@wkitty42: Since the security update was for AMD processors - are you running on Intel or AMD?
Note: I marked this regression-update and we should keep and work under that urgency unless we can prove otherwise. I spawned a set of 64 bit guests on: 2.0.0+dfsg-2ubuntu1.42 Then I upgraded to 2.0.0+dfsg-2ubuntu1.43 The guests still start fine. Then I upgraded all else which e.g. meant also a related change in libvirt. => Still working fine. I only had an Intel host thou, so it might be important to learn if you run on AMD hardware and if that might be a prereq to be affected? The requested /proc/cpuinfo will have all that. Also in addition to the Kernel Panic getting the guest log could be useful in case qemu has thrown warnigns or errors. Summarizing, please provide: HW Info - cat /proc/cpuinfo - sudo dmidecode Logs: - journalctl -xe - cat /var/log/libvirt/qemu/<guestname>.log - dmesg Collect the logs right after the guest crashed please. ** Changed in: qemu (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1776575 Title: 14.04.5 safe-upgrade from QEMU 2.0.0+dfsg-2ubuntu1.42 to QEMU 2.0.0 +dfsg-2ubuntu1.43 kernel panics amd64 VM guests To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1776575/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs