Command)

Return the schema for all available runtime-collected statistics.

Arguments

provider: StatsProvider (optional)

a provider to restrict the query to.

Note

Runtime-collected statistics and their names fall outside QEMU’s usual deprecation policies. QEMU will try to keep the set of available data stable, together with their names, but will not guarantee stability at all costs; the same is true of providers that source statistics externally, e.g. from Linux. For example, if the same value is being tracked with different names on different architectures or by different providers, one of them might be renamed. A statistic might go away if an algorithm is changed or some code is removed; changing a default might cause previously useful statistics to always report 0. Such changes, however, are expected to be rare.

Since

7.1

Virtio devices

VirtioInfo (Object)

Basic information about a given VirtIODevice

Members

path: string

The VirtIODevice’s canonical QOM path

name: string

Name of the VirtIODevice

Since

7.2

x-query-virtio (Command)

Returns a list of all realized VirtIODevices

Features

unstable

This command is meant for debugging.

Returns

List of gathered VirtIODevices

Since

7.2

Example:

-> { "execute": "x-query-virtio" }
<- { "return": [
         {
             "name": "virtio-input",
             "path": "/machine/peripheral-anon/device[4]/virtio-backend"
         },
         {
             "name": "virtio-crypto",
             "path": "/machine/peripheral/crypto0/virtio-backend"
         },
         {
             "name": "virtio-scsi",
             "path": "/machine/peripheral-anon/device[2]/virtio-backend"
         },
         {
             "name": "virtio-net",
             "path": "/machine/peripheral-anon/device[1]/virtio-backend"
         },
         {
             "name": "virtio-serial",
             "path": "/machine/peripheral-anon/device[0]/virtio-backend"
         }
     ]
   }

VhostStatus (Object)

Information about a vhost device. This information will only be displayed if the vhost device is active.

Members

n-mem-sections: int

vhost_dev n_mem_sections

n-tmp-sections: int

vhost_dev n_tmp_sections

nvqs: int

vhost_dev nvqs (number of virtqueues being used)

vq-index: int

vhost_dev vq_index

features: VirtioDeviceFeatures

vhost_dev features

acked-features: VirtioDeviceFeatures

vhost_dev acked_features

backend-features: VirtioDeviceFeatures

vhost_dev backend_features

protocol-features: VhostDeviceProtocols

vhost_dev protocol_features

max-queues: int

vhost_dev max_queues

backend-cap: int

vhost_dev backend_cap

log-enabled: boolean

vhost_dev log_enabled flag

log-size: int

vhost_dev log_size

Since

7.2

VirtioStatus (Object)

Full status of the virtio device with most VirtIODevice members. Also includes the full status of the corresponding vhost device if the vhost device is active.

Members

name: string

VirtIODevice name

device-id: int

VirtIODevice ID

vhost-started: boolean

VirtIODevice vhost_started flag

guest-features: VirtioDeviceFeatures

VirtIODevice guest_features

host-features: VirtioDeviceFeatures

VirtIODevice host_features

backend-features: VirtioDeviceFeatures

VirtIODevice backend_features

device-endian: string

VirtIODevice device_endian

num-vqs: int

VirtIODevice virtqueue count. This is the number of active virtqueues being used by the VirtIODevice.

status: VirtioDeviceStatus

VirtIODevice configuration status (VirtioDeviceStatus)

isr: int

VirtIODevice ISR

queue-sel: int

VirtIODevice queue_sel

vm-running: boolean

VirtIODevice vm_running flag

broken: boolean

VirtIODevice broken flag

disabled: boolean

VirtIODevice disabled flag

use-started: boolean

VirtIODevice use_started flag

started: boolean

VirtIODevice started flag

start-on-kick: boolean

VirtIODevice start_on_kick flag

disable-legacy-check: boolean

VirtIODevice disabled_legacy_check flag

bus-name: string

VirtIODevice bus_name

use-guest-notifier-mask: boolean

VirtIODevice use_guest_notifier_mask flag

vhost-dev: VhostStatus (optional)

Corresponding vhost device info for a given VirtIODevice. Present if the given VirtIODevice has an active vhost device.

Since

7.2

x-query-virtio-status (Command)

Poll for a comprehensive status of a given virtio device

Arguments

path: string

Canonical QOM path of the VirtIODevice

Features

unstable

This command is meant for debugging.

Returns

VirtioStatus of the virtio device

Since

7.2

Example:

Poll for the status of virtio-crypto (no vhost-crypto active)

