[vfio-users] IGD passthrough on UEFI platforms

[Dmitry Fleytman]

Hello All,

We're evaluating possibility of using IGD passthrough in legacy mode using Apple laptops, like Macbook Air as a h/w platform.

Apple laptops are using UEFI boot, according to lspci the options rom is disabled:
[virtual] Expansion ROM at 000c0000 [disabled] [size=128K]

As a result when trying to launch QEMU IGD passthrough, the following error is encountered:
qemu-system-x86_64: -device vfio-pci,host=00:02.0,id=hostdev0,bus=pci.0,addr=0x2: IGD device 0000:00:02.0 has no ROM, legacy mode disabled

We tried to supply VBIOS binaries dumped from another platform with the same graphics adaptor, but that did not work either:  “legacy mode disabled” error disappeared but the picture did not show up on the screen.

Therefore, we would like to ask a number of questions:

  - What in your opinion would be the best way to make IGD passthrough working on hardware like this?
  - For UEFI only OSes, like MacOS, what are the missing parts required to support UEFI VM with IGD passthrough?

Your thoughts are welcome,
Dmitry