drivers/net/virtio_net.c

   1 /* A network driver using virtio.
   2  *
   3  * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18 //#define DEBUG
  19 #include <linux/netdevice.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/ethtool.h>
  22 #include <linux/module.h>
  23 #include <linux/virtio.h>
  24 #include <linux/virtio_net.h>
  25 #include <linux/scatterlist.h>
  26 #include <linux/if_vlan.h>
  27 #include <linux/slab.h>
  28 #include <linux/cpu.h>
  29 #include <linux/average.h>
  30 #include <net/busy_poll.h>
  31
  32 static int napi_weight = NAPI_POLL_WEIGHT;
  33 module_param(napi_weight, int, 0444);
  34
  35 static bool csum = true, gso = true;
  36 module_param(csum, bool, 0444);
  37 module_param(gso, bool, 0444);
  38
  39 /* FIXME: MTU in config. */
  40 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  41 #define GOOD_COPY_LEN   128
  42
  43 /* Weight used for the RX packet size EWMA. The average packet size is used to
  44  * determine the packet buffer size when refilling RX rings. As the entire RX
  45  * ring may be refilled at once, the weight is chosen so that the EWMA will be
  46  * insensitive to short-term, transient changes in packet size.
  47  */
  48 #define RECEIVE_AVG_WEIGHT 64
  49
  50 /* Minimum alignment for mergeable packet buffers. */
  51 #define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
  52
  53 #define VIRTNET_DRIVER_VERSION "1.0.0"
  54
  55 struct virtnet_stats {
  56         struct u64_stats_sync tx_syncp;
  57         struct u64_stats_sync rx_syncp;
  58         u64 tx_bytes;
  59         u64 tx_packets;
  60
  61         u64 rx_bytes;
  62         u64 rx_packets;
  63 };
  64
  65 /* Internal representation of a send virtqueue */
  66 struct send_queue {
  67         /* Virtqueue associated with this send _queue */
  68         struct virtqueue *vq;
  69
  70         /* TX: fragments + linear part + virtio header */
  71         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  72
  73         /* Name of the send queue: output.$index */
  74         char name[40];
  75 };
  76
  77 /* Internal representation of a receive virtqueue */
  78 struct receive_queue {
  79         /* Virtqueue associated with this receive_queue */
  80         struct virtqueue *vq;
  81
  82         struct napi_struct napi;
  83
  84         /* Chain pages by the private ptr. */
  85         struct page *pages;
  86
  87         /* Average packet length for mergeable receive buffers. */
  88         struct ewma mrg_avg_pkt_len;
  89
  90         /* Page frag for packet buffer allocation. */
  91         struct page_frag alloc_frag;
  92
  93         /* RX: fragments + linear part + virtio header */
  94         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  95
  96         /* Name of this receive queue: input.$index */
  97         char name[40];
  98 };
  99
 100 struct virtnet_info {
 101         struct virtio_device *vdev;
 102         struct virtqueue *cvq;
 103         struct net_device *dev;
 104         struct send_queue *sq;
 105         struct receive_queue *rq;
 106         unsigned int status;
 107
 108         /* Max # of queue pairs supported by the device */
 109         u16 max_queue_pairs;
 110
 111         /* # of queue pairs currently used by the driver */
 112         u16 curr_queue_pairs;
 113
 114         /* I like... big packets and I cannot lie! */
 115         bool big_packets;
 116
 117         /* Host will merge rx buffers for big packets (shake it! shake it!) */
 118         bool mergeable_rx_bufs;
 119
 120         /* Has control virtqueue */
 121         bool has_cvq;
 122
 123         /* Host can handle any s/g split between our header and packet data */
 124         bool any_header_sg;
 125
 126         /* enable config space updates */
 127         bool config_enable;
 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         /* Lock for config space updates */
 139         struct mutex config_lock;
 140
 141         /* Does the affinity hint is set for virtqueues? */
 142         bool affinity_hint_set;
 143
 144         /* CPU hot plug notifier */
 145         struct notifier_block nb;
 146 };
 147
 148 struct skb_vnet_hdr {
 149         union {
 150                 struct virtio_net_hdr hdr;
 151                 struct virtio_net_hdr_mrg_rxbuf mhdr;
 152         };
 153 };
 154
 155 struct padded_vnet_hdr {
 156         struct virtio_net_hdr hdr;
 157         /*
 158          * virtio_net_hdr should be in a separated sg buffer because of a
 159          * QEMU bug, and data sg buffer shares same page with this header sg.
 160          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
 161          */
 162         char padding[6];
 163 };
 164
 165 /* Converting between virtqueue no. and kernel tx/rx queue no.
 166  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 167  */
 168 static int vq2txq(struct virtqueue *vq)
 169 {
 170         return (vq->index - 1) / 2;
 171 }
 172
 173 static int txq2vq(int txq)
 174 {
 175         return txq * 2 + 1;
 176 }
 177
 178 static int vq2rxq(struct virtqueue *vq)
 179 {
 180         return vq->index / 2;
 181 }
 182
 183 static int rxq2vq(int rxq)
 184 {
 185         return rxq * 2;
 186 }
 187
 188 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
 189 {
 190         return (struct skb_vnet_hdr *)skb->cb;
 191 }
 192
 193 /*
 194  * private is used to chain pages for big packets, put the whole
 195  * most recent used list in the beginning for reuse
 196  */
 197 static void give_pages(struct receive_queue *rq, struct page *page)
 198 {
 199         struct page *end;
 200
 201         /* Find end of list, sew whole thing into vi->rq.pages. */
 202         for (end = page; end->private; end = (struct page *)end->private);
 203         end->private = (unsigned long)rq->pages;
 204         rq->pages = page;
 205 }
 206
 207 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 208 {
 209         struct page *p = rq->pages;
 210
 211         if (p) {
 212                 rq->pages = (struct page *)p->private;
 213                 /* clear private here, it is used to chain pages */
 214                 p->private = 0;
 215         } else
 216                 p = alloc_page(gfp_mask);
 217         return p;
 218 }
 219
 220 static void skb_xmit_done(struct virtqueue *vq)
 221 {
 222         struct virtnet_info *vi = vq->vdev->priv;
 223
 224         /* Suppress further interrupts. */
 225         virtqueue_disable_cb(vq);
 226
 227         /* We were probably waiting for more output buffers. */
 228         netif_wake_subqueue(vi->dev, vq2txq(vq));
 229 }
 230
 231 static unsigned int mergeable_ctx_to_buf_truesize(unsigned long mrg_ctx)
 232 {
 233         unsigned int truesize = mrg_ctx & (MERGEABLE_BUFFER_ALIGN - 1);
 234         return (truesize + 1) * MERGEABLE_BUFFER_ALIGN;
 235 }
 236
 237 static void *mergeable_ctx_to_buf_address(unsigned long mrg_ctx)
 238 {
 239         return (void *)(mrg_ctx & -MERGEABLE_BUFFER_ALIGN);
 240
 241 }
 242
 243 static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize)
 244 {
 245         unsigned int size = truesize / MERGEABLE_BUFFER_ALIGN;
 246         return (unsigned long)buf | (size - 1);
 247 }
 248
 249 /* Called from bottom half context */
 250 static struct sk_buff *page_to_skb(struct receive_queue *rq,
 251                                    struct page *page, unsigned int offset,
 252                                    unsigned int len, unsigned int truesize)
 253 {
 254         struct virtnet_info *vi = rq->vq->vdev->priv;
 255         struct sk_buff *skb;
 256         struct skb_vnet_hdr *hdr;
 257         unsigned int copy, hdr_len, hdr_padded_len;
 258         char *p;
 259
 260         p = page_address(page) + offset;
 261
 262         /* copy small packet so we can reuse these pages for small data */
 263         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
 264         if (unlikely(!skb))
 265                 return NULL;
 266
