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         unsigned int num_sg;
 134 };
 135
 136 struct padded_vnet_hdr {
 137         struct virtio_net_hdr hdr;
 138         /*
 139          * virtio_net_hdr should be in a separated sg buffer because of a
 140          * QEMU bug, and data sg buffer shares same page with this header sg.
 141          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
 142          */
 143         char padding[6];
 144 };
 145
 146 /* Converting between virtqueue no. and kernel tx/rx queue no.
 147  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
 148  */
 149 static int vq2txq(struct virtqueue *vq)
 150 {
 151         return (virtqueue_get_queue_index(vq) - 1) / 2;
 152 }
 153
 154 static int txq2vq(int txq)
 155 {
 156         return txq * 2 + 1;
 157 }
 158
 159 static int vq2rxq(struct virtqueue *vq)
 160 {
 161         return virtqueue_get_queue_index(vq) / 2;
 162 }
 163
 164 static int rxq2vq(int rxq)
 165 {
 166         return rxq * 2;
 167 }
 168
 169 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
 170 {
 171         return (struct skb_vnet_hdr *)skb->cb;
 172 }
 173
 174 /*
 175  * private is used to chain pages for big packets, put the whole
 176  * most recent used list in the beginning for reuse
 177  */
 178 static void give_pages(struct receive_queue *rq, struct page *page)
 179 {
 180         struct page *end;
 181
 182         /* Find end of list, sew whole thing into vi->rq.pages. */
 183         for (end = page; end->private; end = (struct page *)end->private);
 184         end->private = (unsigned long)rq->pages;
 185         rq->pages = page;
 186 }
 187
 188 static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask)
 189 {
 190         struct page *p = rq->pages;
 191
 192         if (p) {
 193                 rq->pages = (struct page *)p->private;
 194                 /* clear private here, it is used to chain pages */
 195                 p->private = 0;
 196         } else
 197                 p = alloc_page(gfp_mask);
 198         return p;
 199 }
 200
 201 static void skb_xmit_done(struct virtqueue *vq)
 202 {
 203         struct virtnet_info *vi = vq->vdev->priv;
 204
 205         /* Suppress further interrupts. */
 206         virtqueue_disable_cb(vq);
 207
 208         /* We were probably waiting for more output buffers. */
 209         netif_wake_subqueue(vi->dev, vq2txq(vq));
 210 }
 211
 212 static void set_skb_frag(struct sk_buff *skb, struct page *page,
 213                          unsigned int offset, unsigned int *len)
 214 {
 215         int size = min((unsigned)PAGE_SIZE - offset, *len);
 216         int i = skb_shinfo(skb)->nr_frags;
 217
 218         __skb_fill_page_desc(skb, i, page, offset, size);
 219
 220         skb->data_len += size;
 221         skb->len += size;
 222         skb->truesize += PAGE_SIZE;
 223         skb_shinfo(skb)->nr_frags++;
 224         *len -= size;
 225 }
 226
 227 /* Called from bottom half context */
 228 static struct sk_buff *page_to_skb(struct receive_queue *rq,
 229                                    struct page *page, unsigned int len)
 230 {
 231         struct virtnet_info *vi = rq->vq->vdev->priv;
 232         struct sk_buff *skb;
 233         struct skb_vnet_hdr *hdr;
 234         unsigned int copy, hdr_len, offset;
 235         char *p;
 236
 237         p = page_address(page);
 238
 239         /* copy small packet so we can reuse these pages for small data */
 240         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
 241         if (unlikely(!skb))
 242                 return NULL;
 243
 244         hdr = skb_vnet_hdr(skb);
 245
 246         if (vi->mergeable_rx_bufs) {
 247                 hdr_len = sizeof hdr->mhdr;
 248                 offset = hdr_len;
 249         } else {
 250                 hdr_len = sizeof hdr->hdr;
 251                 offset = sizeof(struct padded_vnet_hdr);
 252         }
 253
 254         memcpy(hdr, p, hdr_len);
 255
 256         len -= hdr_len;
 257         p += offset;
 258
 259         copy = len;
 260         if (copy > skb_tailroom(skb))
 261                 copy = skb_tailroom(skb);
 262         memcpy(skb_put(skb, copy), p, copy);
 263
 264         len -= copy;
 265         offset += copy;
 266
 267         /*
 268          * Verify that we can indeed put this data into a skb.
