During the pre live migration process, Nova performs most of the
tasks related to the creation and operation of the VM in the destination
host. That is done without interrupting any of the hardware in the source
host. If the pre_live_migration fails, those same operations should be
rolled back.
Currently nova is sharing the _rollback_live_migration for both
live and pre_live migration rollbacks, and that is causing the source
host to try to re-attach network interfaces on the source host where
they weren't actually de-attached.
This patch fixes that by adding a conditional to allow nova to do
different paths for migration and pre_live_migration rollbacks.
Closes-bug: #1944619
Change-Id: I784190ac356695dd508e0ad8ec31d8eaa3ebee56
Erlon R. Cruz