[libvirt] [RFC PATCH 0/7] Enable vfio-pci 'property' for mediated devices

Gerd Hoffmann kraxel at redhat.com
Tue Jun 5 09:52:03 UTC 2018


  Hi,

> > TL;DR:
> > - we have a new attribute value for vfio-pci mediated devices called 'display'
> >     -> devices can now format this new 'display=on/off' property to the cmdline

Good.

> > - if user enables the vfio display (display=on) but doesn't enable OpenGL for
> >     Spice, we automatically assume the usage of '-display egl-headless'

Hmm, I think it would be better to have egl-headless explicitly
configured in the domain xml instead of doing it automagically depending
on configuration.

First, I'd prefer to allow non-opengl configuration for vfio displays.
nvidia has its own non-standard ways of doing things, which causes
problems now and then, so I'd like to have an easy way out in case
using egl-headless on nvidia fails to work properly.

It's a bit ugly that we have to depend on qemu throwing errors in case
the vfio display uses dma-bufs (and therefore requires opengl) then
because libvirt can't easily probe the vfio display type.

Second, you can use egl-headless for other use cases too, for example to
use virgl with vnc.

cheers,
  Gerd




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