During live-migration stress testing we are seeing the following log:
Error from libvirt during undefine. Code=42 Error=Domain not found
There appears to be a race while trying to undefine the domain, and
something else is possibly also doing some kind of clean up. While this
does paper over that race, it stops otherwise completed live-migrations
from failing. It also matches similar error handling done for when
deleting the domain.
The next part of the bug fix is to ensure if we have any similar
unexpected errors during this later phase of the live-migration we don't
leave the instance stuck in the migrating state, it should move to an
ERROR state. This is covered in a follow on patch.
(cherry picked from commit