Currently associating a vm with a host fails for all compute resources but for Ovirt.
The reason is that to do the association we make a query based on the ip or mac attributes of the Host, which are now in its own model.

...Host.authorized(:view_hosts, Host).where(:ip...

Fix should be as simple as performing the 'where' on the interfaces instead of the host and a couple of tests ensuring this won't break again.