other-config: Add tc-policy switch to control tc flower flag

Add a new configuration tc-policy option that controls tc
flower flag. Possible options are none, skip_sw, skip_hw.
The default is none which is to insert the rule both to sw and hw.
This option is only relevant if hw-offload is enabled.

Signed-off-by: Paul Blakey <[email protected]>
Reviewed-by: Roi Dayan <[email protected]>
Acked-by: Flavio Leitner <[email protected]>
Signed-off-by: Simon Horman <[email protected]>

lib/netdev.c

@@ -54,6 +54,9 @@
 #include "openvswitch/vlog.h"
 #include "flow.h"
 #include "util.h"
+#ifdef __linux__
+#include "tc.h"
+#endif
 
 VLOG_DEFINE_THIS_MODULE(netdev);
 
@@ -2136,6 +2139,9 @@ netdev_set_flow_api_enabled(const struct smap *ovs_other_config)
 
             VLOG_INFO("netdev: Flow API Enabled");
 
+            tc_set_policy(smap_get_def(ovs_other_config, "tc-policy",
+                                       TC_POLICY_DEFAULT));
+
             ovsthread_once_done(&once);
         }
     }

lib/tc.c

@@ -39,6 +39,14 @@ VLOG_DEFINE_THIS_MODULE(tc);
 
 static struct vlog_rate_limit error_rl = VLOG_RATE_LIMIT_INIT(60, 5);
 
+enum tc_offload_policy {
+    TC_POLICY_NONE,
+    TC_POLICY_SKIP_SW,
+    TC_POLICY_SKIP_HW
+};
+
+static enum tc_offload_policy tc_policy = TC_POLICY_NONE;
+
 struct tcmsg *
 tc_make_request(int ifindex, int type, unsigned int flags,
                 struct ofpbuf *request)
@@ -739,6 +747,18 @@ tc_get_flower(int ifindex, int prio, int handle, struct tc_flower *flower)
     return error;
 }
 
+static int
+tc_get_tc_cls_policy(enum tc_offload_policy policy)
+{
+    if (policy == TC_POLICY_SKIP_HW) {
+        return TCA_CLS_FLAGS_SKIP_HW;
+    } else if (policy == TC_POLICY_SKIP_SW) {
+        return TCA_CLS_FLAGS_SKIP_SW;
+    }
+
+    return 0;
+}
+
 static void
 nl_msg_put_act_push_vlan(struct ofpbuf *request, uint16_t vid, uint8_t prio)
 {
@@ -1044,7 +1064,7 @@ nl_msg_put_flower_options(struct ofpbuf *request, struct tc_flower *flower)
         }
     }
 
-    nl_msg_put_u32(request, TCA_FLOWER_FLAGS, 0);
+    nl_msg_put_u32(request, TCA_FLOWER_FLAGS, tc_get_tc_cls_policy(tc_policy));
 
     if (flower->tunnel.tunnel) {
         nl_msg_put_flower_tunnel(request, flower);
@@ -1089,3 +1109,24 @@ tc_replace_flower(int ifindex, uint16_t prio, uint32_t handle,
 
     return error;
 }
+
+void
+tc_set_policy(const char *policy)
+{
+    if (!policy) {
+        return;
+    }
+
+    if (!strcmp(policy, "skip_sw")) {
+        tc_policy = TC_POLICY_SKIP_SW;
+    } else if (!strcmp(policy, "skip_hw")) {
+        tc_policy = TC_POLICY_SKIP_HW;
+    } else if (!strcmp(policy, "none")) {
+        tc_policy = TC_POLICY_NONE;
+    } else {
+        VLOG_WARN("tc: Invalid policy '%s'", policy);
+        return;
+    }
+
+    VLOG_INFO("tc: Using policy '%s'", policy);
+}

lib/tc.h

@@ -36,6 +36,8 @@
 
 #define TC_INGRESS_PARENT TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS)
 
+#define TC_POLICY_DEFAULT "none"
+
 /* Returns tc handle 'major':'minor'. */
 static inline unsigned int
 tc_make_handle(unsigned int major, unsigned int minor)
@@ -152,5 +154,6 @@ int tc_flush(int ifindex);
 int tc_dump_flower_start(int ifindex, struct nl_dump *dump);
 int parse_netlink_to_tc_flower(struct ofpbuf *reply,
                                struct tc_flower *flower);
+void tc_set_policy(const char *policy);
 
 #endif /* tc.h */

vswitchd/vswitch.xml

@@ -195,6 +195,23 @@
         </p>
       </column>
 
+      <column name="other_config" key="tc-policy"
+              type='{"type": "string"}'>
+        <p>
+            Specified the policy used with HW offloading.
+            Options:
+                <code>none</code>    - Add software rule and offload rule to HW.
+                <code>skip_sw</code> - Offload rule to HW only.
+                <code>skip_hw</code> - Add software rule without offloading rule to HW.
+        </p>
+        <p>
+            This is only relevant if HW offloading is enabled (hw-offload).
+        </p>
+        <p>
+          The default value is <code>none</code>.
+        </p>
+      </column>
+
       <column name="other_config" key="dpdk-init"
               type='{"type": "boolean"}'>
         <p>