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 #include <net/busy_poll.h>
  31
  32 static int napi_weight = NAPI_POLL_WEIGHT;
  33 module_param(napi_weight, int, 0444);
  34
  35 static bool csum = true, gso = true;
  36 module_param(csum, bool, 0444);
  37 module_param(gso, bool, 0444);
  38
  39 /* FIXME: MTU in config. */
  40 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  41 #define GOOD_COPY_LEN   128
  42
  43 /* Weight used for the RX packet size EWMA. The average packet size is used to
  44  * determine the packet buffer size when refilling RX rings. As the entire RX
  45  * ring may be refilled at once, the weight is chosen so that the EWMA will be
  46  * insensitive to short-term, transient changes in packet size.
  47  */
  48 #define RECEIVE_AVG_WEIGHT 64
  49
  50 /* Minimum alignment for mergeable packet buffers. */
  51 #define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
  52
  53 #define VIRTNET_DRIVER_VERSION "1.0.0"
  54
  55 struct virtnet_stats {
  56         struct u64_stats_sync tx_syncp;
  57         struct u64_stats_sync rx_syncp;
  58         u64 tx_bytes;
  59         u64 tx_packets;
  60
  61         u64 rx_bytes;
  62         u64 rx_packets;
  63 };
  64
  65 /* Internal representation of a send virtqueue */
  66 struct send_queue {
  67         /* Virtqueue associated with this send _queue */
  68         struct virtqueue *vq;
  69
  70         /* TX: fragments + linear part + virtio header */
  71         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  72
  73         /* Name of the send queue: output.$index */
  74         char name[40];
  75 };
  76
  77 /* Internal representation of a receive virtqueue */
  78 struct receive_queue {
  79         /* Virtqueue associated with this receive_queue */
  80         struct virtqueue *vq;
  81
  82         struct napi_struct napi;
  83
  84         /* Chain pages by the private ptr. */
  85         struct page *pages;
  86
  87         /* Average packet length for mergeable receive buffers. */
  88         struct ewma mrg_avg_pkt_len;
  89
  90         /* Page frag for packet buffer allocation. */
  91         struct page_frag alloc_frag;
  92
  93         /* RX: fragments + linear part + virtio header */
  94         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  95
  96         /* Name of this receive queue: input.$index */
  97         char name[40];
  98 };
  99
 100 struct virtnet_info {
 101         struct virtio_device *vdev;
 102         struct virtqueue *cvq;
 103         struct net_device *dev;
 104         struct send_queue *sq;
 105         struct receive_queue *rq;
 106         unsigned int status;
 107
 108         /* Max # of queue pairs supported by the device */
 109         u16 max_queue_pairs;
 110
 111         /* # of queue pairs currently used by the driver */
 112         u16 curr_queue_pairs;
 113
 114         /* I like... big packets and I cannot lie! */
 115         bool big_packets;
 116
 117         /* Host will merge rx buffers for big packets (shake it! shake it!) */
 118         bool mergeable_rx_bufs;
 119
 120         /* Has control virtqueue */
 121         bool has_cvq;
 122
 123         /* Host can handle any s/g split between our header and packet data */
 124         bool any_header_sg;
 125
 126         /* Active statistics */
 127         struct virtnet_stats __percpu *stats;
 128
 129         /* Work struct for refilling if we run low on memory. */
 130         struct delayed_work refill;
 131
 132         /* Work struct for config space updates */
 133         struct work_struct config_work;
 134
 135         /* Does the affinity hint is set for virtqueues? */
 136         bool affinity_hint_set;
 137
 138         /* CPU hot plug notifier */
 139         struct notifier_block nb;
 140 };
 141
 142 struct skb_vnet_hdr {
 143         union {
 144                 struct virtio_net_hdr hdr;
 145                 struct virtio_net_hdr_mrg_rxbuf mhdr;
 146         };
 147 };
 148
 149 struct padded_vnet_hdr {
 150         struct virtio_net_hdr hdr;
 151         /*
 152          * virtio_net_hdr should be in a separated sg buffer because of a
 153          * QEMU bug, and data sg buffer shares same page with this header sg.
 154          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
 155          */
 156         char padding[6];
 157 };
 158
 159 /* Converting between virtqueue no. and kernel tx/rx queue no.
 160  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 161  */
 162 static int vq2txq(struct virtqueue *vq)
 163 {
 164         return (vq->index - 1) / 2;
 165 }
 166
 167 static int txq2vq(int txq)
 168 {
 169         return txq * 2 + 1;
 170 }
 171
 172 static int vq2rxq(struct virtqueue *vq)
 173 {
 174         return vq->index / 2;
 175 }
 176
 177 static int rxq2vq(int rxq)
 178 {
 179         return rxq * 2;
 180 }
 181
 182 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
 183 {
 184         return (struct skb_vnet_hdr *)skb->cb;
 185 }
 186
 187 /*
 188  * private is used to chain pages for big packets, put the whole
 189  * most recent used list in the beginning for reuse
 190  */
 191 static void give_pages(struct receive_queue *rq, struct page *page)
 192 {
 193         struct page *end;
 194
 195         /* Find end of list, sew whole thing into vi->rq.pages. */
 196         for (end = page; end->private; end = (struct page *)end->private);
 197         end->private = (unsigned long)rq->pages;
 198         rq->pages = page;
 199 }
 200
 201 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 202 {
 203         struct page *p = rq->pages;
 204
 205         if (p) {
 206                 rq->pages = (struct page *)p->private;
 207                 /* clear private here, it is used to chain pages */
 208                 p->private = 0;
 209         } else
 210                 p = alloc_page(gfp_mask);
 211         return p;
 212 }
 213
 214 static void skb_xmit_done(struct virtqueue *vq)
 215 {
 216         struct virtnet_info *vi = vq->vdev->priv;
 217
 218         /* Suppress further interrupts. */
 219         virtqueue_disable_cb(vq);
 220
 221         /* We were probably waiting for more output buffers. */
 222         netif_wake_subqueue(vi->dev, vq2txq(vq));
 223 }
 224
 225 static unsigned int mergeable_ctx_to_buf_truesize(unsigned long mrg_ctx)
 226 {
 227         unsigned int truesize = mrg_ctx & (MERGEABLE_BUFFER_ALIGN - 1);
 228         return (truesize + 1) * MERGEABLE_BUFFER_ALIGN;
 229 }
 230
 231 static void *mergeable_ctx_to_buf_address(unsigned long mrg_ctx)
 232 {
 233         return (void *)(mrg_ctx & -MERGEABLE_BUFFER_ALIGN);
 234
 235 }
 236
 237 static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize)
 238 {
 239         unsigned int size = truesize / MERGEABLE_BUFFER_ALIGN;
 240         return (unsigned long)buf | (size - 1);
 241 }
 242
 243 /* Called from bottom half context */
 244 static struct sk_buff *page_to_skb(struct receive_queue *rq,
 245                                    struct page *page, unsigned int offset,
 246                                    unsigned int len, unsigned int truesize)
 247 {
 248         struct virtnet_info *vi = rq->vq->vdev->priv;
 249         struct sk_buff *skb;
 250         struct skb_vnet_hdr *hdr;
 251         unsigned int copy, hdr_len, hdr_padded_len;
 252         char *p;
 253
 254         p = page_address(page) + offset;
 255
 256         /* copy small packet so we can reuse these pages for small data */
 257         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
 258         if (unlikely(!skb))
 259                 return NULL;
 260
 261         hdr = skb_vnet_hdr(skb);
 262
 263         if (vi->mergeable_rx_bufs) {
 264                 hdr_len = sizeof hdr->mhdr;
 265                 hdr_padded_len = sizeof hdr->mhdr;
 266         } else {
 267                 hdr_len = sizeof hdr->hdr;
 268                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 269         }
 270
 271         memcpy(hdr, p, hdr_len);
 272
 273         len -= hdr_len;
 274         offset += hdr_padded_len;
 275         p += hdr_padded_len;
 276
 277         copy = len;
 278         if (copy > skb_tailroom(skb))
 279                 copy = skb_tailroom(skb);
 280         memcpy(skb_put(skb, copy), p, copy);
 281
 282         len -= copy;
 283         offset += copy;
 284
 285         if (vi->mergeable_rx_bufs) {
 286                 if (len)
 287                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 288                 else
 289                         put_page(page);
 290                 return skb;
 291         }
 292
 293         /*
 294          * Verify that we can indeed put this data into a skb.
 295          * This is here to handle cases when the device erroneously
 296          * tries to receive more than is possible. This is usually
 297          * the case of a broken device.
 298          */
 299         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 300                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 301                 dev_kfree_skb(skb);
 302                 return NULL;
 303         }
 304         BUG_ON(offset >= PAGE_SIZE);
 305         while (len) {
 306                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 307                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 308                                 frag_size, truesize);
 309                 len -= frag_size;
 310                 page = (struct page *)page->private;
 311                 offset = 0;
 312         }
 313
 314         if (page)
 315                 give_pages(rq, page);
 316
 317         return skb;
 318 }
 319
 320 static struct sk_buff *receive_small(void *buf, unsigned int len)
 321 {
 322         struct sk_buff * skb = buf;
 323
 324         len -= sizeof(struct virtio_net_hdr);
 325         skb_trim(skb, len);
 326
 327         return skb;
 328 }
 329
 330 static struct sk_buff *receive_big(struct net_device *dev,
 331                                    struct receive_queue *rq,
 332                                    void *buf,
 333                                    unsigned int len)
 334 {
 335         struct page *page = buf;
 336         struct sk_buff *skb = page_to_skb(rq, page, 0, len, PAGE_SIZE);
 337
 338         if (unlikely(!skb))
 339                 goto err;
 340
 341         return skb;
 342
 343 err:
 344         dev->stats.rx_dropped++;
 345         give_pages(rq, page);
 346         return NULL;
 347 }
 348
 349 static struct sk_buff *receive_mergeable(struct net_device *dev,
 350                                          struct receive_queue *rq,
 351                                          unsigned long ctx,
 352                                          unsigned int len)
 353 {
 354         void *buf = mergeable_ctx_to_buf_address(ctx);
 355         struct skb_vnet_hdr *hdr = buf;
 356         int num_buf = hdr->mhdr.num_buffers;
 357         struct page *page = virt_to_head_page(buf);
 358         int offset = buf - page_address(page);
 359         unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 360
 361         struct sk_buff *head_skb = page_to_skb(rq, page, offset, len, truesize);
 362         struct sk_buff *curr_skb = head_skb;
 363
 364         if (unlikely(!curr_skb))
 365                 goto err_skb;
 366         while (--num_buf) {
 367                 int num_skb_frags;
 368
 369                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 370                 if (unlikely(!ctx)) {
 371                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
 372                                  dev->name, num_buf, hdr->mhdr.num_buffers);
 373                         dev->stats.rx_length_errors++;
 374                         goto err_buf;
 375                 }
 376
 377                 buf = mergeable_ctx_to_buf_address(ctx);
 378                 page = virt_to_head_page(buf);
 379
 380                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
 381                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
 382                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
 383
 384                         if (unlikely(!nskb))
 385                                 goto err_skb;
 386                         if (curr_skb == head_skb)
 387                                 skb_shinfo(curr_skb)->frag_list = nskb;
 388                         else
 389                                 curr_skb->next = nskb;
 390                         curr_skb = nskb;
 391                         head_skb->truesize += nskb->truesize;
 392                         num_skb_frags = 0;
 393                 }
 394                 truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 395                 if (curr_skb != head_skb) {
 396                         head_skb->data_len += len;
 397                         head_skb->len += len;
 398                         head_skb->truesize += truesize;
 399                 }
 400                 offset = buf - page_address(page);
 401                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
 402                         put_page(page);
 403                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
 404                                              len, truesize);
 405                 } else {
 406                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
 407                                         offset, len, truesize);
 408                 }
 409         }
 410
 411         ewma_add(&rq->mrg_avg_pkt_len, head_skb->len);
 412         return head_skb;
 413
 414 err_skb:
 415         put_page(page);
 416         while (--num_buf) {
 417                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 418                 if (unlikely(!ctx)) {
 419                         pr_debug("%s: rx error: %d buffers missing\n",
 420                                  dev->name, num_buf);
 421                         dev->stats.rx_length_errors++;
 422                         break;
 423                 }
 424                 page = virt_to_head_page(mergeable_ctx_to_buf_address(ctx));
 425                 put_page(page);
 426         }
 427 err_buf:
 428         dev->stats.rx_dropped++;
 429         dev_kfree_skb(head_skb);
 430         return NULL;
 431 }
 432
 433 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
 434 {
 435         struct virtnet_info *vi = rq->vq->vdev->priv;
 436         struct net_device *dev = vi->dev;
 437         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 438         struct sk_buff *skb;
 439         struct skb_vnet_hdr *hdr;
 440
 441         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
 442                 pr_debug("%s: short packet %i\n", dev->name, len);
 443                 dev->stats.rx_length_errors++;
 444                 if (vi->mergeable_rx_bufs) {
 445                         unsigned long ctx = (unsigned long)buf;
 446                         void *base = mergeable_ctx_to_buf_address(ctx);
 447                         put_page(virt_to_head_page(base));
 448                 } else if (vi->big_packets) {
 449                         give_pages(rq, buf);
 450                 } else {
 451                         dev_kfree_skb(buf);
 452                 }
 453                 return;
 454         }
 455
 456         if (vi->mergeable_rx_bufs)
 457                 skb = receive_mergeable(dev, rq, (unsigned long)buf, len);
 458         else if (vi->big_packets)
 459                 skb = receive_big(dev, rq, buf, len);
 460         else
 461                 skb = receive_small(buf, len);
 462
 463         if (unlikely(!skb))
 464                 return;
 465
 466         hdr = skb_vnet_hdr(skb);
 467
 468         u64_stats_update_begin(&stats->rx_syncp);
 469         stats->rx_bytes += skb->len;
 470         stats->rx_packets++;
 471         u64_stats_update_end(&stats->rx_syncp);
 472
 473         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 474                 pr_debug("Needs csum!\n");
 475                 if (!skb_partial_csum_set(skb,
 476                                           hdr->hdr.csum_start,
 477                                           hdr->hdr.csum_offset))
 478                         goto frame_err;
 479         } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
 480                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 481         }
 482
 483         skb->protocol = eth_type_trans(skb, dev);
 484         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 485                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 486
 487         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 488                 pr_debug("GSO!\n");
 489                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 490                 case VIRTIO_NET_HDR_GSO_TCPV4:
 491                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 492                         break;
 493                 case VIRTIO_NET_HDR_GSO_UDP:
 494                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 495                         break;
 496                 case VIRTIO_NET_HDR_GSO_TCPV6:
