[vfio-users] VM has no display [SOLVED - NOT]

[Patrick O'Callaghan]

On Thu, 2017-11-23 at 23:55 +0000, Patrick O'Callaghan wrote:
> On Thu, 2017-11-23 at 17:57 +0000, Patrick O'Callaghan wrote:
> > While experimenting with display settings inside Windows 10, trying to
> > get it to not duplicate the display between the host console and guest
> > monitor (the two displays have recently started duplicating each other,
> > which they didn't used to do; this may be related to my updating to
> > Fedora 27 but I'm not aware of changing anything intentionally) I have
> > managed to get it to not display on either, which I didn't know was
> > even possible.
> > 
> > Since my Win10 installation is on a raw drive, I dual-booted and after
> > some grumbling from Windows about "getting devices ready", it booted,
> > using the 2nd GPU. However back in VM-mode under virt-manager I still
> > get no display, neither on the console window nor on switching monitor
> > input to the 2nd GPU. I tried again, this time telling Windows to
> > duplicate the displays (i.e. attempting to get back to where I was) but
> > that hasn't worked.
> > 
> > My setup uses the default QXL video, PS/2 mouse and virtio keyboard,
> > all of which have been working up till now. 
> 
> I changed the video from QXL to virtio and magically it started working
> again. This is without touching anything in Windows.

And now it stopped again. The *only* change I made was to try to add a
2nd USB mouse to overcome the lag problems I've mentioned in another
thread. On rebooting, the guest screen was blank, i.e. did not show the
Windows login box or background image, but *did* show the mouse cursor
for the new mouse and allowed me to move it around. I just couldn't do
anything with it.

After reverting the change and removing the 2nd mouse, it's still
broken in the same way, except now the cursor moves with my usual
mouse.

I'm speculating that it's not actually possible to get deterministic
behaviour out of this thing ...

poc