[dpdk-dev] [PATCH v9 1/3] ethdev: introduce sample action for rte flow

[Jiawei Wang]

When using full offload, all traffic will be handled by the HW, and
forwarded to the requested VF or wire and the control application does
not see this traffic anymore. So there's a need for an action that
enables the control application some forwarded traffic visibility.

The solution introduces a new action that will sample the incoming
traffic and send a duplicated traffic with the specified ratio to the
application, while the original packet will continue to the target
destination.

The packets sampled equals is '1/ratio', the ratio value set to 1
means that the packets will be completely mirrored. The sample packet
can be assigned with different set of actions from the original packet.

In order to support the sample packet in rte_flow, new rte_flow action
definition RTE_FLOW_ACTION_TYPE_SAMPLE and structure rte_flow_action_sample
will be introduced.

Signed-off-by: Jiawei Wang <jiaweiw at nvidia.com>
Acked-by: Ori Kam <orika at nvidia.com>
Acked-by: Jerin Jacob <jerinj at marvell.com>
Acked-by: Andrew Rybchenko <arybchenko at solarflare.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
---
 doc/guides/prog_guide/rte_flow.rst     | 25 +++++++++++++++++++++++++
 doc/guides/rel_notes/release_20_11.rst |  6 ++++++
 lib/librte_ethdev/rte_flow.c           |  1 +
 lib/librte_ethdev/rte_flow.h           | 30 ++++++++++++++++++++++++++++++
 4 files changed, 62 insertions(+)

diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
index 119b128..a0046a2 100644
--- a/doc/guides/prog_guide/rte_flow.rst
+++ b/doc/guides/prog_guide/rte_flow.rst
@@ -2666,6 +2666,31 @@ timeout passed without any matching on the flow.
    | ``context``  | user input flow context         |
    +--------------+---------------------------------+
 
+Action: ``SAMPLE``
+^^^^^^^^^^^^^^^^^^
+
+Adds a sample action to a matched flow.
+
+The matching packets will be duplicated with the specified ``ratio`` and
+applied with own set of actions with a fate action, the packets sampled
+equals is '1/ratio'. All the packets continue to the target destination.
+
+When the ``ratio`` is set to 1 then the packets will be 100% mirrored.
+``actions`` represent the different set of actions for the sampled or mirrored
+packets, and must have a fate action.
+
+.. _table_rte_flow_action_sample:
+
+.. table:: SAMPLE
+
+   +--------------+---------------------------------+
+   | Field        | Value                           |
+   +==============+=================================+
+   | ``ratio``    | 32 bits sample ratio value      |
+   +--------------+---------------------------------+
+   | ``actions``  | sub-action list for sampling    |
+   +--------------+---------------------------------+
+
 Negative types
 ~~~~~~~~~~~~~~
 
diff --git a/doc/guides/rel_notes/release_20_11.rst b/doc/guides/rel_notes/release_20_11.rst
index b063764..f3aef67 100644
--- a/doc/guides/rel_notes/release_20_11.rst
+++ b/doc/guides/rel_notes/release_20_11.rst
@@ -118,6 +118,12 @@ New Features
   * Extern objects and functions can be plugged into the pipeline.
   * Transaction-oriented table updates.
 
+* **Added flow-based traffic sampling support.**
+
+  Added new action: ``RTE_FLOW_ACTION_TYPE_SAMPLE`` to duplicate the matching
+  packets with specified ratio, and apply with own set of actions with a fate
+  action. When the ratio is set to 1 then the packets will be 100% mirrored.
+
 
 Removed Items
 -------------
diff --git a/lib/librte_ethdev/rte_flow.c b/lib/librte_ethdev/rte_flow.c
index 8d1b279..0a8a7a2 100644
--- a/lib/librte_ethdev/rte_flow.c
+++ b/lib/librte_ethdev/rte_flow.c
@@ -174,6 +174,7 @@ struct rte_flow_desc_data {
 	MK_FLOW_ACTION(SET_IPV4_DSCP, sizeof(struct rte_flow_action_set_dscp)),
 	MK_FLOW_ACTION(SET_IPV6_DSCP, sizeof(struct rte_flow_action_set_dscp)),
 	MK_FLOW_ACTION(AGE, sizeof(struct rte_flow_action_age)),
+	MK_FLOW_ACTION(SAMPLE, sizeof(struct rte_flow_action_sample)),
 };
 
 int
diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h
index da8bfa5..fa70d40 100644
--- a/lib/librte_ethdev/rte_flow.h
+++ b/lib/librte_ethdev/rte_flow.h
@@ -2132,6 +2132,14 @@ enum rte_flow_action_type {
 	 * see enum RTE_ETH_EVENT_FLOW_AGED
 	 */
 	RTE_FLOW_ACTION_TYPE_AGE,
+
+	/**
+	 * The matching packets will be duplicated with specified ratio and
+	 * applied with own set of actions with a fate action.
+	 *
+	 * See struct rte_flow_action_sample.
+	 */
+	RTE_FLOW_ACTION_TYPE_SAMPLE,
 };
 
 /**
@@ -2742,6 +2750,28 @@ struct rte_flow_action {
 struct rte_flow;
 
 /**
+ * @warning
+ * @b EXPERIMENTAL: this structure may change without prior notice
+ *
+ * RTE_FLOW_ACTION_TYPE_SAMPLE
+ *
+ * Adds a sample action to a matched flow.
+ *
+ * The matching packets will be duplicated with specified ratio and applied
+ * with own set of actions with a fate action, the sampled packet could be
+ * redirected to queue or port. All the packets continue processing on the
+ * default flow path.
+ *
+ * When the sample ratio is set to 1 then the packets will be 100% mirrored.
+ * Additional action list be supported to add for sampled or mirrored packets.
+ */
+struct rte_flow_action_sample {
+	uint32_t ratio; /**< packets sampled equals to '1/ratio'. */
+	const struct rte_flow_action *actions;
+		/**< sub-action list specific for the sampling hit cases. */
+};
+
+/**
  * Verbose error types.
  *
  * Most of them provide the type of the object referenced by struct
-- 
1.8.3.1