libvirt users - May 2019 - VM display is blank when open (but Gnome Boxes thumbnails ok)

Hi,

I also posted this question on the IRC #virt channel but have not received
any reaction at the moment of posting this message to the mailing list.

Since I last turned off my laptop (Dell XPS-15-9570 running Ubuntu 19.04)
on Friday 10 May (I had to do it by long power press by the way), I am no
longer able to get the display of my VMs: I am getting a black screen, even
though I can see it running in the thumbnail of Gnome Boxes.
You can see the described behaviour on the following video capture:
https://youtu.be/Lv67g0foyzc.
Troubleshooting Log from Gnome Boxes is available here:
https://pastebin.com/9eWGYsJV.
It was working all properly on Friday before I turn off my laptop.

Any clue what could be wrong and how I could solve this issue (I digged the
Internet for 2 hours without success)?

Thanks in advance for your help!

Kind regards,

Michel

On Mon, May 13, 2019 at 04:40:55PM +0200, Michel Rozpendowski
wrote:
>Hi,
>
>I also posted this question on the IRC #virt channel but have not received
>any reaction at the moment of posting this message to the mailing list.
>
>Since I last turned off my laptop (Dell XPS-15-9570 running Ubuntu 19.04)
>on Friday 10 May (I had to do it by long power press by the way), I am no
>longer able to get the display of my VMs: I am getting a black screen, even
>though I can see it running in the thumbnail of Gnome Boxes.
>You can see the described behaviour on the following video capture:
>https://youtu.be/Lv67g0foyzc.
>Troubleshooting Log from Gnome Boxes is available here:
>https://pastebin.com/9eWGYsJV.
>It was working all properly on Friday before I turn off my laptop.
>
>Any clue what could be wrong and how I could solve this issue (I digged the
>Internet for 2 hours without success)?
>
>Thanks in advance for your help!
>
Well, sorry, I don't really know what might've caused it, but it looks
all kind
of OK from a libvirt standpoint, so my best guess would be something related to
the virtio graphics.  But the I saw you are turning off that VM, so I'm
guessing
it happens even after starting the VM back, right?  Still, might be worth asking
on qemu mailing lists if nobody on this list will know.
>Kind regards,
>
>Michel
>_______________________________________________
>libvirt-users mailing list
>libvirt-users@redhat.com
>https://www.redhat.com/mailman/listinfo/libvirt-users

On Mon, May 13, 2019 at 5:26 PM Martin Kletzander <mkletzan@redhat.com>
wrote:
> On Mon, May 13, 2019 at 04:40:55PM +0200, Michel Rozpendowski wrote:
> >Hi,
> >
> >I also posted this question on the IRC #virt channel but have not
received
> >any reaction at the moment of posting this message to the mailing list.
> >
> >Since I last turned off my laptop (Dell XPS-15-9570 running Ubuntu
19.04)
> >on Friday 10 May (I had to do it by long power press by the way), I am
no
> >longer able to get the display of my VMs: I am getting a black screen,
> even
> >though I can see it running in the thumbnail of Gnome Boxes.
> >You can see the described behaviour on the following video capture:
> >https://youtu.be/Lv67g0foyzc.
> >Troubleshooting Log from Gnome Boxes is available here:
> >https://pastebin.com/9eWGYsJV.
> >It was working all properly on Friday before I turn off my laptop.
> >
> >Any clue what could be wrong and how I could solve this issue (I digged
> the
> >Internet for 2 hours without success)?
> >
> >Thanks in advance for your help!
> >
>
> Well, sorry, I don't really know what might've caused it, but it
looks all
> kind
> of OK from a libvirt standpoint, so my best guess would be something
> related to
> the virtio graphics.  But the I saw you are turning off that VM, so I'm
> guessing
> it happens even after starting the VM back, right?  Still, might be worth
> asking
> on qemu mailing lists if nobody on this list will know.
>
Thanks! Great advice about qemu. I digged into that direction and found
following post (
https://www.linuxquestions.org/questions/slackware-14/black-screen-with-virt-manager-4175486301/)
where setting the the video model to QLX and the display type to SPICE
fixed the issue.
It worked for me!

SOLVED