ovs-ofctl: Group NXM field matches into own subsection of man page.

A number of new matching fields are going to be introduced shortly that
will require NXM (Nicira Extended Match).  Rather than repeating the
same description for each field, this change groups them together with a
common preface.

diff --git a/utilities/ovs-ofctl.8.in b/utilities/ovs-ofctl.8.in
index 9137d7d..d83a50b 100644 (file)
--- a/utilities/ovs-ofctl.8.in
+++ b/utilities/ovs-ofctl.8.in
@@ -4,7 +4,7 @@
 .  ns
 .  IP "\\$1"
 ..
-.TH ovs\-ofctl 8 "January 2010" "Open vSwitch" "Open vSwitch Manual"
+.TH ovs\-ofctl 8 "January 2011" "Open vSwitch" "Open vSwitch Manual"
 .ds PN ovs\-ofctl
 .
 .SH NAME
@@ -337,32 +337,31 @@ as a decimal number between 0 and 255, inclusive.
 .IP
 When \fBdl_type\fR and \fBnw_proto\fR take other values, the values of
 these settings are ignored (see \fBFlow Syntax\fR above).
+.
+.PP
+The following field assignments require support for the NXM (Nicira
+Extended Match) extension to OpenFlow.  When one of these is specified,
+\fBovs\-ofctl\fR will automatically attempt to negotiate use of this
+extension.  If the switch does not support NXM, then \fBovs\-ofctl\fR
+will report a fatal error.
+.
 .IP \fBtun_id=\fItunnel-id\fR[\fB/\fImask\fR]
 Matches tunnel identifier \fItunnel-id\fR.  Only packets that arrive
 over a tunnel that carries a key (e.g. GRE with the RFC 2890 key
 extension) will have a nonzero tunnel ID.  If \fImask\fR is omitted,
-\fItunnel-id\fR is the exact tunnel ID to match; \fImask\fR is
+\fItunnel-id\fR is the exact tunnel ID to match; if \fImask\fR is
 specified, then a 1-bit in \fImask\fR indicates that the corresponding
 bit in \fItunnel-id\fR must match exactly, and a 0-bit wildcards that
 bit.
 .IP
-\fBtun_id\fR requires use of one of two Nicira extensions to OpenFlow:
-.RS
-.IP "NXM (Nicira Extended Match)"
-This extension fully supports \fBtun_id\fR. 
-.IP "Tunnel ID from Cookie"
-This extension supports \fBtun_id\fR with three caveats: the top 32 bits
-of the \fBcookie\fR (see below) are used for \fItunnel-id\fR and thus
-unavailable for other use, specifying \fBtun_id\fR on
-\fBdump\-flows\fR or \fBdump\-aggregate\fR has no effect, and
-\fImask\fR is not supported.
-.RE
-.IP
-When \fBtun_id\fR is specified, \fBovs\-ofctl\fR will automatically
-attempt to negotiate use of one of these extensions.  It will use the
-``tunnel ID from cookie'' extension if neither caveat applies and NXM
-otherwise.  If the switch does not support the needed extension, then
-\fBovs\-ofctl\fR will report a fatal error.
+In an attempt to be compatible with more switches, \fBovs\-ofctl\fR will
+prefer to use the ``tunnel ID from cookie'' Nicira extension to NXM.
+The use of this extension comes with three caveats: the top 32 bits of
+the \fBcookie\fR (see below) are used for \fItunnel-id\fR and thus
+unavailable for other use, specifying \fBtun_id\fR on \fBdump\-flows\fR
+or \fBdump\-aggregate\fR has no effect, and \fImask\fR is not supported.
+If any of these caveats apply, \fBovs-ofctl\fR will use NXM.
+.
 .IP "\fBreg\fIidx\fB=\fIvalue\fR[\fB/\fImask\fR]"
 Matches \fIvalue\fR either exactly or with optional \fImask\fR in
 register number \fIidx\fR.  The valid range of \fIidx\fR depends on
@@ -374,12 +373,6 @@ exactly, and a 0-bit wildcards that bit.
 .IP
 When a packet enters an OpenFlow switch, all of the registers are set
 to 0.  Only explicit Nicira extension actions change register values.
-.IP
-Register matches require support for the NXM (Nicira Extended Match)
-extension to OpenFlow.  When a register match is specified,
-\fBovs\-ofctl\fR will automatically attempt to negotiate use of this
-extension.  If the switch does not support NXM, then \fBovs\-ofctl\fR
-will report a fatal error.
 .
 .PP
 The following shorthand notations are also available: