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         struct virtio_net_ctrl_mq ctrl_mq;
 148         u8 ctrl_promisc;
 149         u8 ctrl_allmulti;
 150         u16 ctrl_vid;
 151
 152         /* Ethtool settings */
 153         u8 duplex;
 154         u32 speed;
 155 };
 156
 157 struct padded_vnet_hdr {
 158         struct virtio_net_hdr_mrg_rxbuf hdr;
 159         /*
 160          * hdr is in a separate sg buffer, and data sg buffer shares same page
 161          * with this header sg. This padding makes next sg 16 byte aligned
 162          * after the header.
 163          */
 164         char padding[4];
 165 };
 166
 167 /* Converting between virtqueue no. and kernel tx/rx queue no.
 168  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 169  */
 170 static int vq2txq(struct virtqueue *vq)
 171 {
 172         return (vq->index - 1) / 2;
 173 }
 174
 175 static int txq2vq(int txq)
 176 {
 177         return txq * 2 + 1;
 178 }
 179
 180 static int vq2rxq(struct virtqueue *vq)
 181 {
 182         return vq->index / 2;
 183 }
 184
 185 static int rxq2vq(int rxq)
 186 {
 187         return rxq * 2;
 188 }
 189
 190 static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 191 {
 192         return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
 193 }
 194
 195 /*
 196  * private is used to chain pages for big packets, put the whole
 197  * most recent used list in the beginning for reuse
 198  */
 199 static void give_pages(struct receive_queue *rq, struct page *page)
 200 {
 201         struct page *end;
 202
 203         /* Find end of list, sew whole thing into vi->rq.pages. */
 204         for (end = page; end->private; end = (struct page *)end->private);
 205         end->private = (unsigned long)rq->pages;
 206         rq->pages = page;
 207 }
 208
 209 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 210 {
 211         struct page *p = rq->pages;
 212
 213         if (p) {
 214                 rq->pages = (struct page *)p->private;
 215                 /* clear private here, it is used to chain pages */
 216                 p->private = 0;
 217         } else
 218                 p = alloc_page(gfp_mask);
 219         return p;
 220 }
 221
 222 static void skb_xmit_done(struct virtqueue *vq)
 223 {
 224         struct virtnet_info *vi = vq->vdev->priv;
 225
 226         /* Suppress further interrupts. */
 227         virtqueue_disable_cb(vq);
 228
 229         /* We were probably waiting for more output buffers. */
 230         netif_wake_subqueue(vi->dev, vq2txq(vq));
 231 }
 232
 233 static unsigned int mergeable_ctx_to_buf_truesize(unsigned long mrg_ctx)
 234 {
 235         unsigned int truesize = mrg_ctx & (MERGEABLE_BUFFER_ALIGN - 1);
 236         return (truesize + 1) * MERGEABLE_BUFFER_ALIGN;
 237 }
 238
 239 static void *mergeable_ctx_to_buf_address(unsigned long mrg_ctx)
 240 {
 241         return (void *)(mrg_ctx & -MERGEABLE_BUFFER_ALIGN);
 242
 243 }
 244
 245 static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize)
 246 {
 247         unsigned int size = truesize / MERGEABLE_BUFFER_ALIGN;
 248         return (unsigned long)buf | (size - 1);
 249 }
 250
 251 /* Called from bottom half context */
 252 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 253                                    struct receive_queue *rq,
 254                                    struct page *page, unsigned int offset,
 255                                    unsigned int len, unsigned int truesize)
 256 {
 257         struct sk_buff *skb;
 258         struct virtio_net_hdr_mrg_rxbuf *hdr;
 259         unsigned int copy, hdr_len, hdr_padded_len;
 260         char *p;
 261
 262         p = page_address(page) + offset;
 263
 264         /* copy small packet so we can reuse these pages for small data */
 265         skb = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
 266         if (unlikely(!skb))
 267                 return NULL;
 268
 269         hdr = skb_vnet_hdr(skb);
 270
 271         hdr_len = vi->hdr_len;
 272         if (vi->mergeable_rx_bufs)
 273                 hdr_padded_len = sizeof *hdr;
 274         else
 275                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 276
 277         memcpy(hdr, p, hdr_len);
 278
 279         len -= hdr_len;
 280         offset += hdr_padded_len;
 281         p += hdr_padded_len;
 282
 283         copy = len;
 284         if (copy > skb_tailroom(skb))
 285                 copy = skb_tailroom(skb);
 286         memcpy(skb_put(skb, copy), p, copy);
 287
 288         len -= copy;
 289         offset += copy;
 290
 291         if (vi->mergeable_rx_bufs) {
 292                 if (len)
 293                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 294                 else
 295                         put_page(page);
 296                 return skb;
 297         }
 298
 299         /*
 300          * Verify that we can indeed put this data into a skb.
 301          * This is here to handle cases when the device erroneously
 302          * tries to receive more than is possible. This is usually
 303          * the case of a broken device.
 304          */
 305         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 306                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 307                 dev_kfree_skb(skb);
 308                 return NULL;
 309         }
 310         BUG_ON(offset >= PAGE_SIZE);
 311         while (len) {
 312                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 313                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 314                                 frag_size, truesize);
 315                 len -= frag_size;
 316                 page = (struct page *)page->private;
 317                 offset = 0;
 318         }
 319
 320         if (page)
 321                 give_pages(rq, page);
 322
 323         return skb;
 324 }
 325
 326 static struct sk_buff *receive_small(struct virtnet_info *vi, void *buf, unsigned int len)
 327 {
 328         struct sk_buff * skb = buf;
 329
 330         len -= vi->hdr_len;
 331         skb_trim(skb, len);
 332
 333         return skb;
 334 }
 335
 336 static struct sk_buff *receive_big(struct net_device *dev,
 337                                    struct virtnet_info *vi,
 338                                    struct receive_queue *rq,
 339                                    void *buf,
 340                                    unsigned int len)
 341 {
 342         struct page *page = buf;
 343         struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
 344
 345         if (unlikely(!skb))
 346                 goto err;
 347
 348         return skb;
 349
 350 err:
 351         dev->stats.rx_dropped++;
 352         give_pages(rq, page);
 353         return NULL;
 354 }
 355
 356 static struct sk_buff *receive_mergeable(struct net_device *dev,
 357                                          struct virtnet_info *vi,
 358                                          struct receive_queue *rq,
 359                                          unsigned long ctx,
 360                                          unsigned int len)
 361 {
 362         void *buf = mergeable_ctx_to_buf_address(ctx);
 363         struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
 364         u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
 365         struct page *page = virt_to_head_page(buf);
 366         int offset = buf - page_address(page);
 367         unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 368
 369         struct sk_buff *head_skb = page_to_skb(vi, rq, page, offset, len,
 370                                                truesize);
 371         struct sk_buff *curr_skb = head_skb;
 372
 373         if (unlikely(!curr_skb))
 374                 goto err_skb;
 375         while (--num_buf) {
 376                 int num_skb_frags;
 377
 378                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 379                 if (unlikely(!ctx)) {
 380                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
 381                                  dev->name, num_buf,
 382                                  virtio16_to_cpu(vi->vdev,
 383                                                  hdr->num_buffers));
 384                         dev->stats.rx_length_errors++;
 385                         goto err_buf;
 386                 }
 387
 388                 buf = mergeable_ctx_to_buf_address(ctx);
 389                 page = virt_to_head_page(buf);
 390
 391                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
 392                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
 393                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
 394
 395                         if (unlikely(!nskb))
 396                                 goto err_skb;
 397                         if (curr_skb == head_skb)
 398                                 skb_shinfo(curr_skb)->frag_list = nskb;
 399                         else
 400                                 curr_skb->next = nskb;
 401                         curr_skb = nskb;
