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, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19 //#define DEBUG
  20 #include <linux/netdevice.h>
  21 #include <linux/etherdevice.h>
  22 #include <linux/ethtool.h>
  23 #include <linux/module.h>
  24 #include <linux/virtio.h>
  25 #include <linux/virtio_net.h>
  26 #include <linux/scatterlist.h>
  27 #include <linux/if_vlan.h>
  28 #include <linux/slab.h>
  29
  30 static int napi_weight = 128;
  31 module_param(napi_weight, int, 0444);
  32
  33 static bool csum = true, gso = true;
  34 module_param(csum, bool, 0444);
  35 module_param(gso, bool, 0444);
  36
  37 /* FIXME: MTU in config. */
  38 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  39 #define GOOD_COPY_LEN   128
  40
  41 #define VIRTNET_SEND_COMMAND_SG_MAX    2
  42 #define VIRTNET_DRIVER_VERSION "1.0.0"
  43
  44 struct virtnet_stats {
  45         struct u64_stats_sync tx_syncp;
  46         struct u64_stats_sync rx_syncp;
  47         u64 tx_bytes;
  48         u64 tx_packets;
  49
  50         u64 rx_bytes;
  51         u64 rx_packets;
  52 };
  53
  54 /* Internal representation of a send virtqueue */
  55 struct send_queue {
  56         /* Virtqueue associated with this send _queue */
  57         struct virtqueue *vq;
  58
  59         /* TX: fragments + linear part + virtio header */
  60         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  61
  62         /* Name of the send queue: output.$index */
  63         char name[40];
  64 };
  65
  66 /* Internal representation of a receive virtqueue */
  67 struct receive_queue {
  68         /* Virtqueue associated with this receive_queue */
  69         struct virtqueue *vq;
  70
  71         struct napi_struct napi;
  72
  73         /* Number of input buffers, and max we've ever had. */
  74         unsigned int num, max;
  75
  76         /* Chain pages by the private ptr. */
  77         struct page *pages;
  78
  79         /* RX: fragments + linear part + virtio header */
  80         struct scatterlist sg[MAX_SKB_FRAGS + 2];
  81
  82         /* Name of this receive queue: input.$index */
  83         char name[40];
  84 };
  85
  86 struct virtnet_info {
  87         struct virtio_device *vdev;
  88         struct virtqueue *cvq;
  89         struct net_device *dev;
  90         struct send_queue *sq;
  91         struct receive_queue *rq;
  92         unsigned int status;
  93
  94         /* Max # of queue pairs supported by the device */
  95         u16 max_queue_pairs;
  96
  97         /* # of queue pairs currently used by the driver */
  98         u16 curr_queue_pairs;
  99
 100         /* I like... big packets and I cannot lie! */
 101         bool big_packets;
 102
 103         /* Host will merge rx buffers for big packets (shake it! shake it!) */
 104         bool mergeable_rx_bufs;
 105
 106         /* Has control virtqueue */
 107         bool has_cvq;
 108
 109         /* enable config space updates */
 110         bool config_enable;
 111
 112         /* Active statistics */
 113         struct virtnet_stats __percpu *stats;
 114
 115         /* Work struct for refilling if we run low on memory. */
 116         struct delayed_work refill;
 117
 118         /* Work struct for config space updates */
 119         struct work_struct config_work;
 120
 121         /* Lock for config space updates */
 122         struct mutex config_lock;
 123
 124         /* Does the affinity hint is set for virtqueues? */
 125         bool affinity_hint_set;
 126 };
 127
 128 struct skb_vnet_hdr {
 129         union {
 130                 struct virtio_net_hdr hdr;
 131                 struct virtio_net_hdr_mrg_rxbuf mhdr;
 132         };
 133 };
 134
 135 struct padded_vnet_hdr {
 136         struct virtio_net_hdr hdr;
 137         /*
 138          * virtio_net_hdr should be in a separated sg buffer because of a
 139          * QEMU bug, and data sg buffer shares same page with this header sg.
 140          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
 141          */
 142         char padding[6];
 143 };
 144
 145 /* Converting between virtqueue no. and kernel tx/rx queue no.
 146  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 147  */
 148 static int vq2txq(struct virtqueue *vq)
 149 {
 150         return (virtqueue_get_queue_index(vq) - 1) / 2;
 151 }
 152
 153 static int txq2vq(int txq)
 154 {
 155         return txq * 2 + 1;
 156 }
 157
 158 static int vq2rxq(struct virtqueue *vq)
 159 {
 160         return virtqueue_get_queue_index(vq) / 2;
 161 }
 162
 163 static int rxq2vq(int rxq)
 164 {
 165         return rxq * 2;
 166 }
 167
 168 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
 169 {
 170         return (struct skb_vnet_hdr *)skb->cb;
 171 }
 172
 173 /*
 174  * private is used to chain pages for big packets, put the whole
 175  * most recent used list in the beginning for reuse
 176  */
 177 static void give_pages(struct receive_queue *rq, struct page *page)
 178 {
 179         struct page *end;
 180
 181         /* Find end of list, sew whole thing into vi->rq.pages. */
 182         for (end = page; end->private; end = (struct page *)end->private);
 183         end->private = (unsigned long)rq->pages;
 184         rq->pages = page;
 185 }
 186
 187 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 188 {
 189         struct page *p = rq->pages;
 190
 191         if (p) {
 192                 rq->pages = (struct page *)p->private;
 193                 /* clear private here, it is used to chain pages */
 194                 p->private = 0;
 195         } else
 196                 p = alloc_page(gfp_mask);
 197         return p;
 198 }
 199
 200 static void skb_xmit_done(struct virtqueue *vq)
 201 {
 202         struct virtnet_info *vi = vq->vdev->priv;
 203
 204         /* Suppress further interrupts. */
 205         virtqueue_disable_cb(vq);
 206
 207         /* We were probably waiting for more output buffers. */
 208         netif_wake_subqueue(vi->dev, vq2txq(vq));
 209 }
 210
 211 static void set_skb_frag(struct sk_buff *skb, struct page *page,
 212                          unsigned int offset, unsigned int *len)
 213 {
 214         int size = min((unsigned)PAGE_SIZE - offset, *len);
 215         int i = skb_shinfo(skb)->nr_frags;
 216
 217         __skb_fill_page_desc(skb, i, page, offset, size);
 218
 219         skb->data_len += size;
 220         skb->len += size;
 221         skb->truesize += PAGE_SIZE;
 222         skb_shinfo(skb)->nr_frags++;
 223         *len -= size;
 224 }
 225
 226 /* Called from bottom half context */
 227 static struct sk_buff *page_to_skb(struct receive_queue *rq,
 228                                    struct page *page, unsigned int len)
 229 {
 230         struct virtnet_info *vi = rq->vq->vdev->priv;
 231         struct sk_buff *skb;
 232         struct skb_vnet_hdr *hdr;
 233         unsigned int copy, hdr_len, offset;
 234         char *p;
 235
 236         p = page_address(page);
 237
 238         /* copy small packet so we can reuse these pages for small data */
 239         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
 240         if (unlikely(!skb))
 241                 return NULL;
 242
 243         hdr = skb_vnet_hdr(skb);
 244
 245         if (vi->mergeable_rx_bufs) {
 246                 hdr_len = sizeof hdr->mhdr;
 247                 offset = hdr_len;
 248         } else {
 249                 hdr_len = sizeof hdr->hdr;
 250                 offset = sizeof(struct padded_vnet_hdr);
 251         }
 252
 253         memcpy(hdr, p, hdr_len);
 254
 255         len -= hdr_len;
 256         p += offset;
 257
 258         copy = len;
 259         if (copy > skb_tailroom(skb))
 260                 copy = skb_tailroom(skb);
 261         memcpy(skb_put(skb, copy), p, copy);
 262
 263         len -= copy;
 264         offset += copy;
 265
 266         /*
 267          * Verify that we can indeed put this data into a skb.
