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 syncp;
  46         u64 tx_bytes;
  47         u64 tx_packets;
  48
  49         u64 rx_bytes;
  50         u64 rx_packets;
  51 };
  52
  53 struct virtnet_info {
  54         struct virtio_device *vdev;
  55         struct virtqueue *rvq, *svq, *cvq;
  56         struct net_device *dev;
  57         struct napi_struct napi;
  58         unsigned int status;
  59
  60         /* Number of input buffers, and max we've ever had. */
  61         unsigned int num, max;
  62
  63         /* I like... big packets and I cannot lie! */
  64         bool big_packets;
  65
  66         /* Host will merge rx buffers for big packets (shake it! shake it!) */
  67         bool mergeable_rx_bufs;
  68
  69         /* enable config space updates */
  70         bool config_enable;
  71
  72         /* Active statistics */
  73         struct virtnet_stats __percpu *stats;
  74
  75         /* Work struct for refilling if we run low on memory. */
  76         struct delayed_work refill;
  77
  78         /* Work struct for config space updates */
  79         struct work_struct config_work;
  80
  81         /* Lock for config space updates */
  82         struct mutex config_lock;
  83
  84         /* Chain pages by the private ptr. */
  85         struct page *pages;
  86
  87         /* fragments + linear part + virtio header */
  88         struct scatterlist rx_sg[MAX_SKB_FRAGS + 2];
  89         struct scatterlist tx_sg[MAX_SKB_FRAGS + 2];
  90 };
  91
  92 struct skb_vnet_hdr {
  93         union {
  94                 struct virtio_net_hdr hdr;
  95                 struct virtio_net_hdr_mrg_rxbuf mhdr;
  96         };
  97         unsigned int num_sg;
  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->syncp);
 304         stats->rx_bytes += skb->len;
 305         stats->rx_packets++;
 306         u64_stats_update_end(&stats->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 < 0)
 475                         break;
 476                 ++vi->num;
 477         } while (err > 0);
 478         if (unlikely(vi->num > vi->max))
 479                 vi->max = vi->num;
 480         virtqueue_kick(vi->rvq);
 481         return !oom;
 482 }
 483
 484 static void skb_recv_done(struct virtqueue *rvq)
 485 {
 486         struct virtnet_info *vi = rvq->vdev->priv;
 487         /* Schedule NAPI, Suppress further interrupts if successful. */
 488         if (napi_schedule_prep(&vi->napi)) {
 489                 virtqueue_disable_cb(rvq);
 490                 __napi_schedule(&vi->napi);
 491         }
 492 }
 493
 494 static void virtnet_napi_enable(struct virtnet_info *vi)
 495 {
 496         napi_enable(&vi->napi);
 497
 498         /* If all buffers were filled by other side before we napi_enabled, we
 499          * won't get another interrupt, so process any outstanding packets
 500          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 501          * We synchronize against interrupts via NAPI_STATE_SCHED */
 502         if (napi_schedule_prep(&vi->napi)) {
 503                 virtqueue_disable_cb(vi->rvq);
 504                 __napi_schedule(&vi->napi);
 505         }
 506 }
 507
 508 static void refill_work(struct work_struct *work)
 509 {
 510         struct virtnet_info *vi;
 511         bool still_empty;
 512
 513         vi = container_of(work, struct virtnet_info, refill.work);
 514         napi_disable(&vi->napi);
 515         still_empty = !try_fill_recv(vi, GFP_KERNEL);
 516         virtnet_napi_enable(vi);
 517
 518         /* In theory, this can happen: if we don't get any buffers in
 519          * we will *never* try to fill again. */
 520         if (still_empty)
 521                 queue_delayed_work(system_nrt_wq, &vi->refill, HZ/2);
 522 }
 523
 524 static int virtnet_poll(struct napi_struct *napi, int budget)
 525 {
 526         struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
 527         void *buf;
 528         unsigned int len, received = 0;
 529
 530 again:
 531         while (received < budget &&
 532                (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) {
 533                 receive_buf(vi->dev, buf, len);
 534                 --vi->num;
 535                 received++;
 536         }
 537
 538         if (vi->num < vi->max / 2) {
 539                 if (!try_fill_recv(vi, GFP_ATOMIC))
 540                         queue_delayed_work(system_nrt_wq, &vi->refill, 0);
 541         }
 542
 543         /* Out of packets? */
 544         if (received < budget) {
 545                 napi_complete(napi);
 546                 if (unlikely(!virtqueue_enable_cb(vi->rvq)) &&
 547                     napi_schedule_prep(napi)) {
