drivers/net/virtio_net.c

   1 /* A network driver using virtio.
   2  *
   3  * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18 //#define DEBUG
  19 #include <linux/netdevice.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/ethtool.h>
  22 #include <linux/module.h>
  23 #include <linux/virtio.h>
  24 #include <linux/virtio_net.h>
  25 #include <linux/scatterlist.h>
  26 #include <linux/if_vlan.h>
  27 #include <linux/slab.h>
  28 #include <linux/cpu.h>
  29 #include <linux/average.h>
  30 #include <net/busy_poll.h>
  31
  32 static int napi_weight = NAPI_POLL_WEIGHT;
  33 module_param(napi_weight, int, 0444);
  34
  35 static bool csum = true, gso = true;
  36 module_param(csum, bool, 0444);
  37 module_param(gso, bool, 0444);
  38
  39 /* FIXME: MTU in config. */
  40 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  41 #define GOOD_COPY_LEN   128
  42
  43 /* RX packet size EWMA. The average packet size is used to determine the packet
  44  * buffer size when refilling RX rings. As the entire RX ring may be refilled
  45  * at once, the weight is chosen so that the EWMA will be insensitive to short-
  46  * term, transient changes in packet size.
  47  */
  48 DECLARE_EWMA(pkt_len, 1, 64)
  49
  50 /* Minimum alignment for mergeable packet buffers. */
  51 #define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
  52
  53 #define VIRTNET_DRIVER_VERSION "1.0.0"
  54
  55 struct virtnet_stats {
  56         struct u64_stats_sync tx_syncp;
  57         struct u64_stats_sync rx_syncp;
  58         u64 tx_bytes;
  59         u64 tx_packets;
  60
  61         u64 rx_bytes;
  62         u64 rx_packets;
  63 };
  64
  65 /* Internal representation of a send virtqueue */
  66 struct send_queue {
  67         /* Virtqueue associated with this send _queue */
  68         struct virtqueue *vq;
  69
  70         /* TX: fragments + linear part + virtio header */
  71         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  72
  73         /* Name of the send queue: output.$index */
  74         char name[40];
  75 };
  76
  77 /* Internal representation of a receive virtqueue */
  78 struct receive_queue {
  79         /* Virtqueue associated with this receive_queue */
  80         struct virtqueue *vq;
  81
  82         struct napi_struct napi;
  83
  84         /* Chain pages by the private ptr. */
  85         struct page *pages;
  86
  87         /* Average packet length for mergeable receive buffers. */
  88         struct ewma_pkt_len mrg_avg_pkt_len;
  89
  90         /* Page frag for packet buffer allocation. */
  91         struct page_frag alloc_frag;
  92
  93         /* RX: fragments + linear part + virtio header */
  94         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  95
  96         /* Name of this receive queue: input.$index */
  97         char name[40];
  98 };
  99
 100 struct virtnet_info {
 101         struct virtio_device *vdev;
 102         struct virtqueue *cvq;
 103         struct net_device *dev;
 104         struct send_queue *sq;
 105         struct receive_queue *rq;
 106         unsigned int status;
 107
 108         /* Max # of queue pairs supported by the device */
 109         u16 max_queue_pairs;
 110
 111         /* # of queue pairs currently used by the driver */
 112         u16 curr_queue_pairs;
 113
 114         /* I like... big packets and I cannot lie! */
 115         bool big_packets;
 116
 117         /* Host will merge rx buffers for big packets (shake it! shake it!) */
 118         bool mergeable_rx_bufs;
 119
 120         /* Has control virtqueue */
 121         bool has_cvq;
 122
 123         /* Host can handle any s/g split between our header and packet data */
 124         bool any_header_sg;
 125
 126         /* Packet virtio header size */
 127         u8 hdr_len;
 128
 129         /* Active statistics */
 130         struct virtnet_stats __percpu *stats;
 131
 132         /* Work struct for refilling if we run low on memory. */
 133         struct delayed_work refill;
 134
 135         /* Work struct for config space updates */
 136         struct work_struct config_work;
 137
 138         /* Does the affinity hint is set for virtqueues? */
 139         bool affinity_hint_set;
 140
 141         /* CPU hot plug notifier */
 142         struct notifier_block nb;
 143
 144         /* Control VQ buffers: protected by the rtnl lock */
 145         struct virtio_net_ctrl_hdr ctrl_hdr;
 146         virtio_net_ctrl_ack ctrl_status;
 147         u8 ctrl_promisc;
 148         u8 ctrl_allmulti;
 149
 150         /* Ethtool settings */
 151         u8 duplex;
 152         u32 speed;
 153 };
 154
 155 struct padded_vnet_hdr {
 156         struct virtio_net_hdr_mrg_rxbuf hdr;
 157         /*
 158          * hdr is in a separate sg buffer, and data sg buffer shares same page
 159          * with this header sg. This padding makes next sg 16 byte aligned
 160          * after the header.
 161          */
 162         char padding[4];
 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 virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 189 {
 190         return (struct virtio_net_hdr_mrg_rxbuf *)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 virtnet_info *vi,
 251                                    struct receive_queue *rq,
 252                                    struct page *page, unsigned int offset,
 253                                    unsigned int len, unsigned int truesize)
 254 {
 255         struct sk_buff *skb;
 256         struct virtio_net_hdr_mrg_rxbuf *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 = napi_alloc_skb(&rq->napi, GOOD_COPY_LEN);
 264         if (unlikely(!skb))
 265                 return NULL;
 266
 267         hdr = skb_vnet_hdr(skb);
 268
 269         hdr_len = vi->hdr_len;
 270         if (vi->mergeable_rx_bufs)
 271                 hdr_padded_len = sizeof *hdr;
 272         else
 273                 hdr_padded_len = sizeof(struct padded_vnet_hdr);
 274
 275         memcpy(hdr, p, hdr_len);
 276
 277         len -= hdr_len;
 278         offset += hdr_padded_len;
 279         p += hdr_padded_len;
 280
 281         copy = len;
 282         if (copy > skb_tailroom(skb))
 283                 copy = skb_tailroom(skb);
 284         memcpy(skb_put(skb, copy), p, copy);
 285
 286         len -= copy;
 287         offset += copy;
 288
 289         if (vi->mergeable_rx_bufs) {
 290                 if (len)
 291                         skb_add_rx_frag(skb, 0, page, offset, len, truesize);
 292                 else
 293                         put_page(page);
 294                 return skb;
 295         }
 296
 297         /*
 298          * Verify that we can indeed put this data into a skb.
 299          * This is here to handle cases when the device erroneously
 300          * tries to receive more than is possible. This is usually
 301          * the case of a broken device.
