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 /* RX packet size EWMA. The average packet size is used to determine the packet
  44  * buffer size when refilling RX rings. As the entire RX ring may be refilled
  45  * at once, the weight is chosen so that the EWMA will be insensitive to short-
  46  * term, transient changes in packet size.
  47  */
  48 DECLARE_EWMA(pkt_len, 1, 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.$index */
  74         char name[40];
  75 };
  76
  77 /* Internal representation of a receive virtqueue */
  78 struct receive_queue {
  79         /* Virtqueue associated with this receive_queue */
  80         struct virtqueue *vq;
  81
  82         struct napi_struct napi;
  83
  84         /* Chain pages by the private ptr. */
  85         struct page *pages;
  86
  87         /* Average packet length for mergeable receive buffers. */
  88         struct ewma_pkt_len mrg_avg_pkt_len;
  89
  90         /* Page frag for packet buffer allocation. */
  91         struct page_frag alloc_frag;
  92
  93         /* RX: fragments + linear part + virtio header */
  94         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  95
  96         /* Name of this receive queue: input.$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         /* Packet virtio header size */
 127         u8 hdr_len;
 128
 129         /* Active statistics */
 130         struct virtnet_stats __percpu *stats;
 131
 132         /* Work struct for refilling if we run low on memory. */
 133         struct delayed_work refill;
 134
 135         /* Work struct for config space updates */
 136         struct work_struct config_work;
 137
 138         /* Does the affinity hint is set for virtqueues? */
 139         bool affinity_hint_set;
 140
 141         /* CPU hot plug notifier */
 142         struct notifier_block nb;
 143
 144         /* Control VQ buffers: protected by the rtnl lock */
 145         struct virtio_net_ctrl_hdr ctrl_hdr;
 146         virtio_net_ctrl_ack ctrl_status;
 147         u8 ctrl_promisc;
 148         u8 ctrl_allmulti;
 149 };
 150
 151 struct padded_vnet_hdr {
 152         struct virtio_net_hdr_mrg_rxbuf hdr;
 153         /*
 154          * hdr is in a separate sg buffer, and data sg buffer shares same page
 155          * with this header sg. This padding makes next sg 16 byte aligned
 156          * after the header.
 157          */
 158         char padding[4];
 159 };
 160
 161 /* Converting between virtqueue no. and kernel tx/rx queue no.
 162  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 163  */
 164 static int vq2txq(struct virtqueue *vq)
 165 {
 166         return (vq->index - 1) / 2;
 167 }
 168
 169 static int txq2vq(int txq)
 170 {
 171         return txq * 2 + 1;
 172 }
 173
 174 static int vq2rxq(struct virtqueue *vq)
 175 {
 176         return vq->index / 2;
 177 }
 178
 179 static int rxq2vq(int rxq)
 180 {
 181         return rxq * 2;
 182 }
 183
 184 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 185 {
 186         return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
 187 }
 188
 189 /*
 190  * private is used to chain pages for big packets, put the whole
 191  * most recent used list in the beginning for reuse
 192  */
 193 static void give_pages(struct receive_queue *rq, struct page *page)
 194 {
 195         struct page *end;
 196
 197         /* Find end of list, sew whole thing into vi->rq.pages. */
 198         for (end = page; end->private; end = (struct page *)end->private);
 199         end->private = (unsigned long)rq->pages;
 200         rq->pages = page;
 201 }
 202
 203 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 204 {
 205         struct page *p = rq->pages;
 206
 207         if (p) {
 208                 rq->pages = (struct page *)p->private;
 209                 /* clear private here, it is used to chain pages */
 210                 p->private = 0;
 211         } else
 212                 p = alloc_page(gfp_mask);
 213         return p;
 214 }
 215
 216 static void skb_xmit_done(struct virtqueue *vq)
 217 {
 218         struct virtnet_info *vi = vq->vdev->priv;
 219
 220         /* Suppress further interrupts. */
 221         virtqueue_disable_cb(vq);
 222
 223         /* We were probably waiting for more output buffers. */
 224         netif_wake_subqueue(vi->dev, vq2txq(vq));
 225 }
 226
 227 static unsigned int mergeable_ctx_to_buf_truesize(unsigned long mrg_ctx)
 228 {
 229         unsigned int truesize = mrg_ctx & (MERGEABLE_BUFFER_ALIGN - 1);
 230         return (truesize + 1) * MERGEABLE_BUFFER_ALIGN;
 231 }
 232
 233 static void *mergeable_ctx_to_buf_address(unsigned long mrg_ctx)
 234 {
 235         return (void *)(mrg_ctx & -MERGEABLE_BUFFER_ALIGN);
 236
 237 }
 238
 239 static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize)
 240 {
 241         unsigned int size = truesize / MERGEABLE_BUFFER_ALIGN;
 242         return (unsigned long)buf | (size - 1);
 243 }
 244
 245 /* Called from bottom half context */
 246 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 247                                    struct receive_queue *rq,
 248                                    struct page *page, unsigned int offset,
 249                                    unsigned int len, unsigned int truesize)
 250 {
 251         struct sk_buff *skb;
 252         struct virtio_net_hdr_mrg_rxbuf *hdr;
 253         unsigned int copy, hdr_len, hdr_padded_len;
 254         char *p;
 255
 256         p = page_address(page) + offset;
 257
 258         /* copy small packet so we can reuse these pages for small data */
 259         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
 260         if (unlikely(!skb))
 261                 return NULL;
 262
 263         hdr = skb_vnet_hdr(skb);
 264
 265         hdr_len = vi->hdr_len;
 266         if (vi->mergeable_rx_bufs)
 267                 hdr_padded_len = sizeof *hdr;
 268         else
 269                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 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(struct virtnet_info *vi, void *buf, unsigned int len)
 321 {
 322         struct sk_buff * skb = buf;
 323
 324         len -= vi->hdr_len;
 325         skb_trim(skb, len);
 326
 327         return skb;
 328 }
 329
 330 static struct sk_buff *receive_big(struct net_device *dev,
 331                                    struct virtnet_info *vi,
 332                                    struct receive_queue *rq,
 333                                    void *buf,
 334                                    unsigned int len)
 335 {
 336         struct page *page = buf;
 337         struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
 338
 339         if (unlikely(!skb))
 340                 goto err;
 341
 342         return skb;
 343
 344 err:
 345         dev->stats.rx_dropped++;
 346         give_pages(rq, page);
 347         return NULL;
 348 }
 349
 350 static struct sk_buff *receive_mergeable(struct net_device *dev,
 351                                          struct virtnet_info *vi,
 352                                          struct receive_queue *rq,
 353                                          unsigned long ctx,
 354                                          unsigned int len)
 355 {
 356         void *buf = mergeable_ctx_to_buf_address(ctx);
 357         struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
 358         u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
 359         struct page *page = virt_to_head_page(buf);
 360         int offset = buf - page_address(page);
 361         unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 362
 363         struct sk_buff *head_skb = page_to_skb(vi, rq, page, offset, len,
 364                                                truesize);
 365         struct sk_buff *curr_skb = head_skb;
 366
 367         if (unlikely(!curr_skb))
 368                 goto err_skb;
 369         while (--num_buf) {
 370                 int num_skb_frags;
 371
 372                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 373                 if (unlikely(!ctx)) {
