Re: [PATCH 00/12] Introduce new vmapple machine type

[Mads Ynddal]

> On 15 Jun 2023, at 00.40, Alexander Graf <graf@amazon.com> wrote:
> 
> This patch set introduces a new ARM and HVF specific machine type
> called "vmapple". It mimicks the device model that Apple's proprietary
> Virtualization.Framework exposes, but implements it in QEMU.
> 
> With this new machine type, you can run macOS guests on Apple Silicon
> systems via HVF. To do so, you need to first install macOS using
> Virtualization.Framework onto a virtual disk image using a tool like
> macosvm (https://github.com/s-u/macosvm)
> 
>  $ macosvm --disk disk.img,size=32g --aux aux.img \
>            --restore UniversalMac_12.0.1_21A559_Restore.ipsw vm.json
> 
> Then, extract the ECID from the installed VM:
> 
>  $ cat "$DIR/macosvm.json" | python3 -c                                 \
>  'import json,sys;obj=json.load(sys.stdin);print(obj["machineId"]) |    \
>  base64 -d | plutil -extract ECID raw -

Beware, that the file will be called 'vm.json' and DIR is undefined following
the previous line. Also, it's missing a single-quote at the end of
`["machineId"])`.

> In addition, cut off the first 16kb of the aux.img:
> 
>  $ dd if=aux.img of=aux.img.trimmed bs=$(( 0x4000 )) skip=1
> 
> Now, you can just launch QEMU with the bits generated above:
> 
>  $ qemu-system-aarch64 -serial mon:stdio                                \
>  -m 4G                                                                  \
>  -M vmapple,uuid=6240349656165161789                                    \
>  -bios /Sys*/Lib*/Fra*/Virtualization.f*/R*/AVPBooter.vmapple2.bin      \
>  -pflash aux.img.trimmed                                                \
>  -pflash disk.img                                                       \
>  -drive file=disk.img,if=none,id=root                                   \
>  -device virtio-blk-pci,drive=root,x-apple-type=1                       \
>  -drive file=aux.img.trimmed,if=none,id=aux                             \
>  -device virtio-blk-pci,drive=aux,x-apple-type=2                        \
>  -accel hvf -no-reboot

Just for clarity, I'd add that the 'vmapple,uuid=...' has to be set to the
ECID the previous step.

You haven't defined a display, but I'm not sure if that is on purpose to
show a minimal setup. I had to add '-display sdl' for it to fully work.

> There are a few limitations with this implementation:
> 
>  - Only runs on macOS because it relies on
>    ParavirtualizesGraphics.Framework
>  - Something is not fully correct on interrupt delivery or
>    similar - the keyboard does not work
>  - No Rosetta in the guest because we lack the private
>    entitlement to enable TSO

Would it be possible to mitigate the keyboard issue using an emulated USB
keyboard? I tried poking around with it, but with no success.

> Over time, I hope that some of the limitations above could cease to exist.
> This device model would enable very nice use cases with KVM on an Asahi
> Linux device.