David: Indeed ! How stupid I am. I missed the root cause inside QUEMU log file. This was clear enough... error: kvm run failed Device or resource busy This is probably because your SMT is enabled.
So I switch SMT (Power Simultaneous Multi-Threading) off and now it's OK; VMs are running and installing. It had been years since I last touched KVM on Power and I lost my reflexes. So please forget my precedent comment telling I had the same issue on Power platform. It was similar symptoms but not the same problem. -- 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: Invalid Status in qemu package in Ubuntu: Invalid Status in seabios package in Ubuntu: Fix Released 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