Hi William,
You can have several logical networks on the same interface. If
ovirtmgmt is not a vm network you can even mix tagged and untagged
networks (if not, you can't mix). You don's have to do anything besides
creating the logical networks in ovirt and assign them to the interface,
ovirt takes care of creating the virtual interfaces it needs.
What you can't do is have more than one logical network per vlan (I
think there's a feature request on this, I know I've asked it on the
list:-) ).
Regards,