 267         hdr = skb_vnet_hdr(skb);
 268
 269         if (vi->mergeable_rx_bufs) {
 270                 hdr_len = sizeof hdr->mhdr;
 271                 hdr_padded_len = sizeof hdr->mhdr;
 272         } else {
 273                 hdr_len = sizeof hdr->hdr;
 274                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 275         }
 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(void *buf, unsigned int len)
 327 {
 328         struct sk_buff * skb = buf;
 329
 330         len -= sizeof(struct virtio_net_hdr);
 331         skb_trim(skb, len);
 332
 333         return skb;
 334 }
 335
 336 static struct sk_buff *receive_big(struct net_device *dev,
 337                                    struct receive_queue *rq,
 338                                    void *buf,
 339                                    unsigned int len)
 340 {
 341         struct page *page = buf;
 342         struct sk_buff *skb = page_to_skb(rq, page, 0, len, PAGE_SIZE);
 343
 344         if (unlikely(!skb))
 345                 goto err;
 346
 347         return skb;
 348
 349 err:
 350         dev->stats.rx_dropped++;
 351         give_pages(rq, page);
 352         return NULL;
 353 }
 354
 355 static struct sk_buff *receive_mergeable(struct net_device *dev,
 356                                          struct receive_queue *rq,
 357                                          unsigned long ctx,
 358                                          unsigned int len)
 359 {
 360         void *buf = mergeable_ctx_to_buf_address(ctx);
 361         struct skb_vnet_hdr *hdr = buf;
 362         int num_buf = hdr->mhdr.num_buffers;
 363         struct page *page = virt_to_head_page(buf);
 364         int offset = buf - page_address(page);
 365         unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 366
 367         struct sk_buff *head_skb = page_to_skb(rq, page, offset, len, truesize);
 368         struct sk_buff *curr_skb = head_skb;
 369
 370         if (unlikely(!curr_skb))
 371                 goto err_skb;
 372         while (--num_buf) {
 373                 int num_skb_frags;
 374
 375                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 376                 if (unlikely(!ctx)) {
 377                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
 378                                  dev->name, num_buf, hdr->mhdr.num_buffers);
 379                         dev->stats.rx_length_errors++;
 380                         goto err_buf;
 381                 }
 382
 383                 buf = mergeable_ctx_to_buf_address(ctx);
 384                 page = virt_to_head_page(buf);
 385
 386                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
 387                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
 388                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
 389
 390                         if (unlikely(!nskb))
 391                                 goto err_skb;
 392                         if (curr_skb == head_skb)
 393                                 skb_shinfo(curr_skb)->frag_list = nskb;
 394                         else
 395                                 curr_skb->next = nskb;
 396                         curr_skb = nskb;
 397                         head_skb->truesize += nskb->truesize;
 398                         num_skb_frags = 0;
 399                 }
 400                 truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 401                 if (curr_skb != head_skb) {
 402                         head_skb->data_len += len;
 403                         head_skb->len += len;
 404                         head_skb->truesize += truesize;
 405                 }
 406                 offset = buf - page_address(page);
 407                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
 408                         put_page(page);
 409                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
 410                                              len, truesize);
 411                 } else {
 412                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
 413                                         offset, len, truesize);
 414                 }
 415         }
 416
 417         ewma_add(&rq->mrg_avg_pkt_len, head_skb->len);
 418         return head_skb;
 419
 420 err_skb:
 421         put_page(page);
 422         while (--num_buf) {
 423                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 424                 if (unlikely(!ctx)) {
 425                         pr_debug("%s: rx error: %d buffers missing\n",
 426                                  dev->name, num_buf);
 427                         dev->stats.rx_length_errors++;
 428                         break;
 429                 }
 430                 page = virt_to_head_page(mergeable_ctx_to_buf_address(ctx));
 431                 put_page(page);
 432         }
 433 err_buf:
 434         dev->stats.rx_dropped++;
 435         dev_kfree_skb(head_skb);
 436         return NULL;
 437 }
 438
 439 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
 440 {
 441         struct virtnet_info *vi = rq->vq->vdev->priv;
 442         struct net_device *dev = vi->dev;
 443         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 444         struct sk_buff *skb;
 445         struct skb_vnet_hdr *hdr;
 446
 447         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
 448                 pr_debug("%s: short packet %i\n", dev->name, len);
 449                 dev->stats.rx_length_errors++;
 450                 if (vi->mergeable_rx_bufs) {
 451                         unsigned long ctx = (unsigned long)buf;
 452                         void *base = mergeable_ctx_to_buf_address(ctx);
 453                         put_page(virt_to_head_page(base));
 454                 } else if (vi->big_packets) {
 455                         give_pages(rq, buf);
 456                 } else {
 457                         dev_kfree_skb(buf);
 458                 }
 459                 return;
 460         }
 461
 462         if (vi->mergeable_rx_bufs)
 463                 skb = receive_mergeable(dev, rq, (unsigned long)buf, len);
 464         else if (vi->big_packets)
 465                 skb = receive_big(dev, rq, buf, len);
 466         else
 467                 skb = receive_small(buf, len);
 468
 469         if (unlikely(!skb))
 470                 return;
 471
 472         hdr = skb_vnet_hdr(skb);
 473
 474         u64_stats_update_begin(&stats->rx_syncp);
 475         stats->rx_bytes += skb->len;
 476         stats->rx_packets++;
 477         u64_stats_update_end(&stats->rx_syncp);
 478
 479         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 480                 pr_debug("Needs csum!\n");
 481                 if (!skb_partial_csum_set(skb,
 482                                           hdr->hdr.csum_start,
 483                                           hdr->hdr.csum_offset))
 484                         goto frame_err;
 485         } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
 486                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 487         }
 488
 489         skb->protocol = eth_type_trans(skb, dev);
 490         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 491                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 492
 493         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 494                 pr_debug("GSO!\n");
 495                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 496                 case VIRTIO_NET_HDR_GSO_TCPV4:
 497                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 498                         break;
 499                 case VIRTIO_NET_HDR_GSO_UDP:
 500                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 501                         break;
 502                 case VIRTIO_NET_HDR_GSO_TCPV6:
 503                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 504                         break;