 548                         virtqueue_disable_cb(vi->rvq);
 549                         __napi_schedule(napi);
 550                         goto again;
 551                 }
 552         }
 553
 554         return received;
 555 }
 556
 557 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
 558 {
 559         struct sk_buff *skb;
 560         unsigned int len, tot_sgs = 0;
 561         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 562
 563         while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
 564                 pr_debug("Sent skb %p\n", skb);
 565
 566                 u64_stats_update_begin(&stats->syncp);
 567                 stats->tx_bytes += skb->len;
 568                 stats->tx_packets++;
 569                 u64_stats_update_end(&stats->syncp);
 570
 571                 tot_sgs += skb_vnet_hdr(skb)->num_sg;
 572                 dev_kfree_skb_any(skb);
 573         }
 574         return tot_sgs;
 575 }
 576
 577 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
 578 {
 579         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 580         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 581
 582         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 583
 584         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 585                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 586                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
 587                 hdr->hdr.csum_offset = skb->csum_offset;
 588         } else {
 589                 hdr->hdr.flags = 0;
 590                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 591         }
 592
 593         if (skb_is_gso(skb)) {
 594                 hdr->hdr.hdr_len = skb_headlen(skb);
 595                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
 596                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 597                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 598                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 599                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 600                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 601                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 602                 else
 603                         BUG();
 604                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 605                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 606         } else {
 607                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 608                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
 609         }
 610
 611         hdr->mhdr.num_buffers = 0;
 612
 613         /* Encode metadata header at front. */
 614         if (vi->mergeable_rx_bufs)
 615                 sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr);
 616         else
 617                 sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr);
 618
 619         hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1;
 620         return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg,
 621                                  0, skb, GFP_ATOMIC);
 622 }
 623
 624 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 625 {
 626         struct virtnet_info *vi = netdev_priv(dev);
 627         int capacity;
 628
 629         /* Free up any pending old buffers before queueing new ones. */
 630         free_old_xmit_skbs(vi);
 631
 632         /* Try to transmit */
 633         capacity = xmit_skb(vi, skb);
 634
 635         /* This can happen with OOM and indirect buffers. */
 636         if (unlikely(capacity < 0)) {
 637                 if (likely(capacity == -ENOMEM)) {
 638                         if (net_ratelimit())
 639                                 dev_warn(&dev->dev,
 640                                          "TX queue failure: out of memory\n");
 641                 } else {
 642                         dev->stats.tx_fifo_errors++;
 643                         if (net_ratelimit())
 644                                 dev_warn(&dev->dev,
 645                                          "Unexpected TX queue failure: %d\n",
 646                                          capacity);
 647                 }
 648                 dev->stats.tx_dropped++;
 649                 kfree_skb(skb);
 650                 return NETDEV_TX_OK;
 651         }
 652         virtqueue_kick(vi->svq);
 653
 654         /* Don't wait up for transmitted skbs to be freed. */
 655         skb_orphan(skb);
 656         nf_reset(skb);
 657
 658         /* Apparently nice girls don't return TX_BUSY; stop the queue
 659          * before it gets out of hand.  Naturally, this wastes entries. */
 660         if (capacity < 2+MAX_SKB_FRAGS) {
