macvtap: ML2 mech driver for macvtap network attachments

This driver uses the vif_type 'macvtap'. It enriches the vif_details
with the corresponding attributes required by nova [1] to support
macvtap attachments for libvirt qemu/kvm guests.

The review is submitted in three parts:
 - Part 1
    Common functions that are used by the ml2 driver and the agent
 - Part 2 (this part)
     The Mechanism Driver to support port binding for macvtap attachments
 - Part 3
    The Macvtap L2 Agent.

[1] https://review.openstack.org/#/c/182283

Change-Id: I206f58a21c36e55de957d8a23993aa9bc26d1595
Partial-Bug: #1480979

neutron/extensions/portbindings.py

@@ -46,6 +46,9 @@ PROFILE = 'binding:profile'
 CAP_PORT_FILTER = 'port_filter'
 OVS_HYBRID_PLUG = 'ovs_hybrid_plug'
 VIF_DETAILS_VLAN = 'vlan'
+VIF_DETAILS_MACVTAP_SOURCE = 'macvtap_source'
+VIF_DETAILS_MACVTAP_MODE = 'macvtap_mode'
+VIF_DETAILS_PHYSICAL_INTERFACE = 'physical_interface'
 
 # The keys below are used in the VIF_DETAILS attribute to convey
 # information related to the configuration of the vhost-user VIF driver.
@@ -63,6 +66,10 @@ VHOST_USER_SOCKET = 'vhostuser_socket'
 #                        method should be used when binding the
 #                        vhost-user vif.
 VHOST_USER_OVS_PLUG = 'vhostuser_ovs_plug'
+
+# VIF_TYPE: vif_types are required by Nova to determine which vif_driver to
+#           use to attach a virtual server to the network
+
 # - vhost-user:  The vhost-user interface type is a standard virtio interface
 #                provided by qemu 2.1+. This constant defines the neutron side
 #                of the vif binding type to provide a common definition
@@ -75,7 +82,15 @@ VIF_TYPE_DISTRIBUTED = 'distributed'
 VIF_TYPE_OVS = 'ovs'
 VIF_TYPE_BRIDGE = 'bridge'
 VIF_TYPE_OTHER = 'other'
+# vif_type_macvtap: Tells Nova that the macvtap vif_driver should be used to
+#                   create a vif. It does not require the VNIC_TYPE_MACVTAP,
+#                   which is defined further below. E.g. Macvtap agent uses
+#                   vnic_type 'normal'.
+VIF_TYPE_MACVTAP = 'macvtap'
 
+# VNIC_TYPE: It's used to determine which mechanism driver to use to bind a
+#            port. It can be specified via the Neutron API. Default is normal,
+#            used by OVS and LinuxBridge agent.
 VNIC_NORMAL = 'normal'
 VNIC_DIRECT = 'direct'
 VNIC_MACVTAP = 'macvtap'

neutron/plugins/ml2/drivers/macvtap/mech_driver/mech_macvtap.py

@@ -0,0 +1,80 @@
+# Copyright (c) 2016 IBM Corp.
+#
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from oslo_log import log
+
+from neutron.common import constants
+from neutron.extensions import portbindings
+from neutron.plugins.common import constants as p_constants
+from neutron.plugins.ml2 import driver_api as api
+from neutron.plugins.ml2.drivers.macvtap import macvtap_common
+from neutron.plugins.ml2.drivers import mech_agent
+
+LOG = log.getLogger(__name__)
+
+MACVTAP_MODE_BRIDGE = 'bridge'
+
+
+class MacvtapMechanismDriver(mech_agent.SimpleAgentMechanismDriverBase):
+    """Attach to networks using Macvtap L2 agent.
+
+    The MacvtapMechanismDriver integrates the ml2 plugin with the
+    macvtap L2 agent. Port binding with this driver requires the
+    macvtap agent to be running on the port's host, and that agent
+    to have connectivity to at least one segment of the port's
+    network.
+    """
+
+    def __init__(self):
+        super(MacvtapMechanismDriver, self).__init__(
+            constants.AGENT_TYPE_MACVTAP,
+            portbindings.VIF_TYPE_MACVTAP,
+            {portbindings.CAP_PORT_FILTER: False})
+
+    def get_allowed_network_types(self, agent):
+        return [p_constants.TYPE_FLAT, p_constants.TYPE_VLAN]
+
+    def get_mappings(self, agent):
+        return agent['configurations'].get('interface_mappings', {})
+
+    def check_vlan_transparency(self, context):
+        """Macvtap driver vlan transparency support."""
+        return False
+
+    def try_to_bind_segment_for_agent(self, context, segment, agent):
+        if self.check_segment_for_agent(segment, agent):
+            vif_details_segment = self.vif_details
+            mappings = self.get_mappings(agent)
+            interface = mappings[segment['physical_network']]
+            network_type = segment[api.NETWORK_TYPE]
+
+            if network_type == p_constants.TYPE_VLAN:
+                vlan_id = segment[api.SEGMENTATION_ID]
+                macvtap_src = macvtap_common.get_vlan_device_name(interface,
+                                                                  vlan_id)
+                vif_details_segment['vlan'] = vlan_id
+            else:
+                macvtap_src = interface
+
+            vif_details_segment['physical_interface'] = interface
+            vif_details_segment['macvtap_source'] = macvtap_src
+            vif_details_segment['macvtap_mode'] = MACVTAP_MODE_BRIDGE
+            LOG.debug("Macvtap vif_details added to context binding: %s",
+                      vif_details_segment)
+            context.set_binding(segment[api.ID], self.vif_type,
+                                vif_details_segment)
+            return True
+        return False