 302          */
 303         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 304                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 305                 dev_kfree_skb(skb);
 306                 return NULL;
 307         }
 308         BUG_ON(offset >= PAGE_SIZE);
 309         while (len) {
 310                 unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 311                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
 312                                 frag_size, truesize);
 313                 len -= frag_size;
 314                 page = (struct page *)page->private;
 315                 offset = 0;
 316         }
 317
 318         if (page)
 319                 give_pages(rq, page);
 320
 321         return skb;
 322 }
 323
 324 static struct sk_buff *receive_small(struct virtnet_info *vi, void *buf, unsigned int len)
 325 {
 326         struct sk_buff * skb = buf;
 327
 328         len -= vi->hdr_len;
 329         skb_trim(skb, len);
 330
 331         return skb;
 332 }
 333
 334 static struct sk_buff *receive_big(struct net_device *dev,
 335                                    struct virtnet_info *vi,
 336                                    struct receive_queue *rq,
 337                                    void *buf,
 338                                    unsigned int len)
 339 {
 340         struct page *page = buf;
 341         struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
 342
 343         if (unlikely(!skb))
 344                 goto err;
 345
 346         return skb;
 347
 348 err:
 349         dev->stats.rx_dropped++;
 350         give_pages(rq, page);
 351         return NULL;
 352 }
 353
 354 static struct sk_buff *receive_mergeable(struct net_device *dev,
 355                                          struct virtnet_info *vi,
 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 virtio_net_hdr_mrg_rxbuf *hdr = buf;
 362         u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->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(vi, rq, page, offset, len,
 368                                                truesize);
 369         struct sk_buff *curr_skb = head_skb;
 370
 371         if (unlikely(!curr_skb))
 372                 goto err_skb;
 373         while (--num_buf) {
 374                 int num_skb_frags;
 375
 376                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 377                 if (unlikely(!ctx)) {
 378                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
 379                                  dev->name, num_buf,
 380                                  virtio16_to_cpu(vi->vdev,
 381                                                  hdr->num_buffers));
 382                         dev->stats.rx_length_errors++;
 383                         goto err_buf;
 384                 }
 385
 386                 buf = mergeable_ctx_to_buf_address(ctx);
 387                 page = virt_to_head_page(buf);
 388
 389                 num_skb_frags = skb_shinfo(curr_skb)->nr_frags;
 390                 if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
 391                         struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);
 392
 393                         if (unlikely(!nskb))
 394                                 goto err_skb;
 395                         if (curr_skb == head_skb)
 396                                 skb_shinfo(curr_skb)->frag_list = nskb;
 397                         else
 398                                 curr_skb->next = nskb;
 399                         curr_skb = nskb;
 400                         head_skb->truesize += nskb->truesize;
 401                         num_skb_frags = 0;
 402                 }
 403                 truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 404                 if (curr_skb != head_skb) {
 405                         head_skb->data_len += len;
 406                         head_skb->len += len;
 407                         head_skb->truesize += truesize;
 408                 }
 409                 offset = buf - page_address(page);
 410                 if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {
 411                         put_page(page);
 412                         skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,
 413                                              len, truesize);
 414                 } else {
 415                         skb_add_rx_frag(curr_skb, num_skb_frags, page,
 416                                         offset, len, truesize);
 417                 }
 418         }
 419
 420         ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
 421         return head_skb;
 422
 423 err_skb:
 424         put_page(page);
 425         while (--num_buf) {
 426                 ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 427                 if (unlikely(!ctx)) {
 428                         pr_debug("%s: rx error: %d buffers missing\n",
 429                                  dev->name, num_buf);
 430                         dev->stats.rx_length_errors++;
 431                         break;
 432                 }
 433                 page = virt_to_head_page(mergeable_ctx_to_buf_address(ctx));
 434                 put_page(page);
 435         }
 436 err_buf:
 437         dev->stats.rx_dropped++;
 438         dev_kfree_skb(head_skb);
 439         return NULL;
 440 }
 441
 442 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 443                         void *buf, unsigned int len)
 444 {
 445         struct net_device *dev = vi->dev;
 446         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 447         struct sk_buff *skb;
 448         struct virtio_net_hdr_mrg_rxbuf *hdr;
 449
 450         if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
 451                 pr_debug("%s: short packet %i\n", dev->name, len);
 452                 dev->stats.rx_length_errors++;
 453                 if (vi->mergeable_rx_bufs) {
 454                         unsigned long ctx = (unsigned long)buf;
 455                         void *base = mergeable_ctx_to_buf_address(ctx);
 456                         put_page(virt_to_head_page(base));
 457                 } else if (vi->big_packets) {
 458                         give_pages(rq, buf);
 459                 } else {
 460                         dev_kfree_skb(buf);
 461                 }
 462                 return;
 463         }
 464
 465         if (vi->mergeable_rx_bufs)
 466                 skb = receive_mergeable(dev, vi, rq, (unsigned long)buf, len);
 467         else if (vi->big_packets)
 468                 skb = receive_big(dev, vi, rq, buf, len);
 469         else
 470                 skb = receive_small(vi, buf, len);
 471
 472         if (unlikely(!skb))
 473                 return;
 474
 475         hdr = skb_vnet_hdr(skb);
 476
 477         u64_stats_update_begin(&stats->rx_syncp);
 478         stats->rx_bytes += skb->len;
 479         stats->rx_packets++;
 480         u64_stats_update_end(&stats->rx_syncp);
 481
 482         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
 483                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 484
 485         if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
 486                                   virtio_is_little_endian(vi->vdev))) {
 487                 net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
 488                                      dev->name, hdr->hdr.gso_type,
 489                                      hdr->hdr.gso_size);
 490                 goto frame_err;
 491         }
 492
 493         skb->protocol = eth_type_trans(skb, dev);
 494         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 495                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 496
 497         napi_gro_receive(&rq->napi, skb);
 498         return;
 499
 500 frame_err:
 501         dev->stats.rx_frame_errors++;
 502         dev_kfree_skb(skb);
 503 }
 504
 505 static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 506                              gfp_t gfp)
 507 {
 508         struct sk_buff *skb;
 509         struct virtio_net_hdr_mrg_rxbuf *hdr;
 510         int err;
 511
 512         skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
 513         if (unlikely(!skb))
 514                 return -ENOMEM;
 515
 516         skb_put(skb, GOOD_PACKET_LEN);
 517
 518         hdr = skb_vnet_hdr(skb);
 519         sg_init_table(rq->sg, 2);
 520         sg_set_buf(rq->sg, hdr, vi->hdr_len);
 521         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 522
 523         err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
 524         if (err < 0)
 525                 dev_kfree_skb(skb);
 526
 527         return err;
 528 }
 529
 530 static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
 531                            gfp_t gfp)
 532 {
 533         struct page *first, *list = NULL;
 534         char *p;
 535         int i, err, offset;
 536
 537         sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
 538
 539         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 540         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 541                 first = get_a_page(rq, gfp);
 542                 if (!first) {
 543                         if (list)
 544                                 give_pages(rq, list);
 545                         return -ENOMEM;
 546                 }
 547                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
 548
 549                 /* chain new page in list head to match sg */
 550                 first->private = (unsigned long)list;
 551                 list = first;
 552         }
 553
 554         first = get_a_page(rq, gfp);
 555         if (!first) {
 556                 give_pages(rq, list);
 557                 return -ENOMEM;
 558         }
 559         p = page_address(first);
 560
 561         /* rq->sg[0], rq->sg[1] share the same page */
 562         /* a separated rq->sg[0] for header - required in case !any_header_sg */
 563         sg_set_buf(&rq->sg[0], p, vi->hdr_len);
 564
 565         /* rq->sg[1] for data packet, from offset */
 566         offset = sizeof(struct padded_vnet_hdr);
 567         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
 568
 569         /* chain first in list head */
 570         first->private = (unsigned long)list;
 571         err = virtqueue_add_inbuf(rq->vq, rq->sg, MAX_SKB_FRAGS + 2,
 572                                   first, gfp);
 573         if (err < 0)
 574                 give_pages(rq, first);
 575
 576         return err;
 577 }
 578
 579 static unsigned int get_mergeable_buf_len(struct ewma_pkt_len *avg_pkt_len)
 580 {
 581         const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 582         unsigned int len;
 583
 584         len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
 585                         GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
 586         return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
 587 }
 588
 589 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
 590 {
 591         struct page_frag *alloc_frag = &rq->alloc_frag;
 592         char *buf;
 593         unsigned long ctx;
 594         int err;
 595         unsigned int len, hole;
 596
 597         len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len);
 598         if (unlikely(!skb_page_frag_refill(len, alloc_frag, gfp)))
 599                 return -ENOMEM;
 600
 601         buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
 602         ctx = mergeable_buf_to_ctx(buf, len);
 603         get_page(alloc_frag->page);
 604         alloc_frag->offset += len;
 605         hole = alloc_frag->size - alloc_frag->offset;
 606         if (hole < len) {
 607                 /* To avoid internal fragmentation, if there is very likely not
 608                  * enough space for another buffer, add the remaining space to
 609                  * the current buffer. This extra space is not included in
 610                  * the truesize stored in ctx.
