[libvirt] Question about save and restore OVS per-port data in live migration

Hi When we try to migrate a guest with 12 NICs, we find libvirt will try to get per-port data in finish phase, it makes the guest paused for several hundred milliseconds. qemuMigrationCookieAddNetwork -> virNetDevOpenvswitchGetMigrateData for per-nic -> run 'ovs-vsctl --if-exists get Interface vnetx external_ids:Port' (about 25ms) In our case, there's no portData available and it seems there is no need to run the cmd. Questions: 1. Is it necessary to get/set per-port data in migration finish phase? It will increase the downtime. 2. Is there any way (i.e. a switch) to not run the OVS cmd if there's no portData available?