-----Original Message-----
From: Intel-wired-lan <redacted> On Behalf Of
Alexander Lobakin
Sent: Wednesday, December 8, 2021 7:37 PM
To: intel-wired-lan@lists.osuosl.org
Cc: Song Liu <redacted>; Jesper Dangaard Brouer
[off-list ref]; Daniel Borkmann [off-list ref]; Yonghong
Song [off-list ref]; Martin KaFai Lau [off-list ref]; John Fastabend
[off-list ref]; Alexei Starovoitov [off-list ref]; Andrii
Nakryiko [off-list ref]; Björn Töpel [off-list ref];
netdev@vger.kernel.org; Jakub Kicinski [off-list ref]; KP Singh
[off-list ref]; bpf@vger.kernel.org; David S. Miller
[off-list ref]; linux-kernel@vger.kernel.org
Subject: [Intel-wired-lan] [PATCH v4 net-next 0/9] net: intel: napi_alloc_skb()
vs metadata

This is an interpolation of [0] to other Intel Ethernet drivers (and is (re)based
on its code).
The main aim is to keep XDP metadata not only in case with build_skb(), but
also when we do napi_alloc_skb() + memcpy().

All Intel drivers suffers from the same here:
 - metadata gets lost on XDP_PASS in legacy-rx;
 - excessive headroom allocation on XSK Rx to skbs;
 - metadata gets lost on XSK Rx to skbs.

Those get especially actual in XDP Hints upcoming.
I couldn't have addressed the first one for all Intel drivers due to that they
don't reserve any headroom for now in legacy-rx mode even with XDP
enabled. This is hugely wrong, but requires quite a bunch of work and a
separate series. Luckily, ice doesn't suffer from that.
igc has 1 and 3 already fixed in [0].

From v3 ([1]):
 - fix driver name and ixgbe_construct_skb() function name in the
   commit message of #9 (Jesper);
 - no functional changes.

From v2 (unreleased upstream):
 - tweaked 007 to pass bi->xdp directly and simplify code (Maciej);
 - picked Michal's Reviewed-by.

From v1 (unreleased upstream):
 - drop "fixes" of legacy-rx for i40e, igb and ixgbe since they have
   another flaw regarding headroom (see above);
 - drop igc cosmetic fixes since they landed upstream incorporated
   into Jesper's commits;
 - picked one Acked-by from Maciej.

[0]
https://lore.kernel.org/netdev/163700856423.565980.101625649213476937
58.stgit@firesoul
[1] https://lore.kernel.org/netdev/20211207205536.563550-1-
alexandr.lobakin@intel.com

Alexander Lobakin (9):
  i40e: don't reserve excessive XDP_PACKET_HEADROOM on XSK Rx to skb
  i40e: respect metadata on XSK Rx to skb
  ice: respect metadata in legacy-rx/ice_construct_skb()
  ice: don't reserve excessive XDP_PACKET_HEADROOM on XSK Rx to skb
  ice: respect metadata on XSK Rx to skb
  igc: don't reserve excessive XDP_PACKET_HEADROOM on XSK Rx to skb
  ixgbe: pass bi->xdp to ixgbe_construct_skb_zc() directly
  ixgbe: don't reserve excessive XDP_PACKET_HEADROOM on XSK Rx to skb
  ixgbe: respect metadata on XSK Rx to skb

 drivers/net/ethernet/intel/i40e/i40e_xsk.c   | 16 +++++++-----
 drivers/net/ethernet/intel/ice/ice_txrx.c    | 15 ++++++++---
 drivers/net/ethernet/intel/ice/ice_xsk.c     | 16 +++++++-----
 drivers/net/ethernet/intel/igc/igc_main.c    | 13 +++++-----
 drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 27 ++++++++++++--------
 5 files changed, 54 insertions(+), 33 deletions(-)

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