 611                  */
 612                 len += hole;
 613                 alloc_frag->offset += hole;
 614         }
 615
 616         sg_init_one(rq->sg, buf, len);
 617         err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, (void *)ctx, gfp);
 618         if (err < 0)
 619                 put_page(virt_to_head_page(buf));
 620
 621         return err;
 622 }
 623
 624 /*
 625  * Returns false if we couldn't fill entirely (OOM).
 626  *
 627  * Normally run in the receive path, but can also be run from ndo_open
 628  * before we're receiving packets, or from refill_work which is
 629  * careful to disable receiving (using napi_disable).
 630  */
 631 static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
 632                           gfp_t gfp)
 633 {
 634         int err;
 635         bool oom;
 636
 637         gfp |= __GFP_COLD;
 638         do {
 639                 if (vi->mergeable_rx_bufs)
 640                         err = add_recvbuf_mergeable(rq, gfp);
 641                 else if (vi->big_packets)
 642                         err = add_recvbuf_big(vi, rq, gfp);
 643                 else
 644                         err = add_recvbuf_small(vi, rq, gfp);
 645
 646                 oom = err == -ENOMEM;
 647                 if (err)
 648                         break;
 649         } while (rq->vq->num_free);
 650         virtqueue_kick(rq->vq);
 651         return !oom;
 652 }
 653
 654 static void skb_recv_done(struct virtqueue *rvq)
 655 {
 656         struct virtnet_info *vi = rvq->vdev->priv;
 657         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 658
 659         /* Schedule NAPI, Suppress further interrupts if successful. */
 660         if (napi_schedule_prep(&rq->napi)) {
 661                 virtqueue_disable_cb(rvq);
 662                 __napi_schedule(&rq->napi);
 663         }
 664 }
 665
 666 static void virtnet_napi_enable(struct receive_queue *rq)
 667 {
 668         napi_enable(&rq->napi);
 669
 670         /* If all buffers were filled by other side before we napi_enabled, we
 671          * won't get another interrupt, so process any outstanding packets
 672          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 673          * We synchronize against interrupts via NAPI_STATE_SCHED */
 674         if (napi_schedule_prep(&rq->napi)) {
 675                 virtqueue_disable_cb(rq->vq);
 676                 local_bh_disable();
 677                 __napi_schedule(&rq->napi);
 678                 local_bh_enable();
 679         }
 680 }
 681
 682 static void refill_work(struct work_struct *work)
 683 {
 684         struct virtnet_info *vi =
 685                 container_of(work, struct virtnet_info, refill.work);
 686         bool still_empty;
 687         int i;
 688
 689         for (i = 0; i < vi->curr_queue_pairs; i++) {
 690                 struct receive_queue *rq = &vi->rq[i];
 691
 692                 napi_disable(&rq->napi);
 693                 still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
 694                 virtnet_napi_enable(rq);
 695
 696                 /* In theory, this can happen: if we don't get any buffers in
 697                  * we will *never* try to fill again.
 698                  */
 699                 if (still_empty)
 700                         schedule_delayed_work(&vi->refill, HZ/2);
 701         }
 702 }
 703
 704 static int virtnet_receive(struct receive_queue *rq, int budget)
 705 {
 706         struct virtnet_info *vi = rq->vq->vdev->priv;
 707         unsigned int len, received = 0;
 708         void *buf;
 709
 710         while (received < budget &&
 711                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
 712                 receive_buf(vi, rq, buf, len);
 713                 received++;
 714         }
 715
 716         if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
 717                 if (!try_fill_recv(vi, rq, GFP_ATOMIC))
 718                         schedule_delayed_work(&vi->refill, 0);
 719         }
 720
 721         return received;
 722 }
 723
 724 static int virtnet_poll(struct napi_struct *napi, int budget)
 725 {
 726         struct receive_queue *rq =
 727                 container_of(napi, struct receive_queue, napi);
 728         unsigned int r, received;
 729
 730         received = virtnet_receive(rq, budget);
 731
 732         /* Out of packets? */
 733         if (received < budget) {
 734                 r = virtqueue_enable_cb_prepare(rq->vq);
 735                 napi_complete_done(napi, received);
 736                 if (unlikely(virtqueue_poll(rq->vq, r)) &&
 737                     napi_schedule_prep(napi)) {
 738                         virtqueue_disable_cb(rq->vq);
 739                         __napi_schedule(napi);
 740                 }
 741         }
 742
 743         return received;
 744 }
 745
 746 #ifdef CONFIG_NET_RX_BUSY_POLL
 747 /* must be called with local_bh_disable()d */
 748 static int virtnet_busy_poll(struct napi_struct *napi)
 749 {
 750         struct receive_queue *rq =
 751                 container_of(napi, struct receive_queue, napi);
 752         struct virtnet_info *vi = rq->vq->vdev->priv;
 753         int r, received = 0, budget = 4;
 754
 755         if (!(vi->status & VIRTIO_NET_S_LINK_UP))
 756                 return LL_FLUSH_FAILED;
 757
 758         if (!napi_schedule_prep(napi))
 759                 return LL_FLUSH_BUSY;
 760
 761         virtqueue_disable_cb(rq->vq);
 762
 763 again:
 764         received += virtnet_receive(rq, budget);
 765
 766         r = virtqueue_enable_cb_prepare(rq->vq);
 767         clear_bit(NAPI_STATE_SCHED, &napi->state);
 768         if (unlikely(virtqueue_poll(rq->vq, r)) &&
 769             napi_schedule_prep(napi)) {
 770                 virtqueue_disable_cb(rq->vq);
 771                 if (received < budget) {
 772                         budget -= received;
 773                         goto again;
 774                 } else {
 775                         __napi_schedule(napi);
 776                 }
 777         }
 778
 779         return received;
 780 }
 781 #endif  /* CONFIG_NET_RX_BUSY_POLL */
 782
 783 static int virtnet_open(struct net_device *dev)
 784 {
 785         struct virtnet_info *vi = netdev_priv(dev);
 786         int i;
 787
 788         for (i = 0; i < vi->max_queue_pairs; i++) {
 789                 if (i < vi->curr_queue_pairs)
 790                         /* Make sure we have some buffers: if oom use wq. */
 791                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
 792                                 schedule_delayed_work(&vi->refill, 0);
 793                 virtnet_napi_enable(&vi->rq[i]);
 794         }
 795
 796         return 0;
 797 }
 798
 799 static void free_old_xmit_skbs(struct send_queue *sq)
 800 {
 801         struct sk_buff *skb;
 802         unsigned int len;
 803         struct virtnet_info *vi = sq->vq->vdev->priv;
 804         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 805
 806         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 807                 pr_debug("Sent skb %p\n", skb);
 808
 809                 u64_stats_update_begin(&stats->tx_syncp);
 810                 stats->tx_bytes += skb->len;
 811                 stats->tx_packets++;
 812                 u64_stats_update_end(&stats->tx_syncp);
 813
 814                 dev_kfree_skb_any(skb);
 815         }
 816 }
 817
 818 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 819 {
 820         struct virtio_net_hdr_mrg_rxbuf *hdr;
 821         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 822         struct virtnet_info *vi = sq->vq->vdev->priv;
 823         unsigned num_sg;
 824         unsigned hdr_len = vi->hdr_len;
 825         bool can_push;
 826
 827         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 828
 829         can_push = vi->any_header_sg &&
 830                 !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
 831                 !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
 832         /* Even if we can, don't push here yet as this would skew
 833          * csum_start offset below. */
 834         if (can_push)
 835                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
 836         else
 837                 hdr = skb_vnet_hdr(skb);
 838
 839         if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
 840                                     virtio_is_little_endian(vi->vdev)))
 841                 BUG();
 842
 843         if (vi->mergeable_rx_bufs)
 844                 hdr->num_buffers = 0;
 845
 846         sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2));
 847         if (can_push) {
 848                 __skb_push(skb, hdr_len);
 849                 num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
 850                 /* Pull header back to avoid skew in tx bytes calculations. */
 851                 __skb_pull(skb, hdr_len);
 852         } else {
 853                 sg_set_buf(sq->sg, hdr, hdr_len);
 854                 num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
 855         }
 856         return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
 857 }
 858
 859 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 860 {
 861         struct virtnet_info *vi = netdev_priv(dev);
 862         int qnum = skb_get_queue_mapping(skb);
 863         struct send_queue *sq = &vi->sq[qnum];
 864         int err;
 865         struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
 866         bool kick = !skb->xmit_more;
 867
 868         /* Free up any pending old buffers before queueing new ones. */
 869         free_old_xmit_skbs(sq);
 870
 871         /* timestamp packet in software */
 872         skb_tx_timestamp(skb);
 873
 874         /* Try to transmit */
 875         err = xmit_skb(sq, skb);
 876
 877         /* This should not happen! */
 878         if (unlikely(err)) {
 879                 dev->stats.tx_fifo_errors++;
 880                 if (net_ratelimit())
 881                         dev_warn(&dev->dev,
 882                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
 883                 dev->stats.tx_dropped++;
 884                 dev_kfree_skb_any(skb);
 885                 return NETDEV_TX_OK;
 886         }
 887
 888         /* Don't wait up for transmitted skbs to be freed. */
 889         skb_orphan(skb);
 890         nf_reset(skb);
 891
 892         /* If running out of space, stop queue to avoid getting packets that we
 893          * are then unable to transmit.