 269          * This is here to handle cases when the device erroneously
 270          * tries to receive more than is possible. This is usually
 271          * the case of a broken device.
 272          */
 273         if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
 274                 net_dbg_ratelimited("%s: too much data\n", skb->dev->name);
 275                 dev_kfree_skb(skb);
 276                 return NULL;
 277         }
 278
 279         while (len) {
 280                 set_skb_frag(skb, page, offset, &len);
 281                 page = (struct page *)page->private;
 282                 offset = 0;
 283         }
 284
 285         if (page)
 286                 give_pages(rq, page);
 287
 288         return skb;
 289 }
 290
 291 static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb)
 292 {
 293         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 294         struct page *page;
 295         int num_buf, i, len;
 296
 297         num_buf = hdr->mhdr.num_buffers;
 298         while (--num_buf) {
 299                 i = skb_shinfo(skb)->nr_frags;
 300                 if (i >= MAX_SKB_FRAGS) {
 301                         pr_debug("%s: packet too long\n", skb->dev->name);
 302                         skb->dev->stats.rx_length_errors++;
 303                         return -EINVAL;
 304                 }
 305                 page = virtqueue_get_buf(rq->vq, &len);
 306                 if (!page) {
 307                         pr_debug("%s: rx error: %d buffers missing\n",
 308                                  skb->dev->name, hdr->mhdr.num_buffers);
 309                         skb->dev->stats.rx_length_errors++;
 310                         return -EINVAL;
 311                 }
 312
 313                 if (len > PAGE_SIZE)
 314                         len = PAGE_SIZE;
 315
 316                 set_skb_frag(skb, page, 0, &len);
 317
 318                 --rq->num;
 319         }
 320         return 0;
 321 }
 322
 323 static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
 324 {
 325         struct virtnet_info *vi = rq->vq->vdev->priv;
 326         struct net_device *dev = vi->dev;
 327         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 328         struct sk_buff *skb;
 329         struct page *page;
 330         struct skb_vnet_hdr *hdr;
 331
 332         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
 333                 pr_debug("%s: short packet %i\n", dev->name, len);
 334                 dev->stats.rx_length_errors++;
 335                 if (vi->mergeable_rx_bufs || vi->big_packets)
 336                         give_pages(rq, buf);
 337                 else
 338                         dev_kfree_skb(buf);
 339                 return;
 340         }
 341
 342         if (!vi->mergeable_rx_bufs && !vi->big_packets) {
 343                 skb = buf;
 344                 len -= sizeof(struct virtio_net_hdr);
 345                 skb_trim(skb, len);
 346         } else {
 347                 page = buf;
 348                 skb = page_to_skb(rq, page, len);
 349                 if (unlikely(!skb)) {
 350                         dev->stats.rx_dropped++;
 351                         give_pages(rq, page);
 352                         return;
 353                 }
 354                 if (vi->mergeable_rx_bufs)
 355                         if (receive_mergeable(rq, skb)) {
 356                                 dev_kfree_skb(skb);
 357                                 return;
 358                         }
 359         }
 360
 361         hdr = skb_vnet_hdr(skb);
 362
 363         u64_stats_update_begin(&stats->rx_syncp);
 364         stats->rx_bytes += skb->len;
 365         stats->rx_packets++;
 366         u64_stats_update_end(&stats->rx_syncp);
 367
 368         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 369                 pr_debug("Needs csum!\n");
 370                 if (!skb_partial_csum_set(skb,
 371                                           hdr->hdr.csum_start,
 372                                           hdr->hdr.csum_offset))
 373                         goto frame_err;
 374         } else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
 375                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 376         }
 377
 378         skb->protocol = eth_type_trans(skb, dev);
 379         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 380                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 381
 382         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 383                 pr_debug("GSO!\n");
 384                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 385                 case VIRTIO_NET_HDR_GSO_TCPV4:
 386                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 387                         break;
