This branch is a patch for fixing below issue.

> Bug #746821: live_migration failing due to network filter not found  Link a bug report

nova/tests/test_virt.py

@@ -479,7 +479,7 @@ class LibvirtConnTestCase(test.TestCase):
 
         fake_timer = FakeTime()
 
-        self.create_fake_libvirt_mock(nwfilterLookupByName=fake_raise)
+        self.create_fake_libvirt_mock()
         instance_ref = db.instance_create(self.context, self.test_instance)
 
         # Start test
@@ -488,6 +488,7 @@ class LibvirtConnTestCase(test.TestCase):
             conn = libvirt_conn.LibvirtConnection(False)
             conn.firewall_driver.setattr('setup_basic_filtering', fake_none)
             conn.firewall_driver.setattr('prepare_instance_filter', fake_none)
+            conn.firewall_driver.setattr('instance_filter_exists', fake_none)
             conn.ensure_filtering_rules_for_instance(instance_ref,
                                                      time=fake_timer)
         except exception.Error, e:

nova/virt/libvirt_conn.py

@@ -1404,18 +1404,13 @@ class LibvirtConnection(driver.ComputeDriver):
         # wait for completion
         timeout_count = range(FLAGS.live_migration_retry_count)
         while timeout_count:
-            try:
-                filter_name = 'nova-instance-%s' % instance_ref.name
-                self._conn.nwfilterLookupByName(filter_name)
+            if self.firewall_driver.instance_filter_exists(instance_ref):
                 break
-            except libvirt.libvirtError:
-                timeout_count.pop()
-                if len(timeout_count) == 0:
-                    ec2_id = instance_ref['hostname']
-                    iname = instance_ref.name
-                    msg = _('Timeout migrating for %(ec2_id)s(%(iname)s)')
-                    raise exception.Error(msg % locals())
-                time.sleep(1)
+            timeout_count.pop()
+            if len(timeout_count) == 0:
+                msg = _('Timeout migrating for %s. nwfilter not found.')
+                raise exception.Error(msg % instance_ref.name)
+            time.sleep(1)
 
     def live_migration(self, ctxt, instance_ref, dest,
                        post_method, recover_method):
@@ -1544,6 +1539,10 @@ class FirewallDriver(object):
         """
         raise NotImplementedError()
 
+    def instance_filter_exists(self, instance):
+        """Check nova-instance-instance-xxx exists"""
+        raise NotImplementedError()
+
 
 class NWFilterFirewall(FirewallDriver):
     """
@@ -1851,6 +1850,21 @@ class NWFilterFirewall(FirewallDriver):
             return 'nova-instance-%s' % (instance['name'])
         return 'nova-instance-%s-%s' % (instance['name'], nic_id)
 
+    def instance_filter_exists(self, instance):
+        """Check nova-instance-instance-xxx exists"""
+        network_info = _get_network_info(instance)
+        for (network, mapping) in network_info:
+            nic_id = mapping['mac'].replace(':', '')
+            instance_filter_name = self._instance_filter_name(instance, nic_id)
+            try:
+                self._conn.nwfilterLookupByName(instance_filter_name)
+            except libvirt.libvirtError:
+                name = instance.name
+                LOG.debug(_('The nwfilter(%(instance_filter_name)s) for'
+                            '%(name)s is not found.') % locals())
+                return False
+        return True
+
 
 class IptablesFirewallDriver(FirewallDriver):
     def __init__(self, execute=None, **kwargs):
@@ -2040,6 +2054,10 @@ class IptablesFirewallDriver(FirewallDriver):
 
         return ipv4_rules, ipv6_rules
 
+    def instance_filter_exists(self, instance):
+        """Check nova-instance-instance-xxx exists"""
+        return self.nwfilter.instance_filter_exists(instance)
+
     def refresh_security_group_members(self, security_group):
         pass