 661                 netif_stop_queue(dev);
 662                 if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) {
 663                         /* More just got used, free them then recheck. */
 664                         capacity += free_old_xmit_skbs(vi);
 665                         if (capacity >= 2+MAX_SKB_FRAGS) {
 666                                 netif_start_queue(dev);
 667                                 virtqueue_disable_cb(vi->svq);
 668                         }
 669                 }
 670         }
 671
 672         return NETDEV_TX_OK;
 673 }
 674
 675 static int virtnet_set_mac_address(struct net_device *dev, void *p)
 676 {
 677         struct virtnet_info *vi = netdev_priv(dev);
 678         struct virtio_device *vdev = vi->vdev;
 679         int ret;
 680
 681         ret = eth_mac_addr(dev, p);
 682         if (ret)
 683                 return ret;
 684
 685         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
 686                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
 687                                   dev->dev_addr, dev->addr_len);
 688
 689         return 0;
 690 }
 691
 692 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
 693                                                struct rtnl_link_stats64 *tot)
 694 {
 695         struct virtnet_info *vi = netdev_priv(dev);
 696         int cpu;
 697         unsigned int start;
 698
 699         for_each_possible_cpu(cpu) {
 700                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
 701                 u64 tpackets, tbytes, rpackets, rbytes;
 702
 703                 do {
 704                         start = u64_stats_fetch_begin(&stats->syncp);
 705                         tpackets = stats->tx_packets;
 706                         tbytes   = stats->tx_bytes;
 707                         rpackets = stats->rx_packets;
 708                         rbytes   = stats->rx_bytes;
 709                 } while (u64_stats_fetch_retry(&stats->syncp, start));
 710
 711                 tot->rx_packets += rpackets;
 712                 tot->tx_packets += tpackets;
 713                 tot->rx_bytes   += rbytes;
 714                 tot->tx_bytes   += tbytes;
 715         }
 716
 717         tot->tx_dropped = dev->stats.tx_dropped;
 718         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
 719         tot->rx_dropped = dev->stats.rx_dropped;
 720         tot->rx_length_errors = dev->stats.rx_length_errors;
 721         tot->rx_frame_errors = dev->stats.rx_frame_errors;
 722
 723         return tot;
 724 }
 725
 726 #ifdef CONFIG_NET_POLL_CONTROLLER
 727 static void virtnet_netpoll(struct net_device *dev)
 728 {
 729         struct virtnet_info *vi = netdev_priv(dev);
 730
 731         napi_schedule(&vi->napi);
 732 }
 733 #endif
 734
 735 static int virtnet_open(struct net_device *dev)
 736 {
 737         struct virtnet_info *vi = netdev_priv(dev);
 738
 739         /* Make sure we have some buffers: if oom use wq. */
 740         if (!try_fill_recv(vi, GFP_KERNEL))
 741                 queue_delayed_work(system_nrt_wq, &vi->refill, 0);
 742
 743         virtnet_napi_enable(vi);
 744         return 0;
 745 }
 746
 747 /*
 748  * Send command via the control virtqueue and check status.  Commands
 749  * supported by the hypervisor, as indicated by feature bits, should
 750  * never fail unless improperly formated.
 751  */
 752 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 753                                  struct scatterlist *data, int out, int in)
 754 {
 755         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
 756         struct virtio_net_ctrl_hdr ctrl;
 757         virtio_net_ctrl_ack status = ~0;
 758         unsigned int tmp;
 759         int i;
 760
 761         /* Caller should know better */
 762         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
 763                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
 764
 765         out++; /* Add header */
 766         in++; /* Add return status */
 767
 768         ctrl.class = class;
 769         ctrl.cmd = cmd;
 770
 771         sg_init_table(sg, out + in);
 772
 773         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
 774         for_each_sg(data, s, out + in - 2, i)
 775                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
 776         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
 777
 778         BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0);
 779
 780         virtqueue_kick(vi->cvq);
 781
 782         /*
 783          * Spin for a response, the kick causes an ioport write, trapping
 784          * into the hypervisor, so the request should be handled immediately.
 785          */
 786         while (!virtqueue_get_buf(vi->cvq, &tmp))
 787                 cpu_relax();
 788
 789         return status == VIRTIO_NET_OK;
 790 }
 791
 792 static void virtnet_ack_link_announce(struct virtnet_info *vi)
 793 {
 794         rtnl_lock();
 795         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
 796                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL,
 797                                   0, 0))
 798                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
 799         rtnl_unlock();
 800 }
 801
 802 static int virtnet_close(struct net_device *dev)
 803 {
 804         struct virtnet_info *vi = netdev_priv(dev);
 805
 806         /* Make sure refill_work doesn't re-enable napi! */
 807         cancel_delayed_work_sync(&vi->refill);
 808         napi_disable(&vi->napi);
 809
 810         return 0;
 811 }
 812
 813 static void virtnet_set_rx_mode(struct net_device *dev)
 814 {
 815         struct virtnet_info *vi = netdev_priv(dev);
 816         struct scatterlist sg[2];
 817         u8 promisc, allmulti;
 818         struct virtio_net_ctrl_mac *mac_data;
 819         struct netdev_hw_addr *ha;
 820         int uc_count;
 821         int mc_count;
 822         void *buf;
 823         int i;
 824
 825         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
 826         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
 827                 return;
 828
 829         promisc = ((dev->flags & IFF_PROMISC) != 0);
 830         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
 831
 832         sg_init_one(sg, &promisc, sizeof(promisc));
 833
 834         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 835                                   VIRTIO_NET_CTRL_RX_PROMISC,
 836                                   sg, 1, 0))
 837                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
 838                          promisc ? "en" : "dis");
 839
 840         sg_init_one(sg, &allmulti, sizeof(allmulti));
 841
 842         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 843                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
 844                                   sg, 1, 0))
 845                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
 846                          allmulti ? "en" : "dis");
 847
 848         uc_count = netdev_uc_count(dev);
 849         mc_count = netdev_mc_count(dev);
 850         /* MAC filter - use one buffer for both lists */
 851         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
 852                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
 853         mac_data = buf;
 854         if (!buf) {
 855                 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
 856                 return;
 857         }
 858
 859         sg_init_table(sg, 2);
 860
 861         /* Store the unicast list and count in the front of the buffer */
 862         mac_data->entries = uc_count;
 863         i = 0;
 864         netdev_for_each_uc_addr(ha, dev)
 865                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 866
 867         sg_set_buf(&sg[0], mac_data,
 868                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
 869
 870         /* multicast list and count fill the end */
 871         mac_data = (void *)&mac_data->macs[uc_count][0];
 872
 873         mac_data->entries = mc_count;
 874         i = 0;
 875         netdev_for_each_mc_addr(ha, dev)
 876                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 877
 878         sg_set_buf(&sg[1], mac_data,
 879                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
 880
 881         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
 882                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
 883                                   sg, 2, 0))
 884                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
 885
 886         kfree(buf);
 887 }
 888
 889 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
 890 {
 891         struct virtnet_info *vi = netdev_priv(dev);
 892         struct scatterlist sg;
 893
 894         sg_init_one(&sg, &vid, sizeof(vid));
 895
 896         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
 897                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
 898                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
 899         return 0;
 900 }
 901
 902 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
 903 {
 904         struct virtnet_info *vi = netdev_priv(dev);
 905         struct scatterlist sg;
 906
 907         sg_init_one(&sg, &vid, sizeof(vid));
 908
 909         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
 910                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
 911                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
 912         return 0;
 913 }
