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, see <http://www.gnu.org/licenses/>.
  17  */
  18 //#define DEBUG
  19 #include <linux/netdevice.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/ethtool.h>
  22 #include <linux/module.h>
  23 #include <linux/virtio.h>
  24 #include <linux/virtio_net.h>
  25 #include <linux/scatterlist.h>
  26 #include <linux/if_vlan.h>
  27 #include <linux/slab.h>
  28 #include <linux/cpu.h>
  29 #include <linux/average.h>
  30
  31 static int napi_weight = NAPI_POLL_WEIGHT;
  32 module_param(napi_weight, int, 0444);
  33
  34 static bool csum = true, gso = true;
  35 module_param(csum, bool, 0444);
  36 module_param(gso, bool, 0444);
  37
  38 /* FIXME: MTU in config. */
  39 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  40 #define GOOD_COPY_LEN   128
  41
  42 /* Weight used for the RX packet size EWMA. The average packet size is used to
  43  * determine the packet buffer size when refilling RX rings. As the entire RX
  44  * ring may be refilled at once, the weight is chosen so that the EWMA will be
  45  * insensitive to short-term, transient changes in packet size.
  46  */
  47 #define RECEIVE_AVG_WEIGHT 64
  48
  49 /* Minimum alignment for mergeable packet buffers. */
  50 #define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
  51
  52 #define VIRTNET_DRIVER_VERSION "1.0.0"
  53
  54 struct virtnet_stats {
  55         struct u64_stats_sync tx_syncp;
  56         struct u64_stats_sync rx_syncp;
  57         u64 tx_bytes;
  58         u64 tx_packets;
  59
  60         u64 rx_bytes;
  61         u64 rx_packets;
  62 };
  63
  64 /* Internal representation of a send virtqueue */
  65 struct send_queue {
  66         /* Virtqueue associated with this send _queue */
  67         struct virtqueue *vq;
  68
  69         /* TX: fragments + linear part + virtio header */
  70         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  71
  72         /* Name of the send queue: output.$index */
  73         char name[40];
  74 };
  75
  76 /* Internal representation of a receive virtqueue */
  77 struct receive_queue {
  78         /* Virtqueue associated with this receive_queue */
  79         struct virtqueue *vq;
  80
  81         struct napi_struct napi;
  82
  83         /* Chain pages by the private ptr. */
  84         struct page *pages;
  85
  86         /* Average packet length for mergeable receive buffers. */
  87         struct ewma mrg_avg_pkt_len;
  88
  89         /* Page frag for packet buffer allocation. */
  90         struct page_frag alloc_frag;
  91
  92         /* RX: fragments + linear part + virtio header */
  93         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  94
  95         /* Name of this receive queue: input.$index */
  96         char name[40];
  97 };
  98
  99 struct virtnet_info {
 100         struct virtio_device *vdev;
 101         struct virtqueue *cvq;
 102         struct net_device *dev;
 103         struct send_queue *sq;
 104         struct receive_queue *rq;
 105         unsigned int status;
 106
 107         /* Max # of queue pairs supported by the device */
 108         u16 max_queue_pairs;
 109
 110         /* # of queue pairs currently used by the driver */
 111         u16 curr_queue_pairs;
 112
 113         /* I like... big packets and I cannot lie! */
 114         bool big_packets;
 115
 116         /* Host will merge rx buffers for big packets (shake it! shake it!) */
 117         bool mergeable_rx_bufs;
 118
 119         /* Has control virtqueue */
 120         bool has_cvq;
 121
 122         /* Host can handle any s/g split between our header and packet data */
 123         bool any_header_sg;
 124
 125         /* enable config space updates */
 126         bool config_enable;
 127
 128         /* Active statistics */
 129         struct virtnet_stats __percpu *stats;
 130
 131         /* Work struct for refilling if we run low on memory. */
 132         struct delayed_work refill;
 133
 134         /* Work struct for config space updates */
 135         struct work_struct config_work;
 136
 137         /* Lock for config space updates */
 138         struct mutex config_lock;
 139
 140         /* Does the affinity hint is set for virtqueues? */
 141         bool affinity_hint_set;
 142
 143         /* CPU hot plug notifier */
 144         struct notifier_block nb;
 145 };
 146
 147 struct skb_vnet_hdr {
 148         union {
 149                 struct virtio_net_hdr hdr;
 150                 struct virtio_net_hdr_mrg_rxbuf mhdr;
 151         };
 152 };
 153
 154 struct padded_vnet_hdr {
 155         struct virtio_net_hdr hdr;
 156         /*
 157          * virtio_net_hdr should be in a separated sg buffer because of a
 158          * QEMU bug, and data sg buffer shares same page with this header sg.
 159          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
 160          */
 161         char padding[6];
 162 };
 163
 164 /* Converting between virtqueue no. and kernel tx/rx queue no.
 165  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 166  */
 167 static int vq2txq(struct virtqueue *vq)
 168 {
 169         return (vq->index - 1) / 2;
 170 }
 171
 172 static int txq2vq(int txq)
 173 {
 174         return txq * 2 + 1;
 175 }
 176
 177 static int vq2rxq(struct virtqueue *vq)
 178 {
 179         return vq->index / 2;
 180 }
 181
 182 static int rxq2vq(int rxq)
 183 {
 184         return rxq * 2;
 185 }
 186
 187 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
 188 {
 189         return (struct skb_vnet_hdr *)skb->cb;
 190 }
 191
 192 /*
 193  * private is used to chain pages for big packets, put the whole
 194  * most recent used list in the beginning for reuse
 195  */
 196 static void give_pages(struct receive_queue *rq, struct page *page)
 197 {
 198         struct page *end;
 199
 200         /* Find end of list, sew whole thing into vi->rq.pages. */
 201         for (end = page; end->private; end = (struct page *)end->private);
 202         end->private = (unsigned long)rq->pages;
 203         rq->pages = page;
 204 }
 205
 206 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 207 {
 208         struct page *p = rq->pages;
 209
 210         if (p) {
 211                 rq->pages = (struct page *)p->private;
 212                 /* clear private here, it is used to chain pages */
 213                 p->private = 0;
 214         } else
 215                 p = alloc_page(gfp_mask);
 216         return p;
 217 }
 218
 219 static void skb_xmit_done(struct virtqueue *vq)
 220 {
 221         struct virtnet_info *vi = vq->vdev->priv;
 222
 223         /* Suppress further interrupts. */
 224         virtqueue_disable_cb(vq);
 225
 226         /* We were probably waiting for more output buffers. */
 227         netif_wake_subqueue(vi->dev, vq2txq(vq));
 228 }
 229
 230 static unsigned int mergeable_ctx_to_buf_truesize(unsigned long mrg_ctx)
 231 {
 232         unsigned int truesize = mrg_ctx & (MERGEABLE_BUFFER_ALIGN - 1);
 233         return (truesize + 1) * MERGEABLE_BUFFER_ALIGN;
 234 }
 235
 236 static void *mergeable_ctx_to_buf_address(unsigned long mrg_ctx)
 237 {
 238         return (void *)(mrg_ctx & -MERGEABLE_BUFFER_ALIGN);
 239
 240 }
 241
 242 static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize)
 243 {
 244         unsigned int size = truesize / MERGEABLE_BUFFER_ALIGN;
 245         return (unsigned long)buf | (size - 1);
 246 }
 247
 248 /* Called from bottom half context */
 249 static struct sk_buff *page_to_skb(struct receive_queue *rq,
 250                                    struct page *page, unsigned int offset,
 251                                    unsigned int len, unsigned int truesize)
 252 {
 253         struct virtnet_info *vi = rq->vq->vdev->priv;
 254         struct sk_buff *skb;
 255         struct skb_vnet_hdr *hdr;
 256         unsigned int copy, hdr_len, hdr_padded_len;
 257         char *p;
 258
 259         p = page_address(page) + offset;
 260
 261         /* copy small packet so we can reuse these pages for small data */
 262         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
 263         if (unlikely(!skb))
 264                 return NULL;
 265
 266         hdr = skb_vnet_hdr(skb);
 267
 268         if (vi->mergeable_rx_bufs) {
 269                 hdr_len = sizeof hdr->mhdr;
 270                 hdr_padded_len = sizeof hdr->mhdr;
 271         } else {
 272                 hdr_len = sizeof hdr->hdr;
 273                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 274         }
 275
 276         memcpy(hdr, p, hdr_len);
 277
 278         len -= hdr_len;
 279         offset += hdr_padded_len;
 280         p += hdr_padded_len;
 281
 282         copy = len;
 283         if (copy > skb_tailroom(skb))
 284                 copy = skb_tailroom(skb);
 285         memcpy(skb_put(skb, copy), p, copy);
 286
 287         len -= copy;
 288         offset += copy;
 289
 290         if (vi->mergeable_rx_bufs) {
 291                 if (len)
 292                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 293                 else
 294                         put_page(page);
 295                 return skb;
 296         }
 297
 298         /*
 299          * Verify that we can indeed put this data into a skb.
