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                 {
 500                         static bool warned;
 501
 502                         if (!warned) {
 503                                 warned = true;
 504                                 netdev_warn(dev,
 505                                             "host using disabled UFO feature; please fix it\n");
 506                         }
 507                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 508                         break;
 509                 }
 510                 case VIRTIO_NET_HDR_GSO_TCPV6:
 511                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 512                         break;
 513                 default:
 514                         net_warn_ratelimited("%s: bad gso type %u.\n",
 515                                              dev->name, hdr->hdr.gso_type);
 516                         goto frame_err;
 517                 }
 518
 519                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 520                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 521
 522                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
 523                 if (skb_shinfo(skb)->gso_size == 0) {
 524                         net_warn_ratelimited("%s: zero gso size.\n", dev->name);
 525                         goto frame_err;
 526                 }
 527
 528                 /* Header must be checked, and gso_segs computed. */
 529                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 530                 skb_shinfo(skb)->gso_segs = 0;
 531         }
 532
 533         netif_receive_skb(skb);
 534         return;
 535
 536 frame_err:
 537         dev->stats.rx_frame_errors++;
 538         dev_kfree_skb(skb);
 539 }
 540
 541 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
 542 {
 543         struct virtnet_info *vi = rq->vq->vdev->priv;
 544         struct sk_buff *skb;
 545         struct skb_vnet_hdr *hdr;
 546         int err;
 547
 548         skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
 549         if (unlikely(!skb))
 550                 return -ENOMEM;
 551
 552         skb_put(skb, GOOD_PACKET_LEN);
 553
 554         hdr = skb_vnet_hdr(skb);
 555         sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
 556
 557         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 558
 559         err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
 560         if (err < 0)
 561                 dev_kfree_skb(skb);
 562
 563         return err;
 564 }
 565
 566 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
 567 {
 568         struct page *first, *list = NULL;
 569         char *p;
 570         int i, err, offset;
 571
 572         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 573         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 574                 first = get_a_page(rq, gfp);
 575                 if (!first) {
 576                         if (list)
 577                                 give_pages(rq, list);
 578                         return -ENOMEM;
 579                 }
 580                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
 581
 582                 /* chain new page in list head to match sg */
 583                 first->private = (unsigned long)list;
 584                 list = first;
 585         }
 586
 587         first = get_a_page(rq, gfp);
 588         if (!first) {
 589                 give_pages(rq, list);
 590                 return -ENOMEM;
 591         }
 592         p = page_address(first);
 593
 594         /* rq->sg[0], rq->sg[1] share the same page */
 595         /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
 596         sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
 597
 598         /* rq->sg[1] for data packet, from offset */
 599         offset = sizeof(struct padded_vnet_hdr);
 600         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
 601
 602         /* chain first in list head */
 603         first->private = (unsigned long)list;
 604         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
 605                                   first, gfp);
 606         if (err < 0)
 607                 give_pages(rq, first);
 608
 609         return err;
 610 }
 611
 612 static unsigned int get_mergeable_buf_len(struct ewma *avg_pkt_len)
 613 {
 614         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 615         unsigned int len;
 616
 617         len = hdr_len + clamp_t(unsigned int, ewma_read(avg_pkt_len),
 618                         GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
 619         return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
 620 }
 621
 622 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
 623 {
 624         struct page_frag *alloc_frag = &rq->alloc_frag;
 625         char *buf;
 626         unsigned long ctx;
 627         int err;
 628         unsigned int len, hole;
 629
 630         len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
 631         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
 632                 return -ENOMEM;
 633
 634         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
 635         ctx = mergeable_buf_to_ctx(buf, len);
 636         get_page(alloc_frag->page);
 637         alloc_frag->offset += len;
 638         hole = alloc_frag->size - alloc_frag->offset;
 639         if (hole < len) {
 640                 /* To avoid internal fragmentation, if there is very likely not
 641                  * enough space for another buffer, add the remaining space to
 642                  * the current buffer. This extra space is not included in
 643                  * the truesize stored in ctx.
 644                  */
 645                 len += hole;
 646                 alloc_frag->offset += hole;
 647         }
 648
 649         sg_init_one(rq->sg, buf, len);
 650         err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
 651         if (err < 0)
 652                 put_page(virt_to_head_page(buf));
 653
 654         return err;
 655 }
 656
 657 /*
 658  * Returns false if we couldn't fill entirely (OOM).
 659  *
 660  * Normally run in the receive path, but can also be run from ndo_open
 661  * before we're receiving packets, or from refill_work which is
 662  * careful to disable receiving (using napi_disable).