 374                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
 375                                  dev->name, num_buf,
 376                                  virtio16_to_cpu(vi->vdev,
 377                                                  hdr->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_pkt_len_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 virtnet_info *vi, struct receive_queue *rq,
 439                         void *buf, unsigned int len)
 440 {
 441         struct net_device *dev = vi->dev;
 442         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 443         struct sk_buff *skb;
 444         struct virtio_net_hdr_mrg_rxbuf *hdr;
 445
 446         if (unlikely(len < vi->hdr_len + 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, vi, rq, (unsigned long)buf, len);
 463         else if (vi->big_packets)
 464                 skb = receive_big(dev, vi, rq, buf, len);
 465         else
 466                 skb = receive_small(vi, 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                           virtio16_to_cpu(vi->vdev, hdr->hdr.csum_start),
 482                           virtio16_to_cpu(vi->vdev, hdr->hdr.csum_offset)))
 483                         goto frame_err;
 484         } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
 485                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 486         }
 487
 488         skb->protocol = eth_type_trans(skb, dev);
 489         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 490                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 491
 492         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 493                 pr_debug("GSO!\n");
 494                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 495                 case VIRTIO_NET_HDR_GSO_TCPV4:
 496                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 497                         break;
 498                 case VIRTIO_NET_HDR_GSO_UDP:
 499                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 500                         break;
 501                 case VIRTIO_NET_HDR_GSO_TCPV6:
 502                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 503                         break;
 504                 default:
 505                         net_warn_ratelimited("%s: bad gso type %u.\n",
 506                                              dev->name, hdr->hdr.gso_type);
 507                         goto frame_err;
 508                 }
 509
 510                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 511                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 512
 513                 skb_shinfo(skb)->gso_size = virtio16_to_cpu(vi->vdev,
 514                                                             hdr->hdr.gso_size);
 515                 if (skb_shinfo(skb)->gso_size == 0) {
 516                         net_warn_ratelimited("%s: zero gso size.\n", dev->name);
 517                         goto frame_err;
 518                 }
 519
 520                 /* Header must be checked, and gso_segs computed. */
 521                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 522                 skb_shinfo(skb)->gso_segs = 0;
 523         }
 524
 525         napi_gro_receive(&rq->napi, skb);
 526         return;
 527
 528 frame_err:
 529         dev->stats.rx_frame_errors++;
 530         dev_kfree_skb(skb);
 531 }
 532
 533 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 534                              gfp_t gfp)
 535 {
 536         struct sk_buff *skb;
 537         struct virtio_net_hdr_mrg_rxbuf *hdr;
 538         int err;
 539
 540         skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
 541         if (unlikely(!skb))
 542                 return -ENOMEM;
 543
 544         skb_put(skb, GOOD_PACKET_LEN);
 545
 546         hdr = skb_vnet_hdr(skb);
 547         sg_init_table(rq->sg, 2);
 548         sg_set_buf(rq->sg, hdr, vi->hdr_len);
 549         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 550
 551         err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
 552         if (err < 0)
 553                 dev_kfree_skb(skb);
 554
 555         return err;
 556 }
 557
 558 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
 559                            gfp_t gfp)
 560 {
 561         struct page *first, *list = NULL;
 562         char *p;
 563         int i, err, offset;
 564
 565         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
 566
 567         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 568         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 569                 first = get_a_page(rq, gfp);
 570                 if (!first) {
 571                         if (list)
 572                                 give_pages(rq, list);
 573                         return -ENOMEM;
 574                 }
 575                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
 576
 577                 /* chain new page in list head to match sg */
 578                 first->private = (unsigned long)list;
 579                 list = first;
 580         }
 581
 582         first = get_a_page(rq, gfp);
 583         if (!first) {
 584                 give_pages(rq, list);
 585                 return -ENOMEM;
 586         }
 587         p = page_address(first);
 588
 589         /* rq->sg[0], rq->sg[1] share the same page */
 590         /* a separated rq->sg[0] for header - required in case !any_header_sg */
 591         sg_set_buf(&rq->sg[0], p, vi->hdr_len);
 592
 593         /* rq->sg[1] for data packet, from offset */
 594         offset = sizeof(struct padded_vnet_hdr);
 595         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
 596
 597         /* chain first in list head */
 598         first->private = (unsigned long)list;
 599         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
 600                                   first, gfp);
 601         if (err < 0)
 602                 give_pages(rq, first);
 603
 604         return err;
 605 }
 606
 607 static unsigned int get_mergeable_buf_len(struct ewma_pkt_len *avg_pkt_len)
 608 {
 609         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 610         unsigned int len;
 611
 612         len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
 613                         GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
 614         return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
 615 }
 616
 617 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
 618 {
 619         struct page_frag *alloc_frag = &rq->alloc_frag;
 620         char *buf;
 621         unsigned long ctx;
 622         int err;
 623         unsigned int len, hole;
 624
 625         len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
 626         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
 627                 return -ENOMEM;
 628
 629         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
 630         ctx = mergeable_buf_to_ctx(buf, len);
 631         get_page(alloc_frag->page);
 632         alloc_frag->offset += len;
 633         hole = alloc_frag->size - alloc_frag->offset;
 634         if (hole < len) {
 635                 /* To avoid internal fragmentation, if there is very likely not
 636                  * enough space for another buffer, add the remaining space to
 637                  * the current buffer. This extra space is not included in
 638                  * the truesize stored in ctx.
 639                  */
 640                 len += hole;
 641                 alloc_frag->offset += hole;
 642         }
 643
 644         sg_init_one(rq->sg, buf, len);
 645         err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
 646         if (err < 0)
 647                 put_page(virt_to_head_page(buf));
 648
 649         return err;
 650 }
 651
 652 /*
 653  * Returns false if we couldn't fill entirely (OOM).
 654  *
 655  * Normally run in the receive path, but can also be run from ndo_open
 656  * before we're receiving packets, or from refill_work which is
 657  * careful to disable receiving (using napi_disable).
