[PATCH RFC v1 00/15] XDP extend with knowledge of frame size

Early RFC *before* I finish converting all drivers... so I can get
feedback that might affect the design...

XDP have evolved to support several frame sizes, but xdp_buff was not
updated with this information. This have caused the side-effect that XDP
frame data hard end is not known. It also limited the BPF-helper
bpf_xdp_adjust_tail to only shrink the packet.

This patchset tries to address this and add packet tail extend/grow.

The purpose of the patchset is ALSO to reserve a memory area that can be
used for storing extra information, specifically for extending XDP with
multi-buffer support. One proposal is to use same layout as
skb_shared_info, which is why this area is currently 320 bytes.

---

Jesper Dangaard Brouer (15):
      xdp: add frame size to xdp_buff
      mvneta: add XDP frame size to driver
      bnxt: add XDP frame size to driver
      ixgbe: fix XDP redirect on archs with PAGE_SIZE above 4K
      ixgbe: add XDP frame size to driver
      sfc: fix XDP-redirect in this driver
      sfc: add XDP frame size
      xdp: allow bpf_xdp_adjust_tail() to grow packet size
      xdp: clear grow memory in bpf_xdp_adjust_tail()
      net: XDP-generic determining XDP frame size
      xdp: xdp_frame add member frame_sz and handle in convert_to_xdp_frame
      xdp: cpumap redirect use frame_sz and increase skb_tailroom
      tun: add XDP frame size
      veth: xdp using frame_sz in veth driver
      dpaa2-eth: add XDP frame size


 drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c    |    1 +
 drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c |    1 +
 drivers/net/ethernet/intel/ixgbe/ixgbe.h         |   17 ++++++++++++
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c    |   17 +++++++-----
 drivers/net/ethernet/marvell/mvneta.c            |    1 +
 drivers/net/ethernet/sfc/efx_common.c            |    9 ++++--
 drivers/net/ethernet/sfc/net_driver.h            |    6 ++++
 drivers/net/ethernet/sfc/rx.c                    |    3 +-
 drivers/net/ethernet/sfc/rx_common.c             |    6 ++--
 drivers/net/tun.c                                |    2 +
 drivers/net/veth.c                               |   15 +++++++++--
 include/net/xdp.h                                |   31 +++++++++++++++++++++-
 include/uapi/linux/bpf.h                         |    4 +--
 kernel/bpf/cpumap.c                              |   21 ++-------------
 net/core/dev.c                                   |   14 ++++++----
 net/core/filter.c                                |   24 ++++++++++++++++-
 net/core/xdp.c                                   |    7 +++++
 17 files changed, 133 insertions(+), 46 deletions(-)

--