Re: [PATCH net-next 0/3] seg6_local: add USP and USD flavors support (RFC 8986)

[Hangbin Liu <hangbin.liu@linux.dev>]

Hi Minhong,
On Tue, Nov 03, 2026 at 02:38:03PM +0800, Minhong He wrote:
> RFC 8986 defines the PSP, USP and USD flavors for the SRv6 End
> behaviors. Currently, the Linux SRv6 implementation (seg6_local)
> only supports the PSP flavor (combined with the NEXT-C-SID
> flavor).

No, the kernel will not process PSP when it is combined with
NEXT-C-SID at present.

> 
> This patch series adds support for the USP (Ultimate Segment Pop
> of the SRH) flavor to the End, End.X and End.T behaviors, and for
> the USD (Ultimate Segment Decapsulation) flavor to the SRv6 End
> behaviors that perform the decapsulation of the packet (i.e.,
> End.DX4, End.DX6, End.DT4, End.DT6, End.DT46).

Thanks for the patch. Unfortunately, I have already started this work back
in September. I discussed my plan with Andrea at that time. Sadly, I did not
mention this in the cover letter for my PSP support series[1], that’s my mistake.
I didn’t expect someone would skip PSP and start with USP/USD directly.

Kernel changes alone are not sufficient, we also need selftest updates for
this new feature. So I’ve begun adding PSP support for End.X, along with the
corresponding selftests. The USP/USD kernel updates are already in my local
tree.

That said, there is a sequence for landing new features. Right now we need
to wait for Andrea’s NEXT-C-SID and PSP series[2] to get merged into net-next
first.

[1] https://lore.kernel.org/netdev/20260922-srv6_flavors_endx-v1-0-4d01c05c47b7@kylinos.cn/
[2] https://lore.kernel.org/netdev/20261011192310.55-1-andrea.mayer@uniroma2.it/

Thanks
Hangbin