Add support for direct ports with QoS in OVS

Today OVS mechanism driver can bind Direct port see [1] for OVS hardware
offloads.
OVS was extended with tc-offload to support rate limit see [2].
The OVS QoS driver [3] is limited to work only with Normal Ports, so we
can't put QoS rules on direct port.
This patch proposes to add support in OVS QoS driver for direct ports.
The mechanism to enforce such policies is the same with normal and
hardware offloaded direct ports.

[1] - e7f6ba220e
[2] - 3b074128ca/neutron/plugins/ml2/drivers/openvswitch/mech_driver/mech_openvswitch.py (L83)
[3] - 3b074128ca/neutron/services/qos/drivers/openvswitch/driver.py (L56)

Change-Id: I24b5cd6c022e479080fc84e4c445c9cddfc88e38
Closes-Bug: #1843165

doc/source/contributor/internals/quality_of_service.rst

@@ -363,6 +363,11 @@ integration bridge functions:
 The DSCP markings are in fact configured on the port by means of
 openflow rules.
 
+.. note::
+ As of Ussuri release, the QoS rules can be applied for direct ports with hardware
+ offload capability (switchdev), this requires Open vSwitch version 2.11.0 or newer
+ and Linux kernel based on kernel 5.4.0 or newer.
+
 SR-IOV
 ++++++
 

neutron/cmd/sanity/checks.py

@@ -23,6 +23,7 @@ from neutron_lib import exceptions
 from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import uuidutils
+from oslo_utils import versionutils
 
 from neutron.agent.common import ovs_lib
 from neutron.agent.l3 import ha_router
@@ -42,6 +43,7 @@ LOG = logging.getLogger(__name__)
 
 MINIMUM_DNSMASQ_VERSION = 2.67
 DNSMASQ_VERSION_DHCP_RELEASE6 = 2.76
+DIRECT_PORT_QOS_MIN_OVS_VERSION = '2.11'
 MINIMUM_DIBBLER_VERSION = '1.0.1'
 CONNTRACK_GRE_MODULE = 'nf_conntrack_proto_gre'
 
@@ -199,6 +201,10 @@ def get_dnsmasq_version_with_dhcp_release6():
     return DNSMASQ_VERSION_DHCP_RELEASE6
 
 
+def get_ovs_version_for_qos_direct_port_support():
+    return DIRECT_PORT_QOS_MIN_OVS_VERSION
+
+
 def dnsmasq_local_service_supported():
     cmd = ['dnsmasq', '--test', '--local-service']
     env = {'LC_ALL': 'C'}
@@ -230,6 +236,26 @@ def dnsmasq_version_supported():
     return True
 
 
+def ovs_qos_direct_port_supported():
+    try:
+        cmd = ['ovs-vsctl', '-V']
+        out = agent_utils.execute(cmd)
+        matched_line = re.search(r"ovs-vsctl.*", out)
+        matched_version = re.search(r"(\d+\.\d+)", matched_line.group(0))
+        ver = versionutils.convert_version_to_tuple(matched_version.group(1) if
+                                                    matched_version else '0.0')
+        minver = versionutils.convert_version_to_tuple(
+                 DIRECT_PORT_QOS_MIN_OVS_VERSION)
+        if ver < minver:
+            return False
+    except (OSError, RuntimeError, ValueError) as e:
+        LOG.debug("Exception while checking minimal ovs version "
+                  "required for supporting direct ports QoS rules. "
+                  "Exception: %s", e)
+        return False
+    return True
+
+
 def dhcp_release6_supported():
     return runtime_checks.dhcp_release6_supported()
 

neutron/cmd/sanity_check.py

@@ -118,6 +118,16 @@ def check_dnsmasq_version():
     return result
 
 
+def check_ovs_qos_direct_ports_supported():
+    result = checks.ovs_qos_direct_port_supported()
+    if not result:
+        LOG.error('The installed version of OVS does not support '
+                  'QoS rules for direct ports. '
+                  'Please update to version %s or newer.',
+                  checks.get_ovs_version_for_qos_direct_port_support())
+    return result
+
+
 def check_dnsmasq_local_service_supported():
     result = checks.dnsmasq_local_service_supported()
     if not result:
@@ -324,6 +334,9 @@ OPTS = [
     BoolOptCallback('dnsmasq_local_service_supported',
                     check_dnsmasq_local_service_supported,
                     help=_('Check for local-service support in dnsmasq')),
+    BoolOptCallback('ovs_qos_direct_port_supported',
+                    check_ovs_qos_direct_ports_supported,
+                    help=_('Check if the ovs supports QoS for direct ports')),
     BoolOptCallback('dnsmasq_version', check_dnsmasq_version,
                     help=_('Check minimal dnsmasq version'),
                     deprecated_for_removal=True,

neutron/services/qos/drivers/openvswitch/driver.py

@@ -53,7 +53,7 @@ class OVSDriver(base.DriverBase):
             name='openvswitch',
             vif_types=[portbindings.VIF_TYPE_OVS,
                        portbindings.VIF_TYPE_VHOST_USER],
-            vnic_types=[portbindings.VNIC_NORMAL],
+            vnic_types=[portbindings.VNIC_NORMAL, portbindings.VNIC_DIRECT],
             supported_rules=SUPPORTED_RULES,
             requires_rpc_notifications=True)
 

releasenotes/notes/Add-support-for-direct-ports-with-QoS-in-OVS-48c78c156606e724.yaml

@@ -0,0 +1,7 @@
+---
+other:
+  - |
+    Added QoS support for direct ports in neutron.
+    The support requires Open vSwitch 2.11.0 or newer and is based on Linux kernel 5.4.0 or newer.
+    [`bug 1843165 <https://bugs.launchpad.net/neutron/+bug/1843165>`_].
+