Re: [PATCH v8 1/4] drm/virtio-gpu: Add VIRTIO_GPU_CAPSET_ROCM capability

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] virtio-gpu: premature UAPI exposure of unfinalized capability ID
- [Low] virtio-gpu: missing DRM UAPI alias for ROCM capability set
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commit a394228d77eeafc9f1dcc36150380f8561f1ee49
Author: Honglei Huang <honghuan@amd.com>

drm/virtio-gpu: Add VIRTIO_GPU_CAPSET_ROCM capability

This commit adds a new GPU capability set VIRTIO_GPU_CAPSET_ROCM with ID 8 
to support ROCm compute workloads. The commit message notes that the 
matching virtio-gpu specification change is currently in progress.

> diff --git a/include/uapi/linux/virtio_gpu.h b/include/uapi/linux/virtio_gpu.h
> index 4f530d90058c7..3d4dfadc9d789 100644
> --- a/include/uapi/linux/virtio_gpu.h
> +++ b/include/uapi/linux/virtio_gpu.h
> @@ -321,6 +321,7 @@ struct virtio_gpu_cmd_submit {
>  #define VIRTIO_GPU_CAPSET_VENUS 4
>  #define VIRTIO_GPU_CAPSET_CROSS_DOMAIN 5
>  #define VIRTIO_GPU_CAPSET_DRM 6
> +#define VIRTIO_GPU_CAPSET_ROCM 8

[Severity: Medium]
Is it safe to expose this speculative capability ID to userspace before the
virtio-gpu specification is finalized?

The commit message states the specification change for ID 8 is in progress.
Because the Linux UAPI is frozen once released, exposing this ID now could
permanently commit the kernel to ID 8 for ROCm. If the OASIS virtio
technical committee assigns a different ID or rejects the proposal, would
this leave the Linux UAPI permanently incompatible with the standard?

[Severity: Low]
Also, should there be a corresponding DRM UAPI alias added for this capability
set?

Previous capability sets have matching definitions in virtgpu_drm.h, such as
VIRTGPU_DRM_CAPSET_VENUS and VIRTGPU_DRM_CAPSET_DRM. Without adding a similar
VIRTGPU_DRM_CAPSET_ROCM alias, userspace DRM clients relying on virtgpu_drm.h
for the DRM_IOCTL_VIRTGPU_GET_CAPS ioctl will lack the necessary constant to
query ROCm capabilities natively.

>  /* VIRTIO_GPU_CMD_GET_CAPSET_INFO */
>  struct virtio_gpu_get_capset_info {

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Sashiko AI review · https://sashiko.dev/#/patchset/20260918095940.2253018-1-honghuan@amd.com?part=1