 663  */
 664 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
 665 {
 666         struct virtnet_info *vi = rq->vq->vdev->priv;
 667         int err;
 668         bool oom;
 669
 670         gfp |= __GFP_COLD;
 671         do {
 672                 if (vi->mergeable_rx_bufs)
 673                         err = add_recvbuf_mergeable(rq, gfp);
 674                 else if (vi->big_packets)
 675                         err = add_recvbuf_big(rq, gfp);
 676                 else
 677                         err = add_recvbuf_small(rq, gfp);
 678
 679                 oom = err == -ENOMEM;
 680                 if (err)
 681                         break;
 682         } while (rq->vq->num_free);
 683         virtqueue_kick(rq->vq);
 684         return !oom;
 685 }
 686
 687 static void skb_recv_done(struct virtqueue *rvq)
 688 {
 689         struct virtnet_info *vi = rvq->vdev->priv;
 690         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 691
 692         /* Schedule NAPI, Suppress further interrupts if successful. */
 693         if (napi_schedule_prep(&rq->napi)) {
 694                 virtqueue_disable_cb(rvq);
 695                 __napi_schedule(&rq->napi);
 696         }
 697 }
 698
 699 static void virtnet_napi_enable(struct receive_queue *rq)
 700 {
 701         napi_enable(&rq->napi);
 702
 703         /* If all buffers were filled by other side before we napi_enabled, we
 704          * won't get another interrupt, so process any outstanding packets
 705          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 706          * We synchronize against interrupts via NAPI_STATE_SCHED */
 707         if (napi_schedule_prep(&rq->napi)) {
 708                 virtqueue_disable_cb(rq->vq);
 709                 local_bh_disable();
 710                 __napi_schedule(&rq->napi);
 711                 local_bh_enable();
 712         }
 713 }
 714
 715 static void refill_work(struct work_struct *work)
 716 {
 717         struct virtnet_info *vi =
 718                 container_of(work, struct virtnet_info, refill.work);
 719         bool still_empty;
 720         int i;
 721
 722         for (i = 0; i < vi->curr_queue_pairs; i++) {
 723                 struct receive_queue *rq = &vi->rq[i];
 724
 725                 napi_disable(&rq->napi);
 726                 still_empty = !try_fill_recv(rq, GFP_KERNEL);
 727                 virtnet_napi_enable(rq);
 728
 729                 /* In theory, this can happen: if we don't get any buffers in
 730                  * we will *never* try to fill again.
 731                  */
 732                 if (still_empty)
 733                         schedule_delayed_work(&vi->refill, HZ/2);
 734         }
 735 }
 736
 737 static int virtnet_poll(struct napi_struct *napi, int budget)
 738 {
 739         struct receive_queue *rq =
 740                 container_of(napi, struct receive_queue, napi);
 741         struct virtnet_info *vi = rq->vq->vdev->priv;
 742         void *buf;
 743         unsigned int r, len, received = 0;
 744
 745 again:
 746         while (received < budget &&
 747                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
 748                 receive_buf(rq, buf, len);
 749                 received++;
 750         }
 751
 752         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
 753                 if (!try_fill_recv(rq, GFP_ATOMIC))
 754                         schedule_delayed_work(&vi->refill, 0);
 755         }
 756
 757         /* Out of packets? */
 758         if (received < budget) {
 759                 r = virtqueue_enable_cb_prepare(rq->vq);
 760                 napi_complete(napi);
 761                 if (unlikely(virtqueue_poll(rq->vq, r)) &&
 762                     napi_schedule_prep(napi)) {
 763                         virtqueue_disable_cb(rq->vq);
 764                         __napi_schedule(napi);
 765                         goto again;
 766                 }
 767         }
 768
 769         return received;
 770 }
 771
 772 static int virtnet_open(struct net_device *dev)
 773 {
 774         struct virtnet_info *vi = netdev_priv(dev);
 775         int i;
 776
 777         for (i = 0; i < vi->max_queue_pairs; i++) {
 778                 if (i < vi->curr_queue_pairs)
 779                         /* Make sure we have some buffers: if oom use wq. */
 780                         if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
 781                                 schedule_delayed_work(&vi->refill, 0);
 782                 virtnet_napi_enable(&vi->rq[i]);
 783         }
 784
 785         return 0;
 786 }
 787
 788 static void free_old_xmit_skbs(struct send_queue *sq)
 789 {
 790         struct sk_buff *skb;
 791         unsigned int len;
 792         struct virtnet_info *vi = sq->vq->vdev->priv;
 793         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 794
 795         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 796                 pr_debug("Sent skb %p\n", skb);
 797
 798                 u64_stats_update_begin(&stats->tx_syncp);
 799                 stats->tx_bytes += skb->len;
 800                 stats->tx_packets++;
 801                 u64_stats_update_end(&stats->tx_syncp);
 802
 803                 dev_kfree_skb_any(skb);
 804         }
 805 }
 806
 807 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 808 {
 809         struct skb_vnet_hdr *hdr;
 810         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 811         struct virtnet_info *vi = sq->vq->vdev->priv;
 812         unsigned num_sg;
 813         unsigned hdr_len;
 814         bool can_push;
 815
 816         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 817         if (vi->mergeable_rx_bufs)
 818                 hdr_len = sizeof hdr->mhdr;
 819         else
 820                 hdr_len = sizeof hdr->hdr;
 821
 822         can_push = vi->any_header_sg &&
 823                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
 824                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
 825         /* Even if we can, don't push here yet as this would skew
 826          * csum_start offset below. */
 827         if (can_push)
 828                 hdr = (struct skb_vnet_hdr *)(skb->data - hdr_len);
 829         else
 830                 hdr = skb_vnet_hdr(skb);
 831
 832         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 833                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 834                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
 835                 hdr->hdr.csum_offset = skb->csum_offset;
 836         } else {
 837                 hdr->hdr.flags = 0;
 838                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 839         }
 840
 841         if (skb_is_gso(skb)) {
 842                 hdr->hdr.hdr_len = skb_headlen(skb);
 843                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
 844                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 845                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 846                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 847                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 848                 else
