drivers/net/virtio_net.c

   1 /* A simple network driver using virtio.
   2  *
   3  * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19 //#define DEBUG
  20 #include <linux/netdevice.h>
  21 #include <linux/etherdevice.h>
  22 #include <linux/ethtool.h>
  23 #include <linux/module.h>
  24 #include <linux/virtio.h>
  25 #include <linux/virtio_net.h>
  26 #include <linux/scatterlist.h>
  27
  28 static int napi_weight = 128;
  29 module_param(napi_weight, int, 0444);
  30
  31 static int csum = 1, gso = 1;
  32 module_param(csum, bool, 0444);
  33 module_param(gso, bool, 0444);
  34
  35 /* FIXME: MTU in config. */
  36 #define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
  37
  38 struct virtnet_info
  39 {
  40         struct virtio_device *vdev;
  41         struct virtqueue *rvq, *svq;
  42         struct net_device *dev;
  43         struct napi_struct napi;
  44
  45         /* The skb we couldn't send because buffers were full. */
  46         struct sk_buff *last_xmit_skb;
  47
  48         /* If we need to free in a timer, this is it. */
  49         struct timer_list xmit_free_timer;
  50
  51         /* Number of input buffers, and max we've ever had. */
  52         unsigned int num, max;
  53
  54         /* For cleaning up after transmission. */
  55         struct tasklet_struct tasklet;
  56         bool free_in_tasklet;
  57
  58         /* I like... big packets and I cannot lie! */
  59         bool big_packets;
  60
  61         /* Receive & send queues. */
  62         struct sk_buff_head recv;
  63         struct sk_buff_head send;
  64
  65         /* Chain pages by the private ptr. */
  66         struct page *pages;
  67 };
  68
  69 static inline struct virtio_net_hdr *skb_vnet_hdr(struct sk_buff *skb)
  70 {
  71         return (struct virtio_net_hdr *)skb->cb;
  72 }
  73
  74 static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
  75 {
  76         sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
  77 }
  78
  79 static void give_a_page(struct virtnet_info *vi, struct page *page)
  80 {
  81         page->private = (unsigned long)vi->pages;
  82         vi->pages = page;
  83 }
  84
  85 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
  86 {
  87         struct page *p = vi->pages;
  88
  89         if (p)
  90                 vi->pages = (struct page *)p->private;
  91         else
  92                 p = alloc_page(gfp_mask);
  93         return p;
  94 }
  95
  96 static void skb_xmit_done(struct virtqueue *svq)
  97 {
  98         struct virtnet_info *vi = svq->vdev->priv;
  99
 100         /* Suppress further interrupts. */
 101         svq->vq_ops->disable_cb(svq);
 102
 103         /* We were probably waiting for more output buffers. */
 104         netif_wake_queue(vi->dev);
 105
 106         /* Make sure we re-xmit last_xmit_skb: if there are no more packets
 107          * queued, start_xmit won't be called. */
 108         tasklet_schedule(&vi->tasklet);
 109 }
 110
 111 static void receive_skb(struct net_device *dev, struct sk_buff *skb,
 112                         unsigned len)
 113 {
 114         struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
 115         int err;
 116
 117         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
 118                 pr_debug("%s: short packet %i\n", dev->name, len);
 119                 dev->stats.rx_length_errors++;
 120                 goto drop;
 121         }
 122         len -= sizeof(struct virtio_net_hdr);
 123
 124         if (len <= MAX_PACKET_LEN) {
 125                 unsigned int i;
 126
 127                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
 128                         give_a_page(dev->priv, skb_shinfo(skb)->frags[i].page);
 129                 skb->data_len = 0;
 130                 skb_shinfo(skb)->nr_frags = 0;
 131         }
 132
 133         err = pskb_trim(skb, len);
 134         if (err) {
 135                 pr_debug("%s: pskb_trim failed %i %d\n", dev->name, len, err);
 136                 dev->stats.rx_dropped++;
 137                 goto drop;
 138         }
 139         skb->truesize += skb->data_len;
 140         dev->stats.rx_bytes += skb->len;
 141         dev->stats.rx_packets++;
 142
 143         if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 144                 pr_debug("Needs csum!\n");
 145                 if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
 146                         goto frame_err;
 147         }
 148
 149         skb->protocol = eth_type_trans(skb, dev);
 150         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 151                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 152
 153         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 154                 pr_debug("GSO!\n");
 155                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 156                 case VIRTIO_NET_HDR_GSO_TCPV4:
 157                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 158                         break;
 159                 case VIRTIO_NET_HDR_GSO_UDP:
 160                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 161                         break;
 162                 case VIRTIO_NET_HDR_GSO_TCPV6:
 163                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 164                         break;
 165                 default:
 166                         if (net_ratelimit())
 167                                 printk(KERN_WARNING "%s: bad gso type %u.\n",
 168                                        dev->name, hdr->gso_type);
 169                         goto frame_err;
 170                 }
 171
 172                 if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
 173                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 174
 175                 skb_shinfo(skb)->gso_size = hdr->gso_size;
 176                 if (skb_shinfo(skb)->gso_size == 0) {
 177                         if (net_ratelimit())
 178                                 printk(KERN_WARNING "%s: zero gso size.\n",
 179                                        dev->name);
 180                         goto frame_err;
 181                 }
 182
 183                 /* Header must be checked, and gso_segs computed. */
 184                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 185                 skb_shinfo(skb)->gso_segs = 0;
 186         }
 187
 188         netif_receive_skb(skb);
 189         return;
 190
 191 frame_err:
 192         dev->stats.rx_frame_errors++;
 193 drop:
 194         dev_kfree_skb(skb);
 195 }
 196
 197 static void try_fill_recv(struct virtnet_info *vi)
 198 {
 199         struct sk_buff *skb;
 200         struct scatterlist sg[2+MAX_SKB_FRAGS];
 201         int num, err, i;
 202
 203         sg_init_table(sg, 2+MAX_SKB_FRAGS);
 204         for (;;) {
 205                 skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
 206                 if (unlikely(!skb))
 207                         break;
 208
 209                 skb_put(skb, MAX_PACKET_LEN);
 210                 vnet_hdr_to_sg(sg, skb);
 211
 212                 if (vi->big_packets) {
 213                         for (i = 0; i < MAX_SKB_FRAGS; i++) {
 214                                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
 215                                 f->page = get_a_page(vi, GFP_ATOMIC);
 216                                 if (!f->page)
 217                                         break;
 218
 219                                 f->page_offset = 0;
 220                                 f->size = PAGE_SIZE;
 221
 222                                 skb->data_len += PAGE_SIZE;
 223                                 skb->len += PAGE_SIZE;
 224
 225                                 skb_shinfo(skb)->nr_frags++;
 226                         }
 227                 }
 228
 229                 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
 230                 skb_queue_head(&vi->recv, skb);
 231
 232                 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
 233                 if (err) {
 234                         skb_unlink(skb, &vi->recv);
 235                         kfree_skb(skb);
 236                         break;
 237                 }
 238                 vi->num++;
 239         }
 240         if (unlikely(vi->num > vi->max))
 241                 vi->max = vi->num;
 242         vi->rvq->vq_ops->kick(vi->rvq);
 243 }
 244
 245 static void skb_recv_done(struct virtqueue *rvq)
 246 {
 247         struct virtnet_info *vi = rvq->vdev->priv;
 248         /* Schedule NAPI, Suppress further interrupts if successful. */
 249         if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
 250                 rvq->vq_ops->disable_cb(rvq);
 251                 __netif_rx_schedule(vi->dev, &vi->napi);
 252         }
 253 }
 254
 255 static int virtnet_poll(struct napi_struct *napi, int budget)
 256 {
 257         struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
 258         struct sk_buff *skb = NULL;
 259         unsigned int len, received = 0;
 260
 261 again:
 262         while (received < budget &&
 263                (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
 264                 __skb_unlink(skb, &vi->recv);
 265                 receive_skb(vi->dev, skb, len);
 266                 vi->num--;
 267                 received++;
 268         }
 269
 270         /* FIXME: If we oom and completely run out of inbufs, we need
 271          * to start a timer trying to fill more. */
 272         if (vi->num < vi->max / 2)
 273                 try_fill_recv(vi);
 274
 275         /* Out of packets? */
 276         if (received < budget) {
 277                 netif_rx_complete(vi->dev, napi);
 278                 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