 658  */
 659 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
 660                           gfp_t gfp)
 661 {
 662         int err;
 663         bool oom;
 664
 665         gfp |= __GFP_COLD;
 666         do {
 667                 if (vi->mergeable_rx_bufs)
 668                         err = add_recvbuf_mergeable(rq, gfp);
 669                 else if (vi->big_packets)
 670                         err = add_recvbuf_big(vi, rq, gfp);
 671                 else
 672                         err = add_recvbuf_small(vi, rq, gfp);
 673
 674                 oom = err == -ENOMEM;
 675                 if (err)
 676                         break;
 677         } while (rq->vq->num_free);
 678         virtqueue_kick(rq->vq);
 679         return !oom;
 680 }
 681
 682 static void skb_recv_done(struct virtqueue *rvq)
 683 {
 684         struct virtnet_info *vi = rvq->vdev->priv;
 685         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 686
 687         /* Schedule NAPI, Suppress further interrupts if successful. */
 688         if (napi_schedule_prep(&rq->napi)) {
 689                 virtqueue_disable_cb(rvq);
 690                 __napi_schedule(&rq->napi);
 691         }
 692 }
 693
 694 static void virtnet_napi_enable(struct receive_queue *rq)
 695 {
 696         napi_enable(&rq->napi);
 697
 698         /* If all buffers were filled by other side before we napi_enabled, we
 699          * won't get another interrupt, so process any outstanding packets
 700          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 701          * We synchronize against interrupts via NAPI_STATE_SCHED */
 702         if (napi_schedule_prep(&rq->napi)) {
 703                 virtqueue_disable_cb(rq->vq);
 704                 local_bh_disable();
 705                 __napi_schedule(&rq->napi);
 706                 local_bh_enable();
 707         }
 708 }
 709
 710 static void refill_work(struct work_struct *work)
 711 {
 712         struct virtnet_info *vi =
 713                 container_of(work, struct virtnet_info, refill.work);
 714         bool still_empty;
 715         int i;
 716
 717         for (i = 0; i < vi->curr_queue_pairs; i++) {
 718                 struct receive_queue *rq = &vi->rq[i];
 719
 720                 napi_disable(&rq->napi);
 721                 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
 722                 virtnet_napi_enable(rq);
 723
 724                 /* In theory, this can happen: if we don't get any buffers in
 725                  * we will *never* try to fill again.
 726                  */
 727                 if (still_empty)
 728                         schedule_delayed_work(&vi->refill, HZ/2);
 729         }
 730 }
 731
 732 static int virtnet_receive(struct receive_queue *rq, int budget)
 733 {
 734         struct virtnet_info *vi = rq->vq->vdev->priv;
 735         unsigned int len, received = 0;
 736         void *buf;
 737
 738         while (received < budget &&
 739                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
 740                 receive_buf(vi, rq, buf, len);
 741                 received++;
 742         }
 743
 744         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
 745                 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
 746                         schedule_delayed_work(&vi->refill, 0);
 747         }
 748
 749         return received;
 750 }
 751
 752 static int virtnet_poll(struct napi_struct *napi, int budget)
 753 {
 754         struct receive_queue *rq =
 755                 container_of(napi, struct receive_queue, napi);
 756         unsigned int r, received;
 757
 758         received = virtnet_receive(rq, budget);
 759
 760         /* Out of packets? */
 761         if (received < budget) {
 762                 r = virtqueue_enable_cb_prepare(rq->vq);
 763                 napi_complete_done(napi, received);
 764                 if (unlikely(virtqueue_poll(rq->vq, r)) &&
 765                     napi_schedule_prep(napi)) {
 766                         virtqueue_disable_cb(rq->vq);
 767                         __napi_schedule(napi);
 768                 }
 769         }
 770
 771         return received;
 772 }
 773
 774 #ifdef CONFIG_NET_RX_BUSY_POLL
 775 /* must be called with local_bh_disable()d */
 776 static int virtnet_busy_poll(struct napi_struct *napi)
 777 {
 778         struct receive_queue *rq =
 779                 container_of(napi, struct receive_queue, napi);
 780         struct virtnet_info *vi = rq->vq->vdev->priv;
 781         int r, received = 0, budget = 4;
 782
 783         if (!(vi->status & VIRTIO_NET_S_LINK_UP))
 784                 return LL_FLUSH_FAILED;
 785
 786         if (!napi_schedule_prep(napi))
 787                 return LL_FLUSH_BUSY;
 788
 789         virtqueue_disable_cb(rq->vq);
 790
 791 again:
 792         received += virtnet_receive(rq, budget);
 793
 794         r = virtqueue_enable_cb_prepare(rq->vq);
 795         clear_bit(NAPI_STATE_SCHED, &napi->state);
 796         if (unlikely(virtqueue_poll(rq->vq, r)) &&
 797             napi_schedule_prep(napi)) {
 798                 virtqueue_disable_cb(rq->vq);
 799                 if (received < budget) {
 800                         budget -= received;
 801                         goto again;
 802                 } else {
 803                         __napi_schedule(napi);
 804                 }
 805         }
 806
 807         return received;
 808 }
 809 #endif  /* CONFIG_NET_RX_BUSY_POLL */
 810
 811 static int virtnet_open(struct net_device *dev)
 812 {
 813         struct virtnet_info *vi = netdev_priv(dev);
 814         int i;
 815
 816         for (i = 0; i < vi->max_queue_pairs; i++) {
 817                 if (i < vi->curr_queue_pairs)
 818                         /* Make sure we have some buffers: if oom use wq. */
 819                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
 820                                 schedule_delayed_work(&vi->refill, 0);
 821                 virtnet_napi_enable(&vi->rq[i]);
 822         }
 823
 824         return 0;
 825 }
 826
 827 static void free_old_xmit_skbs(struct send_queue *sq)
 828 {
 829         struct sk_buff *skb;
 830         unsigned int len;
 831         struct virtnet_info *vi = sq->vq->vdev->priv;
 832         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 833
 834         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 835                 pr_debug("Sent skb %p\n", skb);
 836
 837                 u64_stats_update_begin(&stats->tx_syncp);
 838                 stats->tx_bytes += skb->len;
 839                 stats->tx_packets++;
 840                 u64_stats_update_end(&stats->tx_syncp);
 841
 842                 dev_kfree_skb_any(skb);
 843         }
 844 }
 845
 846 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 847 {
 848         struct virtio_net_hdr_mrg_rxbuf *hdr;
 849         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 850         struct virtnet_info *vi = sq->vq->vdev->priv;
 851         unsigned num_sg;
 852         unsigned hdr_len = vi->hdr_len;
 853         bool can_push;
 854
 855         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 856
 857         can_push = vi->any_header_sg &&
 858                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
 859                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
 860         /* Even if we can, don't push here yet as this would skew
 861          * csum_start offset below. */
 862         if (can_push)
 863                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
 864         else
 865                 hdr = skb_vnet_hdr(skb);
 866
 867         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 868                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 869                 hdr->hdr.csum_start = cpu_to_virtio16(vi->vdev,
 870                                                 skb_checksum_start_offset(skb));
 871                 hdr->hdr.csum_offset = cpu_to_virtio16(vi->vdev,
 872                                                          skb->csum_offset);
 873         } else {
 874                 hdr->hdr.flags = 0;
 875                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 876         }
 877
 878         if (skb_is_gso(skb)) {
 879                 hdr->hdr.hdr_len = cpu_to_virtio16(vi->vdev, skb_headlen(skb));
 880                 hdr->hdr.gso_size = cpu_to_virtio16(vi->vdev,
 881                                                     skb_shinfo(skb)->gso_size);
 882                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 883                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 884                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 885                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 886                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 887                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 888                 else
 889                         BUG();
 890                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 891                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 892         } else {
 893                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 894                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
 895         }
 896
 897         if (vi->mergeable_rx_bufs)
 898                 hdr->num_buffers = 0;
 899
 900         sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
 901         if (can_push) {
 902                 __skb_push(skb, hdr_len);
 903                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
 904                 /* Pull header back to avoid skew in tx bytes calculations. */
 905                 __skb_pull(skb, hdr_len);
 906         } else {
 907                 sg_set_buf(sq->sg, hdr, hdr_len);
 908                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
 909         }
 910         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
 911 }
 912
 913 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 914 {
 915         struct virtnet_info *vi = netdev_priv(dev);
 916         int qnum = skb_get_queue_mapping(skb);
 917         struct send_queue *sq = &vi->sq[qnum];
 918         int err;
 919         struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
 920         bool kick = !skb->xmit_more;
 921
 922         /* Free up any pending old buffers before queueing new ones. */
 923         free_old_xmit_skbs(sq);
 924
 925         /* timestamp packet in software */
 926         skb_tx_timestamp(skb);
 927
 928         /* Try to transmit */
 929         err = xmit_skb(sq, skb);
 930
 931         /* This should not happen! */
 932         if (unlikely(err)) {
 933                 dev->stats.tx_fifo_errors++;
 934                 if (net_ratelimit())
 935                         dev_warn(&dev->dev,
 936                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
 937                 dev->stats.tx_dropped++;
 938                 dev_kfree_skb_any(skb);
 939                 return NETDEV_TX_OK;
 940         }
 941
 942         /* Don't wait up for transmitted skbs to be freed. */
 943         skb_orphan(skb);
 944         nf_reset(skb);
 945
 946         /* If running out of space, stop queue to avoid getting packets that we
 947          * are then unable to transmit.