 505                 default:
 506                         net_warn_ratelimited("%s: bad gso type %u.\n",
 507                                              dev->name, hdr->hdr.gso_type);
 508                         goto frame_err;
 509                 }
 510
 511                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 512                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 513
 514                 skb_shinfo(skb)->gso_size = 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         skb_mark_napi_id(skb, &rq->napi);
 526
 527         netif_receive_skb(skb);
 528         return;
 529
 530 frame_err:
 531         dev->stats.rx_frame_errors++;
 532         dev_kfree_skb(skb);
 533 }
 534
 535 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
 536 {
 537         struct virtnet_info *vi = rq->vq->vdev->priv;
 538         struct sk_buff *skb;
 539         struct skb_vnet_hdr *hdr;
 540         int err;
 541
 542         skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
 543         if (unlikely(!skb))
 544                 return -ENOMEM;
 545
 546         skb_put(skb, GOOD_PACKET_LEN);
 547
 548         hdr = skb_vnet_hdr(skb);
 549         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
 550         sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
 551         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 552
 553         err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
 554         if (err < 0)
 555                 dev_kfree_skb(skb);
 556
 557         return err;
 558 }
 559
 560 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
 561 {
 562         struct page *first, *list = NULL;
 563         char *p;
 564         int i, err, offset;
 565
 566         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
 567
 568         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 569         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 570                 first = get_a_page(rq, gfp);
 571                 if (!first) {
 572                         if (list)
 573                                 give_pages(rq, list);
 574                         return -ENOMEM;
 575                 }
 576                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
 577
 578                 /* chain new page in list head to match sg */
 579                 first->private = (unsigned long)list;
 580                 list = first;
 581         }
 582
 583         first = get_a_page(rq, gfp);
 584         if (!first) {
 585                 give_pages(rq, list);
 586                 return -ENOMEM;
 587         }
 588         p = page_address(first);
 589
 590         /* rq->sg[0], rq->sg[1] share the same page */
 591         /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
 592         sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
 593
 594         /* rq->sg[1] for data packet, from offset */
 595         offset = sizeof(struct padded_vnet_hdr);
 596         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
 597
 598         /* chain first in list head */
 599         first->private = (unsigned long)list;
 600         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
 601                                   first, gfp);
 602         if (err < 0)
 603                 give_pages(rq, first);
 604
 605         return err;
 606 }
 607
 608 static unsigned int get_mergeable_buf_len(struct ewma *avg_pkt_len)
 609 {
 610         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 611         unsigned int len;
 612
 613         len = hdr_len + clamp_t(unsigned int, ewma_read(avg_pkt_len),
 614                         GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
 615         return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
 616 }
 617
 618 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
 619 {
 620         struct page_frag *alloc_frag = &rq->alloc_frag;
 621         char *buf;
 622         unsigned long ctx;
 623         int err;
 624         unsigned int len, hole;
 625
 626         len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
 627         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
 628                 return -ENOMEM;
 629
 630         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
 631         ctx = mergeable_buf_to_ctx(buf, len);
 632         get_page(alloc_frag->page);
 633         alloc_frag->offset += len;
 634         hole = alloc_frag->size - alloc_frag->offset;
 635         if (hole < len) {
 636                 /* To avoid internal fragmentation, if there is very likely not
 637                  * enough space for another buffer, add the remaining space to
 638                  * the current buffer. This extra space is not included in
 639                  * the truesize stored in ctx.
 640                  */
 641                 len += hole;
 642                 alloc_frag->offset += hole;
 643         }
 644
 645         sg_init_one(rq->sg, buf, len);
 646         err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
 647         if (err < 0)
 648                 put_page(virt_to_head_page(buf));
 649
 650         return err;
 651 }
 652
 653 /*
 654  * Returns false if we couldn't fill entirely (OOM).
 655  *
 656  * Normally run in the receive path, but can also be run from ndo_open
 657  * before we're receiving packets, or from refill_work which is
 658  * careful to disable receiving (using napi_disable).
 659  */
 660 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
 661 {
 662         struct virtnet_info *vi = rq->vq->vdev->priv;
 663         int err;
 664         bool oom;
 665
 666         gfp |= __GFP_COLD;
 667         do {
 668                 if (vi->mergeable_rx_bufs)
 669                         err = add_recvbuf_mergeable(rq, gfp);
 670                 else if (vi->big_packets)
 671                         err = add_recvbuf_big(rq, gfp);
 672                 else
 673                         err = add_recvbuf_small(rq, gfp);
 674
 675                 oom = err == -ENOMEM;
 676                 if (err)
 677                         break;
 678         } while (rq->vq->num_free);
 679         virtqueue_kick(rq->vq);
 680         return !oom;
 681 }
 682
 683 static void skb_recv_done(struct virtqueue *rvq)
 684 {
 685         struct virtnet_info *vi = rvq->vdev->priv;
 686         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 687
 688         /* Schedule NAPI, Suppress further interrupts if successful. */
 689         if (napi_schedule_prep(&rq->napi)) {
 690                 virtqueue_disable_cb(rvq);
 691                 __napi_schedule(&rq->napi);
 692         }
 693 }
 694
 695 static void virtnet_napi_enable(struct receive_queue *rq)
 696 {
 697         napi_enable(&rq->napi);
 698
 699         /* If all buffers were filled by other side before we napi_enabled, we
 700          * won't get another interrupt, so process any outstanding packets
 701          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 702          * We synchronize against interrupts via NAPI_STATE_SCHED */
 703         if (napi_schedule_prep(&rq->napi)) {
 704                 virtqueue_disable_cb(rq->vq);
 705                 local_bh_disable();
 706                 __napi_schedule(&rq->napi);
 707                 local_bh_enable();
 708         }
 709 }
 710
 711 static void refill_work(struct work_struct *work)
 712 {
 713         struct virtnet_info *vi =
 714                 container_of(work, struct virtnet_info, refill.work);
 715         bool still_empty;
 716         int i;
 717
 718         for (i = 0; i < vi->curr_queue_pairs; i++) {
 719                 struct receive_queue *rq = &vi->rq[i];
 720
 721                 napi_disable(&rq->napi);
 722                 still_empty = !try_fill_recv(rq, GFP_KERNEL);
 723                 virtnet_napi_enable(rq);
 724
 725                 /* In theory, this can happen: if we don't get any buffers in
 726                  * we will *never* try to fill again.
