X Server crashes during log in VM since 16.04.2

[Gannet]

If I change screen resolution in my VM with Kubuntu 16.04.3 and then make log off and then log on X server is crashes doesn't able me to log in.

Please, look in Xorg.0.log.old for backtrace.

Also the appropriate report on freedesktop.org: https://bugs.freedesktop.org/show_bug.cgi?id=102554

Host:
Kubuntu 17.04
Linux 4.13.2
libvirt-bin 3.6.0
qemu 2.10

Guest:
Kubuntu 16.04.3
Linux 4.10.0-35-generic
xserver-xorg-video-qxl 0.1.4-3ubuntu3
xserver-common 1.18.4-0ubuntu0.3

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xserver-xorg (not installed)
ProcVersionSignature: Ubuntu 4.10.0-35.39~16.04.1-generic 4.10.17
Uname: Linux 4.10.0-35-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
CurrentDesktop: KDE
Date: Sat Sep 23 01:27:49 2017
InstallationDate: Installed on 2016-09-16 (371 days ago)
InstallationMedia: Kubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
JournalErrors:
 Error: command ['journalctl', '-b', '--priority=warning', '--lines=1000'] failed with exit code 1: Hint: You are currently not seeing messages from other users and the system.
       Users in the 'systemd-journal' group can see all messages. Pass -q to
       turn off this notice.
 No journal files were opened due to insufficient permissions.
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)

[Gannet (ken20001)]

Created attachment 133981
Xorg log file

Host:
Kubuntu 17.04
Linux 4.13
libvirt-bin 3.6.0
qemu 2.10

Guest:
Kubuntu 16.04.3
Linux 4.10.0-33-generic
xserver-xorg-video-qxl 0.1.4-3ubuntu3
xserver-common 1.18.4-0ubuntu0.3

If not to change default screen resolution 1280x1024 in VM, this issue is not happens. But if screen resolution has been changed to any other, crash happens while login (please, see the log in attachment). This issue started to happen from 16.04.2. In Kubuntu 16.04.1 all is OK.

[RussianNeuroMancer (russianneuromancer)]

Created attachment 133982
Xorg log from Kubuntu 17.10

Same issue on Kubuntu 17.04 guest and Kubuntu 17.10 guest. Log from Kubuntu 17.10 is attached.

Linux 4.12
X.Org Server 1.19.3
QXL DDX 0.1.5

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Gannet (ken20001)]

Any updates?

[Gannet (ken20001)]

Any updates?

[Gannet (ken20001)]

Created attachment 137737
Xorg log file with backtrace from Kubuntu 18.04 (development branch)

[Victor Toso (bugzilla-c)]

Have you filed the bug with (K)ubuntu? It would be good to know if they have patched with [0] as this was to solve bug with similar issue [1]

[0] https://cgit.freedesktop.org/xorg/driver/xf86-video-qxl/commit/
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1428340

[Gannet (ken20001)]

(In reply to Victor Toso from comment #4)
> Have you filed the bug with (K)ubuntu? It would be good to know if they have
> patched with [0] as this was to solve bug with similar issue [1]
>
> [0] https://cgit.freedesktop.org/xorg/driver/xf86-video-qxl/commit/
> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1428340

https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1719038

[Gannet (ken20001)]

Here is a patch which fixes the issue: https://cgit.freedesktop.org/xorg/driver/xf86-video-qxl/commit/?id=ee8f904ab0d590c741e640e9548c472e6a58b3cc

[Gannet (ken20001)]

Also I found the previous patch works only when qemu-guest-agent in not added to the VM, otherwise crash happens all the times while to login. It show window which informs that ksmserver is crashed and if to click "okay", it quits to sddm login screen.

[Gannet (ken20001)]

> [0] https://cgit.freedesktop.org/xorg/driver/xf86-video-qxl/commit/
I found this patch works only when qemu-guest-agent in not added to the VM, otherwise crash happens all the times while login. It shows the window which informs that ksmserver is crashed and if to click "okay", it quits to sddm login screen.

[Gitlab-migration (gitlab-migration)]

-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/spice/spice-gtk/issues/66.

[Gannet (ken20001)]

Moved from freedesktop to GitLab: https://gitlab.freedesktop.org/spice/spice-gtk/issues/66

[Andreas Hasenack (ahasenack)]

Upstream bug https://gitlab.freedesktop.org/spice/spice-gtk/issues/66 was closed, but if I understood it correctly, only for 18.04. Is this still an issue for 16.04, and does the patch from comment #5 help there?

[RussianNeuroMancer (russianneuromancer)]

> Is this still an issue for 16.04

Not for 16.04.0-16.04.2 as far I remember, but still issue for 16.0.3 and 16.04.4. I guess as soon as 16.04.5 get released this issue should be harder to reproduce, just like in 18.04 now.

[Gannet (ken20001)]

The issue still in 18.10 host and 18.04 VM. Please, look the attachment above.

[Christian Ehrhardt  (paelzer)]

Hi Gannet,
the discussion of RussianNeuroMancer with upstream ended trying to tackle the KDE resolution setting [1], but not a change in qemu/libvirt or other components of the virst-stack. Also it was reported that newer versions were less (or not)9 affected.

Is your case related to KDE as well, or do you have a more generic/easy reproducer to trigger this issue?

[1]: https://gitlab.freedesktop.org/spice/spice-gtk/issues/66

[Gannet (ken20001)]

Hello, Christian.
This issue is only reproducible with KDE in the guest. Just like that.