 497                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 498                         break;
 499                 default:
 500                         net_warn_ratelimited("%s: bad gso type %u.\n",
 501                                              dev->name, hdr->hdr.gso_type);
 502                         goto frame_err;
 503                 }
 504
 505                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 506                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 507
 508                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
 509                 if (skb_shinfo(skb)->gso_size == 0) {
 510                         net_warn_ratelimited("%s: zero gso size.\n", dev->name);
 511                         goto frame_err;
 512                 }
 513
 514                 /* Header must be checked, and gso_segs computed. */
 515                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 516                 skb_shinfo(skb)->gso_segs = 0;
 517         }
 518
 519         skb_mark_napi_id(skb, &rq->napi);
 520
 521         netif_receive_skb(skb);
 522         return;
 523
 524 frame_err:
 525         dev->stats.rx_frame_errors++;
 526         dev_kfree_skb(skb);
 527 }
 528
 529 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
 530 {
 531         struct virtnet_info *vi = rq->vq->vdev->priv;
 532         struct sk_buff *skb;
 533         struct skb_vnet_hdr *hdr;
 534         int err;
 535
 536         skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
 537         if (unlikely(!skb))
 538                 return -ENOMEM;
 539
 540         skb_put(skb, GOOD_PACKET_LEN);
 541
 542         hdr = skb_vnet_hdr(skb);
 543         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
 544         sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
 545         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 546
 547         err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
 548         if (err < 0)
 549                 dev_kfree_skb(skb);
 550
 551         return err;
 552 }
 553
 554 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
 555 {
 556         struct page *first, *list = NULL;
 557         char *p;
 558         int i, err, offset;
 559
 560         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
 561
 562         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 563         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 564                 first = get_a_page(rq, gfp);
 565                 if (!first) {
 566                         if (list)
 567                                 give_pages(rq, list);
 568                         return -ENOMEM;
 569                 }
 570                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
 571
 572                 /* chain new page in list head to match sg */
 573                 first->private = (unsigned long)list;
 574                 list = first;
 575         }
 576
 577         first = get_a_page(rq, gfp);
 578         if (!first) {
 579                 give_pages(rq, list);
 580                 return -ENOMEM;
 581         }
 582         p = page_address(first);
 583
 584         /* rq->sg[0], rq->sg[1] share the same page */
 585         /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
 586         sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
 587
 588         /* rq->sg[1] for data packet, from offset */
 589         offset = sizeof(struct padded_vnet_hdr);
 590         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
 591
 592         /* chain first in list head */
 593         first->private = (unsigned long)list;
 594         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
 595                                   first, gfp);
 596         if (err < 0)
 597                 give_pages(rq, first);
 598
 599         return err;
 600 }
 601
 602 static unsigned int get_mergeable_buf_len(struct ewma *avg_pkt_len)
 603 {
 604         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 605         unsigned int len;
 606
 607         len = hdr_len + clamp_t(unsigned int, ewma_read(avg_pkt_len),
 608                         GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
 609         return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
 610 }
 611
 612 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
 613 {
 614         struct page_frag *alloc_frag = &rq->alloc_frag;
 615         char *buf;
 616         unsigned long ctx;
 617         int err;
 618         unsigned int len, hole;
 619
 620         len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
 621         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
 622                 return -ENOMEM;
 623
 624         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
 625         ctx = mergeable_buf_to_ctx(buf, len);
 626         get_page(alloc_frag->page);
 627         alloc_frag->offset += len;
 628         hole = alloc_frag->size - alloc_frag->offset;
 629         if (hole < len) {
 630                 /* To avoid internal fragmentation, if there is very likely not
 631                  * enough space for another buffer, add the remaining space to
 632                  * the current buffer. This extra space is not included in
 633                  * the truesize stored in ctx.
 634                  */
 635                 len += hole;
 636                 alloc_frag->offset += hole;
 637         }
 638
 639         sg_init_one(rq->sg, buf, len);
 640         err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
 641         if (err < 0)
 642                 put_page(virt_to_head_page(buf));
 643
 644         return err;
 645 }
 646
 647 /*
 648  * Returns false if we couldn't fill entirely (OOM).
 649  *
 650  * Normally run in the receive path, but can also be run from ndo_open
 651  * before we're receiving packets, or from refill_work which is
 652  * careful to disable receiving (using napi_disable).
 653  */
 654 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
 655 {
 656         struct virtnet_info *vi = rq->vq->vdev->priv;
 657         int err;
 658         bool oom;
 659
 660         gfp |= __GFP_COLD;
 661         do {
 662                 if (vi->mergeable_rx_bufs)
 663                         err = add_recvbuf_mergeable(rq, gfp);
 664                 else if (vi->big_packets)
 665                         err = add_recvbuf_big(rq, gfp);
 666                 else
 667                         err = add_recvbuf_small(rq, gfp);
 668
 669                 oom = err == -ENOMEM;
 670                 if (err)
 671                         break;
 672         } while (rq->vq->num_free);
 673         virtqueue_kick(rq->vq);
 674         return !oom;
 675 }
 676
 677 static void skb_recv_done(struct virtqueue *rvq)
 678 {
 679         struct virtnet_info *vi = rvq->vdev->priv;
 680         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 681
 682         /* Schedule NAPI, Suppress further interrupts if successful. */
 683         if (napi_schedule_prep(&rq->napi)) {
 684                 virtqueue_disable_cb(rvq);
 685                 __napi_schedule(&rq->napi);
 686         }
 687 }
 688
 689 static void virtnet_napi_enable(struct receive_queue *rq)
 690 {
 691         napi_enable(&rq->napi);
 692
 693         /* If all buffers were filled by other side before we napi_enabled, we
 694          * won't get another interrupt, so process any outstanding packets
 695          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 696          * We synchronize against interrupts via NAPI_STATE_SCHED */
 697         if (napi_schedule_prep(&rq->napi)) {
 698                 virtqueue_disable_cb(rq->vq);
 699                 local_bh_disable();
 700                 __napi_schedule(&rq->napi);
 701                 local_bh_enable();
 702         }
 703 }
 704
 705 static void refill_work(struct work_struct *work)
 706 {
 707         struct virtnet_info *vi =
 708                 container_of(work, struct virtnet_info, refill.work);
 709         bool still_empty;
 710         int i;
 711
 712         for (i = 0; i < vi->curr_queue_pairs; i++) {
 713                 struct receive_queue *rq = &vi->rq[i];
 714
 715                 napi_disable(&rq->napi);
 716                 still_empty = !try_fill_recv(rq, GFP_KERNEL);
 717                 virtnet_napi_enable(rq);
 718
 719                 /* In theory, this can happen: if we don't get any buffers in
 720                  * we will *never* try to fill again.
