Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
[safe/jmp/linux-2.6] / drivers / net / virtio_net.c
index 27559c9..43f6523 100644 (file)
@@ -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++) {
@@ -247,13 +322,61 @@ 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;
        /* Schedule NAPI, Suppress further interrupts if successful. */
-       if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
+       if (netif_rx_schedule_prep(&vi->napi)) {
                rvq->vq_ops->disable_cb(rvq);
-               __netif_rx_schedule(vi->dev, &vi->napi);
+               __netif_rx_schedule(&vi->napi);
        }
 }
 
@@ -279,11 +402,11 @@ again:
 
        /* Out of packets? */
        if (received < budget) {
-               netif_rx_complete(vi->dev, napi);
+               netif_rx_complete(napi);
                if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
                    && napi_schedule_prep(napi)) {
                        vi->rvq->vq_ops->disable_cb(vi->rvq);
-                       __netif_rx_schedule(vi->dev, napi);
+                       __netif_rx_schedule(napi);
                        goto again;
                }
        }
@@ -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);
@@ -451,9 +580,9 @@ static int virtnet_open(struct net_device *dev)
         * won't get another interrupt, so process any outstanding packets
         * now.  virtnet_poll wants re-enable the queue, so we disable here.
         * We synchronize against interrupts via NAPI_STATE_SCHED */
-       if (netif_rx_schedule_prep(dev, &vi->napi)) {
+       if (netif_rx_schedule_prep(&vi->napi)) {
                vi->rvq->vq_ops->disable_cb(vi->rvq);
-               __netif_rx_schedule(dev, &vi->napi);
+               __netif_rx_schedule(&vi->napi);
        }
        return 0;
 }
@@ -484,6 +613,29 @@ static struct ethtool_ops virtnet_ethtool_ops = {
        .set_tso = ethtool_op_set_tso,
 };
 
+#define MIN_MTU 68
+#define MAX_MTU 65535
+
+static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
+{
+       if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
+               return -EINVAL;
+       dev->mtu = new_mtu;
+       return 0;
+}
+
+static const struct net_device_ops virtnet_netdev = {
+       .ndo_open            = virtnet_open,
+       .ndo_stop            = virtnet_close,
+       .ndo_start_xmit      = start_xmit,
+       .ndo_validate_addr   = eth_validate_addr,
+       .ndo_set_mac_address = eth_mac_addr,
+       .ndo_change_mtu      = virtnet_change_mtu,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+       .ndo_poll_controller = virtnet_netpoll,
+#endif
+};
+
 static int virtnet_probe(struct virtio_device *vdev)
 {
        int err;
@@ -496,13 +648,8 @@ static int virtnet_probe(struct virtio_device *vdev)
                return -ENOMEM;
 
        /* Set up network device as normal. */
-       dev->open = virtnet_open;
-       dev->stop = virtnet_close;
-       dev->hard_start_xmit = start_xmit;
+       dev->netdev_ops = &virtnet_netdev;
        dev->features = NETIF_F_HIGHDMA;
-#ifdef CONFIG_NET_POLL_CONTROLLER
-       dev->poll_controller = virtnet_netpoll;
-#endif
        SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
        SET_NETDEV_DEV(dev, &vdev->dev);
 
@@ -551,6 +698,9 @@ 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 +793,7 @@ 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,
 };