Yeah @Boris - it really seems to be an issue bound to the Merom/Penryn processor generation.
I asked Andreas to check through some kernels and qemu versions so that we maybe eventually can consider bisecting something. But that will take a bit of time. Of course everyone able to spend some time can consider checking a few kernels of [1] as well (probably the easiest test to begin with). Still if there is an x86-microarchitecture expert out there that say "ah penryn, I know we added/dropped ... " please speak up :-) [1]: https://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1866870 Title: KVM Guest pauses after upgrade to Ubuntu 20.04 Status in QEMU: New Status in qemu package in Ubuntu: Incomplete Bug description: Symptom: Error unpausing domain: internal error: unable to execute QEMU command 'cont': Resetting the Virtual Machine is required Traceback (most recent call last): File "/usr/share/virt-manager/virtManager/asyncjob.py", line 75, in cb_wrapper callback(asyncjob, *args, **kwargs) File "/usr/share/virt-manager/virtManager/asyncjob.py", line 111, in tmpcb callback(*args, **kwargs) File "/usr/share/virt-manager/virtManager/object/libvirtobject.py", line 66, in newfn ret = fn(self, *args, **kwargs) File "/usr/share/virt-manager/virtManager/object/domain.py", line 1311, in resume self._backend.resume() File "/usr/lib/python3/dist-packages/libvirt.py", line 2174, in resume if ret == -1: raise libvirtError ('virDomainResume() failed', dom=self) libvirt.libvirtError: internal error: unable to execute QEMU command 'cont': Resetting the Virtual Machine is required --- As outlined here: https://bugs.launchpad.net/qemu/+bug/1813165/comments/15 After upgrade, all KVM guests are in a default pause state. Even after forcing them off via virsh, and restarting them the guests are paused. These Guests are not nested. A lot of diganostic information are outlined in the previous bug report link provided. The solution mentioned in previous report had been allegedly integrated into the downstream updates. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1866870/+subscriptions