To have access and store not only BPF prog pointer, but also auxiliary params on Generic (skb) XDP path, replace it with an &xdp_attachment_info struct and use xdp_attachment_setup_rcu() (since Generic XDP code RCU-protects the pointer already). This slightly changes the struct &net_device cacheline layout, but nothing performance-critical. Signed-off-by: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx> --- include/linux/netdevice.h | 7 +++---- net/bpf/dev.c | 11 ++++------- net/core/dev.c | 4 +++- net/core/rtnetlink.c | 2 +- 4 files changed, 11 insertions(+), 13 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 60df42b3f116..1c033c164257 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2168,7 +2168,7 @@ struct net_device { unsigned int num_rx_queues; unsigned int real_num_rx_queues; - struct bpf_prog __rcu *xdp_prog; + struct xdp_attachment_info xdp_info; unsigned long gro_flush_timeout; int napi_defer_hard_irqs; #define GRO_LEGACY_MAX_SIZE 65536u @@ -2343,9 +2343,8 @@ struct net_device { static inline bool netif_elide_gro(const struct net_device *dev) { - if (!(dev->features & NETIF_F_GRO) || dev->xdp_prog) - return true; - return false; + return !(dev->features & NETIF_F_GRO) || + rcu_access_pointer(dev->xdp_info.prog_rcu); } #define NETDEV_ALIGN 32 diff --git a/net/bpf/dev.c b/net/bpf/dev.c index 82948d0536c8..cc43f73929f3 100644 --- a/net/bpf/dev.c +++ b/net/bpf/dev.c @@ -242,19 +242,16 @@ static void dev_disable_gro_hw(struct net_device *dev) static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp) { - struct bpf_prog *old = rtnl_dereference(dev->xdp_prog); - struct bpf_prog *new = xdp->prog; + bool old = !!rtnl_dereference(dev->xdp_info.prog_rcu); int ret = 0; switch (xdp->command) { case XDP_SETUP_PROG: - rcu_assign_pointer(dev->xdp_prog, new); - if (old) - bpf_prog_put(old); + xdp_attachment_setup_rcu(&dev->xdp_info, xdp); - if (old && !new) { + if (old && !xdp->prog) { static_branch_dec(&generic_xdp_needed_key); - } else if (new && !old) { + } else if (xdp->prog && !old) { static_branch_inc(&generic_xdp_needed_key); dev_disable_lro(dev); dev_disable_gro_hw(dev); diff --git a/net/core/dev.c b/net/core/dev.c index 62bf6ee00741..e57ae87d619e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5055,10 +5055,12 @@ static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc, __this_cpu_inc(softnet_data.processed); if (static_branch_unlikely(&generic_xdp_needed_key)) { + struct bpf_prog *prog; int ret2; migrate_disable(); - ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb); + prog = rcu_dereference(skb->dev->xdp_info.prog_rcu); + ret2 = do_xdp_generic(prog, skb); migrate_enable(); if (ret2 != XDP_PASS) { diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 500420d5017c..72f696b12df2 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1451,7 +1451,7 @@ static u32 rtnl_xdp_prog_skb(struct net_device *dev) ASSERT_RTNL(); - generic_xdp_prog = rtnl_dereference(dev->xdp_prog); + generic_xdp_prog = rtnl_dereference(dev->xdp_info.prog_rcu); if (!generic_xdp_prog) return 0; return generic_xdp_prog->aux->id; -- 2.36.1