 402                         head_skb->truesize += nskb->truesize;
 403                         num_skb_frags = 0;
 404                 }
 405                 truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 406                 if (curr_skb != head_skb) {
 407                         head_skb->data_len += len;
 408                         head_skb->len += len;
 409                         head_skb->truesize += truesize;
 410                 }
 411                 offset = buf - page_address(page);
 412                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
 413                         put_page(page);
 414                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
 415                                              len, truesize);
 416                 } else {
 417                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
 418                                         offset, len, truesize);
 419                 }
 420         }
 421
 422         ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
 423         return head_skb;
 424
 425 err_skb:
 426         put_page(page);
 427         while (--num_buf) {
 428                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 429                 if (unlikely(!ctx)) {
 430                         pr_debug("%s: rx error: %d buffers missing\n",
 431                                  dev->name, num_buf);
 432                         dev->stats.rx_length_errors++;
 433                         break;
 434                 }
 435                 page = virt_to_head_page(mergeable_ctx_to_buf_address(ctx));
 436                 put_page(page);
 437         }
 438 err_buf:
 439         dev->stats.rx_dropped++;
 440         dev_kfree_skb(head_skb);
 441         return NULL;
 442 }
 443
 444 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 445                         void *buf, unsigned int len)
 446 {
 447         struct net_device *dev = vi->dev;
 448         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 449         struct sk_buff *skb;
 450         struct virtio_net_hdr_mrg_rxbuf *hdr;
 451
 452         if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
 453                 pr_debug("%s: short packet %i\n", dev->name, len);
 454                 dev->stats.rx_length_errors++;
 455                 if (vi->mergeable_rx_bufs) {
 456                         unsigned long ctx = (unsigned long)buf;
 457                         void *base = mergeable_ctx_to_buf_address(ctx);
 458                         put_page(virt_to_head_page(base));
 459                 } else if (vi->big_packets) {
 460                         give_pages(rq, buf);
 461                 } else {
 462                         dev_kfree_skb(buf);
 463                 }
 464                 return;
 465         }
 466
 467         if (vi->mergeable_rx_bufs)
 468                 skb = receive_mergeable(dev, vi, rq, (unsigned long)buf, len);
 469         else if (vi->big_packets)
 470                 skb = receive_big(dev, vi, rq, buf, len);
 471         else
 472                 skb = receive_small(vi, buf, len);
 473
 474         if (unlikely(!skb))
 475                 return;
 476
 477         hdr = skb_vnet_hdr(skb);
 478
 479         u64_stats_update_begin(&stats->rx_syncp);
 480         stats->rx_bytes += skb->len;
 481         stats->rx_packets++;
 482         u64_stats_update_end(&stats->rx_syncp);
 483
 484         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
 485                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 486
 487         if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
 488                                   virtio_is_little_endian(vi->vdev))) {
 489                 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
 490                                      dev->name, hdr->hdr.gso_type,
 491                                      hdr->hdr.gso_size);
 492                 goto frame_err;
 493         }
 494
 495         skb->protocol = eth_type_trans(skb, dev);
 496         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 497                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 498
 499         napi_gro_receive(&rq->napi, skb);
 500         return;
 501
 502 frame_err:
 503         dev->stats.rx_frame_errors++;
 504         dev_kfree_skb(skb);
 505 }
 506
 507 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 508                              gfp_t gfp)
 509 {
 510         struct sk_buff *skb;
 511         struct virtio_net_hdr_mrg_rxbuf *hdr;
 512         int err;
 513
 514         skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
 515         if (unlikely(!skb))
 516                 return -ENOMEM;
 517
 518         skb_put(skb, GOOD_PACKET_LEN);
 519
 520         hdr = skb_vnet_hdr(skb);
 521         sg_init_table(rq->sg, 2);
 522         sg_set_buf(rq->sg, hdr, vi->hdr_len);
 523         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 524
 525         err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
 526         if (err < 0)
 527                 dev_kfree_skb(skb);
 528
 529         return err;
 530 }
 531
 532 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
 533                            gfp_t gfp)
 534 {
 535         struct page *first, *list = NULL;
 536         char *p;
 537         int i, err, offset;
 538
 539         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
 540
 541         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 542         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 543                 first = get_a_page(rq, gfp);
 544                 if (!first) {
 545                         if (list)
 546                                 give_pages(rq, list);
 547                         return -ENOMEM;
 548                 }
 549                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
 550
 551                 /* chain new page in list head to match sg */
 552                 first->private = (unsigned long)list;
 553                 list = first;
 554         }
 555
 556         first = get_a_page(rq, gfp);
 557         if (!first) {
 558                 give_pages(rq, list);
 559                 return -ENOMEM;
 560         }
 561         p = page_address(first);
 562
 563         /* rq->sg[0], rq->sg[1] share the same page */
 564         /* a separated rq->sg[0] for header - required in case !any_header_sg */
 565         sg_set_buf(&rq->sg[0], p, vi->hdr_len);
 566
 567         /* rq->sg[1] for data packet, from offset */
 568         offset = sizeof(struct padded_vnet_hdr);
 569         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
 570
 571         /* chain first in list head */
 572         first->private = (unsigned long)list;
 573         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
 574                                   first, gfp);
 575         if (err < 0)
 576                 give_pages(rq, first);
 577
 578         return err;
 579 }
 580
 581 static unsigned int get_mergeable_buf_len(struct ewma_pkt_len *avg_pkt_len)
 582 {
 583         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 584         unsigned int len;
 585
 586         len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
 587                         GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
 588         return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
 589 }
 590
 591 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
 592 {
 593         struct page_frag *alloc_frag = &rq->alloc_frag;
 594         char *buf;
 595         unsigned long ctx;
 596         int err;
 597         unsigned int len, hole;
 598
 599         len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
 600         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
 601                 return -ENOMEM;
 602
 603         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
 604         ctx = mergeable_buf_to_ctx(buf, len);
 605         get_page(alloc_frag->page);
 606         alloc_frag->offset += len;
 607         hole = alloc_frag->size - alloc_frag->offset;
 608         if (hole < len) {
 609                 /* To avoid internal fragmentation, if there is very likely not
 610                  * enough space for another buffer, add the remaining space to
 611                  * the current buffer. This extra space is not included in
 612                  * the truesize stored in ctx.
 613                  */
 614                 len += hole;
 615                 alloc_frag->offset += hole;
 616         }
 617
 618         sg_init_one(rq->sg, buf, len);
 619         err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
 620         if (err < 0)
 621                 put_page(virt_to_head_page(buf));
 622
 623         return err;
 624 }
 625
 626 /*
 627  * Returns false if we couldn't fill entirely (OOM).
 628  *
 629  * Normally run in the receive path, but can also be run from ndo_open
 630  * before we're receiving packets, or from refill_work which is
 631  * careful to disable receiving (using napi_disable).