 721                  */
 722                 if (still_empty)
 723                         schedule_delayed_work(&vi->refill, HZ/2);
 724         }
 725 }
 726
 727 static int virtnet_receive(struct receive_queue *rq, int budget)
 728 {
 729         struct virtnet_info *vi = rq->vq->vdev->priv;
 730         unsigned int len, received = 0;
 731         void *buf;
 732
 733         while (received < budget &&
 734                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
 735                 receive_buf(rq, buf, len);
 736                 received++;
 737         }
 738
 739         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
 740                 if (!try_fill_recv(rq, GFP_ATOMIC))
 741                         schedule_delayed_work(&vi->refill, 0);
 742         }
 743
 744         return received;
 745 }
 746
 747 static int virtnet_poll(struct napi_struct *napi, int budget)
 748 {
 749         struct receive_queue *rq =
 750                 container_of(napi, struct receive_queue, napi);
 751         unsigned int r, received = 0;
 752
 753 again:
 754         received += virtnet_receive(rq, budget - received);
 755
 756         /* Out of packets? */
 757         if (received < budget) {
 758                 r = virtqueue_enable_cb_prepare(rq->vq);
 759                 napi_complete(napi);
 760                 if (unlikely(virtqueue_poll(rq->vq, r)) &&
 761                     napi_schedule_prep(napi)) {
 762                         virtqueue_disable_cb(rq->vq);
 763                         __napi_schedule(napi);
 764                         goto again;
 765                 }
 766         }
 767
 768         return received;
 769 }
 770
 771 #ifdef CONFIG_NET_RX_BUSY_POLL
 772 /* must be called with local_bh_disable()d */
 773 static int virtnet_busy_poll(struct napi_struct *napi)
 774 {
 775         struct receive_queue *rq =
 776                 container_of(napi, struct receive_queue, napi);
 777         struct virtnet_info *vi = rq->vq->vdev->priv;
 778         int r, received = 0, budget = 4;
 779
 780         if (!(vi->status & VIRTIO_NET_S_LINK_UP))
 781                 return LL_FLUSH_FAILED;
 782
 783         if (!napi_schedule_prep(napi))
 784                 return LL_FLUSH_BUSY;
 785
 786         virtqueue_disable_cb(rq->vq);
 787
 788 again:
 789         received += virtnet_receive(rq, budget);
 790
 791         r = virtqueue_enable_cb_prepare(rq->vq);
 792         clear_bit(NAPI_STATE_SCHED, &napi->state);
 793         if (unlikely(virtqueue_poll(rq->vq, r)) &&
 794             napi_schedule_prep(napi)) {
 795                 virtqueue_disable_cb(rq->vq);
 796                 if (received < budget) {
 797                         budget -= received;
 798                         goto again;
 799                 } else {
 800                         __napi_schedule(napi);
 801                 }
 802         }
 803
 804         return received;
 805 }
 806 #endif  /* CONFIG_NET_RX_BUSY_POLL */
 807
 808 static int virtnet_open(struct net_device *dev)
 809 {
 810         struct virtnet_info *vi = netdev_priv(dev);
 811         int i;
 812
 813         for (i = 0; i < vi->max_queue_pairs; i++) {
 814                 if (i < vi->curr_queue_pairs)
 815                         /* Make sure we have some buffers: if oom use wq. */
 816                         if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
 817                                 schedule_delayed_work(&vi->refill, 0);
 818                 virtnet_napi_enable(&vi->rq[i]);
 819         }
 820
 821         return 0;
 822 }
 823
 824 static void free_old_xmit_skbs(struct send_queue *sq)
 825 {
 826         struct sk_buff *skb;
 827         unsigned int len;
 828         struct virtnet_info *vi = sq->vq->vdev->priv;
 829         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 830
 831         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 832                 pr_debug("Sent skb %p\n", skb);
 833
 834                 u64_stats_update_begin(&stats->tx_syncp);
 835                 stats->tx_bytes += skb->len;
 836                 stats->tx_packets++;
 837                 u64_stats_update_end(&stats->tx_syncp);
 838
 839                 dev_kfree_skb_any(skb);
 840         }
 841 }
 842
 843 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 844 {
 845         struct skb_vnet_hdr *hdr;
 846         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 847         struct virtnet_info *vi = sq->vq->vdev->priv;
 848         unsigned num_sg;
 849         unsigned hdr_len;
 850         bool can_push;
 851
 852         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 853         if (vi->mergeable_rx_bufs)
 854                 hdr_len = sizeof hdr->mhdr;
 855         else
 856                 hdr_len = sizeof hdr->hdr;
 857
 858         can_push = vi->any_header_sg &&
 859                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
 860                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
 861         /* Even if we can, don't push here yet as this would skew
 862          * csum_start offset below. */
 863         if (can_push)
 864                 hdr = (struct skb_vnet_hdr *)(skb->data - hdr_len);
 865         else
 866                 hdr = skb_vnet_hdr(skb);
 867
 868         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 869                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 870                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
 871                 hdr->hdr.csum_offset = skb->csum_offset;
 872         } else {
 873                 hdr->hdr.flags = 0;
 874                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 875         }
 876
 877         if (skb_is_gso(skb)) {
 878                 hdr->hdr.hdr_len = skb_headlen(skb);
 879                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
 880                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 881                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 882                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 883                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 884                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 885                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 886                 else
 887                         BUG();
 888                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 889                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 890         } else {
 891                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 892                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
 893         }
 894
 895         if (vi->mergeable_rx_bufs)
 896                 hdr->mhdr.num_buffers = 0;
 897
 898         sg_init_table(sq->sg, MAX_SKB_FRAGS + 2);
 899         if (can_push) {
 900                 __skb_push(skb, hdr_len);
 901                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
 902                 /* Pull header back to avoid skew in tx bytes calculations. */
 903                 __skb_pull(skb, hdr_len);
 904         } else {
 905                 sg_set_buf(sq->sg, hdr, hdr_len);
 906                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
 907         }
 908         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
 909 }
 910
 911 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 912 {
 913         struct virtnet_info *vi = netdev_priv(dev);
 914         int qnum = skb_get_queue_mapping(skb);
 915         struct send_queue *sq = &vi->sq[qnum];
 916         int err;
 917         struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
 918         bool kick = !skb->xmit_more;
 919
 920         /* Free up any pending old buffers before queueing new ones. */
 921         free_old_xmit_skbs(sq);
 922
 923         /* Try to transmit */
 924         err = xmit_skb(sq, skb);
 925
 926         /* This should not happen! */
 927         if (unlikely(err)) {
 928                 dev->stats.tx_fifo_errors++;
 929                 if (net_ratelimit())
 930                         dev_warn(&dev->dev,
 931                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
 932                 dev->stats.tx_dropped++;
 933                 dev_kfree_skb_any(skb);
 934                 return NETDEV_TX_OK;
 935         }
 936
 937         /* Don't wait up for transmitted skbs to be freed. */
 938         skb_orphan(skb);
 939         nf_reset(skb);
 940
 941         /* Apparently nice girls don't return TX_BUSY; stop the queue
 942          * before it gets out of hand.  Naturally, this wastes entries. */
 943         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
 944                 netif_stop_subqueue(dev, qnum);
 945                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 946                         /* More just got used, free them then recheck. */
 947                         free_old_xmit_skbs(sq);
 948                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
 949                                 netif_start_subqueue(dev, qnum);
 950                                 virtqueue_disable_cb(sq->vq);
 951                         }
 952                 }
 953         }
 954
 955         if (kick || netif_xmit_stopped(txq))
 956                 virtqueue_kick(sq->vq);
 957
 958         return NETDEV_TX_OK;
 959 }
 960
 961 /*
 962  * Send command via the control virtqueue and check status.  Commands
 963  * supported by the hypervisor, as indicated by feature bits, should
 964  * never fail unless improperly formatted.
 965  */
 966 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 967                                  struct scatterlist *out)
 968 {
 969         struct scatterlist *sgs[4], hdr, stat;
 970         struct virtio_net_ctrl_hdr ctrl;
 971         virtio_net_ctrl_ack status = ~0;
 972         unsigned out_num = 0, tmp;
 973
 974         /* Caller should know better */
 975         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
 976
 977         ctrl.class = class;
 978         ctrl.cmd = cmd;
 979         /* Add header */
 980         sg_init_one(&hdr, &ctrl, sizeof(ctrl));
 981         sgs[out_num++] = &hdr;
 982
 983         if (out)
 984                 sgs[out_num++] = out;
 985
 986         /* Add return status. */
 987         sg_init_one(&stat, &status, sizeof(status));
 988         sgs[out_num] = &stat;
 989
 990         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
 991         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
 992
 993         if (unlikely(!virtqueue_kick(vi->cvq)))
 994                 return status == VIRTIO_NET_OK;
 995
 996         /* Spin for a response, the kick causes an ioport write, trapping
 997          * into the hypervisor, so the request should be handled immediately.