neutron/tests/unit/plugins/ml2/drivers/macvtap/mech_driver/test_mech_macvtap.py

@@ -0,0 +1,92 @@
+# Copyright (c) 2015 IBM Corp.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from neutron.common import constants
+from neutron.extensions import portbindings
+from neutron.plugins.ml2.drivers.macvtap.mech_driver import mech_macvtap
+from neutron.tests.unit.plugins.ml2 import _test_mech_agent as base
+
+
+class MacvtapMechanismBaseTestCase(base.AgentMechanismBaseTestCase):
+    VIF_TYPE = portbindings.VIF_TYPE_MACVTAP
+    CAP_PORT_FILTER = False
+    AGENT_TYPE = constants.AGENT_TYPE_MACVTAP
+
+    GOOD_MAPPINGS = {'fake_physical_network': 'fake_if'}
+    GOOD_CONFIGS = {'interface_mappings': GOOD_MAPPINGS}
+
+    BAD_MAPPINGS = {'wrong_physical_network': 'wrong_if'}
+    BAD_CONFIGS = {'interface_mappings': BAD_MAPPINGS}
+
+    AGENTS = [{'alive': True,
+               'configurations': GOOD_CONFIGS,
+               'host': 'host'}]
+    AGENTS_DEAD = [{'alive': False,
+                    'configurations': GOOD_CONFIGS,
+                    'host': 'dead_host'}]
+    AGENTS_BAD = [{'alive': False,
+                   'configurations': GOOD_CONFIGS,
+                   'host': 'bad_host_1'},
+                  {'alive': True,
+                   'configurations': BAD_CONFIGS,
+                   'host': 'bad_host_2'}]
+
+    def setUp(self):
+        super(MacvtapMechanismBaseTestCase, self).setUp()
+        self.driver = mech_macvtap.MacvtapMechanismDriver()
+        self.driver.initialize()
+
+
+class MacvtapMechanismGenericTestCase(MacvtapMechanismBaseTestCase,
+                                      base.AgentMechanismGenericTestCase):
+    pass
+
+
+class MacvtapMechanismFlatTestCase(MacvtapMechanismBaseTestCase,
+                                   base.AgentMechanismFlatTestCase):
+    def test_type_flat_vif_details(self):
+        context = base.FakePortContext(self.AGENT_TYPE,
+                                  self.AGENTS,
+                                  self.FLAT_SEGMENTS,
+                                  vnic_type=self.VNIC_TYPE)
+        self.driver.bind_port(context)
+        vif_details = context._bound_vif_details
+
+        self.assertIsNone(vif_details.get(portbindings.VIF_DETAILS_VLAN))
+        self.assertEqual("bridge", vif_details.get(
+                                        portbindings.VIF_DETAILS_MACVTAP_MODE))
+        self.assertEqual("fake_if", vif_details.get(
+                                portbindings.VIF_DETAILS_PHYSICAL_INTERFACE))
+        self.assertEqual("fake_if", vif_details.get(
+                                    portbindings.VIF_DETAILS_MACVTAP_SOURCE))
+
+
+class MacvtapMechanismVlanTestCase(MacvtapMechanismBaseTestCase,
+                                   base.AgentMechanismVlanTestCase):
+    def test_type_vlan_vif_details(self):
+        context = base.FakePortContext(self.AGENT_TYPE,
+                                  self.AGENTS,
+                                  self.VLAN_SEGMENTS,
+                                  vnic_type=self.VNIC_TYPE)
+        self.driver.bind_port(context)
+        vif_details = context._bound_vif_details
+
+        self.assertEqual(1234, vif_details.get(portbindings.VIF_DETAILS_VLAN))
+        self.assertEqual("bridge", vif_details.get(
+                                       portbindings.VIF_DETAILS_MACVTAP_MODE))
+        self.assertEqual("fake_if", vif_details.get(
+                                portbindings.VIF_DETAILS_PHYSICAL_INTERFACE))
+        self.assertEqual("fake_if.1234", vif_details.get(
+                                     portbindings.VIF_DETAILS_MACVTAP_SOURCE))

setup.cfg

@@ -91,6 +91,7 @@ neutron.ml2.mechanism_drivers =
     logger = neutron.tests.unit.plugins.ml2.drivers.mechanism_logger:LoggerMechanismDriver
     test = neutron.tests.unit.plugins.ml2.drivers.mechanism_test:TestMechanismDriver
     linuxbridge = neutron.plugins.ml2.drivers.linuxbridge.mech_driver.mech_linuxbridge:LinuxbridgeMechanismDriver
+    macvtap = neutron.plugins.ml2.drivers.macvtap.mech_driver.mech_macvtap:MacvtapMechanismDriver
     openvswitch = neutron.plugins.ml2.drivers.openvswitch.mech_driver.mech_openvswitch:OpenvswitchMechanismDriver
     l2population = neutron.plugins.ml2.drivers.l2pop.mech_driver:L2populationMechanismDriver
     sriovnicswitch = neutron.plugins.ml2.drivers.mech_sriov.mech_driver.mech_driver:SriovNicSwitchMechanismDriver