[PATCH] net/mlx5: fix matcher flags in counter offset detection

[PATCH] net/mlx5: fix matcher flags in counter offset detection

[Dariusz Sosnowski]

This patch fixes a bug in
mlx5_flow_dv_discover_counter_offset_support()
uncovered by a warning reported by MSVC:

    ../drivers/net/mlx5/mlx5_flow_dv.c(19636): warning C5287:
        operands are different enum types 'ibv_flow_attr_type' and
        'ibv_flow_flags';
        use an explicit cast to silence this warning

IBV_FLOW_ATTR_FLAGS_EGRESS was incorrectly passed in to
type field of mlx5dv_flow_matcher_attr struct,
instead of flags field.
As a result counter offset support discovery returned a false positive
result on application with old rdma-core.

Bugzilla ID: 1758
Fixes: 4fd5e1484887 ("net/mlx5: fix counter offset detection")
Cc: suanmingm@nvidia.com
Cc: stable@dpdk.org

Reported-by: Andre Muezerie <andremue@linux.microsoft.com>
Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
---
 drivers/net/mlx5/mlx5_flow_dv.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index 7b9e5018b8..4a6f9d63fb 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -19652,7 +19652,8 @@ mlx5_flow_dv_discover_counter_offset_support(struct rte_eth_dev *dev)
 		.size = sizeof(value.buf),
 	};
 	struct mlx5dv_flow_matcher_attr dv_attr = {
-		.type = IBV_FLOW_ATTR_NORMAL | IBV_FLOW_ATTR_FLAGS_EGRESS,
+		.type = IBV_FLOW_ATTR_NORMAL,
+		.flags = IBV_FLOW_ATTR_FLAGS_EGRESS,
 		.priority = 0,
 		.match_criteria_enable = 0,
 		.match_mask = (void *)&mask,
--
2.39.5

Re: [PATCH] net/mlx5: fix matcher flags in counter offset detection

[David Marchand]

On Wed, 20 Aug 2025 at 10:47, Dariusz Sosnowski <dsosnowski@nvidia.com> wrote:
>
> This patch fixes a bug in
> mlx5_flow_dv_discover_counter_offset_support()
> uncovered by a warning reported by MSVC:
>
>     ../drivers/net/mlx5/mlx5_flow_dv.c(19636): warning C5287:
>         operands are different enum types 'ibv_flow_attr_type' and
>         'ibv_flow_flags';
>         use an explicit cast to silence this warning
>
> IBV_FLOW_ATTR_FLAGS_EGRESS was incorrectly passed in to
> type field of mlx5dv_flow_matcher_attr struct,
> instead of flags field.
> As a result counter offset support discovery returned a false positive
> result on application with old rdma-core.
>
> Bugzilla ID: 1758
> Fixes: 4fd5e1484887 ("net/mlx5: fix counter offset detection")
> Cc: suanmingm@nvidia.com
> Cc: stable@dpdk.org
>
> Reported-by: Andre Muezerie <andremue@linux.microsoft.com>
> Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>

I did not test the patch, but on the principle this lgtm.

Andre, can you confirm it solves the build warning you were seeing with MSVC?


-- 
David Marchand

Re: [PATCH] net/mlx5: fix matcher flags in counter offset detection

[Andre Muezerie]

On Wed, Aug 27, 2025 at 11:15:57AM +0200, David Marchand wrote:
> On Wed, 20 Aug 2025 at 10:47, Dariusz Sosnowski <dsosnowski@nvidia.com> wrote:
> >
> > This patch fixes a bug in
> > mlx5_flow_dv_discover_counter_offset_support()
> > uncovered by a warning reported by MSVC:
> >
> >     ../drivers/net/mlx5/mlx5_flow_dv.c(19636): warning C5287:
> >         operands are different enum types 'ibv_flow_attr_type' and
> >         'ibv_flow_flags';
> >         use an explicit cast to silence this warning
> >
> > IBV_FLOW_ATTR_FLAGS_EGRESS was incorrectly passed in to
> > type field of mlx5dv_flow_matcher_attr struct,
> > instead of flags field.
> > As a result counter offset support discovery returned a false positive
> > result on application with old rdma-core.
> >
> > Bugzilla ID: 1758
> > Fixes: 4fd5e1484887 ("net/mlx5: fix counter offset detection")
> > Cc: suanmingm@nvidia.com
> > Cc: stable@dpdk.org
> >
> > Reported-by: Andre Muezerie <andremue@linux.microsoft.com>
> > Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
> 
> I did not test the patch, but on the principle this lgtm.
> 
> Andre, can you confirm it solves the build warning you were seeing with MSVC?
> 
> 
> -- 
> David Marchand
> 

Dariusz and David,

This patch compiles cleanly with MSVC.
Thanks for fixing this bug!

Andre Muezerie

Re: [PATCH] net/mlx5: fix matcher flags in counter offset detection

[Andre Muezerie]

On Wed, Aug 20, 2025 at 10:45:21AM +0200, Dariusz Sosnowski wrote:
> This patch fixes a bug in
> mlx5_flow_dv_discover_counter_offset_support()
> uncovered by a warning reported by MSVC:
> 
>     ../drivers/net/mlx5/mlx5_flow_dv.c(19636): warning C5287:
>         operands are different enum types 'ibv_flow_attr_type' and
>         'ibv_flow_flags';
>         use an explicit cast to silence this warning
> 
> IBV_FLOW_ATTR_FLAGS_EGRESS was incorrectly passed in to
> type field of mlx5dv_flow_matcher_attr struct,
> instead of flags field.
> As a result counter offset support discovery returned a false positive
> result on application with old rdma-core.
> 
> Bugzilla ID: 1758
> Fixes: 4fd5e1484887 ("net/mlx5: fix counter offset detection")
> Cc: suanmingm@nvidia.com
> Cc: stable@dpdk.org
> 
> Reported-by: Andre Muezerie <andremue@linux.microsoft.com>
> Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
> ---
>  drivers/net/mlx5/mlx5_flow_dv.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
> index 7b9e5018b8..4a6f9d63fb 100644
> --- a/drivers/net/mlx5/mlx5_flow_dv.c
> +++ b/drivers/net/mlx5/mlx5_flow_dv.c
> @@ -19652,7 +19652,8 @@ mlx5_flow_dv_discover_counter_offset_support(struct rte_eth_dev *dev)
>  		.size = sizeof(value.buf),
>  	};
>  	struct mlx5dv_flow_matcher_attr dv_attr = {
> -		.type = IBV_FLOW_ATTR_NORMAL | IBV_FLOW_ATTR_FLAGS_EGRESS,
> +		.type = IBV_FLOW_ATTR_NORMAL,
> +		.flags = IBV_FLOW_ATTR_FLAGS_EGRESS,
>  		.priority = 0,
>  		.match_criteria_enable = 0,
>  		.match_mask = (void *)&mask,
> --
> 2.39.5
> 

This compiles cleanly with msvc. Thanks for fixing it.

Acked-by: Andre Muezerie <andremue@linux.microsoft.com>