 727                  */
 728                 if (still_empty)
 729                         schedule_delayed_work(&vi->refill, HZ/2);
 730         }
 731 }
 732
 733 static int virtnet_receive(struct receive_queue *rq, int budget)
 734 {
 735         struct virtnet_info *vi = rq->vq->vdev->priv;
 736         unsigned int len, received = 0;
 737         void *buf;
 738
 739         while (received < budget &&
 740                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
 741                 receive_buf(rq, buf, len);
 742                 received++;
 743         }
 744
 745         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
 746                 if (!try_fill_recv(rq, GFP_ATOMIC))
 747                         schedule_delayed_work(&vi->refill, 0);
 748         }
 749
 750         return received;
 751 }
 752
 753 static int virtnet_poll(struct napi_struct *napi, int budget)
 754 {
 755         struct receive_queue *rq =
 756                 container_of(napi, struct receive_queue, napi);
 757         unsigned int r, received = 0;
 758
 759 again:
 760         received += virtnet_receive(rq, budget - received);
 761
 762         /* Out of packets? */
 763         if (received < budget) {
 764                 r = virtqueue_enable_cb_prepare(rq->vq);
 765                 napi_complete(napi);
 766                 if (unlikely(virtqueue_poll(rq->vq, r)) &&
 767                     napi_schedule_prep(napi)) {
 768                         virtqueue_disable_cb(rq->vq);
 769                         __napi_schedule(napi);
 770                         goto again;
 771                 }
 772         }
 773
 774         return received;
 775 }
 776
 777 #ifdef CONFIG_NET_RX_BUSY_POLL
 778 /* must be called with local_bh_disable()d */
 779 static int virtnet_busy_poll(struct napi_struct *napi)
 780 {
 781         struct receive_queue *rq =
 782                 container_of(napi, struct receive_queue, napi);
 783         struct virtnet_info *vi = rq->vq->vdev->priv;
 784         int r, received = 0, budget = 4;
 785
 786         if (!(vi->status & VIRTIO_NET_S_LINK_UP))
 787                 return LL_FLUSH_FAILED;
 788
 789         if (!napi_schedule_prep(napi))
 790                 return LL_FLUSH_BUSY;
 791
 792         virtqueue_disable_cb(rq->vq);
 793
 794 again:
 795         received += virtnet_receive(rq, budget);
 796
 797         r = virtqueue_enable_cb_prepare(rq->vq);
 798         clear_bit(NAPI_STATE_SCHED, &napi->state);
 799         if (unlikely(virtqueue_poll(rq->vq, r)) &&
 800             napi_schedule_prep(napi)) {
 801                 virtqueue_disable_cb(rq->vq);
 802                 if (received < budget) {
 803                         budget -= received;
 804                         goto again;
 805                 } else {
 806                         __napi_schedule(napi);
 807                 }
 808         }
 809
 810         return received;
 811 }
 812 #endif  /* CONFIG_NET_RX_BUSY_POLL */
 813
 814 static int virtnet_open(struct net_device *dev)
 815 {
 816         struct virtnet_info *vi = netdev_priv(dev);
 817         int i;
 818
 819         for (i = 0; i < vi->max_queue_pairs; i++) {
 820                 if (i < vi->curr_queue_pairs)
 821                         /* Make sure we have some buffers: if oom use wq. */
 822                         if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
 823                                 schedule_delayed_work(&vi->refill, 0);
 824                 virtnet_napi_enable(&vi->rq[i]);
 825         }
 826
 827         return 0;
 828 }
 829
 830 static void free_old_xmit_skbs(struct send_queue *sq)
 831 {
 832         struct sk_buff *skb;
 833         unsigned int len;
 834         struct virtnet_info *vi = sq->vq->vdev->priv;
 835         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 836
 837         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 838                 pr_debug("Sent skb %p\n", skb);
 839
 840                 u64_stats_update_begin(&stats->tx_syncp);
 841                 stats->tx_bytes += skb->len;
 842                 stats->tx_packets++;
 843                 u64_stats_update_end(&stats->tx_syncp);
 844
 845                 dev_kfree_skb_any(skb);
 846         }
 847 }
 848
 849 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 850 {
 851         struct skb_vnet_hdr *hdr;
 852         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 853         struct virtnet_info *vi = sq->vq->vdev->priv;
 854         unsigned num_sg;
 855         unsigned hdr_len;
 856         bool can_push;
 857
 858         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 859         if (vi->mergeable_rx_bufs)
 860                 hdr_len = sizeof hdr->mhdr;
 861         else
 862                 hdr_len = sizeof hdr->hdr;
 863
 864         can_push = vi->any_header_sg &&
 865                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
 866                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
 867         /* Even if we can, don't push here yet as this would skew
 868          * csum_start offset below. */
 869         if (can_push)
 870                 hdr = (struct skb_vnet_hdr *)(skb->data - hdr_len);
 871         else
 872                 hdr = skb_vnet_hdr(skb);
 873
 874         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 875                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 876                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
 877                 hdr->hdr.csum_offset = skb->csum_offset;
 878         } else {
 879                 hdr->hdr.flags = 0;
 880                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 881         }
 882
 883         if (skb_is_gso(skb)) {
 884                 hdr->hdr.hdr_len = skb_headlen(skb);
 885                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
 886                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 887                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 888                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 889                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 890                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 891                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 892                 else
 893                         BUG();
 894                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 895                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 896         } else {
 897                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 898                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
 899         }
 900
 901         if (vi->mergeable_rx_bufs)
 902                 hdr->mhdr.num_buffers = 0;
 903
 904         sg_init_table(sq->sg, MAX_SKB_FRAGS + 2);
 905         if (can_push) {
 906                 __skb_push(skb, hdr_len);
 907                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
 908                 /* Pull header back to avoid skew in tx bytes calculations. */
 909                 __skb_pull(skb, hdr_len);
 910         } else {
 911                 sg_set_buf(sq->sg, hdr, hdr_len);
 912                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
 913         }
 914         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
 915 }
 916
 917 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 918 {
 919         struct virtnet_info *vi = netdev_priv(dev);
 920         int qnum = skb_get_queue_mapping(skb);
 921         struct send_queue *sq = &vi->sq[qnum];
 922         int err;
 923
 924         /* Free up any pending old buffers before queueing new ones. */
 925         free_old_xmit_skbs(sq);
 926
 927         /* Try to transmit */
 928         err = xmit_skb(sq, skb);
 929
 930         /* This should not happen! */
 931         if (unlikely(err)) {
 932                 dev->stats.tx_fifo_errors++;
 933                 if (net_ratelimit())
 934                         dev_warn(&dev->dev,
 935                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
 936                 dev->stats.tx_dropped++;
 937                 dev_kfree_skb_any(skb);
 938                 return NETDEV_TX_OK;
 939         }
 940
 941         /* Don't wait up for transmitted skbs to be freed. */
 942         skb_orphan(skb);
 943         nf_reset(skb);
 944
 945         /* Apparently nice girls don't return TX_BUSY; stop the queue
 946          * before it gets out of hand.  Naturally, this wastes entries. */
 947         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
 948                 netif_stop_subqueue(dev, qnum);
 949                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 950                         /* More just got used, free them then recheck. */
 951                         free_old_xmit_skbs(sq);
 952                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
 953                                 netif_start_subqueue(dev, qnum);
 954                                 virtqueue_disable_cb(sq->vq);
 955                         }
 956                 }
 957         }
 958
 959         if (__netif_subqueue_stopped(dev, qnum) || !skb->xmit_more)
 960                 virtqueue_kick(sq->vq);
 961
 962         return NETDEV_TX_OK;
 963 }
 964
 965 /*
 966  * Send command via the control virtqueue and check status.  Commands
 967  * supported by the hypervisor, as indicated by feature bits, should
 968  * never fail unless improperly formatted.
 969  */
 970 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 971                                  struct scatterlist *out)
 972 {
 973         struct scatterlist *sgs[4], hdr, stat;
 974         struct virtio_net_ctrl_hdr ctrl;
 975         virtio_net_ctrl_ack status = ~0;
 976         unsigned out_num = 0, tmp;
 977
 978         /* Caller should know better */
 979         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
 980
 981         ctrl.class = class;
 982         ctrl.cmd = cmd;
 983         /* Add header */
 984         sg_init_one(&hdr, &ctrl, sizeof(ctrl));
 985         sgs[out_num++] = &hdr;
 986
 987         if (out)
 988                 sgs[out_num++] = out;
 989
 990         /* Add return status. */
 991         sg_init_one(&stat, &status, sizeof(status));
 992         sgs[out_num] = &stat;
 993
 994         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
 995         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
 996
 997         if (unlikely(!virtqueue_kick(vi->cvq)))
 998                 return status == VIRTIO_NET_OK;
 999
1000         /* Spin for a response, the kick causes an ioport write, trapping
1001          * into the hypervisor, so the request should be handled immediately.