 998          */
 999         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1000                !virtqueue_is_broken(vi->cvq))
1001                 cpu_relax();
1002
1003         return status == VIRTIO_NET_OK;
1004 }
1005
1006 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1007 {
1008         struct virtnet_info *vi = netdev_priv(dev);
1009         struct virtio_device *vdev = vi->vdev;
1010         int ret;
1011         struct sockaddr *addr = p;
1012         struct scatterlist sg;
1013
1014         ret = eth_prepare_mac_addr_change(dev, p);
1015         if (ret)
1016                 return ret;
1017
1018         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1019                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1020                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1021                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1022                         dev_warn(&vdev->dev,
1023                                  "Failed to set mac address by vq command.\n");
1024                         return -EINVAL;
1025                 }
1026         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
1027                 unsigned int i;
1028
1029                 /* Naturally, this has an atomicity problem. */
1030                 for (i = 0; i < dev->addr_len; i++)
1031                         virtio_cwrite8(vdev,
1032                                        offsetof(struct virtio_net_config, mac) +
1033                                        i, addr->sa_data[i]);
1034         }
1035
1036         eth_commit_mac_addr_change(dev, p);
1037
1038         return 0;
1039 }
1040
1041 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
1042                                                struct rtnl_link_stats64 *tot)
1043 {
1044         struct virtnet_info *vi = netdev_priv(dev);
1045         int cpu;
1046         unsigned int start;
1047
1048         for_each_possible_cpu(cpu) {
1049                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1050                 u64 tpackets, tbytes, rpackets, rbytes;
1051
1052                 do {
1053                         start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
1054                         tpackets = stats->tx_packets;
1055                         tbytes   = stats->tx_bytes;
1056                 } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
1057
1058                 do {
1059                         start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
1060                         rpackets = stats->rx_packets;
1061                         rbytes   = stats->rx_bytes;
1062                 } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
1063
1064                 tot->rx_packets += rpackets;
1065                 tot->tx_packets += tpackets;
1066                 tot->rx_bytes   += rbytes;
1067                 tot->tx_bytes   += tbytes;
1068         }
1069
1070         tot->tx_dropped = dev->stats.tx_dropped;
1071         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1072         tot->rx_dropped = dev->stats.rx_dropped;
1073         tot->rx_length_errors = dev->stats.rx_length_errors;
1074         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1075
1076         return tot;
1077 }
1078
1079 #ifdef CONFIG_NET_POLL_CONTROLLER
1080 static void virtnet_netpoll(struct net_device *dev)
1081 {
1082         struct virtnet_info *vi = netdev_priv(dev);
1083         int i;
1084
1085         for (i = 0; i < vi->curr_queue_pairs; i++)
1086                 napi_schedule(&vi->rq[i].napi);
1087 }
1088 #endif
1089
1090 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1091 {
1092         rtnl_lock();
1093         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1094                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1095                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1096         rtnl_unlock();
1097 }
1098
1099 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1100 {
1101         struct scatterlist sg;
1102         struct virtio_net_ctrl_mq s;
1103         struct net_device *dev = vi->dev;
1104
1105         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1106                 return 0;
1107
1108         s.virtqueue_pairs = queue_pairs;
1109         sg_init_one(&sg, &s, sizeof(s));
1110
1111         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1112                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1113                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1114                          queue_pairs);
1115                 return -EINVAL;
1116         } else {
1117                 vi->curr_queue_pairs = queue_pairs;
1118                 /* virtnet_open() will refill when device is going to up. */
1119                 if (dev->flags & IFF_UP)
1120                         schedule_delayed_work(&vi->refill, 0);
1121         }
1122
1123         return 0;
1124 }
1125
1126 static int virtnet_close(struct net_device *dev)
1127 {
1128         struct virtnet_info *vi = netdev_priv(dev);
1129         int i;
1130
1131         /* Make sure refill_work doesn't re-enable napi! */
1132         cancel_delayed_work_sync(&vi->refill);
1133
1134         for (i = 0; i < vi->max_queue_pairs; i++)
1135                 napi_disable(&vi->rq[i].napi);
1136
1137         return 0;
1138 }
1139
1140 static void virtnet_set_rx_mode(struct net_device *dev)
1141 {
1142         struct virtnet_info *vi = netdev_priv(dev);
1143         struct scatterlist sg[2];
1144         u8 promisc, allmulti;
1145         struct virtio_net_ctrl_mac *mac_data;
1146         struct netdev_hw_addr *ha;
1147         int uc_count;
1148         int mc_count;
1149         void *buf;
1150         int i;
1151
1152         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1153         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1154                 return;
1155
1156         promisc = ((dev->flags & IFF_PROMISC) != 0);
1157         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1158
1159         sg_init_one(sg, &promisc, sizeof(promisc));
1160
1161         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1162                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1163                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1164                          promisc ? "en" : "dis");
1165
1166         sg_init_one(sg, &allmulti, sizeof(allmulti));
1167
1168         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1169                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1170                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1171                          allmulti ? "en" : "dis");
1172
1173         uc_count = netdev_uc_count(dev);
1174         mc_count = netdev_mc_count(dev);
1175         /* MAC filter - use one buffer for both lists */
1176         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1177                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1178         mac_data = buf;
1179         if (!buf)
1180                 return;
1181
1182         sg_init_table(sg, 2);
1183
1184         /* Store the unicast list and count in the front of the buffer */
1185         mac_data->entries = uc_count;
1186         i = 0;
1187         netdev_for_each_uc_addr(ha, dev)
1188                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1189
1190         sg_set_buf(&sg[0], mac_data,
1191                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1192
1193         /* multicast list and count fill the end */
1194         mac_data = (void *)&mac_data->macs[uc_count][0];
1195
1196         mac_data->entries = mc_count;
1197         i = 0;
1198         netdev_for_each_mc_addr(ha, dev)
1199                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1200
1201         sg_set_buf(&sg[1], mac_data,
1202                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1203
1204         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1205                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1206                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1207
1208         kfree(buf);
1209 }
1210
1211 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1212                                    __be16 proto, u16 vid)
1213 {
1214         struct virtnet_info *vi = netdev_priv(dev);
1215         struct scatterlist sg;
1216
1217         sg_init_one(&sg, &vid, sizeof(vid));
1218
1219         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1220                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1221                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1222         return 0;
1223 }
1224
1225 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1226                                     __be16 proto, u16 vid)
1227 {
1228         struct virtnet_info *vi = netdev_priv(dev);
1229         struct scatterlist sg;
1230
1231         sg_init_one(&sg, &vid, sizeof(vid));
1232
1233         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1234                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1235                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1236         return 0;
1237 }
1238
1239 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1240 {
1241         int i;
1242
1243         if (vi->affinity_hint_set) {
1244                 for (i = 0; i < vi->max_queue_pairs; i++) {
1245                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1246                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1247                 }
1248
1249                 vi->affinity_hint_set = false;
1250         }
1251 }
1252
1253 static void virtnet_set_affinity(struct virtnet_info *vi)
1254 {
1255         int i;
1256         int cpu;
1257
1258         /* In multiqueue mode, when the number of cpu is equal to the number of
1259          * queue pairs, we let the queue pairs to be private to one cpu by
1260          * setting the affinity hint to eliminate the contention.
