libata-sff: ap->[last_]ctl are SFF specific
[safe/jmp/linux-2.6] / drivers / net / virtio_net.c
index 222f3d0..b0577dd 100644 (file)
@@ -1,4 +1,4 @@
-/* A simple network driver using virtio.
+/* A network driver using virtio.
  *
  * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
  *
 #include <linux/ethtool.h>
 #include <linux/module.h>
 #include <linux/virtio.h>
-#include <linux/virtio_ids.h>
 #include <linux/virtio_net.h>
 #include <linux/scatterlist.h>
 #include <linux/if_vlan.h>
+#include <linux/slab.h>
 
 static int napi_weight = 128;
 module_param(napi_weight, int, 0444);
@@ -48,26 +48,15 @@ struct virtnet_info
        struct napi_struct napi;
        unsigned int status;
 
-       /* If we need to free in a timer, this is it. */
-       struct timer_list xmit_free_timer;
-
        /* Number of input buffers, and max we've ever had. */
        unsigned int num, max;
 
-       /* For cleaning up after transmission. */
-       struct tasklet_struct tasklet;
-       bool free_in_tasklet;
-
        /* 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;
-
        /* Work struct for refilling if we run low on memory. */
        struct delayed_work refill;
 
@@ -75,34 +64,52 @@ struct virtnet_info
        struct page *pages;
 };
 
-static inline void *skb_vnet_hdr(struct sk_buff *skb)
-{
-       return (struct virtio_net_hdr *)skb->cb;
-}
+struct skb_vnet_hdr {
+       union {
+               struct virtio_net_hdr hdr;
+               struct virtio_net_hdr_mrg_rxbuf mhdr;
+       };
+       unsigned int num_sg;
+};
 
-static void give_a_page(struct virtnet_info *vi, struct page *page)
+struct padded_vnet_hdr {
+       struct virtio_net_hdr hdr;
+       /*
+        * virtio_net_hdr should be in a separated sg buffer because of a
+        * QEMU bug, and data sg buffer shares same page with this header sg.
+        * This padding makes next sg 16 byte aligned after virtio_net_hdr.
+        */
+       char padding[6];
+};
+
+static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
 {
-       page->private = (unsigned long)vi->pages;
-       vi->pages = page;
+       return (struct skb_vnet_hdr *)skb->cb;
 }
 
-static void trim_pages(struct virtnet_info *vi, struct sk_buff *skb)
+/*
+ * private is used to chain pages for big packets, put the whole
+ * most recent used list in the beginning for reuse
+ */
+static void give_pages(struct virtnet_info *vi, struct page *page)
 {
-       unsigned int i;
+       struct page *end;
 
-       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
-               give_a_page(vi, skb_shinfo(skb)->frags[i].page);
-       skb_shinfo(skb)->nr_frags = 0;
-       skb->data_len = 0;
+       /* Find end of list, sew whole thing into vi->pages. */
+       for (end = page; end->private; end = (struct page *)end->private);
+       end->private = (unsigned long)vi->pages;
+       vi->pages = page;
 }
 
 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
 {
        struct page *p = vi->pages;
 
-       if (p)
+       if (p) {
                vi->pages = (struct page *)p->private;
-       else
+               /* clear private here, it is used to chain pages */
+               p->private = 0;
+       } else
                p = alloc_page(gfp_mask);
        return p;
 }
@@ -116,112 +123,153 @@ static void skb_xmit_done(struct virtqueue *svq)
 
        /* We were probably waiting for more output buffers. */
        netif_wake_queue(vi->dev);
+}
 
-       if (vi->free_in_tasklet)
-               tasklet_schedule(&vi->tasklet);
+static void set_skb_frag(struct sk_buff *skb, struct page *page,
+                        unsigned int offset, unsigned int *len)
+{
+       int i = skb_shinfo(skb)->nr_frags;
+       skb_frag_t *f;
+
+       f = &skb_shinfo(skb)->frags[i];
+       f->size = min((unsigned)PAGE_SIZE - offset, *len);
+       f->page_offset = offset;
+       f->page = page;
+
+       skb->data_len += f->size;
+       skb->len += f->size;
+       skb_shinfo(skb)->nr_frags++;
+       *len -= f->size;
 }
 