 894          * An alternative would be to force queuing layer to requeue the skb by
 895          * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be
 896          * returned in a normal path of operation: it means that driver is not
 897          * maintaining the TX queue stop/start state properly, and causes
 898          * the stack to do a non-trivial amount of useless work.
 899          * Since most packets only take 1 or 2 ring slots, stopping the queue
 900          * early means 16 slots are typically wasted.
 901          */
 902         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
 903                 netif_stop_subqueue(dev, qnum);
 904                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 905                         /* More just got used, free them then recheck. */
 906                         free_old_xmit_skbs(sq);
 907                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
 908                                 netif_start_subqueue(dev, qnum);
 909                                 virtqueue_disable_cb(sq->vq);
 910                         }
 911                 }
 912         }
 913
 914         if (kick || netif_xmit_stopped(txq))
 915                 virtqueue_kick(sq->vq);
 916
 917         return NETDEV_TX_OK;
 918 }
 919
 920 /*
 921  * Send command via the control virtqueue and check status.  Commands
 922  * supported by the hypervisor, as indicated by feature bits, should
 923  * never fail unless improperly formatted.
 924  */
 925 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 926                                  struct scatterlist *out)
 927 {
 928         struct scatterlist *sgs[4], hdr, stat;
 929         unsigned out_num = 0, tmp;
 930
 931         /* Caller should know better */
 932         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
 933
 934         vi->ctrl_status = ~0;
 935         vi->ctrl_hdr.class = class;
 936         vi->ctrl_hdr.cmd = cmd;
 937         /* Add header */
 938         sg_init_one(&hdr, &vi->ctrl_hdr, sizeof(vi->ctrl_hdr));
 939         sgs[out_num++] = &hdr;
 940
 941         if (out)
 942                 sgs[out_num++] = out;
 943
 944         /* Add return status. */
 945         sg_init_one(&stat, &vi->ctrl_status, sizeof(vi->ctrl_status));
 946         sgs[out_num] = &stat;
 947
 948         BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
 949         virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
 950
 951         if (unlikely(!virtqueue_kick(vi->cvq)))
 952                 return vi->ctrl_status == VIRTIO_NET_OK;
 953
 954         /* Spin for a response, the kick causes an ioport write, trapping
 955          * into the hypervisor, so the request should be handled immediately.
 956          */
 957         while (!virtqueue_get_buf(vi->cvq, &tmp) &&
 958                !virtqueue_is_broken(vi->cvq))
 959                 cpu_relax();
 960
 961         return vi->ctrl_status == VIRTIO_NET_OK;
 962 }
 963
 964 static int virtnet_set_mac_address(struct net_device *dev, void *p)
 965 {
 966         struct virtnet_info *vi = netdev_priv(dev);
 967         struct virtio_device *vdev = vi->vdev;
 968         int ret;
 969         struct sockaddr *addr = p;
 970         struct scatterlist sg;
 971
 972         ret = eth_prepare_mac_addr_change(dev, p);
 973         if (ret)
 974                 return ret;
 975
 976         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
 977                 sg_init_one(&sg, addr->sa_data, dev->addr_len);
 978                 if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
 979                                           VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) {
 980                         dev_warn(&vdev->dev,
 981                                  "Failed to set mac address by vq command.\n");
 982                         return -EINVAL;
 983                 }
 984         } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
 985                    !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
 986                 unsigned int i;
 987
 988                 /* Naturally, this has an atomicity problem. */
 989                 for (i = 0; i < dev->addr_len; i++)
 990                         virtio_cwrite8(vdev,
 991                                        offsetof(struct virtio_net_config, mac) +
 992                                        i, addr->sa_data[i]);
 993         }
 994
 995         eth_commit_mac_addr_change(dev, p);
 996
 997         return 0;
 998 }
 999
1000 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
1001                                                struct rtnl_link_stats64 *tot)
1002 {
1003         struct virtnet_info *vi = netdev_priv(dev);
1004         int cpu;
1005         unsigned int start;
1006
1007         for_each_possible_cpu(cpu) {
1008                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
1009                 u64 tpackets, tbytes, rpackets, rbytes;
1010
1011                 do {
1012                         start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
1013                         tpackets = stats->tx_packets;
1014                         tbytes   = stats->tx_bytes;
1015                 } while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
1016
1017                 do {
1018                         start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
1019                         rpackets = stats->rx_packets;
1020                         rbytes   = stats->rx_bytes;
1021                 } while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
1022
1023                 tot->rx_packets += rpackets;
1024                 tot->tx_packets += tpackets;
1025                 tot->rx_bytes   += rbytes;
1026                 tot->tx_bytes   += tbytes;
1027         }
1028
1029         tot->tx_dropped = dev->stats.tx_dropped;
1030         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
1031         tot->rx_dropped = dev->stats.rx_dropped;
1032         tot->rx_length_errors = dev->stats.rx_length_errors;
1033         tot->rx_frame_errors = dev->stats.rx_frame_errors;
1034
1035         return tot;
1036 }
1037
1038 #ifdef CONFIG_NET_POLL_CONTROLLER
1039 static void virtnet_netpoll(struct net_device *dev)
1040 {
1041         struct virtnet_info *vi = netdev_priv(dev);
1042         int i;
1043
1044         for (i = 0; i < vi->curr_queue_pairs; i++)
1045                 napi_schedule(&vi->rq[i].napi);
1046 }
1047 #endif
1048
1049 static void virtnet_ack_link_announce(struct virtnet_info *vi)
1050 {
1051         rtnl_lock();
1052         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
1053                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL))
1054                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
1055         rtnl_unlock();
1056 }
1057
1058 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
1059 {
1060         struct scatterlist sg;
1061         struct virtio_net_ctrl_mq s;
1062         struct net_device *dev = vi->dev;
1063
1064         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
1065                 return 0;
1066
1067         s.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
1068         sg_init_one(&sg, &s, sizeof(s));
1069
1070         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
1071                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg)) {
1072                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
1073                          queue_pairs);
1074                 return -EINVAL;
1075         } else {
1076                 vi->curr_queue_pairs = queue_pairs;
1077                 /* virtnet_open() will refill when device is going to up. */
1078                 if (dev->flags & IFF_UP)
1079                         schedule_delayed_work(&vi->refill, 0);
1080         }
1081
1082         return 0;
1083 }
1084