1261          */
1262         if (vi->curr_queue_pairs == 1 ||
1263             vi->max_queue_pairs != num_online_cpus()) {
1264                 virtnet_clean_affinity(vi, -1);
1265                 return;
1266         }
1267
1268         i = 0;
1269         for_each_online_cpu(cpu) {
1270                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1271                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1272                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1273                 i++;
1274         }
1275
1276         vi->affinity_hint_set = true;
1277 }
1278
1279 static int virtnet_cpu_callback(struct notifier_block *nfb,
1280                                 unsigned long action, void *hcpu)
1281 {
1282         struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);
1283
1284         switch(action & ~CPU_TASKS_FROZEN) {
1285         case CPU_ONLINE:
1286         case CPU_DOWN_FAILED:
1287         case CPU_DEAD:
1288                 virtnet_set_affinity(vi);
1289                 break;
1290         case CPU_DOWN_PREPARE:
1291                 virtnet_clean_affinity(vi, (long)hcpu);
1292                 break;
1293         default:
1294                 break;
1295         }
1296
1297         return NOTIFY_OK;
1298 }
1299
1300 static void virtnet_get_ringparam(struct net_device *dev,
1301                                 struct ethtool_ringparam *ring)
1302 {
1303         struct virtnet_info *vi = netdev_priv(dev);
1304
1305         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1306         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1307         ring->rx_pending = ring->rx_max_pending;
1308         ring->tx_pending = ring->tx_max_pending;
1309 }
1310
1311
1312 static void virtnet_get_drvinfo(struct net_device *dev,
1313                                 struct ethtool_drvinfo *info)
1314 {
1315         struct virtnet_info *vi = netdev_priv(dev);
1316         struct virtio_device *vdev = vi->vdev;
1317
1318         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1319         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1320         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1321
1322 }
1323
1324 /* TODO: Eliminate OOO packets during switching */
1325 static int virtnet_set_channels(struct net_device *dev,
1326                                 struct ethtool_channels *channels)
1327 {
1328         struct virtnet_info *vi = netdev_priv(dev);
1329         u16 queue_pairs = channels->combined_count;
1330         int err;
1331
1332         /* We don't support separate rx/tx channels.
1333          * We don't allow setting 'other' channels.
1334          */
1335         if (channels->rx_count || channels->tx_count || channels->other_count)
1336                 return -EINVAL;
1337
1338         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1339                 return -EINVAL;
1340
1341         get_online_cpus();
1342         err = virtnet_set_queues(vi, queue_pairs);
1343         if (!err) {
1344                 netif_set_real_num_tx_queues(dev, queue_pairs);
1345                 netif_set_real_num_rx_queues(dev, queue_pairs);
1346
1347                 virtnet_set_affinity(vi);
1348         }
1349         put_online_cpus();
1350
1351         return err;
1352 }
1353
1354 static void virtnet_get_channels(struct net_device *dev,
1355                                  struct ethtool_channels *channels)
1356 {
1357         struct virtnet_info *vi = netdev_priv(dev);
1358
1359         channels->combined_count = vi->curr_queue_pairs;
1360         channels->max_combined = vi->max_queue_pairs;
1361         channels->max_other = 0;
1362         channels->rx_count = 0;
1363         channels->tx_count = 0;
1364         channels->other_count = 0;
1365 }
1366
1367 static const struct ethtool_ops virtnet_ethtool_ops = {
1368         .get_drvinfo = virtnet_get_drvinfo,
1369         .get_link = ethtool_op_get_link,
1370         .get_ringparam = virtnet_get_ringparam,
1371         .set_channels = virtnet_set_channels,
1372         .get_channels = virtnet_get_channels,
1373 };
1374
1375 #define MIN_MTU 68
1376 #define MAX_MTU 65535
1377
1378 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1379 {
1380         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1381                 return -EINVAL;
1382         dev->mtu = new_mtu;
1383         return 0;
1384 }
1385
1386 static const struct net_device_ops virtnet_netdev = {
1387         .ndo_open            = virtnet_open,
1388         .ndo_stop            = virtnet_close,
1389         .ndo_start_xmit      = start_xmit,
1390         .ndo_validate_addr   = eth_validate_addr,
1391         .ndo_set_mac_address = virtnet_set_mac_address,
1392         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1393         .ndo_change_mtu      = virtnet_change_mtu,
1394         .ndo_get_stats64     = virtnet_stats,
1395         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1396         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1397 #ifdef CONFIG_NET_POLL_CONTROLLER
1398         .ndo_poll_controller = virtnet_netpoll,
1399 #endif
1400 #ifdef CONFIG_NET_RX_BUSY_POLL
1401         .ndo_busy_poll          = virtnet_busy_poll,
1402 #endif
1403 };
1404
1405 static void virtnet_config_changed_work(struct work_struct *work)
1406 {
1407         struct virtnet_info *vi =
1408                 container_of(work, struct virtnet_info, config_work);
1409         u16 v;
1410
1411         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
1412                                  struct virtio_net_config, status, &v) < 0)
1413                 return;
1414
1415         if (v & VIRTIO_NET_S_ANNOUNCE) {
1416                 netdev_notify_peers(vi->dev);
1417                 virtnet_ack_link_announce(vi);
1418         }
1419
1420         /* Ignore unknown (future) status bits */
1421         v &= VIRTIO_NET_S_LINK_UP;
1422
1423         if (vi->status == v)
1424                 return;
1425
1426         vi->status = v;
1427
1428         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1429                 netif_carrier_on(vi->dev);
1430                 netif_tx_wake_all_queues(vi->dev);
1431         } else {
1432                 netif_carrier_off(vi->dev);
1433                 netif_tx_stop_all_queues(vi->dev);
1434         }
1435 }
1436
1437 static void virtnet_config_changed(struct virtio_device *vdev)
1438 {
1439         struct virtnet_info *vi = vdev->priv;
1440
1441         schedule_work(&vi->config_work);
1442 }
1443
1444 static void virtnet_free_queues(struct virtnet_info *vi)
1445 {
1446         int i;
1447
1448         for (i = 0; i < vi->max_queue_pairs; i++)
1449                 netif_napi_del(&vi->rq[i].napi);
1450
1451         kfree(vi->rq);
1452         kfree(vi->sq);
1453 }
1454
1455 static void free_receive_bufs(struct virtnet_info *vi)
1456 {
1457         int i;
1458
1459         for (i = 0; i < vi->max_queue_pairs; i++) {
1460                 while (vi->rq[i].pages)
1461                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1462         }
1463 }
1464
1465 static void free_receive_page_frags(struct virtnet_info *vi)
1466 {
1467         int i;
1468         for (i = 0; i < vi->max_queue_pairs; i++)
1469                 if (vi->rq[i].alloc_frag.page)
1470                         put_page(vi->rq[i].alloc_frag.page);
1471 }
1472
1473 static void free_unused_bufs(struct virtnet_info *vi)
1474 {
1475         void *buf;
1476         int i;
1477
1478         for (i = 0; i < vi->max_queue_pairs; i++) {
1479                 struct virtqueue *vq = vi->sq[i].vq;
1480                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1481                         dev_kfree_skb(buf);
1482         }
1483
1484         for (i = 0; i < vi->max_queue_pairs; i++) {
1485                 struct virtqueue *vq = vi->rq[i].vq;
1486
1487                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1488                         if (vi->mergeable_rx_bufs) {
1489                                 unsigned long ctx = (unsigned long)buf;
1490                                 void *base = mergeable_ctx_to_buf_address(ctx);
1491                                 put_page(virt_to_head_page(base));
1492                         } else if (vi->big_packets) {
1493                                 give_pages(&vi->rq[i], buf);
1494                         } else {
1495                                 dev_kfree_skb(buf);
1496                         }
1497                 }
1498         }
1499 }
1500
1501 static void virtnet_del_vqs(struct virtnet_info *vi)
1502 {
1503         struct virtio_device *vdev = vi->vdev;
1504
1505         virtnet_clean_affinity(vi, -1);
1506
1507         vdev->config->del_vqs(vdev);
1508
1509         virtnet_free_queues(vi);
1510 }
1511
1512 static int virtnet_find_vqs(struct virtnet_info *vi)
1513 {
1514         vq_callback_t **callbacks;
1515         struct virtqueue **vqs;
1516         int ret = -ENOMEM;
1517         int i, total_vqs;
1518         const char **names;
1519
1520         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1521          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1522          * possible control vq.
