Add support for VNIC type vDPA to ML2/OVS and ML2/OVN

This change adds VNIC type vDPA ("vdpa") to the list of
supported VNIC types for the OVS and OVN mech drivers.

Depends-On: https://review.opendev.org/#/c/760043/
Change-Id: If22aedc147f7e2256f8f8ad3bebb80b6bb2f6d3d

neutron/plugins/ml2/drivers/openvswitch/mech_driver/mech_openvswitch.py

@@ -75,7 +75,9 @@ class OpenvswitchMechanismDriver(mech_agent.SimpleAgentMechanismDriverBase):
         self.supported_vnic_types = self.prohibit_list_supported_vnic_types(
             vnic_types=[portbindings.VNIC_NORMAL,
                         portbindings.VNIC_DIRECT,
-                        portbindings.VNIC_SMARTNIC],
+                        portbindings.VNIC_SMARTNIC,
+                        portbindings.VNIC_VHOST_VDPA,
+                        ],
             prohibit_list=cfg.CONF.OVS_DRIVER.vnic_type_prohibit_list
         )
         LOG.info("%s's supported_vnic_types: %s",
@@ -121,6 +123,11 @@ class OpenvswitchMechanismDriver(mech_agent.SimpleAgentMechanismDriverBase):
         capabilities = []
         if profile:
             capabilities = profile.get('capabilities', [])
+        # TODO(sean-k-mooney): in the case of the Mellanox connectx6 dx and lx
+        # nics vhost-vdpa is only supported in switchdev mode but that is not
+        # strictly required by other vendors so we should ideally add a config
+        # value to control checking of switchdev support per host via the
+        # agent['configurations']
         if (vnic_type == portbindings.VNIC_DIRECT and
                 'switchdev' not in capabilities):
             LOG.debug("Refusing to bind due to unsupported vnic_type: %s with "

neutron/plugins/ml2/drivers/ovn/mech_driver/mech_driver.py

@@ -176,7 +176,9 @@ class OVNMechanismDriver(api.MechanismDriver):
         self.supported_vnic_types = [portbindings.VNIC_NORMAL,
                                      portbindings.VNIC_DIRECT,
                                      portbindings.VNIC_DIRECT_PHYSICAL,
-                                     portbindings.VNIC_MACVTAP]
+                                     portbindings.VNIC_MACVTAP,
+                                     portbindings.VNIC_VHOST_VDPA,
+                                     ]
         self.vif_details = {
             portbindings.VIF_TYPE_OVS: {
                 portbindings.CAP_PORT_FILTER: self.sg_enabled

neutron/tests/unit/plugins/ml2/drivers/openvswitch/mech_driver/test_mech_openvswitch.py

@@ -332,7 +332,9 @@ class OpenvswitchMechVnicTypesTestCase(OpenvswitchMechanismBaseTestCase):
 
     supported_vnics = [portbindings.VNIC_NORMAL,
                        portbindings.VNIC_DIRECT,
-                       portbindings.VNIC_SMARTNIC]
+                       portbindings.VNIC_SMARTNIC,
+                       portbindings.VNIC_VHOST_VDPA,
+                       ]
 
     def setUp(self):
         self.prohibit_list_cfg = {

neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py

@@ -1132,6 +1132,27 @@ class TestOVNMechanismDriver(test_plugin.Ml2PluginV2TestCase):
             portbindings.VIF_TYPE_OVS,
             self.mech_driver.vif_details[portbindings.VIF_TYPE_OVS])
 
+    def test_bind_port_vdpa(self):
+        segment_attrs = {'network_type': 'geneve',
+                         'physical_network': None,
+                         'segmentation_id': 1023}
+        fake_segments = \
+            [fakes.FakeSegment.create_one_segment(attrs=segment_attrs).info()]
+
+        fake_port = fakes.FakePort.create_one_port(
+            attrs={'binding:vnic_type': 'vdpa',
+                   'binding:profile': {'pci_slot': "0000:04:00.0"}}).info()
+        fake_host = 'host'
+        fake_port_context = fakes.FakePortContext(
+            fake_port, fake_host, fake_segments)
+        self.mech_driver.bind_port(fake_port_context)
+        self.sb_ovn.get_chassis_data_for_ml2_bind_port.assert_called_once_with(
+            fake_host)
+        fake_port_context.set_binding.assert_called_once_with(
+            fake_segments[0]['id'],
+            portbindings.VIF_TYPE_OVS,
+            self.mech_driver.vif_details[portbindings.VIF_TYPE_OVS])
+
     def test_bind_port_geneve(self):
         segment_attrs = {'network_type': 'geneve',
                          'physical_network': None,

releasenotes/notes/vhost-vdpa-4597a27de6232350.yaml

@@ -0,0 +1,14 @@
+---
+features:
+  - |
+    A new vnic type ``vdpa`` has been added to allow requesting port that
+    utilize a vHost-vDPA offload. The ML2/OVS and ML2/OVN mech drivers now
+    have support for the vHost-vDPA vnic type. vHost-vDPA is similar to
+    vHost-user or kernel vhost offload but utilizes the newly added vDPA bus
+    introduced in the Linux 5.7 kernel. vDPA interface can be implemented in
+    software or hardware, when implemented in hardware they provide equivalent
+    performance to SR-IOV or hardware offloaded OVS while providing two main
+    advantages over both SR-IOV and hardware offloaded OVS. Unlike the
+    alternatives, vHost-vDPA enables live migration of instance transparently
+    and provides a standard virtio-net interface to the guest avoiding the
+    need to install vendor specific drivers in the guest.