 849                         BUG();
 850                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 851                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 852         } else {
 853                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 854                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
 855         }
 856
 857         if (vi->mergeable_rx_bufs)
 858                 hdr->mhdr.num_buffers = 0;
 859
 860         if (can_push) {
 861                 __skb_push(skb, hdr_len);
 862                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
 863                 /* Pull header back to avoid skew in tx bytes calculations. */
 864                 __skb_pull(skb, hdr_len);
 865         } else {
 866                 sg_set_buf(sq->sg, hdr, hdr_len);
 867                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
 868         }
 869         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
 870 }
 871
 872 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 873 {
 874         struct virtnet_info *vi = netdev_priv(dev);
 875         int qnum = skb_get_queue_mapping(skb);
 876         struct send_queue *sq = &vi->sq[qnum];
 877         int err;
 878
 879         /* Free up any pending old buffers before queueing new ones. */
 880         free_old_xmit_skbs(sq);
 881
 882         /* Try to transmit */
 883         err = xmit_skb(sq, skb);
 884
 885         /* This should not happen! */
 886         if (unlikely(err)) {
 887                 dev->stats.tx_fifo_errors++;
 888                 if (net_ratelimit())
 889                         dev_warn(&dev->dev,
 890                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
 891                 dev->stats.tx_dropped++;
 892                 kfree_skb(skb);
 893                 return NETDEV_TX_OK;
 894         }
 895         virtqueue_kick(sq->vq);
 896
 897         /* Don't wait up for transmitted skbs to be freed. */
 898         skb_orphan(skb);
 899         nf_reset(skb);
 900
 901         /* Apparently nice girls don't return TX_BUSY; stop the queue
 902          * before it gets out of hand.  Naturally, this wastes entries. */
 903         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
 904                 netif_stop_subqueue(dev, qnum);
 905                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 906                         /* More just got used, free them then recheck. */
 907                         free_old_xmit_skbs(sq);
 908                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
 909                                 netif_start_subqueue(dev, qnum);
 910                                 virtqueue_disable_cb(sq->vq);
 911                         }
 912                 }
 913         }
 914
 915         return NETDEV_TX_OK;
 916 }
 917
 918 /*
 919  * Send command via the control virtqueue and check status.  Commands
 920  * supported by the hypervisor, as indicated by feature bits, should
 921  * never fail unless improperly formatted.
 922  */
 923 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 924                                  struct scatterlist *out)
 925 {
 926         struct scatterlist *sgs[4], hdr, stat;
 927         struct virtio_net_ctrl_hdr ctrl;
 928         virtio_net_ctrl_ack status = ~0;
 929         unsigned out_num = 0, tmp;
 930
 931         /* Caller should know better */
 932         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
 933
 934         ctrl.class = class;
 935         ctrl.cmd = cmd;
 936         /* Add header */
 937         sg_init_one(&hdr, &ctrl, sizeof(ctrl));
 938         sgs[out_num++] = &hdr;
 939
 940         if (out)
 941                 sgs[out_num++] = out;
 942
 943         /* Add return status. */
 944         sg_init_one(&stat, &status, sizeof(status));
 945         sgs[out_num] = &stat;
 946
 947         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
 948         BUG_ON(virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC) < 0);
 949
 950         if (unlikely(!virtqueue_kick(vi->cvq)))
 951                 return status == VIRTIO_NET_OK;
 952
 953         /* Spin for a response, the kick causes an ioport write, trapping
 954          * into the hypervisor, so the request should be handled immediately.
 955          */
 956         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
 957                !virtqueue_is_broken(vi->cvq))
 958                 cpu_relax();
 959
 960         return status == VIRTIO_NET_OK;
 961 }
 962
 963 static int virtnet_set_mac_address(struct net_device *dev, void *p)
 964 {
 965         struct virtnet_info *vi = netdev_priv(dev);
 966         struct virtio_device *vdev = vi->vdev;
 967         int ret;
 968         struct sockaddr *addr = p;
 969         struct scatterlist sg;
 970
 971         ret = eth_prepare_mac_addr_change(dev, p);
 972         if (ret)
 973                 return ret;
 974
 975         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
 976                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
 977                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
 978                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
 979                         dev_warn(&vdev->dev,
 980                                  "Failed to set mac address by vq command.\n");
 981                         return -EINVAL;
 982                 }
 983         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
 984                 unsigned int i;
 985
 986                 /* Naturally, this has an atomicity problem. */
 987                 for (i = 0; i < dev->addr_len; i++)
 988                         virtio_cwrite8(vdev,
 989                                        offsetof(struct virtio_net_config, mac) +
 990                                        i, addr->sa_data[i]);
 991         }
 992
 993         eth_commit_mac_addr_change(dev, p);
 994
 995         return 0;
 996 }
 997
 998 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
 999                                                struct rtnl_link_stats64 *tot)
1000 {
1001         struct virtnet_info *vi = netdev_priv(dev);
1002         int cpu;
1003         unsigned int start;
1004
1005         for_each_possible_cpu(cpu) {
1006                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1007                 u64 tpackets, tbytes, rpackets, rbytes;
1008
1009                 do {
1010                         start = u64_stats_fetch_begin_bh(&stats->tx_syncp);
1011                         tpackets = stats->tx_packets;
1012                         tbytes   = stats->tx_bytes;
1013                 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start));
1014
1015                 do {
1016                         start = u64_stats_fetch_begin_bh(&stats->rx_syncp);
1017                         rpackets = stats->rx_packets;
1018                         rbytes   = stats->rx_bytes;
1019                 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start));
1020
1021                 tot->rx_packets += rpackets;
1022                 tot->tx_packets += tpackets;
1023                 tot->rx_bytes   += rbytes;