 632  */
 633 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
 634                           gfp_t gfp)
 635 {
 636         int err;
 637         bool oom;
 638
 639         gfp |= __GFP_COLD;
 640         do {
 641                 if (vi->mergeable_rx_bufs)
 642                         err = add_recvbuf_mergeable(rq, gfp);
 643                 else if (vi->big_packets)
 644                         err = add_recvbuf_big(vi, rq, gfp);
 645                 else
 646                         err = add_recvbuf_small(vi, rq, gfp);
 647
 648                 oom = err == -ENOMEM;
 649                 if (err)
 650                         break;
 651         } while (rq->vq->num_free);
 652         virtqueue_kick(rq->vq);
 653         return !oom;
 654 }
 655
 656 static void skb_recv_done(struct virtqueue *rvq)
 657 {
 658         struct virtnet_info *vi = rvq->vdev->priv;
 659         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 660
 661         /* Schedule NAPI, Suppress further interrupts if successful. */
 662         if (napi_schedule_prep(&rq->napi)) {
 663                 virtqueue_disable_cb(rvq);
 664                 __napi_schedule(&rq->napi);
 665         }
 666 }
 667
 668 static void virtnet_napi_enable(struct receive_queue *rq)
 669 {
 670         napi_enable(&rq->napi);
 671
 672         /* If all buffers were filled by other side before we napi_enabled, we
 673          * won't get another interrupt, so process any outstanding packets
 674          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 675          * We synchronize against interrupts via NAPI_STATE_SCHED */
 676         if (napi_schedule_prep(&rq->napi)) {
 677                 virtqueue_disable_cb(rq->vq);
 678                 local_bh_disable();
 679                 __napi_schedule(&rq->napi);
 680                 local_bh_enable();
 681         }
 682 }
 683
 684 static void refill_work(struct work_struct *work)
 685 {
 686         struct virtnet_info *vi =
 687                 container_of(work, struct virtnet_info, refill.work);
 688         bool still_empty;
 689         int i;
 690
 691         for (i = 0; i < vi->curr_queue_pairs; i++) {
 692                 struct receive_queue *rq = &vi->rq[i];
 693
 694                 napi_disable(&rq->napi);
 695                 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
 696                 virtnet_napi_enable(rq);
 697
 698                 /* In theory, this can happen: if we don't get any buffers in
 699                  * we will *never* try to fill again.
 700                  */
 701                 if (still_empty)
 702                         schedule_delayed_work(&vi->refill, HZ/2);
 703         }
 704 }
 705
 706 static int virtnet_receive(struct receive_queue *rq, int budget)
 707 {
 708         struct virtnet_info *vi = rq->vq->vdev->priv;
 709         unsigned int len, received = 0;
 710         void *buf;
 711
 712         while (received < budget &&
 713                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
 714                 receive_buf(vi, rq, buf, len);
 715                 received++;
 716         }
 717
 718         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
 719                 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
 720                         schedule_delayed_work(&vi->refill, 0);
 721         }
 722
 723         return received;
 724 }
 725
 726 static int virtnet_poll(struct napi_struct *napi, int budget)
 727 {
 728         struct receive_queue *rq =
 729                 container_of(napi, struct receive_queue, napi);
 730         unsigned int r, received;
 731
 732         received = virtnet_receive(rq, budget);
 733
 734         /* Out of packets? */
 735         if (received < budget) {
 736                 r = virtqueue_enable_cb_prepare(rq->vq);
 737                 napi_complete_done(napi, received);
 738                 if (unlikely(virtqueue_poll(rq->vq, r)) &&
 739                     napi_schedule_prep(napi)) {
 740                         virtqueue_disable_cb(rq->vq);
 741                         __napi_schedule(napi);
 742                 }
 743         }
 744
 745         return received;
 746 }
 747
 748 #ifdef CONFIG_NET_RX_BUSY_POLL
 749 /* must be called with local_bh_disable()d */
 750 static int virtnet_busy_poll(struct napi_struct *napi)
 751 {
 752         struct receive_queue *rq =
 753                 container_of(napi, struct receive_queue, napi);
 754         struct virtnet_info *vi = rq->vq->vdev->priv;
 755         int r, received = 0, budget = 4;
 756
 757         if (!(vi->status & VIRTIO_NET_S_LINK_UP))
 758                 return LL_FLUSH_FAILED;
 759
 760         if (!napi_schedule_prep(napi))
 761                 return LL_FLUSH_BUSY;
 762
 763         virtqueue_disable_cb(rq->vq);
 764
 765 again:
 766         received += virtnet_receive(rq, budget);
 767
 768         r = virtqueue_enable_cb_prepare(rq->vq);
 769         clear_bit(NAPI_STATE_SCHED, &napi->state);
 770         if (unlikely(virtqueue_poll(rq->vq, r)) &&
 771             napi_schedule_prep(napi)) {
 772                 virtqueue_disable_cb(rq->vq);
 773                 if (received < budget) {
 774                         budget -= received;
 775                         goto again;
 776                 } else {
 777                         __napi_schedule(napi);
 778                 }
 779         }
 780
 781         return received;
 782 }
 783 #endif  /* CONFIG_NET_RX_BUSY_POLL */
 784
 785 static int virtnet_open(struct net_device *dev)
 786 {
 787         struct virtnet_info *vi = netdev_priv(dev);
 788         int i;
 789
 790         for (i = 0; i < vi->max_queue_pairs; i++) {
 791                 if (i < vi->curr_queue_pairs)
 792                         /* Make sure we have some buffers: if oom use wq. */
 793                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
 794                                 schedule_delayed_work(&vi->refill, 0);
 795                 virtnet_napi_enable(&vi->rq[i]);
 796         }
 797
 798         return 0;
 799 }
 800
 801 static void free_old_xmit_skbs(struct send_queue *sq)
 802 {
 803         struct sk_buff *skb;
 804         unsigned int len;
 805         struct virtnet_info *vi = sq->vq->vdev->priv;
 806         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 807
 808         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 809                 pr_debug("Sent skb %p\n", skb);
 810
 811                 u64_stats_update_begin(&stats->tx_syncp);
 812                 stats->tx_bytes += skb->len;
 813                 stats->tx_packets++;
 814                 u64_stats_update_end(&stats->tx_syncp);
 815
 816                 dev_kfree_skb_any(skb);
 817         }
 818 }
 819
 820 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 821 {
 822         struct virtio_net_hdr_mrg_rxbuf *hdr;
 823         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 824         struct virtnet_info *vi = sq->vq->vdev->priv;
 825         unsigned num_sg;
 826         unsigned hdr_len = vi->hdr_len;
 827         bool can_push;
 828
 829         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 830
 831         can_push = vi->any_header_sg &&
 832                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
 833                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
 834         /* Even if we can, don't push here yet as this would skew
 835          * csum_start offset below. */
 836         if (can_push)
 837                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
 838         else
 839                 hdr = skb_vnet_hdr(skb);
 840
 841         if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
 842                                     virtio_is_little_endian(vi->vdev)))
 843                 BUG();
 844
 845         if (vi->mergeable_rx_bufs)
 846                 hdr->num_buffers = 0;
 847
 848         sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
 849         if (can_push) {
 850                 __skb_push(skb, hdr_len);
 851                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
 852                 /* Pull header back to avoid skew in tx bytes calculations. */
 853                 __skb_pull(skb, hdr_len);
 854         } else {
 855                 sg_set_buf(sq->sg, hdr, hdr_len);
 856                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
 857         }
 858         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
 859 }
 860
 861 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 862 {
 863         struct virtnet_info *vi = netdev_priv(dev);
 864         int qnum = skb_get_queue_mapping(skb);
 865         struct send_queue *sq = &vi->sq[qnum];
 866         int err;
 867         struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
 868         bool kick = !skb->xmit_more;
 869
 870         /* Free up any pending old buffers before queueing new ones. */
 871         free_old_xmit_skbs(sq);
 872
 873         /* timestamp packet in software */
 874         skb_tx_timestamp(skb);
 875
 876         /* Try to transmit */
 877         err = xmit_skb(sq, skb);
 878
 879         /* This should not happen! */
 880         if (unlikely(err)) {
 881                 dev->stats.tx_fifo_errors++;
 882                 if (net_ratelimit())
 883                         dev_warn(&dev->dev,
 884                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
 885                 dev->stats.tx_dropped++;
 886                 dev_kfree_skb_any(skb);
 887                 return NETDEV_TX_OK;
 888         }
 889
 890         /* Don't wait up for transmitted skbs to be freed. */
 891         skb_orphan(skb);
 892         nf_reset(skb);
 893
 894         /* If running out of space, stop queue to avoid getting packets that we
 895          * are then unable to transmit.