 388                 case VIRTIO_NET_HDR_GSO_UDP:
 389                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 390                         break;
 391                 case VIRTIO_NET_HDR_GSO_TCPV6:
 392                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 393                         break;
 394                 default:
 395                         net_warn_ratelimited("%s: bad gso type %u.\n",
 396                                              dev->name, hdr->hdr.gso_type);
 397                         goto frame_err;
 398                 }
 399
 400                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 401                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 402
 403                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
 404                 if (skb_shinfo(skb)->gso_size == 0) {
 405                         net_warn_ratelimited("%s: zero gso size.\n", dev->name);
 406                         goto frame_err;
 407                 }
 408
 409                 /* Header must be checked, and gso_segs computed. */
 410                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 411                 skb_shinfo(skb)->gso_segs = 0;
 412         }
 413
 414         netif_receive_skb(skb);
 415         return;
 416
 417 frame_err:
 418         dev->stats.rx_frame_errors++;
 419         dev_kfree_skb(skb);
 420 }
 421
 422 static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
 423 {
 424         struct virtnet_info *vi = rq->vq->vdev->priv;
 425         struct sk_buff *skb;
 426         struct skb_vnet_hdr *hdr;
 427         int err;
 428
 429         skb = __netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN, gfp);
 430         if (unlikely(!skb))
 431                 return -ENOMEM;
 432
 433         skb_put(skb, MAX_PACKET_LEN);
 434
 435         hdr = skb_vnet_hdr(skb);
 436         sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
 437
 438         skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 439
 440         err = virtqueue_add_buf(rq->vq, rq->sg, 0, 2, skb, gfp);
 441         if (err < 0)
 442                 dev_kfree_skb(skb);
 443
 444         return err;
 445 }
 446
 447 static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
 448 {
 449         struct page *first, *list = NULL;
 450         char *p;
 451         int i, err, offset;
 452
 453         /* page in rq->sg[MAX_SKB_FRAGS + 1] is list tail */
 454         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 455                 first = get_a_page(rq, gfp);
 456                 if (!first) {
 457                         if (list)
 458                                 give_pages(rq, list);
 459                         return -ENOMEM;
 460                 }
 461                 sg_set_buf(&rq->sg[i], page_address(first), PAGE_SIZE);
 462
 463                 /* chain new page in list head to match sg */
 464                 first->private = (unsigned long)list;
 465                 list = first;
 466         }
 467
 468         first = get_a_page(rq, gfp);
 469         if (!first) {
 470                 give_pages(rq, list);
 471                 return -ENOMEM;
 472         }
 473         p = page_address(first);
 474
 475         /* rq->sg[0], rq->sg[1] share the same page */
 476         /* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
 477         sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
 478
 479         /* rq->sg[1] for data packet, from offset */
 480         offset = sizeof(struct padded_vnet_hdr);
 481         sg_set_buf(&rq->sg[1], p + offset, PAGE_SIZE - offset);
 482
 483         /* chain first in list head */
 484         first->private = (unsigned long)list;
 485         err = virtqueue_add_buf(rq->vq, rq->sg, 0, MAX_SKB_FRAGS + 2,
 486                                 first, gfp);
 487         if (err < 0)
 488                 give_pages(rq, first);
 489
 490         return err;
 491 }
 492
 493 static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
 494 {
 495         struct page *page;
 496         int err;
 497
 498         page = get_a_page(rq, gfp);
 499         if (!page)
 500                 return -ENOMEM;
 501
 502         sg_init_one(rq->sg, page_address(page), PAGE_SIZE);
 503
 504         err = virtqueue_add_buf(rq->vq, rq->sg, 0, 1, page, gfp);
 505         if (err < 0)
 506                 give_pages(rq, page);
 507
 508         return err;
 509 }
 510
 511 /*
 512  * Returns false if we couldn't fill entirely (OOM).
 513  *
 514  * Normally run in the receive path, but can also be run from ndo_open
 515  * before we're receiving packets, or from refill_work which is
 516  * careful to disable receiving (using napi_disable).
