[PATCH v5] ethdev: add send to kernel action

[Michael Savisko <michaelsav@nvidia.com>]

In some cases application may receive a packet that should have been
received by the kernel. In this case application uses KNI or other means
to transfer the packet to the kernel.

With bifurcated driver we can have a rule to route packets matching
a pattern (example: IPv4 packets) to the DPDK application and the rest
of the traffic will be received by the kernel.
But if we want to receive most of the traffic in DPDK except specific
pattern (example: ICMP packets) that should be processed by the kernel,
then it's easier to re-route these packets with a single rule.

This commit introduces new rte_flow action which allows application to
re-route packets directly to the kernel without software involvement.

Add new testpmd rte_flow action 'send_to_kernel'. The application
may use this action to route the packet to the kernel while still
in the HW.

Example with testpmd command:

flow create 0 ingress priority 0 group 1 pattern eth type spec 0x0800
type mask 0xffff / end actions send_to_kernel / end

Signed-off-by: Michael Savisko <michaelsav@nvidia.com>
Acked-by: Ori Kam <orika@nvidia.com>
---
v5:
- added description of the feature to release notes

v4:
- improve description comment above RTE_FLOW_ACTION_TYPE_SEND_TO_KERNEL
http://patches.dpdk.org/project/dpdk/patch/20220929145445.181369-1-michaelsav@nvidia.com/

v3:
http://patches.dpdk.org/project/dpdk/patch/20220919155013.61473-1-michaelsav@nvidia.com/

v2:
http://patches.dpdk.org/project/dpdk/patch/20220914093219.11728-1-michaelsav@nvidia.com/

---
 app/test-pmd/cmdline_flow.c                 |  9 +++++++++
 doc/guides/rel_notes/release_22_11.rst      |  5 +++++
 doc/guides/testpmd_app_ug/testpmd_funcs.rst |  3 +++
 lib/ethdev/rte_flow.c                       |  1 +
 lib/ethdev/rte_flow.h                       | 12 ++++++++++++
 5 files changed, 30 insertions(+)

diff --git a/app/test-pmd/cmdline_flow.c b/app/test-pmd/cmdline_flow.c
index 91c6950b60..9e299b8335 100644
--- a/app/test-pmd/cmdline_flow.c
+++ b/app/test-pmd/cmdline_flow.c
@@ -622,6 +622,7 @@ enum index {
 	ACTION_PORT_REPRESENTOR_PORT_ID,
 	ACTION_REPRESENTED_PORT,
 	ACTION_REPRESENTED_PORT_ETHDEV_PORT_ID,
+	ACTION_SEND_TO_KERNEL,
 };
 
 /** Maximum size for pattern in struct rte_flow_item_raw. */
@@ -1888,6 +1889,7 @@ static const enum index next_action[] = {
 	ACTION_CONNTRACK_UPDATE,
 	ACTION_PORT_REPRESENTOR,
 	ACTION_REPRESENTED_PORT,
+	ACTION_SEND_TO_KERNEL,
 	ZERO,
 };
 
@@ -6098,6 +6100,13 @@ static const struct token token_list[] = {
 					width)),
 		.call = parse_vc_conf,
 	},
+	[ACTION_SEND_TO_KERNEL] = {
+		.name = "send_to_kernel",
+		.help = "send packets to kernel",
+		.priv = PRIV_ACTION(SEND_TO_KERNEL, 0),
+		.next = NEXT(NEXT_ENTRY(ACTION_NEXT)),
+		.call = parse_vc,
+	},
 	/* Top level command. */
 	[SET] = {
 		.name = "set",
diff --git a/doc/guides/rel_notes/release_22_11.rst b/doc/guides/rel_notes/release_22_11.rst
index c6bcb45100..7783eeb489 100644
--- a/doc/guides/rel_notes/release_22_11.rst
+++ b/doc/guides/rel_notes/release_22_11.rst
@@ -114,6 +114,11 @@ New Features
   * Added ``rte_event_eth_tx_adapter_queue_stop`` to stop the Tx Adapter
     from enqueueing any packets to the Tx queue.
 
+* **Added new rte_flow action SEND_TO_KERNEL.**
+
+  Added new rte_flow action which allows application to re-route packets
+  directly to the kernel without software involvement.
+
 
 Removed Items
 -------------
diff --git a/doc/guides/testpmd_app_ug/testpmd_funcs.rst b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
index b4e9d978ba..a5b6fb12e3 100644
--- a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
+++ b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
@@ -3691,6 +3691,9 @@ This section lists supported pattern items and their attributes, if any.
 
   - ``color {value}``: Meter color value(green/yellow/red).
 
+- ``send_to_kernel``: send packets to kernel.
+
+
 Actions list
 ^^^^^^^^^^^^
 
diff --git a/lib/ethdev/rte_flow.c b/lib/ethdev/rte_flow.c
index fd802f87a2..a6b1bf21c4 100644
--- a/lib/ethdev/rte_flow.c
+++ b/lib/ethdev/rte_flow.c
@@ -257,6 +257,7 @@ static const struct rte_flow_desc_data rte_flow_desc_action[] = {
 	MK_FLOW_ACTION(PORT_REPRESENTOR, sizeof(struct rte_flow_action_ethdev)),
 	MK_FLOW_ACTION(REPRESENTED_PORT, sizeof(struct rte_flow_action_ethdev)),
 	MK_FLOW_ACTION(METER_MARK, sizeof(struct rte_flow_action_meter_mark)),
+	MK_FLOW_ACTION(SEND_TO_KERNEL, 0),
 };
 
 int
diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h
index 49aaf05b67..c895c574cd 100644
--- a/lib/ethdev/rte_flow.h
+++ b/lib/ethdev/rte_flow.h
@@ -2797,6 +2797,18 @@ enum rte_flow_action_type {
 	 * See file rte_mtr.h for MTR profile object configuration.
 	 */
 	RTE_FLOW_ACTION_TYPE_METER_MARK,
+
+	/**
+	 * Send packets to the kernel, without going to userspace at all.
+	 * The packets will be received by the kernel driver sharing
+	 * the same device as the DPDK port on which this action is
+	 * configured. This action is mostly suits bifurcated driver
+	 * model.
+	 * This is an ingress non-transfer action only.
+	 *
+	 * No associated configuration structure.
+	 */
+	RTE_FLOW_ACTION_TYPE_SEND_TO_KERNEL,
 };
 
 /**
-- 
2.27.0