-> { "execute": "x-query-virtio-status",
     "arguments": { "path": "/machine/peripheral/crypto0/virtio-backend" }
   }
<- { "return": {
         "device-endian": "little",
         "bus-name": "",
         "disable-legacy-check": false,
         "name": "virtio-crypto",
         "started": true,
         "device-id": 20,
         "backend-features": {
             "transports": [],
             "dev-features": []
         },
         "start-on-kick": false,
         "isr": 1,
         "broken": false,
         "status": {
             "statuses": [
                 "VIRTIO_CONFIG_S_ACKNOWLEDGE: Valid virtio device found",
                 "VIRTIO_CONFIG_S_DRIVER: Guest OS compatible with device",
                 "VIRTIO_CONFIG_S_FEATURES_OK: Feature negotiation complete",
                 "VIRTIO_CONFIG_S_DRIVER_OK: Driver setup and ready"
             ]
         },
         "num-vqs": 2,
         "guest-features": {
             "dev-features": [],
             "transports": [
                 "VIRTIO_RING_F_EVENT_IDX: Used & avail. event fields enabled",
                 "VIRTIO_RING_F_INDIRECT_DESC: Indirect descriptors supported",
                 "VIRTIO_F_VERSION_1: Device compliant for v1 spec (legacy)"
             ]
         },
         "host-features": {
             "unknown-dev-features": 1073741824,
             "dev-features": [],
             "transports": [
                 "VIRTIO_RING_F_EVENT_IDX: Used & avail. event fields enabled",
                 "VIRTIO_RING_F_INDIRECT_DESC: Indirect descriptors supported",
                 "VIRTIO_F_VERSION_1: Device compliant for v1 spec (legacy)",
                 "VIRTIO_F_ANY_LAYOUT: Device accepts arbitrary desc. layouts",
                 "VIRTIO_F_NOTIFY_ON_EMPTY: Notify when device runs out of avail. descs. on VQ"
             ]
         },
         "use-guest-notifier-mask": true,
         "vm-running": true,
         "queue-sel": 1,
         "disabled": false,
         "vhost-started": false,
         "use-started": true
     }
   }

Example:

Poll for the status of virtio-net (vhost-net is active)

