Re: [V1] app/testpmd: restore VXLAN-GPE support

[Ferruh Yigit <ferruh.yigit@amd.com>]

On 7/22/2024 2:04 PM, Thomas Monjalon wrote:
> 22/07/2024 11:36, Ferruh Yigit:
>> On 7/22/2024 8:10 AM, Minggang(Gavin) Li wrote:
>>> From: Ferruh Yigit <ferruh.yigit@amd.com>
>>>> On 7/17/2024 8:11 AM, Gavin Li wrote:
>>>>> VXLAN-GPE support was removed from testpmd recently. Drivers which are
>>>>> not migrated are still using VXLAN-GPE in tests.
>>>>>
>>>>> This commit is to restore the support for VXLAN-GPE in testpmd.
>>>>>
>>>>> Fixes: da118115d95c ("app/testpmd: support matching any VXLAN field")
>>>>> Signed-off-by: Gavin Li <gavinl@nvidia.com>
>>>>>
>>>>
>>>> Hi Gavin,
>>>>
>>>> The original patch was from you, right? What went wrong?
>>> The remove of VXLAN-GPE from testpmd is too aggressive since there are
>>> drivers which are not migrated are still using VXLAN-GPE. It's better to
>>> keep it till the day to remove the RTE item of VXLAN-GPE from DPDK.
>>>
>>
>> Sorry, I was not clear enough maybe, I was asking more details on the
>> problem?
> 
> I remember I was suggesting Gavin to remove testpmd code based on the old API.
> And he realized it was too much agressive later.
> 
>> With a net/vxlan commit [1] in this release, (this commit is part of
>> -rc1), VXLAN & VXLAN-GPE headers combined and VXLAN-GBP header added to
>> this combined struct. VXLAN-GPE header is marked as deprecated.
>> Testpmd is also updated to use new headers, that is the commit in the
>> fixes tag of this patch.
>>
>> But drivers using old, now depreciated, VXLAN structs won't able to use
>> testpmd to test, so I agree, may be I merged the patch too early.
> 
> Yes, so this patch re-add testpmd code for the old API.
> 
>> As this patch was part of -rc1, I wonder why we didn't get any complaint
>> about not able to test VXLAN-GPE?
> 
> Maybe it is tested only with mlx5.
> 
>> Btw, if we revert this patch, is there a way to test VXLAN-GBP? Because
>> it only exists as part of new combined VXLAN struct?
>> Instead of reverting the commit all together, is there way to keep old
>> capability in testpmd, but add feature to test VXLAN-GBP?
> 
> It is not a complete revert, we keep GBP in the new API.
> 

So what I was asking done already, let me check the patch again.

>> And another issue is, there can still some users of the VXLAN-GPE header
>> in the net library, perhaps that also deprecated immaturely.
> 
> It is just marked as deprecated.
> 
>> Can you please send a deprecation note for combining VXLAN headers and
>> removing VXLAN-GPE in v24.11? Please CC all drivers implementing this
>> flow pattern. This can be way to highlight the issue to driver
>> maintainers and communicate the change with end users.
> 
> 24.11 is probably too early.
> I propose to keep it as deprecated for compatibility,
> and maybe remove in one year?
> 

No strong opinion, both v24.11 or v25.11 is OK.

Normally I would go with v25.11, but for VXLAN I expect only small users
will be impacted and only a few driver needs update, so perhaps v24.11
also can be a valid target.
We can get comment from driver maintainers to the deprecation notice,
but not able to get this from potential users.