[dpdk-dev] [PATCH v1 19/29] net/mlx4: add flow support for multicast traffic

[Adrien Mazarguil <adrien.mazarguil@6wind.com>]

Give users the ability to create flow rules that match all multicast
traffic. Like promiscuous flow rules, they come with restrictions such as
not allowing additional matching criteria.

Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
---
 doc/guides/nics/features/mlx4.ini |  1 +
 drivers/net/mlx4/mlx4_flow.c      | 17 +++++++++++++++--
 drivers/net/mlx4/mlx4_flow.h      |  1 +
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/doc/guides/nics/features/mlx4.ini b/doc/guides/nics/features/mlx4.ini
index bfe0eb1..9e3ba34 100644
--- a/doc/guides/nics/features/mlx4.ini
+++ b/doc/guides/nics/features/mlx4.ini
@@ -13,6 +13,7 @@ Queue start/stop     = Y
 MTU update           = Y
 Jumbo frame          = Y
 Unicast MAC filter   = Y
+Multicast MAC filter = Y
 SR-IOV               = Y
 VLAN filter          = Y
 Basic stats          = Y
diff --git a/drivers/net/mlx4/mlx4_flow.c b/drivers/net/mlx4/mlx4_flow.c
index 47a6a6a..2ff1c69 100644
--- a/drivers/net/mlx4/mlx4_flow.c
+++ b/drivers/net/mlx4/mlx4_flow.c
@@ -107,7 +107,9 @@ struct mlx4_drop {
  *
  * Additional mlx4-specific constraints on supported fields:
  *
- * - No support for partial masks.
+ * - No support for partial masks, except in the specific case of matching
+ *   all multicast traffic (@p spec->dst and @p mask->dst equal to
+ *   01:00:00:00:00:00).
  * - Not providing @p item->spec or providing an empty @p mask->dst is
  *   *only* supported if the rule doesn't specify additional matching
  *   criteria (i.e. rule is promiscuous-like).
@@ -152,6 +154,13 @@ mlx4_flow_merge_eth(struct rte_flow *flow,
 			goto error;
 		} else if (!sum_dst) {
 			flow->promisc = 1;
+		} else if (sum_dst == 1 && mask->dst.addr_bytes[0] == 1) {
+			if (!(spec->dst.addr_bytes[0] & 1)) {
+				msg = "mlx4 does not support the explicit"
+					" exclusion of all multicast traffic";
+				goto error;
+			}
+			flow->allmulti = 1;
 		} else if (sum_dst != (UINT8_C(0xff) * ETHER_ADDR_LEN)) {
 			msg = "mlx4 does not support matching partial"
 				" Ethernet fields";
@@ -164,6 +173,10 @@ mlx4_flow_merge_eth(struct rte_flow *flow,
 		flow->ibv_attr->type = IBV_FLOW_ATTR_ALL_DEFAULT;
 		return 0;
 	}
+	if (flow->allmulti) {
+		flow->ibv_attr->type = IBV_FLOW_ATTR_MC_DEFAULT;
+		return 0;
+	}
 	++flow->ibv_attr->num_of_specs;
 	eth = (void *)((uintptr_t)flow->ibv_attr + flow->ibv_attr_size);
 	*eth = (struct ibv_flow_spec_eth) {
@@ -615,7 +628,7 @@ mlx4_flow_prepare(struct priv *priv,
 			flow->internal = 1;
 			continue;
 		}
-		if (flow->promisc) {
+		if (flow->promisc || flow->allmulti) {
 			msg = "mlx4 does not support additional matching"
 				" criteria combined with indiscriminate"
 				" matching on Ethernet headers";
diff --git a/drivers/net/mlx4/mlx4_flow.h b/drivers/net/mlx4/mlx4_flow.h
index fcdf461..134e14d 100644
--- a/drivers/net/mlx4/mlx4_flow.h
+++ b/drivers/net/mlx4/mlx4_flow.h
@@ -68,6 +68,7 @@ struct rte_flow {
 	uint32_t internal:1; /**< Internal flow rule outside isolated mode. */
 	uint32_t mac:1; /**< Rule associated with a configured MAC address. */
 	uint32_t promisc:1; /**< This rule matches everything. */
+	uint32_t allmulti:1; /**< This rule matches all multicast traffic. */
 	uint32_t drop:1; /**< This rule drops packets. */
 	uint32_t queue:1; /**< Target is a receive queue. */
 	uint16_t queue_id; /**< Target queue. */
-- 
2.1.4