From 4103f6d275673ba0b5f114d567ca8d663171b1e2 Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@nicira.com>
Date: Wed, 19 Aug 2015 11:53:04 -0700
Subject: [PATCH] ovn: Add comments to encourage syncing MFF_LOG_* with
 documentation.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Russell Bryant <rbryant@redhat.com>
---
 ovn/controller/lflow.h     |  5 ++++-
 ovn/ovn-architecture.7.xml | 22 +++++++++++++++-------
 2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/ovn/controller/lflow.h b/ovn/controller/lflow.h
index 59fe5599a..5cac76c90 100644
--- a/ovn/controller/lflow.h
+++ b/ovn/controller/lflow.h
@@ -53,7 +53,10 @@ struct uuid;
 /* The number of tables for the ingress and egress pipelines. */
 #define LOG_PIPELINE_LEN 16
 
-/* Logical fields. */
+/* Logical fields.
+ *
+ * These values are documented in ovn-architecture(7), please update the
+ * documentation if you change any of them. */
 #define MFF_LOG_DATAPATH MFF_METADATA /* Logical datapath (64 bits). */
 #define MFF_LOG_INPORT   MFF_REG6     /* Logical input port (32 bits). */
 #define MFF_LOG_OUTPORT  MFF_REG7     /* Logical output port (32 bits). */
diff --git a/ovn/ovn-architecture.7.xml b/ovn/ovn-architecture.7.xml
index 2424836c9..c9ac59796 100644
--- a/ovn/ovn-architecture.7.xml
+++ b/ovn/ovn-architecture.7.xml
@@ -620,24 +620,32 @@
     <dt>logical datapath field</dt>
     <dd>
       A field that denotes the logical datapath through which a packet is being
-      processed.  OVN uses the field that OpenFlow 1.1+ simply (and
-      confusingly) calls ``metadata'' to store the logical datapath.  (This
-      field is passed across tunnels as part of the tunnel key.)
+      processed.
+      <!-- Keep the following in sync with MFF_LOG_DATAPATH in
+           ovn/controller/lflow.h. -->
+      OVN uses the field that OpenFlow 1.1+ simply (and confusingly) calls
+      ``metadata'' to store the logical datapath.  (This field is passed across
+      tunnels as part of the tunnel key.)
     </dd>
 
     <dt>logical input port field</dt>
     <dd>
       A field that denotes the logical port from which the packet
-      entered the logical datapath.  OVN stores this in Nicira extension
-      register number 6.  (This field is passed across tunnels as part
-      of the tunnel key.)
+      entered the logical datapath.
+      <!-- Keep the following in sync with MFF_LOG_INPORT in
+           ovn/controller/lflow.h. -->
+      OVN stores this in Nicira extension register number 6.  (This field is
+      passed across tunnels as part of the tunnel key.)
     </dd>
 
     <dt>logical output port field</dt>
     <dd>
       A field that denotes the logical port from which the packet will
       leave the logical datapath.  This is initialized to 0 at the
-      beginning of the logical ingress pipeline.  OVN stores this in
+      beginning of the logical ingress pipeline.
+      <!-- Keep the following in sync with MFF_LOG_OUTPORT in
+           ovn/controller/lflow.h. -->
+      OVN stores this in
       Nicira extension register number 7.  (This field is passed across
       tunnels as part of the tunnel key.)
     </dd>
-- 
2.20.1