diff options
| -rw-r--r-- | drivers/net/virtio_net.c | 173 | ||||
| -rw-r--r-- | include/linux/virtio_net.h | 9 |
2 files changed, 162 insertions, 20 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 27559c9..e6b5d6e 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -34,6 +34,7 @@ module_param(gso, bool, 0444); /* FIXME: MTU in config. */ #define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN) +#define GOOD_COPY_LEN 128 struct virtnet_info { @@ -58,6 +59,9 @@ struct virtnet_info /* I like... big packets and I cannot lie! */ bool big_packets; + /* Host will merge rx buffers for big packets (shake it! shake it!) */ + bool mergeable_rx_bufs; + /* Receive & send queues. */ struct sk_buff_head recv; struct sk_buff_head send; @@ -66,16 +70,11 @@ struct virtnet_info struct page *pages; }; -static inline struct virtio_net_hdr *skb_vnet_hdr(struct sk_buff *skb) +static inline void *skb_vnet_hdr(struct sk_buff *skb) { return (struct virtio_net_hdr *)skb->cb; } -static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb) -{ - sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr)); -} - static void give_a_page(struct virtnet_info *vi, struct page *page) { page->private = (unsigned long)vi->pages; @@ -121,25 +120,97 @@ static void skb_xmit_done(struct virtqueue *svq) static void receive_skb(struct net_device *dev, struct sk_buff *skb, unsigned len) { + struct virtnet_info *vi = netdev_priv(dev); struct virtio_net_hdr *hdr = skb_vnet_hdr(skb); int err; + int i; if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { pr_debug("%s: short packet %i\n", dev->name, len); dev->stats.rx_length_errors++; goto drop; } - len -= sizeof(struct virtio_net_hdr); - if (len <= MAX_PACKET_LEN) - trim_pages(netdev_priv(dev), skb); + if (vi->mergeable_rx_bufs) { + struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb); + unsigned int copy; + char *p = page_address(skb_shinfo(skb)->frags[0].page); - err = pskb_trim(skb, len); - if (err) { - pr_debug("%s: pskb_trim failed %i %d\n", dev->name, len, err); - dev->stats.rx_dropped++; - goto drop; + if (len > PAGE_SIZE) + len = PAGE_SIZE; + len -= sizeof(struct virtio_net_hdr_mrg_rxbuf); + + memcpy(hdr, p, sizeof(*mhdr)); + p += sizeof(*mhdr); + + copy = len; + if (copy > skb_tailroom(skb)) + copy = skb_tailroom(skb); + + memcpy(skb_put(skb, copy), p, copy); + + len -= copy; + + if (!len) { + give_a_page(vi, skb_shinfo(skb)->frags[0].page); + skb_shinfo(skb)->nr_frags--; + } else { + skb_shinfo(skb)->frags[0].page_offset += + sizeof(*mhdr) + copy; + skb_shinfo(skb)->frags[0].size = len; + skb->data_len += len; + skb->len += len; + } + + while (--mhdr->num_buffers) { + struct sk_buff *nskb; + + i = skb_shinfo(skb)->nr_frags; + if (i >= MAX_SKB_FRAGS) { + pr_debug("%s: packet too long %d\n", dev->name, + len); + dev->stats.rx_length_errors++; + goto drop; + } + + nskb = vi->rvq->vq_ops->get_buf(vi->rvq, &len); + if (!nskb) { + pr_debug("%s: rx error: %d buffers missing\n", + dev->name, mhdr->num_buffers); + dev->stats.rx_length_errors++; + goto drop; + } + + __skb_unlink(nskb, &vi->recv); + vi->num--; + + skb_shinfo(skb)->frags[i] = skb_shinfo(nskb)->frags[0]; + skb_shinfo(nskb)->nr_frags = 0; + kfree_skb(nskb); + + if (len > PAGE_SIZE) + len = PAGE_SIZE; + + skb_shinfo(skb)->frags[i].size = len; + skb_shinfo(skb)->nr_frags++; + skb->data_len += len; + skb->len += len; + } + } else { + len -= sizeof(struct virtio_net_hdr); + + if (len <= MAX_PACKET_LEN) + trim_pages(vi, skb); + + err = pskb_trim(skb, len); + if (err) { + pr_debug("%s: pskb_trim failed %i %d\n", dev->name, + len, err); + dev->stats.rx_dropped++; + goto drop; + } } + skb->truesize += skb->data_len; dev->stats.rx_bytes += skb->len; dev->stats.rx_packets++; @@ -198,7 +269,7 @@ drop: dev_kfree_skb(skb); } -static void try_fill_recv(struct virtnet_info *vi) +static void try_fill_recv_maxbufs(struct virtnet_info *vi) { struct sk_buff *skb; struct scatterlist sg[2+MAX_SKB_FRAGS]; @@ -206,12 +277,16 @@ static void try_fill_recv(struct