[PATCH] drm/amd/amdgpu: Not request init data for MS_HYPERV with vega10

[Michael Kelley (LINUX)]

From: Alex Deucher <alexdeucher at gmail.com> Sent: Tuesday, April 12, 2022 7:13 AM
> 
> On Tue, Apr 12, 2022 at 4:01 AM Paul Menzel <pmenzel at molgen.mpg.de> wrote:
> >
> > [Cc: +x86 folks]
> >
> > Dear Alex, dear x86 folks,
> >
> >
> > x86 folks, can you think of alternatives to access `X86_HYPER_MS_HYPERV`
> > from `arch/x86/include/asm/hypervisor.h` without any preprocessor ifdef-ery?
> 
> I don't really see what problem that solves.  X86_HYPER_MS_HYPERV is
> an X86 thing.  Why do we need a processor agnostic way to handle it?
> Any code related to that is X86 specific.
> 
> Alex

Try using hv_is_hyperv_initialized() without any #ifdef'ery.  If
CONFIG_HYPERV is defined, it will tell you if you are running as a guest
on Hyper-V on x86/x64 or on ARM64.  If CONFIG_HYPERV is not defined,
it will return "false".

You'll need to #include <asm/mshyperv.h>.

Michael

> 
> >
> >
> > Am 11.04.22 um 18:28 schrieb Alex Deucher:
> > > On Mon, Apr 11, 2022 at 11:28 AM Paul Menzel wrote:
> >
> > […]
> >
> > >> Am 11.04.22 um 15:59 schrieb Yongqiang Sun:
> > >>> MS_HYPERV with vega10 doesn't have the interface to process
> > >>> request init data msg.
> > >>
> > >> Should some Hyper-V folks be added to the reviewers list too?
> > >>
> > >>> Check hypervisor type to not send the request for MS_HYPERV.
> > >>
> > >> Please add a blank line between paragraphs.
> > >>
> > >>> Signed-off-by: Yongqiang Sun <yongqiang.sun at amd.com>
> > >>> ---
> > >>>    drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c | 12 ++++++++++--
> > >>>    1 file changed, 10 insertions(+), 2 deletions(-)
> > >>>
> > >>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
> > >>> index 933c41f77c92..56b130ec44a9 100644
> > >>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
> > >>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
> > >>> @@ -23,6 +23,10 @@
> > >>>
> > >>>    #include <linux/module.h>
> > >>>
> > >>> +#ifdef CONFIG_X86
> > >>> +#include <asm/hypervisor.h>
> > >>> +#endif
> > >>> +
> > >>>    #include <drm/drm_drv.h>
> > >>>
> > >>>    #include "amdgpu.h"
> > >>> @@ -721,8 +725,12 @@ void amdgpu_detect_virtualization(struct
> amdgpu_device *adev)
> > >>>                        break;
> > >>>                case CHIP_VEGA10:
> > >>>                        soc15_set_virt_ops(adev);
> > >>> -                     /* send a dummy GPU_INIT_DATA request to host on vega10 */
> > >>> -                     amdgpu_virt_request_init_data(adev);
> > >>> +#ifdef CONFIG_X86
> > >>> +                     /* not send GPU_INIT_DATA with MS_HYPERV*/
> > >>> +                     if (hypervisor_is_type(X86_HYPER_MS_HYPERV) == false)
> > >>> +#endif
> > >>
> > >> Why guard everything with CONFIG_X86? (If it’s needed, it should be done
> > >> in C code.)
> > >
> > > X86_HYPER_MS_HYPERV only available on x86.
> >
> > Sorry, I missed the X86 dependency when quickly looking at the Hyper-V
> > stub IOMMU driver `drivers/iommu/hyperv-iommu.c`, but missed that
> > `HYPERV_IOMMU` has `depends on HYPERV && X86`.
> >
> >
> > Kind regards,
> >
> > Paul
> >
> >
> > >>> +                             /* send a dummy GPU_INIT_DATA request to host on vega10 */
> > >>> +                             amdgpu_virt_request_init_data(adev);
> > >>>                        break;
> > >>>                case CHIP_VEGA20:
> > >>>                case CHIP_ARCTURUS:
> > >>
> > >>
> > >> Kind regards,
> > >>
> > >> Paul