[v2 2/3] net/mlx5: add support to modify ECN field

[Sean Zhang <xiazhang@nvidia.com>]

This patch is to support modify ECN field in IPv4/IPv6 header.

Signed-off-by: Sean Zhang <xiazhang@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
---
 doc/guides/nics/mlx5.rst               |  1 +
 doc/guides/rel_notes/release_22_07.rst |  1 +
 drivers/net/mlx5/mlx5_flow_dv.c        | 20 ++++++++++++++++++++
 3 files changed, 22 insertions(+)

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index d83c56d..7ecf11e 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -93,6 +93,7 @@ Features
 - Connection tracking.
 - Sub-Function representors.
 - Sub-Function.
+- Modify IPv4/IPv6 ECN field.
 
 
 Limitations
diff --git a/doc/guides/rel_notes/release_22_07.rst b/doc/guides/rel_notes/release_22_07.rst
index d46f773..a2a8cf0 100644
--- a/doc/guides/rel_notes/release_22_07.rst
+++ b/doc/guides/rel_notes/release_22_07.rst
@@ -116,6 +116,7 @@ New Features
   * Added support for promiscuous mode on Windows.
   * Added support for MTU on Windows.
   * Added matching and RSS on IPsec ESP.
+  * Added support for modifying ECN field of IPv4/IPv6.
 
 * **Updated VMware vmxnet3 networking driver.**
 
diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index a575e31..0f028de 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -1450,6 +1450,9 @@ struct field_modify_info modify_tcp[] = {
 	case RTE_FLOW_FIELD_POINTER:
 	case RTE_FLOW_FIELD_VALUE:
 		return inherit < 0 ? 0 : inherit;
+	case RTE_FLOW_FIELD_IPV4_ECN:
+	case RTE_FLOW_FIELD_IPV6_ECN:
+		return 2;
 	default:
 		MLX5_ASSERT(false);
 	}
@@ -1827,6 +1830,13 @@ struct field_modify_info modify_tcp[] = {
 					(meta_count - width)) & meta_mask);
 		}
 		break;
+	case RTE_FLOW_FIELD_IPV4_ECN:
+	case RTE_FLOW_FIELD_IPV6_ECN:
+		info[idx] = (struct field_modify_info){1, 0,
+					MLX5_MODI_OUT_IP_ECN};
+		if (mask)
+			mask[idx] = 0x3 >> (2 - width);
+		break;
 	case RTE_FLOW_FIELD_POINTER:
 	case RTE_FLOW_FIELD_VALUE:
 	default:
@@ -4826,6 +4836,7 @@ struct mlx5_list_entry *
 	int ret = 0;
 	struct mlx5_priv *priv = dev->data->dev_private;
 	struct mlx5_sh_config *config = &priv->sh->config;
+	struct mlx5_hca_attr *hca_attr = &priv->sh->cdev->config.hca_attr;
 	const struct rte_flow_action_modify_field *action_modify_field =
 		action->conf;
 	uint32_t dst_width = mlx5_flow_item_field_width(dev,
@@ -4953,6 +4964,15 @@ struct mlx5_list_entry *
 				RTE_FLOW_ERROR_TYPE_ACTION, action,
 				"add and sub operations"
 				" are not supported");
+	if (action_modify_field->dst.field == RTE_FLOW_FIELD_IPV4_ECN ||
+	    action_modify_field->src.field == RTE_FLOW_FIELD_IPV4_ECN ||
+	    action_modify_field->dst.field == RTE_FLOW_FIELD_IPV6_ECN ||
+	    action_modify_field->src.field == RTE_FLOW_FIELD_IPV6_ECN)
+		if (!hca_attr->modify_outer_ip_ecn &&
+		    !attr->transfer && !attr->group)
+			return rte_flow_error_set(error, ENOTSUP,
+				RTE_FLOW_ERROR_TYPE_ACTION, action,
+				"modifications of the ECN for current firmware is not supported");
 	return (action_modify_field->width / 32) +
 	       !!(action_modify_field->width % 32);
 }
-- 
1.8.3.1