Live migration with XenServer as hypervisor failed with xapi
errors "VIF_NOT_IN_MAP". There are two reasons for this
problem:
(1) Before XS7.0, it supports VM live migration without
setting vif_ref and network_ref explicitly if the destination
host has same network, but since XS7.0, it doesn't support
this way, we must give vif_ref and network_ref mapping.
(2) In nova, XenServer has introduced interim network for
fixing ovs updating wrong port in neutron, see bug 1268955
and also interim network can assist support neutron security
group (linux bridge) as we cannot make VIF connected to
linux bridge directly via XAPI
To achieve this, we will add {src_vif_ref: dest_network_ref}
mapping information, in pre_live_migration, we first create
interim network in destination host and store
{neutron_vif_uuid: dest_network_ref} in migrate_data, then in
source host, before live_migration, we will calculate the
{src_vif_ref: dest_network_ref} and set it as parameters to
xapi when calling VM.migrate_send. Also, we will handle the
case where the destination host is running older code that
doesn't have this new src_vif_ref mapping, like live migrating
from an Ocata compute node to a Newton compute node.
Closes-bug: 1658877
Change-Id: If0fb5d764011521916fbbe15224f524a220052f3
(cherry picked from commit 4cd32645fb)
ef0c67934c