GPU passthrough support for Stoney [Radeon R2/R3/R4/R5 Graphics]?

[Alex Deucher]

On Wed, May 15, 2019 at 2:26 PM Micah Morton <mortonm at chromium.org> wrote:
>
> Hi folks,
>
> I'm interested in running a VM on a system with an integrated Stoney
> [Radeon R2/R3/R4/R5 Graphics] card and passing through the graphics
> card to the VM using the IOMMU. I'm wondering whether this is feasible
> and supposed to be doable with the right setup (as opposed to passing
> a discrete GPU to the VM, which I think is definitely doable?).
>
> So far, I can do all the qemu/kvm/vfio/iommu stuff to run the VM and
> pass the integrated GPU to it, but the drm driver in the VM fails
> during amdgpu_device_init(). Specifically, the logs show the SMU being
> unresponsive, which leads to a 'SMU firmware load failed' error
> message and kernel panic. I can share VM logs and the invocation of
> qemu and such if helpful, but first wanted to know at a high level if
> this should be feasible?
>
> P.S.: I'm not initializing the GPU in the host bios or host kernel at
> all, so I should be passing a fresh GPU to the VM. Also, I'm pretty
> sure I'm running the correct VGA bios for this GPU in the guest VM
> bios before guest boot.
>
> Any comments/suggestions would be appreciated!

It should work in at least once as long as your vm is properly set up.
Note that the driver needs access to the vbios image in the guest to
get device specific configuration details (clocks, display connector
configuration, etc.).

Alex