[dpdk-dev] [PATCH v3 5/7] net/mlx5: support modify VLAN priority on VLAN hdr

[Moti Haimovsky <motih@mellanox.com>]

This commit adds support for modifying the VLAN priority (PCP) field
in about-to-be-pushed VLAN header.
This feature can only modify the PCP field of a new VLAN header yet
to be pushed. It does not support modifying an existing or already
pushed VLAN headers.

Signed-off-by: Moti Haimovsky <motih@mellanox.com>
---
 doc/guides/nics/mlx5.rst        |  5 +++-
 drivers/net/mlx5/mlx5_flow_dv.c | 58 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index 21c9de7..acaefd0 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -128,6 +128,8 @@ Limitations
 
 - VLAN push offload is not supported on ingress traffic.
 
+- VLAN set PCP offload is not supported on existing headers.
+
 - A multi segment packet must have not more segments than reported by dev_infos_get()
   in tx_desc_lim.nb_seg_max field. This value depends on maximal supported Tx descriptor
   size and ``txq_inline_min`` settings and may be from 2 (worst case forced by maximal
@@ -1038,7 +1040,8 @@ Supported hardware offloads
    +-----------------------+-----------------+-----------------+
    | | VLAN                | | DPDK 19.11    | | DPDK 19.11    |
    | | (of_pop_vlan /      | | OFED 4.6-4    | | OFED 4.6-4    |
-   | | of_push_vlan)       | | ConnectX-5    | | ConnectX-5    |
+   | | of_push_vlan /      | | ConnectX-5    | | ConnectX-5    |
+   | | of_set_vlan_pcp)    |                 |                 |
    +-----------------------+-----------------+-----------------+
 
 Notes for testpmd
diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index 3a92846..30b0112 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -967,6 +967,47 @@ struct field_modify_info modify_tcp[] = {
 }
 
 /**
+ * Validate the set VLAN PCP.
+ *
+ * @param[in] action_flags
+ *   Holds the actions detected until now.
+ * @param[in] actions
+ *   Pointer to the list of actions remaining in the flow rule.
+ * @param[in] attr
+ *   Pointer to flow attributes
+ * @param[out] error
+ *   Pointer to error structure.
+ *
+ * @return
+ *   0 on success, a negative errno value otherwise and rte_errno is set.
+ */
+static int
+flow_dv_validate_action_set_vlan_pcp(uint64_t action_flags,
+				     const struct rte_flow_action actions[],
+				     struct rte_flow_error *error)
+{
+	const struct rte_flow_action *action = actions;
+	const struct rte_flow_action_of_set_vlan_pcp *conf = action->conf;
+
+	if (conf->vlan_pcp > 7)
+		return rte_flow_error_set(error, EINVAL,
+					  RTE_FLOW_ERROR_TYPE_ACTION, action,
+					  "VLAN PCP value to too big");
+	if (mlx5_flow_find_action(actions,
+				  RTE_FLOW_ACTION_TYPE_OF_PUSH_VLAN) == NULL)
+		return rte_flow_error_set(error, ENOTSUP,
+					  RTE_FLOW_ERROR_TYPE_ACTION, action,
+					  "set VLAN PCP can only be used "
+					  "with push VLAN action");
+	if (action_flags & MLX5_FLOW_ACTION_OF_PUSH_VLAN)
+		return rte_flow_error_set(error, ENOTSUP,
+					  RTE_FLOW_ERROR_TYPE_ACTION, action,
+					  "set VLAN PCP action must precede "
+					  "the push VLAN action");
+	return 0;
+}
+
+/**
  * Validate count action.
  *
  * @param[in] dev
@@ -3383,6 +3424,13 @@ struct field_modify_info modify_tcp[] = {
 			action_flags |= MLX5_FLOW_ACTION_OF_PUSH_VLAN;
 			++actions_n;
 			break;
+		case RTE_FLOW_ACTION_TYPE_OF_SET_VLAN_PCP:
+			ret = flow_dv_validate_action_set_vlan_pcp
+						(action_flags, actions, error);
+			if (ret < 0)
+				return ret;
+			/* Count PCP with push_vlan command. */
+			break;
 		case RTE_FLOW_ACTION_TYPE_VXLAN_ENCAP:
 		case RTE_FLOW_ACTION_TYPE_NVGRE_ENCAP:
 			ret = flow_dv_validate_action_l2_encap(action_flags,
@@ -4973,6 +5021,7 @@ struct field_modify_info modify_tcp[] = {
 	void *match_mask = matcher.mask.buf;
 	void *match_value = dev_flow->dv.value.buf;
 	uint8_t next_protocol = 0xff;
+	uint16_t vlan_tci;
 	struct flow_dv_vlan_be vlan = { 0 };
 
 	flow_dev_get_vlan_info_from_items(items, &vlan);
@@ -5100,6 +5149,15 @@ struct field_modify_info modify_tcp[] = {
 					   dev_flow->dv.push_vlan_res->action;
 			action_flags |= MLX5_FLOW_ACTION_OF_PUSH_VLAN;
 			break;
+		case RTE_FLOW_ACTION_TYPE_OF_SET_VLAN_PCP:
+			vlan_tci =
+			    ((const struct rte_flow_action_of_set_vlan_pcp *)
+						       actions->conf)->vlan_pcp;
+			vlan_tci = vlan_tci << FLOW_DV_VLAN_PCP_SHIFT;
+			vlan.tci &= ~FLOW_DV_VLAN_PCP_MASK;
+			vlan.tci |= rte_cpu_to_be_16(vlan_tci);
+			/* Push VLAN command will use this value */
+			break;
 		case RTE_FLOW_ACTION_TYPE_VXLAN_ENCAP:
 		case RTE_FLOW_ACTION_TYPE_NVGRE_ENCAP:
 			if (flow_dv_create_action_l2_encap(dev, actions,
-- 
1.8.3.1