Revert MTU hacks for bug 1623876

Now with the native support for MTUs in the os-vif data model,
we no longer require the MTU hacks added at the end of Newton
to honor the MTUs set by Neutron.

Revert "Stop ovn networking failing on mtu"
This reverts commit fc0e281743.
Revert "Override MTU for os_vif attachments"
This reverts commit 77f546623b.

Related-Bug: #1623876
Change-Id: I82d7a1630e81254dfd6196d51add19ac2cbc5bdb

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

@@ -12,7 +12,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import copy
 import os
 
 import fixtures
@@ -1616,59 +1615,3 @@ class LibvirtVifTestCase(test.NoDBTestCase):
                 <filterref
                  filter="nova-instance-instance-00000001-22522562e2aa"/>
             </interface>""", cfg.to_xml())
-
-    @mock.patch('nova.network.linux_net._set_device_mtu')
-    @mock.patch("nova.network.os_vif_util.nova_to_osvif_instance")
-    @mock.patch("nova.network.os_vif_util.nova_to_osvif_vif")
-    @mock.patch.object(os_vif, "plug")
-    def test_plug_ovs_vif_no_mtu(self, mock_plug,
-                              mock_convert_vif, mock_convert_inst,
-                              mock_set_mtu):
-        mock_convert_vif.return_value = self.os_vif_bridge
-        mock_convert_inst.return_value = self.os_vif_inst_info
-
-        d = vif.LibvirtGenericVIFDriver()
-        # Hack the network mtu in the vif_bridge object - make sure to copy it
-        # so we don't change state on a global object during a test run.
-        vif_bridge = copy.deepcopy(self.vif_bridge)
-        vif_bridge['network']._set_meta({'mtu': None})
-        d.plug(self.instance, vif_bridge)
-
-        self.assertFalse(mock_set_mtu.called)
-
-    @mock.patch('nova.network.linux_net._set_device_mtu')
-    @mock.patch("nova.network.os_vif_util.nova_to_osvif_instance")
-    @mock.patch("nova.network.os_vif_util.nova_to_osvif_vif")
-    @mock.patch.object(os_vif, "plug")
-    def test_plug_ovs_vif_mtu(self, mock_plug,
-                              mock_convert_vif, mock_convert_inst,
-                              mock_set_mtu):
-        # Hack port profile to say ovs, just like ovn
-        os_vif_bridge = copy.deepcopy(self.os_vif_bridge)
-        os_vif_bridge.port_profile = self.os_vif_ovs_prof
-        mock_convert_vif.return_value = os_vif_bridge
-        mock_convert_inst.return_value = self.os_vif_inst_info
-
-        d = vif.LibvirtGenericVIFDriver()
-        d.plug(self.instance, self.vif_bridge)
-
-        self.assertEqual(3, mock_set_mtu.call_count)
-        mock_set_mtu.assert_any_call("br0", 9000)
-        mock_set_mtu.assert_any_call("qvbdc065497-3c", 9000)
-        mock_set_mtu.assert_any_call("qvodc065497-3c", 9000)
-
-    @mock.patch('nova.network.linux_net._set_device_mtu')
-    @mock.patch("nova.network.os_vif_util.nova_to_osvif_instance")
-    @mock.patch("nova.network.os_vif_util.nova_to_osvif_vif")
-    @mock.patch.object(os_vif, "plug")
-    def test_plug_ovs_vif_no_mtu_venv(self, mock_plug,
-                              mock_convert_vif, mock_convert_inst,
-                              mock_set_mtu):
-        mock_convert_vif.return_value = self.os_vif_ovs
-        mock_convert_inst.return_value = self.os_vif_inst_info
-
-        d = vif.LibvirtGenericVIFDriver()
-        d.plug(self.instance, self.vif_ovs)
-
-        self.assertEqual(1, mock_set_mtu.call_count)
-        mock_set_mtu.assert_any_call("br0", 1000)

nova/virt/libvirt/vif.py

@@ -775,7 +775,7 @@ class LibvirtGenericVIFDriver(object):
         except processutils.ProcessExecutionError:
             LOG.exception(_LE("Failed while plugging vif"), instance=instance)
 
-    def _plug_os_vif(self, instance, vif, raw_vif):
+    def _plug_os_vif(self, instance, vif):
         instance_info = os_vif_util.nova_to_osvif_instance(instance)
 
         try:
@@ -785,22 +785,6 @@ class LibvirtGenericVIFDriver(object):
                    % {'ex': ex})
             raise exception.NovaException(msg)
 
-        # TODO(johngarbutt) remove this hack once 1623876 is fixed in os-vif
-        network = raw_vif.get('network')
-        mtu = network.get_meta('mtu') if network else None
-        if mtu is not None:
-            linux_net._set_device_mtu(network["bridge"], mtu)
-
-        if (type(vif) == os_vif.objects.vif.VIFBridge and
-            hasattr(vif, "port_profile") and
-            isinstance(vif.port_profile,
-                       os_vif.objects.vif.VIFPortProfileOpenVSwitch)):
-            veths = [
-                ("qvb%s" % vif.id)[:network_model.NIC_NAME_LEN],
-                ("qvo%s" % vif.id)[:network_model.NIC_NAME_LEN]]
-            for veth in veths:
-                linux_net._set_device_mtu(veth, mtu)
-
     def plug(self, instance, vif):
         vif_type = vif['type']
 
@@ -817,7 +801,7 @@ class LibvirtGenericVIFDriver(object):
         # Try os-vif codepath first
         vif_obj = os_vif_util.nova_to_osvif_vif(vif)
         if vif_obj is not None:
-            self._plug_os_vif(instance, vif_obj, vif)
+            self._plug_os_vif(instance, vif_obj)
             return
 
         # Legacy non-os-vif codepath