 300          * This is here to handle cases when the device erroneously
 301          * tries to receive more than is possible. This is usually
 302          * the case of a broken device.
 303          */
 304         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 305                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 306                 dev_kfree_skb(skb);
 307                 return NULL;
 308         }
 309         BUG_ON(offset >= PAGE_SIZE);
 310         while (len) {
 311                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 312                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 313                                 frag_size, truesize);
 314                 len -= frag_size;
 315                 page = (struct page *)page->private;
 316                 offset = 0;
 317         }
 318
 319         if (page)
 320                 give_pages(rq, page);
 321
 322         return skb;
 323 }
 324
 325 static struct sk_buff *receive_small(void *buf, unsigned int len)
 326 {
 327         struct sk_buff * skb = buf;
 328
 329         len -= sizeof(struct virtio_net_hdr);
 330         skb_trim(skb, len);
 331
 332         return skb;
 333 }
 334
 335 static struct sk_buff *receive_big(struct net_device *dev,
 336                                    struct receive_queue *rq,
 337                                    void *buf,
 338                                    unsigned int len)
 339 {
 340         struct page *page = buf;
 341         struct sk_buff *skb = page_to_skb(rq, page, 0, len, PAGE_SIZE);
 342
 343         if (unlikely(!skb))
 344                 goto err;
 345
 346         return skb;
 347
 348 err:
 349         dev->stats.rx_dropped++;
 350         give_pages(rq, page);
 351         return NULL;
 352 }
 353
 354 static struct sk_buff *receive_mergeable(struct net_device *dev,
 355                                          struct receive_queue *rq,
 356                                          unsigned long ctx,
 357                                          unsigned int len)
 358 {
 359         void *buf = mergeable_ctx_to_buf_address(ctx);
 360         struct skb_vnet_hdr *hdr = buf;
 361         int num_buf = hdr->mhdr.num_buffers;
 362         struct page *page = virt_to_head_page(buf);
 363         int offset = buf - page_address(page);
 364         unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 365
 366         struct sk_buff *head_skb = page_to_skb(rq, page, offset, len, truesize);
 367         struct sk_buff *curr_skb = head_skb;
 368
 369         if (unlikely(!curr_skb))
 370                 goto err_skb;
 371         while (--num_buf) {
 372                 int num_skb_frags;
 373
 374                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 375                 if (unlikely(!ctx)) {
 376                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
 377                                  dev->name, num_buf, hdr->mhdr.num_buffers);
 378                         dev->stats.rx_length_errors++;
 379                         goto err_buf;
 380                 }
 381
 382                 buf = mergeable_ctx_to_buf_address(ctx);
 383                 page = virt_to_head_page(buf);
 384
 385                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
 386                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
 387                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
 388
 389                         if (unlikely(!nskb))
 390                                 goto err_skb;
 391                         if (curr_skb == head_skb)
 392                                 skb_shinfo(curr_skb)->frag_list = nskb;
 393                         else
 394                                 curr_skb->next = nskb;
 395                         curr_skb = nskb;
 396                         head_skb->truesize += nskb->truesize;
 397                         num_skb_frags = 0;
 398                 }
 399                 truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 400                 if (curr_skb != head_skb) {
 401                         head_skb->data_len += len;
 402                         head_skb->len += len;
 403                         head_skb->truesize += truesize;
 404                 }
 405                 offset = buf - page_address(page);
 406                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
 407                         put_page(page);
 408                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
 409                                              len, truesize);
 410                 } else {
 411                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
 412                                         offset, len, truesize);
 413                 }
 414         }
 415
 416         ewma_add(&rq->mrg_avg_pkt_len, head_skb->len);
 417         return head_skb;
 418
 419 err_skb:
 420         put_page(page);
 421         while (--num_buf) {
 422                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 423                 if (unlikely(!ctx)) {
 424                         pr_debug("%s: rx error: %d buffers missing\n",
 425                                  dev->name, num_buf);
 426                         dev->stats.rx_length_errors++;
 427                         break;
 428                 }
 429                 page = virt_to_head_page(mergeable_ctx_to_buf_address(ctx));
 430                 put_page(page);
 431         }
 432 err_buf:
 433         dev->stats.rx_dropped++;
 434         dev_kfree_skb(head_skb);
 435         return NULL;
 436 }
 437
 438 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
 439 {
 440         struct virtnet_info *vi = rq->vq->vdev->priv;
 441         struct net_device *dev = vi->dev;
 442         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 443         struct sk_buff *skb;
 444         struct skb_vnet_hdr *hdr;
 445
 446         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
 447                 pr_debug("%s: short packet %i\n", dev->name, len);
 448                 dev->stats.rx_length_errors++;
 449                 if (vi->mergeable_rx_bufs) {
 450                         unsigned long ctx = (unsigned long)buf;
 451                         void *base = mergeable_ctx_to_buf_address(ctx);
 452                         put_page(virt_to_head_page(base));
 453                 } else if (vi->big_packets) {
 454                         give_pages(rq, buf);
 455                 } else {
 456                         dev_kfree_skb(buf);
 457                 }
 458                 return;
 459         }
 460
 461         if (vi->mergeable_rx_bufs)
 462                 skb = receive_mergeable(dev, rq, (unsigned long)buf, len);
 463         else if (vi->big_packets)
 464                 skb = receive_big(dev, rq, buf, len);
 465         else
 466                 skb = receive_small(buf, len);
 467
 468         if (unlikely(!skb))
 469                 return;
 470
 471         hdr = skb_vnet_hdr(skb);
 472
 473         u64_stats_update_begin(&stats->rx_syncp);
 474         stats->rx_bytes += skb->len;
 475         stats->rx_packets++;
 476         u64_stats_update_end(&stats->rx_syncp);
 477
 478         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 479                 pr_debug("Needs csum!\n");
 480                 if (!skb_partial_csum_set(skb,
 481                                           hdr->hdr.csum_start,
 482                                           hdr->hdr.csum_offset))
 483                         goto frame_err;
 484         } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
 485                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 486         }
 487
 488         skb->protocol = eth_type_trans(skb, dev);
 489         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 490                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 491
 492         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 493                 pr_debug("GSO!\n");
 494                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 495                 case VIRTIO_NET_HDR_GSO_TCPV4:
 496                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 497                         break;
 498                 case VIRTIO_NET_HDR_GSO_UDP:
 499                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 500                         break;