 914
 915 static void virtnet_get_ringparam(struct net_device *dev,
 916                                 struct ethtool_ringparam *ring)
 917 {
 918         struct virtnet_info *vi = netdev_priv(dev);
 919
 920         ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq);
 921         ring->tx_max_pending = virtqueue_get_vring_size(vi->svq);
 922         ring->rx_pending = ring->rx_max_pending;
 923         ring->tx_pending = ring->tx_max_pending;
 924
 925 }
 926
 927
 928 static void virtnet_get_drvinfo(struct net_device *dev,
 929                                 struct ethtool_drvinfo *info)
 930 {
 931         struct virtnet_info *vi = netdev_priv(dev);
 932         struct virtio_device *vdev = vi->vdev;
 933
 934         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
 935         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
 936         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
 937
 938 }
 939
 940 static const struct ethtool_ops virtnet_ethtool_ops = {
 941         .get_drvinfo = virtnet_get_drvinfo,
 942         .get_link = ethtool_op_get_link,
 943         .get_ringparam = virtnet_get_ringparam,
 944 };
 945
 946 #define MIN_MTU 68
 947 #define MAX_MTU 65535
 948
 949 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
 950 {
 951         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
 952                 return -EINVAL;
 953         dev->mtu = new_mtu;
 954         return 0;
 955 }
 956
 957 static const struct net_device_ops virtnet_netdev = {
 958         .ndo_open            = virtnet_open,
 959         .ndo_stop            = virtnet_close,
 960         .ndo_start_xmit      = start_xmit,
 961         .ndo_validate_addr   = eth_validate_addr,
 962         .ndo_set_mac_address = virtnet_set_mac_address,
 963         .ndo_set_rx_mode     = virtnet_set_rx_mode,
 964         .ndo_change_mtu      = virtnet_change_mtu,
 965         .ndo_get_stats64     = virtnet_stats,
 966         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
 967         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
 968 #ifdef CONFIG_NET_POLL_CONTROLLER
 969         .ndo_poll_controller = virtnet_netpoll,
 970 #endif
 971 };
 972
 973 static void virtnet_config_changed_work(struct work_struct *work)
 974 {
 975         struct virtnet_info *vi =
 976                 container_of(work, struct virtnet_info, config_work);
 977         u16 v;
 978
 979         mutex_lock(&vi->config_lock);
 980         if (!vi->config_enable)
 981                 goto done;
 982
 983         if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
 984                               offsetof(struct virtio_net_config, status),
 985                               &v) < 0)
 986                 goto done;
 987
 988         if (v & VIRTIO_NET_S_ANNOUNCE) {
 989                 netif_notify_peers(vi->dev);
 990                 virtnet_ack_link_announce(vi);
 991         }
 992
 993         /* Ignore unknown (future) status bits */
 994         v &= VIRTIO_NET_S_LINK_UP;
 995
 996         if (vi->status == v)
 997                 goto done;
 998
 999         vi->status = v;
1000
1001         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1002                 netif_carrier_on(vi->dev);
1003                 netif_wake_queue(vi->dev);
1004         } else {
1005                 netif_carrier_off(vi->dev);
1006                 netif_stop_queue(vi->dev);
1007         }
1008 done:
1009         mutex_unlock(&vi->config_lock);
1010 }
1011
1012 static void virtnet_config_changed(struct virtio_device *vdev)
1013 {
1014         struct virtnet_info *vi = vdev->priv;
1015
1016         queue_work(system_nrt_wq, &vi->config_work);
1017 }
1018
1019 static int init_vqs(struct virtnet_info *vi)
1020 {
1021         struct virtqueue *vqs[3];
1022         vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
1023         const char *names[] = { "input", "output", "control" };
1024         int nvqs, err;
1025
1026         /* We expect two virtqueues, receive then send,
1027          * and optionally control. */
1028         nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
1029
1030         err = vi->vdev->config->find_vqs(vi->vdev, nvqs, vqs, callbacks, names);
1031         if (err)
1032                 return err;
1033
1034         vi->rvq = vqs[0];
1035         vi->svq = vqs[1];
1036
1037         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
1038                 vi->cvq = vqs[2];
1039
1040                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1041                         vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
1042         }
1043         return 0;
1044 }
1045
1046 static int virtnet_probe(struct virtio_device *vdev)
1047 {
1048         int err;
1049         struct net_device *dev;
1050         struct virtnet_info *vi;
1051
1052         /* Allocate ourselves a network device with room for our info */
