Mouse starts jumping wildly on guest desktop

[johannes]

Sometimes mouse goes completely crazy and starts jumping around the guest desktop by itself and becomes completely unusable.

This does not happen on every boot, only sometimes. It may be caused by some input combination but I haven't yet found any specific cause. It happens soon after the desktop has been loaded and rebooting seems to be the only way to resolve the situation.

Guest: Kubuntu 20.04 64-bit (live), with KDE desktop
Host: Arch Linux, with KDE desktop
QEMU version: 5.1.0

QEMU start command:
qemu-system-x86_64 -enable-kvm -m 6G -cpu host -smp 3 -cdrom ./linux/kubuntu-20.04-desktop-amd64.iso -boot d -vga virtio -soundhw hda -display sdl,gl=on

[Thomas Huth (th-huth)]

The QEMU project is currently moving its bug tracking to another system.
For this we need to know which bugs are still valid and which could be
closed already. Thus we are setting the bug state to "Incomplete" now.

If the bug has already been fixed in the latest upstream version of QEMU,
then please close this ticket as "Fix released".

If it is not fixed yet and you think that this bug report here is still
valid, then you have two options:

1) If you already have an account on gitlab.com, please open a new ticket
for this problem in our new tracker here:

    https://gitlab.com/qemu-project/qemu/-/issues

and then close this ticket here on Launchpad (or let it expire auto-
matically after 60 days). Please mention the URL of this bug ticket on
Launchpad in the new ticket on GitLab.

2) If you don't have an account on gitlab.com and don't intend to get
one, but still would like to keep this ticket opened, then please switch
the state back to "New" or "Confirmed" within the next 60 days (other-
wise it will get closed as "Expired"). We will then eventually migrate
the ticket automatically to the new system (but you won't be the reporter
of the bug in the new system and thus you won't get notified on changes
anymore).

Thank you and sorry for the inconvenience.

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]