 501                 case VIRTIO_NET_HDR_GSO_TCPV6:
 502                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 503                         break;
 504                 default:
 505                         net_warn_ratelimited("%s: bad gso type %u.\n",
 506                                              dev->name, hdr->hdr.gso_type);
 507                         goto frame_err;
 508                 }
 509
 510                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 511                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 512
 513                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
 514                 if (skb_shinfo(skb)->gso_size == 0) {
 515                         net_warn_ratelimited("%s: zero gso size.\n", dev->name);
 516                         goto frame_err;
 517                 }
 518
 519                 /* Header must be checked, and gso_segs computed. */
 520                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 521                 skb_shinfo(skb)->gso_segs = 0;
 522         }
 523
 524         netif_receive_skb(skb);
 525         return;
 526
 527 frame_err:
 528         dev->stats.rx_frame_errors++;
 529         dev_kfree_skb(skb);
 530 }
 531
 532 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
 533 {
 534         struct virtnet_info *vi = rq->vq->vdev->priv;
 535         struct sk_buff *skb;
 536         struct skb_vnet_hdr *hdr;
 537         int err;
 538
 539         skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
 540         if (unlikely(!skb))
 541                 return -ENOMEM;
 542
 543         skb_put(skb, GOOD_PACKET_LEN);
 544
 545         hdr = skb_vnet_hdr(skb);
 546         sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
 547
 548         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 549
 550         err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
 551         if (err < 0)
 552                 dev_kfree_skb(skb);
 553
 554         return err;
 555 }
 556
 557 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
 558 {
 559         struct page *first, *list = NULL;
 560         char *p;
 561         int i, err, offset;
 562
 563         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 564         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 565                 first = get_a_page(rq, gfp);
 566                 if (!first) {
 567                         if (list)
 568                                 give_pages(rq, list);
 569                         return -ENOMEM;
 570                 }
 571                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
 572
 573                 /* chain new page in list head to match sg */
 574                 first->private = (unsigned long)list;
 575                 list = first;
 576         }
 577
 578         first = get_a_page(rq, gfp);
 579         if (!first) {
 580                 give_pages(rq, list);
 581                 return -ENOMEM;
 582         }
 583         p = page_address(first);
 584
 585         /* rq->sg[0], rq->sg[1] share the same page */
 586         /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
 587         sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
 588
 589         /* rq->sg[1] for data packet, from offset */
 590         offset = sizeof(struct padded_vnet_hdr);
 591         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
 592
 593         /* chain first in list head */
 594         first->private = (unsigned long)list;
 595         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
 596                                   first, gfp);
 597         if (err < 0)
 598                 give_pages(rq, first);
 599
 600         return err;
 601 }
 602
 603 static unsigned int get_mergeable_buf_len(struct ewma *avg_pkt_len)
 604 {
 605         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 606         unsigned int len;
 607
 608         len = hdr_len + clamp_t(unsigned int, ewma_read(avg_pkt_len),
 609                         GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
 610         return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
 611 }
 612
 613 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
 614 {
 615         struct page_frag *alloc_frag = &rq->alloc_frag;
 616         char *buf;
 617         unsigned long ctx;
 618         int err;
 619         unsigned int len, hole;
 620
 621         len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
 622         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
 623                 return -ENOMEM;
 624
 625         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
 626         ctx = mergeable_buf_to_ctx(buf, len);
 627         get_page(alloc_frag->page);
 628         alloc_frag->offset += len;
 629         hole = alloc_frag->size - alloc_frag->offset;
 630         if (hole < len) {
 631                 /* To avoid internal fragmentation, if there is very likely not
 632                  * enough space for another buffer, add the remaining space to
 633                  * the current buffer. This extra space is not included in
 634                  * the truesize stored in ctx.
 635                  */
 636                 len += hole;
 637                 alloc_frag->offset += hole;
 638         }
 639
 640         sg_init_one(rq->sg, buf, len);
 641         err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
 642         if (err < 0)
 643                 put_page(virt_to_head_page(buf));
 644
 645         return err;
 646 }
 647
 648 /*
 649  * Returns false if we couldn't fill entirely (OOM).
 650  *
 651  * Normally run in the receive path, but can also be run from ndo_open
 652  * before we're receiving packets, or from refill_work which is
 653  * careful to disable receiving (using napi_disable).
 654  */
 655 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
 656 {
 657         struct virtnet_info *vi = rq->vq->vdev->priv;
 658         int err;
 659         bool oom;
 660
 661         gfp |= __GFP_COLD;
 662         do {
 663                 if (vi->mergeable_rx_bufs)
 664                         err = add_recvbuf_mergeable(rq, gfp);
 665                 else if (vi->big_packets)
 666                         err = add_recvbuf_big(rq, gfp);
 667                 else
 668                         err = add_recvbuf_small(rq, gfp);
 669
 670                 oom = err == -ENOMEM;
 671                 if (err)
 672                         break;
 673         } while (rq->vq->num_free);
 674         virtqueue_kick(rq->vq);
 675         return !oom;
 676 }
 677
 678 static void skb_recv_done(struct virtqueue *rvq)
 679 {
 680         struct virtnet_info *vi = rvq->vdev->priv;
 681         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 682
 683         /* Schedule NAPI, Suppress further interrupts if successful. */
 684         if (napi_schedule_prep(&rq->napi)) {
 685                 virtqueue_disable_cb(rvq);
 686                 __napi_schedule(&rq->napi);
 687         }
 688 }
 689
 690 static void virtnet_napi_enable(struct receive_queue *rq)
 691 {
 692         napi_enable(&rq->napi);
 693
 694         /* If all buffers were filled by other side before we napi_enabled, we
 695          * won't get another interrupt, so process any outstanding packets
 696          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 697          * We synchronize against interrupts via NAPI_STATE_SCHED */
 698         if (napi_schedule_prep(&rq->napi)) {
 699                 virtqueue_disable_cb(rq->vq);
 700                 local_bh_disable();
 701                 __napi_schedule(&rq->napi);
 702                 local_bh_enable();
 703         }
 704 }
 705
 706 static void refill_work(struct work_struct *work)
 707 {
 708         struct virtnet_info *vi =
 709                 container_of(work, struct virtnet_info, refill.work);
 710         bool still_empty;
 711         int i;
 712
 713         for (i = 0; i < vi->curr_queue_pairs; i++) {
 714                 struct receive_queue *rq = &vi->rq[i];
 715
 716                 napi_disable(&rq->napi);
 717                 still_empty = !try_fill_recv(rq, GFP_KERNEL);
 718                 virtnet_napi_enable(rq);
 719
 720                 /* In theory, this can happen: if we don't get any buffers in
 721                  * we will *never* try to fill again.