1002          */
1003         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
1004                !virtqueue_is_broken(vi->cvq))
1005                 cpu_relax();
1006
1007         return status == VIRTIO_NET_OK;
1008 }
1009
1010 static int virtnet_set_mac_address(struct net_device *dev, void *p)
1011 {
1012         struct virtnet_info *vi = netdev_priv(dev);
1013         struct virtio_device *vdev = vi->vdev;
1014         int ret;
1015         struct sockaddr *addr = p;
1016         struct scatterlist sg;
1017
1018         ret = eth_prepare_mac_addr_change(dev, p);
1019         if (ret)
1020                 return ret;
1021
1022         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
1023                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
1024                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1025                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
1026                         dev_warn(&vdev->dev,
1027                                  "Failed to set mac address by vq command.\n");
1028                         return -EINVAL;
1029                 }
1030         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
1031                 unsigned int i;
1032
1033                 /* Naturally, this has an atomicity problem. */
1034                 for (i = 0; i < dev->addr_len; i++)
1035                         virtio_cwrite8(vdev,
1036                                        offsetof(struct virtio_net_config, mac) +
1037                                        i, addr->sa_data[i]);
1038         }
1039
1040         eth_commit_mac_addr_change(dev, p);
1041
1042         return 0;
1043 }
1044
1045 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
1046                                                struct rtnl_link_stats64 *tot)
1047 {
1048         struct virtnet_info *vi = netdev_priv(dev);
1049         int cpu;
1050         unsigned int start;
1051
1052         for_each_possible_cpu(cpu) {
1053                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1054                 u64 tpackets, tbytes, rpackets, rbytes;
1055
1056                 do {
1057                         start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
1058                         tpackets = stats->tx_packets;
1059                         tbytes   = stats->tx_bytes;
1060                 } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
1061
1062                 do {
1063                         start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
1064                         rpackets = stats->rx_packets;
1065                         rbytes   = stats->rx_bytes;
1066                 } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
1067
1068                 tot->rx_packets += rpackets;
1069                 tot->tx_packets += tpackets;
1070                 tot->rx_bytes   += rbytes;
1071                 tot->tx_bytes   += tbytes;
1072         }
1073
1074         tot->tx_dropped = dev->stats.tx_dropped;
1075         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1076         tot->rx_dropped = dev->stats.rx_dropped;
1077         tot->rx_length_errors = dev->stats.rx_length_errors;
1078         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1079
1080         return tot;
1081 }
1082
1083 #ifdef CONFIG_NET_POLL_CONTROLLER
1084 static void virtnet_netpoll(struct net_device *dev)
1085 {
1086         struct virtnet_info *vi = netdev_priv(dev);
1087         int i;
1088
1089         for (i = 0; i < vi->curr_queue_pairs; i++)
1090                 napi_schedule(&vi->rq[i].napi);
1091 }
1092 #endif
1093
1094 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1095 {
1096         rtnl_lock();
1097         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1098                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1099                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1100         rtnl_unlock();
1101 }
1102
1103 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1104 {
1105         struct scatterlist sg;
1106         struct virtio_net_ctrl_mq s;
1107         struct net_device *dev = vi->dev;
1108
1109         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1110                 return 0;
1111
1112         s.virtqueue_pairs = queue_pairs;
1113         sg_init_one(&sg, &s, sizeof(s));
1114
1115         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1116                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1117                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1118                          queue_pairs);
1119                 return -EINVAL;
1120         } else {
1121                 vi->curr_queue_pairs = queue_pairs;
1122                 /* virtnet_open() will refill when device is going to up. */
1123                 if (dev->flags & IFF_UP)
1124                         schedule_delayed_work(&vi->refill, 0);
1125         }
1126
1127         return 0;
1128 }
1129
1130 static int virtnet_close(struct net_device *dev)
1131 {
1132         struct virtnet_info *vi = netdev_priv(dev);
1133         int i;
1134
1135         /* Make sure refill_work doesn't re-enable napi! */
1136         cancel_delayed_work_sync(&vi->refill);
1137
1138         for (i = 0; i < vi->max_queue_pairs; i++)
1139                 napi_disable(&vi->rq[i].napi);
1140
1141         return 0;
1142 }
1143
1144 static void virtnet_set_rx_mode(struct net_device *dev)
1145 {
1146         struct virtnet_info *vi = netdev_priv(dev);
1147         struct scatterlist sg[2];
1148         u8 promisc, allmulti;
1149         struct virtio_net_ctrl_mac *mac_data;
1150         struct netdev_hw_addr *ha;
1151         int uc_count;
1152         int mc_count;
1153         void *buf;
1154         int i;
1155
1156         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1157         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1158                 return;
1159
1160         promisc = ((dev->flags & IFF_PROMISC) != 0);
1161         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1162
1163         sg_init_one(sg, &promisc, sizeof(promisc));
1164
1165         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1166                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1167                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1168                          promisc ? "en" : "dis");
1169
1170         sg_init_one(sg, &allmulti, sizeof(allmulti));
1171
1172         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1173                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1174                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1175                          allmulti ? "en" : "dis");
1176
1177         uc_count = netdev_uc_count(dev);
1178         mc_count = netdev_mc_count(dev);
1179         /* MAC filter - use one buffer for both lists */
1180         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1181                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1182         mac_data = buf;
1183         if (!buf)
1184                 return;
1185
1186         sg_init_table(sg, 2);
1187
1188         /* Store the unicast list and count in the front of the buffer */
1189         mac_data->entries = uc_count;
1190         i = 0;
1191         netdev_for_each_uc_addr(ha, dev)
1192                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1193
1194         sg_set_buf(&sg[0], mac_data,
1195                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1196
1197         /* multicast list and count fill the end */
1198         mac_data = (void *)&mac_data->macs[uc_count][0];
1199
1200         mac_data->entries = mc_count;
1201         i = 0;
1202         netdev_for_each_mc_addr(ha, dev)
1203                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1204
1205         sg_set_buf(&sg[1], mac_data,
1206                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1207
1208         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1209                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1210                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1211
1212         kfree(buf);
1213 }
1214
1215 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1216                                    __be16 proto, u16 vid)
1217 {
1218         struct virtnet_info *vi = netdev_priv(dev);
1219         struct scatterlist sg;
1220
1221         sg_init_one(&sg, &vid, sizeof(vid));
1222
1223         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1224                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1225                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1226         return 0;
1227 }
1228
1229 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1230                                     __be16 proto, u16 vid)
1231 {
1232         struct virtnet_info *vi = netdev_priv(dev);
1233         struct scatterlist sg;
1234
1235         sg_init_one(&sg, &vid, sizeof(vid));
1236
1237         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1238                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1239                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1240         return 0;
1241 }
1242
1243 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1244 {
1245         int i;
1246
1247         if (vi->affinity_hint_set) {
1248                 for (i = 0; i < vi->max_queue_pairs; i++) {
1249                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1250                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1251                 }
1252
1253                 vi->affinity_hint_set = false;
1254         }
1255 }
1256
1257 static void virtnet_set_affinity(struct virtnet_info *vi)
1258 {
1259         int i;
1260         int cpu;
1261
1262         /* In multiqueue mode, when the number of cpu is equal to the number of
1263          * queue pairs, we let the queue pairs to be private to one cpu by
1264          * setting the affinity hint to eliminate the contention.