 268          * This is here to handle cases when the device erroneously
 269          * tries to receive more than is possible. This is usually
 270          * the case of a broken device.
 271          */
 272         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 273                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 274                 dev_kfree_skb(skb);
 275                 return NULL;
 276         }
 277
 278         while (len) {
 279                 set_skb_frag(skb, page, offset, &len);
 280                 page = (struct page *)page->private;
 281                 offset = 0;
 282         }
 283
 284         if (page)
 285                 give_pages(rq, page);
 286
 287         return skb;
 288 }
 289
 290 static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb)
 291 {
 292         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 293         struct page *page;
 294         int num_buf, i, len;
 295
 296         num_buf = hdr->mhdr.num_buffers;
 297         while (--num_buf) {
 298                 i = skb_shinfo(skb)->nr_frags;
 299                 if (i >= MAX_SKB_FRAGS) {
 300                         pr_debug("%s: packet too long\n", skb->dev->name);
 301                         skb->dev->stats.rx_length_errors++;
 302                         return -EINVAL;
 303                 }
 304                 page = virtqueue_get_buf(rq->vq, &len);
 305                 if (!page) {
 306                         pr_debug("%s: rx error: %d buffers missing\n",
 307                                  skb->dev->name, hdr->mhdr.num_buffers);
 308                         skb->dev->stats.rx_length_errors++;
 309                         return -EINVAL;
 310                 }
 311
 312                 if (len > PAGE_SIZE)
 313                         len = PAGE_SIZE;
 314
 315                 set_skb_frag(skb, page, 0, &len);
 316
 317                 --rq->num;
 318         }
 319         return 0;
 320 }
 321
 322 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
 323 {
 324         struct virtnet_info *vi = rq->vq->vdev->priv;
 325         struct net_device *dev = vi->dev;
 326         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 327         struct sk_buff *skb;
 328         struct page *page;
 329         struct skb_vnet_hdr *hdr;
 330
 331         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
 332                 pr_debug("%s: short packet %i\n", dev->name, len);
 333                 dev->stats.rx_length_errors++;
 334                 if (vi->mergeable_rx_bufs || vi->big_packets)
 335                         give_pages(rq, buf);
 336                 else
 337                         dev_kfree_skb(buf);
 338                 return;
 339         }
 340
 341         if (!vi->mergeable_rx_bufs && !vi->big_packets) {
 342                 skb = buf;
 343                 len -= sizeof(struct virtio_net_hdr);
 344                 skb_trim(skb, len);
 345         } else {
 346                 page = buf;
 347                 skb = page_to_skb(rq, page, len);
 348                 if (unlikely(!skb)) {
 349                         dev->stats.rx_dropped++;
 350                         give_pages(rq, page);
 351                         return;
 352                 }
 353                 if (vi->mergeable_rx_bufs)
 354                         if (receive_mergeable(rq, skb)) {
 355                                 dev_kfree_skb(skb);
 356                                 return;
 357                         }
 358         }
 359
 360         hdr = skb_vnet_hdr(skb);
 361
 362         u64_stats_update_begin(&stats->rx_syncp);
 363         stats->rx_bytes += skb->len;
 364         stats->rx_packets++;
 365         u64_stats_update_end(&stats->rx_syncp);
 366
 367         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 368                 pr_debug("Needs csum!\n");
 369                 if (!skb_partial_csum_set(skb,
 370                                           hdr->hdr.csum_start,
 371                                           hdr->hdr.csum_offset))
 372                         goto frame_err;
 373         } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
 374                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 375         }
 376
 377         skb->protocol = eth_type_trans(skb, dev);
 378         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 379                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 380
 381         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 382                 pr_debug("GSO!\n");
 383                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 384                 case VIRTIO_NET_HDR_GSO_TCPV4:
 385                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 386                         break;
 387                 case VIRTIO_NET_HDR_GSO_UDP:
 388                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 389                         break;
 390                 case VIRTIO_NET_HDR_GSO_TCPV6:
 391                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 392                         break;
 393                 default:
 394                         net_warn_ratelimited("%s: bad gso type %u.\n",
 395                                              dev->name, hdr->hdr.gso_type);
 396                         goto frame_err;
 397                 }
 398
 399                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 400                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 401
 402                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
 403                 if (skb_shinfo(skb)->gso_size == 0) {
 404                         net_warn_ratelimited("%s: zero gso size.\n", dev->name);
 405                         goto frame_err;
 406                 }
 407
 408                 /* Header must be checked, and gso_segs computed. */
 409                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 410                 skb_shinfo(skb)->gso_segs = 0;
 411         }
 412
