[PATCH] drm/amdgpu/gmc: use PCI BARs for APUs in passthrough

[Alex Deucher]

On Wed, Mar 16, 2022 at 11:52 AM Michel Dänzer
<michel.daenzer at mailbox.org> wrote:
>
> On 2022-03-11 18:43, Michel Dänzer wrote:
> > On 2022-03-11 11:32, Christian König wrote:
> >> Am 11.03.22 um 11:24 schrieb Michel Dänzer:
> >>> On 2022-03-10 19:06, Alex Deucher wrote:
> >>>> If the GPU is passed through to a guest VM, use the PCI
> >>>> BAR for CPU FB access rather than the physical address of
> >>>> carve out.  The physical address is not valid in a guest.
> >>> I think amdgpu_device_flush_hdp & amdgpu_device_invalidate_hdp need to be modified accordingly.
> >
> > I'm surprised you gave your R-b despite this. Surely the HDP cache needs to be handled when going through the BAR?
>
> I'm a bit confused why there's still been no response on this point from either of you. Are you guys checking internally whether or not this is needed?

Yes, it is needed.  I added it in v2 of the patch.

Alex

>
>
> --
> Earthling Michel Dänzer            |                  https://redhat.com
> Libre software enthusiast          |         Mesa and Xwayland developer