Xuan Zhuo
2023-Oct-16 12:00 UTC
[PATCH net-next v1 16/19] virtio_net: xsk: rx: introduce receive_xsk() to recv xsk buffer
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 at 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)
+{
+ 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
Jason Wang
2023-Oct-20 06:57 UTC
[PATCH net-next v1 16/19] virtio_net: xsk: rx: introduce receive_xsk() to recv xsk buffer
On Mon, Oct 16, 2023 at 8:01?PM Xuan Zhuo <xuanzhuo at 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 at 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