Looks like a bug: operands are different enum types 'ibv_flow_attr_type' and 'ibv_flow_flags'

Andre Muezerie andremue at linux.microsoft.com
Tue May 27 21:32:56 CEST 2025


Hi Folks,


Compiling with MSCS resulted in the warning below:

../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

It looks like a legit bug. Here is the offending line:

	struct mlx5dv_flow_matcher_attr dv_attr = {
		.type = IBV_FLOW_ATTR_NORMAL | IBV_FLOW_ATTR_FLAGS_EGRESS,

As the warning states, the constants in the bitwise operation belong to different enums, and these enums have overlaping values, which makes the bitwise operation very suspicious.
On top of that, I see that struct mlx5dv_flow_matcher_attr has a field named "flags" which accepts values from ibv_flow_flags:

	struct mlx5dv_flow_matcher_attr {
		enum ibv_flow_attr_type type;
		uint32_t flags; /* From enum ibv_flow_flags. */

Could someone more familiar with the code take a look and make a fix if needed? My goal here is just to get the code to compile with MSVC without warnings. I can add a cast to remove the warning if this is indeed how the code should be, but I don't want to do this unless I get confirmation that this would be the right course of action.

Thanks,

Andre Muezerie


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