Comment 5 for bug 1759924

Per comment 2 on cleaning up the port when we shelve offload, it sounds like that should be OK to do:

(2:30:17 PM) mriedem: mlavalle: while working on bug 1759924 - i'm trying to determine if neutron would have any issues with a port attached to a vm where the binding host and device_owner are unset?
(2:30:19 PM) openstack: bug 1759924 in OpenStack Compute (nova) "Port device owner isn't updated with new host availability zone during unshelve" [Medium,Triaged] https://launchpad.net/bugs/1759924 - Assigned to Matt Riedemann (mriedem)
(2:30:44 PM) mriedem: can you think of anything off the top of your head that might break there?
(2:30:58 PM) mriedem: this is when an instance is shelved, meaning there is no actual guest running in a hypervisor
(2:34:07 PM) mlavalle: mriedem: in that situation the port is not bound so it doesn't exist in a host. Am I understanding correctly?
(2:34:44 PM) mriedem: correct, nova would unplug the vif
(2:34:45 PM) mriedem: during shelve
(2:34:53 PM) mriedem: the port is still logically attached to the instance in the db
(2:34:58 PM) mriedem: but there is nothing in the data plane
(2:35:17 PM) mlavalle: I don't think it would be a problem. it's just and unbound port, a row in a DB table
(2:35:19 PM) openstackgerrit: Merged openstack/networking-bagpipe master: bagpipe-bgp: IPVPN MPLS OVS driver, silently ignore re-removal https://review.openstack.org/559658
(2:35:25 PM) mriedem: mlavalle: ok, cool, thanks

But it could be done separately from the unshelve fix to update the device_owner.