RE: [Intel-wired-lan] [PATCH v3 net-next 2/9] i40e: respect metadata on XSK Rx to skb

-----Original Message-----
From: Intel-wired-lan <redacted> On Behalf Of
Lobakin, Alexandr
Sent: Wednesday, December 8, 2021 2:25 AM
To: intel-wired-lan@lists.osuosl.org
Cc: Andre Guedes <redacted>; Jesper Dangaard Brouer
[off-list ref]; Daniel Borkmann [off-list ref];
netdev@vger.kernel.org; Krzysztof Kazimierczak
[off-list ref]; bpf@vger.kernel.org; John Fastabend
[off-list ref]; Alexei Starovoitov [off-list ref]; Brouer,
Jesper [off-list ref]; Björn Töpel [off-list ref]; Jeff Kirsher
[off-list ref]; Jakub Kicinski [off-list ref]; linux-
kernel@vger.kernel.org; David S. Miller [off-list ref]; Vedang
Patel [off-list ref]
Subject: [Intel-wired-lan] [PATCH v3 net-next 2/9] i40e: respect metadata on
XSK Rx to skb

For now, if the XDP prog returns XDP_PASS on XSK, the metadata will be lost
as it doesn't get copied to the skb.
Copy it along with the frame headers. Account its size on skb allocation, and
when copying just treat it as a part of the frame and do a pull after to "move"
it to the "reserved" zone.
net_prefetch() xdp->data_meta and align the copy size to speed-up
memcpy() a little and better match i40e_costruct_skb().

Fixes: 0a714186d3c0 ("i40e: add AF_XDP zero-copy Rx support")
Suggested-by: Jesper Dangaard Brouer <redacted>
Suggested-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Alexander Lobakin <redacted>
Reviewed-by: Michal Swiatkowski <redacted>
---
 drivers/net/ethernet/intel/i40e/i40e_xsk.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

Tested-by: Kiran Bhandare <redacted>  A Contingent Worker at Intel