-static void receive_skb(struct net_device *dev, struct sk_buff *skb,
-                       unsigned len)
+static struct sk_buff *page_to_skb(struct virtnet_info *vi,
+                                  struct page *page, unsigned int len)
 {
-       struct virtnet_info *vi = netdev_priv(dev);
-       struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
-       int err;
-       int i;
+       struct sk_buff *skb;
+       struct skb_vnet_hdr *hdr;
+       unsigned int copy, hdr_len, offset;
+       char *p;
 
-       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;
-       }
+       p = page_address(page);
 
-       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);
+       /* copy small packet so we can reuse these pages for small data */
+       skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
+       if (unlikely(!skb))
+               return NULL;
 
-               if (len > PAGE_SIZE)
-                       len = PAGE_SIZE;
-               len -= sizeof(struct virtio_net_hdr_mrg_rxbuf);
+       hdr = skb_vnet_hdr(skb);
+
+       if (vi->mergeable_rx_bufs) {
+               hdr_len = sizeof hdr->mhdr;
+               offset = hdr_len;
+       } else {
+               hdr_len = sizeof hdr->hdr;
+               offset = sizeof(struct padded_vnet_hdr);
+       }
 
-               memcpy(hdr, p, sizeof(*mhdr));
-               p += sizeof(*mhdr);
+       memcpy(hdr, p, hdr_len);
 
-               copy = len;
-               if (copy > skb_tailroom(skb))
-                       copy = skb_tailroom(skb);
+       len -= hdr_len;
+       p += offset;
 
-               memcpy(skb_put(skb, copy), p, copy);
+       copy = len;
+       if (copy > skb_tailroom(skb))
+               copy = skb_tailroom(skb);
+       memcpy(skb_put(skb, copy), p, copy);
 
-               len -= copy;
+       len -= copy;
+       offset += 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 (len) {
+               set_skb_frag(skb, page, offset, &len);
+               page = (struct page *)page->private;
+               offset = 0;
+       }
 
-               while (--mhdr->num_buffers) {
-                       struct sk_buff *nskb;
+       if (page)
+               give_pages(vi, page);
 
-                       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;
-                       }
+       return skb;
+}
 
-                       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;
-                       }
+static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
+{
+       struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
+       struct page *page;
+       int num_buf, i, len;
+
+       num_buf = hdr->mhdr.num_buffers;
+       while (--num_buf) {
+               i = skb_shinfo(skb)->nr_frags;
+               if (i >= MAX_SKB_FRAGS) {
+                       pr_debug("%s: packet too long\n", skb->dev->name);
+                       skb->dev->stats.rx_length_errors++;
+                       return -EINVAL;
+               }
 
-                       __skb_unlink(nskb, &vi->recv);
-                       vi->num--;
+               page = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
+               if (!page) {
+                       pr_debug("%s: rx error: %d buffers missing\n",
+                                skb->dev->name, hdr->mhdr.num_buffers);
+                       skb->dev->stats.rx_length_errors++;
+                       return -EINVAL;
+               }
+               if (len > PAGE_SIZE)
+                       len = PAGE_SIZE;
 
-                       skb_shinfo(skb)->frags[i] = skb_shinfo(nskb)->frags[0];
-                       skb_shinfo(nskb)->nr_frags = 0;
-                       kfree_skb(nskb);
+               set_skb_frag(skb, page, 0, &len);
 
-                       if (len > PAGE_SIZE)
-                               len = PAGE_SIZE;
+               --vi->num;
+       }
+       return 0;
+}
 
-                       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);
+static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
+{
+       struct virtnet_info *vi = netdev_priv(dev);
+       struct sk_buff *skb;
+       struct page *page;
+       struct skb_vnet_hdr *hdr;
 
-               if (len <= MAX_PACKET_LEN)
-                       trim_pages(vi, skb);
+       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++;
+               if (vi->mergeable_rx_bufs || vi->big_packets)
+                       give_pages(vi, buf);
+               else
+                       dev_kfree_skb(buf);
+               return;
+       }
 
-               err = pskb_trim(skb, len);
-               if (err) {
-                       pr_debug("%s: pskb_trim failed %i %d\n", dev->name,
-                                len, err);
+       if (!vi->mergeable_rx_bufs && !vi->big_packets) {
+               skb = buf;
+               len -= sizeof(struct virtio_net_hdr);
+               skb_trim(skb, len);
+       } else {
+               page = buf;
+               skb = page_to_skb(vi, page, len);
+               if (unlikely(!skb)) {
                        dev->stats.rx_dropped++;
-                       goto drop;
+                       give_pages(vi, page);
+                       return;
                }
+               if (vi->mergeable_rx_bufs)
+                       if (receive_mergeable(vi, skb)) {
+                               dev_kfree_skb(skb);
+                               return;
+                       }
        }
 