 413         netif_receive_skb(skb);
 414         return;
 415
 416 frame_err:
 417         dev->stats.rx_frame_errors++;
 418         dev_kfree_skb(skb);
 419 }
 420
 421 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
 422 {
 423         struct virtnet_info *vi = rq->vq->vdev->priv;
 424         struct sk_buff *skb;
 425         struct skb_vnet_hdr *hdr;
 426         int err;
 427
 428         skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp);
 429         if (unlikely(!skb))
 430                 return -ENOMEM;
 431
 432         skb_put(skb, MAX_PACKET_LEN);
 433
 434         hdr = skb_vnet_hdr(skb);
 435         sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
 436
 437         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 438
 439         err = virtqueue_add_buf(rq->vq, rq->sg, 0, 2, skb, gfp);
 440         if (err < 0)
 441                 dev_kfree_skb(skb);
 442
 443         return err;
 444 }
 445
 446 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
 447 {
 448         struct page *first, *list = NULL;
 449         char *p;
 450         int i, err, offset;
 451
 452         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 453         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 454                 first = get_a_page(rq, gfp);
 455                 if (!first) {
 456                         if (list)
 457                                 give_pages(rq, list);
 458                         return -ENOMEM;
 459                 }
 460                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
 461
 462                 /* chain new page in list head to match sg */
 463                 first->private = (unsigned long)list;
 464                 list = first;
 465         }
 466
 467         first = get_a_page(rq, gfp);
 468         if (!first) {
 469                 give_pages(rq, list);
 470                 return -ENOMEM;
 471         }
 472         p = page_address(first);
 473
 474         /* rq->sg[0], rq->sg[1] share the same page */
 475         /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
 476         sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
 477
 478         /* rq->sg[1] for data packet, from offset */
 479         offset = sizeof(struct padded_vnet_hdr);
 480         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
 481
 482         /* chain first in list head */
 483         first->private = (unsigned long)list;
 484         err = virtqueue_add_buf(rq->vq, rq->sg, 0, MAX_SKB_FRAGS + 2,
 485                                 first, gfp);
 486         if (err < 0)
 487                 give_pages(rq, first);
 488
 489         return err;
 490 }
 491
 492 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
 493 {
 494         struct page *page;
 495         int err;
 496
 497         page = get_a_page(rq, gfp);
 498         if (!page)
 499                 return -ENOMEM;
 500
 501         sg_init_one(rq->sg, page_address(page), PAGE_SIZE);
 502
 503         err = virtqueue_add_buf(rq->vq, rq->sg, 0, 1, page, gfp);
 504         if (err < 0)
 505                 give_pages(rq, page);
 506
 507         return err;
 508 }
 509
 510 /*
 511  * Returns false if we couldn't fill entirely (OOM).
 512  *
 513  * Normally run in the receive path, but can also be run from ndo_open
 514  * before we're receiving packets, or from refill_work which is
 515  * careful to disable receiving (using napi_disable).
 516  */
 517 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
 518 {
 519         struct virtnet_info *vi = rq->vq->vdev->priv;
 520         int err;
 521         bool oom;
 522
 523         do {
 524                 if (vi->mergeable_rx_bufs)
 525                         err = add_recvbuf_mergeable(rq, gfp);
 526                 else if (vi->big_packets)
 527                         err = add_recvbuf_big(rq, gfp);
 528                 else
 529                         err = add_recvbuf_small(rq, gfp);
 530
 531                 oom = err == -ENOMEM;
 532                 if (err)
 533                         break;
 534                 ++rq->num;
 535         } while (rq->vq->num_free);
 536         if (unlikely(rq->num > rq->max))
 537                 rq->max = rq->num;
 538         virtqueue_kick(rq->vq);
 539         return !oom;
 540 }
 541
 542 static void skb_recv_done(struct virtqueue *rvq)
 543 {
 544         struct virtnet_info *vi = rvq->vdev->priv;
 545         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 546
 547         /* Schedule NAPI, Suppress further interrupts if successful. */
 548         if (napi_schedule_prep(&rq->napi)) {
 549                 virtqueue_disable_cb(rvq);
 550                 __napi_schedule(&rq->napi);
 551         }
 552 }
 553
 554 static void virtnet_napi_enable(struct receive_queue *rq)
 555 {
 556         napi_enable(&rq->napi);
 557
 558         /* If all buffers were filled by other side before we napi_enabled, we
 559          * won't get another interrupt, so process any outstanding packets
 560          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 561          * We synchronize against interrupts via NAPI_STATE_SCHED */
 562         if (napi_schedule_prep(&rq->napi)) {
 563                 virtqueue_disable_cb(rq->vq);
 564                 local_bh_disable();
 565                 __napi_schedule(&rq->napi);
 566                 local_bh_enable();
 567         }
 568 }
 569
 570 static void refill_work(struct work_struct *work)
 571 {
 572         struct virtnet_info *vi =
 573                 container_of(work, struct virtnet_info, refill.work);
 574         bool still_empty;
 575         int i;
 576
 577         for (i = 0; i < vi->max_queue_pairs; i++) {
 578                 struct receive_queue *rq = &vi->rq[i];
 579
 580                 napi_disable(&rq->napi);
 581                 still_empty = !try_fill_recv(rq, GFP_KERNEL);
 582                 virtnet_napi_enable(rq);
 583
 584                 /* In theory, this can happen: if we don't get any buffers in
 585                  * we will *never* try to fill again.
