I've tested smoe more cmbinations and found that I van have v4.2 work on focal. Eventually I have realized that when I install start the qemu from Ubuntu not only that but also the formerly working build of v4.2.0 from git start to fail (without rebuilding).
A bit of package bisect later I found seabios to be related. Focal is at 1.13.0-1 Eoan is at 1.12.0-1 After I knew that I verified and found it really only triggers on seabios 1.13.0. With 1.13 I was also able to break the qemu v4.0.0 git build on eoan. As well as the packaged qemu in Eoan. So it seems we are actually looking for a problem of seabios (instead of qemu) with the Penryn chip. I'll look at their changelog and bisect that tomorrow as time permits -- 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