 517  */
 518 static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
 519 {
 520         struct virtnet_info *vi = rq->vq->vdev->priv;
 521         int err;
 522         bool oom;
 523
 524         do {
 525                 if (vi->mergeable_rx_bufs)
 526                         err = add_recvbuf_mergeable(rq, gfp);
 527                 else if (vi->big_packets)
 528                         err = add_recvbuf_big(rq, gfp);
 529                 else
 530                         err = add_recvbuf_small(rq, gfp);
 531
 532                 oom = err == -ENOMEM;
 533                 if (err < 0)
 534                         break;
 535                 ++rq->num;
 536         } while (err > 0);
 537         if (unlikely(rq->num > rq->max))
 538                 rq->max = rq->num;
 539         virtqueue_kick(rq->vq);
 540         return !oom;
 541 }
 542
 543 static void skb_recv_done(struct virtqueue *rvq)
 544 {
 545         struct virtnet_info *vi = rvq->vdev->priv;
 546         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 547
 548         /* Schedule NAPI, Suppress further interrupts if successful. */
 549         if (napi_schedule_prep(&rq->napi)) {
 550                 virtqueue_disable_cb(rvq);
 551                 __napi_schedule(&rq->napi);
 552         }
 553 }
 554
 555 static void virtnet_napi_enable(struct receive_queue *rq)
 556 {
 557         napi_enable(&rq->napi);
 558
 559         /* If all buffers were filled by other side before we napi_enabled, we
 560          * won't get another interrupt, so process any outstanding packets
 561          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 562          * We synchronize against interrupts via NAPI_STATE_SCHED */
 563         if (napi_schedule_prep(&rq->napi)) {
 564                 virtqueue_disable_cb(rq->vq);
 565                 local_bh_disable();
 566                 __napi_schedule(&rq->napi);
 567                 local_bh_enable();
 568         }
 569 }
 570
 571 static void refill_work(struct work_struct *work)
 572 {
 573         struct virtnet_info *vi =
 574                 container_of(work, struct virtnet_info, refill.work);
 575         bool still_empty;
 576         int i;
 577
 578         for (i = 0; i < vi->max_queue_pairs; i++) {
 579                 struct receive_queue *rq = &vi->rq[i];
 580
 581                 napi_disable(&rq->napi);
 582                 still_empty = !try_fill_recv(rq, GFP_KERNEL);
 583                 virtnet_napi_enable(rq);
 584
 585                 /* In theory, this can happen: if we don't get any buffers in
 586                  * we will *never* try to fill again.
 587                  */
 588                 if (still_empty)
 589                         schedule_delayed_work(&vi->refill, HZ/2);
 590         }
 591 }
 592
 593 static int virtnet_poll(struct napi_struct *napi, int budget)
 594 {
 595         struct receive_queue *rq =
 596                 container_of(napi, struct receive_queue, napi);
 597         struct virtnet_info *vi = rq->vq->vdev->priv;
 598         void *buf;
 599         unsigned int len, received = 0;
 600
 601 again:
 602         while (received < budget &&
 603                (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
 604                 receive_buf(rq, buf, len);
 605                 --rq->num;
 606                 received++;
 607         }
 608
 609         if (rq->num < rq->max / 2) {
 610                 if (!try_fill_recv(rq, GFP_ATOMIC))
 611                         schedule_delayed_work(&vi->refill, 0);
 612         }
 613
 614         /* Out of packets? */
 615         if (received < budget) {
 616                 napi_complete(napi);
 617                 if (unlikely(!virtqueue_enable_cb(rq->vq)) &&
 618                     napi_schedule_prep(napi)) {
 619                         virtqueue_disable_cb(rq->vq);
 620                         __napi_schedule(napi);
 621                         goto again;
 622                 }
 623         }
 624
 625         return received;
 626 }
 627
 628 static int virtnet_open(struct net_device *dev)
 629 {
 630         struct virtnet_info *vi = netdev_priv(dev);
 631         int i;
 632
 633         for (i = 0; i < vi->max_queue_pairs; i++) {
 634                 /* Make sure we have some buffers: if oom use wq. */
 635                 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
 636                         schedule_delayed_work(&vi->refill, 0);
 637                 virtnet_napi_enable(&vi->rq[i]);
 638         }
 639
 640         return 0;
 641 }
 642
 643 static unsigned int free_old_xmit_skbs(struct send_queue *sq)
 644 {
 645         struct sk_buff *skb;
