Re: [PATCH] net/mlx5: deprecate representor matching devarg

[Adrian Schollmeyer <a.schollmeyer@syseleven.de>]

Hi,

On 16.07.25 11:38, Dariusz Sosnowski wrote:

> Mark repr_matching_en device argument exposed by mlx5 PMD
> as deprecated and schedule its removal in 25.11 release.
>
> [...]
>
> A new unified representor model, described in
> https://fast.dpdk.org/events/slides/DPDK-2024-07-unified_representor.pdf
> should be developed.

The unified representor model seems to only address aggregation of 
traffic of all ports to a single representor (the e-switch manager port).
In our use case with BlueField DPUs, however, traffic is always 
intercepted by the DPU and handled differently depending on whether the 
traffic came from one of the host representors (i.e. the host system or 
a VM) or one of the physical port representors (i.e. the the network 
fabric).
These two traffic groups are usually processed by disjoint sets of CPUs 
processing disjoint sets of DPDK ports.
With repr_matching_en=0, we can flexibly steer traffic from many 
represented ports to different representors (e.g. dummy SF representors) 
to aggregate traffic by port group on the receive path.
To do this, we create flow rules that tag packets received from the 
represented ports accordingly and match traffic by this tag in ingress 
flow rules for the aggregation representors. This is only possible with 
repr_matching_en=0, since only then traffic coming from arbitrary ports 
can be matched.

Hence my question: Can such a flexible mapping still be achieved without 
repr_matching_en=0? Otherwise, removal of this devarg would break our 
use case.

Best regards
Adrian

-- 

Adrian Schollmeyer

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