Re: [PATCH net v4] igb: Fix XDP with PTP enabled

Hi Maintainers,

What is the status on this patch?

I don't see this fix being applied on git-trees net or net-next.

[0] 20210503072800.79936-1-kurt@linutronix.de
[1] https://patchwork.kernel.org/project/netdevbpf/patch/20210503072800.79936-1-kurt@linutronix.de/
[2] https://lore.kernel.org/netdev/20210503072800.79936-1-kurt@linutronix.de/ (local)


On Tue, 4 May 2021 10:28:27 +0200
Jesper Dangaard Brouer [off-list ref] wrote:

On Mon,  3 May 2021 09:28:00 +0200
Kurt Kanzenbach [off-list ref] wrote:

quoted

When using native XDP with the igb driver, the XDP frame data doesn't point to
the beginning of the packet. It's off by 16 bytes. Everything works as expected
with XDP skb mode.

Actually these 16 bytes are used to store the packet timestamps. Therefore, pull
the timestamp before executing any XDP operations and adjust all other code
accordingly. The igc driver does it like that as well.

Tested with Intel i210 card and AF_XDP sockets.

Fixes: 9cbc948b5a20 ("igb: add XDP support")
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>  

Thanks for fixing this!

Acked-by: Jesper Dangaard Brouer <redacted>

I expect that we/I will (soon) play with getting this area that is
stored in front of the packet (the XDP data_meta area) described via
BTF.  This way both xdp_frame and AF_XDP can get structured access (e.g.
to the PTP timestamp in this case).

I'll be adding my notes on this project here:
 https://github.com/xdp-project/xdp-project/blob/master/areas/tsn/

Looking forward to collaborate on this with you :-)

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer