Merge "Fix LM rollback w/o multi port bindings extension" into stable/yoga

Author: Zuul

nova/tests/functional/regressions/test_bug_1888395.py

@@ -146,12 +146,7 @@ def test_live_migration_rollback(self):
 
         self.assertFalse(
             self.neutron_api.has_port_binding_extension(self.ctxt))
-        # FIXME(artom) Until bug 1969980 is fixed, this will fail with a
-        # NotImplementedError.
-        self._live_migrate(self.server, migration_expected_state='error',
-                           server_expected_state='ERROR')
-        server = self.api.get_server(self.server['id'])
-        self.assertIn(
-            "NotImplementedError: Cannot load 'vifs' in the base class",
-            server['fault']['details']
-        )
+        # NOTE(artom) The live migration will still fail (we fail it in
+        # _migrate_stub()), but the server should correctly rollback to ACTIVE.
+        self._live_migrate(self.server, migration_expected_state='failed',
+                           server_expected_state='ACTIVE')

nova/virt/libvirt/driver.py

@@ -10469,10 +10469,13 @@ def rollback_live_migration_at_source(self, context, instance,
         :param instance:  the instance being migrated
         :param migrate_date: a LibvirtLiveMigrateData object
         """
-        network_info = network_model.NetworkInfo(
-            [vif.source_vif for vif in migrate_data.vifs
-                            if "source_vif" in vif and vif.source_vif])
-        self._reattach_instance_vifs(context, instance, network_info)
+        # NOTE(artom) migrate_data.vifs might not be set if our Neutron doesn't
+        # have the multiple port bindings extension.
+        if 'vifs' in migrate_data and migrate_data.vifs:
+            network_info = network_model.NetworkInfo(
+                [vif.source_vif for vif in migrate_data.vifs
+                                if "source_vif" in vif and vif.source_vif])
+            self._reattach_instance_vifs(context, instance, network_info)
 
     def rollback_live_migration_at_destination(self, context, instance,
                                                network_info,