1024                 tot->tx_bytes   += tbytes;
1025         }
1026
1027         tot->tx_dropped = dev->stats.tx_dropped;
1028         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1029         tot->rx_dropped = dev->stats.rx_dropped;
1030         tot->rx_length_errors = dev->stats.rx_length_errors;
1031         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1032
1033         return tot;
1034 }
1035
1036 #ifdef CONFIG_NET_POLL_CONTROLLER
1037 static void virtnet_netpoll(struct net_device *dev)
1038 {
1039         struct virtnet_info *vi = netdev_priv(dev);
1040         int i;
1041
1042         for (i = 0; i < vi->curr_queue_pairs; i++)
1043                 napi_schedule(&vi->rq[i].napi);
1044 }
1045 #endif
1046
1047 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1048 {
1049         rtnl_lock();
1050         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1051                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1052                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1053         rtnl_unlock();
1054 }
1055
1056 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1057 {
1058         struct scatterlist sg;
1059         struct virtio_net_ctrl_mq s;
1060         struct net_device *dev = vi->dev;
1061
1062         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1063                 return 0;
1064
1065         s.virtqueue_pairs = queue_pairs;
1066         sg_init_one(&sg, &s, sizeof(s));
1067
1068         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1069                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1070                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1071                          queue_pairs);
1072                 return -EINVAL;
1073         } else {
1074                 vi->curr_queue_pairs = queue_pairs;
1075                 /* virtnet_open() will refill when device is going to up. */
1076                 if (dev->flags & IFF_UP)
1077                         schedule_delayed_work(&vi->refill, 0);
1078         }
1079
1080         return 0;
1081 }
1082
1083 static int virtnet_close(struct net_device *dev)
1084 {
1085         struct virtnet_info *vi = netdev_priv(dev);
1086         int i;
1087
1088         /* Make sure refill_work doesn't re-enable napi! */
1089         cancel_delayed_work_sync(&vi->refill);
1090
1091         for (i = 0; i < vi->max_queue_pairs; i++)
1092                 napi_disable(&vi->rq[i].napi);
1093
1094         return 0;
1095 }
1096
1097 static void virtnet_set_rx_mode(struct net_device *dev)
1098 {
1099         struct virtnet_info *vi = netdev_priv(dev);
1100         struct scatterlist sg[2];
1101         u8 promisc, allmulti;
1102         struct virtio_net_ctrl_mac *mac_data;
1103         struct netdev_hw_addr *ha;
1104         int uc_count;
1105         int mc_count;
1106         void *buf;
1107         int i;
1108
1109         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1110         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1111                 return;
1112
1113         promisc = ((dev->flags & IFF_PROMISC) != 0);
1114         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1115
1116         sg_init_one(sg, &promisc, sizeof(promisc));
1117
1118         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1119                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1120                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1121                          promisc ? "en" : "dis");
1122
1123         sg_init_one(sg, &allmulti, sizeof(allmulti));
1124
1125         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1126                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1127                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1128                          allmulti ? "en" : "dis");
1129
1130         uc_count = netdev_uc_count(dev);
1131         mc_count = netdev_mc_count(dev);
1132         /* MAC filter - use one buffer for both lists */
1133         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1134                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1135         mac_data = buf;
1136         if (!buf)
1137                 return;
1138
1139         sg_init_table(sg, 2);
1140
1141         /* Store the unicast list and count in the front of the buffer */
1142         mac_data->entries = uc_count;
1143         i = 0;
1144         netdev_for_each_uc_addr(ha, dev)
1145                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1146
1147         sg_set_buf(&sg[0], mac_data,
1148                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1149
1150         /* multicast list and count fill the end */
1151         mac_data = (void *)&mac_data->macs[uc_count][0];
1152
1153         mac_data->entries = mc_count;
1154         i = 0;
1155         netdev_for_each_mc_addr(ha, dev)
1156                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1157
1158         sg_set_buf(&sg[1], mac_data,
1159                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1160
1161         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1162                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1163                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1164
1165         kfree(buf);
1166 }
1167
1168 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1169                                    __be16 proto, u16 vid)
1170 {
1171         struct virtnet_info *vi = netdev_priv(dev);
1172         struct scatterlist sg;
1173
1174         sg_init_one(&sg, &vid, sizeof(vid));
1175
1176         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1177                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1178                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1179         return 0;
1180 }
1181
1182 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1183                                     __be16 proto, u16 vid)
1184 {
1185         struct virtnet_info *vi = netdev_priv(dev);
1186         struct scatterlist sg;
1187
1188         sg_init_one(&sg, &vid, sizeof(vid));
1189
1190         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1191                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1192                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1193         return 0;
1194 }
1195
1196 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1197 {
1198         int i;
1199
1200         if (vi->affinity_hint_set) {
1201                 for (i = 0; i < vi->max_queue_pairs; i++) {
1202                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1203                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1204                 }
1205
1206                 vi->affinity_hint_set = false;
1207         }
1208 }
1209
1210 static void virtnet_set_affinity(struct virtnet_info *vi)
1211 {
1212         int i;
1213         int cpu;
1214
1215         /* In multiqueue mode, when the number of cpu is equal to the number of
1216          * queue pairs, we let the queue pairs to be private to one cpu by
1217          * setting the affinity hint to eliminate the contention.
