Merge "libvirt: slow live-migration to ensure network is ready" into stable/queens17.0.3

3 files changed, 264 insertions, 31 deletions

diff --git a/nova/tests/unit/virt/libvirt/test_driver.py b/nova/tests/unit/virt/libvirt/test_driver.py
index 80cce802f7..8c1620b074 100644
--- a/nova/tests/unit/virt/libvirt/test_driver.py
+++ b/nova/tests/unit/virt/libvirt/test_driver.py
@@ -8939,7 +8939,7 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         vdmock = self.mox.CreateMock(fakelibvirt.virDomain)
         guest = libvirt_guest.Guest(vdmock)
         self.mox.StubOutWithMock(vdmock, "migrateToURI2")
-        _bandwidth = CONF.libvirt.live_migration_bandwidth
+        _bandwidth = libvirt_driver.MIN_MIGRATION_SPEED_BW
         vdmock.XMLDesc(flags=fakelibvirt.VIR_DOMAIN_XML_MIGRATABLE).AndReturn(
                 initial_xml)
         vdmock.migrateToURI2(drvr._live_migration_uri('dest'),
@@ -8961,7 +8961,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         self.assertRaises(fakelibvirt.libvirtError,
                           drvr._live_migration_operation,
                           self.context, instance_ref, 'dest',
-                          False, migrate_data, guest, [])
+                          False, migrate_data, guest, [],
+                          _bandwidth)
 
     def test_live_migration_parallels_no_new_xml(self):
         self.flags(virt_type='parallels', group='libvirt')
@@ -8976,12 +8977,14 @@ class LibvirtConnTestCase(test.NoDBTestCase,
             block_migration=False)
         dom_mock = mock.MagicMock()
         guest = libvirt_guest.Guest(dom_mock)
+        _bandwidth = libvirt_driver.MIN_MIGRATION_SPEED_BW
         drvr._live_migration_operation(self.context, instance, 'dest',
-                                       False, migrate_data, guest, [])
+                                       False, migrate_data, guest, [],
+                                       bandwidth=_bandwidth)
         # when new xml is not passed we fall back to migrateToURI
         dom_mock.migrateToURI.assert_called_once_with(
             drvr._live_migration_uri('dest'),
-            flags=0, bandwidth=0)
+            flags=0, bandwidth=_bandwidth)
 
     @mock.patch.object(utils, 'spawn')
     @mock.patch.object(host.Host, 'get_guest')
@@ -9003,10 +9006,13 @@ class LibvirtConnTestCase(test.NoDBTestCase,
                               'power_state': power_state.RUNNING,
                               'vm_state': vm_states.ACTIVE})
         instance = objects.Instance(**instance_dict)
+        instance.info_cache = objects.InstanceInfoCache(
+            network_info=_fake_network_info(self, 1))
         migrate_data = objects.LibvirtLiveMigrateData(
             block_migration=True)
         dom = fakelibvirt.Domain(drvr._get_connection(), '<domain/>', True)
         guest = libvirt_guest.Guest(dom)
+        guest.migrate_configure_max_speed = mock.MagicMock()
         mock_guest.return_value = guest
         drvr._live_migration(self.context, instance, 'dest',
                              lambda: None, lambda: None, True,
@@ -9015,7 +9021,9 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         mock_thread.assert_called_once_with(
             drvr._live_migration_operation,
             self.context, instance, 'dest', True,
-            migrate_data, guest, [])
+            migrate_data, guest, [], libvirt_driver.MIN_MIGRATION_SPEED_BW)
+        guest.migrate_configure_max_speed.assert_called_once_with(
+            CONF.libvirt.live_migration_bandwidth)
 
     def test_live_migration_update_volume_xml(self):
         self.compute = manager.ComputeManager()
@@ -9067,7 +9075,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
             test_mock.XMLDesc.return_value = target_xml
             self.assertFalse(drvr._live_migration_operation(
                              self.context, instance_ref, 'dest', False,
-                             migrate_data, guest, []))
+                             migrate_data, guest, [],
+                             libvirt_driver.MIN_MIGRATION_SPEED_BW))
             mupdate.assert_called_once_with(
                 guest, migrate_data, mock.ANY)
 
