Implementing the logic of xsk rx. If this packet is not for XSK determined in XDP, then we need to copy once to generate a SKB. If it is for XSK, it is a zerocopy receive packet process.
Signed-off-by: Xuan Zhuo <xuanz...@linux.alibaba.com> --- drivers/net/virtio/main.c | 14 ++-- drivers/net/virtio/virtio_net.h | 4 ++ drivers/net/virtio/xsk.c | 120 ++++++++++++++++++++++++++++++++ drivers/net/virtio/xsk.h | 4 ++ 4 files changed, 137 insertions(+), 5 deletions(-) diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c index 55a643a1f129..61be5a353ff3 100644 --- a/drivers/net/virtio/main.c +++ b/drivers/net/virtio/main.c @@ -828,10 +828,10 @@ static void put_xdp_frags(struct xdp_buff *xdp) } } -static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, - struct net_device *dev, - unsigned int *xdp_xmit, - struct virtnet_rq_stats *stats) +int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, + struct net_device *dev, + unsigned int *xdp_xmit, + struct virtnet_rq_stats *stats) { struct xdp_frame *xdpf; int err; @@ -1595,13 +1595,17 @@ static void receive_buf(struct virtnet_info *vi, struct virtnet_rq *rq, return; } - if (vi->mergeable_rx_bufs) + rcu_read_lock(); + if (rcu_dereference(rq->xsk.pool)) + skb = virtnet_receive_xsk(dev, vi, rq, buf, len, xdp_xmit, stats); + else if (vi->mergeable_rx_bufs) skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit, stats); else if (vi->big_packets) skb = receive_big(dev, vi, rq, buf, len, stats); else skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats); + rcu_read_unlock(); if (unlikely(!skb)) return; diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h index 532df71a4c08..a8aa1a68a237 100644 --- a/drivers/net/virtio/virtio_net.h +++ b/drivers/net/virtio/virtio_net.h @@ -345,6 +345,10 @@ static inline bool virtnet_is_xdp_raw_buffer_queue(struct virtnet_info *vi, int return false; } +int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, + struct net_device *dev, + unsigned int *xdp_xmit, + struct virtnet_rq_stats *stats); void virtnet_rx_pause(struct virtnet_info *vi, struct virtnet_rq *rq); void virtnet_rx_resume(struct virtnet_info *vi, struct virtnet_rq *rq); void virtnet_tx_pause(struct virtnet_info *vi, struct virtnet_sq *sq); diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c index d7f0a81e8635..7abd46bb0e3d 100644 --- a/drivers/net/virtio/xsk.c +++ b/drivers/net/virtio/xsk.c @@ -13,6 +13,18 @@ static void sg_fill_dma(struct scatterlist *sg, dma_addr_t addr, u32 len) sg->length = len; } +static unsigned int virtnet_receive_buf_num(struct virtnet_info *vi, char *buf) +{ + struct virtio_net_hdr_mrg_rxbuf *hdr; + + if (vi->mergeable_rx_bufs) { + hdr = (struct virtio_net_hdr_mrg_rxbuf *)buf; + return virtio16_to_cpu(vi->vdev, hdr->num_buffers); + } + + return 1; +} + static void virtnet_xsk_check_queue(struct virtnet_sq *sq) { struct virtnet_info *vi = sq->vq->vdev->priv; @@ -37,6 +49,114 @@ static void virtnet_xsk_check_queue(struct virtnet_sq *sq) netif_stop_subqueue(dev, qnum); } +static void merge_drop_follow_xdp(struct net_device *dev, + struct virtnet_rq *rq, + u32 num_buf, + struct virtnet_rq_stats *stats) +{ + struct xdp_buff *xdp; + u32 len; + + while (num_buf-- > 1) { + xdp = virtqueue_get_buf(rq->vq, &len); + if (unlikely(!xdp)) { + pr_debug("%s: rx error: %d buffers missing\n", + dev->name, num_buf); + dev->stats.rx_length_errors++; + break; + } + stats->bytes += len; + xsk_buff_free(xdp); + } +} + +static struct sk_buff *construct_skb(struct virtnet_rq *rq, + struct xdp_buff *xdp) +{ + unsigned int metasize = xdp->data - xdp->data_meta; + struct sk_buff *skb; + unsigned int size; + + size = xdp->data_end - xdp->data_hard_start; + skb = napi_alloc_skb(&rq->napi, size); + if (unlikely(!skb)) + return NULL; + + skb_reserve(skb, xdp->data_meta - xdp->data_hard_start); + + size = xdp->data_end - xdp->data_meta; + memcpy(__skb_put(skb, size), xdp->data_meta, size); + + if (metasize) { + __skb_pull(skb, metasize); + skb_metadata_set(skb, metasize); + } + + return skb; +} + +struct sk_buff *virtnet_receive_xsk(struct net_device *dev, struct virtnet_info *vi, + struct virtnet_rq *rq, void *buf, + unsigned int len, unsigned int *xdp_xmit, + struct virtnet_rq_stats *stats) +{ + struct virtio_net_hdr_mrg_rxbuf *hdr; + struct sk_buff *skb = NULL; + u32 ret, headroom, num_buf; + struct bpf_prog *prog; + struct xdp_buff *xdp; + + len -= vi->hdr_len; + + xdp = (struct xdp_buff *)buf; + + xsk_buff_set_size(xdp, len); + + hdr = xdp->data - vi->hdr_len; + + num_buf = virtnet_receive_buf_num(vi, (char *)hdr); + if (num_buf > 1) + goto drop; + + headroom = xdp->data - xdp->data_hard_start; + + xdp_prepare_buff(xdp, xdp->data_hard_start, headroom, len, true); + xsk_buff_dma_sync_for_cpu(xdp, rq->xsk.pool); + + ret = XDP_PASS; + rcu_read_lock(); + prog = rcu_dereference(rq->xdp_prog); + if (prog) + ret = virtnet_xdp_handler(prog, xdp, dev, xdp_xmit, stats); + rcu_read_unlock(); + + switch (ret) { + case XDP_PASS: + skb = construct_skb(rq, xdp); + xsk_buff_free(xdp); + break; + + case XDP_TX: + case XDP_REDIRECT: + goto consumed; + + default: + goto drop; + } + + return skb; + +drop: + stats->drops++; + + xsk_buff_free(xdp); + + if (num_buf > 1) + merge_drop_follow_xdp(dev, rq, num_buf, stats); +consumed: + return NULL; +} + static int virtnet_add_recvbuf_batch(struct virtnet_info *vi, struct virtnet_rq *rq, struct xsk_buff_pool *pool, gfp_t gfp) { diff --git a/drivers/net/virtio/xsk.h b/drivers/net/virtio/xsk.h index bef41a3f954e..dbd2839a5f61 100644 --- a/drivers/net/virtio/xsk.h +++ b/drivers/net/virtio/xsk.h @@ -25,4 +25,8 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool, int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag); int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct virtnet_rq *rq, struct xsk_buff_pool *pool, gfp_t gfp); +struct sk_buff *virtnet_receive_xsk(struct net_device *dev, struct virtnet_info *vi, + struct virtnet_rq *rq, void *buf, + unsigned int len, unsigned int *xdp_xmit, + struct virtnet_rq_stats *stats); #endif -- 2.32.0.3.g01195cf9f _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization