| Message ID | 20231016120033.26933-17-xuanzhuo@linux.alibaba.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | virtio-net: support AF_XDP zero copy | expand |
On Mon, Oct 16, 2023 at 8:01 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > 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 <xuanzhuo@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 0e740447b142..003dd67ab707 100644 > --- a/drivers/net/virtio/main.c > +++ b/drivers/net/virtio/main.c > @@ -822,10 +822,10 @@ 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; > @@ -1589,13 +1589,17 @@ 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 6e71622fca45..fd7f34703c9b 100644 > --- a/drivers/net/virtio/virtio_net.h > +++ b/drivers/net/virtio/virtio_net.h > @@ -346,6 +346,10 @@ 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 841fb078882a..f1c64414fac9 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) > +{ I wonder if anything blocks us from reusing the existing XDP logic? Are there some subtle differences? Thanks
On Fri, 20 Oct 2023 14:57:06 +0800, Jason Wang <jasowang@redhat.com> wrote: > On Mon, Oct 16, 2023 at 8:01 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > 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 <xuanzhuo@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 0e740447b142..003dd67ab707 100644 > > --- a/drivers/net/virtio/main.c > > +++ b/drivers/net/virtio/main.c > > @@ -822,10 +822,10 @@ 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; > > @@ -1589,13 +1589,17 @@ 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 6e71622fca45..fd7f34703c9b 100644 > > --- a/drivers/net/virtio/virtio_net.h > > +++ b/drivers/net/virtio/virtio_net.h > > @@ -346,6 +346,10 @@ 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 841fb078882a..f1c64414fac9 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) > > +{ > > I wonder if anything blocks us from reusing the existing XDP logic? > Are there some subtle differences? 1. We need to copy data to create skb for XDP_PASS. 2. We need to call xsk_buff_free() to release the buffer. 3. The handle for xdp_buff is difference. virtnet_xdp_handler() is re-used. So the receive code is simple. If we pushed this function into existing code, we would have to maintain code scattered inside merge and small (and big). So I think it is a good choice for us to put the xsk code into a function. Thanks. > > Thanks >
On Fri, 20 Oct 2023 14:57:06 +0800, Jason Wang <jasowang@redhat.com> wrote: > On Mon, Oct 16, 2023 at 8:01 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > 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 <xuanzhuo@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 0e740447b142..003dd67ab707 100644 > > --- a/drivers/net/virtio/main.c > > +++ b/drivers/net/virtio/main.c > > @@ -822,10 +822,10 @@ 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; > > @@ -1589,13 +1589,17 @@ 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 6e71622fca45..fd7f34703c9b 100644 > > --- a/drivers/net/virtio/virtio_net.h > > +++ b/drivers/net/virtio/virtio_net.h > > @@ -346,6 +346,10 @@ 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 841fb078882a..f1c64414fac9 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) > > +{ > > I wonder if anything blocks us from reusing the existing XDP logic? > Are there some subtle differences? About this, "the existing XDP logic" do you mean virtnet_xdp_handler()? This function reuse it. virtnet_receive_xsk is on the same level with receive_mergeable. I do the mergeable logic and small logic inside this function. Do you have any question on why we introduce this function? I tried to do inside receive_mergeable/small, but that be difficult. Because that the buf,ctx is differ from the origin logic. So I think introducing an new handler is the right way. Thanks. > > Thanks >
diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c index 0e740447b142..003dd67ab707 100644 --- a/drivers/net/virtio/main.c +++ b/drivers/net/virtio/main.c @@ -822,10 +822,10 @@ 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; @@ -1589,13 +1589,17 @@ 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 6e71622fca45..fd7f34703c9b 100644 --- a/drivers/net/virtio/virtio_net.h +++ b/drivers/net/virtio/virtio_net.h @@ -346,6 +346,10 @@ 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 841fb078882a..f1c64414fac9 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
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 <xuanzhuo@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(-)