@@ -9107,6 +9116,7 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
         test_mock = mock.MagicMock()
         guest = libvirt_guest.Guest(test_mock)
+        _bandwidth = libvirt_driver.MIN_MIGRATION_SPEED_BW
 
         with mock.patch.object(libvirt_migrate,
                                'get_updated_guest_xml') as mupdate:
@@ -9114,11 +9124,11 @@ class LibvirtConnTestCase(test.NoDBTestCase,
             test_mock.XMLDesc.return_value = target_xml
             drvr._live_migration_operation(self.context, instance_ref,
                                            'dest', False, migrate_data,
-                                           guest, [])
+                                           guest, [], _bandwidth)
             test_mock.migrateToURI2.assert_called_once_with(
                 'qemu+tcp://127.0.0.2/system',
                 miguri='tcp://127.0.0.2',
-                dxml=mupdate(), flags=0, bandwidth=0)
+                dxml=mupdate(), flags=0, bandwidth=_bandwidth)
 
     def test_update_volume_xml(self):
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
@@ -9383,7 +9393,7 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         mock_migrate.side_effect = fakelibvirt.libvirtError("ERR")
 
         # start test
-        bandwidth = CONF.libvirt.live_migration_bandwidth
+        bandwidth = libvirt_driver.MIN_MIGRATION_SPEED_BW
         migrate_data = objects.LibvirtLiveMigrateData(
             graphics_listen_addr_vnc='10.0.0.1',
             graphics_listen_addr_spice='10.0.0.2',
@@ -9398,7 +9408,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         self.assertRaises(fakelibvirt.libvirtError,
                           drvr._live_migration_operation,
                           self.context, instance_ref, 'dest',
-                          False, migrate_data, guest, [])
+                          False, migrate_data, guest, [],
+                          bandwidth=bandwidth)
         mock_xml.assert_called_once_with(
                 flags=fakelibvirt.VIR_DOMAIN_XML_MIGRATABLE)
         mock_migrate.assert_called_once_with(
@@ -9430,7 +9441,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         self.assertRaises(exception.MigrationError,
                           drvr._live_migration_operation,
                           self.context, instance_ref, 'dest',
-                          False, migrate_data, guest, [])
+                          False, migrate_data, guest, [],
+                          bandwidth=libvirt_driver.MIN_MIGRATION_SPEED_BW)
 
     @mock.patch.object(host.Host, 'has_min_version', return_value=True)
     @mock.patch.object(fakelibvirt.virDomain, "migrateToURI3")
@@ -9445,7 +9457,7 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         disk_paths = ['vda', 'vdb']
         params = {
             'migrate_disks': ['vda', 'vdb'],
-            'bandwidth': CONF.libvirt.live_migration_bandwidth,
+            'bandwidth': libvirt_driver.MIN_MIGRATION_SPEED_BW,
             'destination_xml': '',
         }
         mock_migrateToURI3.side_effect = fakelibvirt.libvirtError("ERR")
@@ -9467,7 +9479,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         self.assertRaises(fakelibvirt.libvirtError,
                           drvr._live_migration_operation,
                           self.context, instance, 'dest',
-                          False, migrate_data, guest, disk_paths)
+                          False, migrate_data, guest, disk_paths,
+                          libvirt_driver.MIN_MIGRATION_SPEED_BW)
         mock_migrateToURI3.assert_called_once_with(
             drvr._live_migration_uri('dest'),
             params=params, flags=0)
@@ -9492,14 +9505,15 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
         drvr._parse_migration_flags()
 
+        _bandwidth = libvirt_driver.MIN_MIGRATION_SPEED_BW
         instance = objects.Instance(**self.test_instance)
         drvr._live_migration_operation(self.context, instance, 'dest',
                                        True, migrate_data, guest,
-                                       device_names)
+                                       device_names, _bandwidth)
 