 722                  */
 723                 if (still_empty)
 724                         schedule_delayed_work(&vi->refill, HZ/2);
 725         }
 726 }
 727
 728 static int virtnet_poll(struct napi_struct *napi, int budget)
 729 {
 730         struct receive_queue *rq =
 731                 container_of(napi, struct receive_queue, napi);
 732         struct virtnet_info *vi = rq->vq->vdev->priv;
 733         void *buf;
 734         unsigned int r, len, received = 0;
 735
 736 again:
 737         while (received < budget &&
 738                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
 739                 receive_buf(rq, buf, len);
 740                 received++;
 741         }
 742
 743         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
 744                 if (!try_fill_recv(rq, GFP_ATOMIC))
 745                         schedule_delayed_work(&vi->refill, 0);
 746         }
 747
 748         /* Out of packets? */
 749         if (received < budget) {
 750                 r = virtqueue_enable_cb_prepare(rq->vq);
 751                 napi_complete(napi);
 752                 if (unlikely(virtqueue_poll(rq->vq, r)) &&
 753                     napi_schedule_prep(napi)) {
 754                         virtqueue_disable_cb(rq->vq);
 755                         __napi_schedule(napi);
 756                         goto again;
 757                 }
 758         }
 759
 760         return received;
 761 }
 762
 763 static int virtnet_open(struct net_device *dev)
 764 {
 765         struct virtnet_info *vi = netdev_priv(dev);
 766         int i;
 767
 768         for (i = 0; i < vi->max_queue_pairs; i++) {
 769                 if (i < vi->curr_queue_pairs)
 770                         /* Make sure we have some buffers: if oom use wq. */
 771                         if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
 772                                 schedule_delayed_work(&vi->refill, 0);
 773                 virtnet_napi_enable(&vi->rq[i]);
 774         }
 775
 776         return 0;
 777 }
 778
 779 static void free_old_xmit_skbs(struct send_queue *sq)
 780 {
 781         struct sk_buff *skb;
 782         unsigned int len;
 783         struct virtnet_info *vi = sq->vq->vdev->priv;
 784         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 785
 786         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 787                 pr_debug("Sent skb %p\n", skb);
 788
 789                 u64_stats_update_begin(&stats->tx_syncp);
 790                 stats->tx_bytes += skb->len;
 791                 stats->tx_packets++;
 792                 u64_stats_update_end(&stats->tx_syncp);
 793
 794                 dev_kfree_skb_any(skb);
 795         }
 796 }
 797
 798 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 799 {
 800         struct skb_vnet_hdr *hdr;
 801         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 802         struct virtnet_info *vi = sq->vq->vdev->priv;
 803         unsigned num_sg;
 804         unsigned hdr_len;
 805         bool can_push;
 806
 807         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 808         if (vi->mergeable_rx_bufs)
 809                 hdr_len = sizeof hdr->mhdr;
 810         else
 811                 hdr_len = sizeof hdr->hdr;
 812
 813         can_push = vi->any_header_sg &&
 814                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
 815                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
 816         /* Even if we can, don't push here yet as this would skew
 817          * csum_start offset below. */
 818         if (can_push)
 819                 hdr = (struct skb_vnet_hdr *)(skb->data - hdr_len);
 820         else
 821                 hdr = skb_vnet_hdr(skb);
 822
 823         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 824                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 825                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
 826                 hdr->hdr.csum_offset = skb->csum_offset;
 827         } else {
 828                 hdr->hdr.flags = 0;
 829                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 830         }
 831
 832         if (skb_is_gso(skb)) {
 833                 hdr->hdr.hdr_len = skb_headlen(skb);
 834                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
 835                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 836                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 837                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 838                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 839                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 840                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 841                 else
 842                         BUG();
 843                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 844                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 845         } else {
 846                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 847                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
 848         }
 849
 850         if (vi->mergeable_rx_bufs)
 851                 hdr->mhdr.num_buffers = 0;
 852
 853         if (can_push) {
 854                 __skb_push(skb, hdr_len);
 855                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
 856                 /* Pull header back to avoid skew in tx bytes calculations. */
 857                 __skb_pull(skb, hdr_len);
 858         } else {
 859                 sg_set_buf(sq->sg, hdr, hdr_len);
 860                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
 861         }
 862         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
 863 }
 864
 865 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 866 {
 867         struct virtnet_info *vi = netdev_priv(dev);
 868         int qnum = skb_get_queue_mapping(skb);
 869         struct send_queue *sq = &vi->sq[qnum];
 870         int err;
 871
 872         /* Free up any pending old buffers before queueing new ones. */
 873         free_old_xmit_skbs(sq);
 874
 875         /* Try to transmit */
 876         err = xmit_skb(sq, skb);
 877
 878         /* This should not happen! */
 879         if (unlikely(err)) {
 880                 dev->stats.tx_fifo_errors++;
 881                 if (net_ratelimit())
 882                         dev_warn(&dev->dev,
 883                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
 884                 dev->stats.tx_dropped++;
 885                 dev_kfree_skb_any(skb);
 886                 return NETDEV_TX_OK;
 887         }
 888         virtqueue_kick(sq->vq);
 889
 890         /* Don't wait up for transmitted skbs to be freed. */
 891         skb_orphan(skb);
 892         nf_reset(skb);
 893
 894         /* Apparently nice girls don't return TX_BUSY; stop the queue
 895          * before it gets out of hand.  Naturally, this wastes entries. */
 896         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
 897                 netif_stop_subqueue(dev, qnum);
 898                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 899                         /* More just got used, free them then recheck. */
 900                         free_old_xmit_skbs(sq);
 901                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
 902                                 netif_start_subqueue(dev, qnum);
 903                                 virtqueue_disable_cb(sq->vq);
 904                         }
 905                 }
 906         }
 907
 908         return NETDEV_TX_OK;
 909 }
 910
 911 /*
 912  * Send command via the control virtqueue and check status.  Commands
 913  * supported by the hypervisor, as indicated by feature bits, should
 914  * never fail unless improperly formatted.
 915  */
 916 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 917                                  struct scatterlist *out)
 918 {
 919         struct scatterlist *sgs[4], hdr, stat;
 920         struct virtio_net_ctrl_hdr ctrl;
 921         virtio_net_ctrl_ack status = ~0;
 922         unsigned out_num = 0, tmp;
 923
 924         /* Caller should know better */
 925         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
 926
 927         ctrl.class = class;
 928         ctrl.cmd = cmd;
 929         /* Add header */
 930         sg_init_one(&hdr, &ctrl, sizeof(ctrl));
 931         sgs[out_num++] = &hdr;
 932
 933         if (out)
 934                 sgs[out_num++] = out;
 935
 936         /* Add return status. */
 937         sg_init_one(&stat, &status, sizeof(status));
 938         sgs[out_num] = &stat;
 939
 940         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
 941         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
 942
 943         if (unlikely(!virtqueue_kick(vi->cvq)))
 944                 return status == VIRTIO_NET_OK;
 945
 946         /* Spin for a response, the kick causes an ioport write, trapping
 947          * into the hypervisor, so the request should be handled immediately.