 646         unsigned int len, tot_sgs = 0;
 647         struct virtnet_info *vi = sq->vq->vdev->priv;
 648         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 649
 650         while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 651                 pr_debug("Sent skb %p\n", skb);
 652
 653                 u64_stats_update_begin(&stats->tx_syncp);
 654                 stats->tx_bytes += skb->len;
 655                 stats->tx_packets++;
 656                 u64_stats_update_end(&stats->tx_syncp);
 657
 658                 tot_sgs += skb_vnet_hdr(skb)->num_sg;
 659                 dev_kfree_skb_any(skb);
 660         }
 661         return tot_sgs;
 662 }
 663
 664 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 665 {
 666         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 667         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 668         struct virtnet_info *vi = sq->vq->vdev->priv;
 669
 670         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 671
 672         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 673                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 674                 hdr->hdr.csum_start = skb_checksum_start_offset(skb);
 675                 hdr->hdr.csum_offset = skb->csum_offset;
 676         } else {
 677                 hdr->hdr.flags = 0;
 678                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 679         }
 680
 681         if (skb_is_gso(skb)) {
 682                 hdr->hdr.hdr_len = skb_headlen(skb);
 683                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
 684                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 685                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 686                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 687                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 688                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 689                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 690                 else
 691                         BUG();
 692                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 693                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 694         } else {
 695                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 696                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
 697         }
 698
 699         hdr->mhdr.num_buffers = 0;
 700
 701         /* Encode metadata header at front. */
 702         if (vi->mergeable_rx_bufs)
 703                 sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr);
 704         else
 705                 sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);
 706
 707         hdr->num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
 708         return virtqueue_add_buf(sq->vq, sq->sg, hdr->num_sg,
 709                                  0, skb, GFP_ATOMIC);
 710 }
 711
 712 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 713 {
 714         struct virtnet_info *vi = netdev_priv(dev);
 715         int qnum = skb_get_queue_mapping(skb);
 716         struct send_queue *sq = &vi->sq[qnum];
 717         int capacity;
 718
 719         /* Free up any pending old buffers before queueing new ones. */
 720         free_old_xmit_skbs(sq);
 721
 722         /* Try to transmit */
 723         capacity = xmit_skb(sq, skb);
 724
 725         /* This can happen with OOM and indirect buffers. */
 726         if (unlikely(capacity < 0)) {
 727                 if (likely(capacity == -ENOMEM)) {
 728                         if (net_ratelimit())
 729                                 dev_warn(&dev->dev,
 730                                          "TXQ (%d) failure: out of memory\n",
 731                                          qnum);
 732                 } else {
 733                         dev->stats.tx_fifo_errors++;
 734                         if (net_ratelimit())
 735                                 dev_warn(&dev->dev,
 736                                          "Unexpected TXQ (%d) failure: %d\n",
 737                                          qnum, capacity);
 738                 }
 739                 dev->stats.tx_dropped++;
 740                 kfree_skb(skb);
 741                 return NETDEV_TX_OK;
 742         }
 743         virtqueue_kick(sq->vq);
 744
 745         /* Don't wait up for transmitted skbs to be freed. */
 746         skb_orphan(skb);
 747         nf_reset(skb);
 748
 749         /* Apparently nice girls don't return TX_BUSY; stop the queue
 750          * before it gets out of hand.  Naturally, this wastes entries. */
