--- fixes: - | During the Caracal cycle the libvirt driver was enhanced to support using device aliases to detach devices from a domain. I1dfe4ad3df81bc810835af9b09cfc6c06e9a5388 This introduced a regression for instance with vgpus. A prior bugfix https://bugs.launchpad.net/nova/+bug/1942345 addressed the symptom without correcting the underlying problem. A related bug for mdev devices was later reported. https://bugs.launchpad.net/nova/+bug/2074219 When this feature was added nova introduced a helper method to get device via the alias because the libvirt api does not provide one natively. That helper function assumed all devices would have an alias attribute. That assumption was not valid and had now been corrected. As a result detaching a volume from an instance with vgpus should now be possible and this class of bug should no longer happen.