+/**
+ * Get metadata register index for specified steering domain.
+ *
+ * @param[in] dev
+ * Pointer to the rte_eth_dev structure.
+ * @param[in] attr
+ * Attributes of flow to determine steering domain.
+ * @param[out] error
+ * Pointer to the error structure.
+ *
+ * @return
+ * positive index on success, a negative errno value otherwise
+ * and rte_errno is set.
+ */
+static enum modify_reg
+flow_dv_get_metadata_reg(struct rte_eth_dev *dev,
+ const struct rte_flow_attr *attr,
+ struct rte_flow_error *error)
+{
+ enum modify_reg reg =
+ mlx5_flow_get_reg_id(dev, attr->transfer ?
+ MLX5_METADATA_FDB :
+ attr->egress ?
+ MLX5_METADATA_TX :
+ MLX5_METADATA_RX, 0, error);
+ if (reg < 0)
+ return rte_flow_error_set(error,
+ ENOTSUP, RTE_FLOW_ERROR_TYPE_ITEM,
+ NULL, "unavailable "
+ "metadata register");
+ return reg;
+}
+
+/**
+ * Convert SET_META action to DV specification.
+ *
+ * @param[in] dev
+ * Pointer to the rte_eth_dev structure.
+ * @param[in,out] resource
+ * Pointer to the modify-header resource.
+ * @param[in] attr
+ * Attributes of flow that includes this item.
+ * @param[in] conf
+ * Pointer to action specification.
+ * @param[out] error
+ * Pointer to the error structure.
+ *
+ * @return
+ * 0 on success, a negative errno value otherwise and rte_errno is set.
+ */
+static int
+flow_dv_convert_action_set_meta
+ (struct rte_eth_dev *dev,
+ struct mlx5_flow_dv_modify_hdr_resource *resource,
+ const struct rte_flow_attr *attr,
+ const struct rte_flow_action_set_meta *conf,
+ struct rte_flow_error *error)
+{
+ uint32_t data = conf->data;
+ uint32_t mask = conf->mask;
+ struct rte_flow_item item = {
+ .spec = &data,
+ .mask = &mask,
+ };
+ struct field_modify_info reg_c_x[] = {
+ [1] = {0, 0, 0},
+ };
+ enum modify_reg reg = flow_dv_get_metadata_reg(dev, attr, error);
+
+ if (reg < 0)
+ return reg;
+ /*
+ * In datapath code there is no endianness
+ * coversions for perfromance reasons, all
+ * pattern conversions are done in rte_flow.
+ */
+ if (reg == REG_C_0) {
+ struct mlx5_priv *priv = dev->data->dev_private;
+ uint32_t msk_c0 = priv->sh->dv_regc0_mask;
+ uint32_t shl_c0;
+
+ assert(msk_c0);
+#if RTE_BYTE_ORDER == RTE_BIG_ENDIAN
+ shl_c0 = rte_bsf32(msk_c0);
+#else
+ shl_c0 = sizeof(msk_c0) * CHAR_BIT - rte_fls_u32(msk_c0);
+#endif
+ mask <<= shl_c0;
+ data <<= shl_c0;
+ assert(!(~msk_c0 & rte_cpu_to_be_32(mask)));
+ }
+ reg_c_x[0] = (struct field_modify_info){4, 0, reg_to_field[reg]};
+ /* The routine expects parameters in memory as big-endian ones. */
+ return flow_dv_convert_modify_action(&item, reg_c_x, NULL, resource,
+ MLX5_MODIFICATION_TYPE_SET, error);
+}
+