[libvirt] [PATCH 0/3] sample: vfio mdev display devices.

[Gerd Hoffmann]

On Thu, Apr 26, 2018 at 03:44:15AM +0000, Tian, Kevin wrote:
> > From: Alex Williamson
> > Sent: Thursday, April 19, 2018 2:32 AM
> > 
> > That almost begins to look reasonable, but then we can only expose this
> > for mdev devices, what if we were to hack a back door into a directly
> > assigned GPU that tracks the location of active display in the
> > framebuffer and implement the GFX_PLANE interface for that?  We have no
> > sysfs representation for either the template or the actual device for
> > anything other than mdev.  This inconsistency with physically assigned
> > devices has been one of my arguments against enhancing mdev sysfs.
> 
> One possible option is to wrap directly assigned GPU into a mdev. The
> parent driver could be a dummy PCI driver which does basic PCI
> initialization, and then provide hooks for vendor-specific hack. 

Thowing amdgpu into the mix.  Looks they have vgpu support too, but
using sriov instead of mdev.  Having VFIO_GFX support surely looks
useful there.  Adding a mdev dependency to the VFIO_GFX api would makes
things more complicated there for (IMHO) no good reason ...

cheers,
  Gerd