drivers/net/virtio_net.c

   1 /* A 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 #include <linux/if_vlan.h>
  28 #include <linux/slab.h>
  29
  30 static int napi_weight = 128;
  31 module_param(napi_weight, int, 0444);
  32
  33 static bool csum = true, gso = true;
  34 module_param(csum, bool, 0444);
  35 module_param(gso, bool, 0444);
  36
  37 /* FIXME: MTU in config. */
  38 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  39 #define GOOD_COPY_LEN   128
  40
  41 #define VIRTNET_SEND_COMMAND_SG_MAX    2
  42 #define VIRTNET_DRIVER_VERSION "1.0.0"
  43
  44 struct virtnet_stats {
  45         struct u64_stats_sync tx_syncp;
  46         struct u64_stats_sync rx_syncp;
  47         u64 tx_bytes;
  48         u64 tx_packets;
  49
  50         u64 rx_bytes;
  51         u64 rx_packets;
  52 };
  53
  54 struct virtnet_info {
  55         struct virtio_device *vdev;
  56         struct virtqueue *rvq, *svq, *cvq;
  57         struct net_device *dev;
  58         struct napi_struct napi;
  59         unsigned int status;
  60
  61         /* Number of input buffers, and max we've ever had. */
  62         unsigned int num, max;
  63
  64         /* I like... big packets and I cannot lie! */
  65         bool big_packets;
  66
  67         /* Host will merge rx buffers for big packets (shake it! shake it!) */
  68         bool mergeable_rx_bufs;
  69
  70         /* enable config space updates */
  71         bool config_enable;
  72
  73         /* Active statistics */
  74         struct virtnet_stats __percpu *stats;
  75
  76         /* Work struct for refilling if we run low on memory. */
  77         struct delayed_work refill;
  78
  79         /* Work struct for config space updates */
  80         struct work_struct config_work;
  81
  82         /* Lock for config space updates */
  83         struct mutex config_lock;
  84
  85         /* Chain pages by the private ptr. */
  86         struct page *pages;
  87
  88         /* fragments + linear part + virtio header */
  89         struct scatterlist rx_sg[MAX_SKB_FRAGS + 2];
  90         struct scatterlist tx_sg[MAX_SKB_FRAGS + 2];
  91 };
  92
  93 struct skb_vnet_hdr {
  94         union {
  95                 struct virtio_net_hdr hdr;
  96                 struct virtio_net_hdr_mrg_rxbuf mhdr;
  97         };
  98 };
  99
 100 struct padded_vnet_hdr {
 101         struct virtio_net_hdr hdr;
 102         /*
 103          * virtio_net_hdr should be in a separated sg buffer because of a
 104          * QEMU bug, and data sg buffer shares same page with this header sg.
 105          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
 106          */
 107         char padding[6];
 108 };
 109
 110 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
 111 {
 112         return (struct skb_vnet_hdr *)skb->cb;
 113 }
 114
 115 /*
 116  * private is used to chain pages for big packets, put the whole
 117  * most recent used list in the beginning for reuse
 118  */
 119 static void give_pages(struct virtnet_info *vi, struct page *page)
 120 {
 121         struct page *end;
 122
 123         /* Find end of list, sew whole thing into vi->pages. */
 124         for (end = page; end->private; end = (struct page *)end->private);
 125         end->private = (unsigned long)vi->pages;
 126         vi->pages = page;
 127 }
 128
 129 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
 130 {
 131         struct page *p = vi->pages;
 132
 133         if (p) {
 134                 vi->pages = (struct page *)p->private;
 135                 /* clear private here, it is used to chain pages */
 136                 p->private = 0;
 137         } else
 138                 p = alloc_page(gfp_mask);
 139         return p;
 140 }
 141
 142 static void skb_xmit_done(struct virtqueue *svq)
 143 {
 144         struct virtnet_info *vi = svq->vdev->priv;
 145
 146         /* Suppress further interrupts. */
 147         virtqueue_disable_cb(svq);
 148
 149         /* We were probably waiting for more output buffers. */
 150         netif_wake_queue(vi->dev);
 151 }
 152
 153 static void set_skb_frag(struct sk_buff *skb, struct page *page,
 154                          unsigned int offset, unsigned int *len)
 155 {
 156         int size = min((unsigned)PAGE_SIZE - offset, *len);
 157         int i = skb_shinfo(skb)->nr_frags;
 158
 159         __skb_fill_page_desc(skb, i, page, offset, size);
 160
 161         skb->data_len += size;
 162         skb->len += size;
 163         skb->truesize += PAGE_SIZE;
 164         skb_shinfo(skb)->nr_frags++;
 165         *len -= size;
 166 }
 167
 168 /* Called from bottom half context */
 169 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 170                                    struct page *page, unsigned int len)
 171 {
 172         struct sk_buff *skb;
 173         struct skb_vnet_hdr *hdr;
 174         unsigned int copy, hdr_len, offset;
 175         char *p;
 176
 177         p = page_address(page);
 178
 179         /* copy small packet so we can reuse these pages for small data */
 180         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
 181         if (unlikely(!skb))
 182                 return NULL;
 183
 184         hdr = skb_vnet_hdr(skb);
 185
 186         if (vi->mergeable_rx_bufs) {
 187                 hdr_len = sizeof hdr->mhdr;
 188                 offset = hdr_len;
 189         } else {
 190                 hdr_len = sizeof hdr->hdr;
 191                 offset = sizeof(struct padded_vnet_hdr);
 192         }
 193
 194         memcpy(hdr, p, hdr_len);
 195
 196         len -= hdr_len;
 197         p += offset;
 198
 199         copy = len;
 200         if (copy > skb_tailroom(skb))
 201                 copy = skb_tailroom(skb);
 202         memcpy(skb_put(skb, copy), p, copy);
 203
 204         len -= copy;
 205         offset += copy;
 206
 207         /*
 208          * Verify that we can indeed put this data into a skb.
 209          * This is here to handle cases when the device erroneously
 210          * tries to receive more than is possible. This is usually
 211          * the case of a broken device.
 212          */
 213         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 214                 if (net_ratelimit())
 215                         pr_debug("%s: too much data\n", skb->dev->name);
 216                 dev_kfree_skb(skb);
 217                 return NULL;
 218         }
 219
 220         while (len) {
 221                 set_skb_frag(skb, page, offset, &len);
 222                 page = (struct page *)page->private;
 223                 offset = 0;
 224         }
 225
 226         if (page)
 227                 give_pages(vi, page);
 228
 229         return skb;
 230 }
 231
 232 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
 233 {
 234         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 235         struct page *page;
 236         int num_buf, i, len;
 237
 238         num_buf = hdr->mhdr.num_buffers;
 239         while (--num_buf) {
 240                 i = skb_shinfo(skb)->nr_frags;
 241                 if (i >= MAX_SKB_FRAGS) {
 242                         pr_debug("%s: packet too long\n", skb->dev->name);
 243                         skb->dev->stats.rx_length_errors++;
 244                         return -EINVAL;
 245                 }
 246                 page = virtqueue_get_buf(vi->rvq, &len);
 247                 if (!page) {
 248                         pr_debug("%s: rx error: %d buffers missing\n",
 249                                  skb->dev->name, hdr->mhdr.num_buffers);
 250                         skb->dev->stats.rx_length_errors++;
 251                         return -EINVAL;
 252                 }
 253
 254                 if (len > PAGE_SIZE)
 255                         len = PAGE_SIZE;
 256
 257                 set_skb_frag(skb, page, 0, &len);
 258
 259                 --vi->num;
 260         }
 261         return 0;
 262 }
 263
 264 static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
 265 {
 266         struct virtnet_info *vi = netdev_priv(dev);
 267         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 268         struct sk_buff *skb;
 269         struct page *page;
 270         struct skb_vnet_hdr *hdr;
 271
 272         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
 273                 pr_debug("%s: short packet %i\n", dev->name, len);
 274                 dev->stats.rx_length_errors++;
 275                 if (vi->mergeable_rx_bufs || vi->big_packets)
 276                         give_pages(vi, buf);
 277                 else
 278                         dev_kfree_skb(buf);
 279                 return;
 280         }
 281
 282         if (!vi->mergeable_rx_bufs && !vi->big_packets) {
 283                 skb = buf;
 284                 len -= sizeof(struct virtio_net_hdr);
 285                 skb_trim(skb, len);
 286         } else {
 287                 page = buf;
 288                 skb = page_to_skb(vi, page, len);
 289                 if (unlikely(!skb)) {
 290                         dev->stats.rx_dropped++;
 291                         give_pages(vi, page);
 292                         return;
 293                 }
 294                 if (vi->mergeable_rx_bufs)
 295                         if (receive_mergeable(vi, skb)) {
 296                                 dev_kfree_skb(skb);
 297                                 return;
 298                         }
 299         }
 300
 301         hdr = skb_vnet_hdr(skb);
 302
 303         u64_stats_update_begin(&stats->rx_syncp);
 304         stats->rx_bytes += skb->len;
 305         stats->rx_packets++;
 306         u64_stats_update_end(&stats->rx_syncp);
 307
 308         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 309                 pr_debug("Needs csum!\n");
 310                 if (!skb_partial_csum_set(skb,
 311                                           hdr->hdr.csum_start,
 312                                           hdr->hdr.csum_offset))
 313                         goto frame_err;
 314         } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
 315                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 316         }
 317
 318         skb->protocol = eth_type_trans(skb, dev);
 319         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 320                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 321
 322         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 323                 pr_debug("GSO!\n");
 324                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 325                 case VIRTIO_NET_HDR_GSO_TCPV4:
 326                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 327                         break;
 328                 case VIRTIO_NET_HDR_GSO_UDP:
 329                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 330                         break;
 331                 case VIRTIO_NET_HDR_GSO_TCPV6:
 332                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 333                         break;
 334                 default:
 335                         if (net_ratelimit())
 336                                 printk(KERN_WARNING "%s: bad gso type %u.\n",
 337                                        dev->name, hdr->hdr.gso_type);
 338                         goto frame_err;
 339                 }
 340
 341                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 342                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 343
 344                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
 345                 if (skb_shinfo(skb)->gso_size == 0) {
 346                         if (net_ratelimit())
 347                                 printk(KERN_WARNING "%s: zero gso size.\n",
 348                                        dev->name);
 349                         goto frame_err;
 350                 }
 351
 352                 /* Header must be checked, and gso_segs computed. */
 353                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 354                 skb_shinfo(skb)->gso_segs = 0;
 355         }
 356
 357         netif_receive_skb(skb);
 358         return;
 359
 360 frame_err:
 361         dev->stats.rx_frame_errors++;
 362         dev_kfree_skb(skb);
 363 }
 364
 365 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
 366 {
 367         struct sk_buff *skb;
 368         struct skb_vnet_hdr *hdr;
 369         int err;
 370
 371         skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp);
 372         if (unlikely(!skb))
 373                 return -ENOMEM;
 374
 375         skb_put(skb, MAX_PACKET_LEN);
 376
 377         hdr = skb_vnet_hdr(skb);
 378         sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr);
 379
 380         skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len);
 381
 382         err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 2, skb, gfp);
 383         if (err < 0)
 384                 dev_kfree_skb(skb);
 385
 386         return err;
 387 }
 388
 389 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
 390 {
 391         struct page *first, *list = NULL;
 392         char *p;
 393         int i, err, offset;
 394
 395         /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */
 396         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 397                 first = get_a_page(vi, gfp);
 398                 if (!first) {
 399                         if (list)
 400                                 give_pages(vi, list);
 401                         return -ENOMEM;
 402                 }
 403                 sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE);
 404
 405                 /* chain new page in list head to match sg */
 406                 first->private = (unsigned long)list;
 407                 list = first;
 408         }
 409
 410         first = get_a_page(vi, gfp);
 411         if (!first) {
 412                 give_pages(vi, list);
 413                 return -ENOMEM;
 414         }
 415         p = page_address(first);
 416
 417         /* vi->rx_sg[0], vi->rx_sg[1] share the same page */
 418         /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */
 419         sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr));
 420
 421         /* vi->rx_sg[1] for data packet, from offset */
 422         offset = sizeof(struct padded_vnet_hdr);
 423         sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset);
 424
 425         /* chain first in list head */
 426         first->private = (unsigned long)list;
 427         err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2,
 428                                 first, gfp);
 429         if (err < 0)
 430                 give_pages(vi, first);
 431
 432         return err;
 433 }
 434
 435 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
 436 {
 437         struct page *page;
 438         int err;
 439
 440         page = get_a_page(vi, gfp);
 441         if (!page)
 442                 return -ENOMEM;
 443
 444         sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE);
 445
 446         err = virtqueue_add_buf(vi->rvq, vi->rx_sg, 0, 1, page, gfp);
 447         if (err < 0)
 448                 give_pages(vi, page);
 449
 450         return err;
 451 }
 452
 453 /*
 454  * Returns false if we couldn't fill entirely (OOM).
 455  *
 456  * Normally run in the receive path, but can also be run from ndo_open
 457  * before we're receiving packets, or from refill_work which is
 458  * careful to disable receiving (using napi_disable).
 459  */
 460 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
 461 {
 462         int err;
 463         bool oom;
 464
 465         do {
 466                 if (vi->mergeable_rx_bufs)
 467                         err = add_recvbuf_mergeable(vi, gfp);
 468                 else if (vi->big_packets)
 469                         err = add_recvbuf_big(vi, gfp);
 470                 else
 471                         err = add_recvbuf_small(vi, gfp);
 472
 473                 oom = err == -ENOMEM;
 474                 if (err)
 475                         break;
 476                 ++vi->num;
 477         } while (vi->rvq->num_free);
 478
 479         if (unlikely(vi->num > vi->max))
 480                 vi->max = vi->num;
 481         virtqueue_kick(vi->rvq);
 482         return !oom;
 483 }
 484
 485 static void skb_recv_done(struct virtqueue *rvq)
 486 {
 487         struct virtnet_info *vi = rvq->vdev->priv;
 488         /* Schedule NAPI, Suppress further interrupts if successful. */
 489         if (napi_schedule_prep(&vi->napi)) {
 490                 virtqueue_disable_cb(rvq);
 491                 __napi_schedule(&vi->napi);
 492         }
 493 }
 494
 495 static void virtnet_napi_enable(struct virtnet_info *vi)
 496 {
 497         napi_enable(&vi->napi);
 498
 499         /* If all buffers were filled by other side before we napi_enabled, we
 500          * won't get another interrupt, so process any outstanding packets