1218          */
1219         if (vi->curr_queue_pairs == 1 ||
1220             vi->max_queue_pairs != num_online_cpus()) {
1221                 virtnet_clean_affinity(vi, -1);
1222                 return;
1223         }
1224
1225         i = 0;
1226         for_each_online_cpu(cpu) {
1227                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1228                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1229                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1230                 i++;
1231         }
1232
1233         vi->affinity_hint_set = true;
1234 }
1235
1236 static int virtnet_cpu_callback(struct notifier_block *nfb,
1237                                 unsigned long action, void *hcpu)
1238 {
1239         struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);
1240
1241         switch(action & ~CPU_TASKS_FROZEN) {
1242         case CPU_ONLINE:
1243         case CPU_DOWN_FAILED:
1244         case CPU_DEAD:
1245                 virtnet_set_affinity(vi);
1246                 break;
1247         case CPU_DOWN_PREPARE:
1248                 virtnet_clean_affinity(vi, (long)hcpu);
1249                 break;
1250         default:
1251                 break;
1252         }
1253
1254         return NOTIFY_OK;
1255 }
1256
1257 static void virtnet_get_ringparam(struct net_device *dev,
1258                                 struct ethtool_ringparam *ring)
1259 {
1260         struct virtnet_info *vi = netdev_priv(dev);
1261
1262         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1263         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1264         ring->rx_pending = ring->rx_max_pending;
1265         ring->tx_pending = ring->tx_max_pending;
1266 }
1267
1268
1269 static void virtnet_get_drvinfo(struct net_device *dev,
1270                                 struct ethtool_drvinfo *info)
1271 {
1272         struct virtnet_info *vi = netdev_priv(dev);
1273         struct virtio_device *vdev = vi->vdev;
1274
1275         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1276         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1277         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1278
1279 }
1280
1281 /* TODO: Eliminate OOO packets during switching */
1282 static int virtnet_set_channels(struct net_device *dev,
1283                                 struct ethtool_channels *channels)
1284 {
1285         struct virtnet_info *vi = netdev_priv(dev);
1286         u16 queue_pairs = channels->combined_count;
1287         int err;
1288
1289         /* We don't support separate rx/tx channels.
1290          * We don't allow setting 'other' channels.
1291          */
1292         if (channels->rx_count || channels->tx_count || channels->other_count)
1293                 return -EINVAL;
1294
1295         if (queue_pairs > vi->max_queue_pairs)
1296                 return -EINVAL;
1297
1298         get_online_cpus();
1299         err = virtnet_set_queues(vi, queue_pairs);
1300         if (!err) {
1301                 netif_set_real_num_tx_queues(dev, queue_pairs);
1302                 netif_set_real_num_rx_queues(dev, queue_pairs);
1303
1304                 virtnet_set_affinity(vi);
1305         }
1306         put_online_cpus();
1307
1308         return err;
1309 }
1310
1311 static void virtnet_get_channels(struct net_device *dev,
1312                                  struct ethtool_channels *channels)
1313 {
1314         struct virtnet_info *vi = netdev_priv(dev);
1315
1316         channels->combined_count = vi->curr_queue_pairs;
1317         channels->max_combined = vi->max_queue_pairs;
1318         channels->max_other = 0;
1319         channels->rx_count = 0;
1320         channels->tx_count = 0;
1321         channels->other_count = 0;
1322 }
1323
1324 static const struct ethtool_ops virtnet_ethtool_ops = {
1325         .get_drvinfo = virtnet_get_drvinfo,
1326         .get_link = ethtool_op_get_link,
1327         .get_ringparam = virtnet_get_ringparam,
1328         .set_channels = virtnet_set_channels,
1329         .get_channels = virtnet_get_channels,
1330 };
1331
1332 #define MIN_MTU 68
1333 #define MAX_MTU 65535
1334
1335 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1336 {
1337         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1338                 return -EINVAL;
1339         dev->mtu = new_mtu;
1340         return 0;
1341 }
1342
1343 static const struct net_device_ops virtnet_netdev = {
1344         .ndo_open            = virtnet_open,
1345         .ndo_stop            = virtnet_close,
1346         .ndo_start_xmit      = start_xmit,
1347         .ndo_validate_addr   = eth_validate_addr,
1348         .ndo_set_mac_address = virtnet_set_mac_address,
1349         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1350         .ndo_change_mtu      = virtnet_change_mtu,
1351         .ndo_get_stats64     = virtnet_stats,
1352         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1353         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1354 #ifdef CONFIG_NET_POLL_CONTROLLER
1355         .ndo_poll_controller = virtnet_netpoll,
1356 #endif
1357 };
1358
1359 static void virtnet_config_changed_work(struct work_struct *work)
1360 {
1361         struct virtnet_info *vi =
1362                 container_of(work, struct virtnet_info, config_work);
1363         u16 v;
1364
1365         mutex_lock(&vi->config_lock);
1366         if (!vi->config_enable)
1367                 goto done;
1368
1369         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
1370                                  struct virtio_net_config, status, &v) < 0)
1371                 goto done;
1372
1373         if (v & VIRTIO_NET_S_ANNOUNCE) {
1374                 netdev_notify_peers(vi->dev);
1375                 virtnet_ack_link_announce(vi);
1376         }
1377
1378         /* Ignore unknown (future) status bits */
1379         v &= VIRTIO_NET_S_LINK_UP;
1380
1381         if (vi->status == v)
1382                 goto done;
1383
1384         vi->status = v;
1385
1386         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1387                 netif_carrier_on(vi->dev);
1388                 netif_tx_wake_all_queues(vi->dev);
1389         } else {
1390                 netif_carrier_off(vi->dev);
1391                 netif_tx_stop_all_queues(vi->dev);
1392         }
1393 done:
1394         mutex_unlock(&vi->config_lock);
1395 }
1396
1397 static void virtnet_config_changed(struct virtio_device *vdev)
1398 {