1265          */
1266         if (vi->curr_queue_pairs == 1 ||
1267             vi->max_queue_pairs != num_online_cpus()) {
1268                 virtnet_clean_affinity(vi, -1);
1269                 return;
1270         }
1271
1272         i = 0;
1273         for_each_online_cpu(cpu) {
1274                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1275                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1276                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1277                 i++;
1278         }
1279
1280         vi->affinity_hint_set = true;
1281 }
1282
1283 static int virtnet_cpu_callback(struct notifier_block *nfb,
1284                                 unsigned long action, void *hcpu)
1285 {
1286         struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);
1287
1288         switch(action & ~CPU_TASKS_FROZEN) {
1289         case CPU_ONLINE:
1290         case CPU_DOWN_FAILED:
1291         case CPU_DEAD:
1292                 virtnet_set_affinity(vi);
1293                 break;
1294         case CPU_DOWN_PREPARE:
1295                 virtnet_clean_affinity(vi, (long)hcpu);
1296                 break;
1297         default:
1298                 break;
1299         }
1300
1301         return NOTIFY_OK;
1302 }
1303
1304 static void virtnet_get_ringparam(struct net_device *dev,
1305                                 struct ethtool_ringparam *ring)
1306 {
1307         struct virtnet_info *vi = netdev_priv(dev);
1308
1309         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1310         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1311         ring->rx_pending = ring->rx_max_pending;
1312         ring->tx_pending = ring->tx_max_pending;
1313 }
1314
1315
1316 static void virtnet_get_drvinfo(struct net_device *dev,
1317                                 struct ethtool_drvinfo *info)
1318 {
1319         struct virtnet_info *vi = netdev_priv(dev);
1320         struct virtio_device *vdev = vi->vdev;
1321
1322         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1323         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1324         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1325
1326 }
1327
1328 /* TODO: Eliminate OOO packets during switching */
1329 static int virtnet_set_channels(struct net_device *dev,
1330                                 struct ethtool_channels *channels)
1331 {
1332         struct virtnet_info *vi = netdev_priv(dev);
1333         u16 queue_pairs = channels->combined_count;
1334         int err;
1335
1336         /* We don't support separate rx/tx channels.
1337          * We don't allow setting 'other' channels.
1338          */
1339         if (channels->rx_count || channels->tx_count || channels->other_count)
1340                 return -EINVAL;
1341
1342         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1343                 return -EINVAL;
1344
1345         get_online_cpus();
1346         err = virtnet_set_queues(vi, queue_pairs);
1347         if (!err) {
1348                 netif_set_real_num_tx_queues(dev, queue_pairs);
1349                 netif_set_real_num_rx_queues(dev, queue_pairs);
1350
1351                 virtnet_set_affinity(vi);
1352         }
1353         put_online_cpus();
1354
1355         return err;
1356 }
1357
1358 static void virtnet_get_channels(struct net_device *dev,
1359                                  struct ethtool_channels *channels)
1360 {
1361         struct virtnet_info *vi = netdev_priv(dev);
1362
1363         channels->combined_count = vi->curr_queue_pairs;
1364         channels->max_combined = vi->max_queue_pairs;
1365         channels->max_other = 0;
1366         channels->rx_count = 0;
1367         channels->tx_count = 0;
1368         channels->other_count = 0;
1369 }
1370
1371 static const struct ethtool_ops virtnet_ethtool_ops = {
1372         .get_drvinfo = virtnet_get_drvinfo,
1373         .get_link = ethtool_op_get_link,
1374         .get_ringparam = virtnet_get_ringparam,
1375         .set_channels = virtnet_set_channels,
1376         .get_channels = virtnet_get_channels,
1377 };
1378
1379 #define MIN_MTU 68
1380 #define MAX_MTU 65535
1381
1382 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1383 {
1384         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1385                 return -EINVAL;
1386         dev->mtu = new_mtu;
1387         return 0;
1388 }
1389
1390 static const struct net_device_ops virtnet_netdev = {
1391         .ndo_open            = virtnet_open,
1392         .ndo_stop            = virtnet_close,
1393         .ndo_start_xmit      = start_xmit,
1394         .ndo_validate_addr   = eth_validate_addr,
1395         .ndo_set_mac_address = virtnet_set_mac_address,
1396         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1397         .ndo_change_mtu      = virtnet_change_mtu,
1398         .ndo_get_stats64     = virtnet_stats,
1399         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1400         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1401 #ifdef CONFIG_NET_POLL_CONTROLLER
1402         .ndo_poll_controller = virtnet_netpoll,
1403 #endif
1404 #ifdef CONFIG_NET_RX_BUSY_POLL
1405         .ndo_busy_poll          = virtnet_busy_poll,
1406 #endif
1407 };
1408
1409 static void virtnet_config_changed_work(struct work_struct *work)
1410 {
1411         struct virtnet_info *vi =
1412                 container_of(work, struct virtnet_info, config_work);
1413         u16 v;
1414
1415         mutex_lock(&vi->config_lock);
1416         if (!vi->config_enable)
1417                 goto done;
1418
1419         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
1420                                  struct virtio_net_config, status, &v) < 0)
1421                 goto done;
1422
1423         if (v & VIRTIO_NET_S_ANNOUNCE) {
1424                 netdev_notify_peers(vi->dev);
1425                 virtnet_ack_link_announce(vi);
1426         }
1427
1428         /* Ignore unknown (future) status bits */
1429         v &= VIRTIO_NET_S_LINK_UP;
1430
1431         if (vi->status == v)
1432                 goto done;
1433
1434         vi->status = v;
1435
1436         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1437                 netif_carrier_on(vi->dev);
1438                 netif_tx_wake_all_queues(vi->dev);
1439         } else {
1440                 netif_carrier_off(vi->dev);
1441                 netif_tx_stop_all_queues(vi->dev);
1442         }
1443 done:
1444         mutex_unlock(&vi->config_lock);
1445 }
1446
1447 static void virtnet_config_changed(struct virtio_device *vdev)
1448 {
1449         struct virtnet_info *vi = vdev->priv;
1450
1451         schedule_work(&vi->config_work);
1452 }
1453
1454 static void virtnet_free_queues(struct virtnet_info *vi)
1455 {
1456         int i;
1457
1458         for (i = 0; i < vi->max_queue_pairs; i++)
1459                 netif_napi_del(&vi->rq[i].napi);
1460
1461         kfree(vi->rq);
1462         kfree(vi->sq);
1463 }
1464
1465 static void free_receive_bufs(struct virtnet_info *vi)
1466 {
1467         int i;
1468
1469         for (i = 0; i < vi->max_queue_pairs; i++) {
1470                 while (vi->rq[i].pages)
1471                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1472         }
1473 }
1474
1475 static void free_receive_page_frags(struct virtnet_info *vi)
1476 {
1477         int i;
1478         for (i = 0; i < vi->max_queue_pairs; i++)
1479                 if (vi->rq[i].alloc_frag.page)
1480                         put_page(vi->rq[i].alloc_frag.page);
1481 }
1482
1483 static void free_unused_bufs(struct virtnet_info *vi)
1484 {
1485         void *buf;
1486         int i;
1487
1488         for (i = 0; i < vi->max_queue_pairs; i++) {
1489                 struct virtqueue *vq = vi->sq[i].vq;
1490                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1491                         dev_kfree_skb(buf);
1492         }
1493
1494         for (i = 0; i < vi->max_queue_pairs; i++) {
1495                 struct virtqueue *vq = vi->rq[i].vq;
1496
1497                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1498                         if (vi->mergeable_rx_bufs) {
1499                                 unsigned long ctx = (unsigned long)buf;
1500                                 void *base = mergeable_ctx_to_buf_address(ctx);
1501                                 put_page(virt_to_head_page(base));
1502                         } else if (vi->big_packets) {
1503                                 give_pages(&vi->rq[i], buf);
1504                         } else {
1505                                 dev_kfree_skb(buf);
1506                         }
1507                 }
1508         }
1509 }
1510
1511 static void virtnet_del_vqs(struct virtnet_info *vi)
1512 {
1513         struct virtio_device *vdev = vi->vdev;
1514
1515         virtnet_clean_affinity(vi, -1);
1516
1517         vdev->config->del_vqs(vdev);
1518
1519         virtnet_free_queues(vi);
1520 }
1521
1522 static int virtnet_find_vqs(struct virtnet_info *vi)
1523 {
1524         vq_callback_t **callbacks;
1525         struct virtqueue **vqs;
1526         int ret = -ENOMEM;
1527         int i, total_vqs;
1528         const char **names;
1529
1530         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1531          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1532          * possible control vq.