1085 static int virtnet_close(struct net_device *dev)
1086 {
1087         struct virtnet_info *vi = netdev_priv(dev);
1088         int i;
1089
1090         /* Make sure refill_work doesn't re-enable napi! */
1091         cancel_delayed_work_sync(&vi->refill);
1092
1093         for (i = 0; i < vi->max_queue_pairs; i++)
1094                 napi_disable(&vi->rq[i].napi);
1095
1096         return 0;
1097 }
1098
1099 static void virtnet_set_rx_mode(struct net_device *dev)
1100 {
1101         struct virtnet_info *vi = netdev_priv(dev);
1102         struct scatterlist sg[2];
1103         struct virtio_net_ctrl_mac *mac_data;
1104         struct netdev_hw_addr *ha;
1105         int uc_count;
1106         int mc_count;
1107         void *buf;
1108         int i;
1109
1110         /* We can't dynamically set ndo_set_rx_mode, so return gracefully */
1111         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
1112                 return;
1113
1114         vi->ctrl_promisc = ((dev->flags & IFF_PROMISC) != 0);
1115         vi->ctrl_allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
1116
1117         sg_init_one(sg, &vi->ctrl_promisc, sizeof(vi->ctrl_promisc));
1118
1119         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1120                                   VIRTIO_NET_CTRL_RX_PROMISC, sg))
1121                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
1122                          vi->ctrl_promisc ? "en" : "dis");
1123
1124         sg_init_one(sg, &vi->ctrl_allmulti, sizeof(vi->ctrl_allmulti));
1125
1126         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
1127                                   VIRTIO_NET_CTRL_RX_ALLMULTI, sg))
1128                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
1129                          vi->ctrl_allmulti ? "en" : "dis");
1130
1131         uc_count = netdev_uc_count(dev);
1132         mc_count = netdev_mc_count(dev);
1133         /* MAC filter - use one buffer for both lists */
1134         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
1135                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
1136         mac_data = buf;
1137         if (!buf)
1138                 return;
1139
1140         sg_init_table(sg, 2);
1141
1142         /* Store the unicast list and count in the front of the buffer */
1143         mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
1144         i = 0;
1145         netdev_for_each_uc_addr(ha, dev)
1146                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1147
1148         sg_set_buf(&sg[0], mac_data,
1149                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
1150
1151         /* multicast list and count fill the end */
1152         mac_data = (void *)&mac_data->macs[uc_count][0];
1153
1154         mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
1155         i = 0;
1156         netdev_for_each_mc_addr(ha, dev)
1157                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
1158
1159         sg_set_buf(&sg[1], mac_data,
1160                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
1161
1162         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
1163                                   VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
1164                 dev_warn(&dev->dev, "Failed to set MAC filter table.\n");
1165
1166         kfree(buf);
1167 }
1168
1169 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
1170                                    __be16 proto, u16 vid)
1171 {
1172         struct virtnet_info *vi = netdev_priv(dev);
1173         struct scatterlist sg;
1174
1175         sg_init_one(&sg, &vid, sizeof(vid));
1176
1177         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1178                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg))
1179                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1180         return 0;
1181 }
1182
1183 static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
1184                                     __be16 proto, u16 vid)
1185 {
1186         struct virtnet_info *vi = netdev_priv(dev);
1187         struct scatterlist sg;
1188
1189         sg_init_one(&sg, &vid, sizeof(vid));
1190
1191         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1192                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg))
1193                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1194         return 0;
1195 }
1196
1197 static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
1198 {
1199         int i;
1200
1201         if (vi->affinity_hint_set) {
1202                 for (i = 0; i < vi->max_queue_pairs; i++) {
1203                         virtqueue_set_affinity(vi->rq[i].vq, -1);
1204                         virtqueue_set_affinity(vi->sq[i].vq, -1);
1205                 }
1206
1207                 vi->affinity_hint_set = false;
1208         }
1209 }
1210
1211 static void virtnet_set_affinity(struct virtnet_info *vi)
1212 {
1213         int i;
1214         int cpu;
1215
1216         /* In multiqueue mode, when the number of cpu is equal to the number of
1217          * queue pairs, we let the queue pairs to be private to one cpu by
1218          * setting the affinity hint to eliminate the contention.
1219          */
1220         if (vi->curr_queue_pairs == 1 ||
1221             vi->max_queue_pairs != num_online_cpus()) {
1222                 virtnet_clean_affinity(vi, -1);
1223                 return;
1224         }
1225
1226         i = 0;
1227         for_each_online_cpu(cpu) {
1228                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1229                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1230                 netif_set_xps_queue(vi->dev, cpumask_of(cpu), i);
1231                 i++;
1232         }
1233
1234         vi->affinity_hint_set = true;
1235 }
1236
1237 static int virtnet_cpu_callback(struct notifier_block *nfb,
1238                                 unsigned long action, void *hcpu)
1239 {
1240         struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);
1241
1242         switch(action & ~CPU_TASKS_FROZEN) {
1243         case CPU_ONLINE:
1244         case CPU_DOWN_FAILED:
1245         case CPU_DEAD:
1246                 virtnet_set_affinity(vi);
1247                 break;
1248         case CPU_DOWN_PREPARE:
1249                 virtnet_clean_affinity(vi, (long)hcpu);
1250                 break;
1251         default:
1252                 break;
1253         }
1254
1255         return NOTIFY_OK;
1256 }
1257
1258 static void virtnet_get_ringparam(struct net_device *dev,
1259                                 struct ethtool_ringparam *ring)
1260 {
1261         struct virtnet_info *vi = netdev_priv(dev);
1262
1263         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1264         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1265         ring->rx_pending = ring->rx_max_pending;
1266         ring->tx_pending = ring->tx_max_pending;
1267 }
1268
1269
1270 static void virtnet_get_drvinfo(struct net_device *dev,
1271                                 struct ethtool_drvinfo *info)
1272 {
1273         struct virtnet_info *vi = netdev_priv(dev);
1274         struct virtio_device *vdev = vi->vdev;
1275
1276         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1277         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1278         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1279
1280 }
1281
1282 /* TODO: Eliminate OOO packets during switching */
1283 static int virtnet_set_channels(struct net_device *dev,
1284                                 struct ethtool_channels *channels)
1285 {
1286         struct virtnet_info *vi = netdev_priv(dev);
1287         u16 queue_pairs = channels->combined_count;
1288         int err;
1289
1290         /* We don't support separate rx/tx channels.
1291          * We don't allow setting 'other' channels.
