ethernet: T3171: add CLI option to enable RPS (Receive Packet Steering)

set interfaces ethernet <interface> offload rps

5 files changed, 74 insertions, 6 deletions

diff --git a/interface-definitions/interfaces-ethernet.xml.in b/interface-definitions/interfaces-ethernet.xml.in
index 4c4fae673..be44072a6 100644
--- a/interface-definitions/interfaces-ethernet.xml.in
+++ b/interface-definitions/interfaces-ethernet.xml.in
@@ -77,6 +77,12 @@
                   <valueless/>
                 </properties>
               </leafNode>
+              <leafNode name="rps">
+                <properties>
+                  <help>Enable Receive Packet Steering</help>
+                  <valueless/>
+                </properties>
+              </leafNode>
               <leafNode name="sg">
                 <properties>
                   <help>Enable Scatter-Gather</help>
diff --git a/python/vyos/ifconfig/ethernet.py b/python/vyos/ifconfig/ethernet.py
index 1bec45879..7cf79bead 100644
--- a/python/vyos/ifconfig/ethernet.py
+++ b/python/vyos/ifconfig/ethernet.py
@@ -1,4 +1,4 @@
-# Copyright 2019 VyOS maintainers and contributors <maintainers@vyos.io>
+# Copyright 2019-2021 VyOS maintainers and contributors <maintainers@vyos.io>
 #
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -17,9 +17,10 @@ import os
 import re
 
 from vyos.ifconfig.interface import Interface
-from vyos.validate import assert_list
 from vyos.util import run
 from vyos.util import dict_search
+from vyos.validate import assert_list
+from vyos.validate import assert_range
 
 @Interface.register
 class EthernetIf(Interface):
@@ -75,6 +76,13 @@ class EthernetIf(Interface):
         },
     }}
 
+    _sysfs_set = {**Interface._sysfs_set, **{
+        'rps': {
+            'validate': lambda cpu: assert_range(cpu, 0, 4294967295),
+            'location': '/sys/class/net/{ifname}/queues/rx-0/rps_cpus',
+        },
+    }}
+
     def get_driver_name(self):
         """
         Return the driver name used by NIC. Some NICs don't support all
@@ -231,6 +239,26 @@ class EthernetIf(Interface):
             raise ValueError("Value out of range")
         return self.set_interface('gso', 'on' if state else 'off')
 
+    def set_rps(self, state):
+        if not isinstance(state, bool):
+            raise ValueError("Value out of range")
+
+        rps_cpus = 0
+        if state:
+            # enable RPS on all available CPUs, RPS works woth a CPU bitmask,
+            # where each bit represents a CPU (core/thread). The formula below
+            # expands to rps_cpus = 255 for a 8 core system
+            rps_cpus = (1 << os.cpu_count()) -1
+
+            # XXX: we should probably reserve one core when the system is under
+            # high preasure so we can still have a core left for housekeeping.
+            # This is done by masking out the lowst bit so CPU0 is spared from
+            # receive packet steering.
+            rps_cpus &= ~1
+
+        # send bitmask representation as hex string without leading '0x'
+        return self.set_interface('rps', f'{rps_cpus:x}')
+
     def set_sg(self, state):
         """
         Enable Scatter-Gather support. State can be either True or False.
@@ -307,6 +335,9 @@ class EthernetIf(Interface):
         # GSO (generic segmentation offload)
         self.set_gso(dict_search('offload.gso', config) != None)
 
+        # RPS - Receive Packet Steering
+        self.set_rps(dict_search('offload.rps', config) != None)
+
         # scatter-gather option
         self.set_sg(dict_search('offload.sg', config) != None)
 
diff --git a/python/vyos/validate.py b/python/vyos/validate.py
index 98bd40f74..acd6086ff 100644
--- a/python/vyos/validate.py
+++ b/python/vyos/validate.py
@@ -1,4 +1,4 @@
-# Copyright 2018-2020 VyOS maintainers and contributors <maintainers@vyos.io>
+# Copyright 2018-2021 VyOS maintainers and contributors <maintainers@vyos.io>
 #
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -165,7 +165,7 @@ def assert_boolean(b):
 
 
 def assert_range(value, lower=0, count=3):
-    if int(value) not in range(lower,lower+count):
+    if int(value, 16) not in range(lower, lower+count):
         raise ValueError("Value out of range")
 
 
diff --git a/smoketest/scripts/cli/test_interfaces_ethernet.py b/smoketest/scripts/cli/test_interfaces_ethernet.py
index d5dcdc536..2d0a4827d 100755
--- a/smoketest/scripts/cli/test_interfaces_ethernet.py
+++ b/smoketest/scripts/cli/test_interfaces_ethernet.py
@@ -99,6 +99,31 @@ class EthernetInterfaceTest(BasicInterfaceTest.BaseTest):
                 flags = f.read()
             self.assertEqual(int(flags, 16) & 1, 0)
 
+    def test_offloading_rps(self):
+        # enable RPS on all available CPUs, RPS works woth a CPU bitmask,
+        # where each bit represents a CPU (core/thread). The formula below
+        # expands to rps_cpus = 255 for a 8 core system
+        rps_cpus = (1 << os.cpu_count()) -1
+
+        # XXX: we should probably reserve one core when the system is under
+        # high preasure so we can still have a core left for housekeeping.
+        # This is done by masking out the lowst bit so CPU0 is spared from
+        # receive packet steering.
+        rps_cpus &= ~1
+
+        for interface in self._interfaces:
+            self.session.set(self._base_path + [interface, 'offload', 'rps'])
+
+        self.session.commit()
+
+        for interface in self._interfaces:
+            cpus = read_file('/sys/class/net/eth1/queues/rx-0/rps_cpus')
+            # remove the nasty ',' separation on larger strings
+            cpus = cpus.replace(',','')
+            cpus = int(cpus, 16)
+
+            self.assertEqual(f'{cpus:x}', f'{rps_cpus:x}')
+
 
     def test_eapol_support(self):
         for interface in self._interfaces:
diff --git a/src/conf_mode/interfaces-ethernet.py b/src/conf_mode/interfaces-ethernet.py
index d8b637dd7..ed6396acf 100755
--- a/src/conf_mode/interfaces-ethernet.py
+++ b/src/conf_mode/interfaces-ethernet.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2019-2020 VyOS maintainers and contributors
+# Copyright (C) 2019-2021 VyOS maintainers and contributors
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 or later as
@@ -75,9 +75,15 @@ def verify(ethernet):
     verify_vrf(ethernet)
     verify_eapol(ethernet)
 
+    ifname = ethernet['ifname']
+    # verify offloading capabilities
+    if 'offload' in ethernet and 'rps' in ethernet['offload']:
+        if not os.path.exists(f'/sys/class/net/{ifname}/queues/rx-0/rps_cpus'):
+            raise ConfigError('Interface does not suport RPS!')
+
     # XDP requires multiple TX queues
     if 'xdp' in ethernet:
-        queues = glob('/sys/class/net/{ifname}/queues/tx-*'.format(**ethernet))
+        queues = glob(f'/sys/class/net/{ifname}/queues/tx-*')
         if len(queues) < 2:
             raise ConfigError('XDP requires additional TX queues, too few available!')