1523          */
1524         total_vqs = vi->max_queue_pairs * 2 +
1525                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1526
1527         /* Allocate space for find_vqs parameters */
1528         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1529         if (!vqs)
1530                 goto err_vq;
1531         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1532         if (!callbacks)
1533                 goto err_callback;
1534         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1535         if (!names)
1536                 goto err_names;
1537
1538         /* Parameters for control virtqueue, if any */
1539         if (vi->has_cvq) {
1540                 callbacks[total_vqs - 1] = NULL;
1541                 names[total_vqs - 1] = "control";
1542         }
1543
1544         /* Allocate/initialize parameters for send/receive virtqueues */
1545         for (i = 0; i < vi->max_queue_pairs; i++) {
1546                 callbacks[rxq2vq(i)] = skb_recv_done;
1547                 callbacks[txq2vq(i)] = skb_xmit_done;
1548                 sprintf(vi->rq[i].name, "input.%d", i);
1549                 sprintf(vi->sq[i].name, "output.%d", i);
1550                 names[rxq2vq(i)] = vi->rq[i].name;
1551                 names[txq2vq(i)] = vi->sq[i].name;
1552         }
1553
1554         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1555                                          names);
1556         if (ret)
1557                 goto err_find;
1558
1559         if (vi->has_cvq) {
1560                 vi->cvq = vqs[total_vqs - 1];
1561                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1562                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1563         }
1564
1565         for (i = 0; i < vi->max_queue_pairs; i++) {
1566                 vi->rq[i].vq = vqs[rxq2vq(i)];
1567                 vi->sq[i].vq = vqs[txq2vq(i)];
1568         }
1569
1570         kfree(names);
1571         kfree(callbacks);
1572         kfree(vqs);
1573
1574         return 0;
1575
1576 err_find:
1577         kfree(names);
1578 err_names:
1579         kfree(callbacks);
1580 err_callback:
1581         kfree(vqs);
1582 err_vq:
1583         return ret;
1584 }
1585
1586 static int virtnet_alloc_queues(struct virtnet_info *vi)
1587 {
1588         int i;
1589
1590         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1591         if (!vi->sq)
1592                 goto err_sq;
1593         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1594         if (!vi->rq)
1595                 goto err_rq;
1596
1597         INIT_DELAYED_WORK(&vi->refill, refill_work);
1598         for (i = 0; i < vi->max_queue_pairs; i++) {
1599                 vi->rq[i].pages = NULL;
1600                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1601                                napi_weight);
1602                 napi_hash_add(&vi->rq[i].napi);
1603
1604                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1605                 ewma_init(&vi->rq[i].mrg_avg_pkt_len, 1, RECEIVE_AVG_WEIGHT);
1606                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1607         }
1608
1609         return 0;
1610
1611 err_rq:
1612         kfree(vi->sq);
1613 err_sq:
1614         return -ENOMEM;
1615 }
1616
1617 static int init_vqs(struct virtnet_info *vi)
1618 {
1619         int ret;
1620
1621         /* Allocate send & receive queues */
1622         ret = virtnet_alloc_queues(vi);
1623         if (ret)
1624                 goto err;
1625
1626         ret = virtnet_find_vqs(vi);
1627         if (ret)
1628                 goto err_free;
1629
1630         get_online_cpus();
1631         virtnet_set_affinity(vi);
1632         put_online_cpus();
1633
1634         return 0;
1635
1636 err_free:
1637         virtnet_free_queues(vi);
1638 err:
1639         return ret;
1640 }
1641
1642 #ifdef CONFIG_SYSFS
1643 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
1644                 struct rx_queue_attribute *attribute, char *buf)
1645 {
1646         struct virtnet_info *vi = netdev_priv(queue->dev);
1647         unsigned int queue_index = get_netdev_rx_queue_index(queue);
1648         struct ewma *avg;
1649
1650         BUG_ON(queue_index >= vi->max_queue_pairs);
1651         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
1652         return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
1653 }
1654
1655 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
1656         __ATTR_RO(mergeable_rx_buffer_size);
1657
1658 static struct attribute *virtio_net_mrg_rx_attrs[] = {
1659         &mergeable_rx_buffer_size_attribute.attr,
1660         NULL
1661 };
1662
1663 static const struct attribute_group virtio_net_mrg_rx_group = {
1664         .name = "virtio_net",
1665         .attrs = virtio_net_mrg_rx_attrs
1666 };
1667 #endif
1668
1669 static int virtnet_probe(struct virtio_device *vdev)
1670 {
1671         int i, err;
1672         struct net_device *dev;
1673         struct virtnet_info *vi;
1674         u16 max_queue_pairs;
1675
1676         /* Find if host supports multiqueue virtio_net device */
1677         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
1678                                    struct virtio_net_config,
1679                                    max_virtqueue_pairs, &max_queue_pairs);
1680
1681         /* We need at least 2 queue's */
1682         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1683             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1684             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1685                 max_queue_pairs = 1;
1686
1687         /* Allocate ourselves a network device with room for our info */
1688         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1689         if (!dev)
1690                 return -ENOMEM;
1691
1692         /* Set up network device as normal. */
1693         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1694         dev->netdev_ops = &virtnet_netdev;
1695         dev->features = NETIF_F_HIGHDMA;
1696
1697         dev->ethtool_ops = &virtnet_ethtool_ops;
1698         SET_NETDEV_DEV(dev, &vdev->dev);
1699
1700         /* Do we support "hardware" checksums? */
1701         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1702                 /* This opens up the world of extra features. */
1703                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1704                 if (csum)
1705                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1706
1707                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1708                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1709                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1710                 }
1711                 /* Individual feature bits: what can host handle? */
1712                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1713                         dev->hw_features |= NETIF_F_TSO;
1714                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1715                         dev->hw_features |= NETIF_F_TSO6;
1716                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1717                         dev->hw_features |= NETIF_F_TSO_ECN;
1718                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1719                         dev->hw_features |= NETIF_F_UFO;
1720
1721                 if (gso)
1722                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1723                 /* (!csum && gso) case will be fixed by register_netdev() */
1724         }
1725         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
1726                 dev->features |= NETIF_F_RXCSUM;
1727
1728         dev->vlan_features = dev->features;
1729
1730         /* Configuration may specify what MAC to use.  Otherwise random. */
1731         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
1732                 virtio_cread_bytes(vdev,
1733                                    offsetof(struct virtio_net_config, mac),
1734                                    dev->dev_addr, dev->addr_len);
1735         else
1736                 eth_hw_addr_random(dev);
1737
1738         /* Set up our device-specific information */
1739         vi = netdev_priv(dev);
1740         vi->dev = dev;
1741         vi->vdev = vdev;
1742         vdev->priv = vi;
1743         vi->stats = alloc_percpu(struct virtnet_stats);
1744         err = -ENOMEM;
