[libvirt] sending openvswitch "port db" info during libvirt migration

[Laine Stump]

Someone asked on IRC the other day about sending openvswitch per-port
data (normally stored in the switch) to the destination host during a
migration. I suggested maybe this could be handled by encoding the
information into the interface's <virtualport> prior to migration, and
then writing it back out to openvswitch on the destination when the
interface was reconnected there.

I think there's a problem with that, though - they don't want to save
the port data on the source until the instant that the interface is
disconnected (since it is constantly changing), but by then the domain
XML has already long ago been formatted and sent to the destination.

So is there some other way within the confines of the current migration
protocol that this information can be sent from migration source to
destination?