+       hdr = skb_vnet_hdr(skb);
        skb->truesize += skb->data_len;
        dev->stats.rx_bytes += skb->len;
        dev->stats.rx_packets++;
 
-       if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
+       if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
                pr_debug("Needs csum!\n");
-               if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
+               if (!skb_partial_csum_set(skb,
+                                         hdr->hdr.csum_start,
+                                         hdr->hdr.csum_offset))
                        goto frame_err;
        }
 
@@ -229,9 +277,9 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb,
        pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
                 ntohs(skb->protocol), skb->len, skb->pkt_type);
 
-       if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
+       if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
                pr_debug("GSO!\n");
-               switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
+               switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
                case VIRTIO_NET_HDR_GSO_TCPV4:
                        skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
                        break;
@@ -244,14 +292,14 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb,
                default:
                        if (net_ratelimit())
                                printk(KERN_WARNING "%s: bad gso type %u.\n",
-                                      dev->name, hdr->gso_type);
+                                      dev->name, hdr->hdr.gso_type);
                        goto frame_err;
                }
 
-               if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
+               if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
                        skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 
-               skb_shinfo(skb)->gso_size = hdr->gso_size;
+               skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
                if (skb_shinfo(skb)->gso_size == 0) {
                        if (net_ratelimit())
                                printk(KERN_WARNING "%s: zero gso size.\n",
@@ -269,114 +317,122 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb,
 
 frame_err:
        dev->stats.rx_frame_errors++;
-drop:
        dev_kfree_skb(skb);
 }
 
-static bool try_fill_recv_maxbufs(struct virtnet_info *vi, gfp_t gfp)
+static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
 {
        struct sk_buff *skb;
-       struct scatterlist sg[2+MAX_SKB_FRAGS];
-       int num, err, i;
-       bool oom = false;
-
-       sg_init_table(sg, 2+MAX_SKB_FRAGS);
-       for (;;) {
-               struct virtio_net_hdr *hdr;
+       struct skb_vnet_hdr *hdr;
+       struct scatterlist sg[2];
+       int err;
 
-               skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN + NET_IP_ALIGN);
-               if (unlikely(!skb)) {
-                       oom = true;
-                       break;
-               }
+       sg_init_table(sg, 2);
+       skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN);
+       if (unlikely(!skb))
+               return -ENOMEM;
 
-               skb_reserve(skb, NET_IP_ALIGN);
-               skb_put(skb, MAX_PACKET_LEN);
+       skb_put(skb, MAX_PACKET_LEN);
 
-               hdr = skb_vnet_hdr(skb);
-               sg_set_buf(sg, hdr, sizeof(*hdr));
+       hdr = skb_vnet_hdr(skb);
+       sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr);
 
-               if (vi->big_packets) {
-                       for (i = 0; i < MAX_SKB_FRAGS; i++) {
-                               skb_frag_t *f = &skb_shinfo(skb)->frags[i];
-                               f->page = get_a_page(vi, gfp);
-                               if (!f->page)
-                                       break;
+       skb_to_sgvec(skb, sg + 1, 0, skb->len);
 
-                               f->page_offset = 0;
-                               f->size = PAGE_SIZE;
+       err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 2, skb);
+       if (err < 0)
+               dev_kfree_skb(skb);
 
-                               skb->data_len += PAGE_SIZE;
-                               skb->len += PAGE_SIZE;
+       return err;
+}
 
-                               skb_shinfo(skb)->nr_frags++;
-                       }
+static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
+{
+       struct scatterlist sg[MAX_SKB_FRAGS + 2];
+       struct page *first, *list = NULL;
+       char *p;
+       int i, err, offset;
+
+       sg_init_table(sg, MAX_SKB_FRAGS + 2);
+       /* page in sg[MAX_SKB_FRAGS + 1] is list tail */
+       for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
+               first = get_a_page(vi, gfp);
+               if (!first) {
+                       if (list)
+                               give_pages(vi, list);
+                       return -ENOMEM;
                }
+               sg_set_buf(&sg[i], page_address(first), PAGE_SIZE);
 