 948          * An alternative would be to force queuing layer to requeue the skb by
 949          * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
 950          * returned in a normal path of operation: it means that driver is not
 951          * maintaining the TX queue stop/start state properly, and causes
 952          * the stack to do a non-trivial amount of useless work.
 953          * Since most packets only take 1 or 2 ring slots, stopping the queue
 954          * early means 16 slots are typically wasted.
 955          */
 956         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
 957                 netif_stop_subqueue(dev, qnum);
 958                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 959                         /* More just got used, free them then recheck. */
 960                         free_old_xmit_skbs(sq);
 961                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
 962                                 netif_start_subqueue(dev, qnum);
 963                                 virtqueue_disable_cb(sq->vq);
 964                         }
 965                 }
 966         }
 967
 968         if (kick || netif_xmit_stopped(txq))
 969                 virtqueue_kick(sq->vq);
 970
 971         return NETDEV_TX_OK;
 972 }
 973
 974 /*
 975  * Send command via the control virtqueue and check status.  Commands
 976  * supported by the hypervisor, as indicated by feature bits, should
 977  * never fail unless improperly formatted.
 978  */
 979 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 980                                  struct scatterlist *out)
 981 {
 982         struct scatterlist *sgs[4], hdr, stat;
 983         unsigned out_num = 0, tmp;
 984
 985         /* Caller should know better */
 986         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
 987
 988         vi->ctrl_status = ~0;
 989         vi->ctrl_hdr.class = class;
 990         vi->ctrl_hdr.cmd = cmd;
 991         /* Add header */
 992         sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr));
 993         sgs[out_num++] = &hdr;
 994
 995         if (out)
 996                 sgs[out_num++] = out;
 997
 998         /* Add return status. */
 999         sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status));
1000         sgs[out_num] = &stat;
1001
1002         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
1003         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
1004
1005         if (unlikely(!virtqueue_kick(vi->cvq)))
1006                 return vi->ctrl_status == VIRTIO_NET_OK;
1007
1008         /* Spin for a response, the kick causes an ioport write, trapping
1009          * into the hypervisor, so the request should be handled immediately.
1010          */
1011         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1012                !virtqueue_is_broken(vi->cvq))
1013                 cpu_relax();
1014
1015         return vi->ctrl_status == VIRTIO_NET_OK;
1016 }
1017
1018 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1019 {
1020         struct virtnet_info *vi = netdev_priv(dev);
1021         struct virtio_device *vdev = vi->vdev;
1022         int ret;
1023         struct sockaddr *addr = p;
1024         struct scatterlist sg;
1025
1026         ret = eth_prepare_mac_addr_change(dev, p);
1027         if (ret)
1028                 return ret;
1029
1030         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1031                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1032                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1033                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1034                         dev_warn(&vdev->dev,
1035                                  "Failed to set mac address by vq command.\n");
1036                         return -EINVAL;
1037                 }
1038         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
1039                    !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
1040                 unsigned int i;
1041
1042                 /* Naturally, this has an atomicity problem. */
1043                 for (i = 0; i < dev->addr_len; i++)
1044                         virtio_cwrite8(vdev,
1045                                        offsetof(struct virtio_net_config, mac) +
1046                                        i, addr->sa_data[i]);
1047         }
1048
1049         eth_commit_mac_addr_change(dev, p);
1050
1051         return 0;
1052 }
1053
1054 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
1055                                                struct rtnl_link_stats64 *tot)
1056 {
1057         struct virtnet_info *vi = netdev_priv(dev);
1058         int cpu;
1059         unsigned int start;
1060
1061         for_each_possible_cpu(cpu) {
1062                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1063                 u64 tpackets, tbytes, rpackets, rbytes;
1064
1065                 do {
1066                         start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
1067                         tpackets = stats->tx_packets;
1068                         tbytes   = stats->tx_bytes;
1069                 } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
1070
1071                 do {
1072                         start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
1073                         rpackets = stats->rx_packets;
1074                         rbytes   = stats->rx_bytes;
1075                 } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
1076
1077                 tot->rx_packets += rpackets;
1078                 tot->tx_packets += tpackets;
1079                 tot->rx_bytes   += rbytes;
1080                 tot->tx_bytes   += tbytes;
1081         }
1082
1083         tot->tx_dropped = dev->stats.tx_dropped;
1084         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1085         tot->rx_dropped = dev->stats.rx_dropped;
1086         tot->rx_length_errors = dev->stats.rx_length_errors;
1087         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1088
1089         return tot;
1090 }
1091
1092 #ifdef CONFIG_NET_POLL_CONTROLLER
1093 static void virtnet_netpoll(struct net_device *dev)
1094 {
1095         struct virtnet_info *vi = netdev_priv(dev);
1096         int i;
1097
1098         for (i = 0; i < vi->curr_queue_pairs; i++)
1099                 napi_schedule(&vi->rq[i].napi);
1100 }
1101 #endif
1102
1103 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1104 {
1105         rtnl_lock();
1106         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1107                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1108                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1109         rtnl_unlock();
1110 }
1111
1112 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1113 {
1114         struct scatterlist sg;
1115         struct virtio_net_ctrl_mq s;
1116         struct net_device *dev = vi->dev;
1117
1118         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1119                 return 0;
1120
1121         s.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1122         sg_init_one(&sg, &s, sizeof(s));
1123
1124         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1125                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1126                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1127                          queue_pairs);
1128                 return -EINVAL;
1129         } else {
1130                 vi->curr_queue_pairs = queue_pairs;
1131                 /* virtnet_open() will refill when device is going to up. */
1132                 if (dev->flags & IFF_UP)
1133                         schedule_delayed_work(&vi->refill, 0);
1134         }
1135
1136         return 0;
1137 }
1138
