patch 'net/mlx5: fix header modify action on group 0' has been queued to stable release 23.11.5

[Xueming Li]

Hi,

FYI, your patch has been queued to stable release 23.11.5

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 06/28/25. 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://git.dpdk.org/dpdk-stable/log/?h=23.11-staging

This queued commit can be viewed at:
https://git.dpdk.org/dpdk-stable/commit/?h=23.11-staging&id=5789022ac7b77a88a8805fff678cc2f572492956

Thanks.

Xueming Li <xuemingl at nvidia.com>

---
>From 5789022ac7b77a88a8805fff678cc2f572492956 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
Cc: Xueming Li <xuemingl at nvidia.com>

[ 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 c53d407746..fac6c51f90 100644
--- a/drivers/net/mlx5/mlx5_flow_hw.c
+++ b/drivers/net/mlx5/mlx5_flow_hw.c
@@ -1105,7 +1105,8 @@ 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 } };
 	struct mlx5_modification_cmd new_cmd = { { 0 } };
@@ -1113,6 +1114,15 @@ flow_hw_should_insert_nop(const struct mlx5_hw_modify_header_action *mhdr,
 	unsigned int last_type;
 	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;
 	last_cmd = *(&mhdr->mhdr_cmds[cmds_num - 1]);
@@ -1188,7 +1198,8 @@ 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;
 	int ret;
@@ -1196,7 +1207,7 @@ flow_hw_converted_mhdr_cmds_append(struct mlx5_hw_modify_header_action *mhdr,
 	for (idx = 0; idx < resource->actions_num; ++idx) {
 		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)
 				return ret;
@@ -1312,14 +1323,14 @@ flow_hw_modify_field_compile(struct rte_eth_dev *dev,
 	 * This NOP command will not be a part of action's command range used to update commands
 	 * 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)
 			return rte_flow_error_set(error, ret, RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
 						  NULL, "too many modify field operations specified");
 	}
 	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,
 					  NULL, "too many modify field operations specified");
-- 
2.34.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2025-06-26 19:59:18.707953789 +0800
+++ 0021-net-mlx5-fix-header-modify-action-on-group-0.patch	2025-06-26 19:59:17.246418050 +0800
@@ -1 +1 @@
-From f1ebb26d0d9388b6df65d493b06ce3b55adfb893 Mon Sep 17 00:00:00 2001
+From 5789022ac7b77a88a8805fff678cc2f572492956 Mon Sep 17 00:00:00 2001
@@ -4,0 +5,3 @@
+Cc: Xueming Li <xuemingl at nvidia.com>
+
+[ upstream commit f1ebb26d0d9388b6df65d493b06ce3b55adfb893 ]
@@ -22 +24,0 @@
-Cc: stable at dpdk.org
@@ -31 +33 @@
-index 2f7b769aec..cbe6bd3ef9 100644
+index c53d407746..fac6c51f90 100644
@@ -34 +36 @@
-@@ -1422,7 +1422,8 @@ flow_hw_action_modify_field_is_shared(const struct rte_flow_action *action,
+@@ -1105,7 +1105,8 @@ flow_hw_action_modify_field_is_shared(const struct rte_flow_action *action,
@@ -44 +46 @@
-@@ -1430,6 +1431,15 @@ flow_hw_should_insert_nop(const struct mlx5_hw_modify_header_action *mhdr,
+@@ -1113,6 +1114,15 @@ flow_hw_should_insert_nop(const struct mlx5_hw_modify_header_action *mhdr,
@@ -60 +62 @@
-@@ -1508,7 +1518,8 @@ flow_hw_mhdr_cmd_append(struct mlx5_hw_modify_header_action *mhdr,
+@@ -1188,7 +1198,8 @@ flow_hw_mhdr_cmd_append(struct mlx5_hw_modify_header_action *mhdr,
@@ -70 +72 @@
-@@ -1516,7 +1527,7 @@ flow_hw_converted_mhdr_cmds_append(struct mlx5_hw_modify_header_action *mhdr,
+@@ -1196,7 +1207,7 @@ flow_hw_converted_mhdr_cmds_append(struct mlx5_hw_modify_header_action *mhdr,
@@ -79 +81 @@
-@@ -1639,14 +1650,14 @@ flow_hw_modify_field_compile(struct rte_eth_dev *dev,
+@@ -1312,14 +1323,14 @@ flow_hw_modify_field_compile(struct rte_eth_dev *dev,