Re: [PATCH v2 1/2] drm/virtio: Don't attach GEM to a non-created context in gem_object_open()

[Rob Clark]

On Tue, Apr 1, 2025 at 5:39 AM Dmitry Osipenko
<dmitry.osipenko@xxxxxxxxxxxxx> wrote:
>
> The vfpriv->ctx_id is always initialized to a non-zero value. Check whether
> context was created before attaching GEM to this context ID. This left
> unnoticed previously because host silently skips attachment if context
> doesn't exist, still we shouldn't do that for consistency.
>
> Fixes: 086b9f27f0ab ("drm/virtio: Don't create a context with default param if context_init is supported")
> Cc: <stable@xxxxxxxxxxxxxxx> # v6.14+
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>

Reviewed-by: Rob Clark <robdclark@xxxxxxxxx>

> ---
>  drivers/gpu/drm/virtio/virtgpu_gem.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c b/drivers/gpu/drm/virtio/virtgpu_gem.c
> index 5aab588fc400..3d6aa26fdb53 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_gem.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
> @@ -115,13 +115,14 @@ int virtio_gpu_gem_object_open(struct drm_gem_object *obj,
>         if (!vgdev->has_context_init)
>                 virtio_gpu_create_context(obj->dev, file);
>
> -       objs = virtio_gpu_array_alloc(1);
> -       if (!objs)
> -               return -ENOMEM;
> -       virtio_gpu_array_add_obj(objs, obj);
> +       if (vfpriv->context_created) {
> +               objs = virtio_gpu_array_alloc(1);
> +               if (!objs)
> +                       return -ENOMEM;
> +               virtio_gpu_array_add_obj(objs, obj);
>
> -       if (vfpriv->ctx_id)
>                 virtio_gpu_cmd_context_attach_resource(vgdev, vfpriv->ctx_id, objs);
> +       }
>
>  out_notify:
>         virtio_gpu_notify(vgdev);
> --
> 2.49.0
>