 896          * An alternative would be to force queuing layer to requeue the skb by
 897          * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
 898          * returned in a normal path of operation: it means that driver is not
 899          * maintaining the TX queue stop/start state properly, and causes
 900          * the stack to do a non-trivial amount of useless work.
 901          * Since most packets only take 1 or 2 ring slots, stopping the queue
 902          * early means 16 slots are typically wasted.
 903          */
 904         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
 905                 netif_stop_subqueue(dev, qnum);
 906                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 907                         /* More just got used, free them then recheck. */
 908                         free_old_xmit_skbs(sq);
 909                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
 910                                 netif_start_subqueue(dev, qnum);
 911                                 virtqueue_disable_cb(sq->vq);
 912                         }
 913                 }
 914         }
 915
 916         if (kick || netif_xmit_stopped(txq))
 917                 virtqueue_kick(sq->vq);
 918
 919         return NETDEV_TX_OK;
 920 }
 921
 922 /*
 923  * Send command via the control virtqueue and check status.  Commands
 924  * supported by the hypervisor, as indicated by feature bits, should
 925  * never fail unless improperly formatted.
 926  */
 927 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 928                                  struct scatterlist *out)
 929 {
 930         struct scatterlist *sgs[4], hdr, stat;
 931         unsigned out_num = 0, tmp;
 932
 933         /* Caller should know better */
 934         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
 935
 936         vi->ctrl_status = ~0;
 937         vi->ctrl_hdr.class = class;
 938         vi->ctrl_hdr.cmd = cmd;
 939         /* Add header */
 940         sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr));
 941         sgs[out_num++] = &hdr;
 942
 943         if (out)
 944                 sgs[out_num++] = out;
 945
 946         /* Add return status. */
 947         sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status));
 948         sgs[out_num] = &stat;
 949
 950         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
 951         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
 952
 953         if (unlikely(!virtqueue_kick(vi->cvq)))
 954                 return vi->ctrl_status == VIRTIO_NET_OK;
 955
 956         /* Spin for a response, the kick causes an ioport write, trapping
 957          * into the hypervisor, so the request should be handled immediately.
 958          */
 959         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
 960                !virtqueue_is_broken(vi->cvq))
 961                 cpu_relax();
 962
 963         return vi->ctrl_status == VIRTIO_NET_OK;
 964 }
 965
 966 static int virtnet_set_mac_address(struct net_device *dev, void *p)
 967 {
 968         struct virtnet_info *vi = netdev_priv(dev);
 969         struct virtio_device *vdev = vi->vdev;
 970         int ret;
 971         struct sockaddr *addr = p;
 972         struct scatterlist sg;
 973
 974         ret = eth_prepare_mac_addr_change(dev, p);
 975         if (ret)
 976                 return ret;
 977
 978         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
 979                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
 980                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
 981                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
 982                         dev_warn(&vdev->dev,
 983                                  "Failed to set mac address by vq command.\n");
 984                         return -EINVAL;
 985                 }
 986         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
 987                    !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
 988                 unsigned int i;
 989
 990                 /* Naturally, this has an atomicity problem. */
 991                 for (i = 0; i < dev->addr_len; i++)
 992                         virtio_cwrite8(vdev,
 993                                        offsetof(struct virtio_net_config, mac) +
 994                                        i, addr->sa_data[i]);
 995         }
 996
 997         eth_commit_mac_addr_change(dev, p);
 998
 999         return 0;
1000 }
1001
1002 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
1003                                                struct rtnl_link_stats64 *tot)
1004 {
1005         struct virtnet_info *vi = netdev_priv(dev);
1006         int cpu;
1007         unsigned int start;
1008
1009         for_each_possible_cpu(cpu) {
1010                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1011                 u64 tpackets, tbytes, rpackets, rbytes;
1012
1013                 do {
1014                         start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
1015                         tpackets = stats->tx_packets;
1016                         tbytes   = stats->tx_bytes;
1017                 } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
1018
1019                 do {
1020                         start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
1021                         rpackets = stats->rx_packets;
1022                         rbytes   = stats->rx_bytes;
1023                 } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
1024
1025                 tot->rx_packets += rpackets;
1026                 tot->tx_packets += tpackets;
1027                 tot->rx_bytes   += rbytes;
1028                 tot->tx_bytes   += tbytes;
1029         }
1030
1031         tot->tx_dropped = dev->stats.tx_dropped;
1032         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1033         tot->rx_dropped = dev->stats.rx_dropped;
1034         tot->rx_length_errors = dev->stats.rx_length_errors;
1035         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1036
1037         return tot;
1038 }
1039
1040 #ifdef CONFIG_NET_POLL_CONTROLLER
1041 static void virtnet_netpoll(struct net_device *dev)
1042 {
1043         struct virtnet_info *vi = netdev_priv(dev);
1044         int i;
1045
1046         for (i = 0; i < vi->curr_queue_pairs; i++)
1047                 napi_schedule(&vi->rq[i].napi);
1048 }
1049 #endif
1050
1051 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1052 {
1053         rtnl_lock();
1054         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1055                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1056                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1057         rtnl_unlock();
1058 }
1059
1060 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1061 {
1062         struct scatterlist sg;
1063         struct net_device *dev = vi->dev;
1064
1065         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1066                 return 0;
1067
1068         vi->ctrl_mq.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1069         sg_init_one(&sg, &vi->ctrl_mq, sizeof(vi->ctrl_mq));
1070
1071         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1072                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1073                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1074                          queue_pairs);
1075                 return -EINVAL;
1076         } else {
1077                 vi->curr_queue_pairs = queue_pairs;
1078                 /* virtnet_open() will refill when device is going to up. */
1079                 if (dev->flags & IFF_UP)
1080                         schedule_delayed_work(&vi->refill, 0);
1081         }
1082
1083         return 0;
1084 }
1085
1086 static int virtnet_close(struct net_device *dev)
