diff --git a/nova/tests/unit/virt/libvirt/test_driver.py b/nova/tests/unit/virt/libvirt/test_driver.py
old mode 100644
new mode 100755
index a4454333afc2..db1a692801f1
--- a/nova/tests/unit/virt/libvirt/test_driver.py
+++ b/nova/tests/unit/virt/libvirt/test_driver.py
@@ -8275,6 +8275,61 @@ class LibvirtConnTestCase(test.NoDBTestCase):
             drvr._live_migration_uri('dest'),
             params=params, flags=0)
 
+    @mock.patch.object(fakelibvirt.virDomain, "migrateToURI3")
+    @mock.patch.object(host.Host, 'has_min_version', return_value=True)
+    @mock.patch('nova.virt.libvirt.guest.Guest.get_xml_desc',
+                return_value='<xml/>')
+    def _test_live_migration_block_migration_flags(self,
+            device_names, expected_flags,
+            mock_old_xml, mock_min_version, mock_migrateToURI3):
+        migrate_data = objects.LibvirtLiveMigrateData(
+            graphics_listen_addr_vnc='0.0.0.0',
+            graphics_listen_addr_spice='0.0.0.0',
+            serial_listen_addr='127.0.0.1',
+            target_connect_addr=None,
+            bdms=[],
+            block_migration=True)
+
+        dom = fakelibvirt.virDomain
+        guest = libvirt_guest.Guest(dom)
+        drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
+        drvr._parse_migration_flags()
+
+        instance = objects.Instance(**self.test_instance)
+        drvr._live_migration_operation(self.context, instance, 'dest',
+                                       True, migrate_data, guest,
+                                       device_names)
+
+        params = {
+            'migrate_disks': device_names,
+            'bandwidth': CONF.libvirt.live_migration_bandwidth,
+            'destination_xml': b'<xml/>',
+        }
+        mock_migrateToURI3.assert_called_once_with(
+            drvr._live_migration_uri('dest'), params=params,
+            flags=expected_flags)
+
+    def test_live_migration_block_migration_with_devices(self):
+        device_names = ['vda']
+        expected_flags = (fakelibvirt.VIR_MIGRATE_NON_SHARED_INC |
+                          fakelibvirt.VIR_MIGRATE_UNDEFINE_SOURCE |
+                          fakelibvirt.VIR_MIGRATE_PERSIST_DEST |
+                          fakelibvirt.VIR_MIGRATE_PEER2PEER |
+                          fakelibvirt.VIR_MIGRATE_LIVE)
+
+        self._test_live_migration_block_migration_flags(device_names,
+                                                        expected_flags)
+
+    def test_live_migration_block_migration_all_filtered(self):
+        device_names = []
+        expected_flags = (fakelibvirt.VIR_MIGRATE_UNDEFINE_SOURCE |
+                          fakelibvirt.VIR_MIGRATE_PERSIST_DEST |
+                          fakelibvirt.VIR_MIGRATE_PEER2PEER |
+                          fakelibvirt.VIR_MIGRATE_LIVE)
+
+        self._test_live_migration_block_migration_flags(device_names,
+                                                        expected_flags)
+
     @mock.patch.object(host.Host, 'has_min_version', return_value=True)
     @mock.patch.object(fakelibvirt.virDomain, "migrateToURI3")
     @mock.patch('nova.virt.libvirt.migration.get_updated_guest_xml',
@@ -8307,9 +8362,14 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         instance = objects.Instance(**self.test_instance)
         drvr._live_migration_operation(self.context, instance, 'dest',
                           True, migrate_data, guest, disk_paths)
+        expected_flags = (fakelibvirt.VIR_MIGRATE_UNDEFINE_SOURCE |
+                          fakelibvirt.VIR_MIGRATE_PERSIST_DEST |
+                          fakelibvirt.VIR_MIGRATE_TUNNELLED |
+                          fakelibvirt.VIR_MIGRATE_PEER2PEER |
+                          fakelibvirt.VIR_MIGRATE_LIVE)
         mock_migrateToURI3.assert_called_once_with(
             drvr._live_migration_uri('dest'),
-            params=params, flags=159)
+            params=params, flags=expected_flags)
 
     def test_live_migration_raises_exception(self):
         # Confirms recover method is called when exceptions are raised.
diff --git a/nova/virt/libvirt/guest.py b/nova/virt/libvirt/guest.py
old mode 100644
new mode 100755
index ee74d90ec708..457d73bdf135
--- a/nova/virt/libvirt/guest.py
+++ b/nova/virt/libvirt/guest.py
@@ -641,6 +641,18 @@ class Guest(object):
                 destination, flags=flags, bandwidth=bandwidth)
         else:
             if params:
+                # Due to a quirk in the libvirt python bindings,
+                # VIR_MIGRATE_NON_SHARED_INC with an empty migrate_disks is
+                # interpreted as "block migrate all writable disks" rather than
+                # "don't block migrate any disks". This includes attached
+                # volumes, which will potentially corrupt data on those
+                # volumes. Consequently we need to explicitly unset
+                # VIR_MIGRATE_NON_SHARED_INC if there are no disks to be block
+                # migrated.
+                if (flags & libvirt.VIR_MIGRATE_NON_SHARED_INC != 0 and
+                        not params.get('migrate_disks')):
+                    flags &= ~libvirt.VIR_MIGRATE_NON_SHARED_INC
+
                 # In migrateToURI3 these parameters are extracted from the
                 # `params` dict
                 if migrate_uri: