[Intel-gfx] [PATCH v14 5/7] vfio: ABI for mdev display dma-buf operation

[Gerd Hoffmann]

On Fri, 2017-08-18 at 18:21 +0800, Tina Zhang wrote:
> +/**
> + * VFIO_DEVICE_QUERY_GFX_PLANE - _IOW(VFIO_TYPE, VFIO_BASE + 14,
> struct vfio_device_query_gfx_plane)
> + *
> + * Set the drm_plane_type and flags, then retrieve information about
> the gfx plane.
> + *
> + * flags:
> + *     VFIO_GFX_PLANE_TYPE_PROBE and VFIO_GFX_PLANE_TYPE_DMABUF are
> set to ask if the mdev
> + *         supports dma-buf. 0 on support, -EINVAL on no support for
> dma-buf.
> + *      VFIO_GFX_PLANE_TYPE_PROBE and VFIO_GFX_PLANE_TYPE_REGION are
> set to ask if the mdev
> + *          supports region. 0 on support, -EINVAL on no support for
> region.
> + *      VFIO_GFX_PLANE_TYPE_DMABUF or VFIO_GFX_PLANE_TYPE_REGION is
> set with each call to
> + *          query the plane info.
> + *      Others are invalid and return -EINVAL.
> + *
> + * Return: 0 on success, -ENODEV with all out fields zero on mdev
> device initialization,

Do you mean PROBE calls here?

The behavior in case the guest driver hasn't yet initialized the plane 
should be documented here too.

cheers,
  Gerd