1087 {
1088         struct virtnet_info *vi = netdev_priv(dev);
1089         int i;
1090
1091         /* Make sure refill_work doesn't re-enable napi! */
1092         cancel_delayed_work_sync(&vi->refill);
1093
1094         for (i = 0; i < vi->max_queue_pairs; i++)
1095                 napi_disable(&vi->rq[i].napi);
1096
1097         return 0;
1098 }
1099
1100 static void virtnet_set_rx_mode(struct net_device *dev)
1101 {
1102         struct virtnet_info *vi = netdev_priv(dev);
1103         struct scatterlist sg[2];
1104         struct virtio_net_ctrl_mac *mac_data;
1105         struct netdev_hw_addr *ha;
1106         int uc_count;
1107         int mc_count;
1108         void *buf;
1109         int i;
1110
1111         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1112         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1113                 return;
1114
1115         vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0);
1116         vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1117
1118         sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc));
1119
1120         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1121                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1122                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1123                          vi->ctrl_promisc ? "en" : "dis");
1124
1125         sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti));
1126
1127         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1128                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1129                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1130                          vi->ctrl_allmulti ? "en" : "dis");
1131
1132         uc_count = netdev_uc_count(dev);
1133         mc_count = netdev_mc_count(dev);
1134         /* MAC filter - use one buffer for both lists */
1135         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1136                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1137         mac_data = buf;
1138         if (!buf)
1139                 return;
1140
1141         sg_init_table(sg, 2);
1142
1143         /* Store the unicast list and count in the front of the buffer */
1144         mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1145         i = 0;
1146         netdev_for_each_uc_addr(ha, dev)
1147                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1148
1149         sg_set_buf(&sg[0], mac_data,
1150                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1151
1152         /* multicast list and count fill the end */
1153         mac_data = (void *)&mac_data->macs[uc_count][0];
1154
1155         mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1156         i = 0;
1157         netdev_for_each_mc_addr(ha, dev)
1158                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1159
1160         sg_set_buf(&sg[1], mac_data,
1161                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1162
1163         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1164                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1165                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1166
1167         kfree(buf);
1168 }
1169
1170 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1171                                    __be16 proto, u16 vid)
1172 {
1173         struct virtnet_info *vi = netdev_priv(dev);
1174         struct scatterlist sg;
1175
1176         vi->ctrl_vid = vid;
1177         sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid));
1178
1179         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1180                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1181                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1182         return 0;
1183 }
1184
1185 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1186                                     __be16 proto, u16 vid)
1187 {
1188         struct virtnet_info *vi = netdev_priv(dev);
1189         struct scatterlist sg;
1190
1191         vi->ctrl_vid = vid;
1192         sg_init_one(&sg, &vi->ctrl_vid, sizeof(vi->ctrl_vid));
1193
1194         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1195                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1196                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1197         return 0;
1198 }
1199
1200 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1201 {
1202         int i;
1203
1204         if (vi->affinity_hint_set) {
1205                 for (i = 0; i < vi->max_queue_pairs; i++) {
1206                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1207                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1208                 }
1209
1210                 vi->affinity_hint_set = false;
1211         }
1212 }
1213
1214 static void virtnet_set_affinity(struct virtnet_info *vi)
1215 {
1216         int i;
1217         int cpu;
1218
1219         /* In multiqueue mode, when the number of cpu is equal to the number of
1220          * queue pairs, we let the queue pairs to be private to one cpu by
1221          * setting the affinity hint to eliminate the contention.
1222          */
1223         if (vi->curr_queue_pairs == 1 ||
1224             vi->max_queue_pairs != num_online_cpus()) {
1225                 virtnet_clean_affinity(vi, -1);
1226                 return;
1227         }
1228
1229         i = 0;
1230         for_each_online_cpu(cpu) {
1231                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1232                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1233                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1234                 i++;
1235         }
1236
1237         vi->affinity_hint_set = true;
1238 }
1239
1240 static int virtnet_cpu_callback(struct notifier_block *nfb,
1241                                 unsigned long action, void *hcpu)
1242 {
1243         struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);
1244
1245         switch(action & ~CPU_TASKS_FROZEN) {
1246         case CPU_ONLINE:
1247         case CPU_DOWN_FAILED:
1248         case CPU_DEAD:
1249                 virtnet_set_affinity(vi);
1250                 break;
1251         case CPU_DOWN_PREPARE:
1252                 virtnet_clean_affinity(vi, (long)hcpu);
1253                 break;
1254         default:
1255                 break;
1256         }
1257
1258         return NOTIFY_OK;
1259 }
1260
1261 static void virtnet_get_ringparam(struct net_device *dev,
1262                                 struct ethtool_ringparam *ring)
1263 {
1264         struct virtnet_info *vi = netdev_priv(dev);
1265
1266         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1267         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1268         ring->rx_pending = ring->rx_max_pending;
1269         ring->tx_pending = ring->tx_max_pending;
1270 }
1271
1272
1273 static void virtnet_get_drvinfo(struct net_device *dev,
1274                                 struct ethtool_drvinfo *info)
1275 {
1276         struct virtnet_info *vi = netdev_priv(dev);
1277         struct virtio_device *vdev = vi->vdev;
1278
1279         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1280         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1281         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1282
1283 }
1284
1285 /* TODO: Eliminate OOO packets during switching */
1286 static int virtnet_set_channels(struct net_device *dev,
1287                                 struct ethtool_channels *channels)
1288 {
1289         struct virtnet_info *vi = netdev_priv(dev);
1290         u16 queue_pairs = channels->combined_count;
1291         int err;
1292
1293         /* We don't support separate rx/tx channels.
1294          * We don't allow setting 'other' channels.