         params = {
             'migrate_disks': device_names,
-            'bandwidth': CONF.libvirt.live_migration_bandwidth,
+            'bandwidth': _bandwidth,
             'destination_xml': '<xml/>',
         }
         mock_migrateToURI3.assert_called_once_with(
@@ -9538,8 +9552,9 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         self.flags(live_migration_tunnelled=True, group='libvirt')
         # Preparing mocks
         disk_paths = []
+        _bandwidth = libvirt_driver.MIN_MIGRATION_SPEED_BW
         params = {
-            'bandwidth': CONF.libvirt.live_migration_bandwidth,
+            'bandwidth': _bandwidth,
             'destination_xml': '',
         }
         # Start test
@@ -9558,7 +9573,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         drvr._parse_migration_flags()
         instance = objects.Instance(**self.test_instance)
         drvr._live_migration_operation(self.context, instance, 'dest',
-                          True, migrate_data, guest, disk_paths)
+                                       True, migrate_data, guest, disk_paths,
+                                       _bandwidth)
         expected_flags = (fakelibvirt.VIR_MIGRATE_UNDEFINE_SOURCE |
                           fakelibvirt.VIR_MIGRATE_PERSIST_DEST |
                           fakelibvirt.VIR_MIGRATE_TUNNELLED |
@@ -9584,7 +9600,7 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         vdmock = self.mox.CreateMock(fakelibvirt.virDomain)
         guest = libvirt_guest.Guest(vdmock)
         self.mox.StubOutWithMock(vdmock, "migrateToURI2")
-        _bandwidth = CONF.libvirt.live_migration_bandwidth
+        _bandwidth = libvirt_driver.MIN_MIGRATION_SPEED_BW
         vdmock.XMLDesc(flags=fakelibvirt.VIR_DOMAIN_XML_MIGRATABLE
         ).AndReturn(FakeVirtDomain().XMLDesc(flags=0))
         vdmock.migrateToURI2(drvr._live_migration_uri('dest'),
@@ -9606,7 +9622,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         self.assertRaises(fakelibvirt.libvirtError,
                           drvr._live_migration_operation,
                           self.context, instance_ref, 'dest',
-                          False, migrate_data, guest, [])
+                          False, migrate_data, guest, [],
+                          _bandwidth)
 
         self.assertEqual(vm_states.ACTIVE, instance_ref.vm_state)
         self.assertEqual(power_state.RUNNING, instance_ref.power_state)
@@ -10641,8 +10658,87 @@ class LibvirtConnTestCase(test.NoDBTestCase,
     def test_live_migration_main(self, mock_copy_disk_path, mock_running,
                                  mock_guest, mock_monitor, mock_thread,
                                  mock_conn):
+        virtapi = manager.ComputeVirtAPI(mock.MagicMock())
+        drvr = libvirt_driver.LibvirtDriver(virtapi, False)
+
+        instance = objects.Instance(**self.test_instance)
+        instance.info_cache = objects.InstanceInfoCache(
+            network_info=network_model.NetworkInfo([
+                network_model.VIF(id=uuids.vif_1,
+                                  type=network_model.VIF_TYPE_BRIDGE)]))
+
+        dom = fakelibvirt.Domain(drvr._get_connection(),
+                                 "<domain><name>demo</name></domain>", True)
+        guest = libvirt_guest.Guest(dom)
+        migrate_data = objects.LibvirtLiveMigrateData(block_migration=True)
+        disks_to_copy = (['/some/path/one', '/test/path/two'],
+                         ['vda', 'vdb'])
+        mock_copy_disk_path.return_value = disks_to_copy
+
+        mock_guest.return_value = guest
+        guest.migrate_configure_max_speed = mock.MagicMock()
+
+        generated_events = []
+
+        def fake_post():
+            pass
+
+        def fake_recover():
+            pass
+
+        def fake_prepare(instance, event_name):
+            ev = mock.MagicMock(instance=instance, event_name=event_name)
+            ev.wait.return_value = mock.MagicMock(status='completed')
+            generated_events.append(ev)
+            return ev
+
+        prepare = virtapi._compute.instance_events.prepare_for_instance_event
+        prepare.side_effect = fake_prepare
+
+        drvr._live_migration(self.context, instance, "fakehost",
+                             fake_post, fake_recover, True,
+                             migrate_data)
+        mock_copy_disk_path.assert_called_once_with(self.context, instance,
+                                                    guest)
+
+        class AnyEventletEvent(object):
+            def __eq__(self, other):
+                return type(other) == eventlet.event.Event
+
+        mock_thread.assert_called_once_with(
+            drvr._live_migration_operation,
+            self.context, instance, "fakehost", True,
+            migrate_data, guest, disks_to_copy[1],
+            libvirt_driver.MIN_MIGRATION_SPEED_BW)
+        mock_monitor.assert_called_once_with(
+            self.context, instance, guest, "fakehost",
+            fake_post, fake_recover, True,
+            migrate_data, AnyEventletEvent(), disks_to_copy[0])
+        guest.migrate_configure_max_speed.assert_called_once_with(
+            CONF.libvirt.live_migration_bandwidth)
+
+        prepare.assert_has_calls([
+            mock.call(instance, 'network-vif-plugged-%s' % uuids.vif_1)])
+        for event in generated_events:
+            event.wait.assert_called_once_with()
+
+    @mock.patch.object(host.Host, "get_connection")
+    @mock.patch.object(utils, "spawn")
+    @mock.patch.object(libvirt_driver.LibvirtDriver, "_live_migration_monitor")
+    @mock.patch.object(host.Host, "get_guest")
+    @mock.patch.object(fakelibvirt.Connection, "_mark_running")
+    @mock.patch.object(libvirt_driver.LibvirtDriver,
+                       "_live_migration_copy_disk_paths")
+    def test_live_migration_ovs_vif(self, mock_copy_disk_path, mock_running,
+                                    mock_guest, mock_monitor, mock_thread,
+                                    mock_conn):
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
         instance = objects.Instance(**self.test_instance)
+        instance.info_cache = objects.InstanceInfoCache(
+            network_info=network_model.NetworkInfo([
+                network_model.VIF(id=uuids.vif_1,
+                                  type=network_model.VIF_TYPE_OVS)]))
+
         dom = fakelibvirt.Domain(drvr._get_connection(),
                                  "<domain><name>demo</name></domain>", True)
         guest = libvirt_guest.Guest(dom)
@@ -10652,6 +10748,7 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         mock_copy_disk_path.return_value = disks_to_copy
 