1053         dev = alloc_etherdev(sizeof(struct virtnet_info));
1054         if (!dev)
1055                 return -ENOMEM;
1056
1057         /* Set up network device as normal. */
1058         dev->priv_flags |= IFF_UNICAST_FLT;
1059         dev->netdev_ops = &virtnet_netdev;
1060         dev->features = NETIF_F_HIGHDMA;
1061
1062         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1063         SET_NETDEV_DEV(dev, &vdev->dev);
1064
1065         /* Do we support "hardware" checksums? */
1066         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1067                 /* This opens up the world of extra features. */
1068                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1069                 if (csum)
1070                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1071
1072                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1073                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1074                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1075                 }
1076                 /* Individual feature bits: what can host handle? */
1077                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1078                         dev->hw_features |= NETIF_F_TSO;
1079                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1080                         dev->hw_features |= NETIF_F_TSO6;
1081                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1082                         dev->hw_features |= NETIF_F_TSO_ECN;
1083                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1084                         dev->hw_features |= NETIF_F_UFO;
1085
1086                 if (gso)
1087                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1088                 /* (!csum && gso) case will be fixed by register_netdev() */
1089         }
1090
1091         /* Configuration may specify what MAC to use.  Otherwise random. */
1092         if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
1093                                   offsetof(struct virtio_net_config, mac),
1094                                   dev->dev_addr, dev->addr_len) < 0)
1095                 eth_hw_addr_random(dev);
1096
1097         /* Set up our device-specific information */
1098         vi = netdev_priv(dev);
1099         netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
1100         vi->dev = dev;
1101         vi->vdev = vdev;
1102         vdev->priv = vi;
1103         vi->pages = NULL;
1104         vi->stats = alloc_percpu(struct virtnet_stats);
1105         err = -ENOMEM;
1106         if (vi->stats == NULL)
1107                 goto free;
1108
1109         INIT_DELAYED_WORK(&vi->refill, refill_work);
1110         mutex_init(&vi->config_lock);
1111         vi->config_enable = true;
1112         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1113         sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg));
1114         sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg));
1115
1116         /* If we can receive ANY GSO packets, we must allocate large ones. */
1117         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1118             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1119             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1120                 vi->big_packets = true;
1121
1122         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1123                 vi->mergeable_rx_bufs = true;
1124
1125         err = init_vqs(vi);
1126         if (err)
1127                 goto free_stats;
1128
1129         err = register_netdev(dev);
1130         if (err) {
1131                 pr_debug("virtio_net: registering device failed\n");
1132                 goto free_vqs;
1133         }
1134
1135         /* Last of all, set up some receive buffers. */
1136         try_fill_recv(vi, GFP_KERNEL);
1137
1138         /* If we didn't even get one input buffer, we're useless. */
1139         if (vi->num == 0) {
1140                 err = -ENOMEM;
1141                 goto unregister;
1142         }
1143
1144         /* Assume link up if device can't report link status,
1145            otherwise get link status from config. */
1146         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1147                 netif_carrier_off(dev);
1148                 queue_work(system_nrt_wq, &vi->config_work);
1149         } else {
1150                 vi->status = VIRTIO_NET_S_LINK_UP;
1151                 netif_carrier_on(dev);
1152         }
1153
1154         pr_debug("virtnet: registered device %s\n", dev->name);
1155         return 0;
1156
1157 unregister:
1158         unregister_netdev(dev);
1159 free_vqs:
1160         vdev->config->del_vqs(vdev);
1161 free_stats:
1162         free_percpu(vi->stats);
1163 free:
1164         free_netdev(dev);
1165         return err;
1166 }
1167