1139 static int virtnet_close(struct net_device *dev)
1140 {
1141         struct virtnet_info *vi = netdev_priv(dev);
1142         int i;
1143
1144         /* Make sure refill_work doesn't re-enable napi! */
1145         cancel_delayed_work_sync(&vi->refill);
1146
1147         for (i = 0; i < vi->max_queue_pairs; i++)
1148                 napi_disable(&vi->rq[i].napi);
1149
1150         return 0;
1151 }
1152
1153 static void virtnet_set_rx_mode(struct net_device *dev)
1154 {
1155         struct virtnet_info *vi = netdev_priv(dev);
1156         struct scatterlist sg[2];
1157         struct virtio_net_ctrl_mac *mac_data;
1158         struct netdev_hw_addr *ha;
1159         int uc_count;
1160         int mc_count;
1161         void *buf;
1162         int i;
1163
1164         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1165         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1166                 return;
1167
1168         vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0);
1169         vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1170
1171         sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc));
1172
1173         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1174                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1175                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1176                          vi->ctrl_promisc ? "en" : "dis");
1177
1178         sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti));
1179
1180         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1181                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1182                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1183                          vi->ctrl_allmulti ? "en" : "dis");
1184
1185         uc_count = netdev_uc_count(dev);
1186         mc_count = netdev_mc_count(dev);
1187         /* MAC filter - use one buffer for both lists */
1188         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1189                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1190         mac_data = buf;
1191         if (!buf)
1192                 return;
1193
1194         sg_init_table(sg, 2);
1195
1196         /* Store the unicast list and count in the front of the buffer */
1197         mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1198         i = 0;
1199         netdev_for_each_uc_addr(ha, dev)
1200                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1201
1202         sg_set_buf(&sg[0], mac_data,
1203                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1204
1205         /* multicast list and count fill the end */
1206         mac_data = (void *)&mac_data->macs[uc_count][0];
1207
1208         mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1209         i = 0;
1210         netdev_for_each_mc_addr(ha, dev)
1211                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1212
1213         sg_set_buf(&sg[1], mac_data,
1214                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1215
1216         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1217                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1218                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1219
1220         kfree(buf);
1221 }
1222
1223 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1224                                    __be16 proto, u16 vid)
1225 {
1226         struct virtnet_info *vi = netdev_priv(dev);
1227         struct scatterlist sg;
1228
1229         sg_init_one(&sg, &vid, sizeof(vid));
1230
1231         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1232                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1233                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1234         return 0;
1235 }
1236
1237 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1238                                     __be16 proto, u16 vid)
1239 {
1240         struct virtnet_info *vi = netdev_priv(dev);
1241         struct scatterlist sg;
1242
1243         sg_init_one(&sg, &vid, sizeof(vid));
1244
1245         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1246                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1247                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1248         return 0;
1249 }
1250
1251 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1252 {
1253         int i;
1254
1255         if (vi->affinity_hint_set) {
1256                 for (i = 0; i < vi->max_queue_pairs; i++) {
1257                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1258                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1259                 }
1260
1261                 vi->affinity_hint_set = false;
1262         }
1263 }
1264
1265 static void virtnet_set_affinity(struct virtnet_info *vi)
1266 {
1267         int i;
1268         int cpu;
1269
1270         /* In multiqueue mode, when the number of cpu is equal to the number of
1271          * queue pairs, we let the queue pairs to be private to one cpu by
1272          * setting the affinity hint to eliminate the contention.
1273          */
1274         if (vi->curr_queue_pairs == 1 ||
1275             vi->max_queue_pairs != num_online_cpus()) {
1276                 virtnet_clean_affinity(vi, -1);
1277                 return;
1278         }
1279
1280         i = 0;
1281         for_each_online_cpu(cpu) {
1282                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1283                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1284                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1285                 i++;
1286         }
1287
1288         vi->affinity_hint_set = true;
1289 }
1290
1291 static int virtnet_cpu_callback(struct notifier_block *nfb,
1292                                 unsigned long action, void *hcpu)
1293 {
1294         struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);
1295
1296         switch(action & ~CPU_TASKS_FROZEN) {
1297         case CPU_ONLINE:
1298         case CPU_DOWN_FAILED:
1299         case CPU_DEAD:
1300                 virtnet_set_affinity(vi);
1301                 break;
1302         case CPU_DOWN_PREPARE:
1303                 virtnet_clean_affinity(vi, (long)hcpu);
1304                 break;
1305         default:
1306                 break;
1307         }
1308
1309         return NOTIFY_OK;
1310 }
1311
1312 static void virtnet_get_ringparam(struct net_device *dev,
1313                                 struct ethtool_ringparam *ring)
1314 {
1315         struct virtnet_info *vi = netdev_priv(dev);
1316
1317         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1318         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1319         ring->rx_pending = ring->rx_max_pending;
1320         ring->tx_pending = ring->tx_max_pending;
1321 }
1322
1323
1324 static void virtnet_get_drvinfo(struct net_device *dev,
1325                                 struct ethtool_drvinfo *info)
1326 {
1327         struct virtnet_info *vi = netdev_priv(dev);
1328         struct virtio_device *vdev = vi->vdev;
1329
1330         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1331         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1332         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1333
1334 }
1335
1336 /* TODO: Eliminate OOO packets during switching */
1337 static int virtnet_set_channels(struct net_device *dev,
1338                                 struct ethtool_channels *channels)
1339 {
1340         struct virtnet_info *vi = netdev_priv(dev);
1341         u16 queue_pairs = channels->combined_count;
1342         int err;
1343
1344         /* We don't support separate rx/tx channels.
1345          * We don't allow setting 'other' channels.