-               num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
-               skb_queue_head(&vi->recv, skb);
+               /* chain new page in list head to match sg */
+               first->private = (unsigned long)list;
+               list = first;
+       }
 
-               err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
-               if (err < 0) {
-                       skb_unlink(skb, &vi->recv);
-                       trim_pages(vi, skb);
-                       kfree_skb(skb);
-                       break;
-               }
-               vi->num++;
+       first = get_a_page(vi, gfp);
+       if (!first) {
+               give_pages(vi, list);
+               return -ENOMEM;
        }
-       if (unlikely(vi->num > vi->max))
-               vi->max = vi->num;
-       vi->rvq->vq_ops->kick(vi->rvq);
-       return !oom;
+       p = page_address(first);
+
+       /* sg[0], sg[1] share the same page */
+       /* a separated sg[0] for  virtio_net_hdr only during to QEMU bug*/
+       sg_set_buf(&sg[0], p, sizeof(struct virtio_net_hdr));
+
+       /* sg[1] for data packet, from offset */
+       offset = sizeof(struct padded_vnet_hdr);
+       sg_set_buf(&sg[1], p + offset, PAGE_SIZE - offset);
+
+       /* chain first in list head */
+       first->private = (unsigned long)list;
+       err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, MAX_SKB_FRAGS + 2,
+                                      first);
+       if (err < 0)
+               give_pages(vi, first);
+
+       return err;
 }
 
-/* Returns false if we couldn't fill entirely (OOM). */
-static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
+static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
 {
-       struct sk_buff *skb;
-       struct scatterlist sg[1];
+       struct page *page;
+       struct scatterlist sg;
        int err;
-       bool oom = false;
-
-       if (!vi->mergeable_rx_bufs)
-               return try_fill_recv_maxbufs(vi, gfp);
 
-       for (;;) {
-               skb_frag_t *f;
-
-               skb = netdev_alloc_skb(vi->dev, GOOD_COPY_LEN + NET_IP_ALIGN);
-               if (unlikely(!skb)) {
-                       oom = true;
-                       break;
-               }
+       page = get_a_page(vi, gfp);
+       if (!page)
+               return -ENOMEM;
 
-               skb_reserve(skb, NET_IP_ALIGN);
+       sg_init_one(&sg, page_address(page), PAGE_SIZE);
 
-               f = &skb_shinfo(skb)->frags[0];
-               f->page = get_a_page(vi, gfp);
-               if (!f->page) {
-                       oom = true;
-                       kfree_skb(skb);
-                       break;
-               }
+       err = vi->rvq->vq_ops->add_buf(vi->rvq, &sg, 0, 1, page);
+       if (err < 0)
+               give_pages(vi, page);
 
-               f->page_offset = 0;
-               f->size = PAGE_SIZE;
+       return err;
+}
 
-               skb_shinfo(skb)->nr_frags++;
+/* Returns false if we couldn't fill entirely (OOM). */
+static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
+{
+       int err;
+       bool oom = false;
 
-               sg_init_one(sg, page_address(f->page), PAGE_SIZE);
-               skb_queue_head(&vi->recv, skb);
+       do {
+               if (vi->mergeable_rx_bufs)
+                       err = add_recvbuf_mergeable(vi, gfp);
+               else if (vi->big_packets)
+                       err = add_recvbuf_big(vi, gfp);
+               else
+                       err = add_recvbuf_small(vi, gfp);
 
-               err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 1, skb);
                if (err < 0) {
-                       skb_unlink(skb, &vi->recv);
-                       kfree_skb(skb);
+                       oom = true;
                        break;
                }
-               vi->num++;
-       }
+               ++vi->num;
+       } while (err > 0);
        if (unlikely(vi->num > vi->max))
                vi->max = vi->num;
        vi->rvq->vq_ops->kick(vi->rvq);
@@ -400,8 +456,7 @@ static void refill_work(struct work_struct *work)
 
        vi = container_of(work, struct virtnet_info, refill.work);
        napi_disable(&vi->napi);
-       try_fill_recv(vi, GFP_KERNEL);
-       still_empty = (vi->num == 0);
+       still_empty = !try_fill_recv(vi, GFP_KERNEL);
        napi_enable(&vi->napi);
 