1168 static void free_unused_bufs(struct virtnet_info *vi)
1169 {
1170         void *buf;
1171         while (1) {
1172                 buf = virtqueue_detach_unused_buf(vi->svq);
1173                 if (!buf)
1174                         break;
1175                 dev_kfree_skb(buf);
1176         }
1177         while (1) {
1178                 buf = virtqueue_detach_unused_buf(vi->rvq);
1179                 if (!buf)
1180                         break;
1181                 if (vi->mergeable_rx_bufs || vi->big_packets)
1182                         give_pages(vi, buf);
1183                 else
1184                         dev_kfree_skb(buf);
1185                 --vi->num;
1186         }
1187         BUG_ON(vi->num != 0);
1188 }
1189
1190 static void remove_vq_common(struct virtnet_info *vi)
1191 {
1192         vi->vdev->config->reset(vi->vdev);
1193
1194         /* Free unused buffers in both send and recv, if any. */
1195         free_unused_bufs(vi);
1196
1197         vi->vdev->config->del_vqs(vi->vdev);
1198
1199         while (vi->pages)
1200                 __free_pages(get_a_page(vi, GFP_KERNEL), 0);
1201 }
1202
1203 static void __devexit virtnet_remove(struct virtio_device *vdev)
1204 {
1205         struct virtnet_info *vi = vdev->priv;
1206
1207         /* Prevent config work handler from accessing the device. */
1208         mutex_lock(&vi->config_lock);
1209         vi->config_enable = false;
1210         mutex_unlock(&vi->config_lock);
1211
1212         unregister_netdev(vi->dev);
1213
1214         remove_vq_common(vi);
1215
1216         flush_work(&vi->config_work);
1217
1218         free_percpu(vi->stats);
1219         free_netdev(vi->dev);
1220 }
1221
1222 #ifdef CONFIG_PM
1223 static int virtnet_freeze(struct virtio_device *vdev)
1224 {
1225         struct virtnet_info *vi = vdev->priv;
1226
1227         /* Prevent config work handler from accessing the device */
1228         mutex_lock(&vi->config_lock);
1229         vi->config_enable = false;
1230         mutex_unlock(&vi->config_lock);
1231
1232         virtqueue_disable_cb(vi->rvq);
1233         virtqueue_disable_cb(vi->svq);
1234         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ))
1235                 virtqueue_disable_cb(vi->cvq);
1236
1237         netif_device_detach(vi->dev);
1238         cancel_delayed_work_sync(&vi->refill);
1239
1240         if (netif_running(vi->dev))
1241                 napi_disable(&vi->napi);
1242
1243         remove_vq_common(vi);
1244
1245         flush_work(&vi->config_work);
1246
1247         return 0;
1248 }
1249
1250 static int virtnet_restore(struct virtio_device *vdev)
1251 {
1252         struct virtnet_info *vi = vdev->priv;
1253         int err;
1254
1255         err = init_vqs(vi);
1256         if (err)
1257                 return err;
1258
1259         if (netif_running(vi->dev))
1260                 virtnet_napi_enable(vi);
1261
1262         netif_device_attach(vi->dev);
1263
1264         if (!try_fill_recv(vi, GFP_KERNEL))
1265                 queue_delayed_work(system_nrt_wq, &vi->refill, 0);
1266
1267         mutex_lock(&vi->config_lock);
1268         vi->config_enable = true;
1269         mutex_unlock(&vi->config_lock);
1270
1271         return 0;
1272 }
1273 #endif
1274
1275 static struct virtio_device_id id_table[] = {
1276         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1277         { 0 },
1278 };
1279
1280 static unsigned int features[] = {
1281         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1282         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1283         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1284         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1285         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1286         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1287         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1288         VIRTIO_NET_F_GUEST_ANNOUNCE,
1289 };
1290
1291 static struct virtio_driver virtio_net_driver = {
1292         .feature_table = features,
1293         .feature_table_size = ARRAY_SIZE(features),
1294         .driver.name =  KBUILD_MODNAME,
1295         .driver.owner = THIS_MODULE,
1296         .id_table =     id_table,
1297         .probe =        virtnet_probe,
1298         .remove =       __devexit_p(virtnet_remove),
1299         .config_changed = virtnet_config_changed,
1300 #ifdef CONFIG_PM
1301         .freeze =       virtnet_freeze,
1302         .restore =      virtnet_restore,
1303 #endif
1304 };
1305
1306 static int __init init(void)
1307 {
1308         return register_virtio_driver(&virtio_net_driver);
1309 }
1310
1311 static void __exit fini(void)
1312 {
1313         unregister_virtio_driver(&virtio_net_driver);
1314 }
1315 module_init(init);
1316 module_exit(fini);
1317
1318 MODULE_DEVICE_TABLE(virtio, id_table);
1319 MODULE_DESCRIPTION("Virtio network driver");
1320 MODULE_LICENSE("GPL");