 501          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 502          * We synchronize against interrupts via NAPI_STATE_SCHED */
 503         if (napi_schedule_prep(&vi->napi)) {
 504                 virtqueue_disable_cb(vi->rvq);
 505                 local_bh_disable();
 506                 __napi_schedule(&vi->napi);
 507                 local_bh_enable();
 508         }
 509 }
 510
 511 static void refill_work(struct work_struct *work)
 512 {
 513         struct virtnet_info *vi;
 514         bool still_empty;
 515
 516         vi = container_of(work, struct virtnet_info, refill.work);
 517         napi_disable(&vi->napi);
 518         still_empty = !try_fill_recv(vi, GFP_KERNEL);
 519         virtnet_napi_enable(vi);
 520
 521         /* In theory, this can happen: if we don't get any buffers in
 522          * we will *never* try to fill again. */
 523         if (still_empty)
 524                 schedule_delayed_work(&vi->refill, HZ/2);
 525 }
 526
 527 static int virtnet_poll(struct napi_struct *napi, int budget)
 528 {
 529         struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
 530         void *buf;
 531         unsigned int len, received = 0;
 532
 533 again:
 534         while (received < budget &&
 535                (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) {
 536                 receive_buf(vi->dev, buf, len);
 537                 --vi->num;
 538                 received++;
 539         }
 540
 541         if (vi->num < vi->max / 2) {
 542                 if (!try_fill_recv(vi, GFP_ATOMIC))
 543                         schedule_delayed_work(&vi->refill, 0);
 544         }
 545
 546         /* Out of packets? */
 547         if (received < budget) {
 548                 napi_complete(napi);
 549                 if (unlikely(!virtqueue_enable_cb(vi->rvq)) &&
 550                     napi_schedule_prep(napi)) {
 551                         virtqueue_disable_cb(vi->rvq);
 552                         __napi_schedule(napi);
 553                         goto again;
 554                 }
 555         }
 556
 557         return received;
 558 }
 559
 560 static void free_old_xmit_skbs(struct virtnet_info *vi)
 561 {
 562         struct sk_buff *skb;
 563         unsigned int len;
 564         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 565
 566         while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
 567                 pr_debug("Sent skb %p\n", skb);
 568
 569                 u64_stats_update_begin(&stats->tx_syncp);
 570                 stats->tx_bytes += skb->len;
 571                 stats->tx_packets++;
 572                 u64_stats_update_end(&stats->tx_syncp);
 573
 574                 dev_kfree_skb_any(skb);
 575         }
 576 }
 577
 578 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
 579 {
 580         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 581         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 582         unsigned num_sg;
 583
 584         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 585
 586         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 587                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 588                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
 589                 hdr->hdr.csum_offset = skb->csum_offset;
 590         } else {
 591                 hdr->hdr.flags = 0;
 592                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 593         }
 594
 595         if (skb_is_gso(skb)) {
 596                 hdr->hdr.hdr_len = skb_headlen(skb);
 597                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
 598                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 599                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 600                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 601                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 602                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 603                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 604                 else
 605                         BUG();
 606                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 607                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 608         } else {
 609                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 610                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
 611         }
 612
 613         hdr->mhdr.num_buffers = 0;
 614
 615         /* Encode metadata header at front. */
 616         if (vi->mergeable_rx_bufs)
 617                 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr);
 618         else
 619                 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr);
 620
 621         num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1;
 622         return virtqueue_add_buf(vi->svq, vi->tx_sg, num_sg,
 623                                  0, skb, GFP_ATOMIC);
 624 }
 625
 626 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 627 {
 628         struct virtnet_info *vi = netdev_priv(dev);
 629         int err;
 630
 631         /* Free up any pending old buffers before queueing new ones. */
 632         free_old_xmit_skbs(vi);
 633
 634         /* Try to transmit */
 635         err = xmit_skb(vi, skb);
 636
 637         /* This should not happen! */
 638         if (unlikely(err)) {
 639                 dev->stats.tx_fifo_errors++;
 640                 if (net_ratelimit())
 641                         dev_warn(&dev->dev,
 642                                  "Unexpected TX queue failure: %d\n", err);
 643                 dev->stats.tx_dropped++;
 644                 kfree_skb(skb);
 645                 return NETDEV_TX_OK;
 646         }
 647         virtqueue_kick(vi->svq);
 648
 649         /* Don't wait up for transmitted skbs to be freed. */
 650         skb_orphan(skb);
 651         nf_reset(skb);
 652
 653         /* Apparently nice girls don't return TX_BUSY; stop the queue
 654          * before it gets out of hand.  Naturally, this wastes entries. */
 655         if (vi->svq->num_free < 2+MAX_SKB_FRAGS) {
 656                 netif_stop_queue(dev);
 657                 if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) {
 658                         /* More just got used, free them then recheck. */
 659                         free_old_xmit_skbs(vi);
 660                         if (vi->svq->num_free >= 2+MAX_SKB_FRAGS) {
 661                                 netif_start_queue(dev);
 662                                 virtqueue_disable_cb(vi->svq);
 663                         }
 664                 }
 665         }
 666
 667         return NETDEV_TX_OK;
 668 }
 669
 670 static int virtnet_set_mac_address(struct net_device *dev, void *p)
 671 {
 672         struct virtnet_info *vi = netdev_priv(dev);
 673         struct virtio_device *vdev = vi->vdev;
 674         int ret;
 675
 676         ret = eth_mac_addr(dev, p);
 677         if (ret)
 678                 return ret;
 679
 680         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
 681                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
 682                                   dev->dev_addr, dev->addr_len);
 683
 684         return 0;
 685 }
 686
 687 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
 688                                                struct rtnl_link_stats64 *tot)
 689 {
 690         struct virtnet_info *vi = netdev_priv(dev);
 691         int cpu;
 692         unsigned int start;
 693
 694         for_each_possible_cpu(cpu) {
 695                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
 696                 u64 tpackets, tbytes, rpackets, rbytes;
 697
 698                 do {
 699                         start = u64_stats_fetch_begin_bh(&stats->tx_syncp);
 700                         tpackets = stats->tx_packets;
 701                         tbytes   = stats->tx_bytes;
 702                 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start));
 703
 704                 do {
 705                         start = u64_stats_fetch_begin_bh(&stats->rx_syncp);
 706                         rpackets = stats->rx_packets;
 707                         rbytes   = stats->rx_bytes;
 708                 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start));
 709
 710                 tot->rx_packets += rpackets;
 711                 tot->tx_packets += tpackets;
 712                 tot->rx_bytes   += rbytes;
 713                 tot->tx_bytes   += tbytes;
 714         }
 715
 716         tot->tx_dropped = dev->stats.tx_dropped;
 717         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
 718         tot->rx_dropped = dev->stats.rx_dropped;
 719         tot->rx_length_errors = dev->stats.rx_length_errors;
 720         tot->rx_frame_errors = dev->stats.rx_frame_errors;
 721
 722         return tot;
 723 }
 724
 725 #ifdef CONFIG_NET_POLL_CONTROLLER
 726 static void virtnet_netpoll(struct net_device *dev)
 727 {
 728         struct virtnet_info *vi = netdev_priv(dev);
 729
 730         napi_schedule(&vi->napi);
 731 }
 732 #endif
 733
 734 static int virtnet_open(struct net_device *dev)
 735 {
 736         struct virtnet_info *vi = netdev_priv(dev);
 737
 738         /* Make sure we have some buffers: if oom use wq. */
 739         if (!try_fill_recv(vi, GFP_KERNEL))
 740                 schedule_delayed_work(&vi->refill, 0);
 741
 742         virtnet_napi_enable(vi);
 743         return 0;
 744 }
 745
 746 /*
 747  * Send command via the control virtqueue and check status.  Commands
 748  * supported by the hypervisor, as indicated by feature bits, should
 749  * never fail unless improperly formated.
 750  */
 751 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 752                                  struct scatterlist *data, int out, int in)
 753 {
 754         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
 755         struct virtio_net_ctrl_hdr ctrl;
 756         virtio_net_ctrl_ack status = ~0;
 757         unsigned int tmp;
 758         int i;
 759
 760         /* Caller should know better */
 761         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
 762                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
 763
 764         out++; /* Add header */
 765         in++; /* Add return status */
 766
 767         ctrl.class = class;
 768         ctrl.cmd = cmd;
 769
 770         sg_init_table(sg, out + in);
 771
 772         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
 773         for_each_sg(data, s, out + in - 2, i)
 774                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
 775         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
 776
 777         BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0);
 778
 779         virtqueue_kick(vi->cvq);
 780
 781         /*
 782          * Spin for a response, the kick causes an ioport write, trapping
 783          * into the hypervisor, so the request should be handled immediately.
 784          */
 785         while (!virtqueue_get_buf(vi->cvq, &tmp))
 786                 cpu_relax();
 787
 788         return status == VIRTIO_NET_OK;
 789 }
 790
 791 static void virtnet_ack_link_announce(struct virtnet_info *vi)
 792 {
 793         rtnl_lock();
 794         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
 795                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL,
 796                                   0, 0))
 797                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
 798         rtnl_unlock();
 799 }
 800
 801 static int virtnet_close(struct net_device *dev)
 802 {
 803         struct virtnet_info *vi = netdev_priv(dev);
 804
 805         /* Make sure refill_work doesn't re-enable napi! */
 806         cancel_delayed_work_sync(&vi->refill);
 807         napi_disable(&vi->napi);
 808
 809         return 0;
 810 }
 811
 812 static void virtnet_set_rx_mode(struct net_device *dev)
 813 {
 814         struct virtnet_info *vi = netdev_priv(dev);
 815         struct scatterlist sg[2];
 816         u8 promisc, allmulti;
 817         struct virtio_net_ctrl_mac *mac_data;
 818         struct netdev_hw_addr *ha;
 819         int uc_count;
 820         int mc_count;
 821         void *buf;
 822         int i;
 823
 824         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
 825         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
 826                 return;
 827
 828         promisc = ((dev->flags & IFF_PROMISC) != 0);
 829         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
 830
 831         sg_init_one(sg, &promisc, sizeof(promisc));
 832
 833         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 834                                   VIRTIO_NET_CTRL_RX_PROMISC,
 835                                   sg, 1, 0))
 836                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
 837                          promisc ? "en" : "dis");
 838
 839         sg_init_one(sg, &allmulti, sizeof(allmulti));
 840
 841         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 842                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
 843                                   sg, 1, 0))
 844                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
 845                          allmulti ? "en" : "dis");
 846
 847         uc_count = netdev_uc_count(dev);
 848         mc_count = netdev_mc_count(dev);
 849         /* MAC filter - use one buffer for both lists */
 850         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
 851                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
 852         mac_data = buf;
 853         if (!buf) {
 854                 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
 855                 return;
 856         }
 857
 858         sg_init_table(sg, 2);
 859
 860         /* Store the unicast list and count in the front of the buffer */
 861         mac_data->entries = uc_count;
 862         i = 0;
 863         netdev_for_each_uc_addr(ha, dev)
 864                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 865
 866         sg_set_buf(&sg[0], mac_data,
 867                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
 868
 869         /* multicast list and count fill the end */
 870         mac_data = (void *)&mac_data->macs[uc_count][0];
 871
 872         mac_data->entries = mc_count;
 873         i = 0;
 874         netdev_for_each_mc_addr(ha, dev)
 875                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 876
 877         sg_set_buf(&sg[1], mac_data,
 878                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
 879
 880         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
 881                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
 882                                   sg, 2, 0))
 883                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
 884
 885         kfree(buf);
 886 }
 887
 888 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
 889 {
 890         struct virtnet_info *vi = netdev_priv(dev);
 891         struct scatterlist sg;
 892
 893         sg_init_one(&sg, &vid, sizeof(vid));
 894
 895         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
 896                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
 897                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
 898         return 0;
 899 }
 900
 901 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
 902 {
 903         struct virtnet_info *vi = netdev_priv(dev);
 904         struct scatterlist sg;
 905
 906         sg_init_one(&sg, &vid, sizeof(vid));
 907
 908         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
 909                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
 910                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
 911         return 0;
 912 }
 913
 914 static void virtnet_get_ringparam(struct net_device *dev,
 915                                 struct ethtool_ringparam *ring)
 916 {
 917         struct virtnet_info *vi = netdev_priv(dev);
 918
 919         ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq);
 920         ring->tx_max_pending = virtqueue_get_vring_size(vi->svq);
 921         ring->rx_pending = ring->rx_max_pending;
 922         ring->tx_pending = ring->tx_max_pending;
 923
 924 }
 925
 926
 927 static void virtnet_get_drvinfo(struct net_device *dev,
 928                                 struct ethtool_drvinfo *info)
 929 {
 930         struct virtnet_info *vi = netdev_priv(dev);
 931         struct virtio_device *vdev = vi->vdev;
 932
 933         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
 934         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
 935         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
 936
 937 }
 938
 939 static const struct ethtool_ops virtnet_ethtool_ops = {
 940         .get_drvinfo = virtnet_get_drvinfo,
 941         .get_link = ethtool_op_get_link,
 942         .get_ringparam = virtnet_get_ringparam,
 943 };
 944
 945 #define MIN_MTU 68
 946 #define MAX_MTU 65535
 947
 948 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
 949 {
 950         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
 951                 return -EINVAL;
 952         dev->mtu = new_mtu;
 953         return 0;
 954 }
 955
 956 static const struct net_device_ops virtnet_netdev = {
 957         .ndo_open            = virtnet_open,
 958         .ndo_stop            = virtnet_close,
 959         .ndo_start_xmit      = start_xmit,
 960         .ndo_validate_addr   = eth_validate_addr,
 961         .ndo_set_mac_address = virtnet_set_mac_address,
 962         .ndo_set_rx_mode     = virtnet_set_rx_mode,
 963         .ndo_change_mtu      = virtnet_change_mtu,
 964         .ndo_get_stats64     = virtnet_stats,
 965         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
 966         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
 967 #ifdef CONFIG_NET_POLL_CONTROLLER
 968         .ndo_poll_controller = virtnet_netpoll,
 969 #endif
 970 };
 971
 972 static void virtnet_config_changed_work(struct work_struct *work)
 973 {
 974         struct virtnet_info *vi =
 975                 container_of(work, struct virtnet_info, config_work);
 976         u16 v;
 977
 978         mutex_lock(&vi->config_lock);
 979         if (!vi->config_enable)
 980                 goto done;
 981
 982         if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
 983                               offsetof(struct virtio_net_config, status),
 984                               &v) < 0)
 985                 goto done;
 986
 987         if (v & VIRTIO_NET_S_ANNOUNCE) {
 988                 netdev_notify_peers(vi->dev);
 989                 virtnet_ack_link_announce(vi);
 990         }
 991
 992         /* Ignore unknown (future) status bits */
 993         v &= VIRTIO_NET_S_LINK_UP;
 994
 995         if (vi->status == v)
 996                 goto done;
 997
 998         vi->status = v;
 999
1000         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1001                 netif_carrier_on(vi->dev);
1002                 netif_wake_queue(vi->dev);
1003         } else {
1004                 netif_carrier_off(vi->dev);
1005                 netif_stop_queue(vi->dev);
1006         }
1007 done:
1008         mutex_unlock(&vi->config_lock);
1009 }
1010
1011 static void virtnet_config_changed(struct virtio_device *vdev)
1012 {
1013         struct virtnet_info *vi = vdev->priv;
1014
1015         schedule_work(&vi->config_work);
1016 }
1017
1018 static int init_vqs(struct virtnet_info *vi)
1019 {
1020         struct virtqueue *vqs[3];
1021         vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
1022         const char *names[] = { "input", "output", "control" };
1023         int nvqs, err;
1024
1025         /* We expect two virtqueues, receive then send,
1026          * and optionally control. */
1027         nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
1028
1029         err = vi->vdev->config->find_vqs(vi->vdev, nvqs, vqs, callbacks, names);
1030         if (err)
1031                 return err;
1032
1033         vi->rvq = vqs[0];
1034         vi->svq = vqs[1];
1035
1036         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
1037                 vi->cvq = vqs[2];
1038
1039                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1040                         vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
1041         }
1042         return 0;
1043 }
1044
1045 static int virtnet_probe(struct virtio_device *vdev)
1046 {
1047         int err;
1048         struct net_device *dev;
1049         struct virtnet_info *vi;
1050
1051         /* Allocate ourselves a network device with room for our info */
1052         dev = alloc_etherdev(sizeof(struct virtnet_info));
1053         if (!dev)
1054                 return -ENOMEM;
1055
1056         /* Set up network device as normal. */
1057         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1058         dev->netdev_ops = &virtnet_netdev;
1059         dev->features = NETIF_F_HIGHDMA;
1060
1061         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1062         SET_NETDEV_DEV(dev, &vdev->dev);
1063
1064         /* Do we support "hardware" checksums? */
1065         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1066                 /* This opens up the world of extra features. */
1067                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1068                 if (csum)
1069                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1070
1071                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1072                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1073                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1074                 }
1075                 /* Individual feature bits: what can host handle? */
1076                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1077                         dev->hw_features |= NETIF_F_TSO;
1078                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1079                         dev->hw_features |= NETIF_F_TSO6;
1080                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1081                         dev->hw_features |= NETIF_F_TSO_ECN;
1082                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1083                         dev->hw_features |= NETIF_F_UFO;
1084
1085                 if (gso)
1086                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1087                 /* (!csum && gso) case will be fixed by register_netdev() */
1088         }
1089
1090         /* Configuration may specify what MAC to use.  Otherwise random. */
1091         if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
1092                                   offsetof(struct virtio_net_config, mac),
1093                                   dev->dev_addr, dev->addr_len) < 0)
1094                 eth_hw_addr_random(dev);
1095
1096         /* Set up our device-specific information */
1097         vi = netdev_priv(dev);
1098         netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
1099         vi->dev = dev;
1100         vi->vdev = vdev;
1101         vdev->priv = vi;
1102         vi->pages = NULL;
1103         vi->stats = alloc_percpu(struct virtnet_stats);
1104         err = -ENOMEM;
1105         if (vi->stats == NULL)
1106                 goto free;
1107
1108         INIT_DELAYED_WORK(&vi->refill, refill_work);
1109         mutex_init(&vi->config_lock);
1110         vi->config_enable = true;
1111         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1112         sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg));
1113         sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg));
1114
1115         /* If we can receive ANY GSO packets, we must allocate large ones. */