        /* In theory, this can happen: if we don't get any buffers in
@@ -413,15 +468,14 @@ static void refill_work(struct work_struct *work)
 static int virtnet_poll(struct napi_struct *napi, int budget)
 {
        struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
-       struct sk_buff *skb = NULL;
+       void *buf;
        unsigned int len, received = 0;
 
 again:
        while (received < budget &&
-              (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
-               __skb_unlink(skb, &vi->recv);
-               receive_skb(vi->dev, skb, len);
-               vi->num--;
+              (buf = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
+               receive_buf(vi->dev, buf, len);
+               --vi->num;
                received++;
        }
 
@@ -433,8 +487,8 @@ again:
        /* Out of packets? */
        if (received < budget) {
                napi_complete(napi);
-               if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
-                   && napi_schedule_prep(napi)) {
+               if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) &&
+                   napi_schedule_prep(napi)) {
                        vi->rvq->vq_ops->disable_cb(vi->rvq);
                        __napi_schedule(napi);
                        goto again;
@@ -444,42 +498,25 @@ again:
        return received;
 }
 
-static void free_old_xmit_skbs(struct virtnet_info *vi)
+static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
 {
        struct sk_buff *skb;
-       unsigned int len;
+       unsigned int len, tot_sgs = 0;
 
        while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
                pr_debug("Sent skb %p\n", skb);
-               __skb_unlink(skb, &vi->send);
                vi->dev->stats.tx_bytes += skb->len;
                vi->dev->stats.tx_packets++;
-               kfree_skb(skb);
+               tot_sgs += skb_vnet_hdr(skb)->num_sg;
+               dev_kfree_skb_any(skb);
        }
-}
-
-/* If the virtio transport doesn't always notify us when all in-flight packets
- * are consumed, we fall back to using this function on a timer to free them. */
-static void xmit_free(unsigned long data)
-{
-       struct virtnet_info *vi = (void *)data;
-
-       netif_tx_lock(vi->dev);
-
-       free_old_xmit_skbs(vi);
-
-       if (!skb_queue_empty(&vi->send))
-               mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
-
-       netif_tx_unlock(vi->dev);
+       return tot_sgs;
 }
 
 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_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
-       struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
+       struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
        const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 
        sg_init_table(sg, 2+MAX_SKB_FRAGS);
@@ -487,90 +524,88 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
        pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 
        if (skb->ip_summed == CHECKSUM_PARTIAL) {
-               hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-               hdr->csum_start = skb->csum_start - skb_headroom(skb);
-               hdr->csum_offset = skb->csum_offset;
+               hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
+               hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb);
+               hdr->hdr.csum_offset = skb->csum_offset;
        } else {
-               hdr->flags = 0;
-               hdr->csum_offset = hdr->csum_start = 0;
+               hdr->hdr.flags = 0;
+               hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
        }
 
        if (skb_is_gso(skb)) {
-               hdr->hdr_len = skb_headlen(skb);
-               hdr->gso_size = skb_shinfo(skb)->gso_size;
+               hdr->hdr.hdr_len = skb_headlen(skb);
+               hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
                if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
-                       hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
+                       hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
                else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
-                       hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
+                       hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
                else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
-                       hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
+                       hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
                else
                        BUG();
                if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
-                       hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
+                       hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
        } else {
-               hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
-               hdr->gso_size = hdr->hdr_len = 0;
+               hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
+               hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
        }
 
-       mhdr->num_buffers = 0;
+       hdr->mhdr.num_buffers = 0;
 
        /* Encode metadata header at front. */
        if (vi->mergeable_rx_bufs)
-               sg_set_buf(sg, mhdr, sizeof(*mhdr));
+               sg_set_buf(sg, &hdr->mhdr, sizeof hdr->mhdr);
        else
-               sg_set_buf(sg, hdr, sizeof(*hdr));
-
-       num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
+               sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr);
 
-       err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
-       if (err >= 0 && !vi->free_in_tasklet) {
-               /* Don't wait up for transmitted skbs to be freed. */
-               skb_orphan(skb);
-               nf_reset(skb);
-               mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
-       }
-
-       return err;
-}
-
-static void xmit_tasklet(unsigned long data)
-{
-       struct virtnet_info *vi = (void *)data;
-
-       netif_tx_lock_bh(vi->dev);
-       free_old_xmit_skbs(vi);
-       netif_tx_unlock_bh(vi->dev);
+       hdr->num_sg = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
+       return vi->svq->vq_ops->add_buf(vi->svq, sg, hdr->num_sg, 0, skb);
 }
 