 751         if (capacity < 2+MAX_SKB_FRAGS) {
 752                 netif_stop_subqueue(dev, qnum);
 753                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 754                         /* More just got used, free them then recheck. */
 755                         capacity += free_old_xmit_skbs(sq);
 756                         if (capacity >= 2+MAX_SKB_FRAGS) {
 757                                 netif_start_subqueue(dev, qnum);
 758                                 virtqueue_disable_cb(sq->vq);
 759                         }
 760                 }
 761         }
 762
 763         return NETDEV_TX_OK;
 764 }
 765
 766 static int virtnet_set_mac_address(struct net_device *dev, void *p)
 767 {
 768         struct virtnet_info *vi = netdev_priv(dev);
 769         struct virtio_device *vdev = vi->vdev;
 770         int ret;
 771
 772         ret = eth_mac_addr(dev, p);
 773         if (ret)
 774                 return ret;
 775
 776         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
 777                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
 778                                   dev->dev_addr, dev->addr_len);
 779
 780         return 0;
 781 }
 782
 783 static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
 784                                                struct rtnl_link_stats64 *tot)
 785 {
 786         struct virtnet_info *vi = netdev_priv(dev);
 787         int cpu;
 788         unsigned int start;
 789
 790         for_each_possible_cpu(cpu) {
 791                 struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
 792                 u64 tpackets, tbytes, rpackets, rbytes;
 793
 794                 do {
 795                         start = u64_stats_fetch_begin_bh(&stats->tx_syncp);
 796                         tpackets = stats->tx_packets;
 797                         tbytes   = stats->tx_bytes;
 798                 } while (u64_stats_fetch_retry_bh(&stats->tx_syncp, start));
 799
 800                 do {
 801                         start = u64_stats_fetch_begin_bh(&stats->rx_syncp);
 802                         rpackets = stats->rx_packets;
 803                         rbytes   = stats->rx_bytes;
 804                 } while (u64_stats_fetch_retry_bh(&stats->rx_syncp, start));
 805
 806                 tot->rx_packets += rpackets;
 807                 tot->tx_packets += tpackets;
 808                 tot->rx_bytes   += rbytes;
 809                 tot->tx_bytes   += tbytes;
 810         }
 811
 812         tot->tx_dropped = dev->stats.tx_dropped;
 813         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
 814         tot->rx_dropped = dev->stats.rx_dropped;
 815         tot->rx_length_errors = dev->stats.rx_length_errors;
 816         tot->rx_frame_errors = dev->stats.rx_frame_errors;
 817
 818         return tot;
 819 }
 820
 821 #ifdef CONFIG_NET_POLL_CONTROLLER
 822 static void virtnet_netpoll(struct net_device *dev)
 823 {
 824         struct virtnet_info *vi = netdev_priv(dev);
 825         int i;
 826
 827         for (i = 0; i < vi->curr_queue_pairs; i++)
 828                 napi_schedule(&vi->rq[i].napi);
 829 }
 830 #endif
 831
 832 /*
 833  * Send command via the control virtqueue and check status.  Commands
 834  * supported by the hypervisor, as indicated by feature bits, should
 835  * never fail unless improperly formated.
 836  */
 837 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 838                                  struct scatterlist *data, int out, int in)
 839 {
 840         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
 841         struct virtio_net_ctrl_hdr ctrl;
 842         virtio_net_ctrl_ack status = ~0;
 843         unsigned int tmp;
 844         int i;
 845
 846         /* Caller should know better */
 847         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
 848                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
 849
 850         out++; /* Add header */
 851         in++; /* Add return status */
 852
 853         ctrl.class = class;
 854         ctrl.cmd = cmd;
 855
 856         sg_init_table(sg, out + in);
 857
 858         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
 859         for_each_sg(data, s, out + in - 2, i)
 860                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
 861         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
 862
 863         BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0);
 864
 865         virtqueue_kick(vi->cvq);
 866
 867         /*
 868          * Spin for a response, the kick causes an ioport write, trapping
 869          * into the hypervisor, so the request should be handled immediately.
