Merge "libvirt: fix wrong driver name for vhostuser interface"

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

@@ -1933,6 +1933,32 @@ class LibvirtConfigGuestInterfaceTest(LibvirtConfigBaseTest):
         obj2.parse_str(xml)
         self.assertXmlEqual(xml, obj2.to_xml())
 
+    def test_config_vhostuser_ensure_driver_never_set(self):
+        obj = config.LibvirtConfigGuestInterface()
+        # Even if 'driver_name' attribute is set we should never set
+        # it in the domain XML for vhostuser interface.
+        obj.driver_name = "vhost-user"
+
+        obj.net_type = "vhostuser"
+        obj.vhostuser_type = "unix"
+        obj.vhostuser_mode = "server"
+        obj.mac_addr = "DE:AD:BE:EF:CA:FE"
+        obj.vhostuser_path = "/vhost-user/test.sock"
+        obj.model = "virtio"
+        xml = obj.to_xml()
+        self.assertXmlEqual(xml, """
+            <interface type="vhostuser">
+              <mac address="DE:AD:BE:EF:CA:FE"/>
+              <model type="virtio"/>
+              <source type="unix" mode="server" path="/vhost-user/test.sock"/>
+            </interface>""")
+
+        # parse the xml from the first object into a new object and make sure
+        # they are the same
+        obj2 = config.LibvirtConfigGuestInterface()
+        obj2.parse_str(xml)
+        self.assertXmlEqual(xml, obj2.to_xml())
+
     def test_config_interface_address(self):
         xml = """
             <interface type='network'>

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

@@ -672,7 +672,7 @@ class LibvirtVifTestCase(test.NoDBTestCase):
         d._set_config_VIFVHostUser(self.instance, self.os_vif_vhostuser,
                                    conf, hostimpl)
         self.assertEqual(4, conf.vhost_queues)
-        self.assertEqual('vhost', conf.driver_name)
+        self.assertIsNone(conf.driver_name)
         has_min_version.assert_called_once_with(MIN_LIBVIRT_VHOSTUSER_MQ)
 
         has_min_version.return_value = False

nova/virt/libvirt/config.py

@@ -1339,11 +1339,21 @@ class LibvirtConfigGuestInterface(LibvirtConfigGuestDevice):
         if self.model:
             dev.append(etree.Element("model", type=self.model))
 
+        drv_elem = None
         if self.driver_name:
             drv_elem = etree.Element("driver", name=self.driver_name)
+        if self.net_type == "vhostuser":
+            # For vhostuser interface we should not set the driver
+            # name.
+            drv_elem = etree.Element("driver")
+        if drv_elem is not None:
             if self.vhost_queues is not None:
                 drv_elem.set('queues', str(self.vhost_queues))
-            dev.append(drv_elem)
+
+            if drv_elem.get('name') or drv_elem.get('queues'):
+                # Append the driver element into the dom only if name
+                # or queues attributes are set.
+                dev.append(drv_elem)
 
         if self.net_type == "ethernet":
             if self.script is not None:

nova/virt/libvirt/vif.py

@@ -431,13 +431,18 @@ class LibvirtGenericVIFDriver(object):
         conf = self.get_base_config(instance, vif['address'], image_meta,
                                     inst_type, virt_type, vif['vnic_type'],
                                     host)
+        # TODO(sahid): We should never configure a driver backend for
+        # vhostuser interface. Specifically override driver to use
+        # None. This can be removed when get_base_config will be fixed
+        # and rewrite to set the correct backend.
+        conf.driver_name = None
+
         mode, sock_path = self._get_vhostuser_settings(vif)
         designer.set_vif_host_backend_vhostuser_config(conf, mode, sock_path)
         # (vladikr) Not setting up driver and queues for vhostuser
         # as queues are not supported in Libvirt until version 1.2.17
         if not host.has_min_version(MIN_LIBVIRT_VHOSTUSER_MQ):
             LOG.debug('Queues are not a vhostuser supported feature.')
-            conf.driver_name = None
             conf.vhost_queues = None
 
         return conf
@@ -474,11 +479,16 @@ class LibvirtGenericVIFDriver(object):
         self._set_config_VIFPortProfile(instance, vif, conf)
 
     def _set_config_VIFVHostUser(self, instance, vif, conf, host=None):
+        # TODO(sahid): We should never configure a driver backend for
+        # vhostuser interface. Specifically override driver to use
+        # None. This can be removed when get_base_config will be fixed
+        # and rewrite to set the correct backend.
+        conf.driver_name = None
+
         designer.set_vif_host_backend_vhostuser_config(
             conf, vif.mode, vif.path)
         if not host.has_min_version(MIN_LIBVIRT_VHOSTUSER_MQ):
             LOG.debug('Queues are not a vhostuser supported feature.')
-            conf.driver_name = None
             conf.vhost_queues = None
 
     def _set_config_VIFHostDevice(self, instance, vif, conf, host=None):