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