 870          */
 871         while (!virtqueue_get_buf(vi->cvq, &tmp))
 872                 cpu_relax();
 873
 874         return status == VIRTIO_NET_OK;
 875 }
 876
 877 static void virtnet_ack_link_announce(struct virtnet_info *vi)
 878 {
 879         rtnl_lock();
 880         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
 881                                   VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL,
 882                                   0, 0))
 883                 dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
 884         rtnl_unlock();
 885 }
 886
 887 static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
 888 {
 889         struct scatterlist sg;
 890         struct virtio_net_ctrl_mq s;
 891         struct net_device *dev = vi->dev;
 892
 893         if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
 894                 return 0;
 895
 896         s.virtqueue_pairs = queue_pairs;
 897         sg_init_one(&sg, &s, sizeof(s));
 898
 899         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
 900                                   VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, 1, 0)){
 901                 dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
 902                          queue_pairs);
 903                 return -EINVAL;
 904         } else
 905                 vi->curr_queue_pairs = queue_pairs;
 906
 907         return 0;
 908 }
 909
 910 static int virtnet_close(struct net_device *dev)
 911 {
 912         struct virtnet_info *vi = netdev_priv(dev);
 913         int i;
 914
 915         /* Make sure refill_work doesn't re-enable napi! */
 916         cancel_delayed_work_sync(&vi->refill);
 917
 918         for (i = 0; i < vi->max_queue_pairs; i++)
 919                 napi_disable(&vi->rq[i].napi);
 920
 921         return 0;
 922 }
 923
 924 static void virtnet_set_rx_mode(struct net_device *dev)
 925 {
 926         struct virtnet_info *vi = netdev_priv(dev);
 927         struct scatterlist sg[2];
 928         u8 promisc, allmulti;
 929         struct virtio_net_ctrl_mac *mac_data;
 930         struct netdev_hw_addr *ha;
 931         int uc_count;
 932         int mc_count;
 933         void *buf;
 934         int i;
 935
 936         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
 937         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
 938                 return;
 939
 940         promisc = ((dev->flags & IFF_PROMISC) != 0);
 941         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
 942
 943         sg_init_one(sg, &promisc, sizeof(promisc));
 944
 945         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 946                                   VIRTIO_NET_CTRL_RX_PROMISC,
 947                                   sg, 1, 0))
 948                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
 949                          promisc ? "en" : "dis");
 950
 951         sg_init_one(sg, &allmulti, sizeof(allmulti));
 952
 953         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 954                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
 955                                   sg, 1, 0))
 956                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
 957                          allmulti ? "en" : "dis");
 958
 959         uc_count = netdev_uc_count(dev);
 960         mc_count = netdev_mc_count(dev);
 961         /* MAC filter - use one buffer for both lists */
 962         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
 963                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
 964         mac_data = buf;
 965         if (!buf) {
 966                 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
 967                 return;
 968         }
 969
 970         sg_init_table(sg, 2);
 971
 972         /* Store the unicast list and count in the front of the buffer */
 973         mac_data->entries = uc_count;
 974         i = 0;
 975         netdev_for_each_uc_addr(ha, dev)
 976                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 977
 978         sg_set_buf(&sg[0], mac_data,
 979                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
 980
 981         /* multicast list and count fill the end */
 982         mac_data = (void *)&mac_data->macs[uc_count][0];
 983
 984         mac_data->entries = mc_count;
 985         i = 0;
 986         netdev_for_each_mc_addr(ha, dev)
 987                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 988
 989         sg_set_buf(&sg[1], mac_data,
 990                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
 991
 992         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
 993                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
 994                                   sg, 2, 0))
 995                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
 996
 997         kfree(buf);
 998 }
 999
1000 static int virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
1001 {
1002         struct virtnet_info *vi = netdev_priv(dev);
1003         struct scatterlist sg;
1004
1005         sg_init_one(&sg, &vid, sizeof(vid));
1006
1007         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1008                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
1009                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
1010         return 0;
1011 }
1012
1013 static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
1014 {
1015         struct virtnet_info *vi = netdev_priv(dev);
1016         struct scatterlist sg;
1017
1018         sg_init_one(&sg, &vid, sizeof(vid));
1019
1020         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
1021                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
1022                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
1023         return 0;
1024 }
1025
1026 static void virtnet_set_affinity(struct virtnet_info *vi, bool set)
1027 {
1028         int i;
1029
1030         /* In multiqueue mode, when the number of cpu is equal to the number of
1031          * queue pairs, we let the queue pairs to be private to one cpu by
1032          * setting the affinity hint to eliminate the contention.
