target/linux/generic/backport-5.15/609-v5.18-veth-Allow-jumbo-frames-in-xdp-mode.patch

   1 commit 7cda76d858a4e71ac4a04066c093679a12e1312c
   2 Author: Lorenzo Bianconi <lorenzo@kernel.org>
   3 Date:   Fri Mar 11 10:14:20 2022 +0100
   4
   5     veth: Allow jumbo frames in xdp mode
   6
   7     Allow increasing the MTU over page boundaries on veth devices
   8     if the attached xdp program declares to support xdp fragments.
   9
  10     Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
  11     Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
  12     Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
  13     Acked-by: John Fastabend <john.fastabend@gmail.com>
  14     Link: https://lore.kernel.org/bpf/d5dc039c3d4123426e7023a488c449181a7bc57f.1646989407.git.lorenzo@kernel.org
  15
  16 --- a/drivers/net/veth.c
  17 +++ b/drivers/net/veth.c
  18 @@ -1470,9 +1470,14 @@ static int veth_xdp_set(struct net_devic
  19                         goto err;
  20                 }
  21
  22 -               max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
  23 -                         peer->hard_header_len -
  24 -                         SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
  25 +               max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -
  26 +                         peer->hard_header_len;
  27 +               /* Allow increasing the max_mtu if the program supports
  28 +                * XDP fragments.
  29 +                */
  30 +               //if (prog->aux->xdp_has_frags)
  31 +               max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;
  32 +
  33                 if (peer->mtu > max_mtu) {
  34                         NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
  35                         err = -ERANGE;