1346          */
1347         if (channels->rx_count || channels->tx_count || channels->other_count)
1348                 return -EINVAL;
1349
1350         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1351                 return -EINVAL;
1352
1353         get_online_cpus();
1354         err = virtnet_set_queues(vi, queue_pairs);
1355         if (!err) {
1356                 netif_set_real_num_tx_queues(dev, queue_pairs);
1357                 netif_set_real_num_rx_queues(dev, queue_pairs);
1358
1359                 virtnet_set_affinity(vi);
1360         }
1361         put_online_cpus();
1362
1363         return err;
1364 }
1365
1366 static void virtnet_get_channels(struct net_device *dev,
1367                                  struct ethtool_channels *channels)
1368 {
1369         struct virtnet_info *vi = netdev_priv(dev);
1370
1371         channels->combined_count = vi->curr_queue_pairs;
1372         channels->max_combined = vi->max_queue_pairs;
1373         channels->max_other = 0;
1374         channels->rx_count = 0;
1375         channels->tx_count = 0;
1376         channels->other_count = 0;
1377 }
1378
1379 static const struct ethtool_ops virtnet_ethtool_ops = {
1380         .get_drvinfo = virtnet_get_drvinfo,
1381         .get_link = ethtool_op_get_link,
1382         .get_ringparam = virtnet_get_ringparam,
1383         .set_channels = virtnet_set_channels,
1384         .get_channels = virtnet_get_channels,
1385         .get_ts_info = ethtool_op_get_ts_info,
1386 };
1387
1388 #define MIN_MTU 68
1389 #define MAX_MTU 65535
1390
1391 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1392 {
1393         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1394                 return -EINVAL;
1395         dev->mtu = new_mtu;
1396         return 0;
1397 }
1398
1399 static const struct net_device_ops virtnet_netdev = {
1400         .ndo_open            = virtnet_open,
1401         .ndo_stop            = virtnet_close,
1402         .ndo_start_xmit      = start_xmit,
1403         .ndo_validate_addr   = eth_validate_addr,
1404         .ndo_set_mac_address = virtnet_set_mac_address,
1405         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1406         .ndo_change_mtu      = virtnet_change_mtu,
1407         .ndo_get_stats64     = virtnet_stats,
1408         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1409         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1410 #ifdef CONFIG_NET_POLL_CONTROLLER
1411         .ndo_poll_controller = virtnet_netpoll,
1412 #endif
1413 #ifdef CONFIG_NET_RX_BUSY_POLL
1414         .ndo_busy_poll          = virtnet_busy_poll,
1415 #endif
1416 };
1417
1418 static void virtnet_config_changed_work(struct work_struct *work)
1419 {
1420         struct virtnet_info *vi =
1421                 container_of(work, struct virtnet_info, config_work);
1422         u16 v;
1423
1424         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
1425                                  struct virtio_net_config, status, &v) < 0)
1426                 return;
1427
1428         if (v & VIRTIO_NET_S_ANNOUNCE) {
1429                 netdev_notify_peers(vi->dev);
1430                 virtnet_ack_link_announce(vi);
1431         }
1432
1433         /* Ignore unknown (future) status bits */
1434         v &= VIRTIO_NET_S_LINK_UP;
1435
1436         if (vi->status == v)
1437                 return;
1438
1439         vi->status = v;
1440
1441         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1442                 netif_carrier_on(vi->dev);
1443                 netif_tx_wake_all_queues(vi->dev);
1444         } else {
1445                 netif_carrier_off(vi->dev);
1446                 netif_tx_stop_all_queues(vi->dev);
1447         }
1448 }
1449
1450 static void virtnet_config_changed(struct virtio_device *vdev)
1451 {
1452         struct virtnet_info *vi = vdev->priv;
1453
1454         schedule_work(&vi->config_work);
1455 }
1456
1457 static void virtnet_free_queues(struct virtnet_info *vi)
1458 {
1459         int i;
1460
1461         for (i = 0; i < vi->max_queue_pairs; i++) {
1462                 napi_hash_del(&vi->rq[i].napi);
1463                 netif_napi_del(&vi->rq[i].napi);
1464         }
1465
1466         kfree(vi->rq);
1467         kfree(vi->sq);
1468 }
1469
1470 static void free_receive_bufs(struct virtnet_info *vi)
1471 {
1472         int i;
1473
1474         for (i = 0; i < vi->max_queue_pairs; i++) {
1475                 while (vi->rq[i].pages)
1476                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1477         }
1478 }
1479
1480 static void free_receive_page_frags(struct virtnet_info *vi)
1481 {
1482         int i;
1483         for (i = 0; i < vi->max_queue_pairs; i++)
1484                 if (vi->rq[i].alloc_frag.page)
1485                         put_page(vi->rq[i].alloc_frag.page);
1486 }
1487
1488 static void free_unused_bufs(struct virtnet_info *vi)
1489 {
1490         void *buf;
1491         int i;
1492
1493         for (i = 0; i < vi->max_queue_pairs; i++) {
1494                 struct virtqueue *vq = vi->sq[i].vq;
1495                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1496                         dev_kfree_skb(buf);
1497         }
1498
1499         for (i = 0; i < vi->max_queue_pairs; i++) {
1500                 struct virtqueue *vq = vi->rq[i].vq;
1501
1502                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1503                         if (vi->mergeable_rx_bufs) {
1504                                 unsigned long ctx = (unsigned long)buf;
1505                                 void *base = mergeable_ctx_to_buf_address(ctx);
1506                                 put_page(virt_to_head_page(base));
1507                         } else if (vi->big_packets) {
1508                                 give_pages(&vi->rq[i], buf);
1509                         } else {
1510                                 dev_kfree_skb(buf);
1511                         }
1512                 }
1513         }
1514 }
1515
1516 static void virtnet_del_vqs(struct virtnet_info *vi)
1517 {
1518         struct virtio_device *vdev = vi->vdev;
1519
1520         virtnet_clean_affinity(vi, -1);
1521
1522         vdev->config->del_vqs(vdev);
1523
1524         virtnet_free_queues(vi);
1525 }
1526
1527 static int virtnet_find_vqs(struct virtnet_info *vi)
1528 {
1529         vq_callback_t **callbacks;
1530         struct virtqueue **vqs;
1531         int ret = -ENOMEM;
1532         int i, total_vqs;
1533         const char **names;
1534
1535         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1536          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1537          * possible control vq.
