[Intel-gfx] refactor the i915 GVT support

[Gerd Hoffmann]

  Hi,

> https://github.com/intel/gvt-linux/blob/topic/gvt-xengt/drivers/gpu/drm/i915/gvt/xengt.c

> But it's hard for some customers to contribute their own "hypervisor"
> module to the upstream Linux kernel. I am thinking what would be a
> better solution here? The MPT layer in the kernel helps a lot for
> customers, but only one open-source "hypervisor" module is there in
> the kernel. That can confuse people which don't know the story.  One
> thing I was thinking is to put a document about the background and
> more description in the MPT headers. So it won't confuse more people. 

Getting the xengt module linked above merged into mainline
would also nicely explain why there are hypervisor modules.

take care,
  Gerd