-> { "execute": "x-query-virtio-status",
     "arguments": { "path": "/machine/peripheral-anon/device[1]/virtio-backend" }
   }
<- { "return": {
         "device-endian": "little",
         "bus-name": "",
         "disabled-legacy-check": false,
         "name": "virtio-net",
         "started": true,
         "device-id": 1,
         "vhost-dev": {
             "n-tmp-sections": 4,
             "n-mem-sections": 4,
             "max-queues": 1,
             "backend-cap": 2,
             "log-size": 0,
             "backend-features": {
                 "dev-features": [],
                 "transports": []
             },
             "nvqs": 2,
             "protocol-features": {
                 "protocols": []
             },
             "vq-index": 0,
             "log-enabled": false,
             "acked-features": {
                 "dev-features": [
                     "VIRTIO_NET_F_MRG_RXBUF: Driver can merge receive buffers"
                 ],
                 "transports": [
                     "VIRTIO_RING_F_EVENT_IDX: Used & avail. event fields enabled",
                     "VIRTIO_RING_F_INDIRECT_DESC: Indirect descriptors supported",
                     "VIRTIO_F_VERSION_1: Device compliant for v1 spec (legacy)"
                 ]
             },
             "features": {
                 "dev-features": [
                     "VHOST_F_LOG_ALL: Logging write descriptors supported",
                     "VIRTIO_NET_F_MRG_RXBUF: Driver can merge receive buffers"
                 ],
                 "transports": [
                     "VIRTIO_RING_F_EVENT_IDX: Used & avail. event fields enabled",
                     "VIRTIO_RING_F_INDIRECT_DESC: Indirect descriptors supported",
                     "VIRTIO_F_IOMMU_PLATFORM: Device can be used on IOMMU platform",
                     "VIRTIO_F_VERSION_1: Device compliant for v1 spec (legacy)",
                     "VIRTIO_F_ANY_LAYOUT: Device accepts arbitrary desc. layouts",
                     "VIRTIO_F_NOTIFY_ON_EMPTY: Notify when device runs out of avail. descs. on VQ"
                 ]
             }
         },
         "backend-features": {
             "dev-features": [
                 "VHOST_USER_F_PROTOCOL_FEATURES: Vhost-user protocol features negotiation supported",
                 "VIRTIO_NET_F_GSO: Handling GSO-type packets supported",
                 "VIRTIO_NET_F_CTRL_MAC_ADDR: MAC address set through control channel",
                 "VIRTIO_NET_F_GUEST_ANNOUNCE: Driver sending gratuitous packets supported",
                 "VIRTIO_NET_F_CTRL_RX_EXTRA: Extra RX mode control supported",
                 "VIRTIO_NET_F_CTRL_VLAN: Control channel VLAN filtering supported",
                 "VIRTIO_NET_F_CTRL_RX: Control channel RX mode supported",
                 "VIRTIO_NET_F_CTRL_VQ: Control channel available",
                 "VIRTIO_NET_F_STATUS: Configuration status field available",
                 "VIRTIO_NET_F_MRG_RXBUF: Driver can merge receive buffers",
                 "VIRTIO_NET_F_HOST_UFO: Device can receive UFO",
                 "VIRTIO_NET_F_HOST_ECN: Device can receive TSO with ECN",
                 "VIRTIO_NET_F_HOST_TSO6: Device can receive TSOv6",
                 "VIRTIO_NET_F_HOST_TSO4: Device can receive TSOv4",
                 "VIRTIO_NET_F_GUEST_UFO: Driver can receive UFO",
                 "VIRTIO_NET_F_GUEST_ECN: Driver can receive TSO with ECN",
                 "VIRTIO_NET_F_GUEST_TSO6: Driver can receive TSOv6",
                 "VIRTIO_NET_F_GUEST_TSO4: Driver can receive TSOv4",
                 "VIRTIO_NET_F_MAC: Device has given MAC address",
                 "VIRTIO_NET_F_CTRL_GUEST_OFFLOADS: Control channel offloading reconfig. supported",
                 "VIRTIO_NET_F_GUEST_CSUM: Driver handling packets with partial checksum supported",
                 "VIRTIO_NET_F_CSUM: Device handling packets with partial checksum supported"
             ],
             "transports": [
                 "VIRTIO_RING_F_EVENT_IDX: Used & avail. event fields enabled",
                 "VIRTIO_RING_F_INDIRECT_DESC: Indirect descriptors supported",
                 "VIRTIO_F_VERSION_1: Device compliant for v1 spec (legacy)",
                 "VIRTIO_F_ANY_LAYOUT: Device accepts arbitrary desc. layouts",
                 "VIRTIO_F_NOTIFY_ON_EMPTY: Notify when device runs out of avail. descs. on VQ"
             ]
         },
         "start-on-kick": false,
         "isr": 1,
         "broken": false,
         "status": {
             "statuses": [
                 "VIRTIO_CONFIG_S_ACKNOWLEDGE: Valid virtio device found",
                 "VIRTIO_CONFIG_S_DRIVER: Guest OS compatible with device",
                 "VIRTIO_CONFIG_S_FEATURES_OK: Feature negotiation complete",
                 "VIRTIO_CONFIG_S_DRIVER_OK: Driver setup and ready"
             ]
         },
         "num-vqs": 3,
         "guest-features": {
             "dev-features": [
                 "VIRTIO_NET_F_CTRL_MAC_ADDR: MAC address set through control channel",
                 "VIRTIO_NET_F_GUEST_ANNOUNCE: Driver sending gratuitous packets supported",
                 "VIRTIO_NET_F_CTRL_VLAN: Control channel VLAN filtering supported",
                 "VIRTIO_NET_F_CTRL_RX: Control channel RX mode supported",
                 "VIRTIO_NET_F_CTRL_VQ: Control channel available",
                 "VIRTIO_NET_F_STATUS: Configuration status field available",
                 "VIRTIO_NET_F_MRG_RXBUF: Driver can merge receive buffers",
                 "VIRTIO_NET_F_HOST_UFO: Device can receive UFO",
                 "VIRTIO_NET_F_HOST_ECN: Device can receive TSO with ECN",
                 "VIRTIO_NET_F_HOST_TSO6: Device can receive TSOv6",
                 "VIRTIO_NET_F_HOST_TSO4: Device can receive TSOv4",
                 "VIRTIO_NET_F_GUEST_UFO: Driver can receive UFO",
                 "VIRTIO_NET_F_GUEST_ECN: Driver can receive TSO with ECN",
                 "VIRTIO_NET_F_GUEST_TSO6: Driver can receive TSOv6",
                 "VIRTIO_NET_F_GUEST_TSO4: Driver can receive TSOv4",
                 "VIRTIO_NET_F_MAC: Device has given MAC address",
                 "VIRTIO_NET_F_CTRL_GUEST_OFFLOADS: Control channel offloading reconfig. supported",
                 "VIRTIO_NET_F_GUEST_CSUM: Driver handling packets with partial checksum supported",
                 "VIRTIO_NET_F_CSUM: Device handling packets with partial checksum supported"
             ],
             "transports": [
                 "VIRTIO_RING_F_EVENT_IDX: Used & avail. event fields enabled",
                 "VIRTIO_RING_F_INDIRECT_DESC: Indirect descriptors supported",
                 "VIRTIO_F_VERSION_1: Device compliant for v1 spec (legacy)"
            ]
         },
         "host-features": {
             "dev-features": [
                 "VHOST_USER_F_PROTOCOL_FEATURES: Vhost-user protocol features negotiation supported",
                 "VIRTIO_NET_F_GSO: Handling GSO-type packets supported",
                 "VIRTIO_NET_F_CTRL_MAC_ADDR: MAC address set through control channel",
                 "VIRTIO_NET_F_GUEST_ANNOUNCE: Driver sending gratuitous packets supported",
                 "VIRTIO_NET_F_CTRL_RX_EXTRA: Extra RX mode control supported",
                 "VIRTIO_NET_F_CTRL_VLAN: Control channel VLAN filtering supported",
                 "VIRTIO_NET_F_CTRL_RX: Control channel RX mode supported",
                 "VIRTIO_NET_F_CTRL_VQ: Control channel available",
                 "VIRTIO_NET_F_STATUS: Configuration status field available",
                 "VIRTIO_NET_F_MRG_RXBUF: Driver can merge receive buffers",
                 "VIRTIO_NET_F_HOST_UFO: Device can receive UFO",
                 "VIRTIO_NET_F_HOST_ECN: Device can receive TSO with ECN",
                 "VIRTIO_NET_F_HOST_TSO6: Device can receive TSOv6",
                 "VIRTIO_NET_F_HOST_TSO4: Device can receive TSOv4",
                 "VIRTIO_NET_F_GUEST_UFO: Driver can receive UFO",
                 "VIRTIO_NET_F_GUEST_ECN: Driver can receive TSO with ECN",
                 "VIRTIO_NET_F_GUEST_TSO6: Driver can receive TSOv6",
                 "VIRTIO_NET_F_GUEST_TSO4: Driver can receive TSOv4",
                 "VIRTIO_NET_F_MAC: Device has given MAC address",
                 "VIRTIO_NET_F_CTRL_GUEST_OFFLOADS: Control channel offloading reconfig. supported",
                 "VIRTIO_NET_F_GUEST_CSUM: Driver handling packets with partial checksum supported",
                 "VIRTIO_NET_F_CSUM: Device handling packets with partial checksum supported"
             ],
             "transports": [
                 "VIRTIO_RING_F_EVENT_IDX: Used & avail. event fields enabled",
                 "VIRTIO_RING_F_INDIRECT_DESC: Indirect descriptors supported",
                 "VIRTIO_F_VERSION_1: Device compliant for v1 spec (legacy)",
                 "VIRTIO_F_ANY_LAYOUT: Device accepts arbitrary desc. layouts",
                 "VIRTIO_F_NOTIFY_ON_EMPTY: Notify when device runs out of avail. descs. on VQ"
            ]
         },
         "use-guest-notifier-mask": true,
         "vm-running": true,
         "queue-sel": 2,
         "disabled": false,
         "vhost-started": true,
         "use-started": true
     }
   }

