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

   1 From 7cda76d858a4e71ac4a04066c093679a12e1312c Mon Sep 17 00:00:00 2001
   2 From: Lorenzo Bianconi <lorenzo@kernel.org>
   3 Date: Fri, 11 Mar 2022 10:14:20 +0100
   4 Subject: [PATCH] veth: Allow jumbo frames in xdp mode
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Allow increasing the MTU over page boundaries on veth devices
  10 if the attached xdp program declares to support xdp fragments.
  11
  12 Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
  13 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
  14 Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
  15 Acked-by: John Fastabend <john.fastabend@gmail.com>
  16 Link: https://lore.kernel.org/bpf/d5dc039c3d4123426e7023a488c449181a7bc57f.1646989407.git.lorenzo@kernel.org
  17 ---
  18  drivers/net/veth.c | 11 ++++++++---
  19  1 file changed, 8 insertions(+), 3 deletions(-)
  20
  21 diff --git a/drivers/net/veth.c b/drivers/net/veth.c
  22 index bfae15ec902b..1b5714926d81 100644
  23 --- a/drivers/net/veth.c
  24 +++ b/drivers/net/veth.c
  25 @@ -1470,9 +1470,14 @@ static int veth_xdp_set(struct net_devic
  26                         goto err;
  27                 }
  28
  29 -               max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
  30 -                         peer->hard_header_len -
  31 -                         SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
  32 +               max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -
  33 +                         peer->hard_header_len;
  34 +               /* Allow increasing the max_mtu if the program supports
  35 +                * XDP fragments.
  36 +                */
  37 +               //if (prog->aux->xdp_has_frags)
  38 +               max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;
  39 +
  40                 if (peer->mtu > max_mtu) {
  41                         NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
  42                         err = -ERANGE;