 279                     && napi_schedule_prep(napi)) {
 280                         vi->rvq->vq_ops->disable_cb(vi->rvq);
 281                         __netif_rx_schedule(vi->dev, napi);
 282                         goto again;
 283                 }
 284         }
 285
 286         return received;
 287 }
 288
 289 static void free_old_xmit_skbs(struct virtnet_info *vi)
 290 {
 291         struct sk_buff *skb;
 292         unsigned int len;
 293
 294         while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
 295                 pr_debug("Sent skb %p\n", skb);
 296                 __skb_unlink(skb, &vi->send);
 297                 vi->dev->stats.tx_bytes += skb->len;
 298                 vi->dev->stats.tx_packets++;
 299                 kfree_skb(skb);
 300         }
 301 }
 302
 303 /* If the virtio transport doesn't always notify us when all in-flight packets
 304  * are consumed, we fall back to using this function on a timer to free them. */
 305 static void xmit_free(unsigned long data)
 306 {
 307         struct virtnet_info *vi = (void *)data;
 308
 309         netif_tx_lock(vi->dev);
 310
 311         free_old_xmit_skbs(vi);
 312
 313         if (!skb_queue_empty(&vi->send))
 314                 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
 315
 316         netif_tx_unlock(vi->dev);
 317 }
 318
 319 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
 320 {
 321         int num, err;
 322         struct scatterlist sg[2+MAX_SKB_FRAGS];
 323         struct virtio_net_hdr *hdr;
 324         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 325
 326         sg_init_table(sg, 2+MAX_SKB_FRAGS);
 327
 328         pr_debug("%s: xmit %p " MAC_FMT "\n", vi->dev->name, skb,
 329                  dest[0], dest[1], dest[2],
 330                  dest[3], dest[4], dest[5]);
 331
 332         /* Encode metadata header at front. */
 333         hdr = skb_vnet_hdr(skb);
 334         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 335                 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 336                 hdr->csum_start = skb->csum_start - skb_headroom(skb);
 337                 hdr->csum_offset = skb->csum_offset;
 338         } else {
 339                 hdr->flags = 0;
 340                 hdr->csum_offset = hdr->csum_start = 0;
 341         }
 342
 343         if (skb_is_gso(skb)) {
 344                 hdr->hdr_len = skb_transport_header(skb) - skb->data;
 345                 hdr->gso_size = skb_shinfo(skb)->gso_size;
 346                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 347                         hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 348                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 349                         hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 350                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 351                         hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
 352                 else
 353                         BUG();
 354                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 355                         hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 356         } else {
 357                 hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
 358                 hdr->gso_size = hdr->hdr_len = 0;
 359         }
 360
 361         vnet_hdr_to_sg(sg, skb);
 362         num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
 363
 364         err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
 365         if (!err && !vi->free_in_tasklet)
 366                 mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
 367
 368         return err;
 369 }
 370
 371 static void xmit_tasklet(unsigned long data)
 372 {
 373         struct virtnet_info *vi = (void *)data;
 374
 375         netif_tx_lock_bh(vi->dev);
 376         if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) {
 377                 vi->svq->vq_ops->kick(vi->svq);
 378                 vi->last_xmit_skb = NULL;
 379         }
 380         if (vi->free_in_tasklet)
 381                 free_old_xmit_skbs(vi);
 382         netif_tx_unlock_bh(vi->dev);
 383 }
 384
 385 static int start_xmit(struct sk_buff *skb, struct net_device *dev)
 386 {
 387         struct virtnet_info *vi = netdev_priv(dev);
 388
 389 again:
 390         /* Free up any pending old buffers before queueing new ones. */
 391         free_old_xmit_skbs(vi);
 392
 393         /* If we has a buffer left over from last time, send it now. */
 394         if (unlikely(vi->last_xmit_skb) &&
 395             xmit_skb(vi, vi->last_xmit_skb) != 0)
 396                 goto stop_queue;
 397
 398         vi->last_xmit_skb = NULL;
 399
 400         /* Put new one in send queue and do transmit */
 401         if (likely(skb)) {
 402                 __skb_queue_head(&vi->send, skb);
 403                 if (xmit_skb(vi, skb) != 0) {