 586                  */
 587                 if (still_empty)
 588                         schedule_delayed_work(&vi->refill, HZ/2);
 589         }
 590 }
 591
 592 static int virtnet_poll(struct napi_struct *napi, int budget)
 593 {
 594         struct receive_queue *rq =
 595                 container_of(napi, struct receive_queue, napi);
 596         struct virtnet_info *vi = rq->vq->vdev->priv;
 597         void *buf;
 598         unsigned int len, received = 0;
 599
 600 again:
 601         while (received < budget &&
 602                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
 603                 receive_buf(rq, buf, len);
 604                 --rq->num;
 605                 received++;
 606         }
 607
 608         if (rq->num < rq->max / 2) {
 609                 if (!try_fill_recv(rq, GFP_ATOMIC))
 610                         schedule_delayed_work(&vi->refill, 0);
 611         }
 612
 613         /* Out of packets? */
 614         if (received < budget) {
 615                 napi_complete(napi);
 616                 if (unlikely(!virtqueue_enable_cb(rq->vq)) &&
 617                     napi_schedule_prep(napi)) {
 618                         virtqueue_disable_cb(rq->vq);
 619                         __napi_schedule(napi);
 620                         goto again;
 621                 }
 622         }
 623
 624         return received;
 625 }
 626
 627 static int virtnet_open(struct net_device *dev)
 628 {
 629         struct virtnet_info *vi = netdev_priv(dev);
 630         int i;
 631
 632         for (i = 0; i < vi->max_queue_pairs; i++) {
 633                 /* Make sure we have some buffers: if oom use wq. */
 634                 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
 635                         schedule_delayed_work(&vi->refill, 0);
 636                 virtnet_napi_enable(&vi->rq[i]);
 637         }
 638
 639         return 0;
 640 }
 641
 642 static void free_old_xmit_skbs(struct send_queue *sq)
 643 {
 644         struct sk_buff *skb;
 645         unsigned int len;
 646         struct virtnet_info *vi = sq->vq->vdev->priv;
 647         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 648
 649         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 650                 pr_debug("Sent skb %p\n", skb);
 651
 652                 u64_stats_update_begin(&stats->tx_syncp);
 653                 stats->tx_bytes += skb->len;
 654                 stats->tx_packets++;
 655                 u64_stats_update_end(&stats->tx_syncp);
 656
 657                 dev_kfree_skb_any(skb);
 658         }
 659 }
 660
 661 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 662 {
 663         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 664         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 665         struct virtnet_info *vi = sq->vq->vdev->priv;
 666         unsigned num_sg;
 667
 668         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 669
 670         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 671                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 672                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
 673                 hdr->hdr.csum_offset = skb->csum_offset;
 674         } else {
 675                 hdr->hdr.flags = 0;
 676                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 677         }
 678
 679         if (skb_is_gso(skb)) {
 680                 hdr->hdr.hdr_len = skb_headlen(skb);
 681                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
 682                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 683                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 684                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 685                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 686                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 687                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 688                 else
 689                         BUG();
 690                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 691                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 692         } else {
 693                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 694                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
 695         }
 696
 697         hdr->mhdr.num_buffers = 0;
 698
 699         /* Encode metadata header at front. */
 700         if (vi->mergeable_rx_bufs)
 701                 sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr);
 702         else
 703                 sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);
 704
 705         num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
 706         return virtqueue_add_buf(sq->vq, sq->sg, num_sg,
 707                                  0, skb, GFP_ATOMIC);
 708 }
 709
 710 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 711 {
 712         struct virtnet_info *vi = netdev_priv(dev);
 713         int qnum = skb_get_queue_mapping(skb);
 714         struct send_queue *sq = &vi->sq[qnum];
 715         int err;
 716
 717         /* Free up any pending old buffers before queueing new ones. */
 718         free_old_xmit_skbs(sq);
 719
 720         /* Try to transmit */
 721         err = xmit_skb(sq, skb);
 722
 723         /* This should not happen! */
 724         if (unlikely(err)) {
 725                 dev->stats.tx_fifo_errors++;
 726                 if (net_ratelimit())
 727                         dev_warn(&dev->dev,
 728                                  "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
 729                 dev->stats.tx_dropped++;
 730                 kfree_skb(skb);
 731                 return NETDEV_TX_OK;
 732         }
 733         virtqueue_kick(sq->vq);
 734
 735         /* Don't wait up for transmitted skbs to be freed. */
 736         skb_orphan(skb);
 737         nf_reset(skb);
 738
 739         /* Apparently nice girls don't return TX_BUSY; stop the queue
 740          * before it gets out of hand.  Naturally, this wastes entries. */
 741         if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
 742                 netif_stop_subqueue(dev, qnum);
 743                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 744                         /* More just got used, free them then recheck. */
 745                         free_old_xmit_skbs(sq);
 746                         if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
 747                                 netif_start_subqueue(dev, qnum);
 748                                 virtqueue_disable_cb(sq->vq);
 749                         }
 750                 }
 751         }
 752
 753         return NETDEV_TX_OK;
 754 }
 755
 756 static int virtnet_set_mac_address(struct net_device *dev, void *p)
 757 {
 758         struct virtnet_info *vi = netdev_priv(dev);
 759         struct virtio_device *vdev = vi->vdev;
 760         int ret;
 761
 762         ret = eth_mac_addr(dev, p);
 763         if (ret)
 764                 return ret;
 765
 766         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
 767                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
 768                                   dev->dev_addr, dev->addr_len);
 769
 770         return 0;
 771 }
 772
 773 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
 774                                                struct rtnl_link_stats64 *tot)
 775 {
 776         struct virtnet_info *vi = netdev_priv(dev);
 777         int cpu;
 778         unsigned int start;
 779
 780         for_each_possible_cpu(cpu) {
 781                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
 782                 u64 tpackets, tbytes, rpackets, rbytes;
 783
 784                 do {
 785                         start = u64_stats_fetch_begin_bh(&stats->tx_syncp);
 786                         tpackets = stats->tx_packets;
 787                         tbytes   = stats->tx_bytes;
 788                 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start));
 789
 790                 do {
 791                         start = u64_stats_fetch_begin_bh(&stats->rx_syncp);
 792                         rpackets = stats->rx_packets;
 793                         rbytes   = stats->rx_bytes;
 794                 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start));
 795
 796                 tot->rx_packets += rpackets;
 797                 tot->tx_packets += tpackets;
 798                 tot->rx_bytes   += rbytes;
 799                 tot->tx_bytes   += tbytes;
 800         }
 801
 802         tot->tx_dropped = dev->stats.tx_dropped;
 803         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
 804         tot->rx_dropped = dev->stats.rx_dropped;
 805         tot->rx_length_errors = dev->stats.rx_length_errors;
 806         tot->rx_frame_errors = dev->stats.rx_frame_errors;
 807
 808         return tot;
 809 }
 810
 811 #ifdef CONFIG_NET_POLL_CONTROLLER
 812 static void virtnet_netpoll(struct net_device *dev)
 813 {
 814         struct virtnet_info *vi = netdev_priv(dev);
 815         int i;
 816
 817         for (i = 0; i < vi->curr_queue_pairs; i++)
 818                 napi_schedule(&vi->rq[i].napi);
 819 }
 820 #endif
 821
 822 /*
 823  * Send command via the control virtqueue and check status.  Commands
 824  * supported by the hypervisor, as indicated by feature bits, should
 825  * never fail unless improperly formated.
