[PATCH v1 1/2] net/mlx5: add limitation for E-Switch Manager match

[Shun Hao <shunh@nvidia.com>]

For BF with old FW which doesn't expose the E-Switch Manager vport ID,
E-Switch Manager port matching works correctly only when BF is in
embedded CPU mode.

This patch adds the limitation description.

Fixes: a564038699f9 ("net/mlx5: support E-Switch manager egress traffic match")
Cc: stable@dpdk.org

Signed-off-by: Shun Hao <shunh@nvidia.com>
Acked-by: Matan Azard <matan@nvidia.com>
---
 doc/guides/nics/mlx5.rst        |  4 ++++
 drivers/net/mlx5/mlx5_flow.h    |  4 ++++
 drivers/net/mlx5/mlx5_flow_dv.c | 10 ++++++++--
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index 1b66b2bc33..f10e112d27 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -534,6 +534,10 @@ Limitations
   - When configuring host shaper with MLX5_HOST_SHAPER_FLAG_AVAIL_THRESH_TRIGGERED flag set,
     only rates 0 and 100Mbps are supported.
 
+- E-Switch Manager matching:
+
+  - For Bluefield with old FW which doesn't expose the E-Switch Manager vport ID in the capability, matching E-Switch Manager should be used only in Bluefield embedded CPU mode.
+
 Statistics
 ----------
 
diff --git a/drivers/net/mlx5/mlx5_flow.h b/drivers/net/mlx5/mlx5_flow.h
index f00c033fc5..7300390070 100644
--- a/drivers/net/mlx5/mlx5_flow.h
+++ b/drivers/net/mlx5/mlx5_flow.h
@@ -2076,4 +2076,8 @@ int flow_dv_action_query(struct rte_eth_dev *dev,
 size_t flow_dv_get_item_hdr_len(const enum rte_flow_item_type item_type);
 int flow_dv_convert_encap_data(const struct rte_flow_item *items, uint8_t *buf,
 			   size_t *size, struct rte_flow_error *error);
+
+#define MLX5_PF_VPORT_ID 0
+#define MLX5_ECPF_VPORT_ID 0xFFFE
+
 #endif /* RTE_PMD_MLX5_FLOW_H_ */
diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index 65b02b20ce..09f662bdcf 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -99,6 +99,7 @@ flow_dv_get_esw_manager_vport_id(struct rte_eth_dev *dev)
 	struct mlx5_priv *priv = dev->data->dev_private;
 	struct mlx5_common_device *cdev = priv->sh->cdev;
 
+	/* New FW exposes E-Switch Manager vport ID, can use it directly. */
 	if (cdev->config.hca_attr.esw_mgr_vport_id_valid)
 		return (int16_t)cdev->config.hca_attr.esw_mgr_vport_id;
 
@@ -108,9 +109,14 @@ flow_dv_get_esw_manager_vport_id(struct rte_eth_dev *dev)
 	case PCI_DEVICE_ID_MELLANOX_CONNECTX5BF:
 	case PCI_DEVICE_ID_MELLANOX_CONNECTX6DXBF:
 	case PCI_DEVICE_ID_MELLANOX_CONNECTX7BF:
-		return (int16_t)0xfffe;
+	/*
+	 * In old FW which doesn't expose the E-Switch Manager vport ID in the capability,
+	 * only the BF embedded CPUs control the E-Switch Manager port. Hence,
+	 * ECPF vport ID is selected and not the host port (0) in any BF case.
+	 */
+		return (int16_t)MLX5_ECPF_VPORT_ID;
 	default:
-		return 0;
+		return MLX5_PF_VPORT_ID;
 	}
 }
 
-- 
2.20.0