 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct virtnet_info *vi = netdev_priv(dev);
+       int capacity;
 
 again:
        /* Free up any pending old buffers before queueing new ones. */
        free_old_xmit_skbs(vi);
 
-       /* Put new one in send queue and do transmit */
-       __skb_queue_head(&vi->send, skb);
-       if (likely(xmit_skb(vi, skb) >= 0)) {
-               vi->svq->vq_ops->kick(vi->svq);
-               return NETDEV_TX_OK;
-       }
+       /* Try to transmit */
+       capacity = xmit_skb(vi, skb);
 
-       /* Ring too full for this packet, remove it from queue again. */
-       pr_debug("%s: virtio not prepared to send\n", dev->name);
-       __skb_unlink(skb, &vi->send);
-       netif_stop_queue(dev);
-
-       /* Activate callback for using skbs: if this returns false it
-        * means some were used in the meantime. */
-       if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
-               vi->svq->vq_ops->disable_cb(vi->svq);
-               netif_start_queue(dev);
-               goto again;
+       /* This can happen with OOM and indirect buffers. */
+       if (unlikely(capacity < 0)) {
+               netif_stop_queue(dev);
+               dev_warn(&dev->dev, "Unexpected full queue\n");
+               if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
+                       vi->svq->vq_ops->disable_cb(vi->svq);
+                       netif_start_queue(dev);
+                       goto again;
+               }
+               return NETDEV_TX_BUSY;
        }
-       return NETDEV_TX_BUSY;
+       vi->svq->vq_ops->kick(vi->svq);
+
+       /* Don't wait up for transmitted skbs to be freed. */
+       skb_orphan(skb);
+       nf_reset(skb);
+
+       /* Apparently nice girls don't return TX_BUSY; stop the queue
+        * before it gets out of hand.  Naturally, this wastes entries. */
+       if (capacity < 2+MAX_SKB_FRAGS) {
+               netif_stop_queue(dev);
+               if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
+                       /* More just got used, free them then recheck. */
+                       capacity += free_old_xmit_skbs(vi);
+                       if (capacity >= 2+MAX_SKB_FRAGS) {
+                               netif_start_queue(dev);
+                               vi->svq->vq_ops->disable_cb(vi->svq);
+                       }
+               }
+       }
+
+       return NETDEV_TX_OK;
 }
 
 static int virtnet_set_mac_address(struct net_device *dev, void *p)
@@ -689,6 +724,8 @@ static void virtnet_set_rx_mode(struct net_device *dev)
        struct virtio_net_ctrl_mac *mac_data;
        struct dev_addr_list *addr;
        struct netdev_hw_addr *ha;
+       int uc_count;
+       int mc_count;
        void *buf;
        int i;
 
@@ -715,9 +752,12 @@ static void virtnet_set_rx_mode(struct net_device *dev)
                dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
                         allmulti ? "en" : "dis");
 
+       uc_count = netdev_uc_count(dev);
+       mc_count = netdev_mc_count(dev);
        /* MAC filter - use one buffer for both lists */
-       mac_data = buf = kzalloc(((dev->uc.count + dev->mc_count) * ETH_ALEN) +
-                                (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
+       buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
+                     (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
+       mac_data = buf;
        if (!buf) {
                dev_warn(&dev->dev, "No memory for MAC address buffer\n");
                return;
@@ -726,24 +766,24 @@ static void virtnet_set_rx_mode(struct net_device *dev)
        sg_init_table(sg, 2);
 
        /* Store the unicast list and count in the front of the buffer */
-       mac_data->entries = dev->uc.count;
+       mac_data->entries = uc_count;
        i = 0;
-       list_for_each_entry(ha, &dev->uc.list, list)
+       netdev_for_each_uc_addr(ha, dev)
                memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 
        sg_set_buf(&sg[0], mac_data,
-                  sizeof(mac_data->entries) + (dev->uc.count * ETH_ALEN));
+                  sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
 
        /* multicast list and count fill the end */
-       mac_data = (void *)&mac_data->macs[dev->uc.count][0];
+       mac_data = (void *)&mac_data->macs[uc_count][0];
 