 948          */
 949         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
 950                !virtqueue_is_broken(vi->cvq))
 951                 cpu_relax();
 952
 953         return status == VIRTIO_NET_OK;
 954 }
 955
 956 static int virtnet_set_mac_address(struct net_device *dev, void *p)
 957 {
 958         struct virtnet_info *vi = netdev_priv(dev);
 959         struct virtio_device *vdev = vi->vdev;
 960         int ret;
 961         struct sockaddr *addr = p;
 962         struct scatterlist sg;
 963
 964         ret = eth_prepare_mac_addr_change(dev, p);
 965         if (ret)
 966                 return ret;
 967
 968         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
 969                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
 970                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
 971                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
 972                         dev_warn(&vdev->dev,
 973                                  "Failed to set mac address by vq command.\n");
 974                         return -EINVAL;
 975                 }
 976         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
 977                 unsigned int i;
 978
 979                 /* Naturally, this has an atomicity problem. */
 980                 for (i = 0; i < dev->addr_len; i++)
 981                         virtio_cwrite8(vdev,
 982                                        offsetof(struct virtio_net_config, mac) +
 983                                        i, addr->sa_data[i]);
 984         }
 985
 986         eth_commit_mac_addr_change(dev, p);
 987
 988         return 0;
 989 }
 990
 991 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
 992                                                struct rtnl_link_stats64 *tot)
 993 {
 994         struct virtnet_info *vi = netdev_priv(dev);
 995         int cpu;
 996         unsigned int start;
 997
 998         for_each_possible_cpu(cpu) {
 999                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1000                 u64 tpackets, tbytes, rpackets, rbytes;
1001
1002                 do {
1003                         start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
1004                         tpackets = stats->tx_packets;
1005                         tbytes   = stats->tx_bytes;
1006                 } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
1007
1008                 do {
1009                         start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
1010                         rpackets = stats->rx_packets;
1011                         rbytes   = stats->rx_bytes;
1012                 } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
1013
1014                 tot->rx_packets += rpackets;
1015                 tot->tx_packets += tpackets;
1016                 tot->rx_bytes   += rbytes;
1017                 tot->tx_bytes   += tbytes;
1018         }
1019
1020         tot->tx_dropped = dev->stats.tx_dropped;
1021         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1022         tot->rx_dropped = dev->stats.rx_dropped;
1023         tot->rx_length_errors = dev->stats.rx_length_errors;
1024         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1025
1026         return tot;
1027 }
1028
1029 #ifdef CONFIG_NET_POLL_CONTROLLER
1030 static void virtnet_netpoll(struct net_device *dev)
1031 {
1032         struct virtnet_info *vi = netdev_priv(dev);
1033         int i;
1034
1035         for (i = 0; i < vi->curr_queue_pairs; i++)
1036                 napi_schedule(&vi->rq[i].napi);
1037 }
1038 #endif
1039
1040 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1041 {
1042         rtnl_lock();
1043         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1044                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1045                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1046         rtnl_unlock();
1047 }
1048
1049 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1050 {
1051         struct scatterlist sg;
1052         struct virtio_net_ctrl_mq s;
1053         struct net_device *dev = vi->dev;
1054
1055         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1056                 return 0;
1057
1058         s.virtqueue_pairs = queue_pairs;
1059         sg_init_one(&sg, &s, sizeof(s));
1060
1061         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1062                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1063                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1064                          queue_pairs);
1065                 return -EINVAL;
1066         } else {
1067                 vi->curr_queue_pairs = queue_pairs;
1068                 /* virtnet_open() will refill when device is going to up. */
1069                 if (dev->flags & IFF_UP)
1070                         schedule_delayed_work(&vi->refill, 0);
1071         }
1072
1073         return 0;
1074 }
1075
1076 static int virtnet_close(struct net_device *dev)
1077 {
1078         struct virtnet_info *vi = netdev_priv(dev);
1079         int i;
1080
1081         /* Make sure refill_work doesn't re-enable napi! */
1082         cancel_delayed_work_sync(&vi->refill);
1083
1084         for (i = 0; i < vi->max_queue_pairs; i++)
1085                 napi_disable(&vi->rq[i].napi);
1086
1087         return 0;
1088 }
1089
1090 static void virtnet_set_rx_mode(struct net_device *dev)
1091 {
1092         struct virtnet_info *vi = netdev_priv(dev);
1093         struct scatterlist sg[2];
1094         u8 promisc, allmulti;
1095         struct virtio_net_ctrl_mac *mac_data;
1096         struct netdev_hw_addr *ha;
1097         int uc_count;
1098         int mc_count;
1099         void *buf;
1100         int i;
1101
1102         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1103         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1104                 return;
1105
1106         promisc = ((dev->flags & IFF_PROMISC) != 0);
1107         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1108
1109         sg_init_one(sg, &promisc, sizeof(promisc));
1110
1111         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1112                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1113                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1114                          promisc ? "en" : "dis");
1115
1116         sg_init_one(sg, &allmulti, sizeof(allmulti));
1117
1118         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1119                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1120                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1121                          allmulti ? "en" : "dis");
1122
1123         uc_count = netdev_uc_count(dev);
1124         mc_count = netdev_mc_count(dev);
1125         /* MAC filter - use one buffer for both lists */
1126         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1127                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1128         mac_data = buf;
1129         if (!buf)
1130                 return;
1131
1132         sg_init_table(sg, 2);
1133
1134         /* Store the unicast list and count in the front of the buffer */
1135         mac_data->entries = uc_count;
1136         i = 0;
1137         netdev_for_each_uc_addr(ha, dev)
1138                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1139
1140         sg_set_buf(&sg[0], mac_data,
1141                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1142
1143         /* multicast list and count fill the end */
1144         mac_data = (void *)&mac_data->macs[uc_count][0];
1145
1146         mac_data->entries = mc_count;
1147         i = 0;
1148         netdev_for_each_mc_addr(ha, dev)
1149                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1150
1151         sg_set_buf(&sg[1], mac_data,
1152                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1153
1154         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1155                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1156                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1157
1158         kfree(buf);
1159 }
1160
1161 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1162                                    __be16 proto, u16 vid)
1163 {
1164         struct virtnet_info *vi = netdev_priv(dev);
1165         struct scatterlist sg;
1166
1167         sg_init_one(&sg, &vid, sizeof(vid));
1168
1169         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1170                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1171                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1172         return 0;
1173 }
1174
1175 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1176                                     __be16 proto, u16 vid)
1177 {
1178         struct virtnet_info *vi = netdev_priv(dev);
1179         struct scatterlist sg;
1180
1181         sg_init_one(&sg, &vid, sizeof(vid));
1182
1183         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1184                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1185                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1186         return 0;
1187 }
1188
1189 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1190 {
1191         int i;
1192
1193         if (vi->affinity_hint_set) {
1194                 for (i = 0; i < vi->max_queue_pairs; i++) {
1195                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1196                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1197                 }
1198
1199                 vi->affinity_hint_set = false;
1200         }
1201 }
1202
1203 static void virtnet_set_affinity(struct virtnet_info *vi)
1204 {
1205         int i;
1206         int cpu;
1207
1208         /* In multiqueue mode, when the number of cpu is equal to the number of
1209          * queue pairs, we let the queue pairs to be private to one cpu by
1210          * setting the affinity hint to eliminate the contention.