 826  */
 827 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 828                                  struct scatterlist *data, int out, int in)
 829 {
 830         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
 831         struct virtio_net_ctrl_hdr ctrl;
 832         virtio_net_ctrl_ack status = ~0;
 833         unsigned int tmp;
 834         int i;
 835
 836         /* Caller should know better */
 837         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
 838                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
 839
 840         out++; /* Add header */
 841         in++; /* Add return status */
 842
 843         ctrl.class = class;
 844         ctrl.cmd = cmd;
 845
 846         sg_init_table(sg, out + in);
 847
 848         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
 849         for_each_sg(data, s, out + in - 2, i)
 850                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
 851         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
 852
 853         BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0);
 854
 855         virtqueue_kick(vi->cvq);
 856
 857         /*
 858          * Spin for a response, the kick causes an ioport write, trapping
 859          * into the hypervisor, so the request should be handled immediately.
 860          */
 861         while (!virtqueue_get_buf(vi->cvq, &tmp))
 862                 cpu_relax();
 863
 864         return status == VIRTIO_NET_OK;
 865 }
 866
 867 static void virtnet_ack_link_announce(struct virtnet_info *vi)
 868 {
 869         rtnl_lock();
 870         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
 871                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL,
 872                                   0, 0))
 873                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
 874         rtnl_unlock();
 875 }
 876
 877 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
 878 {
 879         struct scatterlist sg;
 880         struct virtio_net_ctrl_mq s;
 881         struct net_device *dev = vi->dev;
 882
 883         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
 884                 return 0;
 885
 886         s.virtqueue_pairs = queue_pairs;
 887         sg_init_one(&sg, &s, sizeof(s));
 888
 889         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
 890                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, 1, 0)){
 891                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
 892                          queue_pairs);
 893                 return -EINVAL;
 894         } else
 895                 vi->curr_queue_pairs = queue_pairs;
 896
 897         return 0;
 898 }
 899
 900 static int virtnet_close(struct net_device *dev)
 901 {
 902         struct virtnet_info *vi = netdev_priv(dev);
 903         int i;
 904
 905         /* Make sure refill_work doesn't re-enable napi! */
 906         cancel_delayed_work_sync(&vi->refill);
 907
 908         for (i = 0; i < vi->max_queue_pairs; i++)
 909                 napi_disable(&vi->rq[i].napi);
 910
 911         return 0;
 912 }
 913
 914 static void virtnet_set_rx_mode(struct net_device *dev)
 915 {
 916         struct virtnet_info *vi = netdev_priv(dev);
 917         struct scatterlist sg[2];
 918         u8 promisc, allmulti;
 919         struct virtio_net_ctrl_mac *mac_data;
 920         struct netdev_hw_addr *ha;
 921         int uc_count;
 922         int mc_count;
 923         void *buf;
 924         int i;
 925
 926         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
 927         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
 928                 return;
 929
 930         promisc = ((dev->flags & IFF_PROMISC) != 0);
 931         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
 932
 933         sg_init_one(sg, &promisc, sizeof(promisc));
 934
 935         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 936                                   VIRTIO_NET_CTRL_RX_PROMISC,
 937                                   sg, 1, 0))
 938                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
 939                          promisc ? "en" : "dis");
 940
 941         sg_init_one(sg, &allmulti, sizeof(allmulti));
 942
 943         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 944                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
 945                                   sg, 1, 0))
 946                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
 947                          allmulti ? "en" : "dis");
 948
 949         uc_count = netdev_uc_count(dev);
 950         mc_count = netdev_mc_count(dev);
 951         /* MAC filter - use one buffer for both lists */
 952         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
 953                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
 954         mac_data = buf;
 955         if (!buf) {
 956                 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
 957                 return;
 958         }
 959
 960         sg_init_table(sg, 2);
 961
 962         /* Store the unicast list and count in the front of the buffer */
 963         mac_data->entries = uc_count;
 964         i = 0;
 965         netdev_for_each_uc_addr(ha, dev)
 966                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 967
 968         sg_set_buf(&sg[0], mac_data,
 969                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
 970
 971         /* multicast list and count fill the end */
 972         mac_data = (void *)&mac_data->macs[uc_count][0];
 973
 974         mac_data->entries = mc_count;
 975         i = 0;
 976         netdev_for_each_mc_addr(ha, dev)
 977                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 978
 979         sg_set_buf(&sg[1], mac_data,
 980                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
 981
 982         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
 983                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
 984                                   sg, 2, 0))
 985                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
 986
 987         kfree(buf);
 988 }
 989
 990 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
 991 {
 992         struct virtnet_info *vi = netdev_priv(dev);
 993         struct scatterlist sg;
 994
 995         sg_init_one(&sg, &vid, sizeof(vid));
 996
 997         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
 998                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
 999                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1000         return 0;
1001 }
1002
1003 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
1004 {
1005         struct virtnet_info *vi = netdev_priv(dev);
1006         struct scatterlist sg;
1007
1008         sg_init_one(&sg, &vid, sizeof(vid));
1009
1010         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1011                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
1012                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1013         return 0;
1014 }
1015
1016 static void virtnet_set_affinity(struct virtnet_info *vi, bool set)
1017 {
1018         int i;
1019
1020         /* In multiqueue mode, when the number of cpu is equal to the number of
1021          * queue pairs, we let the queue pairs to be private to one cpu by
1022          * setting the affinity hint to eliminate the contention.
