VMApple machine emulation

VMApple is the device model that the macOS built-in hypervisor called “Virtualization.framework” exposes to Apple Silicon macOS guests. The “vmapple” machine model in QEMU implements the same device model, but does not use any code from Virtualization.Framework.

Prerequisites

To run the vmapple machine model, you need to

• Run on Apple Silicon

• Run on macOS 12.0 or above

• Have an already installed copy of a Virtualization.Framework macOS 12 virtual machine. Note that newer versions than 12.x are currently NOT supported on the guest side. I will assume that you installed it using the macosvm CLI.

First, we need to extract the UUID from the virtual machine that you installed. You can do this by running the shell script in contrib/vmapple/uuid.sh on the macosvm.json file.

uuid.sh script to extract the UUID from a macosvm.json file

$ contrib/vmapple/uuid.sh "path/to/macosvm.json"

Now we also need to trim the aux partition. It contains metadata that we can just discard:

Command to trim the aux file

$ dd if="aux.img" of="aux.img.trimmed" bs=$(( 0x4000 )) skip=1

How to run

Then, we can launch QEMU with the Virtualization.Framework pre-boot environment and the readily installed target disk images. I recommend to port forward the VM’s ssh and vnc ports to the host to get better interactive access into the target system:

Example execution command line

$ UUID="$(contrib/vmapple/uuid.sh 'macosvm.json')"
$ AVPBOOTER="/System/Library/Frameworks/Virtualization.framework/Resources/AVPBooter.vmapple2.bin"
$ AUX="aux.img.trimmed"
$ DISK="disk.img"
$ qemu-system-aarch64 \
     -serial mon:stdio \
     -m 4G \
     -accel hvf \
     -M vmapple,uuid="$UUID" \
     -bios "$AVPBOOTER" \
     -drive file="$AUX",if=pflash,format=raw \
     -drive file="$DISK",if=pflash,format=raw \
     -drive file="$AUX",if=none,id=aux,format=raw \
     -drive file="$DISK",if=none,id=root,format=raw \
     -device vmapple-virtio-blk-pci,variant=aux,drive=aux \
     -device vmapple-virtio-blk-pci,variant=root,drive=root \
     -netdev user,id=net0,ipv6=off,hostfwd=tcp::2222-:22,hostfwd=tcp::5901-:5900 \
     -device virtio-net-pci,netdev=net0