         mock_guest.return_value = guest
+        guest.migrate_configure_max_speed = mock.MagicMock()
 
         def fake_post():
             pass
@@ -10672,11 +10769,70 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         mock_thread.assert_called_once_with(
             drvr._live_migration_operation,
             self.context, instance, "fakehost", True,
-            migrate_data, guest, disks_to_copy[1])
+            migrate_data, guest, disks_to_copy[1],
+            CONF.libvirt.live_migration_bandwidth)
         mock_monitor.assert_called_once_with(
             self.context, instance, guest, "fakehost",
             fake_post, fake_recover, True,
             migrate_data, AnyEventletEvent(), disks_to_copy[0])
+        guest.migrate_configure_max_speed.assert_not_called()
+
+    @mock.patch.object(host.Host, "get_connection")
+    @mock.patch.object(utils, "spawn")
+    @mock.patch.object(libvirt_driver.LibvirtDriver, "_live_migration_monitor")
+    @mock.patch.object(host.Host, "get_guest")
+    @mock.patch.object(fakelibvirt.Connection, "_mark_running")
+    @mock.patch.object(libvirt_driver.LibvirtDriver,
+                       "_live_migration_copy_disk_paths")
+    def test_live_migration_bridge_no_events(self, mock_copy_disk_path,
+                                             mock_running, mock_guest,
+                                             mock_monitor, mock_thread,
+                                             mock_conn):
+        self.flags(vif_plugging_timeout=0)
+        drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
+        instance = objects.Instance(**self.test_instance)
+        instance.info_cache = objects.InstanceInfoCache(
+            network_info=network_model.NetworkInfo([
+                network_model.VIF(id=uuids.vif_1,
+                                  type=network_model.VIF_TYPE_BRIDGE)]))
+
+        dom = fakelibvirt.Domain(drvr._get_connection(),
+                                 "<domain><name>demo</name></domain>", True)
+        guest = libvirt_guest.Guest(dom)
+        migrate_data = objects.LibvirtLiveMigrateData(block_migration=True)
+        disks_to_copy = (['/some/path/one', '/test/path/two'],
+                         ['vda', 'vdb'])
+        mock_copy_disk_path.return_value = disks_to_copy
+
+        mock_guest.return_value = guest
+        guest.migrate_configure_max_speed = mock.MagicMock()
+
+        def fake_post():
+            pass
+
+        def fake_recover():
+            pass
+
+        drvr._live_migration(self.context, instance, "fakehost",
+                             fake_post, fake_recover, True,
+                             migrate_data)
+        mock_copy_disk_path.assert_called_once_with(self.context, instance,
+                                                    guest)
+
+        class AnyEventletEvent(object):
+            def __eq__(self, other):
+                return type(other) == eventlet.event.Event
+
+        mock_thread.assert_called_once_with(
+            drvr._live_migration_operation,
+            self.context, instance, "fakehost", True,
+            migrate_data, guest, disks_to_copy[1],
+            CONF.libvirt.live_migration_bandwidth)
+        mock_monitor.assert_called_once_with(
+            self.context, instance, guest, "fakehost",
+            fake_post, fake_recover, True,
+            migrate_data, AnyEventletEvent(), disks_to_copy[0])
+        guest.migrate_configure_max_speed.assert_not_called()
 