VirtioDeviceStatus (Object)

A structure defined to list the configuration statuses of a virtio device

Members

statuses: array of string

List of decoded configuration statuses of the virtio device

unknown-statuses: int (optional)

Virtio device statuses bitmap that have not been decoded

Since

7.2

VhostDeviceProtocols (Object)

A structure defined to list the vhost user protocol features of a Vhost User device

Members

protocols: array of string

List of decoded vhost user protocol features of a vhost user device

unknown-protocols: int (optional)

Vhost user device protocol features bitmap that have not been decoded

Since

7.2

VirtioDeviceFeatures (Object)

The common fields that apply to most Virtio devices. Some devices may not have their own device-specific features (e.g. virtio-rng).

Members

transports: array of string

List of transport features of the virtio device

dev-features: array of string (optional)

List of device-specific features (if the device has unique features)

unknown-dev-features: int (optional)

Virtio device features bitmap that have not been decoded

Since

7.2

VirtQueueStatus (Object)

Information of a VirtIODevice VirtQueue, including most members of the VirtQueue data structure.

Members

name: string

Name of the VirtIODevice that uses this VirtQueue

queue-index: int

VirtQueue queue_index

inuse: int

VirtQueue inuse

vring-num: int

VirtQueue vring.num

vring-num-default: int

VirtQueue vring.num_default

vring-align: int

VirtQueue vring.align

vring-desc: int

VirtQueue vring.desc (descriptor area)

vring-avail: int

VirtQueue vring.avail (driver area)

vring-used: int

VirtQueue vring.used (device area)

last-avail-idx: int (optional)

VirtQueue last_avail_idx or return of vhost_dev vhost_get_vring_base (if vhost active)

shadow-avail-idx: int (optional)

VirtQueue shadow_avail_idx

used-idx: int

VirtQueue used_idx

signalled-used: int

VirtQueue signalled_used

signalled-used-valid: boolean

VirtQueue signalled_used_valid flag

Since

7.2

x-query-virtio-queue-status (Command)

Return the status of a given VirtIODevice’s VirtQueue

Arguments

path: string

VirtIODevice canonical QOM path

queue: int

VirtQueue index to examine

Features

unstable

This command is meant for debugging.

Returns

VirtQueueStatus of the VirtQueue

Note

last_avail_idx will not be displayed in the case where the selected VirtIODevice has a running vhost device and the VirtIODevice VirtQueue index (queue) does not exist for the corresponding vhost device vhost_virtqueue. Also, shadow_avail_idx will not be displayed in the case where the selected VirtIODevice has a running vhost device.

Since

7.2

Example:

Get VirtQueueStatus for virtio-vsock (vhost-vsock running)

-> { "execute": "x-query-virtio-queue-status",
     "arguments": { "path": "/machine/peripheral/vsock0/virtio-backend",
                    "queue": 1 }
   }
<- { "return": {
         "signalled-used": 0,
         "inuse": 0,
         "name": "vhost-vsock",
         "vring-align": 4096,
         "vring-desc": 5217370112,
         "signalled-used-valid": false,
         "vring-num-default": 128,
         "vring-avail": 5217372160,
         "queue-index": 1,
         "last-avail-idx": 0,
         "vring-used": 5217372480,
         "used-idx": 0,
         "vring-num": 128
     }
   }

Example:

Get VirtQueueStatus for virtio-serial (no vhost)

-> { "execute": "x-query-virtio-queue-status",
     "arguments": { "path": "/machine/peripheral-anon/device[0]/virtio-backend",
                    "queue": 20 }
   }
<- { "return": {
         "signalled-used": 0,
         "inuse": 0,
         "name": "virtio-serial",
         "vring-align": 4096,
         "vring-desc": 5182074880,
         "signalled-used-valid": false,
         "vring-num-default": 128,
         "vring-avail": 5182076928,
         "queue-index": 20,
         "last-avail-idx": 0,
         "vring-used": 5182077248,
         "used-idx": 0,
         "shadow-avail-idx": 0,
         "vring-num": 128
     }
   }

VirtVhostQueueStatus (Object)

Information of a vhost device’s vhost_virtqueue, including most members of the vhost_dev vhost_virtqueue data structure.

