On 2024/11/6 23:50, Christian König wrote: > Am 06.11.24 um 04:20 schrieb Chen, Jiqian: >> On 2024/11/5 21:42, Christian König wrote: >>> Am 05.11.24 um 07:05 schrieb Jiqian Chen: >>>> VPCI of Xen doesn't support resizable bar. When discrete GPU is used on >>>> PVH dom0 which using the VPCI, amdgpu fails to probe, so we need to >>>> disable this capability for PVH dom0. >>> What do you mean VPCI doesn't support resizeable BAR? >> VPCI is a virtual pci of Xen hypervisor used for PVH dom0, it is worked to >> emulate and process pci devices configuration space access, all that access >> will trap into Xen and handled by VPCI. >> But the Resizable Bars capability is not emulated now. > > That must be changed or otherwise you will run into more problems on hotplug > for example. > >>> This is mandatory to be supported or otherwise general PCI resource >>> assignment won't work either. >>> >>> In other words you can't hotplug something if that here doesn't work either. >> Yes, once I added dGPU to Xen PVH dom0, it didn't work unless I added this >> patch to return success for Rebar. > > That's only the tip of the iceberg. You are trying to mitigate symptoms > instead of fixing the underlying problem. > > So clear NAK from my side for this approach.
OK, I will try to find a solution on the Xen side and remove this patch from my series. Thanks. > > Regards, > Christian. > >>> Regards, >>> Christian. >>> >>>> Signed-off-by: Jiqian Chen <jiqian.c...@amd.com> >>>> Reviewed-by: Huang Rui <ray.hu...@amd.com> >>>> --- >>>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 4 ++++ >>>> 1 file changed, 4 insertions(+) >>>> >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c >>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c >>>> index b3fb92bbd9e2..012feb3790dd 100644 >>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c >>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c >>>> @@ -1619,6 +1619,10 @@ int amdgpu_device_resize_fb_bar(struct >>>> amdgpu_device *adev) >>>> if (!IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT)) >>>> return 0; >>>> + /* Bypass for PVH dom0 which doesn't support resizable bar */ >>>> + if (xen_initial_domain() && xen_pvh_domain()) >>>> + return 0; >>>> + >>>> /* Bypass for VF */ >>>> if (amdgpu_sriov_vf(adev)) >>>> return 0; > -- Best regards, Jiqian Chen.