1745         if (vi->stats == NULL)
1746                 goto free;
1747
1748         for_each_possible_cpu(i) {
1749                 struct virtnet_stats *virtnet_stats;
1750                 virtnet_stats = per_cpu_ptr(vi->stats, i);
1751                 u64_stats_init(&virtnet_stats->tx_syncp);
1752                 u64_stats_init(&virtnet_stats->rx_syncp);
1753         }
1754
1755         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1756
1757         /* If we can receive ANY GSO packets, we must allocate large ones. */
1758         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1759             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1760             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
1761             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
1762                 vi->big_packets = true;
1763
1764         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1765                 vi->mergeable_rx_bufs = true;
1766
1767         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT))
1768                 vi->any_header_sg = true;
1769
1770         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1771                 vi->has_cvq = true;
1772
1773         if (vi->any_header_sg) {
1774                 if (vi->mergeable_rx_bufs)
1775                         dev->needed_headroom = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1776                 else
1777                         dev->needed_headroom = sizeof(struct virtio_net_hdr);
1778         }
1779
1780         /* Use single tx/rx queue pair as default */
1781         vi->curr_queue_pairs = 1;
1782         vi->max_queue_pairs = max_queue_pairs;
1783
1784         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1785         err = init_vqs(vi);
1786         if (err)
1787                 goto free_stats;
1788
1789 #ifdef CONFIG_SYSFS
1790         if (vi->mergeable_rx_bufs)
1791                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
1792 #endif
1793         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
1794         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
1795
1796         err = register_netdev(dev);
1797         if (err) {
1798                 pr_debug("virtio_net: registering device failed\n");
1799                 goto free_vqs;
1800         }
1801
1802         virtio_device_ready(vdev);
1803
1804         /* Last of all, set up some receive buffers. */
1805         for (i = 0; i < vi->curr_queue_pairs; i++) {
1806                 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1807
1808                 /* If we didn't even get one input buffer, we're useless. */
1809                 if (vi->rq[i].vq->num_free ==
1810                     virtqueue_get_vring_size(vi->rq[i].vq)) {
1811                         free_unused_bufs(vi);
1812                         err = -ENOMEM;
1813                         goto free_recv_bufs;
1814                 }
1815         }
1816
1817         vi->nb.notifier_call = &virtnet_cpu_callback;
1818         err = register_hotcpu_notifier(&vi->nb);
1819         if (err) {
1820                 pr_debug("virtio_net: registering cpu notifier failed\n");
1821                 goto free_recv_bufs;
1822         }
1823
1824         /* Assume link up if device can't report link status,
1825            otherwise get link status from config. */
1826         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1827                 netif_carrier_off(dev);
1828                 schedule_work(&vi->config_work);
1829         } else {
1830                 vi->status = VIRTIO_NET_S_LINK_UP;
1831                 netif_carrier_on(dev);
1832         }
1833
1834         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1835                  dev->name, max_queue_pairs);
1836
1837         return 0;
1838
1839 free_recv_bufs:
1840         vi->vdev->config->reset(vdev);
1841
1842         free_receive_bufs(vi);
1843         unregister_netdev(dev);
1844 free_vqs:
1845         cancel_delayed_work_sync(&vi->refill);
1846         free_receive_page_frags(vi);
1847         virtnet_del_vqs(vi);
1848 free_stats:
1849         free_percpu(vi->stats);
1850 free:
1851         free_netdev(dev);
1852         return err;
1853 }
1854
1855 static void remove_vq_common(struct virtnet_info *vi)
1856 {
1857         vi->vdev->config->reset(vi->vdev);
1858
1859         /* Free unused buffers in both send and recv, if any. */
1860         free_unused_bufs(vi);
1861
1862         free_receive_bufs(vi);
1863
1864         free_receive_page_frags(vi);
1865
1866         virtnet_del_vqs(vi);
1867 }
1868
1869 static void virtnet_remove(struct virtio_device *vdev)
1870 {
1871         struct virtnet_info *vi = vdev->priv;
1872
1873         unregister_hotcpu_notifier(&vi->nb);
1874
1875         /* Make sure no work handler is accessing the device. */
1876         flush_work(&vi->config_work);
1877
1878         unregister_netdev(vi->dev);
1879
1880         remove_vq_common(vi);
1881
1882         free_percpu(vi->stats);
1883         free_netdev(vi->dev);
1884 }
1885
1886 #ifdef CONFIG_PM_SLEEP
1887 static int virtnet_freeze(struct virtio_device *vdev)
1888 {
1889         struct virtnet_info *vi = vdev->priv;
1890         int i;
1891
1892         unregister_hotcpu_notifier(&vi->nb);
1893
1894         /* Make sure no work handler is accessing the device */
1895         flush_work(&vi->config_work);
1896
1897         netif_device_detach(vi->dev);
1898         cancel_delayed_work_sync(&vi->refill);
1899
1900         if (netif_running(vi->dev)) {
1901                 for (i = 0; i < vi->max_queue_pairs; i++) {
1902                         napi_disable(&vi->rq[i].napi);
1903                         napi_hash_del(&vi->rq[i].napi);
1904                         netif_napi_del(&vi->rq[i].napi);
1905                 }
1906         }
1907
1908         remove_vq_common(vi);
1909
1910         return 0;
1911 }
1912
1913 static int virtnet_restore(struct virtio_device *vdev)
1914 {
1915         struct virtnet_info *vi = vdev->priv;
1916         int err, i;
1917
1918         err = init_vqs(vi);
1919         if (err)
1920                 return err;
1921
1922         virtio_device_ready(vdev);
1923
1924         if (netif_running(vi->dev)) {
1925                 for (i = 0; i < vi->curr_queue_pairs; i++)
1926                         if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1927                                 schedule_delayed_work(&vi->refill, 0);
1928
1929                 for (i = 0; i < vi->max_queue_pairs; i++)
1930                         virtnet_napi_enable(&vi->rq[i]);
1931         }
1932
1933         netif_device_attach(vi->dev);
1934
1935         rtnl_lock();
1936         virtnet_set_queues(vi, vi->curr_queue_pairs);
1937         rtnl_unlock();
1938
1939         err = register_hotcpu_notifier(&vi->nb);
1940         if (err)
1941                 return err;
1942
1943         return 0;
1944 }
1945 #endif
1946
1947 static struct virtio_device_id id_table[] = {
1948         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1949         { 0 },
1950 };
1951
1952 static unsigned int features[] = {
1953         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1954         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1955         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1956         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1957         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1958         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1959         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1960         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1961         VIRTIO_NET_F_CTRL_MAC_ADDR,
1962         VIRTIO_F_ANY_LAYOUT,
1963 };
1964
1965 static struct virtio_driver virtio_net_driver = {
1966         .feature_table = features,
1967         .feature_table_size = ARRAY_SIZE(features),
1968         .driver.name =  KBUILD_MODNAME,
1969         .driver.owner = THIS_MODULE,
1970         .id_table =     id_table,
1971         .probe =        virtnet_probe,
1972         .remove =       virtnet_remove,
1973         .config_changed = virtnet_config_changed,
1974 #ifdef CONFIG_PM_SLEEP
1975         .freeze =       virtnet_freeze,
1976         .restore =      virtnet_restore,
1977 #endif
1978 };
1979
1980 module_virtio_driver(virtio_net_driver);
1981
1982 MODULE_DEVICE_TABLE(virtio, id_table);
1983 MODULE_DESCRIPTION("Virtio network driver");
1984 MODULE_LICENSE("GPL");