Members

name: string

Name of the VirtIODevice that uses this vhost_virtqueue

kick: int

vhost_virtqueue kick

call: int

vhost_virtqueue call

desc: int

vhost_virtqueue desc

avail: int

vhost_virtqueue avail

used: int

vhost_virtqueue used

num: int

vhost_virtqueue num

desc-phys: int

vhost_virtqueue desc_phys (descriptor area physical address)

desc-size: int

vhost_virtqueue desc_size

avail-phys: int

vhost_virtqueue avail_phys (driver area physical address)

avail-size: int

vhost_virtqueue avail_size

used-phys: int

vhost_virtqueue used_phys (device area physical address)

used-size: int

vhost_virtqueue used_size

Since

7.2

x-query-virtio-vhost-queue-status (Command)

Return information of a given vhost device’s vhost_virtqueue

Arguments

path: string

VirtIODevice canonical QOM path

queue: int

vhost_virtqueue index to examine

Features

unstable

This command is meant for debugging.

Returns

VirtVhostQueueStatus of the vhost_virtqueue

Since

7.2

Example: Get vhost_virtqueue status for vhost-crypto

 -> { "execute": "x-query-virtio-vhost-queue-status",
      "arguments": { "path": "/machine/peripheral/crypto0/virtio-backend",
                     "queue": 0 }
    }
 <- { "return": {
          "avail-phys": 5216124928,
          "name": "virtio-crypto",
          "used-phys": 5216127040,
          "avail-size": 2054,
          "desc-size": 16384,
          "used-size": 8198,
          "desc": 140141447430144,
          "num": 1024,
          "call": 0,
          "avail": 140141447446528,
          "desc-phys": 5216108544,
          "used": 140141447448640,
          "kick": 0
      }
    }

Example: Get vhost_virtqueue status for vhost-vsock

 -> { "execute": "x-query-virtio-vhost-queue-status",
      "arguments": { "path": "/machine/peripheral/vsock0/virtio-backend",
                     "queue": 0 }
    }
 <- { "return": {
          "avail-phys": 5182261248,
          "name": "vhost-vsock",
          "used-phys": 5182261568,
          "avail-size": 262,
          "desc-size": 2048,
          "used-size": 1030,
          "desc": 140141413580800,
          "num": 128,
          "call": 0,
          "avail": 140141413582848,
          "desc-phys": 5182259200,
          "used": 140141413583168,
          "kick": 0
      }
    }

VirtioRingDesc (Object)

Information regarding the vring descriptor area

Members

addr: int

Guest physical address of the descriptor area

len: int

Length of the descriptor area

flags: array of string

List of descriptor flags

Since

7.2

VirtioRingAvail (Object)

Information regarding the avail vring (a.k.a. driver area)

Members

flags: int

VRingAvail flags

idx: int

VRingAvail index

ring: int

VRingAvail ring[] entry at provided index

Since

7.2

VirtioRingUsed (Object)

Information regarding the used vring (a.k.a. device area)

Members

flags: int

VRingUsed flags

idx: int

VRingUsed index

Since

7.2

VirtioQueueElement (Object)

Information regarding a VirtQueue’s VirtQueueElement including descriptor, driver, and device areas

Members

name: string

Name of the VirtIODevice that uses this VirtQueue

index: int

Index of the element in the queue

descs: array of VirtioRingDesc

List of descriptors (VirtioRingDesc)

avail: VirtioRingAvail

VRingAvail info

used: VirtioRingUsed

VRingUsed info

Since

7.2

x-query-virtio-queue-element (Command)

Return the information about a VirtQueue’s VirtQueueElement

Arguments

path: string

VirtIODevice canonical QOM path

queue: int

VirtQueue index to examine

index: int (optional)

Index of the element in the queue (default: head of the queue)

Features

unstable

This command is meant for debugging.

Returns

VirtioQueueElement information

Since

7.2

Example: Introspect on virtio-net’s VirtQueue 0 at index 5

 -> { "execute": "x-query-virtio-queue-element",
      "arguments": { "path": "/machine/peripheral-anon/device[1]/virtio-backend",
                     "queue": 0,
                     "index": 5 }
    }
 <- { "return": {
          "index": 5,
          "name": "virtio-net",
          "descs": [
              {
                  "flags": ["write"],
                  "len": 1536,
                  "addr": 5257305600
              }
          ],
          "avail": {
              "idx": 256,
              "flags": 0,
              "ring": 5
          },
          "used": {
              "idx": 13,
              "flags": 0
          }
      }
    }

Example: Introspect on virtio-crypto’s VirtQueue 1 at head

 -> { "execute": "x-query-virtio-queue-element",
      "arguments": { "path": "/machine/peripheral/crypto0/virtio-backend",
                     "queue": 1 }
    }
 <- { "return": {
          "index": 0,
          "name": "virtio-crypto",
          "descs": [
              {
                  "flags": [],
                  "len": 0,
                  "addr": 8080268923184214134
              }
          ],
          "avail": {
              "idx": 280,
              "flags": 0,
              "ring": 0
          },
          "used": {
              "idx": 280,
              "flags": 0
          }
      }
    }

Example: Introspect on virtio-scsi’s VirtQueue 2 at head

 -> { "execute": "x-query-virtio-queue-element",
      "arguments": { "path": "/machine/peripheral-anon/device[2]/virtio-backend",
                     "queue": 2 }
    }
 <- { "return": {
          "index": 19,
          "name": "virtio-scsi",
          "descs": [
              {
                  "flags": ["used", "indirect", "write"],
                  "len": 4099327944,
                  "addr": 12055409292258155293
              }
          ],
          "avail": {
              "idx": 1147,
              "flags": 0,
              "ring": 19
          },
          "used": {
              "idx": 280,
              "flags": 0
          }
      }
    }

IOThreadVirtQueueMapping (Object)

Describes the subset of virtqueues assigned to an IOThread.

Members

iothread: string

the id of IOThread object

vqs: array of int (optional)

an optional array of virtqueue indices that will be handled by this IOThread. When absent, virtqueues are assigned round-robin across all IOThreadVirtQueueMappings provided. Either all IOThreadVirtQueueMappings must have vqs or none of them must have it.

Since

9.0

DummyVirtioForceArrays (Object)

Not used by QMP; hack to let us use IOThreadVirtQueueMappingList internally

Members

unused-iothread-vq-mapping: array of IOThreadVirtQueueMapping

Not documented

Since

9.0

GranuleMode (Enum)

Values

4k

granule page size of 4KiB

8k

granule page size of 8KiB

16k

granule page size of 16KiB

64k

granule page size of 64KiB

host

granule matches the host page size

Since

9.0

VFIO devices

QapiVfioMigrationState (Enum)

An enumeration of the VFIO device migration states.

Values

stop

The device is stopped.

running

The device is running.

stop-copy

The device is stopped and its internal state is available for reading.

resuming

The device is stopped and its internal state is available for writing.

running-p2p

The device is running in the P2P quiescent state.

pre-copy

The device is running, tracking its internal state and its internal state is available for reading.

pre-copy-p2p

The device is running in the P2P quiescent state, tracking its internal state and its internal state is available for reading.

Since

9.1

VFIO_MIGRATION (Event)

This event is emitted when a VFIO device migration state is changed.

Arguments

device-id: string

The device’s id, if it has one.

qom-path: string

The device’s QOM path.

device-state: QapiVfioMigrationState

The new changed device migration state.

Since

9.1

Example:

<- { "timestamp": { "seconds": 1713771323, "microseconds": 212268 },
     "event": "VFIO_MIGRATION",
     "data": {
         "device-id": "vfio_dev1",
         "qom-path": "/machine/peripheral/vfio_dev1",
         "device-state": "stop" } }

Cryptography devices

QCryptodevBackendAlgoType (Enum)

The supported algorithm types of a crypto device.

Values

sym

symmetric encryption

asym

asymmetric Encryption

Since

8.0

QCryptodevBackendServiceType (Enum)

The supported service types of a crypto device.

Values

cipher

Symmetric Key Cipher service

hash

Hash service

mac

Message Authentication Codes service

aead

Authenticated Encryption with Associated Data service

akcipher

Asymmetric Key Cipher service

Since

8.0

QCryptodevBackendType (Enum)

The crypto device backend type

Values

builtin

the QEMU builtin support

vhost-user

vhost-user

lkcf

Linux kernel cryptographic framework

Since

8.0

QCryptodevBackendClient (Object)

Information about a queue of crypto device.

Members

queue: int

the queue index of the crypto device

type: QCryptodevBackendType

the type of the crypto device

Since

8.0

QCryptodevInfo (Object)

Information about a crypto device.

Members

id: string

the id of the crypto device

service: array of QCryptodevBackendServiceType

supported service types of a crypto device

client: array of QCryptodevBackendClient

the additional information of the crypto device

Since

8.0

query-cryptodev (Command)

Returns information about current crypto devices.

Returns

a list of QCryptodevInfo

Since

8.0

CXL devices

CxlEventLog (Enum)

CXL has a number of separate event logs for different types of events. Each such event log is handled and signaled independently.

Values

informational

Information Event Log

warning

Warning Event Log

failure

Failure Event Log

fatal

Fatal Event Log

Since

8.1

cxl-inject-general-media-event (Command)

Inject an event record for a General Media Event (CXL r3.0 8.2.9.2.1.1). This event type is reported via one of the event logs specified via the log parameter.

Arguments

path: string

CXL type 3 device canonical QOM path

log: CxlEventLog

event log to add the event to

flags: int

Event Record Flags. See CXL r3.0 Table 8-42 Common Event Record Format, Event Record Flags for subfield definitions.

dpa: int

Device Physical Address (relative to path device). Note lower bits include some flags. See CXL r3.0 Table 8-43 General Media Event Record, Physical Address.

descriptor: int

Memory Event Descriptor with additional memory event information. See CXL r3.0 Table 8-43 General Media Event Record, Memory Event Descriptor for bit definitions.

type: int

Type of memory event that occurred. See CXL r3.0 Table 8-43 General Media Event Record, Memory Event Type for possible values.

transaction-type: int

Type of first transaction that caused the event to occur. See CXL r3.0 Table 8-43 General Media Event Record, Transaction Type for possible values.

channel: int (optional)

The channel of the memory event location. A channel is an interface that can be independently accessed for a transaction.

rank: int (optional)

The rank of the memory event location. A rank is a set of memory devices on a channel that together execute a transaction.

device: int (optional)

Bitmask that represents all devices in the rank associated with the memory event location.

component-id: string (optional)

Device specific component identifier for the event. May describe a field replaceable sub-component of the device.

