[ovs-dev] [PATCH v2 4/4] docs: Document ingress scheduling feature

[Billy O'Mahony]

Signed-off-by: Billy O'Mahony <billy.o.mahony at intel.com>
---
 Documentation/howto/dpdk.rst | 31 +++++++++++++++++++++++++++++++
 vswitchd/vswitch.xml         | 31 +++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/Documentation/howto/dpdk.rst b/Documentation/howto/dpdk.rst
index d7f6610..c7bfc01 100644
--- a/Documentation/howto/dpdk.rst
+++ b/Documentation/howto/dpdk.rst
@@ -188,6 +188,37 @@ respective parameter. To disable the flow control at tx side, run::
 
     $ ovs-vsctl set Interface dpdk-p0 options:tx-flow-ctrl=false
 
+Ingress Scheduling
+------------------
+
+The ingress scheduling feature is described in general in
+``ovs-vswitchd.conf.db (5)``.
+
+Interfaces of type ``dpdk`` support ingress scheduling only for
+either ether_type or else a fully specificed combination of src and
+dst ip address and port numbers for TCP or UDP packets.
+
+To prioritize packets for Precision Time Protocol:
+
+    $ ovs-vsctl set Interface dpdk-p0 \
+        other_config:ingress_sched=eth_type=0x88F7
+
+To prioritize UDP packets between specific IP source and destination:
+
+    $ ovs-vsctl set Interface dpdk-p0 \
+        other_config:ingress_sched=udp,ip_src=1.1.1.1,ip_dst=2.2.2.2,\
+        udp_src=11,udp_dst=22
+
+If unsupported ingress scheduling configuration is specified or it cannot be
+applied for any reason a warning message is logged and the Interface operates
+as if no ingress scheduling was configured.
+
+Interfaces of type ``dpdkvhostuserclient``, ``dpdkr`` and ``dpdkvhostuser`` do
+not support ingress scheduling.
+
+Currently only the match fields listed above are supported. No wildcarding of
+fields is supported.
+
 pdump
 -----
 
diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index 074535b..4564536 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -2923,6 +2923,37 @@
       </column>
     </group>
 
+    <group title="Ingress Scheduling">
+      <p>
+       Packets matching the ingress_sched value are prioritized. This means
+       some combination of:
+      </p>
+      <ul>
+        <li>
+         prioritized packets are forwarded to their destination port before
+         non-prioritized
+        </li>
+        <li>
+         prioritized packets are less likely to be dropped in an overloaded
+         situation than prioritized packets
+        </li>
+      </ul>
+      <p>
+       Ingress scheduling is supported with the best effort of the Interface.
+       It may be dependant on the interface type and it's supporting
+       implementation devices. Different interface types may have different
+       levels of support for the feature and the same interface type attached
+       to different devices (physical NICs or vhost ports, device driver,
+       NIC model) may also offer different levels of support.
+      </p>
+      <column name="other_config" key="ingress_sched">
+        <p>
+         The format of the ingress_sched field is specified in ovs-fields(7) in
+         the ``Matching'' and ``FIELD REFERENCE'' sections.
+        </p>
+      </column>
+    </group>
+
     <group title="Bidirectional Forwarding Detection (BFD)">
       <p>
         BFD, defined in RFC 5880 and RFC 5881, allows point-to-point
-- 
2.7.4