Comment 22 for bug 1822884

I'm still not really sure how the port binding stuff during live migration is working with the OSA->OSA live migrations but not the RDO stuff, I'm unsure what is updating the port's binding:host_id to the dest host before we call migrate_instance_finish in the OSA case but not the RDO case. Anyway, I for sure have a recreate in the cross-cell resize stuff so likely need Sean's fix anyway, and got the confirmation/details from Miguel in Neutron today on the difference between updating the port's binding:host_id indirectly by activating the dest host binding vs updating the port's binding:host_id directly to point at the dest host (when there is already an inactive dest host port binding). I guess I assumed those worked the same way, i.e. if you activate the inactive dest host port binding it updates the port's binding:host_id (works) and if you update the port's binding:host_id it would activate the dest host port binding (doesn't, and raises the error).

http://eavesdrop.openstack.org/irclogs/%23openstack-neutron/%23openstack-neutron.2019-05-09.log.html#t2019-05-09T20:40:18