[RFC PATCH 6/6] drm/i915/gvt: support QEMU getting the dmabuf

[Gerd Hoffmann]

  Hi,

> >We could also do it the other way around:  Instead of having the kernel returning
> 
> >the plane description userspace could pass it in, and the kernel throws -EINVAL in
> 
> >case it doesn't match due to things having changed meanwhile.
> 
> Or just return a dmabuf  based on the current plane ?

If gvt is able to hand out dma-bufs for inactive planes, then yes, we
can do this.  Have one ioctl where we pass in the plane id, get back a
plane description struct, and another where we pass in the plane
description struct and get back a dma-buf fd.

cheers,
  Gerd