1292          */
1293         if (channels->rx_count || channels->tx_count || channels->other_count)
1294                 return -EINVAL;
1295
1296         if (queue_pairs > vi->max_queue_pairs || queue_pairs == 0)
1297                 return -EINVAL;
1298
1299         get_online_cpus();
1300         err = virtnet_set_queues(vi, queue_pairs);
1301         if (!err) {
1302                 netif_set_real_num_tx_queues(dev, queue_pairs);
1303                 netif_set_real_num_rx_queues(dev, queue_pairs);
1304
1305                 virtnet_set_affinity(vi);
1306         }
1307         put_online_cpus();
1308
1309         return err;
1310 }
1311
1312 static void virtnet_get_channels(struct net_device *dev,
1313                                  struct ethtool_channels *channels)
1314 {
1315         struct virtnet_info *vi = netdev_priv(dev);
1316
1317         channels->combined_count = vi->curr_queue_pairs;
1318         channels->max_combined = vi->max_queue_pairs;
1319         channels->max_other = 0;
1320         channels->rx_count = 0;
1321         channels->tx_count = 0;
1322         channels->other_count = 0;
1323 }
1324
1325 /* Check if the user is trying to change anything besides speed/duplex */
1326 static bool virtnet_validate_ethtool_cmd(const struct ethtool_cmd *cmd)
1327 {
1328         struct ethtool_cmd diff1 = *cmd;
1329         struct ethtool_cmd diff2 = {};
1330
1331         /* cmd is always set so we need to clear it, validate the port type
1332          * and also without autonegotiation we can ignore advertising
1333          */
1334         ethtool_cmd_speed_set(&diff1, 0);
1335         diff2.port = PORT_OTHER;
1336         diff1.advertising = 0;
1337         diff1.duplex = 0;
1338         diff1.cmd = 0;
1339
1340         return !memcmp(&diff1, &diff2, sizeof(diff1));
1341 }
1342
1343 static int virtnet_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1344 {
1345         struct virtnet_info *vi = netdev_priv(dev);
1346         u32 speed;
1347
1348         speed = ethtool_cmd_speed(cmd);
1349         /* don't allow custom speed and duplex */
1350         if (!ethtool_validate_speed(speed) ||
1351             !ethtool_validate_duplex(cmd->duplex) ||
1352             !virtnet_validate_ethtool_cmd(cmd))
1353                 return -EINVAL;
1354         vi->speed = speed;
1355         vi->duplex = cmd->duplex;
1356
1357         return 0;
1358 }
1359
1360 static int virtnet_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1361 {
1362         struct virtnet_info *vi = netdev_priv(dev);
1363
1364         ethtool_cmd_speed_set(cmd, vi->speed);
1365         cmd->duplex = vi->duplex;
1366         cmd->port = PORT_OTHER;
1367
1368         return 0;
1369 }
1370
1371 static void virtnet_init_settings(struct net_device *dev)
1372 {
1373         struct virtnet_info *vi = netdev_priv(dev);
1374
1375         vi->speed = SPEED_UNKNOWN;
1376         vi->duplex = DUPLEX_UNKNOWN;
1377 }
1378
1379 static const struct ethtool_ops virtnet_ethtool_ops = {
1380         .get_drvinfo = virtnet_get_drvinfo,
1381         .get_link = ethtool_op_get_link,
1382         .get_ringparam = virtnet_get_ringparam,
1383         .set_channels = virtnet_set_channels,
1384         .get_channels = virtnet_get_channels,
1385         .get_ts_info = ethtool_op_get_ts_info,
1386         .get_settings = virtnet_get_settings,
1387         .set_settings = virtnet_set_settings,
1388 };
1389
1390 #define MIN_MTU 68
1391 #define MAX_MTU 65535
1392
1393 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1394 {
1395         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1396                 return -EINVAL;
1397         dev->mtu = new_mtu;
1398         return 0;
1399 }
1400
1401 static const struct net_device_ops virtnet_netdev = {
1402         .ndo_open            = virtnet_open,
1403         .ndo_stop            = virtnet_close,
1404         .ndo_start_xmit      = start_xmit,
1405         .ndo_validate_addr   = eth_validate_addr,
1406         .ndo_set_mac_address = virtnet_set_mac_address,
1407         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1408         .ndo_change_mtu      = virtnet_change_mtu,
1409         .ndo_get_stats64     = virtnet_stats,
1410         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1411         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1412 #ifdef CONFIG_NET_POLL_CONTROLLER
1413         .ndo_poll_controller = virtnet_netpoll,
1414 #endif
1415 #ifdef CONFIG_NET_RX_BUSY_POLL
1416         .ndo_busy_poll          = virtnet_busy_poll,
1417 #endif
1418 };
1419
1420 static void virtnet_config_changed_work(struct work_struct *work)
1421 {
1422         struct virtnet_info *vi =
1423                 container_of(work, struct virtnet_info, config_work);
1424         u16 v;
1425
1426         if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
1427                                  struct virtio_net_config, status, &v) < 0)
1428                 return;
1429
1430         if (v & VIRTIO_NET_S_ANNOUNCE) {
1431                 netdev_notify_peers(vi->dev);
1432                 virtnet_ack_link_announce(vi);
1433         }
1434
1435         /* Ignore unknown (future) status bits */
1436         v &= VIRTIO_NET_S_LINK_UP;
1437
1438         if (vi->status == v)
1439                 return;
1440
1441         vi->status = v;
1442
1443         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1444                 netif_carrier_on(vi->dev);
1445                 netif_tx_wake_all_queues(vi->dev);
1446         } else {
1447                 netif_carrier_off(vi->dev);
1448                 netif_tx_stop_all_queues(vi->dev);
1449         }
1450 }
1451
1452 static void virtnet_config_changed(struct virtio_device *vdev)
1453 {
1454         struct virtnet_info *vi = vdev->priv;
1455
1456         schedule_work(&vi->config_work);
1457 }
1458
1459 static void virtnet_free_queues(struct virtnet_info *vi)
1460 {
1461         int i;
1462
1463         for (i = 0; i < vi->max_queue_pairs; i++) {
1464                 napi_hash_del(&vi->rq[i].napi);
1465                 netif_napi_del(&vi->rq[i].napi);
1466         }
1467
1468         kfree(vi->rq);
1469         kfree(vi->sq);
1470 }
1471
1472 static void free_receive_bufs(struct virtnet_info *vi)
1473 {
1474         int i;
1475
1476         for (i = 0; i < vi->max_queue_pairs; i++) {
1477                 while (vi->rq[i].pages)
1478                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1479         }
1480 }
1481
1482 static void free_receive_page_frags(struct virtnet_info *vi)
1483 {
1484         int i;
1485         for (i = 0; i < vi->max_queue_pairs; i++)
1486                 if (vi->rq[i].alloc_frag.page)
1487                         put_page(vi->rq[i].alloc_frag.page);
1488 }
1489
1490 static void free_unused_bufs(struct virtnet_info *vi)
1491 {
1492         void *buf;
1493         int i;
1494
1495         for (i = 0; i < vi->max_queue_pairs; i++) {
1496                 struct virtqueue *vq = vi->sq[i].vq;
1497                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1498                         dev_kfree_skb(buf);
1499         }
1500
1501         for (i = 0; i < vi->max_queue_pairs; i++) {
1502                 struct virtqueue *vq = vi->rq[i].vq;
1503
1504                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1505                         if (vi->mergeable_rx_bufs) {
1506                                 unsigned long ctx = (unsigned long)buf;
1507                                 void *base = mergeable_ctx_to_buf_address(ctx);
1508                                 put_page(virt_to_head_page(base));
1509                         } else if (vi->big_packets) {
1510                                 give_pages(&vi->rq[i], buf);
1511                         } else {
1512                                 dev_kfree_skb(buf);
1513                         }
1514                 }
1515         }
1516 }
1517
1518 static void virtnet_del_vqs(struct virtnet_info *vi)
1519 {
1520         struct virtio_device *vdev = vi->vdev;
1521
1522         virtnet_clean_affinity(vi, -1);
1523
1524         vdev->config->del_vqs(vdev);
1525
1526         virtnet_free_queues(vi);
1527 }
1528
1529 static int virtnet_find_vqs(struct virtnet_info *vi)
1530 {
1531         vq_callback_t **callbacks;
1532         struct virtqueue **vqs;
1533         int ret = -ENOMEM;
1534         int i, total_vqs;
1535         const char **names;
1536
1537         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1538          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1539          * possible control vq.