1538          */
1539         total_vqs = vi->max_queue_pairs * 2 +
1540                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1541
1542         /* Allocate space for find_vqs parameters */
1543         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1544         if (!vqs)
1545                 goto err_vq;
1546         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1547         if (!callbacks)
1548                 goto err_callback;
1549         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1550         if (!names)
1551                 goto err_names;
1552
1553         /* Parameters for control virtqueue, if any */
1554         if (vi->has_cvq) {
1555                 callbacks[total_vqs - 1] = NULL;
1556                 names[total_vqs - 1] = "control";
1557         }
1558
1559         /* Allocate/initialize parameters for send/receive virtqueues */
1560         for (i = 0; i < vi->max_queue_pairs; i++) {
1561                 callbacks[rxq2vq(i)] = skb_recv_done;
1562                 callbacks[txq2vq(i)] = skb_xmit_done;
1563                 sprintf(vi->rq[i].name, "input.%d", i);
1564                 sprintf(vi->sq[i].name, "output.%d", i);
1565                 names[rxq2vq(i)] = vi->rq[i].name;
1566                 names[txq2vq(i)] = vi->sq[i].name;
1567         }
1568
1569         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1570                                          names);
1571         if (ret)
1572                 goto err_find;
1573
1574         if (vi->has_cvq) {
1575                 vi->cvq = vqs[total_vqs - 1];
1576                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1577                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1578         }
1579
1580         for (i = 0; i < vi->max_queue_pairs; i++) {
1581                 vi->rq[i].vq = vqs[rxq2vq(i)];
1582                 vi->sq[i].vq = vqs[txq2vq(i)];
1583         }
1584
1585         kfree(names);
1586         kfree(callbacks);
1587         kfree(vqs);
1588
1589         return 0;
1590
1591 err_find:
1592         kfree(names);
1593 err_names:
1594         kfree(callbacks);
1595 err_callback:
1596         kfree(vqs);
1597 err_vq:
1598         return ret;
1599 }
1600
1601 static int virtnet_alloc_queues(struct virtnet_info *vi)
1602 {
1603         int i;
1604
1605         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1606         if (!vi->sq)
1607                 goto err_sq;
1608         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1609         if (!vi->rq)
1610                 goto err_rq;
1611
1612         INIT_DELAYED_WORK(&vi->refill, refill_work);
1613         for (i = 0; i < vi->max_queue_pairs; i++) {
1614                 vi->rq[i].pages = NULL;
1615                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1616                                napi_weight);
1617
1618                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1619                 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
1620                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1621         }
1622
1623         return 0;
1624
1625 err_rq:
1626         kfree(vi->sq);
1627 err_sq:
1628         return -ENOMEM;
1629 }
1630
1631 static int init_vqs(struct virtnet_info *vi)
1632 {
1633         int ret;
1634
1635         /* Allocate send & receive queues */
1636         ret = virtnet_alloc_queues(vi);
1637         if (ret)
1638                 goto err;
1639
1640         ret = virtnet_find_vqs(vi);
1641         if (ret)
1642                 goto err_free;
1643
1644         get_online_cpus();
1645         virtnet_set_affinity(vi);
1646         put_online_cpus();
1647
1648         return 0;
1649
1650 err_free:
1651         virtnet_free_queues(vi);
1652 err:
1653         return ret;
1654 }
1655
1656 #ifdef CONFIG_SYSFS
1657 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
1658                 struct rx_queue_attribute *attribute, char *buf)
1659 {
1660         struct virtnet_info *vi = netdev_priv(queue->dev);
1661         unsigned int queue_index = get_netdev_rx_queue_index(queue);
1662         struct ewma_pkt_len *avg;
1663
1664         BUG_ON(queue_index >= vi->max_queue_pairs);
1665         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
1666         return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
1667 }
1668
1669 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
1670         __ATTR_RO(mergeable_rx_buffer_size);
1671
1672 static struct attribute *virtio_net_mrg_rx_attrs[] = {
1673         &mergeable_rx_buffer_size_attribute.attr,
1674         NULL
1675 };
1676
1677 static const struct attribute_group virtio_net_mrg_rx_group = {
1678         .name = "virtio_net",
1679         .attrs = virtio_net_mrg_rx_attrs
1680 };
1681 #endif
1682
1683 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
1684                                     unsigned int fbit,
1685                                     const char *fname, const char *dname)
1686 {
1687         if (!virtio_has_feature(vdev, fbit))
1688                 return false;
1689
1690         dev_err(&vdev->dev, "device advertises feature %s but not %s",
1691                 fname, dname);
1692
1693         return true;
1694 }
1695
1696 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)                       \
1697         virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
1698
1699 static bool virtnet_validate_features(struct virtio_device *vdev)
1700 {
1701         if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
1702             (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
1703                              "VIRTIO_NET_F_CTRL_VQ") ||
1704              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
1705                              "VIRTIO_NET_F_CTRL_VQ") ||
1706              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
1707                              "VIRTIO_NET_F_CTRL_VQ") ||
1708              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
1709              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
1710                              "VIRTIO_NET_F_CTRL_VQ"))) {
1711                 return false;
1712         }
1713
1714         return true;
1715 }
1716
1717 static int virtnet_probe(struct virtio_device *vdev)
1718 {
1719         int i, err;
1720         struct net_device *dev;
1721         struct virtnet_info *vi;
1722         u16 max_queue_pairs;
1723
1724         if (!vdev->config->get) {
1725                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
1726                         __func__);
1727                 return -EINVAL;
1728         }
1729
1730         if (!virtnet_validate_features(vdev))
1731                 return -EINVAL;
1732
1733         /* Find if host supports multiqueue virtio_net device */
1734         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
1735                                    struct virtio_net_config,
1736                                    max_virtqueue_pairs, &max_queue_pairs);
1737
1738         /* We need at least 2 queue's */
1739         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1740             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1741             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1742                 max_queue_pairs = 1;
1743
1744         /* Allocate ourselves a network device with room for our info */
1745         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1746         if (!dev)
1747                 return -ENOMEM;
1748
1749         /* Set up network device as normal. */
1750         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1751         dev->netdev_ops = &virtnet_netdev;
1752         dev->features = NETIF_F_HIGHDMA;
1753
1754         dev->ethtool_ops = &virtnet_ethtool_ops;
1755         SET_NETDEV_DEV(dev, &vdev->dev);
1756
1757         /* Do we support "hardware" checksums? */
1758         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1759                 /* This opens up the world of extra features. */
1760                 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
1761                 if (csum)
1762                         dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
1763
1764                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1765                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1766                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1767                 }
1768                 /* Individual feature bits: what can host handle? */
1769                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1770                         dev->hw_features |= NETIF_F_TSO;
1771                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1772                         dev->hw_features |= NETIF_F_TSO6;
1773                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1774                         dev->hw_features |= NETIF_F_TSO_ECN;
1775                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1776                         dev->hw_features |= NETIF_F_UFO;
1777
1778                 dev->features |= NETIF_F_GSO_ROBUST;
1779
1780                 if (gso)
1781                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1782                 /* (!csum && gso) case will be fixed by register_netdev() */
