Re: [PATCH net-next] net/mlx5: Add MLX5_VXLAN config option

[Gal Pressman <gal@nvidia.com>]

On 13/05/2026 19:20, Marc Harvey wrote:
> On Tue, May 5, 2026 at 1:21 AM Gal Pressman <gal@nvidia.com> wrote:
>>
>> Hi Marc,
>>
>> On 05/05/2026 4:10, Jakub Kicinski wrote:
>>>
>>> Sorry, I don't know mlx5 very well. Sounds like you have to talk
>>> to nVidia or/and run some experiments. The current patch is a no-go.
>>>
>>
>> The hardware offloads 4789 by default, hence the
>> UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN, you cannot simply remove it.
>>
>> Have you tried disabling tx-udp_tnl-segmentation through ethtool?
> 
> Thanks for the responses.
> 
> Gal, by "the hardware offloads 4789 by default," does that mean the
> hardware offloads 4789 even without an explicit command from the
> driver? I ask because mlx5 does send a command to offload 4789, but
> perhaps this command is redundant and only for bookkeeping purposes.

Yes, we add the port so features_check flow would see this port is
offloaded.

> 
> I haven't tried changing the offload related ethtool parameters, and I
> will, but I suspect it won't help in this specific case since the
> perceived regression involved non-tunneled traffic.

What is the purpose of this patch then?

> 
> If the hardware indeed offloads 4789 autonomously, then the perceived
> regression we saw might not have been real or related to enabling
> vxlan.

Can you elaborate more on the regression?
What is the issue? When did is start happening?

Maybe you're experiencing this?
https://lore.kernel.org/all/6c3fb15e-711d-4b8d-b152-e03d9b05293f@linux.dev/