     def _do_test_create_images_and_backing(self, disk_type):
         instance = objects.Instance(**self.test_instance)
@@ -15761,8 +15917,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
 
         instance = objects.Instance(vm_state=vm_states.BUILDING,
                                     **self.test_instance)
-        vifs = [{'id': 'vif1', 'active': False},
-                {'id': 'vif2', 'active': False}]
+        vifs = [{'id': uuids.vif_1, 'active': False},
+                {'id': uuids.vif_2, 'active': False}]
 
         @mock.patch.object(drvr, 'plug_vifs')
         @mock.patch.object(drvr, 'firewall_driver')
@@ -15788,8 +15944,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
 
         if utils.is_neutron() and CONF.vif_plugging_timeout and power_on:
             prepare.assert_has_calls([
-                mock.call(instance, 'network-vif-plugged-vif1'),
-                mock.call(instance, 'network-vif-plugged-vif2')])
+                mock.call(instance, 'network-vif-plugged-%s' % uuids.vif_1),
+                mock.call(instance, 'network-vif-plugged-%s' % uuids.vif_2)])
             for event in generated_events:
                 if neutron_failure and generated_events.index(event) != 0:
                     self.assertEqual(0, event.call_count)
@@ -16028,6 +16184,15 @@ class LibvirtConnTestCase(test.NoDBTestCase,
                 {'bus': 'virtio', 'type': 'disk', 'dev': 'vdc'})
             volume_save.assert_called_once_with()
 
+    def test_get_neutron_events_for_live_migration(self):
+        drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
+        network_info = [network_model.VIF(id=uuids.vif_ovs,
+                                          type=network_model.VIF_TYPE_OVS),
+                        network_model.VIF(id=uuids.vif_bridge,
+                                          type=network_model.VIF_TYPE_BRIDGE)]
+        events = drvr._get_neutron_events_for_live_migration(network_info)
+        self.assertEqual([('network-vif-plugged', uuids.vif_bridge)], events)
+
     def test_get_neutron_events(self):
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
         network_info = [network_model.VIF(id='1'),
diff --git a/nova/tests/unit/virt/test_virt_drivers.py b/nova/tests/unit/virt/test_virt_drivers.py
index c256bec29a..7823291df2 100644
--- a/nova/tests/unit/virt/test_virt_drivers.py
+++ b/nova/tests/unit/virt/test_virt_drivers.py
@@ -654,6 +654,8 @@ class _VirtDriverTestCase(_FakeDriverBackendTestCase):
 
     def test_live_migration(self):
         instance_ref, network_info = self._get_running_instance()
+        instance_ref.info_cache = objects.InstanceInfoCache(
+            network_info=network_info)
         fake_context = context.RequestContext('fake', 'fake')
         migration = objects.Migration(context=fake_context, id=1)
         migrate_data = objects.LibvirtLiveMigrateData(
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 5f23f08b9a..ed7915a1fa 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -321,6 +321,8 @@ MIN_QEMU_LUKS_VERSION = (2, 6, 0)
 
 VGPU_RESOURCE_SEMAPHORE = "vgpu_resources"
 
+MIN_MIGRATION_SPEED_BW = 1  # 1 MiB/s
+
 
 class LibvirtDriver(driver.ComputeDriver):
     capabilities = {
@@ -5516,6 +5518,12 @@ class LibvirtDriver(driver.ComputeDriver):
         if CONF.vif_plugging_is_fatal:
             raise exception.VirtualInterfaceCreateException()
 
+    def _neutron_failed_live_migration_callback(self, event_name, instance):
+        msg = ('Neutron reported failure during live migration '
+               'with %(event)s for instance %(uuid)s' %
+               {'event': event_name, 'uuid': instance.uuid})
+        raise exception.MigrationError(reason=msg)
+
     def _get_neutron_events(self, network_info):
         # NOTE(danms): We need to collect any VIFs that are currently
         # down that we expect a down->up event for. Anything that is
@@ -5525,6 +5533,16 @@ class LibvirtDriver(driver.ComputeDriver):
         return [('network-vif-plugged', vif['id'])
                 for vif in network_info if vif.get('active', True) is False]
 
