[dpdk-dev] [PATCH 1/7] ethdev: introduce sample action for rte flow

[Jiawei Wang]

When using full offload, all traffic will be handled by the HW, and
directed to the requested vf or wire, the control application loses
visibility on the traffic.
So there's a need for an action that will enable the control application
some visibility.

The solution is introduced a new action that will sample the incoming
traffic and send a duplicated traffic in some predefined ratio to the
application, while the original packet will continue to the target
destination.

The packets sampled equals is '1/ratio', if the ratio value be set to 1
, means that the packets would 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 mellanox.com>
Acked-by: Ori Kam <orika at mellanox.com>
---
 doc/guides/prog_guide/rte_flow.rst     | 25 +++++++++++++++++++++++++
 doc/guides/rel_notes/release_20_08.rst |  6 ++++++
 lib/librte_ethdev/rte_flow.c           |  1 +
 lib/librte_ethdev/rte_flow.h           | 28 ++++++++++++++++++++++++++++
 4 files changed, 60 insertions(+)

diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
index d5dd18c..50dfe1f 100644
--- a/doc/guides/prog_guide/rte_flow.rst
+++ b/doc/guides/prog_guide/rte_flow.rst
@@ -2645,6 +2645,31 @@ 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 to a special queue or vport
+with the predefined ``ratio``, the packets sampled equals is '1/ratio'.
+All the packets continues 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.
+
+.. _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_08.rst b/doc/guides/rel_notes/release_20_08.rst
index 5cbc4ce..313e8d3 100644
--- a/doc/guides/rel_notes/release_20_08.rst
+++ b/doc/guides/rel_notes/release_20_08.rst
@@ -81,6 +81,12 @@ New Features
   * Added support for virtio queue statistics.
   * Added support for MTU update.
 
+* **Added flow-based traffic sampling support.**
+
+  Added new action: ``RTE_FLOW_ACTION_TYPE_SAMPLE`` to duplicate the matching
+  packets with given ratio and redirects to vport or queue. The sampled packets
+  also can be assigned with an additional optional actions.
+
 * **Updated Marvell octeontx2 ethdev PMD.**
 
   Updated Marvell octeontx2 driver with cn98xx support.
diff --git a/lib/librte_ethdev/rte_flow.c b/lib/librte_ethdev/rte_flow.c
index 1685be5..733871d 100644
--- a/lib/librte_ethdev/rte_flow.c
+++ b/lib/librte_ethdev/rte_flow.c
@@ -173,6 +173,7 @@ 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 b0e4199..c9cd80d 100644
--- a/lib/librte_ethdev/rte_flow.h
+++ b/lib/librte_ethdev/rte_flow.h
@@ -2099,6 +2099,13 @@ enum rte_flow_action_type {
 	 * see enum RTE_ETH_EVENT_FLOW_AGED
 	 */
 	RTE_FLOW_ACTION_TYPE_AGE,
+
+	/**
+	 * Redirects specific ratio of packets to vport or queue.
+	 *
+	 * See struct rte_flow_action_sample.
+	 */
+	RTE_FLOW_ACTION_TYPE_SAMPLE,
 };
 
 /**
@@ -2709,6 +2716,27 @@ 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 to a special queue or vport
+ * in the predefined probabiilty, All the packets continues 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 {
+	const 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