netdev-dpdk: Add new DPDK RFC 4115 egress policer

This patch adds a new policer to the DPDK datapath based on RFC 4115's
Two-Rate, Three-Color marker. It's a two-level hierarchical policer
which first does a color-blind marking of the traffic at the queue
level, followed by a color-aware marking at the port level. At the end
traffic marked as Green or Yellow is forwarded, Red is dropped. For
details on how traffic is marked, see RFC 4115.

This egress policer can be used to limit traffic at different rated
based on the queues the traffic is in. In addition, it can also be used
to prioritize certain traffic over others at a port level.

For example, the following configuration will limit the traffic rate at a
port level to a maximum of 2000 packets a second (64 bytes IPv4 packets).
100pps as CIR (Committed Information Rate) and 1000pps as EIR (Excess
Information Rate). High priority traffic is routed to queue 10, which marks
all traffic as CIR, i.e. Green. All low priority traffic, queue 20, is
marked as EIR, i.e. Yellow.

ovs-vsctl --timeout=5 set port dpdk1 qos=@myqos -- \
  --id=@myqos create qos type=trtcm-policer \
  other-config:cir=52000 other-config:cbs=2048 \
  other-config:eir=52000 other-config:ebs=2048  \
  queues:10=@dpdk1Q10 queues:20=@dpdk1Q20 -- \
  --id=@dpdk1Q10 create queue \
    other-config:cir=41600000 other-config:cbs=2048 \
    other-config:eir=0 other-config:ebs=0 -- \
  --id=@dpdk1Q20 create queue \
    other-config:cir=0 other-config:cbs=0 \
    other-config:eir=41600000 other-config:ebs=2048 \

This configuration accomplishes that the high priority traffic has a
guaranteed bandwidth egressing the ports at CIR (1000pps), but it can also
use the EIR, so a total of 2000pps at max. These additional 1000pps is
shared with the low priority traffic. The low priority traffic can use at
maximum 1000pps.

Signed-off-by: Eelco Chaudron <[email protected]>
Signed-off-by: Ian Stokes <[email protected]>

Documentation/topics/dpdk/qos.rst

@@ -33,6 +33,9 @@ datapath. These are referred to as *QoS* and *Rate Limiting*, respectively.
 QoS (Egress Policing)
 ---------------------
 
+Single Queue Policer
+~~~~~~~~~~~~~~~~~~~~
+
 Assuming you have a :doc:`vhost-user port <vhost-user>` transmitting traffic
 consisting of packets of size 64 bytes, the following command would limit the
 egress transmission rate of the port to ~1,000,000 packets per second::
@@ -49,6 +52,46 @@ To clear the QoS configuration from the port and ovsdb, run::
 
     $ ovs-vsctl destroy QoS vhost-user0 -- clear Port vhost-user0 qos
 
+
+Multi Queue Policer
+~~~~~~~~~~~~~~~~~~~
+
+In addition to the egress-policer OVS-DPDK also has support for a RFC
+4115's Two-Rate, Three-Color marker meter. It's a two-level hierarchical
+policer which first does a color-blind marking of the traffic at the queue
+level, followed by a color-aware marking at the port level. At the end
+traffic marked as Green or Yellow is forwarded, Red is dropped. For
+details on how traffic is marked, see RFC 4115.
+
+This egress policer can be used to limit traffic at different rated
+based on the queues the traffic is in. In addition, it can also be used
+to prioritize certain traffic over others at a port level.
+
+For example, the following configuration will limit the traffic rate at a
+port level to a maximum of 2000 packets a second (64 bytes IPv4 packets).
+100pps as CIR (Committed Information Rate) and 1000pps as EIR (Excess
+Information Rate). High priority traffic is routed to queue 10, which marks
+all traffic as CIR, i.e. Green. All low priority traffic, queue 20, is
+marked as EIR, i.e. Yellow::
+
+    $ ovs-vsctl --timeout=5 set port dpdk1 qos=@myqos -- \
+        --id=@myqos create qos type=trtcm-policer \
+        other-config:cir=52000 other-config:cbs=2048 \
+        other-config:eir=52000 other-config:ebs=2048  \
+        queues:10=@dpdk1Q10 queues:20=@dpdk1Q20 -- \
+         --id=@dpdk1Q10 create queue \
+          other-config:cir=41600000 other-config:cbs=2048 \
+          other-config:eir=0 other-config:ebs=0 -- \
+         --id=@dpdk1Q20 create queue \
+           other-config:cir=0 other-config:cbs=0 \
+           other-config:eir=41600000 other-config:ebs=2048 \
+
+This configuration accomplishes that the high priority traffic has a
+guaranteed bandwidth egressing the ports at CIR (1000pps), but it can also
+use the EIR, so a total of 2000pps at max. These additional 1000pps is
+shared with the low priority traffic. The low priority traffic can use at
+maximum 1000pps.
+
 Refer to ``vswitch.xml`` for more details on egress policer.
 
 Rate Limiting (Ingress Policing)