patch 'net/mlx5: fix header modify action on group 0' has been queued to stable release 24.11.3

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 24.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 07/23/25. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/9057144d8b207d0f88115d16378a30a3757d7b7c

Thanks.

Kevin

---
>From 9057144d8b207d0f88115d16378a30a3757d7b7c Mon Sep 17 00:00:00 2001
From: Dariusz Sosnowski <dsosnowski at nvidia.com>
Date: Fri, 25 Apr 2025 21:32:57 +0200
Subject: [PATCH] net/mlx5: fix header modify action on group 0

[ upstream commit f1ebb26d0d9388b6df65d493b06ce3b55adfb893 ]

HW modify header commands generated for multiple modify field
flow actions, which modify/access the same packet fields
do not have to be separated by NOPs when used on group 0.
This is because:

- On group > 0, HW uses Modify Header Pattern objects
  which require NOP explicitly.
- On group 0, modify field action is implemented using
  Modify Header Context object managed by FW.
  FW inserts requires NOPs internally.

mlx5 PMD inserted NOP always, which caused flow/table creation
failures on group 0 flow rules.
This patch addresses that.

Fixes: 0f4aa72b99da ("net/mlx5: support flow modify field with HWS")

Signed-off-by: Dariusz Sosnowski <dsosnowski at nvidia.com>
Acked-by: Bing Zhao <bingz at nvidia.com>
---
 drivers/net/mlx5/mlx5_flow_hw.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_flow_hw.c b/drivers/net/mlx5/mlx5_flow_hw.c
index 5601abf90d..3d04d86911 100644
--- a/drivers/net/mlx5/mlx5_flow_hw.c
+++ b/drivers/net/mlx5/mlx5_flow_hw.c
@@ -1377,5 +1377,6 @@ flow_hw_action_modify_field_is_shared(const struct rte_flow_action *action,
 static __rte_always_inline bool
 flow_hw_should_insert_nop(const struct mlx5_hw_modify_header_action *mhdr,
-			  const struct mlx5_modification_cmd *cmd)
+			  const struct mlx5_modification_cmd *cmd,
+			  const struct rte_flow_attr *attr)
 {
 	struct mlx5_modification_cmd last_cmd = { { 0 } };
@@ -1385,4 +1386,13 @@ flow_hw_should_insert_nop(const struct mlx5_hw_modify_header_action *mhdr,
 	bool should_insert = false;
 
+	/*
+	 * Modify header action list does not require NOPs in root table,
+	 * because different type of underlying object is used:
+	 * - in root table - MODIFY_HEADER_CONTEXT (does not require NOPs),
+	 * - in non-root - either inline modify action or based on Modify Header Pattern
+	 *   (which requires NOPs).
+	 */
+	if (attr->group == 0)
+		return false;
 	if (cmds_num == 0)
 		return false;
@@ -1463,5 +1473,6 @@ flow_hw_mhdr_cmd_append(struct mlx5_hw_modify_header_action *mhdr,
 static __rte_always_inline int
 flow_hw_converted_mhdr_cmds_append(struct mlx5_hw_modify_header_action *mhdr,
-				   struct mlx5_flow_dv_modify_hdr_resource *resource)
+				   struct mlx5_flow_dv_modify_hdr_resource *resource,
+				   const struct rte_flow_attr *attr)
 {
 	uint32_t idx;
@@ -1471,5 +1482,5 @@ flow_hw_converted_mhdr_cmds_append(struct mlx5_hw_modify_header_action *mhdr,
 		struct mlx5_modification_cmd *src = &resource->actions[idx];
 
-		if (flow_hw_should_insert_nop(mhdr, src)) {
+		if (flow_hw_should_insert_nop(mhdr, src, attr)) {
 			ret = flow_hw_mhdr_cmd_nop_append(mhdr);
 			if (ret)
@@ -1594,5 +1605,5 @@ flow_hw_modify_field_compile(struct rte_eth_dev *dev,
 	 * on rule creation.
 	 */
-	if (flow_hw_should_insert_nop(mhdr, &resource->actions[0])) {
+	if (flow_hw_should_insert_nop(mhdr, &resource->actions[0], attr)) {
 		ret = flow_hw_mhdr_cmd_nop_append(mhdr);
 		if (ret)
@@ -1601,5 +1612,5 @@ flow_hw_modify_field_compile(struct rte_eth_dev *dev,
 	}
 	cmds_start = mhdr->mhdr_cmds_num;
-	ret = flow_hw_converted_mhdr_cmds_append(mhdr, resource);
+	ret = flow_hw_converted_mhdr_cmds_append(mhdr, resource, attr);
 	if (ret)
 		return rte_flow_error_set(error, ret, RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-- 
2.50.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2025-07-18 20:29:11.918484998 +0100
+++ 0024-net-mlx5-fix-header-modify-action-on-group-0.patch	2025-07-18 20:29:10.836907043 +0100
@@ -1 +1 @@
-From f1ebb26d0d9388b6df65d493b06ce3b55adfb893 Mon Sep 17 00:00:00 2001
+From 9057144d8b207d0f88115d16378a30a3757d7b7c Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit f1ebb26d0d9388b6df65d493b06ce3b55adfb893 ]
+
@@ -22 +23,0 @@
-Cc: stable at dpdk.org
@@ -31 +32 @@
-index 2f7b769aec..cbe6bd3ef9 100644
+index 5601abf90d..3d04d86911 100644
@@ -34 +35 @@
-@@ -1423,5 +1423,6 @@ flow_hw_action_modify_field_is_shared(const struct rte_flow_action *action,
+@@ -1377,5 +1377,6 @@ flow_hw_action_modify_field_is_shared(const struct rte_flow_action *action,
@@ -42 +43 @@
-@@ -1431,4 +1432,13 @@ flow_hw_should_insert_nop(const struct mlx5_hw_modify_header_action *mhdr,
+@@ -1385,4 +1386,13 @@ flow_hw_should_insert_nop(const struct mlx5_hw_modify_header_action *mhdr,
@@ -56 +57 @@
-@@ -1509,5 +1519,6 @@ flow_hw_mhdr_cmd_append(struct mlx5_hw_modify_header_action *mhdr,
+@@ -1463,5 +1473,6 @@ flow_hw_mhdr_cmd_append(struct mlx5_hw_modify_header_action *mhdr,
@@ -64 +65 @@
-@@ -1517,5 +1528,5 @@ flow_hw_converted_mhdr_cmds_append(struct mlx5_hw_modify_header_action *mhdr,
+@@ -1471,5 +1482,5 @@ flow_hw_converted_mhdr_cmds_append(struct mlx5_hw_modify_header_action *mhdr,
@@ -71 +72 @@
-@@ -1640,5 +1651,5 @@ flow_hw_modify_field_compile(struct rte_eth_dev *dev,
+@@ -1594,5 +1605,5 @@ flow_hw_modify_field_compile(struct rte_eth_dev *dev,
@@ -78 +79 @@
-@@ -1647,5 +1658,5 @@ flow_hw_modify_field_compile(struct rte_eth_dev *dev,
+@@ -1601,5 +1612,5 @@ flow_hw_modify_field_compile(struct rte_eth_dev *dev,