1399         struct virtnet_info *vi = vdev->priv;
1400
1401         schedule_work(&vi->config_work);
1402 }
1403
1404 static void virtnet_free_queues(struct virtnet_info *vi)
1405 {
1406         int i;
1407
1408         for (i = 0; i < vi->max_queue_pairs; i++)
1409                 netif_napi_del(&vi->rq[i].napi);
1410
1411         kfree(vi->rq);
1412         kfree(vi->sq);
1413 }
1414
1415 static void free_receive_bufs(struct virtnet_info *vi)
1416 {
1417         int i;
1418
1419         for (i = 0; i < vi->max_queue_pairs; i++) {
1420                 while (vi->rq[i].pages)
1421                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1422         }
1423 }
1424
1425 static void free_receive_page_frags(struct virtnet_info *vi)
1426 {
1427         int i;
1428         for (i = 0; i < vi->max_queue_pairs; i++)
1429                 if (vi->rq[i].alloc_frag.page)
1430                         put_page(vi->rq[i].alloc_frag.page);
1431 }
1432
1433 static void free_unused_bufs(struct virtnet_info *vi)
1434 {
1435         void *buf;
1436         int i;
1437
1438         for (i = 0; i < vi->max_queue_pairs; i++) {
1439                 struct virtqueue *vq = vi->sq[i].vq;
1440                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1441                         dev_kfree_skb(buf);
1442         }
1443
1444         for (i = 0; i < vi->max_queue_pairs; i++) {
1445                 struct virtqueue *vq = vi->rq[i].vq;
1446
1447                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1448                         if (vi->mergeable_rx_bufs) {
1449                                 unsigned long ctx = (unsigned long)buf;
1450                                 void *base = mergeable_ctx_to_buf_address(ctx);
1451                                 put_page(virt_to_head_page(base));
1452                         } else if (vi->big_packets) {
1453                                 give_pages(&vi->rq[i], buf);
1454                         } else {
1455                                 dev_kfree_skb(buf);
1456                         }
1457                 }
1458         }
1459 }
1460
1461 static void virtnet_del_vqs(struct virtnet_info *vi)
1462 {
1463         struct virtio_device *vdev = vi->vdev;
1464
1465         virtnet_clean_affinity(vi, -1);
1466
1467         vdev->config->del_vqs(vdev);
1468
1469         virtnet_free_queues(vi);
1470 }
1471
1472 static int virtnet_find_vqs(struct virtnet_info *vi)
1473 {
1474         vq_callback_t **callbacks;
1475         struct virtqueue **vqs;
1476         int ret = -ENOMEM;
1477         int i, total_vqs;
1478         const char **names;
1479
1480         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1481          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1482          * possible control vq.
1483          */
1484         total_vqs = vi->max_queue_pairs * 2 +
1485                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1486
1487         /* Allocate space for find_vqs parameters */
1488         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1489         if (!vqs)
1490                 goto err_vq;
1491         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1492         if (!callbacks)
1493                 goto err_callback;
1494         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1495         if (!names)
1496                 goto err_names;
1497
1498         /* Parameters for control virtqueue, if any */
1499         if (vi->has_cvq) {
1500                 callbacks[total_vqs - 1] = NULL;
1501                 names[total_vqs - 1] = "control";
1502         }
1503
1504         /* Allocate/initialize parameters for send/receive virtqueues */
1505         for (i = 0; i < vi->max_queue_pairs; i++) {
1506                 callbacks[rxq2vq(i)] = skb_recv_done;
1507                 callbacks[txq2vq(i)] = skb_xmit_done;
1508                 sprintf(vi->rq[i].name, "input.%d", i);
1509                 sprintf(vi->sq[i].name, "output.%d", i);
1510                 names[rxq2vq(i)] = vi->rq[i].name;
1511                 names[txq2vq(i)] = vi->sq[i].name;
1512         }
1513
1514         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1515                                          names);
1516         if (ret)
1517                 goto err_find;
1518
1519         if (vi->has_cvq) {
1520                 vi->cvq = vqs[total_vqs - 1];
1521                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1522                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1523         }
1524
1525         for (i = 0; i < vi->max_queue_pairs; i++) {
1526                 vi->rq[i].vq = vqs[rxq2vq(i)];
1527                 vi->sq[i].vq = vqs[txq2vq(i)];
1528         }
1529
1530         kfree(names);
1531         kfree(callbacks);
1532         kfree(vqs);
1533
1534         return 0;
1535
1536 err_find:
1537         kfree(names);
1538 err_names:
1539         kfree(callbacks);
1540 err_callback:
1541         kfree(vqs);
1542 err_vq:
1543         return ret;
1544 }
1545
1546 static int virtnet_alloc_queues(struct virtnet_info *vi)
1547 {
1548         int i;
1549
1550         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1551         if (!vi->sq)
1552                 goto err_sq;
1553         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1554         if (!vi->rq)
1555                 goto err_rq;
1556
1557         INIT_DELAYED_WORK(&vi->refill, refill_work);
1558         for (i = 0; i < vi->max_queue_pairs; i++) {
1559                 vi->rq[i].pages = NULL;
1560                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1561                                napi_weight);
1562
1563                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1564                 ewma_init(&vi->rq[i].mrg_avg_pkt_len, 1, RECEIVE_AVG_WEIGHT);
1565                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1566         }
1567
1568         return 0;
1569
1570 err_rq:
1571         kfree(vi->sq);
1572 err_sq:
1573         return -ENOMEM;
1574 }
1575
1576 static int init_vqs(struct virtnet_info *vi)
1577 {
1578         int ret;
1579
1580         /* Allocate send & receive queues */
1581         ret = virtnet_alloc_queues(vi);
1582         if (ret)
1583                 goto err;
1584
1585         ret = virtnet_find_vqs(vi);
1586         if (ret)
1587                 goto err_free;
1588
1589         get_online_cpus();
1590         virtnet_set_affinity(vi);
1591         put_online_cpus();
