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

[Patrick O'Callaghan]

On Fri, 2017-11-24 at 17:53 +0000, Patrick O'Callaghan wrote:
> 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.

Back to QXL video, which now works. Windows was very confused about how
many screens it had - it was displaying on both, showing all menus and
open windows only on the virt-manager window and also showing the
desktop on the passthrough screen, but in the settings dialogue it
insisted it could only detect one display, even though I could move the
mouse cursor from one to the other.

It seems to have settled down now, but I'm reluctant to touch anything
for fear of breaking it again.

poc