[PATCH 2/2] net/mlx5: add modify field actions number validation

[Dariusz Sosnowski <dsosnowski@nvidia.com>]

This patch adds validation for the number of modify field actions,
when working with HW Steering.

If translation of modify field actions generated more HW commands
than supported by the FW, then proper error is returned.
Additionally, number of generated commands is logged,
along with a number of NOP commands added.
This validation is only valid for HWS template tables, in groups > 0.

Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
---
 drivers/net/mlx5/mlx5_flow_hw.c | 51 +++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/drivers/net/mlx5/mlx5_flow_hw.c b/drivers/net/mlx5/mlx5_flow_hw.c
index 7e0ee8d883..0a7416c7a1 100644
--- a/drivers/net/mlx5/mlx5_flow_hw.c
+++ b/drivers/net/mlx5/mlx5_flow_hw.c
@@ -1086,6 +1086,53 @@ flow_hw_modify_field_compile(struct rte_eth_dev *dev,
 	return 0;
 }
 
+static uint32_t
+flow_hw_count_nop_modify_field(struct mlx5_hw_modify_header_action *mhdr)
+{
+	uint32_t i;
+	uint32_t nops = 0;
+
+	for (i = 0; i < mhdr->mhdr_cmds_num; ++i) {
+		struct mlx5_modification_cmd cmd = mhdr->mhdr_cmds[i];
+
+		cmd.data0 = rte_be_to_cpu_32(cmd.data0);
+		if (cmd.action_type == MLX5_MODIFICATION_TYPE_NOP)
+			++nops;
+	}
+	return nops;
+}
+
+static int
+flow_hw_validate_compiled_modify_field(struct rte_eth_dev *dev,
+				       const struct mlx5_flow_template_table_cfg *cfg,
+				       struct mlx5_hw_modify_header_action *mhdr,
+				       struct rte_flow_error *error)
+{
+	struct mlx5_priv *priv = dev->data->dev_private;
+	struct mlx5_hca_attr *hca_attr = &priv->sh->cdev->config.hca_attr;
+
+	/*
+	 * Header modify pattern length limitation is only valid for HWS groups, i.e. groups > 0.
+	 * In group 0, MODIFY_FIELD actions are handled with header modify actions
+	 * managed by rdma-core.
+	 */
+	if (cfg->attr.flow_attr.group != 0 &&
+	    mhdr->mhdr_cmds_num > hca_attr->max_header_modify_pattern_length) {
+		uint32_t nops = flow_hw_count_nop_modify_field(mhdr);
+
+		DRV_LOG(ERR, "Too many modify header commands generated from "
+			     "MODIFY_FIELD actions. "
+			     "Generated HW commands = %u (amount of NOP commands = %u). "
+			     "Maximum supported = %u.",
+			     mhdr->mhdr_cmds_num, nops,
+			     hca_attr->max_header_modify_pattern_length);
+		return rte_flow_error_set(error, EINVAL, RTE_FLOW_ERROR_TYPE_ACTION, NULL,
+					  "Number of MODIFY_FIELD actions exceeds maximum "
+					  "supported limit of actions");
+	}
+	return 0;
+}
+
 static int
 flow_hw_represented_port_compile(struct rte_eth_dev *dev,
 				 const struct rte_flow_attr *attr,
@@ -1704,6 +1751,10 @@ __flow_hw_actions_translate(struct rte_eth_dev *dev,
 		uint32_t bulk_size;
 		size_t mhdr_len;
 
+		if (flow_hw_validate_compiled_modify_field(dev, cfg, &mhdr, error)) {
+			__flow_hw_action_template_destroy(dev, acts);
+			return -rte_errno;
+		}
 		acts->mhdr = mlx5_malloc(MLX5_MEM_ZERO, sizeof(*acts->mhdr),
 					 0, SOCKET_ID_ANY);
 		if (!acts->mhdr)
-- 
2.25.1