1783         }
1784         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
1785                 dev->features |= NETIF_F_RXCSUM;
1786
1787         dev->vlan_features = dev->features;
1788
1789         /* Configuration may specify what MAC to use.  Otherwise random. */
1790         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
1791                 virtio_cread_bytes(vdev,
1792                                    offsetof(struct virtio_net_config, mac),
1793                                    dev->dev_addr, dev->addr_len);
1794         else
1795                 eth_hw_addr_random(dev);
1796
1797         /* Set up our device-specific information */
1798         vi = netdev_priv(dev);
1799         vi->dev = dev;
1800         vi->vdev = vdev;
1801         vdev->priv = vi;
1802         vi->stats = alloc_percpu(struct virtnet_stats);
1803         err = -ENOMEM;
1804         if (vi->stats == NULL)
1805                 goto free;
1806
1807         for_each_possible_cpu(i) {
1808                 struct virtnet_stats *virtnet_stats;
1809                 virtnet_stats = per_cpu_ptr(vi->stats, i);
1810                 u64_stats_init(&virtnet_stats->tx_syncp);
1811                 u64_stats_init(&virtnet_stats->rx_syncp);
1812         }
1813
1814         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1815
1816         /* If we can receive ANY GSO packets, we must allocate large ones. */
1817         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1818             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1819             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
1820             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
1821                 vi->big_packets = true;
1822
1823         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1824                 vi->mergeable_rx_bufs = true;
1825
1826         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
1827             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
1828                 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1829         else
1830                 vi->hdr_len = sizeof(struct virtio_net_hdr);
1831
1832         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
1833             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
1834                 vi->any_header_sg = true;
1835
1836         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1837                 vi->has_cvq = true;
1838
1839         if (vi->any_header_sg)
1840                 dev->needed_headroom = vi->hdr_len;
1841
1842         /* Use single tx/rx queue pair as default */
1843         vi->curr_queue_pairs = 1;
1844         vi->max_queue_pairs = max_queue_pairs;
1845
1846         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1847         err = init_vqs(vi);
1848         if (err)
1849                 goto free_stats;
1850
1851 #ifdef CONFIG_SYSFS
1852         if (vi->mergeable_rx_bufs)
1853                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
1854 #endif
1855         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
1856         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
1857
1858         err = register_netdev(dev);
1859         if (err) {
1860                 pr_debug("virtio_net: registering device failed\n");
1861                 goto free_vqs;
1862         }
1863
1864         virtio_device_ready(vdev);
1865
1866         /* Last of all, set up some receive buffers. */
1867         for (i = 0; i < vi->curr_queue_pairs; i++) {
1868                 try_fill_recv(vi, &vi->rq[i], GFP_KERNEL);
1869
1870                 /* If we didn't even get one input buffer, we're useless. */
1871                 if (vi->rq[i].vq->num_free ==
1872                     virtqueue_get_vring_size(vi->rq[i].vq)) {
1873                         free_unused_bufs(vi);
1874                         err = -ENOMEM;
1875                         goto free_recv_bufs;
1876                 }
1877         }
1878
1879         vi->nb.notifier_call = &virtnet_cpu_callback;
1880         err = register_hotcpu_notifier(&vi->nb);
1881         if (err) {
1882                 pr_debug("virtio_net: registering cpu notifier failed\n");
1883                 goto free_recv_bufs;
1884         }
1885
1886         /* Assume link up if device can't report link status,
1887            otherwise get link status from config. */
1888         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1889                 netif_carrier_off(dev);
1890                 schedule_work(&vi->config_work);
1891         } else {
1892                 vi->status = VIRTIO_NET_S_LINK_UP;
1893                 netif_carrier_on(dev);
1894         }
1895
1896         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1897                  dev->name, max_queue_pairs);
1898
1899         return 0;
1900
1901 free_recv_bufs:
1902         vi->vdev->config->reset(vdev);
1903
1904         free_receive_bufs(vi);
1905         unregister_netdev(dev);
1906 free_vqs:
1907         cancel_delayed_work_sync(&vi->refill);
1908         free_receive_page_frags(vi);
1909         virtnet_del_vqs(vi);
1910 free_stats:
1911         free_percpu(vi->stats);
1912 free:
1913         free_netdev(dev);
1914         return err;
1915 }
1916
1917 static void remove_vq_common(struct virtnet_info *vi)
1918 {
1919         vi->vdev->config->reset(vi->vdev);
1920
1921         /* Free unused buffers in both send and recv, if any. */
1922         free_unused_bufs(vi);
1923
1924         free_receive_bufs(vi);
1925
1926         free_receive_page_frags(vi);
1927
1928         virtnet_del_vqs(vi);
1929 }
1930
1931 static void virtnet_remove(struct virtio_device *vdev)
1932 {
1933         struct virtnet_info *vi = vdev->priv;
1934
1935         unregister_hotcpu_notifier(&vi->nb);
1936
1937         /* Make sure no work handler is accessing the device. */
1938         flush_work(&vi->config_work);
1939
1940         unregister_netdev(vi->dev);
1941
1942         remove_vq_common(vi);
1943
1944         free_percpu(vi->stats);
1945         free_netdev(vi->dev);
1946 }
1947
1948 #ifdef CONFIG_PM_SLEEP
1949 static int virtnet_freeze(struct virtio_device *vdev)
1950 {
1951         struct virtnet_info *vi = vdev->priv;
1952         int i;
1953
1954         unregister_hotcpu_notifier(&vi->nb);
1955
1956         /* Make sure no work handler is accessing the device */
1957         flush_work(&vi->config_work);
1958
1959         netif_device_detach(vi->dev);
1960         cancel_delayed_work_sync(&vi->refill);
1961
1962         if (netif_running(vi->dev)) {
1963                 for (i = 0; i < vi->max_queue_pairs; i++)
1964                         napi_disable(&vi->rq[i].napi);
1965         }
1966
1967         remove_vq_common(vi);
1968
1969         return 0;
1970 }
1971
1972 static int virtnet_restore(struct virtio_device *vdev)
1973 {
1974         struct virtnet_info *vi = vdev->priv;
1975         int err, i;
1976
1977         err = init_vqs(vi);
1978         if (err)
1979                 return err;
1980
1981         virtio_device_ready(vdev);
1982
1983         if (netif_running(vi->dev)) {
1984                 for (i = 0; i < vi->curr_queue_pairs; i++)
1985                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1986                                 schedule_delayed_work(&vi->refill, 0);
1987
1988                 for (i = 0; i < vi->max_queue_pairs; i++)
1989                         virtnet_napi_enable(&vi->rq[i]);
1990         }
1991
1992         netif_device_attach(vi->dev);
1993
1994         rtnl_lock();
1995         virtnet_set_queues(vi, vi->curr_queue_pairs);
1996         rtnl_unlock();
1997
1998         err = register_hotcpu_notifier(&vi->nb);
1999         if (err)
2000                 return err;
2001
2002         return 0;
2003 }
2004 #endif
2005
2006 static struct virtio_device_id id_table[] = {
2007         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
2008         { 0 },
2009 };
2010
2011 static unsigned int features[] = {
2012         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
2013         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
2014         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
2015         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
2016         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
2017         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
2018         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
2019         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
2020         VIRTIO_NET_F_CTRL_MAC_ADDR,
2021         VIRTIO_F_ANY_LAYOUT,
2022 };
2023
2024 static struct virtio_driver virtio_net_driver = {
2025         .feature_table = features,
2026         .feature_table_size = ARRAY_SIZE(features),
2027         .driver.name =  KBUILD_MODNAME,
2028         .driver.owner = THIS_MODULE,
2029         .id_table =     id_table,
2030         .probe =        virtnet_probe,
2031         .remove =       virtnet_remove,
2032         .config_changed = virtnet_config_changed,
2033 #ifdef CONFIG_PM_SLEEP
2034         .freeze =       virtnet_freeze,
2035         .restore =      virtnet_restore,
2036 #endif
2037 };
2038
2039 module_virtio_driver(virtio_net_driver);
2040
2041 MODULE_DEVICE_TABLE(virtio, id_table);
2042 MODULE_DESCRIPTION("Virtio network driver");
2043 MODULE_LICENSE("GPL");