Comment 5 for bug 1624997

Below configurations have been used to work around the problem:

 1. Edit /etc/nova/nova.conf on nova nodes which participate in the live migration:

 [libvirt]
 rbd_user =
 rbd_secret_uuid =
 #live_migration_uri = qemu+ssh://%s/system
 live_migration_uri = qemu+tcp://%s/system

 # Disable tunnelled migration so that selective
 # live block migration can be supported.
 live_migration_tunnelled = True

 iscsi_use_multipath = True

 2. Edit /etc/libvirt/libvirtd.conf:
 listen_tcp = 1
 listen_addr = "0.0.0.0"
 auth_tcp = "none"

 3. Restart nova-compute and libvirt:
 # service libvirt-bin restart
 # service nova-compute restart

Meanwhile, such modifications won't work if you are using Ubuntu with kernel 3.x like 3.13.0-100-generic I previously used - it seems there is a kernel bug underground. Latest kernel 4.4.0-45-generic work well with above mentioned configurations.