Re: [PATCH v10] vfio: ABI for mdev display dma-buf operation

[Kirti Wankhede]

On 7/14/2017 5:35 PM, Gerd Hoffmann wrote:
>   Hi,
> 
>> There could be only two planes, one DRM_PLANE_TYPE_PRIMARY and one
>> DRM_PLANE_TYPE_CURSOR.
>> Steps from gfx_update for region case would be:
>> - VFIO_DEVICE_QUERY_GFX_PLANE with plane_type =
>> DRM_PLANE_TYPE_PRIMARY
> 
>> - if vfio_device_gfx_plane_info.size > 0, read region for primary
>> surface and update console surface
> 
> Why?  I suspect you want notify the caller whenever the surface has
> been updated or not?  If so we should add an explicit flag or field for
> that.
> 

No need of flag here. If vGPU driver is not loaded in the guest, there
is no surface being managed by vGPU, in that case this size will be zero.

Thanks,
Kirti