1023          */
1024         if ((vi->curr_queue_pairs == 1 ||
1025              vi->max_queue_pairs != num_online_cpus()) && set) {
1026                 if (vi->affinity_hint_set)
1027                         set = false;
1028                 else
1029                         return;
1030         }
1031
1032         for (i = 0; i < vi->max_queue_pairs; i++) {
1033                 int cpu = set ? i : -1;
1034                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1035                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1036         }
1037
1038         if (set)
1039                 vi->affinity_hint_set = true;
1040         else
1041                 vi->affinity_hint_set = false;
1042 }
1043
1044 static void virtnet_get_ringparam(struct net_device *dev,
1045                                 struct ethtool_ringparam *ring)
1046 {
1047         struct virtnet_info *vi = netdev_priv(dev);
1048
1049         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1050         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1051         ring->rx_pending = ring->rx_max_pending;
1052         ring->tx_pending = ring->tx_max_pending;
1053 }
1054
1055
1056 static void virtnet_get_drvinfo(struct net_device *dev,
1057                                 struct ethtool_drvinfo *info)
1058 {
1059         struct virtnet_info *vi = netdev_priv(dev);
1060         struct virtio_device *vdev = vi->vdev;
1061
1062         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1063         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1064         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1065
1066 }
1067
1068 /* TODO: Eliminate OOO packets during switching */
1069 static int virtnet_set_channels(struct net_device *dev,
1070                                 struct ethtool_channels *channels)
1071 {
1072         struct virtnet_info *vi = netdev_priv(dev);
1073         u16 queue_pairs = channels->combined_count;
1074         int err;
1075
1076         /* We don't support separate rx/tx channels.
1077          * We don't allow setting 'other' channels.
1078          */
1079         if (channels->rx_count || channels->tx_count || channels->other_count)
1080                 return -EINVAL;
1081
1082         if (queue_pairs > vi->max_queue_pairs)
1083                 return -EINVAL;
1084
1085         err = virtnet_set_queues(vi, queue_pairs);
1086         if (!err) {
1087                 netif_set_real_num_tx_queues(dev, queue_pairs);
1088                 netif_set_real_num_rx_queues(dev, queue_pairs);
1089
1090                 virtnet_set_affinity(vi, true);
1091         }
1092
1093         return err;
1094 }
1095
1096 static void virtnet_get_channels(struct net_device *dev,
1097                                  struct ethtool_channels *channels)
1098 {
1099         struct virtnet_info *vi = netdev_priv(dev);
1100
1101         channels->combined_count = vi->curr_queue_pairs;
1102         channels->max_combined = vi->max_queue_pairs;
1103         channels->max_other = 0;
1104         channels->rx_count = 0;
1105         channels->tx_count = 0;
1106         channels->other_count = 0;
1107 }
1108
1109 static const struct ethtool_ops virtnet_ethtool_ops = {
1110         .get_drvinfo = virtnet_get_drvinfo,
1111         .get_link = ethtool_op_get_link,
1112         .get_ringparam = virtnet_get_ringparam,
1113         .set_channels = virtnet_set_channels,
1114         .get_channels = virtnet_get_channels,
1115 };
1116
1117 #define MIN_MTU 68
1118 #define MAX_MTU 65535
1119
1120 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1121 {
1122         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1123                 return -EINVAL;
1124         dev->mtu = new_mtu;
1125         return 0;
1126 }
1127
1128 /* To avoid contending a lock hold by a vcpu who would exit to host, select the
1129  * txq based on the processor id.
1130  * TODO: handle cpu hotplug.
1131  */
1132 static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb)
1133 {
1134         int txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) :
1135                   smp_processor_id();
1136
1137         while (unlikely(txq >= dev->real_num_tx_queues))
1138                 txq -= dev->real_num_tx_queues;
1139
1140         return txq;
1141 }
1142
1143 static const struct net_device_ops virtnet_netdev = {
1144         .ndo_open            = virtnet_open,
1145         .ndo_stop            = virtnet_close,
1146         .ndo_start_xmit      = start_xmit,
1147         .ndo_validate_addr   = eth_validate_addr,
1148         .ndo_set_mac_address = virtnet_set_mac_address,
1149         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1150         .ndo_change_mtu      = virtnet_change_mtu,
1151         .ndo_get_stats64     = virtnet_stats,
1152         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1153         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1154         .ndo_select_queue     = virtnet_select_queue,
1155 #ifdef CONFIG_NET_POLL_CONTROLLER
1156         .ndo_poll_controller = virtnet_netpoll,
1157 #endif
1158 };
1159
1160 static void virtnet_config_changed_work(struct work_struct *work)
1161 {
1162         struct virtnet_info *vi =
1163                 container_of(work, struct virtnet_info, config_work);
1164         u16 v;
1165
1166         mutex_lock(&vi->config_lock);
1167         if (!vi->config_enable)
1168                 goto done;
1169
1170         if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
1171                               offsetof(struct virtio_net_config, status),
1172                               &v) < 0)
1173                 goto done;
1174
1175         if (v & VIRTIO_NET_S_ANNOUNCE) {
1176                 netdev_notify_peers(vi->dev);
1177                 virtnet_ack_link_announce(vi);
1178         }
1179
1180         /* Ignore unknown (future) status bits */
1181         v &= VIRTIO_NET_S_LINK_UP;
1182
1183         if (vi->status == v)
1184                 goto done;
1185
1186         vi->status = v;
1187
1188         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1189                 netif_carrier_on(vi->dev);
1190                 netif_tx_wake_all_queues(vi->dev);
1191         } else {
1192                 netif_carrier_off(vi->dev);
1193                 netif_tx_stop_all_queues(vi->dev);
1194         }
1195 done:
1196         mutex_unlock(&vi->config_lock);
1197 }
1198
1199 static void virtnet_config_changed(struct virtio_device *vdev)
1200 {
1201         struct virtnet_info *vi = vdev->priv;
1202
1203         schedule_work(&vi->config_work);
1204 }
1205
1206 static void virtnet_free_queues(struct virtnet_info *vi)
1207 {
1208         kfree(vi->rq);
1209         kfree(vi->sq);
1210 }
1211
1212 static void free_receive_bufs(struct virtnet_info *vi)
1213 {
1214         int i;
1215
1216         for (i = 0; i < vi->max_queue_pairs; i++) {
1217                 while (vi->rq[i].pages)
1218                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1219         }
1220 }
1221
1222 static void free_unused_bufs(struct virtnet_info *vi)
1223 {
1224         void *buf;
1225         int i;
1226
1227         for (i = 0; i < vi->max_queue_pairs; i++) {
1228                 struct virtqueue *vq = vi->sq[i].vq;
1229                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1230                         dev_kfree_skb(buf);
1231         }
1232
1233         for (i = 0; i < vi->max_queue_pairs; i++) {
1234                 struct virtqueue *vq = vi->rq[i].vq;
1235
1236                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1237                         if (vi->mergeable_rx_bufs || vi->big_packets)
1238                                 give_pages(&vi->rq[i], buf);
1239                         else
1240                                 dev_kfree_skb(buf);
1241                         --vi->rq[i].num;
1242                 }
1243                 BUG_ON(vi->rq[i].num != 0);
1244         }
1245 }
1246
1247 static void virtnet_del_vqs(struct virtnet_info *vi)
1248 {
1249         struct virtio_device *vdev = vi->vdev;
1250
1251         virtnet_set_affinity(vi, false);
1252
1253         vdev->config->del_vqs(vdev);
1254
1255         virtnet_free_queues(vi);
1256 }
1257
1258 static int virtnet_find_vqs(struct virtnet_info *vi)
1259 {
1260         vq_callback_t **callbacks;
1261         struct virtqueue **vqs;
1262         int ret = -ENOMEM;
1263         int i, total_vqs;
1264         const char **names;
1265
1266         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1267          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1268          * possible control vq.