1211          */
1212         if (vi->curr_queue_pairs == 1 ||
1213             vi->max_queue_pairs != num_online_cpus()) {
1214                 virtnet_clean_affinity(vi, -1);
1215                 return;
1216         }
1217
1218         i = 0;
1219         for_each_online_cpu(cpu) {
1220                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1221                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1222                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1223                 i++;
1224         }
1225
1226         vi->affinity_hint_set = true;
1227 }
1228
1229 static int virtnet_cpu_callback(struct notifier_block *nfb,
1230                                 unsigned long action, void *hcpu)
1231 {
1232         struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);
1233
1234         switch(action & ~CPU_TASKS_FROZEN) {
1235         case CPU_ONLINE:
1236         case CPU_DOWN_FAILED:
1237         case CPU_DEAD:
1238                 virtnet_set_affinity(vi);
1239                 break;
1240         case CPU_DOWN_PREPARE:
1241                 virtnet_clean_affinity(vi, (long)hcpu);
1242                 break;
1243         default:
1244                 break;
1245         }
1246
1247         return NOTIFY_OK;
1248 }
1249
1250 static void virtnet_get_ringparam(struct net_device *dev,
1251                                 struct ethtool_ringparam *ring)
1252 {
1253         struct virtnet_info *vi = netdev_priv(dev);
1254
1255         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1256         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1257         ring->rx_pending = ring->rx_max_pending;
1258         ring->tx_pending = ring->tx_max_pending;
1259 }
1260
1261
1262 static void virtnet_get_drvinfo(struct net_device *dev,
1263                                 struct ethtool_drvinfo *info)
1264 {
1265         struct virtnet_info *vi = netdev_priv(dev);
1266         struct virtio_device *vdev = vi->vdev;
1267
1268         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1269         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1270         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1271
1272 }
1273
1274 /* TODO: Eliminate OOO packets during switching */
1275 static int virtnet_set_channels(struct net_device *dev,
1276                                 struct ethtool_channels *channels)
1277 {
1278         struct virtnet_info *vi = netdev_priv(dev);
1279         u16 queue_pairs = channels->combined_count;
1280         int err;
1281
1282         /* We don't support separate rx/tx channels.
1283          * We don't allow setting 'other' channels.
1284          */
1285         if (channels->rx_count || channels->tx_count || channels->other_count)
1286                 return -EINVAL;
1287
1288         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1289                 return -EINVAL;
1290
1291         get_online_cpus();
1292         err = virtnet_set_queues(vi, queue_pairs);
1293         if (!err) {
1294                 netif_set_real_num_tx_queues(dev, queue_pairs);
1295                 netif_set_real_num_rx_queues(dev, queue_pairs);
1296
1297                 virtnet_set_affinity(vi);
1298         }
1299         put_online_cpus();
1300
1301         return err;
1302 }
1303
1304 static void virtnet_get_channels(struct net_device *dev,
1305                                  struct ethtool_channels *channels)
1306 {
1307         struct virtnet_info *vi = netdev_priv(dev);
1308
1309         channels->combined_count = vi->curr_queue_pairs;
1310         channels->max_combined = vi->max_queue_pairs;
1311         channels->max_other = 0;
1312         channels->rx_count = 0;
1313         channels->tx_count = 0;
1314         channels->other_count = 0;
1315 }
1316
1317 static const struct ethtool_ops virtnet_ethtool_ops = {
1318         .get_drvinfo = virtnet_get_drvinfo,
1319         .get_link = ethtool_op_get_link,
1320         .get_ringparam = virtnet_get_ringparam,
1321         .set_channels = virtnet_set_channels,
1322         .get_channels = virtnet_get_channels,
1323 };
1324
1325 #define MIN_MTU 68
1326 #define MAX_MTU 65535
1327
1328 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1329 {
1330         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1331                 return -EINVAL;
1332         dev->mtu = new_mtu;
1333         return 0;
1334 }
1335
1336 static const struct net_device_ops virtnet_netdev = {
1337         .ndo_open            = virtnet_open,
1338         .ndo_stop            = virtnet_close,
1339         .ndo_start_xmit      = start_xmit,
1340         .ndo_validate_addr   = eth_validate_addr,
1341         .ndo_set_mac_address = virtnet_set_mac_address,
1342         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1343         .ndo_change_mtu      = virtnet_change_mtu,
1344         .ndo_get_stats64     = virtnet_stats,
1345         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1346         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1347 #ifdef CONFIG_NET_POLL_CONTROLLER
1348         .ndo_poll_controller = virtnet_netpoll,
1349 #endif
1350 };
1351
1352 static void virtnet_config_changed_work(struct work_struct *work)
1353 {
1354         struct virtnet_info *vi =
1355                 container_of(work, struct virtnet_info, config_work);
1356         u16 v;
1357
1358         mutex_lock(&vi->config_lock);
1359         if (!vi->config_enable)
1360                 goto done;
1361
1362         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
1363                                  struct virtio_net_config, status, &v) < 0)
1364                 goto done;
1365
1366         if (v & VIRTIO_NET_S_ANNOUNCE) {
1367                 netdev_notify_peers(vi->dev);
1368                 virtnet_ack_link_announce(vi);
1369         }
1370
1371         /* Ignore unknown (future) status bits */
1372         v &= VIRTIO_NET_S_LINK_UP;
1373
1374         if (vi->status == v)
1375                 goto done;
1376
1377         vi->status = v;
1378
1379         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1380                 netif_carrier_on(vi->dev);
1381                 netif_tx_wake_all_queues(vi->dev);
1382         } else {
1383                 netif_carrier_off(vi->dev);
1384                 netif_tx_stop_all_queues(vi->dev);
1385         }
1386 done:
1387         mutex_unlock(&vi->config_lock);
1388 }
1389
1390 static void virtnet_config_changed(struct virtio_device *vdev)
1391 {
1392         struct virtnet_info *vi = vdev->priv;
1393
1394         schedule_work(&vi->config_work);
1395 }
1396
1397 static void virtnet_free_queues(struct virtnet_info *vi)
1398 {
1399         int i;
1400
1401         for (i = 0; i < vi->max_queue_pairs; i++)
1402                 netif_napi_del(&vi->rq[i].napi);
1403
1404         kfree(vi->rq);
1405         kfree(vi->sq);
1406 }
1407
1408 static void free_receive_bufs(struct virtnet_info *vi)
1409 {
1410         int i;
1411
1412         for (i = 0; i < vi->max_queue_pairs; i++) {
1413                 while (vi->rq[i].pages)
1414                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1415         }
1416 }
1417
1418 static void free_receive_page_frags(struct virtnet_info *vi)
1419 {
1420         int i;
1421         for (i = 0; i < vi->max_queue_pairs; i++)
1422                 if (vi->rq[i].alloc_frag.page)
1423                         put_page(vi->rq[i].alloc_frag.page);
1424 }
1425
1426 static void free_unused_bufs(struct virtnet_info *vi)
1427 {
1428         void *buf;
1429         int i;
1430
1431         for (i = 0; i < vi->max_queue_pairs; i++) {
1432                 struct virtqueue *vq = vi->sq[i].vq;
1433                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1434                         dev_kfree_skb(buf);
1435         }
1436
1437         for (i = 0; i < vi->max_queue_pairs; i++) {
1438                 struct virtqueue *vq = vi->rq[i].vq;
1439
1440                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1441                         if (vi->mergeable_rx_bufs) {
1442                                 unsigned long ctx = (unsigned long)buf;
1443                                 void *base = mergeable_ctx_to_buf_address(ctx);
1444                                 put_page(virt_to_head_page(base));
1445                         } else if (vi->big_packets) {
1446                                 give_pages(&vi->rq[i], buf);
1447                         } else {
1448                                 dev_kfree_skb(buf);
1449                         }
1450                 }
1451         }
1452 }
1453
1454 static void virtnet_del_vqs(struct virtnet_info *vi)
1455 {
1456         struct virtio_device *vdev = vi->vdev;
1457
1458         virtnet_clean_affinity(vi, -1);
1459
1460         vdev->config->del_vqs(vdev);
1461
1462         virtnet_free_queues(vi);
1463 }
1464
1465 static int virtnet_find_vqs(struct virtnet_info *vi)
1466 {
1467         vq_callback_t **callbacks;
1468         struct virtqueue **vqs;
1469         int ret = -ENOMEM;
1470         int i, total_vqs;
1471         const char **names;
1472
1473         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1474          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1475          * possible control vq.
