[vfio-users] amd gpu quirks and command line options

[Kyle Marek]

I am also experiencing the reset bug with a XFX-manufactured Vega 64, an
AMD FX-9590 on an ASUS M5A99FX PRO R2.0. I plan to compile kernels and
QEMU from their trunks, try on a known-working Intel computer (while I
still have it), and report back with more information.

I just wanted to point out that there is another user who cannot reset
their Vega 64 on a non-Threadripper CPU...

On 10/04/2018 12:38 AM, Allen Dial wrote:
> Thank you Alex,
>
>
> I really appreciate your help!
>
>
> Allen
>
>
> On Oct 03, 2018, at 09:42 AM, Alex Williamson
> <alex.williamson at redhat.com> wrote:
>
>
> On Wed, 03 Oct 2018 15:13:47 +0000 (GMT)
> Allen Dial <adial at mac.com> wrote:
>
> Questions:
> 1. Is there a known command line, vfio, or grub statemnet that will
> allow this passed through gpu to work after guest shutdown or resart
> without requireing a state change of the host?
>
> None that I'm aware of.
>
>
> 2. Are vfio or qemu "quirks" items that can help in situations like
> these and are "quirks" configurable or initializable somehow?
>
> There are numerous quirks in vfio and QEMU, and I encourage vendors to
> add more, but they're generally made to work automatically for the
> devices where they apply. We have some quirks for the older Bonaire
> and Hawaii AMD GPUs, but nothing for the more recent ones. IIRC there
> were some patches in the amdgpu driver to help reset the card, but that
> probably only helps for a Linux guest, or perhaps if you bind the device
> back to the amdgpu driver in the host.
>
>
> 3. Is there a place where I can go to reference all of the vfio
> related kernel options and or paramaters that can be set and is there
> a description of each of the possible options/parameters and how to
> use them?
>
> You can run modinfo on the vfio kernel options, there's not a lot there
> though. In QEMU you can see the device options via '-device
> vfio-pci,?'. In both cases, most of the options are for debugging, but
> ask for anything you're not sure of. QEMU doesn't provide a way to
> describe the options. In general, AMD folks tend to deny that there
> are reset issues, so except for the Bonaire/Hawaii quirks above where
> they admit there's a silicon issue, we haven't gotten much support for
> additional quirks. Thanks,
>
> Alex