 404                         vi->last_xmit_skb = skb;
 405                         skb = NULL;
 406                         goto stop_queue;
 407                 }
 408         }
 409 done:
 410         vi->svq->vq_ops->kick(vi->svq);
 411         return NETDEV_TX_OK;
 412
 413 stop_queue:
 414         pr_debug("%s: virtio not prepared to send\n", dev->name);
 415         netif_stop_queue(dev);
 416
 417         /* Activate callback for using skbs: if this returns false it
 418          * means some were used in the meantime. */
 419         if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
 420                 vi->svq->vq_ops->disable_cb(vi->svq);
 421                 netif_start_queue(dev);
 422                 goto again;
 423         }
 424         if (skb) {
 425                 /* Drop this skb: we only queue one. */
 426                 vi->dev->stats.tx_dropped++;
 427                 kfree_skb(skb);
 428         }
 429         goto done;
 430 }
 431
 432 #ifdef CONFIG_NET_POLL_CONTROLLER
 433 static void virtnet_netpoll(struct net_device *dev)
 434 {
 435         struct virtnet_info *vi = netdev_priv(dev);
 436
 437         napi_schedule(&vi->napi);
 438 }
 439 #endif
 440
 441 static int virtnet_open(struct net_device *dev)
 442 {
 443         struct virtnet_info *vi = netdev_priv(dev);
 444
 445         napi_enable(&vi->napi);
 446
 447         /* If all buffers were filled by other side before we napi_enabled, we
 448          * won't get another interrupt, so process any outstanding packets
 449          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 450          * We synchronize against interrupts via NAPI_STATE_SCHED */
 451         if (netif_rx_schedule_prep(dev, &vi->napi)) {
 452                 vi->rvq->vq_ops->disable_cb(vi->rvq);
 453                 __netif_rx_schedule(dev, &vi->napi);
 454         }
 455         return 0;
 456 }
 457
 458 static int virtnet_close(struct net_device *dev)
 459 {
 460         struct virtnet_info *vi = netdev_priv(dev);
 461
 462         napi_disable(&vi->napi);
 463
 464         return 0;
 465 }
 466
 467 static int virtnet_set_tx_csum(struct net_device *dev, u32 data)
 468 {
 469         struct virtnet_info *vi = netdev_priv(dev);
 470         struct virtio_device *vdev = vi->vdev;
 471
 472         if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
 473                 return -ENOSYS;
 474
 475         return ethtool_op_set_tx_hw_csum(dev, data);
 476 }
 477
 478 static struct ethtool_ops virtnet_ethtool_ops = {
 479         .set_tx_csum = virtnet_set_tx_csum,
 480         .set_sg = ethtool_op_set_sg,
 481 };
 482
 483 static int virtnet_probe(struct virtio_device *vdev)
 484 {
 485         int err;
 486         struct net_device *dev;
 487         struct virtnet_info *vi;
 488
 489         /* Allocate ourselves a network device with room for our info */
 490         dev = alloc_etherdev(sizeof(struct virtnet_info));
 491         if (!dev)
 492                 return -ENOMEM;
 493
 494         /* Set up network device as normal. */
 495         dev->open = virtnet_open;
 496         dev->stop = virtnet_close;
 497         dev->hard_start_xmit = start_xmit;
 498         dev->features = NETIF_F_HIGHDMA;
 499 #ifdef CONFIG_NET_POLL_CONTROLLER
 500         dev->poll_controller = virtnet_netpoll;
 501 #endif
 502         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
 503         SET_NETDEV_DEV(dev, &vdev->dev);
 504
 505         /* Do we support "hardware" checksums? */
 506         if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
 507                 /* This opens up the world of extra features. */
 508                 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
 509                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
 510                         dev->features |= NETIF_F_TSO | NETIF_F_UFO
 511                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
 512                 }
 513                 /* Individual feature bits: what can host handle? */
 514                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
 515                         dev->features |= NETIF_F_TSO;
 516                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
 517                         dev->features |= NETIF_F_TSO6;
 518                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
 519                         dev->features |= NETIF_F_TSO_ECN;
 520                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
 521                         dev->features |= NETIF_F_UFO;
 522         }
 523
 524         /* Configuration may specify what MAC to use.  Otherwise random. */
 525         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
 526                 vdev->config->get(vdev,
 527                                   offsetof(struct virtio_net_config, mac),
