It turns out this is because of a kernel bug (see https://www.mail- archive.com/linux-ker...@vger.kernel.org/msg1152720.html).
A workaround to to add qxl.modeset=0 in /etc/default/grub for the kernel commandline. After update-grub and reboot CPU usage is back to being reasonable. This also fixes the problem mentioned in the above email thread where even when using virt-viewer QXL multihead fails to report more than one availble display. With qxl.modeset=0 virt-viewer correctly allows you to turn on up to four virtual displays. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1571918 Title: Constant high cpu usage in xenial under qxl/spice To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/1571918/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