1295          */
1296         if (channels->rx_count || channels->tx_count || channels->other_count)
1297                 return -EINVAL;
1298
1299         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1300                 return -EINVAL;
1301
1302         get_online_cpus();
1303         err = virtnet_set_queues(vi, queue_pairs);
1304         if (!err) {
1305                 netif_set_real_num_tx_queues(dev, queue_pairs);
1306                 netif_set_real_num_rx_queues(dev, queue_pairs);
1307
1308                 virtnet_set_affinity(vi);
1309         }
1310         put_online_cpus();
1311
1312         return err;
1313 }
1314
1315 static void virtnet_get_channels(struct net_device *dev,
1316                                  struct ethtool_channels *channels)
1317 {
1318         struct virtnet_info *vi = netdev_priv(dev);
1319
1320         channels->combined_count = vi->curr_queue_pairs;
1321         channels->max_combined = vi->max_queue_pairs;
1322         channels->max_other = 0;
1323         channels->rx_count = 0;
1324         channels->tx_count = 0;
1325         channels->other_count = 0;
1326 }
1327
1328 /* Check if the user is trying to change anything besides speed/duplex */
1329 static bool virtnet_validate_ethtool_cmd(const struct ethtool_cmd *cmd)
1330 {
1331         struct ethtool_cmd diff1 = *cmd;
1332         struct ethtool_cmd diff2 = {};
1333
1334         /* cmd is always set so we need to clear it, validate the port type
1335          * and also without autonegotiation we can ignore advertising
1336          */
1337         ethtool_cmd_speed_set(&diff1, 0);
1338         diff2.port = PORT_OTHER;
1339         diff1.advertising = 0;
1340         diff1.duplex = 0;
1341         diff1.cmd = 0;
1342
1343         return !memcmp(&diff1, &diff2, sizeof(diff1));
1344 }
1345
1346 static int virtnet_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1347 {
1348         struct virtnet_info *vi = netdev_priv(dev);
1349         u32 speed;
1350
1351         speed = ethtool_cmd_speed(cmd);
1352         /* don't allow custom speed and duplex */
1353         if (!ethtool_validate_speed(speed) ||
1354             !ethtool_validate_duplex(cmd->duplex) ||
1355             !virtnet_validate_ethtool_cmd(cmd))
1356                 return -EINVAL;
1357         vi->speed = speed;
1358         vi->duplex = cmd->duplex;
1359
1360         return 0;
1361 }
1362
1363 static int virtnet_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1364 {
1365         struct virtnet_info *vi = netdev_priv(dev);
1366
1367         ethtool_cmd_speed_set(cmd, vi->speed);
1368         cmd->duplex = vi->duplex;
1369         cmd->port = PORT_OTHER;
1370
1371         return 0;
1372 }
1373
1374 static void virtnet_init_settings(struct net_device *dev)
1375 {
1376         struct virtnet_info *vi = netdev_priv(dev);
1377
1378         vi->speed = SPEED_UNKNOWN;
1379         vi->duplex = DUPLEX_UNKNOWN;
1380 }
1381
1382 static const struct ethtool_ops virtnet_ethtool_ops = {
1383         .get_drvinfo = virtnet_get_drvinfo,
1384         .get_link = ethtool_op_get_link,
1385         .get_ringparam = virtnet_get_ringparam,
1386         .set_channels = virtnet_set_channels,
1387         .get_channels = virtnet_get_channels,
1388         .get_ts_info = ethtool_op_get_ts_info,
1389         .get_settings = virtnet_get_settings,
1390         .set_settings = virtnet_set_settings,
1391 };
1392
1393 #define MIN_MTU 68
1394 #define MAX_MTU 65535
1395
1396 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1397 {
1398         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1399                 return -EINVAL;
1400         dev->mtu = new_mtu;
1401         return 0;
1402 }
1403
1404 static const struct net_device_ops virtnet_netdev = {
1405         .ndo_open            = virtnet_open,
1406         .ndo_stop            = virtnet_close,
1407         .ndo_start_xmit      = start_xmit,
1408         .ndo_validate_addr   = eth_validate_addr,
1409         .ndo_set_mac_address = virtnet_set_mac_address,
1410         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1411         .ndo_change_mtu      = virtnet_change_mtu,
1412         .ndo_get_stats64     = virtnet_stats,
1413         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1414         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1415 #ifdef CONFIG_NET_POLL_CONTROLLER
1416         .ndo_poll_controller = virtnet_netpoll,
1417 #endif
1418 #ifdef CONFIG_NET_RX_BUSY_POLL
1419         .ndo_busy_poll          = virtnet_busy_poll,
1420 #endif
1421 };
1422
1423 static void virtnet_config_changed_work(struct work_struct *work)
1424 {
1425         struct virtnet_info *vi =
1426                 container_of(work, struct virtnet_info, config_work);
1427         u16 v;
1428
1429         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
1430                                  struct virtio_net_config, status, &v) < 0)
1431                 return;
1432
1433         if (v & VIRTIO_NET_S_ANNOUNCE) {
1434                 netdev_notify_peers(vi->dev);
1435                 virtnet_ack_link_announce(vi);
1436         }
1437
1438         /* Ignore unknown (future) status bits */
1439         v &= VIRTIO_NET_S_LINK_UP;
1440
1441         if (vi->status == v)
1442                 return;
1443
1444         vi->status = v;
1445
1446         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1447                 netif_carrier_on(vi->dev);
1448                 netif_tx_wake_all_queues(vi->dev);
1449         } else {
1450                 netif_carrier_off(vi->dev);
1451                 netif_tx_stop_all_queues(vi->dev);
1452         }
1453 }
1454
1455 static void virtnet_config_changed(struct virtio_device *vdev)
1456 {
1457         struct virtnet_info *vi = vdev->priv;
1458
1459         schedule_work(&vi->config_work);
1460 }
1461
1462 static void virtnet_free_queues(struct virtnet_info *vi)
1463 {
1464         int i;
1465
1466         for (i = 0; i < vi->max_queue_pairs; i++) {
1467                 napi_hash_del(&vi->rq[i].napi);
1468                 netif_napi_del(&vi->rq[i].napi);
1469         }
1470
1471         kfree(vi->rq);
1472         kfree(vi->sq);
1473 }
1474
1475 static void free_receive_bufs(struct virtnet_info *vi)
1476 {
1477         int i;
1478
1479         for (i = 0; i < vi->max_queue_pairs; i++) {
1480                 while (vi->rq[i].pages)
1481                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1482         }
1483 }
1484
1485 static void free_receive_page_frags(struct virtnet_info *vi)
1486 {
1487         int i;
1488         for (i = 0; i < vi->max_queue_pairs; i++)
1489                 if (vi->rq[i].alloc_frag.page)
1490                         put_page(vi->rq[i].alloc_frag.page);
1491 }
1492
1493 static void free_unused_bufs(struct virtnet_info *vi)
1494 {
1495         void *buf;
1496         int i;
1497
1498         for (i = 0; i < vi->max_queue_pairs; i++) {
1499                 struct virtqueue *vq = vi->sq[i].vq;
1500                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1501                         dev_kfree_skb(buf);
1502         }
1503
1504         for (i = 0; i < vi->max_queue_pairs; i++) {
1505                 struct virtqueue *vq = vi->rq[i].vq;
1506
1507                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1508                         if (vi->mergeable_rx_bufs) {
1509                                 unsigned long ctx = (unsigned long)buf;
1510                                 void *base = mergeable_ctx_to_buf_address(ctx);
1511                                 put_page(virt_to_head_page(base));
1512                         } else if (vi->big_packets) {
1513                                 give_pages(&vi->rq[i], buf);
1514                         } else {
1515                                 dev_kfree_skb(buf);
1516                         }
1517                 }
1518         }
1519 }
1520
1521 static void virtnet_del_vqs(struct virtnet_info *vi)
1522 {
1523         struct virtio_device *vdev = vi->vdev;
1524
1525         virtnet_clean_affinity(vi, -1);
1526
1527         vdev->config->del_vqs(vdev);
1528
1529         virtnet_free_queues(vi);
1530 }
1531
1532 static int virtnet_find_vqs(struct virtnet_info *vi)
1533 {
1534         vq_callback_t **callbacks;
1535         struct virtqueue **vqs;
1536         int ret = -ENOMEM;
1537         int i, total_vqs;
1538         const char **names;
1539
1540         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1541          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1542          * possible control vq.