1592
1593         return 0;
1594
1595 err_free:
1596         virtnet_free_queues(vi);
1597 err:
1598         return ret;
1599 }
1600
1601 #ifdef CONFIG_SYSFS
1602 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
1603                 struct rx_queue_attribute *attribute, char *buf)
1604 {
1605         struct virtnet_info *vi = netdev_priv(queue->dev);
1606         unsigned int queue_index = get_netdev_rx_queue_index(queue);
1607         struct ewma *avg;
1608
1609         BUG_ON(queue_index >= vi->max_queue_pairs);
1610         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
1611         return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
1612 }
1613
1614 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
1615         __ATTR_RO(mergeable_rx_buffer_size);
1616
1617 static struct attribute *virtio_net_mrg_rx_attrs[] = {
1618         &mergeable_rx_buffer_size_attribute.attr,
1619         NULL
1620 };
1621
1622 static const struct attribute_group virtio_net_mrg_rx_group = {
1623         .name = "virtio_net",
1624         .attrs = virtio_net_mrg_rx_attrs
1625 };
1626 #endif
1627
1628 static int virtnet_probe(struct virtio_device *vdev)
1629 {
1630         int i, err;
1631         struct net_device *dev;
1632         struct virtnet_info *vi;
1633         u16 max_queue_pairs;
1634
1635         /* Find if host supports multiqueue virtio_net device */
1636         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
1637                                    struct virtio_net_config,
1638                                    max_virtqueue_pairs, &max_queue_pairs);
1639
1640         /* We need at least 2 queue's */
1641         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1642             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1643             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1644                 max_queue_pairs = 1;
1645
1646         /* Allocate ourselves a network device with room for our info */
1647         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1648         if (!dev)
1649                 return -ENOMEM;
1650
1651         /* Set up network device as normal. */
1652         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1653         dev->netdev_ops = &virtnet_netdev;
1654         dev->features = NETIF_F_HIGHDMA;
1655
1656         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1657         SET_NETDEV_DEV(dev, &vdev->dev);
1658
1659         /* Do we support "hardware" checksums? */
1660         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1661                 /* This opens up the world of extra features. */
1662                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1663                 if (csum)
1664                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1665
1666                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1667                         dev->hw_features |= NETIF_F_TSO
1668                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1669                 }
1670                 /* Individual feature bits: what can host handle? */
1671                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1672                         dev->hw_features |= NETIF_F_TSO;
1673                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1674                         dev->hw_features |= NETIF_F_TSO6;
1675                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1676                         dev->hw_features |= NETIF_F_TSO_ECN;
1677
1678                 if (gso)
1679                         dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
1680                 /* (!csum && gso) case will be fixed by register_netdev() */
1681         }
1682         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
1683                 dev->features |= NETIF_F_RXCSUM;
1684
1685         dev->vlan_features = dev->features;
1686
1687         /* Configuration may specify what MAC to use.  Otherwise random. */
1688         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
1689                 virtio_cread_bytes(vdev,
1690                                    offsetof(struct virtio_net_config, mac),
1691                                    dev->dev_addr, dev->addr_len);
1692         else
1693                 eth_hw_addr_random(dev);
1694
1695         /* Set up our device-specific information */
1696         vi = netdev_priv(dev);
1697         vi->dev = dev;
1698         vi->vdev = vdev;
1699         vdev->priv = vi;
1700         vi->stats = alloc_percpu(struct virtnet_stats);
1701         err = -ENOMEM;
1702         if (vi->stats == NULL)
1703                 goto free;
1704
1705         for_each_possible_cpu(i) {
1706                 struct virtnet_stats *virtnet_stats;
1707                 virtnet_stats = per_cpu_ptr(vi->stats, i);
1708                 u64_stats_init(&virtnet_stats->tx_syncp);
1709                 u64_stats_init(&virtnet_stats->rx_syncp);
1710         }
1711
1712         mutex_init(&vi->config_lock);
1713         vi->config_enable = true;
1714         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1715
1716         /* If we can receive ANY GSO packets, we must allocate large ones. */
1717         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1718             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1719             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1720                 vi->big_packets = true;
1721
1722         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1723                 vi->mergeable_rx_bufs = true;
1724
1725         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT))
1726                 vi->any_header_sg = true;
1727
1728         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1729                 vi->has_cvq = true;
1730
1731         /* Use single tx/rx queue pair as default */
1732         vi->curr_queue_pairs = 1;
1733         vi->max_queue_pairs = max_queue_pairs;
1734
1735         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1736         err = init_vqs(vi);
1737         if (err)
1738                 goto free_stats;
1739
1740 #ifdef CONFIG_SYSFS
1741         if (vi->mergeable_rx_bufs)
1742                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
1743 #endif
1744         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
1745         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
1746
1747         err = register_netdev(dev);