 528                                   dev->dev_addr, dev->addr_len);
 529         } else
 530                 random_ether_addr(dev->dev_addr);
 531
 532         /* Set up our device-specific information */
 533         vi = netdev_priv(dev);
 534         netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
 535         vi->dev = dev;
 536         vi->vdev = vdev;
 537         vdev->priv = vi;
 538         vi->pages = NULL;
 539
 540         /* If they give us a callback when all buffers are done, we don't need
 541          * the timer. */
 542         vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY);
 543
 544         /* If we can receive ANY GSO packets, we must allocate large ones. */
 545         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4)
 546             || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)
 547             || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
 548                 vi->big_packets = true;
 549
 550         /* We expect two virtqueues, receive then send. */
 551         vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
 552         if (IS_ERR(vi->rvq)) {
 553                 err = PTR_ERR(vi->rvq);
 554                 goto free;
 555         }
 556
 557         vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done);
 558         if (IS_ERR(vi->svq)) {
 559                 err = PTR_ERR(vi->svq);
 560                 goto free_recv;
 561         }
 562
 563         /* Initialize our empty receive and send queues. */
 564         skb_queue_head_init(&vi->recv);
 565         skb_queue_head_init(&vi->send);
 566
 567         tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi);
 568
 569         if (!vi->free_in_tasklet)
 570                 setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi);
 571
 572         err = register_netdev(dev);
 573         if (err) {
 574                 pr_debug("virtio_net: registering device failed\n");
 575                 goto free_send;
 576         }
 577
 578         /* Last of all, set up some receive buffers. */
 579         try_fill_recv(vi);
 580
 581         /* If we didn't even get one input buffer, we're useless. */
 582         if (vi->num == 0) {
 583                 err = -ENOMEM;
 584                 goto unregister;
 585         }
 586
 587         pr_debug("virtnet: registered device %s\n", dev->name);
 588         return 0;
 589
 590 unregister:
 591         unregister_netdev(dev);
 592 free_send:
 593         vdev->config->del_vq(vi->svq);
 594 free_recv:
 595         vdev->config->del_vq(vi->rvq);
 596 free:
 597         free_netdev(dev);
 598         return err;
 599 }
 600
 601 static void virtnet_remove(struct virtio_device *vdev)
 602 {
 603         struct virtnet_info *vi = vdev->priv;
 604         struct sk_buff *skb;
 605
 606         /* Stop all the virtqueues. */
 607         vdev->config->reset(vdev);
 608
 609         if (!vi->free_in_tasklet)
 610                 del_timer_sync(&vi->xmit_free_timer);
 611
 612         /* Free our skbs in send and recv queues, if any. */
 613         while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
 614                 kfree_skb(skb);
 615                 vi->num--;
 616         }
 617         __skb_queue_purge(&vi->send);
 618
 619         BUG_ON(vi->num != 0);
 620
 621         vdev->config->del_vq(vi->svq);
 622         vdev->config->del_vq(vi->rvq);
 623         unregister_netdev(vi->dev);
 624
 625         while (vi->pages)
 626                 __free_pages(get_a_page(vi, GFP_KERNEL), 0);
 627
 628         free_netdev(vi->dev);
 629 }
 630
 631 static struct virtio_device_id id_table[] = {
 632         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
 633         { 0 },
 634 };
 635
 636 static unsigned int features[] = {
 637         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
 638         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
 639         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
 640         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
 641         VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */
 642         VIRTIO_F_NOTIFY_ON_EMPTY,
 643 };
 644
 645 static struct virtio_driver virtio_net = {
 646         .feature_table = features,
 647         .feature_table_size = ARRAY_SIZE(features),
 648         .driver.name =  KBUILD_MODNAME,
 649         .driver.owner = THIS_MODULE,
 650         .id_table =     id_table,
 651         .probe =        virtnet_probe,
 652         .remove =       __devexit_p(virtnet_remove),
 653 };
 654
 655 static int __init init(void)
 656 {
 657         return register_virtio_driver(&virtio_net);
 658 }
 659
 660 static void __exit fini(void)
 661 {
 662         unregister_virtio_driver(&virtio_net);
 663 }
 664 module_init(init);
 665 module_exit(fini);
 666
 667 MODULE_DEVICE_TABLE(virtio, id_table);
 668 MODULE_DESCRIPTION("Virtio network driver");
 669 MODULE_LICENSE("GPL");