1476          */
1477         total_vqs = vi->max_queue_pairs * 2 +
1478                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1479
1480         /* Allocate space for find_vqs parameters */
1481         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1482         if (!vqs)
1483                 goto err_vq;
1484         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1485         if (!callbacks)
1486                 goto err_callback;
1487         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1488         if (!names)
1489                 goto err_names;
1490
1491         /* Parameters for control virtqueue, if any */
1492         if (vi->has_cvq) {
1493                 callbacks[total_vqs - 1] = NULL;
1494                 names[total_vqs - 1] = "control";
1495         }
1496
1497         /* Allocate/initialize parameters for send/receive virtqueues */
1498         for (i = 0; i < vi->max_queue_pairs; i++) {
1499                 callbacks[rxq2vq(i)] = skb_recv_done;
1500                 callbacks[txq2vq(i)] = skb_xmit_done;
1501                 sprintf(vi->rq[i].name, "input.%d", i);
1502                 sprintf(vi->sq[i].name, "output.%d", i);
1503                 names[rxq2vq(i)] = vi->rq[i].name;
1504                 names[txq2vq(i)] = vi->sq[i].name;
1505         }
1506
1507         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1508                                          names);
1509         if (ret)
1510                 goto err_find;
1511
1512         if (vi->has_cvq) {
1513                 vi->cvq = vqs[total_vqs - 1];
1514                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1515                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1516         }
1517
1518         for (i = 0; i < vi->max_queue_pairs; i++) {
1519                 vi->rq[i].vq = vqs[rxq2vq(i)];
1520                 vi->sq[i].vq = vqs[txq2vq(i)];
1521         }
1522
1523         kfree(names);
1524         kfree(callbacks);
1525         kfree(vqs);
1526
1527         return 0;
1528
1529 err_find:
1530         kfree(names);
1531 err_names:
1532         kfree(callbacks);
1533 err_callback:
1534         kfree(vqs);
1535 err_vq:
1536         return ret;
1537 }
1538
1539 static int virtnet_alloc_queues(struct virtnet_info *vi)
1540 {
1541         int i;
1542
1543         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1544         if (!vi->sq)
1545                 goto err_sq;
1546         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1547         if (!vi->rq)
1548                 goto err_rq;
1549
1550         INIT_DELAYED_WORK(&vi->refill, refill_work);
1551         for (i = 0; i < vi->max_queue_pairs; i++) {
1552                 vi->rq[i].pages = NULL;
1553                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1554                                napi_weight);
1555
1556                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1557                 ewma_init(&vi->rq[i].mrg_avg_pkt_len, 1, RECEIVE_AVG_WEIGHT);
1558                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1559         }
1560
1561         return 0;
1562
1563 err_rq:
1564         kfree(vi->sq);
1565 err_sq:
1566         return -ENOMEM;
1567 }
1568
1569 static int init_vqs(struct virtnet_info *vi)
1570 {
1571         int ret;
1572
1573         /* Allocate send & receive queues */
1574         ret = virtnet_alloc_queues(vi);
1575         if (ret)
1576                 goto err;
1577
1578         ret = virtnet_find_vqs(vi);
1579         if (ret)
1580                 goto err_free;
1581
1582         get_online_cpus();
1583         virtnet_set_affinity(vi);
1584         put_online_cpus();
1585
1586         return 0;
1587
1588 err_free:
1589         virtnet_free_queues(vi);
1590 err:
1591         return ret;
1592 }
1593
1594 #ifdef CONFIG_SYSFS
1595 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
1596                 struct rx_queue_attribute *attribute, char *buf)
1597 {
1598         struct virtnet_info *vi = netdev_priv(queue->dev);
1599         unsigned int queue_index = get_netdev_rx_queue_index(queue);
1600         struct ewma *avg;
1601
1602         BUG_ON(queue_index >= vi->max_queue_pairs);
1603         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
1604         return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
1605 }
1606
1607 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
1608         __ATTR_RO(mergeable_rx_buffer_size);
1609
1610 static struct attribute *virtio_net_mrg_rx_attrs[] = {
1611         &mergeable_rx_buffer_size_attribute.attr,
1612         NULL
1613 };
1614
1615 static const struct attribute_group virtio_net_mrg_rx_group = {
1616         .name = "virtio_net",
1617         .attrs = virtio_net_mrg_rx_attrs
1618 };
1619 #endif
1620
1621 static int virtnet_probe(struct virtio_device *vdev)
1622 {
1623         int i, err;
1624         struct net_device *dev;
1625         struct virtnet_info *vi;
1626         u16 max_queue_pairs;
1627
1628         /* Find if host supports multiqueue virtio_net device */
1629         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
1630                                    struct virtio_net_config,
1631                                    max_virtqueue_pairs, &max_queue_pairs);
1632
1633         /* We need at least 2 queue's */
1634         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1635             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1636             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1637                 max_queue_pairs = 1;
1638
1639         /* Allocate ourselves a network device with room for our info */
1640         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1641         if (!dev)
1642                 return -ENOMEM;
1643
1644         /* Set up network device as normal. */
1645         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1646         dev->netdev_ops = &virtnet_netdev;
1647         dev->features = NETIF_F_HIGHDMA;
1648
1649         dev->ethtool_ops = &virtnet_ethtool_ops;
1650         SET_NETDEV_DEV(dev, &vdev->dev);
1651
1652         /* Do we support "hardware" checksums? */
1653         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1654                 /* This opens up the world of extra features. */
1655                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1656                 if (csum)
1657                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1658
1659                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1660                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1661                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1662                 }
1663                 /* Individual feature bits: what can host handle? */
1664                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1665                         dev->hw_features |= NETIF_F_TSO;
1666                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1667                         dev->hw_features |= NETIF_F_TSO6;
1668                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1669                         dev->hw_features |= NETIF_F_TSO_ECN;
1670                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1671                         dev->hw_features |= NETIF_F_UFO;
1672
1673                 if (gso)
1674                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1675                 /* (!csum && gso) case will be fixed by register_netdev() */
1676         }
1677         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
1678                 dev->features |= NETIF_F_RXCSUM;
1679
1680         dev->vlan_features = dev->features;
1681
1682         /* Configuration may specify what MAC to use.  Otherwise random. */
1683         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
1684                 virtio_cread_bytes(vdev,
1685                                    offsetof(struct virtio_net_config, mac),
1686                                    dev->dev_addr, dev->addr_len);
1687         else
1688                 eth_hw_addr_random(dev);
1689
1690         /* Set up our device-specific information */
1691         vi = netdev_priv(dev);
1692         vi->dev = dev;
1693         vi->vdev = vdev;
1694         vdev->priv = vi;
1695         vi->stats = alloc_percpu(struct virtnet_stats);
1696         err = -ENOMEM;
1697         if (vi->stats == NULL)
1698                 goto free;
1699
1700         for_each_possible_cpu(i) {
1701                 struct virtnet_stats *virtnet_stats;