Since

8.1

cxl-inject-dram-event (Command)

Inject an event record for a DRAM Event (CXL r3.0 8.2.9.2.1.2). This event type is reported via one of the event logs specified via the log parameter.

Arguments

path: string

CXL type 3 device canonical QOM path

log: CxlEventLog

Event log to add the event to

flags: int

Event Record Flags. See CXL r3.0 Table 8-42 Common Event Record Format, Event Record Flags for subfield definitions.

dpa: int

Device Physical Address (relative to path device). Note lower bits include some flags. See CXL r3.0 Table 8-44 DRAM Event Record, Physical Address.

descriptor: int

Memory Event Descriptor with additional memory event information. See CXL r3.0 Table 8-44 DRAM Event Record, Memory Event Descriptor for bit definitions.

type: int

Type of memory event that occurred. See CXL r3.0 Table 8-44 DRAM Event Record, Memory Event Type for possible values.

transaction-type: int

Type of first transaction that caused the event to occur. See CXL r3.0 Table 8-44 DRAM Event Record, Transaction Type for possible values.

channel: int (optional)

The channel of the memory event location. A channel is an interface that can be independently accessed for a transaction.

rank: int (optional)

The rank of the memory event location. A rank is a set of memory devices on a channel that together execute a transaction.

nibble-mask: int (optional)

Identifies one or more nibbles that the error affects

bank-group: int (optional)

Bank group of the memory event location, incorporating a number of Banks.

bank: int (optional)

Bank of the memory event location. A single bank is accessed per read or write of the memory.

row: int (optional)

Row address within the DRAM.

column: int (optional)

Column address within the DRAM.

correction-mask: array of int (optional)

Bits within each nibble. Used in order of bits set in the nibble-mask. Up to 4 nibbles may be covered.

Since

8.1

cxl-inject-memory-module-event (Command)

Inject an event record for a Memory Module Event (CXL r3.0 8.2.9.2.1.3). This event includes a copy of the Device Health info at the time of the event.

Arguments

path: string

CXL type 3 device canonical QOM path

log: CxlEventLog

Event Log to add the event to

flags: int

Event Record Flags. See CXL r3.0 Table 8-42 Common Event Record Format, Event Record Flags for subfield definitions.

type: int

Device Event Type. See CXL r3.0 Table 8-45 Memory Module Event Record for bit definitions for bit definiions.

health-status: int

Overall health summary bitmap. See CXL r3.0 Table 8-100 Get Health Info Output Payload, Health Status for bit definitions.

media-status: int

Overall media health summary. See CXL r3.0 Table 8-100 Get Health Info Output Payload, Media Status for bit definitions.

additional-status: int

See CXL r3.0 Table 8-100 Get Health Info Output Payload, Additional Status for subfield definitions.

life-used: int

Percentage (0-100) of factory expected life span.

temperature: int

Device temperature in degrees Celsius.

dirty-shutdown-count: int

Number of times the device has been unable to determine whether data loss may have occurred.

corrected-volatile-error-count: int

Total number of correctable errors in volatile memory.

corrected-persistent-error-count: int

Total number of correctable errors in persistent memory

Since

8.1

cxl-inject-poison (Command)

Poison records indicate that a CXL memory device knows that a particular memory region may be corrupted. This may be because of locally detected errors (e.g. ECC failure) or poisoned writes received from other components in the system. This injection mechanism enables testing of the OS handling of poison records which may be queried via the CXL mailbox.

Arguments

path: string

CXL type 3 device canonical QOM path

start: int

Start address; must be 64 byte aligned.

length: int

Length of poison to inject; must be a multiple of 64 bytes.

Since

8.1

CxlUncorErrorType (Enum)

Type of uncorrectable CXL error to inject. These errors are reported via an AER uncorrectable internal error with additional information logged at the CXL device.

Values

cache-data-parity

Data error such as data parity or data ECC error CXL.cache

cache-address-parity

Address parity or other errors associated with the address field on CXL.cache

cache-be-parity

Byte enable parity or other byte enable errors on CXL.cache

cache-data-ecc

ECC error on CXL.cache

mem-data-parity

Data error such as data parity or data ECC error on CXL.mem

mem-address-parity

Address parity or other errors associated with the address field on CXL.mem

mem-be-parity

Byte enable parity or other byte enable errors on CXL.mem.

mem-data-ecc

Data ECC error on CXL.mem.

reinit-threshold

REINIT threshold hit.

rsvd-encoding

Received unrecognized encoding.

poison-received

Received poison from the peer.

receiver-overflow

Buffer overflows (first 3 bits of header log indicate which)

internal

Component specific error

cxl-ide-tx

Integrity and data encryption tx error.

cxl-ide-rx

Integrity and data encryption rx error.

Since

8.0

CXLUncorErrorRecord (Object)

Record of a single error including header log.

