Re: [PATCH v3] drm/virtio: add new virtio gpu capset definitions

[Dmitry Osipenko <dmitry.osipenko@collabora.com>]

On 10/19/23 02:25, Gurchetan Singh wrote:
> On Tue, Oct 10, 2023 at 9:41 PM Huang Rui <ray.huang@amd.com> wrote:
> 
>> On Tue, Oct 10, 2023 at 11:52:14PM +0800, Dmitry Osipenko wrote:
>>> On 10/10/23 18:40, Dmitry Osipenko wrote:
>>>> On 10/10/23 16:57, Huang Rui wrote:
>>>>> These definitions are used fro qemu, and qemu imports this marco in
>> the
>>>>> headers to enable gfxstream, venus, cross domain, and drm (native
>>>>> context) for virtio gpu. So it should add them even kernel doesn't use
>>>>> this.
>>>>>
>>>>> Signed-off-by: Huang Rui <ray.huang@amd.com>
>>>>> Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
>>>>> ---
>>>>>
>>>>> Changes V1 -> V2:
>>>>> - Add all capsets including gfxstream and venus in kernel header
>> (Dmitry Osipenko)
>>>>>
>>>>> Changes V2 -> V3:
>>>>> - Add missed capsets including cross domain and drm (native context)
>>>>>   (Dmitry Osipenko)
>>>>>
>>>>> v1:
>> https://lore.kernel.org/lkml/20230915105918.3763061-1-ray.huang@amd.com/
>>>>> v2:
>> https://lore.kernel.org/lkml/20231010032553.1138036-1-ray.huang@amd.com/
>>>>>
>>>>>  include/uapi/linux/virtio_gpu.h | 4 ++++
>>>>>  1 file changed, 4 insertions(+)
>>>>>
>>>>> diff --git a/include/uapi/linux/virtio_gpu.h
>> b/include/uapi/linux/virtio_gpu.h
>>>>> index f556fde07b76..240911c8da31 100644
>>>>> --- a/include/uapi/linux/virtio_gpu.h
>>>>> +++ b/include/uapi/linux/virtio_gpu.h
>>>>> @@ -309,6 +309,10 @@ struct virtio_gpu_cmd_submit {
>>>>>
>>>>>  #define VIRTIO_GPU_CAPSET_VIRGL 1
>>>>>  #define VIRTIO_GPU_CAPSET_VIRGL2 2
>>>>> +#define VIRTIO_GPU_CAPSET_GFXSTREAM 3
>>>>
>>>> The GFXSTREAM capset isn't correct, it should be GFXSTREAM_VULKAN in
>>>> accordance to [1] and [2]. There are more capsets for GFXSTREAM.
>>>>
>>>> [1]
>>>>
>> https://github.com/google/crosvm/blob/main/rutabaga_gfx/src/rutabaga_utils.rs#L172
>>>>
>>>> [2]
>>>>
>> https://patchwork.kernel.org/project/qemu-devel/patch/20231006010835.444-7-gurchetansingh@chromium.org/
>>>
>>> Though, maybe those are "rutabaga" capsets that not related to
>>> virtio-gpu because crosvm has another defs for virtio-gpu capsets [3].
>>> The DRM capset is oddly missing in [3] and code uses "rutabaga" capset
>>> for DRM and virtio-gpu.
>>>
>>> [3]
>>>
>> https://github.com/google/crosvm/blob/main/devices/src/virtio/gpu/protocol.rs#L416
>>
>> Yes, [3] is the file that I referred to add these capsets definitions. And
>> it's defined as gfxstream not gfxstream_vulkan.
>>
>>>
>>> Gurchetan, could you please clarify which capsets definitions are
>>> related to virtio-gpu and gfxstream. The
>>> GFXSTREAM_VULKAN/GLES/MAGMA/COMPOSER or just the single GFXSTREAM?
> 
> 
> It should be GFXSTREAM_VULKAN.  The rest are more experimental and easy to
> modify in terms of the enum value, should the need arise.
> 
> I imagine the virtio-spec update to reflect the GFXSTREAM to
> GFXSTREAM_VULKAN change will happen eventually.

Thanks for the clarification. Good point about the spec updating, we
should document DRM context too,

-- 
Best regards,
Dmitry