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

[Gerd Hoffmann]

  Hi,

> 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.

Ok, we certainly have the same situation with intel.  When the guest
driver is not loaded (yet) there is no valid surface.

We should cleanly define what the ioctl should do in that case, so all
drivers behave the same way.

I'd suggest that all fields defining the surface (drm_format, width,
height, stride, size) should be set to zero in that case.

cheers,
  Gerd