-       mac_data->entries = dev->mc_count;
-       addr = dev->mc_list;
-       for (i = 0; i < dev->mc_count; i++, addr = addr->next)
-               memcpy(&mac_data->macs[i][0], addr->da_addr, ETH_ALEN);
+       mac_data->entries = mc_count;
+       i = 0;
+       netdev_for_each_mc_addr(addr, dev)
+               memcpy(&mac_data->macs[i++][0], addr->da_addr, ETH_ALEN);
 
        sg_set_buf(&sg[1], mac_data,
-                  sizeof(mac_data->entries) + (dev->mc_count * ETH_ALEN));
+                  sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
 
        if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
                                  VIRTIO_NET_CTRL_MAC_TABLE_SET,
@@ -903,14 +943,10 @@ static int virtnet_probe(struct virtio_device *vdev)
        vi->pages = NULL;
        INIT_DELAYED_WORK(&vi->refill, refill_work);
 
-       /* If they give us a callback when all buffers are done, we don't need
-        * the timer. */
-       vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY);
-
        /* If we can receive ANY GSO packets, we must allocate large ones. */
-       if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4)
-           || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)
-           || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
+       if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
+           virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
+           virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
                vi->big_packets = true;
 
        if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
@@ -934,15 +970,6 @@ static int virtnet_probe(struct virtio_device *vdev)
                        dev->features |= NETIF_F_HW_VLAN_FILTER;
        }
 
-       /* Initialize our empty receive and send queues. */
-       skb_queue_head_init(&vi->recv);
-       skb_queue_head_init(&vi->send);
-
-       tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi);
-
-       if (!vi->free_in_tasklet)
-               setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi);
-
        err = register_netdev(dev);
        if (err) {
                pr_debug("virtio_net: registering device failed\n");
@@ -975,29 +1002,42 @@ free:
        return err;
 }
 
-static void virtnet_remove(struct virtio_device *vdev)
+static void free_unused_bufs(struct virtnet_info *vi)
+{
+       void *buf;
+       while (1) {
+               buf = vi->svq->vq_ops->detach_unused_buf(vi->svq);
+               if (!buf)
+                       break;
+               dev_kfree_skb(buf);
+       }
+       while (1) {
+               buf = vi->rvq->vq_ops->detach_unused_buf(vi->rvq);
+               if (!buf)
+                       break;
+               if (vi->mergeable_rx_bufs || vi->big_packets)
+                       give_pages(vi, buf);
+               else
+                       dev_kfree_skb(buf);
+               --vi->num;
+       }
+       BUG_ON(vi->num != 0);
+}
+
+static void __devexit virtnet_remove(struct virtio_device *vdev)
 {
        struct virtnet_info *vi = vdev->priv;
-       struct sk_buff *skb;
 
        /* Stop all the virtqueues. */
        vdev->config->reset(vdev);
 
-       if (!vi->free_in_tasklet)
-               del_timer_sync(&vi->xmit_free_timer);
-
-       /* Free our skbs in send and recv queues, if any. */
-       while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
-               kfree_skb(skb);
-               vi->num--;
-       }
-       __skb_queue_purge(&vi->send);
-
-       BUG_ON(vi->num != 0);
 
        unregister_netdev(vi->dev);
        cancel_delayed_work_sync(&vi->refill);
 
+       /* Free unused buffers in both send and recv, if any. */
+       free_unused_bufs(vi);
+
        vdev->config->del_vqs(vi->vdev);
 
        while (vi->pages)
@@ -1019,10 +1059,9 @@ static unsigned int features[] = {
        VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
        VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
        VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
-       VIRTIO_F_NOTIFY_ON_EMPTY,
 };
 
-static struct virtio_driver virtio_net = {
+static struct virtio_driver virtio_net_driver = {
        .feature_table = features,
        .feature_table_size = ARRAY_SIZE(features),
        .driver.name =  KBUILD_MODNAME,
@@ -1035,12 +1074,12 @@ static struct virtio_driver virtio_net = {
 
 static int __init init(void)
 {
-       return register_virtio_driver(&virtio_net);
+       return register_virtio_driver(&virtio_net_driver);
 }
 
 static void __exit fini(void)
 {
-       unregister_virtio_driver(&virtio_net);
+       unregister_virtio_driver(&virtio_net_driver);
 }
 module_init(init);
 module_exit(fini);