1116         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1117             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1118             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1119                 vi->big_packets = true;
1120
1121         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1122                 vi->mergeable_rx_bufs = true;
1123
1124         err = init_vqs(vi);
1125         if (err)
1126                 goto free_stats;
1127
1128         err = register_netdev(dev);
1129         if (err) {
1130                 pr_debug("virtio_net: registering device failed\n");
1131                 goto free_vqs;
1132         }
1133
1134         /* Last of all, set up some receive buffers. */
1135         try_fill_recv(vi, GFP_KERNEL);
1136
1137         /* If we didn't even get one input buffer, we're useless. */
1138         if (vi->num == 0) {
1139                 err = -ENOMEM;
1140                 goto unregister;
1141         }
1142
1143         /* Assume link up if device can't report link status,
1144            otherwise get link status from config. */
1145         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1146                 netif_carrier_off(dev);
1147                 schedule_work(&vi->config_work);
1148         } else {
1149                 vi->status = VIRTIO_NET_S_LINK_UP;
1150                 netif_carrier_on(dev);
1151         }
1152
1153         pr_debug("virtnet: registered device %s\n", dev->name);
1154         return 0;
1155
1156 unregister:
1157         unregister_netdev(dev);
1158 free_vqs:
1159         vdev->config->del_vqs(vdev);
1160 free_stats:
1161         free_percpu(vi->stats);
1162 free:
1163         free_netdev(dev);
1164         return err;
1165 }
1166
1167 static void free_unused_bufs(struct virtnet_info *vi)
1168 {
1169         void *buf;
1170         while (1) {
1171                 buf = virtqueue_detach_unused_buf(vi->svq);
1172                 if (!buf)
1173                         break;
1174                 dev_kfree_skb(buf);
1175         }
1176         while (1) {
1177                 buf = virtqueue_detach_unused_buf(vi->rvq);
1178                 if (!buf)
1179                         break;
1180                 if (vi->mergeable_rx_bufs || vi->big_packets)
1181                         give_pages(vi, buf);
1182                 else
1183                         dev_kfree_skb(buf);
1184                 --vi->num;
1185         }
1186         BUG_ON(vi->num != 0);
1187 }
1188
1189 static void remove_vq_common(struct virtnet_info *vi)
1190 {
1191         vi->vdev->config->reset(vi->vdev);
1192
1193         /* Free unused buffers in both send and recv, if any. */
1194         free_unused_bufs(vi);
1195
1196         vi->vdev->config->del_vqs(vi->vdev);
1197
1198         while (vi->pages)
1199                 __free_pages(get_a_page(vi, GFP_KERNEL), 0);
1200 }
1201
1202 static void __devexit virtnet_remove(struct virtio_device *vdev)
1203 {
1204         struct virtnet_info *vi = vdev->priv;
1205
1206         /* Prevent config work handler from accessing the device. */
1207         mutex_lock(&vi->config_lock);
1208         vi->config_enable = false;
1209         mutex_unlock(&vi->config_lock);
1210
1211         unregister_netdev(vi->dev);
1212
1213         remove_vq_common(vi);
1214
1215         flush_work(&vi->config_work);
1216
1217         free_percpu(vi->stats);
1218         free_netdev(vi->dev);
1219 }
1220
1221 #ifdef CONFIG_PM
1222 static int virtnet_freeze(struct virtio_device *vdev)
1223 {
1224         struct virtnet_info *vi = vdev->priv;
1225
1226         /* Prevent config work handler from accessing the device */
1227         mutex_lock(&vi->config_lock);
1228         vi->config_enable = false;
1229         mutex_unlock(&vi->config_lock);
1230
1231         netif_device_detach(vi->dev);
1232         cancel_delayed_work_sync(&vi->refill);
1233
1234         if (netif_running(vi->dev))
1235                 napi_disable(&vi->napi);
1236
1237         remove_vq_common(vi);
1238
1239         flush_work(&vi->config_work);
1240
1241         return 0;
1242 }
1243
1244 static int virtnet_restore(struct virtio_device *vdev)
1245 {
1246         struct virtnet_info *vi = vdev->priv;
1247         int err;
1248
1249         err = init_vqs(vi);
1250         if (err)
1251                 return err;
1252
1253         if (netif_running(vi->dev))
1254                 virtnet_napi_enable(vi);
1255
1256         netif_device_attach(vi->dev);
1257
1258         if (!try_fill_recv(vi, GFP_KERNEL))
1259                 schedule_delayed_work(&vi->refill, 0);
1260
1261         mutex_lock(&vi->config_lock);
1262         vi->config_enable = true;
1263         mutex_unlock(&vi->config_lock);
1264
1265         return 0;
1266 }
1267 #endif
1268
1269 static struct virtio_device_id id_table[] = {
1270         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1271         { 0 },
1272 };
1273
1274 static unsigned int features[] = {
1275         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1276         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1277         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1278         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1279         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1280         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1281         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1282         VIRTIO_NET_F_GUEST_ANNOUNCE,
1283 };
1284
1285 static struct virtio_driver virtio_net_driver = {
1286         .feature_table = features,
1287         .feature_table_size = ARRAY_SIZE(features),
1288         .driver.name =  KBUILD_MODNAME,
1289         .driver.owner = THIS_MODULE,
1290         .id_table =     id_table,
1291         .probe =        virtnet_probe,
1292         .remove =       __devexit_p(virtnet_remove),
1293         .config_changed = virtnet_config_changed,
1294 #ifdef CONFIG_PM
1295         .freeze =       virtnet_freeze,
1296         .restore =      virtnet_restore,
1297 #endif
1298 };
1299
1300 static int __init init(void)
1301 {
1302         return register_virtio_driver(&virtio_net_driver);
1303 }
1304
1305 static void __exit fini(void)
1306 {
1307         unregister_virtio_driver(&virtio_net_driver);
1308 }
1309 module_init(init);
1310 module_exit(fini);
1311
1312 MODULE_DEVICE_TABLE(virtio, id_table);
1313 MODULE_DESCRIPTION("Virtio network driver");
1314 MODULE_LICENSE("GPL");