1533          */
1534         total_vqs = vi->max_queue_pairs * 2 +
1535                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1536
1537         /* Allocate space for find_vqs parameters */
1538         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1539         if (!vqs)
1540                 goto err_vq;
1541         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1542         if (!callbacks)
1543                 goto err_callback;
1544         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1545         if (!names)
1546                 goto err_names;
1547
1548         /* Parameters for control virtqueue, if any */
1549         if (vi->has_cvq) {
1550                 callbacks[total_vqs - 1] = NULL;
1551                 names[total_vqs - 1] = "control";
1552         }
1553
1554         /* Allocate/initialize parameters for send/receive virtqueues */
1555         for (i = 0; i < vi->max_queue_pairs; i++) {
1556                 callbacks[rxq2vq(i)] = skb_recv_done;
1557                 callbacks[txq2vq(i)] = skb_xmit_done;
1558                 sprintf(vi->rq[i].name, "input.%d", i);
1559                 sprintf(vi->sq[i].name, "output.%d", i);
1560                 names[rxq2vq(i)] = vi->rq[i].name;
1561                 names[txq2vq(i)] = vi->sq[i].name;
1562         }
1563
1564         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1565                                          names);
1566         if (ret)
1567                 goto err_find;
1568
1569         if (vi->has_cvq) {
1570                 vi->cvq = vqs[total_vqs - 1];
1571                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1572                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1573         }
1574
1575         for (i = 0; i < vi->max_queue_pairs; i++) {
1576                 vi->rq[i].vq = vqs[rxq2vq(i)];
1577                 vi->sq[i].vq = vqs[txq2vq(i)];
1578         }
1579
1580         kfree(names);
1581         kfree(callbacks);
1582         kfree(vqs);
1583
1584         return 0;
1585
1586 err_find:
1587         kfree(names);
1588 err_names:
1589         kfree(callbacks);
1590 err_callback:
1591         kfree(vqs);
1592 err_vq:
1593         return ret;
1594 }
1595
1596 static int virtnet_alloc_queues(struct virtnet_info *vi)
1597 {
1598         int i;
1599
1600         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1601         if (!vi->sq)
1602                 goto err_sq;
1603         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1604         if (!vi->rq)
1605                 goto err_rq;
1606
1607         INIT_DELAYED_WORK(&vi->refill, refill_work);
1608         for (i = 0; i < vi->max_queue_pairs; i++) {
1609                 vi->rq[i].pages = NULL;
1610                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1611                                napi_weight);
1612                 napi_hash_add(&vi->rq[i].napi);
1613
1614                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1615                 ewma_init(&vi->rq[i].mrg_avg_pkt_len, 1, RECEIVE_AVG_WEIGHT);
1616                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1617         }
1618
1619         return 0;
1620
1621 err_rq:
1622         kfree(vi->sq);
1623 err_sq:
1624         return -ENOMEM;
1625 }
1626
1627 static int init_vqs(struct virtnet_info *vi)
1628 {
1629         int ret;
1630
1631         /* Allocate send & receive queues */
1632         ret = virtnet_alloc_queues(vi);
1633         if (ret)
1634                 goto err;
1635
1636         ret = virtnet_find_vqs(vi);
1637         if (ret)
1638                 goto err_free;
1639
1640         get_online_cpus();
1641         virtnet_set_affinity(vi);
1642         put_online_cpus();
1643
1644         return 0;
1645
1646 err_free:
1647         virtnet_free_queues(vi);
1648 err:
1649         return ret;
1650 }
1651
1652 #ifdef CONFIG_SYSFS
1653 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
1654                 struct rx_queue_attribute *attribute, char *buf)
1655 {
1656         struct virtnet_info *vi = netdev_priv(queue->dev);
1657         unsigned int queue_index = get_netdev_rx_queue_index(queue);
1658         struct ewma *avg;
1659
1660         BUG_ON(queue_index >= vi->max_queue_pairs);
1661         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
1662         return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
1663 }
1664
1665 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
1666         __ATTR_RO(mergeable_rx_buffer_size);
1667
1668 static struct attribute *virtio_net_mrg_rx_attrs[] = {
1669         &mergeable_rx_buffer_size_attribute.attr,
1670         NULL
1671 };
1672
1673 static const struct attribute_group virtio_net_mrg_rx_group = {
1674         .name = "virtio_net",
1675         .attrs = virtio_net_mrg_rx_attrs
1676 };
1677 #endif
1678
1679 static int virtnet_probe(struct virtio_device *vdev)
1680 {
1681         int i, err;
1682         struct net_device *dev;
1683         struct virtnet_info *vi;
1684         u16 max_queue_pairs;
1685
1686         /* Find if host supports multiqueue virtio_net device */
1687         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
1688                                    struct virtio_net_config,
1689                                    max_virtqueue_pairs, &max_queue_pairs);
1690
1691         /* We need at least 2 queue's */
1692         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1693             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1694             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1695                 max_queue_pairs = 1;
1696
1697         /* Allocate ourselves a network device with room for our info */
1698         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1699         if (!dev)
1700                 return -ENOMEM;
1701
1702         /* Set up network device as normal. */
1703         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1704         dev->netdev_ops = &virtnet_netdev;
1705         dev->features = NETIF_F_HIGHDMA;
1706
1707         dev->ethtool_ops = &virtnet_ethtool_ops;
1708         SET_NETDEV_DEV(dev, &vdev->dev);
1709
1710         /* Do we support "hardware" checksums? */
1711         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1712                 /* This opens up the world of extra features. */
1713                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1714                 if (csum)
1715                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1716
1717                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1718                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1719                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1720                 }
1721                 /* Individual feature bits: what can host handle? */
1722                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1723                         dev->hw_features |= NETIF_F_TSO;
1724                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1725                         dev->hw_features |= NETIF_F_TSO6;
1726                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1727                         dev->hw_features |= NETIF_F_TSO_ECN;
1728                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1729                         dev->hw_features |= NETIF_F_UFO;
1730
1731                 if (gso)
1732                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1733                 /* (!csum && gso) case will be fixed by register_netdev() */
1734         }
1735         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
1736                 dev->features |= NETIF_F_RXCSUM;
1737
1738         dev->vlan_features = dev->features;
1739
1740         /* Configuration may specify what MAC to use.  Otherwise random. */
1741         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
1742                 virtio_cread_bytes(vdev,
1743                                    offsetof(struct virtio_net_config, mac),
1744                                    dev->dev_addr, dev->addr_len);
1745         else
1746                 eth_hw_addr_random(dev);
1747
1748         /* Set up our device-specific information */
1749         vi = netdev_priv(dev);
1750         vi->dev = dev;
1751         vi->vdev = vdev;
1752         vdev->priv = vi;
1753         vi->stats = alloc_percpu(struct virtnet_stats);
1754         err = -ENOMEM;
1755         if (vi->stats == NULL)
1756                 goto free;
1757
1758         for_each_possible_cpu(i) {
1759                 struct virtnet_stats *virtnet_stats;