Members

type: CxlUncorErrorType

Type of error

header: array of int

16 DWORD of header.

Since

8.0

cxl-inject-uncorrectable-errors (Command)

Command to allow injection of multiple errors in one go. This allows testing of multiple header log handling in the OS.

Arguments

path: string

CXL Type 3 device canonical QOM path

errors: array of CXLUncorErrorRecord

Errors to inject

Since

8.0

CxlCorErrorType (Enum)

Type of CXL correctable error to inject

Values

cache-data-ecc

Data ECC error on CXL.cache

mem-data-ecc

Data ECC error on CXL.mem

crc-threshold

Component specific and applicable to 68 byte Flit mode only.

retry-threshold

Retry threshold hit in the Local Retry State Machine, 68B Flits only.

cache-poison-received

Received poison from a peer on CXL.cache.

mem-poison-received

Received poison from a peer on CXL.mem

physical

Received error indication from the physical layer.

Since

8.0

cxl-inject-correctable-error (Command)

Command to inject a single correctable error. Multiple error injection of this error type is not interesting as there is no associated header log. These errors are reported via AER as a correctable internal error, with additional detail available from the CXL device.

Arguments

path: string

CXL Type 3 device canonical QOM path

type: CxlCorErrorType

Type of error.

Since

8.0

CxlDynamicCapacityExtent (Object)

A single dynamic capacity extent. This is a contiguous allocation of memory by Device Physical Address within a single Dynamic Capacity Region on a CXL Type 3 Device.

Members

offset: int

The offset (in bytes) to the start of the region where the extent belongs to.

len: int

The length of the extent in bytes.

Since

9.1

CxlExtentSelectionPolicy (Enum)

The policy to use for selecting which extents comprise the added capacity, as defined in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-70.

Values

free

Device is responsible for allocating the requested memory capacity and is free to do this using any combination of supported extents.

contiguous

Device is responsible for allocating the requested memory capacity but must do so as a single contiguous extent.

prescriptive

The precise set of extents to be allocated is specified by the command. Thus allocation is being managed by the issuer of the allocation command, not the device.

enable-shared-access

Capacity has already been allocated to a different host using free, contiguous or prescriptive policy with a known tag. This policy then instructs the device to make the capacity with the specified tag available to an additional host. Capacity is implicit as it matches that already associated with the tag. Note that the extent list (and hence Device Physical Addresses) used are per host, so a device may use different representations on each host. The ordering of the extents provided to each host is indicated to the host using per extent sequence numbers generated by the device. Has a similar meaning for temporal sharing, but in that case there may be only one host involved.

Since

9.1

cxl-add-dynamic-capacity (Command)

Initiate adding dynamic capacity extents to a host. This simulates operations defined in Compute Express Link (CXL) Specification, Revision 3.1, Section 7.6.7.6.5. Note that, currently, establishing success or failure of the full Add Dynamic Capacity flow requires out of band communication with the OS of the CXL host.

Arguments

path: string

path to the CXL Dynamic Capacity Device in the QOM tree.

host-id: int

The “Host ID” field as defined in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-70.

selection-policy: CxlExtentSelectionPolicy

The “Selection Policy” bits as defined in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-70. It specifies the policy to use for selecting which extents comprise the added capacity.

region: int

The “Region Number” field as defined in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-70. Valid range is from 0-7.

tag: string (optional)

The “Tag” field as defined in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-70.

extents: array of CxlDynamicCapacityExtent

The “Extent List” field as defined in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-70.

Features

unstable

For now this command is subject to change.

Since : 9.1

CxlExtentRemovalPolicy (Enum)

The policy to use for selecting which extents comprise the released capacity, defined in the “Flags” field in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-71.

Values

tag-based

Extents are selected by the device based on tag, with no requirement for contiguous extents.

prescriptive

Extent list of capacity to release is included in the request payload.

Since

9.1

cxl-release-dynamic-capacity (Command)

Initiate release of dynamic capacity extents from a host. This simulates operations defined in Compute Express Link (CXL) Specification, Revision 3.1, Section 7.6.7.6.6. Note that, currently, success or failure of the full Release Dynamic Capacity flow requires out of band communication with the OS of the CXL host.

Arguments

path: string

path to the CXL Dynamic Capacity Device in the QOM tree.

host-id: int

The “Host ID” field as defined in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-71.

removal-policy: CxlExtentRemovalPolicy

Bit[3:0] of the “Flags” field as defined in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-71.

forced-removal: boolean (optional)

Bit[4] of the “Flags” field in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-71. When set, the device does not wait for a Release Dynamic Capacity command from the host. Instead, the host immediately looses access to the released capacity.

sanitize-on-release: boolean (optional)

Bit[5] of the “Flags” field in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-71. When set, the device should sanitize all released capacity as a result of this request. This ensures that all user data and metadata is made permanently unavailable by whatever means is appropriate for the media type. Note that changing encryption keys is not sufficient.

region: int

The “Region Number” field as defined in Compute Express Link Specification, Revision 3.1, Table 7-71. Valid range is from 0-7.

tag: string (optional)

The “Tag” field as defined in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-71.

extents: array of CxlDynamicCapacityExtent

The “Extent List” field as defined in Compute Express Link (CXL) Specification, Revision 3.1, Table 7-71.

Features

unstable

For now this command is subject to change.

Since : 9.1