+    def _get_neutron_events_for_live_migration(self, network_info):
+        # Neutron should send events to Nova indicating that the VIFs
+        # are successfully plugged on destination host.
+
+        # TODO(sahid): Currently we only use the mechanism of waiting
+        # for neutron events during live-migration for linux-bridge.
+        return [('network-vif-plugged', vif['id'])
+                for vif in network_info if (
+                        vif.get('type') == network_model.VIF_TYPE_BRIDGE)]
+
     def _cleanup_failed_start(self, context, instance, network_info,
                               block_device_info, guest, destroy_disks):
         try:
@@ -6894,7 +6912,7 @@ class LibvirtDriver(driver.ComputeDriver):
 
     def _live_migration_operation(self, context, instance, dest,
                                   block_migration, migrate_data, guest,
-                                  device_names):
+                                  device_names, bandwidth):
         """Invoke the live migration operation
 
         :param context: security context
@@ -6907,6 +6925,7 @@ class LibvirtDriver(driver.ComputeDriver):
         :param guest: the guest domain object
         :param device_names: list of device names that are being migrated with
             instance
+        :param bandwidth: MiB/s of bandwidth allowed for the migration at start
 
         This method is intended to be run in a background thread and will
         block that thread until the migration is finished or failed.
@@ -6980,7 +6999,7 @@ class LibvirtDriver(driver.ComputeDriver):
                           flags=migration_flags,
                           params=params,
                           domain_xml=new_xml_str,
-                          bandwidth=CONF.libvirt.live_migration_bandwidth)
+                          bandwidth=bandwidth)
 
             for hostname, port in serial_ports:
                 serial_console.release_port(host=hostname, port=port)
@@ -7323,11 +7342,58 @@ class LibvirtDriver(driver.ComputeDriver):
             disk_paths, device_names = self._live_migration_copy_disk_paths(
                 context, instance, guest)
 
-        opthread = utils.spawn(self._live_migration_operation,
-                                     context, instance, dest,
-                                     block_migration,
-                                     migrate_data, guest,
-                                     device_names)
+        deadline = CONF.vif_plugging_timeout
+        if utils.is_neutron() and deadline:
+            # We don't generate events if CONF.vif_plugging_timeout=0
+            # meaning that the operator disabled using them.
+
+            # In case of Linux Bridge, the agent is waiting for new
+            # TAP devices on destination node. They are going to be
+            # created by libvirt at the very beginning of the
+            # live-migration process. Then receiving the events from
+            # Neutron will ensure that everything is configured
+            # correctly.
+            events = self._get_neutron_events_for_live_migration(
+                instance.get_network_info())
+        else:
+            # TODO(sahid): This 'is_neutron()' condition should be
+            # removed when nova-network will be erased from the tree
+            # (Rocky).
+            events = []
+
+        if events:
+            # We start migration with the minimum bandwidth
+            # speed. Depending on the VIF type (see:
+            # _get_neutron_events_for_live_migration) we will wait for
+            # Neutron to send events that confirm network is setup or
+            # directly configure QEMU to use the maximun BW allowed.
+            bandwidth = MIN_MIGRATION_SPEED_BW
+        else:
+            bandwidth = CONF.libvirt.live_migration_bandwidth
+
+        try:
+            error_cb = self._neutron_failed_live_migration_callback
+            with self.virtapi.wait_for_instance_event(instance, events,
+                                                      deadline=deadline,
+                                                      error_callback=error_cb):
+                opthread = utils.spawn(self._live_migration_operation,
+                                       context, instance, dest,
+                                       block_migration,
+                                       migrate_data, guest,
+                                       device_names, bandwidth)
+        except eventlet.timeout.Timeout:
+            msg = ('Timeout waiting for VIF plugging events, '
+                   'canceling migration')
+            raise exception.MigrationError(reason=msg)
+        else:
+            if utils.is_neutron() and events:
+                LOG.debug('VIF events received, continuing migration '
+                          'with max bandwidth configured: %d',
+                          CONF.libvirt.live_migration_bandwidth,
+                          instance=instance)
+                # Configure QEMU to use the maximum bandwidth allowed.
+                guest.migrate_configure_max_speed(
+                    CONF.libvirt.live_migration_bandwidth)
 
         finish_event = eventlet.event.Event()
         self.active_migrations[instance.uuid] = deque()