1543          */
1544         total_vqs = vi->max_queue_pairs * 2 +
1545                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1546
1547         /* Allocate space for find_vqs parameters */
1548         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1549         if (!vqs)
1550                 goto err_vq;
1551         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1552         if (!callbacks)
1553                 goto err_callback;
1554         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1555         if (!names)
1556                 goto err_names;
1557
1558         /* Parameters for control virtqueue, if any */
1559         if (vi->has_cvq) {
1560                 callbacks[total_vqs - 1] = NULL;
1561                 names[total_vqs - 1] = "control";
1562         }
1563
1564         /* Allocate/initialize parameters for send/receive virtqueues */
1565         for (i = 0; i < vi->max_queue_pairs; i++) {
1566                 callbacks[rxq2vq(i)] = skb_recv_done;
1567                 callbacks[txq2vq(i)] = skb_xmit_done;
1568                 sprintf(vi->rq[i].name, "input.%d", i);
1569                 sprintf(vi->sq[i].name, "output.%d", i);
1570                 names[rxq2vq(i)] = vi->rq[i].name;
1571                 names[txq2vq(i)] = vi->sq[i].name;
1572         }
1573
1574         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1575                                          names);
1576         if (ret)
1577                 goto err_find;
1578
1579         if (vi->has_cvq) {
1580                 vi->cvq = vqs[total_vqs - 1];
1581                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1582                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1583         }
1584
1585         for (i = 0; i < vi->max_queue_pairs; i++) {
1586                 vi->rq[i].vq = vqs[rxq2vq(i)];
1587                 vi->sq[i].vq = vqs[txq2vq(i)];
1588         }
1589
1590         kfree(names);
1591         kfree(callbacks);
1592         kfree(vqs);
1593
1594         return 0;
1595
1596 err_find:
1597         kfree(names);
1598 err_names:
1599         kfree(callbacks);
1600 err_callback:
1601         kfree(vqs);
1602 err_vq:
1603         return ret;
1604 }
1605
1606 static int virtnet_alloc_queues(struct virtnet_info *vi)
1607 {
1608         int i;
1609
1610         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1611         if (!vi->sq)
1612                 goto err_sq;
1613         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1614         if (!vi->rq)
1615                 goto err_rq;
1616
1617         INIT_DELAYED_WORK(&vi->refill, refill_work);
1618         for (i = 0; i < vi->max_queue_pairs; i++) {
1619                 vi->rq[i].pages = NULL;
1620                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1621                                napi_weight);
1622
1623                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1624                 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
1625                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1626         }
1627
1628         return 0;
1629
1630 err_rq:
1631         kfree(vi->sq);
1632 err_sq:
1633         return -ENOMEM;
1634 }
1635
1636 static int init_vqs(struct virtnet_info *vi)
1637 {
1638         int ret;
1639
1640         /* Allocate send & receive queues */
1641         ret = virtnet_alloc_queues(vi);
1642         if (ret)
1643                 goto err;
1644
1645         ret = virtnet_find_vqs(vi);
1646         if (ret)
1647                 goto err_free;
1648
1649         get_online_cpus();
1650         virtnet_set_affinity(vi);
1651         put_online_cpus();
1652
1653         return 0;
1654
1655 err_free:
1656         virtnet_free_queues(vi);
1657 err:
1658         return ret;
1659 }
1660
1661 #ifdef CONFIG_SYSFS
1662 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
1663                 struct rx_queue_attribute *attribute, char *buf)
1664 {
1665         struct virtnet_info *vi = netdev_priv(queue->dev);
1666         unsigned int queue_index = get_netdev_rx_queue_index(queue);
1667         struct ewma_pkt_len *avg;
1668
1669         BUG_ON(queue_index >= vi->max_queue_pairs);
1670         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
1671         return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
1672 }
1673
1674 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
1675         __ATTR_RO(mergeable_rx_buffer_size);
1676
1677 static struct attribute *virtio_net_mrg_rx_attrs[] = {
1678         &mergeable_rx_buffer_size_attribute.attr,
1679         NULL
1680 };
1681
1682 static const struct attribute_group virtio_net_mrg_rx_group = {
1683         .name = "virtio_net",
1684         .attrs = virtio_net_mrg_rx_attrs
1685 };
1686 #endif
1687
1688 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
1689                                     unsigned int fbit,
1690                                     const char *fname, const char *dname)
1691 {
1692         if (!virtio_has_feature(vdev, fbit))
1693                 return false;
1694
1695         dev_err(&vdev->dev, "device advertises feature %s but not %s",
1696                 fname, dname);
1697
1698         return true;
1699 }
1700
1701 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)                       \
1702         virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
1703
1704 static bool virtnet_validate_features(struct virtio_device *vdev)
1705 {
1706         if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
1707             (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
1708                              "VIRTIO_NET_F_CTRL_VQ") ||
1709              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
1710                              "VIRTIO_NET_F_CTRL_VQ") ||
1711              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
1712                              "VIRTIO_NET_F_CTRL_VQ") ||
1713              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
1714              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
1715                              "VIRTIO_NET_F_CTRL_VQ"))) {
1716                 return false;
1717         }
1718
1719         return true;
1720 }
1721
1722 static int virtnet_probe(struct virtio_device *vdev)
1723 {
1724         int i, err;
1725         struct net_device *dev;
1726         struct virtnet_info *vi;
1727         u16 max_queue_pairs;
1728         int mtu;
1729
1730         if (!vdev->config->get) {
1731                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
1732                         __func__);
1733                 return -EINVAL;
1734         }
1735
1736         if (!virtnet_validate_features(vdev))
1737                 return -EINVAL;
1738
1739         /* Find if host supports multiqueue virtio_net device */
1740         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
1741                                    struct virtio_net_config,
1742                                    max_virtqueue_pairs, &max_queue_pairs);
1743
1744         /* We need at least 2 queue's */
1745         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1746             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1747             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1748                 max_queue_pairs = 1;
1749
1750         /* Allocate ourselves a network device with room for our info */
1751         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1752         if (!dev)
1753                 return -ENOMEM;
1754
1755         /* Set up network device as normal. */
1756         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1757         dev->netdev_ops = &virtnet_netdev;
1758         dev->features = NETIF_F_HIGHDMA;
1759
1760         dev->ethtool_ops = &virtnet_ethtool_ops;
1761         SET_NETDEV_DEV(dev, &vdev->dev);
1762
1763         /* Do we support "hardware" checksums? */
1764         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1765                 /* This opens up the world of extra features. */
1766                 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
1767                 if (csum)
1768                         dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
1769
1770                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1771                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1772                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1773                 }
1774                 /* Individual feature bits: what can host handle? */
1775                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1776                         dev->hw_features |= NETIF_F_TSO;
1777                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1778                         dev->hw_features |= NETIF_F_TSO6;
1779                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1780                         dev->hw_features |= NETIF_F_TSO_ECN;
1781                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1782                         dev->hw_features |= NETIF_F_UFO;
1783
1784                 dev->features |= NETIF_F_GSO_ROBUST;
1785
1786                 if (gso)
1787                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1788                 /* (!csum && gso) case will be fixed by register_netdev() */
