Windows aarch64 support

[bbqsrc]

Windows has supported the aarch64 architecture for a while now. Is there anything on the roadmap to support Windows images?

[edigaryev]

Since Tart is using Apple's Virtualization.Framework under the hood, we're limited to the devices already implemented by that framework.

As a result, support for Windows can only happen when either (1) Virtualization.Framework implements/emulates devices needed for proper Windows functioning, or (2) Windows implements drivers needed to run in virtualized Apple Silicon environments.

[bbqsrc]

But, it is possible! I have been using aarch64 Windows on macOS using hvf with qemu:

qemu-system-aarch64 \
  -M virt \
  -cpu host \
  -accel hvf \
  -m 6G \
  -smp 2 \
  -device ramfb \
  -bios /opt/homebrew/opt/qemu/share/qemu/edk2-aarch64-code.fd \
  -device qemu-xhci,id=xhci \
  -device usb-kbd \
  -device usb-tablet \
  -drive file=win11-aarch64.iso,media=cdrom,if=none,id=inst \
  -device usb-storage,drive=inst,bus=xhci.0 \
  -drive file=./Win11.qcow2,id=root,format=qcow2,if=none \
  -device usb-storage,drive=root,bus=xhci.0 \
  -nic user,model=virtio-net-pci,mac=2A:50:A7:4E:D9:C4 \
  -audiodev coreaudio,id=coreaudio,out.frequency=48000 \
  -audio coreaudio \
  -device usb-audio

[edigaryev]

But, it is possible!

It is possible with Hypervisor.Framework (which QEMU uses on Darwin), yes.

However, using Hypervisor.Framework in Tart means we have to implement all the Virtual I/O and other devices ourselves. This is a relatively big task.

Also, there's no feature parity between Virtualization.Framework and Hypervisor.Framework: you cannot run macOS guests using Hypervisor.Framework. Same if we were to simply invoke QEMU commands from Tart.

It's possible to combine more than one framework/program invocation in Tart indeed, but a more in-depth investigation is needed on how the overall UX of Tart will be affected and whether the additional complexity will be worth it.

[bbqsrc]

Oh, I'm sorry! I did not even notice that Hypervisor.framework and Virtualization.framework are different frameworks.

This makes sense then.