Also seen in a Train grenade job here:

http://logs.openstack.org/07/668707/1/gate/nova-grenade-live-migration/a07496c/logs/screen-n-cpu.txt.gz?level=TRACE#_Jul_08_17_55_21_915336

Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: WARNING nova.virt.libvirt.driver [None req-7e57acd7-a044-4acd-96dc-ce5f91e32afd None None] [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a] Error monitoring migration: Timed out during operation: cannot acquire state change lock (held by remoteDispatchDomainMigratePerform3Params): libvirtError: Timed out during operation: cannot acquire state change lock (held by remoteDispatchDomainMigratePerform3Params)
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a] Traceback (most recent call last):
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]   File "/opt/stack/new/nova/nova/virt/libvirt/driver.py", line 8165, in _live_migration
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]     finish_event, disk_paths)
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]   File "/opt/stack/new/nova/nova/virt/libvirt/driver.py", line 7955, in _live_migration_monitor
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]     info = guest.get_job_info()
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]   File "/opt/stack/new/nova/nova/virt/libvirt/guest.py", line 698, in get_job_info
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]     stats = self._domain.jobStats()
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]   File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 190, in doit
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]     result = proxy_call(self._autowrap, f, *args, **kwargs)
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]   File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 148, in proxy_call
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]     rv = execute(f, *args, **kwargs)
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]   File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 129, in execute
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]     six.reraise(c, e, tb)
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]   File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 83, in tworker
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]     rv = meth(*args, **kwargs)
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]   File "/usr/local/lib/python2.7/dist-packages/libvirt.py", line 1403, in jobStats
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]     if ret is None: raise libvirtError ('virDomainGetJobStats() failed', dom=self)
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a] libvirtError: Timed out during operation: cannot acquire state change lock (held by remoteDispatchDomainMigratePerform3Params)
Jul 08 17:55:21.915336 ubuntu-bionic-rax-iad-0008752810 nova-compute[1203]: ERROR nova.virt.libvirt.driver [instance: 1d85e89c-7a1b-4b85-b831-77277f70c75a]