[vfio-users] IGD passthrough on UEFI platforms

[Dmitry Fleytman]

> On 3 Jan 2018, at 16:00, Alex Williamson <alex.williamson at redhat.com> wrote:
> 
> On Wed, 3 Jan 2018 10:09:49 +0200
> Dmitry Fleytman <dmitry.fleytman at gmail.com <mailto:dmitry.fleytman at gmail.com>> wrote:
> 
>> 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,
> 
> You're on the right track with providing a ROM from another system, but
> IGD ROMs don't typically "just work", try rom-fixer on it to fix the
> device ID and checksum and make sure rom-parser reports a legacy ROM
> section:
> 
> https://github.com/awilliam/rom-parser <https://github.com/awilliam/rom-parser>
> 
> I've made IGD assignment work on a UEFI Lenovo laptop by temporarily
> booting a legacy OS, dumping the IGD ROM, booting back to UEFI, fixing
> the ROM, then passing it to QEMU via the file option.  Thanks,

Thanks, Alex! We will try.

> 
> Alex

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