[dpdk-dev] [PATCH v2] net/mlx5: implement drop action in hardware classifier

[Shachar Beiser <shacharbe@mellanox.com>]

The current drop action is implemented as a queue tail drop,
requiring to instantiate multiple WQs to maintain high drop rate.
This commit, implements the drop action in hardware classifier.
This enables to reduce the amount of contexts needed for the drop,
without affecting the drop rate.

Signed-off-by: Shachar Beiser <shacharbe@mellanox.com>
---
 drivers/net/mlx5/Makefile    |  5 +++++
 drivers/net/mlx5/mlx5_flow.c | 19 +++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/drivers/net/mlx5/Makefile b/drivers/net/mlx5/Makefile
index c079959..daf8013 100644
--- a/drivers/net/mlx5/Makefile
+++ b/drivers/net/mlx5/Makefile
@@ -101,6 +101,11 @@ mlx5_autoconf.h.new: FORCE
 mlx5_autoconf.h.new: $(RTE_SDK)/buildtools/auto-config-h.sh
 	$Q $(RM) -f -- '$@'
 	$Q sh -- '$<' '$@' \
+		HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP \
+		infiniband/verbs_exp.h \
+		enum IBV_EXP_FLOW_SPEC_ACTION_DROP \
+		$(AUTOCONF_OUTPUT)
+	$Q sh -- '$<' '$@' \
 		HAVE_VERBS_IBV_EXP_CQ_COMPRESSED_CQE \
 		infiniband/verbs_exp.h \
 		enum IBV_EXP_CQ_COMPRESSED_CQE \
diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index adcbe3f..15f7516 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -53,7 +53,11 @@
 #include "mlx5_prm.h"
 
 /* Number of Work Queue necessary for the DROP queue. */
+#ifndef HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP
 #define MLX5_DROP_WQ_N 4
+#else
+#define MLX5_DROP_WQ_N 1
+#endif
 
 static int
 mlx5_flow_create_eth(const struct rte_flow_item *item,
@@ -994,6 +998,12 @@ struct mlx5_flow_action {
 {
 	struct rte_flow *rte_flow;
 
+#ifdef HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP
+
+	struct ibv_exp_flow_spec_action_drop *drop;
+
+	unsigned int size = sizeof(struct ibv_exp_flow_spec_action_drop);
+#endif
 	assert(priv->pd);
 	assert(priv->ctx);
 	rte_flow = rte_calloc(__func__, 1, sizeof(*rte_flow), 0);
@@ -1007,6 +1017,15 @@ struct mlx5_flow_action {
 	rte_flow->qp = priv->flow_drop_queue->qp;
 	if (!priv->started)
 		return rte_flow;
+#ifdef HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP
+	drop = (void *)((uintptr_t)flow->ibv_attr + flow->offset);
+	*drop = (struct ibv_exp_flow_spec_action_drop){
+			.type = IBV_EXP_FLOW_SPEC_ACTION_DROP,
+			.size = size,
+	};
+	++flow->ibv_attr->num_of_specs;
+	flow->offset += sizeof(struct ibv_exp_flow_spec_action_drop);
+#endif
 	rte_flow->ibv_flow = ibv_exp_create_flow(rte_flow->qp,
 						 rte_flow->ibv_attr);
 	if (!rte_flow->ibv_flow) {
-- 
1.8.3.1