1702                 virtnet_stats = per_cpu_ptr(vi->stats, i);
1703                 u64_stats_init(&virtnet_stats->tx_syncp);
1704                 u64_stats_init(&virtnet_stats->rx_syncp);
1705         }
1706
1707         mutex_init(&vi->config_lock);
1708         vi->config_enable = true;
1709         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1710
1711         /* If we can receive ANY GSO packets, we must allocate large ones. */
1712         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1713             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1714             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
1715             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
1716                 vi->big_packets = true;
1717
1718         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1719                 vi->mergeable_rx_bufs = true;
1720
1721         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT))
1722                 vi->any_header_sg = true;
1723
1724         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1725                 vi->has_cvq = true;
1726
1727         if (vi->any_header_sg) {
1728                 if (vi->mergeable_rx_bufs)
1729                         dev->needed_headroom = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1730                 else
1731                         dev->needed_headroom = sizeof(struct virtio_net_hdr);
1732         }
1733
1734         /* Use single tx/rx queue pair as default */
1735         vi->curr_queue_pairs = 1;
1736         vi->max_queue_pairs = max_queue_pairs;
1737
1738         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1739         err = init_vqs(vi);
1740         if (err)
1741                 goto free_stats;
1742
1743 #ifdef CONFIG_SYSFS
1744         if (vi->mergeable_rx_bufs)
1745                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
1746 #endif
1747         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
1748         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
1749
1750         err = register_netdev(dev);
1751         if (err) {
1752                 pr_debug("virtio_net: registering device failed\n");
1753                 goto free_vqs;
1754         }
1755
1756         /* Last of all, set up some receive buffers. */
1757         for (i = 0; i < vi->curr_queue_pairs; i++) {
1758                 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1759
1760                 /* If we didn't even get one input buffer, we're useless. */
1761                 if (vi->rq[i].vq->num_free ==
1762                     virtqueue_get_vring_size(vi->rq[i].vq)) {
1763                         free_unused_bufs(vi);
1764                         err = -ENOMEM;
1765                         goto free_recv_bufs;
1766                 }
1767         }
1768
1769         vi->nb.notifier_call = &virtnet_cpu_callback;
1770         err = register_hotcpu_notifier(&vi->nb);
1771         if (err) {
1772                 pr_debug("virtio_net: registering cpu notifier failed\n");
1773                 goto free_recv_bufs;
1774         }
1775
1776         /* Assume link up if device can't report link status,
1777            otherwise get link status from config. */
1778         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1779                 netif_carrier_off(dev);
1780                 schedule_work(&vi->config_work);
1781         } else {
1782                 vi->status = VIRTIO_NET_S_LINK_UP;
1783                 netif_carrier_on(dev);
1784         }
1785
1786         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1787                  dev->name, max_queue_pairs);
1788
1789         return 0;
1790
1791 free_recv_bufs:
1792         free_receive_bufs(vi);
1793         unregister_netdev(dev);
1794 free_vqs:
1795         cancel_delayed_work_sync(&vi->refill);
1796         free_receive_page_frags(vi);
1797         virtnet_del_vqs(vi);
1798 free_stats:
1799         free_percpu(vi->stats);
1800 free:
1801         free_netdev(dev);
1802         return err;
1803 }
1804
1805 static void remove_vq_common(struct virtnet_info *vi)
1806 {
1807         vi->vdev->config->reset(vi->vdev);
1808
1809         /* Free unused buffers in both send and recv, if any. */
1810         free_unused_bufs(vi);
1811
1812         free_receive_bufs(vi);
1813
1814         free_receive_page_frags(vi);
1815
1816         virtnet_del_vqs(vi);
1817 }
1818
1819 static void virtnet_remove(struct virtio_device *vdev)
1820 {
1821         struct virtnet_info *vi = vdev->priv;
1822
1823         unregister_hotcpu_notifier(&vi->nb);
1824
1825         /* Prevent config work handler from accessing the device. */
1826         mutex_lock(&vi->config_lock);
1827         vi->config_enable = false;
1828         mutex_unlock(&vi->config_lock);
1829
1830         unregister_netdev(vi->dev);
1831
1832         remove_vq_common(vi);
1833
1834         flush_work(&vi->config_work);
1835
1836         free_percpu(vi->stats);
1837         free_netdev(vi->dev);
1838 }
1839
1840 #ifdef CONFIG_PM_SLEEP
1841 static int virtnet_freeze(struct virtio_device *vdev)
1842 {
1843         struct virtnet_info *vi = vdev->priv;
1844         int i;
1845
1846         unregister_hotcpu_notifier(&vi->nb);
1847
1848         /* Prevent config work handler from accessing the device */
1849         mutex_lock(&vi->config_lock);
1850         vi->config_enable = false;
1851         mutex_unlock(&vi->config_lock);
1852
1853         netif_device_detach(vi->dev);
1854         cancel_delayed_work_sync(&vi->refill);
1855
1856         if (netif_running(vi->dev))
1857                 for (i = 0; i < vi->max_queue_pairs; i++) {
1858                         napi_disable(&vi->rq[i].napi);
1859                         netif_napi_del(&vi->rq[i].napi);
1860                 }
1861
1862         remove_vq_common(vi);
1863
1864         flush_work(&vi->config_work);
1865
1866         return 0;
1867 }
1868
1869 static int virtnet_restore(struct virtio_device *vdev)
1870 {
1871         struct virtnet_info *vi = vdev->priv;
1872         int err, i;
1873
1874         err = init_vqs(vi);
1875         if (err)
1876                 return err;
1877
1878         if (netif_running(vi->dev)) {
1879                 for (i = 0; i < vi->curr_queue_pairs; i++)
1880                         if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1881                                 schedule_delayed_work(&vi->refill, 0);
1882
1883                 for (i = 0; i < vi->max_queue_pairs; i++)
1884                         virtnet_napi_enable(&vi->rq[i]);
1885         }
1886
1887         netif_device_attach(vi->dev);
1888
1889         mutex_lock(&vi->config_lock);
1890         vi->config_enable = true;
1891         mutex_unlock(&vi->config_lock);
1892
1893         rtnl_lock();
1894         virtnet_set_queues(vi, vi->curr_queue_pairs);
1895         rtnl_unlock();
1896
1897         err = register_hotcpu_notifier(&vi->nb);
1898         if (err)
1899                 return err;
1900
1901         return 0;
1902 }
1903 #endif
1904
1905 static struct virtio_device_id id_table[] = {
1906         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1907         { 0 },
1908 };
1909
1910 static unsigned int features[] = {
1911         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1912         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1913         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1914         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1915         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1916         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1917         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1918         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1919         VIRTIO_NET_F_CTRL_MAC_ADDR,
1920         VIRTIO_F_ANY_LAYOUT,
1921 };
1922
1923 static struct virtio_driver virtio_net_driver = {
1924         .feature_table = features,
1925         .feature_table_size = ARRAY_SIZE(features),
1926         .driver.name =  KBUILD_MODNAME,
1927         .driver.owner = THIS_MODULE,
1928         .id_table =     id_table,
1929         .probe =        virtnet_probe,
1930         .remove =       virtnet_remove,
1931         .config_changed = virtnet_config_changed,
1932 #ifdef CONFIG_PM_SLEEP
1933         .freeze =       virtnet_freeze,
1934         .restore =      virtnet_restore,
1935 #endif
1936 };
1937
1938 module_virtio_driver(virtio_net_driver);
1939
1940 MODULE_DEVICE_TABLE(virtio, id_table);
1941 MODULE_DESCRIPTION("Virtio network driver");
1942 MODULE_LICENSE("GPL");