1789         }
1790         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
1791                 dev->features |= NETIF_F_RXCSUM;
1792
1793         dev->vlan_features = dev->features;
1794
1795         /* Configuration may specify what MAC to use.  Otherwise random. */
1796         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
1797                 virtio_cread_bytes(vdev,
1798                                    offsetof(struct virtio_net_config, mac),
1799                                    dev->dev_addr, dev->addr_len);
1800         else
1801                 eth_hw_addr_random(dev);
1802
1803         /* Set up our device-specific information */
1804         vi = netdev_priv(dev);
1805         vi->dev = dev;
1806         vi->vdev = vdev;
1807         vdev->priv = vi;
1808         vi->stats = alloc_percpu(struct virtnet_stats);
1809         err = -ENOMEM;
1810         if (vi->stats == NULL)
1811                 goto free;
1812
1813         for_each_possible_cpu(i) {
1814                 struct virtnet_stats *virtnet_stats;
1815                 virtnet_stats = per_cpu_ptr(vi->stats, i);
1816                 u64_stats_init(&virtnet_stats->tx_syncp);
1817                 u64_stats_init(&virtnet_stats->rx_syncp);
1818         }
1819
1820         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1821
1822         /* If we can receive ANY GSO packets, we must allocate large ones. */
1823         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1824             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1825             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
1826             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
1827                 vi->big_packets = true;
1828
1829         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1830                 vi->mergeable_rx_bufs = true;
1831
1832         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
1833             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
1834                 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1835         else
1836                 vi->hdr_len = sizeof(struct virtio_net_hdr);
1837
1838         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
1839             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
1840                 vi->any_header_sg = true;
1841
1842         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1843                 vi->has_cvq = true;
1844
1845         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
1846                 mtu = virtio_cread16(vdev,
1847                                      offsetof(struct virtio_net_config,
1848                                               mtu));
1849                 if (virtnet_change_mtu(dev, mtu))
1850                         __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
1851         }
1852
1853         if (vi->any_header_sg)
1854                 dev->needed_headroom = vi->hdr_len;
1855
1856         /* Use single tx/rx queue pair as default */
1857         vi->curr_queue_pairs = 1;
1858         vi->max_queue_pairs = max_queue_pairs;
1859
1860         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1861         err = init_vqs(vi);
1862         if (err)
1863                 goto free_stats;
1864
1865 #ifdef CONFIG_SYSFS
1866         if (vi->mergeable_rx_bufs)
1867                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
1868 #endif
1869         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
1870         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
1871
1872         virtnet_init_settings(dev);
1873
1874         err = register_netdev(dev);
1875         if (err) {
1876                 pr_debug("virtio_net: registering device failed\n");
1877                 goto free_vqs;
1878         }
1879
1880         virtio_device_ready(vdev);
1881
1882         vi->nb.notifier_call = &virtnet_cpu_callback;
1883         err = register_hotcpu_notifier(&vi->nb);
1884         if (err) {
1885                 pr_debug("virtio_net: registering cpu notifier failed\n");
1886                 goto free_unregister_netdev;
1887         }
1888
1889         /* Assume link up if device can't report link status,
1890            otherwise get link status from config. */
1891         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1892                 netif_carrier_off(dev);
1893                 schedule_work(&vi->config_work);
1894         } else {
1895                 vi->status = VIRTIO_NET_S_LINK_UP;
1896                 netif_carrier_on(dev);
1897         }
1898
1899         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1900                  dev->name, max_queue_pairs);
1901
1902         return 0;
1903
1904 free_unregister_netdev:
1905         vi->vdev->config->reset(vdev);
1906
1907         unregister_netdev(dev);
1908 free_vqs:
1909         cancel_delayed_work_sync(&vi->refill);
1910         free_receive_page_frags(vi);
1911         virtnet_del_vqs(vi);
1912 free_stats:
1913         free_percpu(vi->stats);
1914 free:
1915         free_netdev(dev);
1916         return err;
1917 }
1918
1919 static void remove_vq_common(struct virtnet_info *vi)
1920 {
1921         vi->vdev->config->reset(vi->vdev);
1922
1923         /* Free unused buffers in both send and recv, if any. */
1924         free_unused_bufs(vi);
1925
1926         free_receive_bufs(vi);
1927
1928         free_receive_page_frags(vi);
1929
1930         virtnet_del_vqs(vi);
1931 }
1932
1933 static void virtnet_remove(struct virtio_device *vdev)
1934 {
1935         struct virtnet_info *vi = vdev->priv;
1936
1937         unregister_hotcpu_notifier(&vi->nb);
1938
1939         /* Make sure no work handler is accessing the device. */
1940         flush_work(&vi->config_work);
1941
1942         unregister_netdev(vi->dev);
1943
1944         remove_vq_common(vi);
1945
1946         free_percpu(vi->stats);
1947         free_netdev(vi->dev);
1948 }
1949
1950 #ifdef CONFIG_PM_SLEEP
1951 static int virtnet_freeze(struct virtio_device *vdev)
1952 {
1953         struct virtnet_info *vi = vdev->priv;
1954         int i;
1955
1956         unregister_hotcpu_notifier(&vi->nb);
1957
1958         /* Make sure no work handler is accessing the device */
1959         flush_work(&vi->config_work);
1960
1961         netif_device_detach(vi->dev);
1962         cancel_delayed_work_sync(&vi->refill);
1963
1964         if (netif_running(vi->dev)) {
1965                 for (i = 0; i < vi->max_queue_pairs; i++)
1966                         napi_disable(&vi->rq[i].napi);
1967         }
1968
1969         remove_vq_common(vi);
1970
1971         return 0;
1972 }
1973
1974 static int virtnet_restore(struct virtio_device *vdev)
1975 {
1976         struct virtnet_info *vi = vdev->priv;
1977         int err, i;
1978
1979         err = init_vqs(vi);
1980         if (err)
1981                 return err;
1982
1983         virtio_device_ready(vdev);
1984
1985         if (netif_running(vi->dev)) {
1986                 for (i = 0; i < vi->curr_queue_pairs; i++)
1987                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1988                                 schedule_delayed_work(&vi->refill, 0);
1989
1990                 for (i = 0; i < vi->max_queue_pairs; i++)
1991                         virtnet_napi_enable(&vi->rq[i]);
1992         }
1993
1994         netif_device_attach(vi->dev);
1995
1996         rtnl_lock();
1997         virtnet_set_queues(vi, vi->curr_queue_pairs);
1998         rtnl_unlock();
1999
2000         err = register_hotcpu_notifier(&vi->nb);
2001         if (err)
2002                 return err;
2003
2004         return 0;
2005 }
2006 #endif
2007
2008 static struct virtio_device_id id_table[] = {
2009         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
2010         { 0 },
2011 };
2012
2013 static unsigned int features[] = {
2014         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
2015         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
2016         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
2017         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
2018         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
2019         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
2020         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
2021         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
2022         VIRTIO_NET_F_CTRL_MAC_ADDR,
2023         VIRTIO_F_ANY_LAYOUT,
2024         VIRTIO_NET_F_MTU,
2025 };
2026
2027 static struct virtio_driver virtio_net_driver = {
2028         .feature_table = features,
2029         .feature_table_size = ARRAY_SIZE(features),
2030         .driver.name =  KBUILD_MODNAME,
2031         .driver.owner = THIS_MODULE,
2032         .id_table =     id_table,
2033         .probe =        virtnet_probe,
2034         .remove =       virtnet_remove,
2035         .config_changed = virtnet_config_changed,
2036 #ifdef CONFIG_PM_SLEEP
2037         .freeze =       virtnet_freeze,
2038         .restore =      virtnet_restore,
2039 #endif
2040 };
2041
2042 module_virtio_driver(virtio_net_driver);
2043
2044 MODULE_DEVICE_TABLE(virtio, id_table);
2045 MODULE_DESCRIPTION("Virtio network driver");
2046 MODULE_LICENSE("GPL");