1540          */
1541         total_vqs = vi->max_queue_pairs * 2 +
1542                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1543
1544         /* Allocate space for find_vqs parameters */
1545         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1546         if (!vqs)
1547                 goto err_vq;
1548         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1549         if (!callbacks)
1550                 goto err_callback;
1551         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1552         if (!names)
1553                 goto err_names;
1554
1555         /* Parameters for control virtqueue, if any */
1556         if (vi->has_cvq) {
1557                 callbacks[total_vqs - 1] = NULL;
1558                 names[total_vqs - 1] = "control";
1559         }
1560
1561         /* Allocate/initialize parameters for send/receive virtqueues */
1562         for (i = 0; i < vi->max_queue_pairs; i++) {
1563                 callbacks[rxq2vq(i)] = skb_recv_done;
1564                 callbacks[txq2vq(i)] = skb_xmit_done;
1565                 sprintf(vi->rq[i].name, "input.%d", i);
1566                 sprintf(vi->sq[i].name, "output.%d", i);
1567                 names[rxq2vq(i)] = vi->rq[i].name;
1568                 names[txq2vq(i)] = vi->sq[i].name;
1569         }
1570
1571         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1572                                          names);
1573         if (ret)
1574                 goto err_find;
1575
1576         if (vi->has_cvq) {
1577                 vi->cvq = vqs[total_vqs - 1];
1578                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1579                         vi->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1580         }
1581
1582         for (i = 0; i < vi->max_queue_pairs; i++) {
1583                 vi->rq[i].vq = vqs[rxq2vq(i)];
1584                 vi->sq[i].vq = vqs[txq2vq(i)];
1585         }
1586
1587         kfree(names);
1588         kfree(callbacks);
1589         kfree(vqs);
1590
1591         return 0;
1592
1593 err_find:
1594         kfree(names);
1595 err_names:
1596         kfree(callbacks);
1597 err_callback:
1598         kfree(vqs);
1599 err_vq:
1600         return ret;
1601 }
1602
1603 static int virtnet_alloc_queues(struct virtnet_info *vi)
1604 {
1605         int i;
1606
1607         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1608         if (!vi->sq)
1609                 goto err_sq;
1610         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1611         if (!vi->rq)
1612                 goto err_rq;
1613
1614         INIT_DELAYED_WORK(&vi->refill, refill_work);
1615         for (i = 0; i < vi->max_queue_pairs; i++) {
1616                 vi->rq[i].pages = NULL;
1617                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1618                                napi_weight);
1619
1620                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1621                 ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
1622                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1623         }
1624
1625         return 0;
1626
1627 err_rq:
1628         kfree(vi->sq);
1629 err_sq:
1630         return -ENOMEM;
1631 }
1632
1633 static int init_vqs(struct virtnet_info *vi)
1634 {
1635         int ret;
1636
1637         /* Allocate send & receive queues */
1638         ret = virtnet_alloc_queues(vi);
1639         if (ret)
1640                 goto err;
1641
1642         ret = virtnet_find_vqs(vi);
1643         if (ret)
1644                 goto err_free;
1645
1646         get_online_cpus();
1647         virtnet_set_affinity(vi);
1648         put_online_cpus();
1649
1650         return 0;
1651
1652 err_free:
1653         virtnet_free_queues(vi);
1654 err:
1655         return ret;
1656 }
1657
1658 #ifdef CONFIG_SYSFS
1659 static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
1660                 struct rx_queue_attribute *attribute, char *buf)
1661 {
1662         struct virtnet_info *vi = netdev_priv(queue->dev);
1663         unsigned int queue_index = get_netdev_rx_queue_index(queue);
1664         struct ewma_pkt_len *avg;
1665
1666         BUG_ON(queue_index >= vi->max_queue_pairs);
1667         avg = &vi->rq[queue_index].mrg_avg_pkt_len;
1668         return sprintf(buf, "%u\n", get_mergeable_buf_len(avg));
1669 }
1670
1671 static struct rx_queue_attribute mergeable_rx_buffer_size_attribute =
1672         __ATTR_RO(mergeable_rx_buffer_size);
1673
1674 static struct attribute *virtio_net_mrg_rx_attrs[] = {
1675         &mergeable_rx_buffer_size_attribute.attr,
1676         NULL
1677 };
1678
1679 static const struct attribute_group virtio_net_mrg_rx_group = {
1680         .name = "virtio_net",
1681         .attrs = virtio_net_mrg_rx_attrs
1682 };
1683 #endif
1684
1685 static bool virtnet_fail_on_feature(struct virtio_device *vdev,
1686                                     unsigned int fbit,
1687                                     const char *fname, const char *dname)
1688 {
1689         if (!virtio_has_feature(vdev, fbit))
1690                 return false;
1691
1692         dev_err(&vdev->dev, "device advertises feature %s but not %s",
1693                 fname, dname);
1694
1695         return true;
1696 }
1697
1698 #define VIRTNET_FAIL_ON(vdev, fbit, dbit)                       \
1699         virtnet_fail_on_feature(vdev, fbit, #fbit, dbit)
1700
1701 static bool virtnet_validate_features(struct virtio_device *vdev)
1702 {
1703         if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
1704             (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
1705                              "VIRTIO_NET_F_CTRL_VQ") ||
1706              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
1707                              "VIRTIO_NET_F_CTRL_VQ") ||
1708              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
1709                              "VIRTIO_NET_F_CTRL_VQ") ||
1710              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
1711              VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
1712                              "VIRTIO_NET_F_CTRL_VQ"))) {
1713                 return false;
1714         }
1715
1716         return true;
1717 }
1718
1719 static int virtnet_probe(struct virtio_device *vdev)
1720 {
1721         int i, err;
1722         struct net_device *dev;
1723         struct virtnet_info *vi;
1724         u16 max_queue_pairs;
1725         int mtu;
1726
1727         if (!vdev->config->get) {
1728                 dev_err(&vdev->dev, "%s failure: config access disabled\n",
1729                         __func__);
1730                 return -EINVAL;
1731         }
1732
1733         if (!virtnet_validate_features(vdev))
1734                 return -EINVAL;
1735
1736         /* Find if host supports multiqueue virtio_net device */
1737         err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
1738                                    struct virtio_net_config,
1739                                    max_virtqueue_pairs, &max_queue_pairs);
1740
1741         /* We need at least 2 queue's */
1742         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1743             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1744             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1745                 max_queue_pairs = 1;
1746
1747         /* Allocate ourselves a network device with room for our info */
1748         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1749         if (!dev)
1750                 return -ENOMEM;
1751
1752         /* Set up network device as normal. */
1753         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1754         dev->netdev_ops = &virtnet_netdev;
1755         dev->features = NETIF_F_HIGHDMA;
1756
1757         dev->ethtool_ops = &virtnet_ethtool_ops;
1758         SET_NETDEV_DEV(dev, &vdev->dev);
1759
1760         /* Do we support "hardware" checksums? */
1761         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1762                 /* This opens up the world of extra features. */
1763                 dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
1764                 if (csum)
1765                         dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
1766
1767                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1768                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1769                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1770                 }
1771                 /* Individual feature bits: what can host handle? */
1772                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1773                         dev->hw_features |= NETIF_F_TSO;
1774                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1775                         dev->hw_features |= NETIF_F_TSO6;
1776                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1777                         dev->hw_features |= NETIF_F_TSO_ECN;
1778                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1779                         dev->hw_features |= NETIF_F_UFO;
1780
1781                 dev->features |= NETIF_F_GSO_ROBUST;
1782
1783                 if (gso)
1784                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1785                 /* (!csum && gso) case will be fixed by register_netdev() */