virtnet_info *vi) sg_init_table(sg, 2+MAX_SKB_FRAGS); for (;;) { + struct virtio_net_hdr *hdr; + skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN); if (unlikely(!skb)) break; skb_put(skb, MAX_PACKET_LEN); - vnet_hdr_to_sg(sg, skb); + + hdr = skb_vnet_hdr(skb); + sg_init_one(sg, hdr, sizeof(*hdr)); if (vi->big_packets) { for (i = 0; i < MAX_SKB_FRAGS; i++) { @@ -247,6 +322,54 @@ static void try_fill_recv(struct virtnet_info *vi) vi->rvq->vq_ops->kick(vi->rvq); } +static void try_fill_recv(struct virtnet_info *vi) +{ + struct sk_buff *skb; + struct scatterlist sg[1]; + int err; + + if (!vi->mergeable_rx_bufs) { + try_fill_recv_maxbufs(vi); + return; + } + + for (;;) { + skb_frag_t *f; + + skb = netdev_alloc_skb(vi->dev, GOOD_COPY_LEN + NET_IP_ALIGN); + if (unlikely(!skb)) + break; + + skb_reserve(skb, NET_IP_ALIGN); + + f = &skb_shinfo(skb)->frags[0]; + f->page = get_a_page(vi, GFP_ATOMIC); + if (!f->page) { + kfree_skb(skb); + break; + } + + f->page_offset = 0; + f->size = PAGE_SIZE; + + skb_shinfo(skb)->nr_frags++; + + sg_init_one(sg, page_address(f->page), PAGE_SIZE); + skb_queue_head(&vi->recv, skb); + + err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 1, skb); + if (err) { + skb_unlink(skb, &vi->recv); + kfree_skb(skb); + break; + } + vi->num++; + } + if (unlikely(vi->num > vi->max)) + vi->max = vi->num; + vi->rvq->vq_ops->kick(vi->rvq); +} + static void skb_recv_done(struct virtqueue *rvq) { struct virtnet_info *vi = rvq->vdev->priv; @@ -325,15 +448,14 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) { int num, err; struct scatterlist sg[2+MAX_SKB_FRAGS]; - struct virtio_net_hdr *hdr; + struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb); + struct virtio_net_hdr *hdr = skb_vnet_hdr(skb); const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; sg_init_table(sg, 2+MAX_SKB_FRAGS); pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); - /* Encode metadata header at front. */ - hdr = skb_vnet_hdr(skb); if (skb->ip_summed == CHECKSUM_PARTIAL) { hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; hdr->csum_start = skb->csum_start - skb_headroom(skb); @@ -361,7 +483,14 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) hdr->gso_size = hdr->hdr_len = 0; } - vnet_hdr_to_sg(sg, skb); + mhdr->num_buffers = 0; + + /* Encode metadata header at front. */ + if (vi->mergeable_rx_bufs) + sg_init_one(sg, mhdr, sizeof(*mhdr)); + else + sg_init_one(sg, hdr, sizeof(*hdr)); + num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1; err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb); @@ -551,6 +680,9 @@ static int virtnet_probe(struct virtio_device *vdev) || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) vi->big_packets = true; + if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) + vi->mergeable_rx_bufs = true; + /* We expect two virtqueues, receive then send. */ vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done); if (IS_ERR(vi->rvq)) { @@ -643,6 +775,7 @@ static unsigned int features[] = { VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */ + VIRTIO_NET_F_MRG_RXBUF, VIRTIO_F_NOTIFY_ON_EMPTY, }; diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 5e33761..5cdd0aa 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -20,6 +20,7 @@ #define VIRTIO_NET_F_HOST_TSO6 12 /* Host can handle TSOv6 in. */ #define VIRTIO_NET_F_HOST_ECN 13 /* Host can handle TSO[6] w/ ECN in. */ #define VIRTIO_NET_F_HOST_UFO 14 /* Host can handle UFO in. */ +#define VIRTIO_NET_F_MRG_RXBUF 15 /* Host can merge receive buffers. */ struct virtio_net_config { @@ -44,4 +45,12 @@ struct virtio_net_hdr __u16 csum_start; /* Position to start checksumming from */ __u16 csum_offset; /* Offset after that to place checksum */ }; + +/* This is the version of the header to use when the MRG_RXBUF + * feature has been negotiated. */ +struct virtio_net_hdr_mrg_rxbuf { + struct virtio_net_hdr hdr; + __u16 num_buffers; /* Number of merged rx buffers */ +}; + #endif /* _LINUX_VIRTIO_NET_H */ |