1269          */
1270         total_vqs = vi->max_queue_pairs * 2 +
1271                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1272
1273         /* Allocate space for find_vqs parameters */
1274         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1275         if (!vqs)
1276                 goto err_vq;
1277         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1278         if (!callbacks)
1279                 goto err_callback;
1280         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1281         if (!names)
1282                 goto err_names;
1283
1284         /* Parameters for control virtqueue, if any */
1285         if (vi->has_cvq) {
1286                 callbacks[total_vqs - 1] = NULL;
1287                 names[total_vqs - 1] = "control";
1288         }
1289
1290         /* Allocate/initialize parameters for send/receive virtqueues */
1291         for (i = 0; i < vi->max_queue_pairs; i++) {
1292                 callbacks[rxq2vq(i)] = skb_recv_done;
1293                 callbacks[txq2vq(i)] = skb_xmit_done;
1294                 sprintf(vi->rq[i].name, "input.%d", i);
1295                 sprintf(vi->sq[i].name, "output.%d", i);
1296                 names[rxq2vq(i)] = vi->rq[i].name;
1297                 names[txq2vq(i)] = vi->sq[i].name;
1298         }
1299
1300         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1301                                          names);
1302         if (ret)
1303                 goto err_find;
1304
1305         if (vi->has_cvq) {
1306                 vi->cvq = vqs[total_vqs - 1];
1307                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1308                         vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
1309         }
1310
1311         for (i = 0; i < vi->max_queue_pairs; i++) {
1312                 vi->rq[i].vq = vqs[rxq2vq(i)];
1313                 vi->sq[i].vq = vqs[txq2vq(i)];
1314         }
1315
1316         kfree(names);
1317         kfree(callbacks);
1318         kfree(vqs);
1319
1320         return 0;
1321
1322 err_find:
1323         kfree(names);
1324 err_names:
1325         kfree(callbacks);
1326 err_callback:
1327         kfree(vqs);
1328 err_vq:
1329         return ret;
1330 }
1331
1332 static int virtnet_alloc_queues(struct virtnet_info *vi)
1333 {
1334         int i;
1335
1336         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1337         if (!vi->sq)
1338                 goto err_sq;
1339         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1340         if (!vi->rq)
1341                 goto err_rq;
1342
1343         INIT_DELAYED_WORK(&vi->refill, refill_work);
1344         for (i = 0; i < vi->max_queue_pairs; i++) {
1345                 vi->rq[i].pages = NULL;
1346                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1347                                napi_weight);
1348
1349                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1350                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1351         }
1352
1353         return 0;
1354
1355 err_rq:
1356         kfree(vi->sq);
1357 err_sq:
1358         return -ENOMEM;
1359 }
1360
1361 static int init_vqs(struct virtnet_info *vi)
1362 {
1363         int ret;
1364
1365         /* Allocate send & receive queues */
1366         ret = virtnet_alloc_queues(vi);
1367         if (ret)
1368                 goto err;
1369
1370         ret = virtnet_find_vqs(vi);
1371         if (ret)
1372                 goto err_free;
1373
1374         virtnet_set_affinity(vi, true);
1375         return 0;
1376
1377 err_free:
1378         virtnet_free_queues(vi);
1379 err:
1380         return ret;
1381 }
1382
1383 static int virtnet_probe(struct virtio_device *vdev)
1384 {
1385         int i, err;
1386         struct net_device *dev;
1387         struct virtnet_info *vi;
1388         u16 max_queue_pairs;
1389
1390         /* Find if host supports multiqueue virtio_net device */
1391         err = virtio_config_val(vdev, VIRTIO_NET_F_MQ,
1392                                 offsetof(struct virtio_net_config,
1393                                 max_virtqueue_pairs), &max_queue_pairs);
1394
1395         /* We need at least 2 queue's */
1396         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1397             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1398             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1399                 max_queue_pairs = 1;
1400
1401         /* Allocate ourselves a network device with room for our info */
1402         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1403         if (!dev)
1404                 return -ENOMEM;
1405
1406         /* Set up network device as normal. */
1407         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1408         dev->netdev_ops = &virtnet_netdev;
1409         dev->features = NETIF_F_HIGHDMA;
1410
1411         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1412         SET_NETDEV_DEV(dev, &vdev->dev);
1413
1414         /* Do we support "hardware" checksums? */
1415         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1416                 /* This opens up the world of extra features. */
1417                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1418                 if (csum)
1419                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1420
1421                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1422                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1423                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1424                 }
1425                 /* Individual feature bits: what can host handle? */
1426                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1427                         dev->hw_features |= NETIF_F_TSO;
1428                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1429                         dev->hw_features |= NETIF_F_TSO6;
1430                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1431                         dev->hw_features |= NETIF_F_TSO_ECN;
1432                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1433                         dev->hw_features |= NETIF_F_UFO;
1434
1435                 if (gso)
1436                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1437                 /* (!csum && gso) case will be fixed by register_netdev() */
1438         }
1439
1440         /* Configuration may specify what MAC to use.  Otherwise random. */
1441         if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
1442                                   offsetof(struct virtio_net_config, mac),
1443                                   dev->dev_addr, dev->addr_len) < 0)
1444                 eth_hw_addr_random(dev);
1445
1446         /* Set up our device-specific information */
1447         vi = netdev_priv(dev);
1448         vi->dev = dev;
1449         vi->vdev = vdev;
1450         vdev->priv = vi;
1451         vi->stats = alloc_percpu(struct virtnet_stats);
1452         err = -ENOMEM;
1453         if (vi->stats == NULL)