1786         }
1787         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
1788                 dev->features |= NETIF_F_RXCSUM;
1789
1790         dev->vlan_features = dev->features;
1791
1792         /* Configuration may specify what MAC to use.  Otherwise random. */
1793         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
1794                 virtio_cread_bytes(vdev,
1795                                    offsetof(struct virtio_net_config, mac),
1796                                    dev->dev_addr, dev->addr_len);
1797         else
1798                 eth_hw_addr_random(dev);
1799
1800         /* Set up our device-specific information */
1801         vi = netdev_priv(dev);
1802         vi->dev = dev;
1803         vi->vdev = vdev;
1804         vdev->priv = vi;
1805         vi->stats = alloc_percpu(struct virtnet_stats);
1806         err = -ENOMEM;
1807         if (vi->stats == NULL)
1808                 goto free;
1809
1810         for_each_possible_cpu(i) {
1811                 struct virtnet_stats *virtnet_stats;
1812                 virtnet_stats = per_cpu_ptr(vi->stats, i);
1813                 u64_stats_init(&virtnet_stats->tx_syncp);
1814                 u64_stats_init(&virtnet_stats->rx_syncp);
1815         }
1816
1817         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1818
1819         /* If we can receive ANY GSO packets, we must allocate large ones. */
1820         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1821             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1822             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
1823             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
1824                 vi->big_packets = true;
1825
1826         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1827                 vi->mergeable_rx_bufs = true;
1828
1829         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
1830             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
1831                 vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1832         else
1833                 vi->hdr_len = sizeof(struct virtio_net_hdr);
1834
1835         if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) ||
1836             virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
1837                 vi->any_header_sg = true;
1838
1839         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1840                 vi->has_cvq = true;
1841
1842         if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) {
1843                 mtu = virtio_cread16(vdev,
1844                                      offsetof(struct virtio_net_config,
1845                                               mtu));
1846                 if (virtnet_change_mtu(dev, mtu))
1847                         __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
1848         }
1849
1850         if (vi->any_header_sg)
1851                 dev->needed_headroom = vi->hdr_len;
1852
1853         /* Use single tx/rx queue pair as default */
1854         vi->curr_queue_pairs = 1;
1855         vi->max_queue_pairs = max_queue_pairs;
1856
1857         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1858         err = init_vqs(vi);
1859         if (err)
1860                 goto free_stats;
1861
1862 #ifdef CONFIG_SYSFS
1863         if (vi->mergeable_rx_bufs)
1864                 dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group;
1865 #endif
1866         netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
1867         netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
1868
1869         virtnet_init_settings(dev);
1870
1871         err = register_netdev(dev);
1872         if (err) {
1873                 pr_debug("virtio_net: registering device failed\n");
1874                 goto free_vqs;
1875         }
1876
1877         virtio_device_ready(vdev);
1878
1879         vi->nb.notifier_call = &virtnet_cpu_callback;
1880         err = register_hotcpu_notifier(&vi->nb);
1881         if (err) {
1882                 pr_debug("virtio_net: registering cpu notifier failed\n");
1883                 goto free_unregister_netdev;
1884         }
1885
1886         /* Assume link up if device can't report link status,
1887            otherwise get link status from config. */
1888         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1889                 netif_carrier_off(dev);
1890                 schedule_work(&vi->config_work);
1891         } else {
1892                 vi->status = VIRTIO_NET_S_LINK_UP;
1893                 netif_carrier_on(dev);
1894         }
1895
1896         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1897                  dev->name, max_queue_pairs);
1898
1899         return 0;
1900
1901 free_unregister_netdev:
1902         vi->vdev->config->reset(vdev);
1903
1904         unregister_netdev(dev);
1905 free_vqs:
1906         cancel_delayed_work_sync(&vi->refill);
1907         free_receive_page_frags(vi);
1908         virtnet_del_vqs(vi);
1909 free_stats:
1910         free_percpu(vi->stats);
1911 free:
1912         free_netdev(dev);
1913         return err;
1914 }
1915
1916 static void remove_vq_common(struct virtnet_info *vi)
1917 {
1918         vi->vdev->config->reset(vi->vdev);
1919
1920         /* Free unused buffers in both send and recv, if any. */
1921         free_unused_bufs(vi);
1922
1923         free_receive_bufs(vi);
1924
1925         free_receive_page_frags(vi);
1926
1927         virtnet_del_vqs(vi);
1928 }
1929
1930 static void virtnet_remove(struct virtio_device *vdev)
1931 {
1932         struct virtnet_info *vi = vdev->priv;
1933
1934         unregister_hotcpu_notifier(&vi->nb);
1935
1936         /* Make sure no work handler is accessing the device. */
1937         flush_work(&vi->config_work);
1938
1939         unregister_netdev(vi->dev);
1940
1941         remove_vq_common(vi);
1942
1943         free_percpu(vi->stats);
1944         free_netdev(vi->dev);
1945 }
1946
1947 #ifdef CONFIG_PM_SLEEP
1948 static int virtnet_freeze(struct virtio_device *vdev)
1949 {
1950         struct virtnet_info *vi = vdev->priv;
1951         int i;
1952
1953         unregister_hotcpu_notifier(&vi->nb);
1954
1955         /* Make sure no work handler is accessing the device */
1956         flush_work(&vi->config_work);
1957
1958         netif_device_detach(vi->dev);
1959         cancel_delayed_work_sync(&vi->refill);
1960
1961         if (netif_running(vi->dev)) {
1962                 for (i = 0; i < vi->max_queue_pairs; i++)
1963                         napi_disable(&vi->rq[i].napi);
1964         }
1965
1966         remove_vq_common(vi);
1967
1968         return 0;
1969 }
1970
1971 static int virtnet_restore(struct virtio_device *vdev)
1972 {
1973         struct virtnet_info *vi = vdev->priv;
1974         int err, i;
1975
1976         err = init_vqs(vi);
1977         if (err)
1978                 return err;
1979
1980         virtio_device_ready(vdev);
1981
1982         if (netif_running(vi->dev)) {
1983                 for (i = 0; i < vi->curr_queue_pairs; i++)
1984                         if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
1985                                 schedule_delayed_work(&vi->refill, 0);
1986
1987                 for (i = 0; i < vi->max_queue_pairs; i++)
1988                         virtnet_napi_enable(&vi->rq[i]);
1989         }
1990
1991         netif_device_attach(vi->dev);
1992
1993         rtnl_lock();
1994         virtnet_set_queues(vi, vi->curr_queue_pairs);
1995         rtnl_unlock();
1996
1997         err = register_hotcpu_notifier(&vi->nb);
1998         if (err)
1999                 return err;
2000
2001         return 0;
2002 }
2003 #endif
2004
2005 static struct virtio_device_id id_table[] = {
2006         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
2007         { 0 },
2008 };
2009
2010 static unsigned int features[] = {
2011         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
2012         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
2013         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
2014         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
2015         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
2016         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
2017         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
2018         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
2019         VIRTIO_NET_F_CTRL_MAC_ADDR,
2020         VIRTIO_F_ANY_LAYOUT,
2021         VIRTIO_NET_F_MTU,
2022 };
2023
2024 static struct virtio_driver virtio_net_driver = {
2025         .feature_table = features,
2026         .feature_table_size = ARRAY_SIZE(features),
2027         .driver.name =  KBUILD_MODNAME,
2028         .driver.owner = THIS_MODULE,
2029         .id_table =     id_table,
2030         .probe =        virtnet_probe,
2031         .remove =       virtnet_remove,
2032         .config_changed = virtnet_config_changed,
2033 #ifdef CONFIG_PM_SLEEP
2034         .freeze =       virtnet_freeze,
2035         .restore =      virtnet_restore,
2036 #endif
2037 };
2038
2039 module_virtio_driver(virtio_net_driver);
2040
2041 MODULE_DEVICE_TABLE(virtio, id_table);
2042 MODULE_DESCRIPTION("Virtio network driver");
2043 MODULE_LICENSE("GPL");