From 9fc8d518d9d590998209f2686e026a488f65d41e Mon Sep 17 00:00:00 2001 From: Toshiaki Makita Date: Fri, 3 Aug 2018 16:58:13 +0900 Subject: veth: Handle xdp_frames in xdp napi ring This is preparation for XDP TX and ndo_xdp_xmit. This allows napi handler to handle xdp_frames through xdp ring as well as sk_buff. v8: - Don't use xdp_frame pointer address to calculate skb->head and headroom. v7: - Use xdp_scrub_frame() instead of memset(). v3: - Revert v2 change around rings and use a flag to differentiate skb and xdp_frame, since bulk skb xmit makes little performance difference for now. v2: - Use another ring instead of using flag to differentiate skb and xdp_frame. This approach makes bulk skb transmit possible in veth_xmit later. - Clear xdp_frame feilds in skb->head. - Implement adjust_tail. Signed-off-by: Toshiaki Makita Acked-by: John Fastabend Acked-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann --- drivers/net/veth.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 84 insertions(+), 5 deletions(-) (limited to 'drivers/net/veth.c') diff --git a/drivers/net/veth.c b/drivers/net/veth.c index 9edf104739da..89f3059e603d 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -22,12 +22,12 @@ #include #include #include -#include #include #define DRV_NAME "veth" #define DRV_VERSION "1.0" +#define VETH_XDP_FLAG BIT(0) #define VETH_RING_SIZE 256 #define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN) @@ -115,6 +115,24 @@ static const struct ethtool_ops veth_ethtool_ops = { /* general routines */ +static bool veth_is_xdp_frame(void *ptr) +{ + return (unsigned long)ptr & VETH_XDP_FLAG; +} + +static void *veth_ptr_to_xdp(void *ptr) +{ + return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG); +} + +static void veth_ptr_free(void *ptr) +{ + if (veth_is_xdp_frame(ptr)) + xdp_return_frame(veth_ptr_to_xdp(ptr)); + else + kfree_skb(ptr); +} + static void __veth_xdp_flush(struct veth_priv *priv) { /* Write ptr_ring before reading rx_notify_masked */ @@ -249,6 +267,63 @@ static struct sk_buff *veth_build_skb(void *head, int headroom, int len, return skb; } +static struct sk_buff *veth_xdp_rcv_one(struct veth_priv *priv, + struct xdp_frame *frame) +{ + void *hard_start = frame->data - frame->headroom; + void *head = hard_start - sizeof(struct xdp_frame); + int len = frame->len, delta = 0; + struct bpf_prog *xdp_prog; + unsigned int headroom; + struct sk_buff *skb; + + rcu_read_lock(); + xdp_prog = rcu_dereference(priv->xdp_prog); + if (likely(xdp_prog)) { + struct xdp_buff xdp; + u32 act; + + xdp.data_hard_start = hard_start; + xdp.data = frame->data; + xdp.data_end = frame->data + frame->len; + xdp.data_meta = frame->data - frame->metasize; + xdp.rxq = &priv->xdp_rxq; + + act = bpf_prog_run_xdp(xdp_prog, &xdp); + + switch (act) { + case XDP_PASS: + delta = frame->data - xdp.data; + len = xdp.data_end - xdp.data; + break; + default: + bpf_warn_invalid_xdp_action(act); + case XDP_ABORTED: + trace_xdp_exception(priv->dev, xdp_prog, act); + case XDP_DROP: + goto err_xdp; + } + } + rcu_read_unlock(); + + headroom = sizeof(struct xdp_frame) + frame->headroom - delta; + skb = veth_build_skb(head, headroom, len, 0); + if (!skb) { + xdp_return_frame(frame); + goto err; + } + + xdp_scrub_frame(frame); + skb->protocol = eth_type_trans(skb, priv->dev); +err: + return skb; +err_xdp: + rcu_read_unlock(); + xdp_return_frame(frame); + + return NULL; +} + static struct sk_buff *veth_xdp_rcv_skb(struct veth_priv *priv, struct sk_buff *skb) { @@ -359,12 +434,16 @@ static int veth_xdp_rcv(struct veth_priv *priv, int budget) int i, done = 0; for (i = 0; i < budget; i++) { - struct sk_buff *skb = __ptr_ring_consume(&priv->xdp_ring); + void *ptr = __ptr_ring_consume(&priv->xdp_ring); + struct sk_buff *skb; - if (!skb) + if (!ptr) break; - skb = veth_xdp_rcv_skb(priv, skb); + if (veth_is_xdp_frame(ptr)) + skb = veth_xdp_rcv_one(priv, veth_ptr_to_xdp(ptr)); + else + skb = veth_xdp_rcv_skb(priv, ptr); if (skb) napi_gro_receive(&priv->xdp_napi, skb); @@ -417,7 +496,7 @@ static void veth_napi_del(struct net_device *dev) napi_disable(&priv->xdp_napi); netif_napi_del(&priv->xdp_napi); priv->rx_notify_masked = false; - ptr_ring_cleanup(&priv->xdp_ring, __skb_array_destroy_skb); + ptr_ring_cleanup(&priv->xdp_ring, veth_ptr_free); } static int veth_enable_xdp(struct net_device *dev) -- cgit v1.2.3-59-g8ed1b