1454                 goto free;
1455
1456         mutex_init(&vi->config_lock);
1457         vi->config_enable = true;
1458         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1459
1460         /* If we can receive ANY GSO packets, we must allocate large ones. */
1461         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1462             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1463             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1464                 vi->big_packets = true;
1465
1466         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1467                 vi->mergeable_rx_bufs = true;
1468
1469         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1470                 vi->has_cvq = true;
1471
1472         /* Use single tx/rx queue pair as default */
1473         vi->curr_queue_pairs = 1;
1474         vi->max_queue_pairs = max_queue_pairs;
1475
1476         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1477         err = init_vqs(vi);
1478         if (err)
1479                 goto free_stats;
1480
1481         netif_set_real_num_tx_queues(dev, 1);
1482         netif_set_real_num_rx_queues(dev, 1);
1483
1484         err = register_netdev(dev);
1485         if (err) {
1486                 pr_debug("virtio_net: registering device failed\n");
1487                 goto free_vqs;
1488         }
1489
1490         /* Last of all, set up some receive buffers. */
1491         for (i = 0; i < vi->max_queue_pairs; i++) {
1492                 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1493
1494                 /* If we didn't even get one input buffer, we're useless. */
1495                 if (vi->rq[i].num == 0) {
1496                         free_unused_bufs(vi);
1497                         err = -ENOMEM;
1498                         goto free_recv_bufs;
1499                 }
1500         }
1501
1502         /* Assume link up if device can't report link status,
1503            otherwise get link status from config. */
1504         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1505                 netif_carrier_off(dev);
1506                 schedule_work(&vi->config_work);
1507         } else {
1508                 vi->status = VIRTIO_NET_S_LINK_UP;
1509                 netif_carrier_on(dev);
1510         }
1511
1512         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1513                  dev->name, max_queue_pairs);
1514
1515         return 0;
1516
1517 free_recv_bufs:
1518         free_receive_bufs(vi);
1519         unregister_netdev(dev);
1520 free_vqs:
1521         cancel_delayed_work_sync(&vi->refill);
1522         virtnet_del_vqs(vi);
1523 free_stats:
1524         free_percpu(vi->stats);
1525 free:
1526         free_netdev(dev);
1527         return err;
1528 }
1529
1530 static void remove_vq_common(struct virtnet_info *vi)
1531 {
1532         vi->vdev->config->reset(vi->vdev);
1533
1534         /* Free unused buffers in both send and recv, if any. */
1535         free_unused_bufs(vi);
1536
1537         free_receive_bufs(vi);
1538
1539         virtnet_del_vqs(vi);
1540 }
1541
1542 static void virtnet_remove(struct virtio_device *vdev)
1543 {
1544         struct virtnet_info *vi = vdev->priv;
1545
1546         /* Prevent config work handler from accessing the device. */
1547         mutex_lock(&vi->config_lock);
1548         vi->config_enable = false;
1549         mutex_unlock(&vi->config_lock);
1550
1551         unregister_netdev(vi->dev);
1552
1553         remove_vq_common(vi);
1554
1555         flush_work(&vi->config_work);
1556
1557         free_percpu(vi->stats);
1558         free_netdev(vi->dev);
1559 }
1560
1561 #ifdef CONFIG_PM
1562 static int virtnet_freeze(struct virtio_device *vdev)
1563 {
1564         struct virtnet_info *vi = vdev->priv;
1565         int i;
1566
1567         /* Prevent config work handler from accessing the device */
1568         mutex_lock(&vi->config_lock);
1569         vi->config_enable = false;
1570         mutex_unlock(&vi->config_lock);
1571
1572         netif_device_detach(vi->dev);
1573         cancel_delayed_work_sync(&vi->refill);
1574
1575         if (netif_running(vi->dev))
1576                 for (i = 0; i < vi->max_queue_pairs; i++) {
1577                         napi_disable(&vi->rq[i].napi);
1578                         netif_napi_del(&vi->rq[i].napi);
1579                 }
1580
1581         remove_vq_common(vi);
1582
1583         flush_work(&vi->config_work);
1584
1585         return 0;
1586 }
1587
1588 static int virtnet_restore(struct virtio_device *vdev)
1589 {
1590         struct virtnet_info *vi = vdev->priv;
1591         int err, i;
1592
1593         err = init_vqs(vi);
1594         if (err)
1595                 return err;
1596
1597         if (netif_running(vi->dev))
1598                 for (i = 0; i < vi->max_queue_pairs; i++)
1599                         virtnet_napi_enable(&vi->rq[i]);
1600
1601         netif_device_attach(vi->dev);
1602
1603         for (i = 0; i < vi->max_queue_pairs; i++)
1604                 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1605                         schedule_delayed_work(&vi->refill, 0);
1606
1607         mutex_lock(&vi->config_lock);
1608         vi->config_enable = true;
1609         mutex_unlock(&vi->config_lock);
1610
1611         virtnet_set_queues(vi, vi->curr_queue_pairs);
1612
1613         return 0;
1614 }
1615 #endif
1616
1617 static struct virtio_device_id id_table[] = {
1618         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1619         { 0 },
1620 };
1621
1622 static unsigned int features[] = {
1623         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1624         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1625         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1626         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1627         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1628         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1629         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1630         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1631 };
1632
1633 static struct virtio_driver virtio_net_driver = {
1634         .feature_table = features,
1635         .feature_table_size = ARRAY_SIZE(features),
1636         .driver.name =  KBUILD_MODNAME,
1637         .driver.owner = THIS_MODULE,
1638         .id_table =     id_table,
1639         .probe =        virtnet_probe,
1640         .remove =       virtnet_remove,
1641         .config_changed = virtnet_config_changed,
1642 #ifdef CONFIG_PM
1643         .freeze =       virtnet_freeze,
1644         .restore =      virtnet_restore,
1645 #endif
1646 };
1647
1648 static int __init init(void)
1649 {
1650         return register_virtio_driver(&virtio_net_driver);
1651 }
1652
1653 static void __exit fini(void)
1654 {
1655         unregister_virtio_driver(&virtio_net_driver);
1656 }
1657 module_init(init);
1658 module_exit(fini);
1659
1660 MODULE_DEVICE_TABLE(virtio, id_table);
1661 MODULE_DESCRIPTION("Virtio network driver");
1662 MODULE_LICENSE("GPL");