T6944: adds option to enable switchdev mode on ethernet interface

interface-definitions/interfaces_ethernet.xml.in

@@ -56,6 +56,12 @@
             </properties>
             <defaultValue>auto</defaultValue>
           </leafNode>
+          <leafNode name="switchdev">
+            <properties>
+              <help>Enables switchdev mode on interface</help>
+              <valueless/>
+            </properties>
+          </leafNode>
           #include <include/interface/eapol.xml.i>
           <node name="evpn">
             <properties>

python/vyos/ifconfig/ethernet.py

@@ -14,6 +14,7 @@
 # License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
+import re
 
 from glob import glob
 
@@ -417,12 +418,38 @@ def set_ring_buffer(self, rx_tx, size):
             print(f'could not set "{rx_tx}" ring-buffer for {ifname}')
         return output
 
+    def set_switchdev(self, enable):
+        ifname = self.config['ifname']
+        if not bool(re.match(r"^eth[0-9]+$", ifname)):
+            print(f'switchdev mode is only possible on physical interfaces!')
+            return
+
+        addr, code = self._popen(f'ethtool -i {ifname} | grep bus-info | awk \'{{print $2}}\'')
+        if code != 0:
+            print(f'could not resolve PCIe address of {ifname}')
+            return
+
+        enabled = False
+        state, code = self._popen(f'devlink dev eswitch show pci/0000:01:00.1  | awk \'{{print $3}}\'')
+        if code == 0 and state == 'switchdev':
+            enabled = True
+
+        if enable and not enabled:
+            output, code = self._popen(f'/sbin/devlink dev eswitch set pci/{addr} mode switchdev')
+            if code != 0:
+                raise ConfigError(f'{ifname} does not support switchdev mode')
+        elif not enable and enabled:
+            self._cmd(f'/sbin/devlink dev eswitch set pci/{addr} mode legacy')
+
     def update(self, config):
         """ General helper function which works on a dictionary retrived by
         get_config_dict(). It's main intention is to consolidate the scattered
         interface setup code and provide a single point of entry when workin
         on any interface. """
 
+        # enable switchdev mode for additional offload options
+        self.set_switchdev('switchdev' in config)
+
         # disable ethernet flow control (pause frames)
         value = 'off' if 'disable_flow_control' in config else 'on'
         self.set_flow_control(value)

smoketest/scripts/cli/test_interfaces_ethernet.py

@@ -222,5 +222,15 @@ def test_ethtool_evpn_uplink_tarcking(self):
             frrconfig = self.getFRRconfig(f'interface {interface}', daemon='zebra')
             self.assertIn(f' evpn mh uplink', frrconfig)
 
+    def test_switchdev(self):
+        interface = self._interfaces[0]
+        self.cli_set(self._base_path + [interface, 'switchdev'])
+
+        # check validate() - virtual interfaces do not support switchdev
+        with self.assertRaises(ConfigSessionError):
+            self.cli_commit()
+
+        self.cli_delete(self._base_path + [interface, 'switchdev'])
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)