[ovs-dev] [PATCH 2/2] ofproto-dpif: Add ability to disable megaflows.

[Justin Pettit]

Add new "dpif/disable-megaflows" and "dpif/enable-megaflows" commands to
ovs-appctl to disable and enable megaflows, respectively.  By default,
megaflows are enabled, and these commands should only be used for
debugging.

Feature #18265

Requested-by: Ronghua Zhang <rzhang at vmware.com>
Signed-off-by: Justin Pettit <jpettit at nicira.com>
---
 ofproto/ofproto-dpif.c |   64 +++++++++++++++++++++++++++++++++++++++++++++---
 ofproto/ofproto-dpif.h |    4 +++
 2 files changed, 64 insertions(+), 4 deletions(-)

diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c
index 5ca16b7..92da91d 100644
--- a/ofproto/ofproto-dpif.c
+++ b/ofproto/ofproto-dpif.c
@@ -1080,6 +1080,8 @@ construct(struct ofproto *ofproto_)
     ofproto->n_hit = 0;
     ofproto->n_missed = 0;
 
+    ofproto->disable_megaflows = false;
+
     return error;
 }
 
@@ -3476,8 +3478,10 @@ handle_flow_miss_with_facet(struct flow_miss *miss, struct facet *facet,
         subfacet->path = want_path;
 
         ofpbuf_use_stack(&op->mask, &op->maskbuf, sizeof op->maskbuf);
-        odp_flow_key_from_mask(&op->mask, &facet->xout.wc.masks,
-                               &miss->flow, UINT32_MAX);
+        if (!ofproto->disable_megaflows) {
+            odp_flow_key_from_mask(&op->mask, &facet->xout.wc.masks,
+                                   &miss->flow, UINT32_MAX);
+        }
 
         op->xout_garbage = false;
         op->dpif_op.type = DPIF_OP_FLOW_PUT;
@@ -5064,8 +5068,10 @@ subfacet_install(struct subfacet *subfacet, const struct ofpbuf *odp_actions,
     }
 
     ofpbuf_use_stack(&mask, &maskbuf, sizeof maskbuf);
-    odp_flow_key_from_mask(&mask, &facet->xout.wc.masks,
-                           &facet->flow, UINT32_MAX);
+    if (!ofproto->disable_megaflows) {
+        odp_flow_key_from_mask(&mask, &facet->xout.wc.masks,
+                               &facet->flow, UINT32_MAX);
+    }
 
     ret = dpif_flow_put(subfacet->backer->dpif, flags, subfacet->key,
                         subfacet->key_len,  mask.data, mask.size,
@@ -6388,6 +6394,52 @@ ofproto_unixctl_dpif_dump_megaflows(struct unixctl_conn *conn,
     ds_destroy(&ds);
 }
 
+/* Disable using the megaflows.
+ *
+ * This command is only needed for advanced debugging, so it's not
+ * documented in the man page. */
+static void
+ofproto_unixctl_dpif_disable_megaflows(struct unixctl_conn *conn,
+                                       int argc OVS_UNUSED, const char *argv[],
+                                       void *aux OVS_UNUSED)
+{
+    struct ofproto_dpif *ofproto;
+
+    ofproto = ofproto_dpif_lookup(argv[1]);
+    if (!ofproto) {
+        unixctl_command_reply_error(conn, "no such bridge");
+        return;
+    }
+
+    ofproto->disable_megaflows = true;
+    flush(&ofproto->up);
+
+    unixctl_command_reply(conn, "megaflows disabled");
+}
+
+/* Re-enable using megaflows.
+ *
+ * This command is only needed for advanced debugging, so it's not
+ * documented in the man page. */
+static void
+ofproto_unixctl_dpif_enable_megaflows(struct unixctl_conn *conn,
+                                      int argc OVS_UNUSED, const char *argv[],
+                                      void *aux OVS_UNUSED)
+{
+    struct ofproto_dpif *ofproto;
+
+    ofproto = ofproto_dpif_lookup(argv[1]);
+    if (!ofproto) {
+        unixctl_command_reply_error(conn, "no such bridge");
+        return;
+    }
+
+    ofproto->disable_megaflows = false;
+    flush(&ofproto->up);
+
+    unixctl_command_reply(conn, "megaflows enabled");
+}
+
 static void
 ofproto_unixctl_dpif_dump_flows(struct unixctl_conn *conn,
                                 int argc OVS_UNUSED, const char *argv[],
@@ -6501,6 +6553,10 @@ ofproto_dpif_unixctl_init(void)
                              ofproto_unixctl_dpif_del_flows, NULL);
     unixctl_command_register("dpif/dump-megaflows", "bridge", 1, 1,
                              ofproto_unixctl_dpif_dump_megaflows, NULL);
+    unixctl_command_register("dpif/disable-megaflows", "bridge", 1, 1,
+                             ofproto_unixctl_dpif_disable_megaflows, NULL);
+    unixctl_command_register("dpif/enable-megaflows", "bridge", 1, 1,
+                             ofproto_unixctl_dpif_enable_megaflows, NULL);
 }
 
 /* Linux VLAN device support (e.g. "eth0.10" for VLAN 10.)
diff --git a/ofproto/ofproto-dpif.h b/ofproto/ofproto-dpif.h
index 0704297..eeb41c3 100644
--- a/ofproto/ofproto-dpif.h
+++ b/ofproto/ofproto-dpif.h
@@ -120,6 +120,10 @@ struct ofproto_dpif {
     /* Per ofproto's dpif stats. */
     uint64_t n_hit;
     uint64_t n_missed;
+
+    /* Disable wildcarding the datapath's flows (megaflows) when
+     * "ovs-appctl dpif/disable-megaflows <br>" is called. */
+    bool disable_megaflows;
 };
 
 struct ofport_dpif {
-- 
1.7.5.4