Merge "libvirt: add a new live_migration_tunnelled config"

nova/tests/unit/virt/libvirt/test_driver.py

@@ -1073,6 +1073,53 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         msg = mock_log.warning.call_args_list[3]
         self.assertIn('Removing the VIR_MIGRATE_PERSIST_DEST flag', msg[0][0])
 
+    @mock.patch('nova.virt.libvirt.driver.LOG')
+    def test_live_migration_tunnelled_true(self, mock_log):
+        self.flags(live_migration_tunnelled=True, group='libvirt')
+
+        self._do_test_parse_migration_flags(
+            lm_config=('VIR_MIGRATE_PEER2PEER, VIR_MIGRATE_UNDEFINE_SOURCE, '
+                       'VIR_MIGRATE_LIVE'),
+            bm_config=('VIR_MIGRATE_PEER2PEER, VIR_MIGRATE_UNDEFINE_SOURCE, '
+                       'VIR_MIGRATE_LIVE, VIR_MIGRATE_NON_SHARED_INC'),
+            lm_expected=(libvirt_driver.libvirt.VIR_MIGRATE_LIVE |
+                         libvirt_driver.libvirt.VIR_MIGRATE_PEER2PEER |
+                         libvirt_driver.libvirt.VIR_MIGRATE_UNDEFINE_SOURCE |
+                         libvirt_driver.libvirt.VIR_MIGRATE_TUNNELLED),
+            bm_expected=(libvirt_driver.libvirt.VIR_MIGRATE_LIVE |
+                         libvirt_driver.libvirt.VIR_MIGRATE_PEER2PEER |
+                         libvirt_driver.libvirt.VIR_MIGRATE_UNDEFINE_SOURCE |
+                         libvirt_driver.libvirt.VIR_MIGRATE_NON_SHARED_INC |
+                         libvirt_driver.libvirt.VIR_MIGRATE_TUNNELLED))
+
+        msg = mock_log.warning.call_args_list[0]
+        self.assertIn('does not contain the VIR_MIGRATE_TUNNELLED', msg[0][0])
+        msg = mock_log.warning.call_args_list[1]
+        self.assertIn('does not contain the VIR_MIGRATE_TUNNELLED', msg[0][0])
+
+    @mock.patch('nova.virt.libvirt.driver.LOG')
+    def test_live_migration_tunnelled_false(self, mock_log):
+        self.flags(live_migration_tunnelled=False, group='libvirt')
+
+        self._do_test_parse_migration_flags(
+            lm_config=('VIR_MIGRATE_PEER2PEER, VIR_MIGRATE_UNDEFINE_SOURCE, '
+                       'VIR_MIGRATE_LIVE, VIR_MIGRATE_TUNNELLED'),
+            bm_config=('VIR_MIGRATE_PEER2PEER, VIR_MIGRATE_UNDEFINE_SOURCE, '
+                       'VIR_MIGRATE_LIVE, VIR_MIGRATE_NON_SHARED_INC, '
+                       'VIR_MIGRATE_TUNNELLED'),
+            lm_expected=(libvirt_driver.libvirt.VIR_MIGRATE_LIVE |
+                         libvirt_driver.libvirt.VIR_MIGRATE_PEER2PEER |
+                         libvirt_driver.libvirt.VIR_MIGRATE_UNDEFINE_SOURCE),
+            bm_expected=(libvirt_driver.libvirt.VIR_MIGRATE_LIVE |
+                         libvirt_driver.libvirt.VIR_MIGRATE_PEER2PEER |
+                         libvirt_driver.libvirt.VIR_MIGRATE_UNDEFINE_SOURCE |
+                         libvirt_driver.libvirt.VIR_MIGRATE_NON_SHARED_INC))
+
+        msg = mock_log.warning.call_args_list[0]
+        self.assertIn('contains the VIR_MIGRATE_TUNNELLED flag', msg[0][0])
+        msg = mock_log.warning.call_args_list[1]
+        self.assertIn('contains the VIR_MIGRATE_TUNNELLED flag', msg[0][0])
+
     @mock.patch('nova.utils.get_image_from_system_metadata')
     @mock.patch.object(host.Host,
                        'has_min_version', return_value=True)

nova/virt/libvirt/driver.py

@@ -170,6 +170,16 @@ libvirt_opts = [
                        'VIR_MIGRATE_LIVE, VIR_MIGRATE_TUNNELLED, '
                        'VIR_MIGRATE_NON_SHARED_INC',
                help='Migration flags to be set for block migration'),
+    cfg.BoolOpt('live_migration_tunnelled',
+                help='Whether to use tunnelled migration, where migration '
+                     'data is transported over the libvirtd connection. If '
+                     'True, we use the VIR_MIGRATE_TUNNELLED migration flag, '
+                     'avoiding the need to configure the network to allow '
+                     'direct hypervisor to hypervisor communication. If '
+                     'False, use the native transport. If not set, Nova '
+                     'will choose a sensible default based on, for example '
+                     'the availability of native encryption support in the '
+                     'hypervisor.'),
     cfg.IntOpt('live_migration_bandwidth',
                default=0,
                help='Maximum bandwidth(in MiB/s) to be used during migration. '
@@ -721,6 +731,31 @@ class LibvirtDriver(driver.ComputeDriver):
 
         return (live_migration_flags, block_migration_flags)
 
+    def _handle_live_migration_tunnelled(self, migration_flags, config_name):
+        if CONF.libvirt.live_migration_tunnelled is None:
+            return migration_flags
+
+        if CONF.libvirt.live_migration_tunnelled:
+            if (migration_flags & libvirt.VIR_MIGRATE_TUNNELLED) == 0:
+                LOG.warning(_LW('The %(config_name)s config option does not '
+                                'contain the VIR_MIGRATE_TUNNELLED flag but '
+                                'the live_migration_tunnelled is set to True '
+                                'which causes VIR_MIGRATE_TUNNELLED to be '
+                                'set'),
+                            {'config_name': config_name})
+            migration_flags |= libvirt.VIR_MIGRATE_TUNNELLED
+        else:
+            if (migration_flags & libvirt.VIR_MIGRATE_TUNNELLED) != 0:
+                LOG.warning(_LW('The %(config_name)s config option contains '
+                                'the VIR_MIGRATE_TUNNELLED flag but the '
+                                'live_migration_tunnelled is set to False '
+                                'which causes VIR_MIGRATE_TUNNELLED to be '
+                                'unset'),
+                            {'config_name': config_name})
+            migration_flags &= ~libvirt.VIR_MIGRATE_TUNNELLED
+
+        return migration_flags
+
     def _parse_migration_flags(self):
         def str2sum(str_val):
             logical_sum = 0
@@ -747,6 +782,11 @@ class LibvirtDriver(driver.ComputeDriver):
          block_migration_flags) = self._check_block_migration_flags(
              live_migration_flags, block_migration_flags)
 
+        live_migration_flags = self._handle_live_migration_tunnelled(
+            live_migration_flags, live_config_name)
+        block_migration_flags = self._handle_live_migration_tunnelled(
+            block_migration_flags, block_config_name)
+
         self._live_migration_flags = live_migration_flags
         self._block_migration_flags = block_migration_flags
 

releasenotes/notes/libvirt-live-migration-new-tunneled-option-d7ebb1eb1e95e683.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - The libvirt driver now has a live_migration_tunnelled
+    configuration option which should be used where the
+    VIR_MIGRATE_TUNNELLED flag would previously have been
+    set or unset in the live_migration_flag and
+    block_migration_flag configuration options.