1760                 virtnet_stats = per_cpu_ptr(vi->stats, i);
1761                 u64_stats_init(&virtnet_stats->tx_syncp);
1762                 u64_stats_init(&virtnet_stats->rx_syncp);
1763         }
1764
1765         mutex_init(&vi->config_lock);
1766         vi->config_enable = true;
1767         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1768
1769         /* If we can receive ANY GSO packets, we must allocate large ones. */
1770         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1771             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1772             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
1773             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
1774                 vi->big_packets = true;
1775
1776         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1777                 vi->mergeable_rx_bufs = true;
1778
1779         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT))
1780                 vi->any_header_sg = true;
1781
1782         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1783                 vi->has_cvq = true;
1784
1785         if (vi->any_header_sg) {
1786                 if (vi->mergeable_rx_bufs)
1787                         dev->needed_headroom = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1788                 else
1789                         dev->needed_headroom = sizeof(struct virtio_net_hdr);
1790         }
1791
1792         /* Use single tx/rx queue pair as default */
1793         vi->curr_queue_pairs = 1;
1794         vi->max_queue_pairs = max_queue_pairs;
1795
1796         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1797         err = init_vqs(vi);
1798         if (err)
1799                 goto free_stats;
1800
1801 #ifdef CONFIG_SYSFS
1802         if (vi->mergeable_rx_bufs)
1803                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
1804 #endif
1805         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
1806         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
1807
1808         err = register_netdev(dev);
1809         if (err) {
1810                 pr_debug("virtio_net: registering device failed\n");
1811                 goto free_vqs;
1812         }
1813
1814         /* Last of all, set up some receive buffers. */
1815         for (i = 0; i < vi->curr_queue_pairs; i++) {
1816                 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1817
1818                 /* If we didn't even get one input buffer, we're useless. */
1819                 if (vi->rq[i].vq->num_free ==
1820                     virtqueue_get_vring_size(vi->rq[i].vq)) {
1821                         free_unused_bufs(vi);
1822                         err = -ENOMEM;
1823                         goto free_recv_bufs;
1824                 }
1825         }
1826
1827         vi->nb.notifier_call = &virtnet_cpu_callback;
1828         err = register_hotcpu_notifier(&vi->nb);
1829         if (err) {
1830                 pr_debug("virtio_net: registering cpu notifier failed\n");
1831                 goto free_recv_bufs;
1832         }
1833
1834         /* Assume link up if device can't report link status,
1835            otherwise get link status from config. */
1836         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1837                 netif_carrier_off(dev);
1838                 schedule_work(&vi->config_work);
1839         } else {
1840                 vi->status = VIRTIO_NET_S_LINK_UP;
1841                 netif_carrier_on(dev);
1842         }
1843
1844         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1845                  dev->name, max_queue_pairs);
1846
1847         return 0;
1848
1849 free_recv_bufs:
1850         free_receive_bufs(vi);
1851         unregister_netdev(dev);
1852 free_vqs:
1853         cancel_delayed_work_sync(&vi->refill);
1854         free_receive_page_frags(vi);
1855         virtnet_del_vqs(vi);
1856 free_stats:
1857         free_percpu(vi->stats);
1858 free:
1859         free_netdev(dev);
1860         return err;
1861 }
1862
1863 static void remove_vq_common(struct virtnet_info *vi)
1864 {
1865         vi->vdev->config->reset(vi->vdev);
1866
1867         /* Free unused buffers in both send and recv, if any. */
1868         free_unused_bufs(vi);
1869
1870         free_receive_bufs(vi);
1871
1872         free_receive_page_frags(vi);
1873
1874         virtnet_del_vqs(vi);
1875 }
1876
1877 static void virtnet_remove(struct virtio_device *vdev)
1878 {
1879         struct virtnet_info *vi = vdev->priv;
1880
1881         unregister_hotcpu_notifier(&vi->nb);
1882
1883         /* Prevent config work handler from accessing the device. */
1884         mutex_lock(&vi->config_lock);
1885         vi->config_enable = false;
1886         mutex_unlock(&vi->config_lock);
1887
1888         unregister_netdev(vi->dev);
1889
1890         remove_vq_common(vi);
1891
1892         flush_work(&vi->config_work);
1893
1894         free_percpu(vi->stats);
1895         free_netdev(vi->dev);
1896 }
1897
1898 #ifdef CONFIG_PM_SLEEP
1899 static int virtnet_freeze(struct virtio_device *vdev)
1900 {
1901         struct virtnet_info *vi = vdev->priv;
1902         int i;
1903
1904         unregister_hotcpu_notifier(&vi->nb);
1905
1906         /* Prevent config work handler from accessing the device */
1907         mutex_lock(&vi->config_lock);
1908         vi->config_enable = false;
1909         mutex_unlock(&vi->config_lock);
1910
1911         netif_device_detach(vi->dev);
1912         cancel_delayed_work_sync(&vi->refill);
1913
1914         if (netif_running(vi->dev)) {
1915                 for (i = 0; i < vi->max_queue_pairs; i++) {
1916                         napi_disable(&vi->rq[i].napi);
1917                         napi_hash_del(&vi->rq[i].napi);
1918                         netif_napi_del(&vi->rq[i].napi);
1919                 }
1920         }
1921
1922         remove_vq_common(vi);
1923
1924         flush_work(&vi->config_work);
1925
1926         return 0;
1927 }
1928
1929 static int virtnet_restore(struct virtio_device *vdev)
1930 {
1931         struct virtnet_info *vi = vdev->priv;
1932         int err, i;
1933
1934         err = init_vqs(vi);
1935         if (err)
1936                 return err;
1937
1938         if (netif_running(vi->dev)) {
1939                 for (i = 0; i < vi->curr_queue_pairs; i++)
1940                         if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1941                                 schedule_delayed_work(&vi->refill, 0);
1942
1943                 for (i = 0; i < vi->max_queue_pairs; i++)
1944                         virtnet_napi_enable(&vi->rq[i]);
1945         }
1946
1947         netif_device_attach(vi->dev);
1948
1949         mutex_lock(&vi->config_lock);
1950         vi->config_enable = true;
1951         mutex_unlock(&vi->config_lock);
1952
1953         rtnl_lock();
1954         virtnet_set_queues(vi, vi->curr_queue_pairs);
1955         rtnl_unlock();
1956
1957         err = register_hotcpu_notifier(&vi->nb);
1958         if (err)
1959                 return err;
1960
1961         return 0;
1962 }
1963 #endif
1964
1965 static struct virtio_device_id id_table[] = {
1966         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1967         { 0 },
1968 };
1969
1970 static unsigned int features[] = {
1971         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1972         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1973         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1974         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1975         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1976         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1977         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1978         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1979         VIRTIO_NET_F_CTRL_MAC_ADDR,
1980         VIRTIO_F_ANY_LAYOUT,
1981 };
1982
1983 static struct virtio_driver virtio_net_driver = {
1984         .feature_table = features,
1985         .feature_table_size = ARRAY_SIZE(features),
1986         .driver.name =  KBUILD_MODNAME,
1987         .driver.owner = THIS_MODULE,
1988         .id_table =     id_table,
1989         .probe =        virtnet_probe,
1990         .remove =       virtnet_remove,
1991         .config_changed = virtnet_config_changed,
1992 #ifdef CONFIG_PM_SLEEP
1993         .freeze =       virtnet_freeze,
1994         .restore =      virtnet_restore,
1995 #endif
1996 };
1997
1998 module_virtio_driver(virtio_net_driver);
1999
2000 MODULE_DEVICE_TABLE(virtio, id_table);
2001 MODULE_DESCRIPTION("Virtio network driver");
2002 MODULE_LICENSE("GPL");