1748         if (err) {
1749                 pr_debug("virtio_net: registering device failed\n");
1750                 goto free_vqs;
1751         }
1752
1753         /* Last of all, set up some receive buffers. */
1754         for (i = 0; i < vi->curr_queue_pairs; i++) {
1755                 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1756
1757                 /* If we didn't even get one input buffer, we're useless. */
1758                 if (vi->rq[i].vq->num_free ==
1759                     virtqueue_get_vring_size(vi->rq[i].vq)) {
1760                         free_unused_bufs(vi);
1761                         err = -ENOMEM;
1762                         goto free_recv_bufs;
1763                 }
1764         }
1765
1766         vi->nb.notifier_call = &virtnet_cpu_callback;
1767         err = register_hotcpu_notifier(&vi->nb);
1768         if (err) {
1769                 pr_debug("virtio_net: registering cpu notifier failed\n");
1770                 goto free_recv_bufs;
1771         }
1772
1773         /* Assume link up if device can't report link status,
1774            otherwise get link status from config. */
1775         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1776                 netif_carrier_off(dev);
1777                 schedule_work(&vi->config_work);
1778         } else {
1779                 vi->status = VIRTIO_NET_S_LINK_UP;
1780                 netif_carrier_on(dev);
1781         }
1782
1783         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1784                  dev->name, max_queue_pairs);
1785
1786         return 0;
1787
1788 free_recv_bufs:
1789         free_receive_bufs(vi);
1790         unregister_netdev(dev);
1791 free_vqs:
1792         cancel_delayed_work_sync(&vi->refill);
1793         free_receive_page_frags(vi);
1794         virtnet_del_vqs(vi);
1795 free_stats:
1796         free_percpu(vi->stats);
1797 free:
1798         free_netdev(dev);
1799         return err;
1800 }
1801
1802 static void remove_vq_common(struct virtnet_info *vi)
1803 {
1804         vi->vdev->config->reset(vi->vdev);
1805
1806         /* Free unused buffers in both send and recv, if any. */
1807         free_unused_bufs(vi);
1808
1809         free_receive_bufs(vi);
1810
1811         free_receive_page_frags(vi);
1812
1813         virtnet_del_vqs(vi);
1814 }
1815
1816 static void virtnet_remove(struct virtio_device *vdev)
1817 {
1818         struct virtnet_info *vi = vdev->priv;
1819
1820         unregister_hotcpu_notifier(&vi->nb);
1821
1822         /* Prevent config work handler from accessing the device. */
1823         mutex_lock(&vi->config_lock);
1824         vi->config_enable = false;
1825         mutex_unlock(&vi->config_lock);
1826
1827         unregister_netdev(vi->dev);
1828
1829         remove_vq_common(vi);
1830
1831         flush_work(&vi->config_work);
1832
1833         free_percpu(vi->stats);
1834         free_netdev(vi->dev);
1835 }
1836
1837 #ifdef CONFIG_PM_SLEEP
1838 static int virtnet_freeze(struct virtio_device *vdev)
1839 {
1840         struct virtnet_info *vi = vdev->priv;
1841         int i;
1842
1843         unregister_hotcpu_notifier(&vi->nb);
1844
1845         /* Prevent config work handler from accessing the device */
1846         mutex_lock(&vi->config_lock);
1847         vi->config_enable = false;
1848         mutex_unlock(&vi->config_lock);
1849
1850         netif_device_detach(vi->dev);
1851         cancel_delayed_work_sync(&vi->refill);
1852
1853         if (netif_running(vi->dev))
1854                 for (i = 0; i < vi->max_queue_pairs; i++) {
1855                         napi_disable(&vi->rq[i].napi);
1856                         netif_napi_del(&vi->rq[i].napi);
1857                 }
1858
1859         remove_vq_common(vi);
1860
1861         flush_work(&vi->config_work);
1862
1863         return 0;
1864 }
1865
1866 static int virtnet_restore(struct virtio_device *vdev)
1867 {
1868         struct virtnet_info *vi = vdev->priv;
1869         int err, i;
1870
1871         err = init_vqs(vi);
1872         if (err)
1873                 return err;
1874
1875         if (netif_running(vi->dev)) {
1876                 for (i = 0; i < vi->curr_queue_pairs; i++)
1877                         if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1878                                 schedule_delayed_work(&vi->refill, 0);
1879
1880                 for (i = 0; i < vi->max_queue_pairs; i++)
1881                         virtnet_napi_enable(&vi->rq[i]);
1882         }
1883
1884         netif_device_attach(vi->dev);
1885
1886         mutex_lock(&vi->config_lock);
1887         vi->config_enable = true;
1888         mutex_unlock(&vi->config_lock);
1889
1890         rtnl_lock();
1891         virtnet_set_queues(vi, vi->curr_queue_pairs);
1892         rtnl_unlock();
1893
1894         err = register_hotcpu_notifier(&vi->nb);
1895         if (err)
1896                 return err;
1897
1898         return 0;
1899 }
1900 #endif
1901
1902 static struct virtio_device_id id_table[] = {
1903         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1904         { 0 },
1905 };
1906
1907 static unsigned int features[] = {
1908         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1909         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1910         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_TSO6,
1911         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1912         VIRTIO_NET_F_GUEST_ECN,
1913         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1914         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1915         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1916         VIRTIO_NET_F_CTRL_MAC_ADDR,
1917         VIRTIO_F_ANY_LAYOUT,
1918 };
1919
1920 static struct virtio_driver virtio_net_driver = {
1921         .feature_table = features,
1922         .feature_table_size = ARRAY_SIZE(features),
1923         .driver.name =  KBUILD_MODNAME,
1924         .driver.owner = THIS_MODULE,
1925         .id_table =     id_table,
1926         .probe =        virtnet_probe,
1927         .remove =       virtnet_remove,
1928         .config_changed = virtnet_config_changed,
1929 #ifdef CONFIG_PM_SLEEP
1930         .freeze =       virtnet_freeze,
1931         .restore =      virtnet_restore,
1932 #endif
1933 };
1934
1935 module_virtio_driver(virtio_net_driver);
1936
1937 MODULE_DEVICE_TABLE(virtio, id_table);
1938 MODULE_DESCRIPTION("Virtio network driver");
1939 MODULE_LICENSE("GPL");