[PATCH v6 4/6] vfio: Define vfio based vgpu's dma-buf operations

[Gerd Hoffmann]

> struct vfio_vgpu_surface_info {
>         __u64 start;
>         __u32 width;
>         __u32 height;
>         __u32 stride;
>         __u32 size;
>         __u32 x_pos;
>         __u32 y_pos;
>         __u32 padding;
>         /* Only used when VFIO_VGPU_SURFACE_DMABUF_* flags set */
>         __u64 drm_format_mod;
>         __u32 drm_format;

Why for dmabufs only?  Shouldn't the region specify the format too? 
Even in case you are using a fixed one (say DRM_FORMAT_XRGB8888) you
can explicitly say so in drm_format (and set drm_format_mod to zero).

cheers,
  Gerd