[PATCH net-next RFC v1 4/4] veth: when XDP is loaded increase needed_headroom
From: Jesper Dangaard Brouer <hawk@kernel.org>
Date: 2023-08-22 17:59:31
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
When sending (sendmsg) SKBs out an veth device, the SKB headroom is too small to satisfy XDP on the receiving veth peer device. For AF_XDP (normal non-zero-copy) it is worth noticing that xsk_build_skb() adjust headroom according to dev->needed_headroom. Other parts of the kernel also take this into account (see macro LL_RESERVED_SPACE). This solves the XDP_PACKET_HEADROOM check in veth_convert_skb_to_xdp_buff(). Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org> --- drivers/net/veth.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 8e117cc44fda..3630e9124071 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c@@ -1649,6 +1649,7 @@ static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog, if (!old_prog) { peer->hw_features &= ~NETIF_F_GSO_SOFTWARE; peer->max_mtu = max_mtu; + veth_set_rx_headroom(dev, XDP_PACKET_HEADROOM); } xdp_features_set_redirect_target(peer, true);
@@ -1666,6 +1667,7 @@ static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog, peer->hw_features |= NETIF_F_GSO_SOFTWARE; peer->max_mtu = ETH_MAX_MTU; } + veth_set_rx_headroom(dev, -1); } bpf_prog_put(old_prog); }