1033          */
1034         if ((vi->curr_queue_pairs == 1 ||
1035              vi->max_queue_pairs != num_online_cpus()) && set) {
1036                 if (vi->affinity_hint_set)
1037                         set = false;
1038                 else
1039                         return;
1040         }
1041
1042         for (i = 0; i < vi->max_queue_pairs; i++) {
1043                 int cpu = set ? i : -1;
1044                 virtqueue_set_affinity(vi->rq[i].vq, cpu);
1045                 virtqueue_set_affinity(vi->sq[i].vq, cpu);
1046         }
1047
1048         if (set)
1049                 vi->affinity_hint_set = true;
1050         else
1051                 vi->affinity_hint_set = false;
1052 }
1053
1054 static void virtnet_get_ringparam(struct net_device *dev,
1055                                 struct ethtool_ringparam *ring)
1056 {
1057         struct virtnet_info *vi = netdev_priv(dev);
1058
1059         ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
1060         ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
1061         ring->rx_pending = ring->rx_max_pending;
1062         ring->tx_pending = ring->tx_max_pending;
1063 }
1064
1065
1066 static void virtnet_get_drvinfo(struct net_device *dev,
1067                                 struct ethtool_drvinfo *info)
1068 {
1069         struct virtnet_info *vi = netdev_priv(dev);
1070         struct virtio_device *vdev = vi->vdev;
1071
1072         strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
1073         strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
1074         strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
1075
1076 }
1077
1078 /* TODO: Eliminate OOO packets during switching */
1079 static int virtnet_set_channels(struct net_device *dev,
1080                                 struct ethtool_channels *channels)
1081 {
1082         struct virtnet_info *vi = netdev_priv(dev);
1083         u16 queue_pairs = channels->combined_count;
1084         int err;
1085
1086         /* We don't support separate rx/tx channels.
1087          * We don't allow setting 'other' channels.
1088          */
1089         if (channels->rx_count || channels->tx_count || channels->other_count)
1090                 return -EINVAL;
1091
1092         if (queue_pairs > vi->max_queue_pairs)
1093                 return -EINVAL;
1094
1095         err = virtnet_set_queues(vi, queue_pairs);
1096         if (!err) {
1097                 netif_set_real_num_tx_queues(dev, queue_pairs);
1098                 netif_set_real_num_rx_queues(dev, queue_pairs);
1099
1100                 virtnet_set_affinity(vi, true);
1101         }
1102
1103         return err;
1104 }
1105
1106 static void virtnet_get_channels(struct net_device *dev,
1107                                  struct ethtool_channels *channels)
1108 {
1109         struct virtnet_info *vi = netdev_priv(dev);
1110
1111         channels->combined_count = vi->curr_queue_pairs;
1112         channels->max_combined = vi->max_queue_pairs;
1113         channels->max_other = 0;
1114         channels->rx_count = 0;
1115         channels->tx_count = 0;
1116         channels->other_count = 0;
1117 }
1118
1119 static const struct ethtool_ops virtnet_ethtool_ops = {
1120         .get_drvinfo = virtnet_get_drvinfo,
1121         .get_link = ethtool_op_get_link,
1122         .get_ringparam = virtnet_get_ringparam,
1123         .set_channels = virtnet_set_channels,
1124         .get_channels = virtnet_get_channels,
1125 };
1126
1127 #define MIN_MTU 68
1128 #define MAX_MTU 65535
1129
1130 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
1131 {
1132         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
1133                 return -EINVAL;
1134         dev->mtu = new_mtu;
1135         return 0;
1136 }
1137
1138 /* To avoid contending a lock hold by a vcpu who would exit to host, select the
1139  * txq based on the processor id.
1140  * TODO: handle cpu hotplug.
1141  */
1142 static u16 virtnet_select_queue(struct net_device *dev, struct sk_buff *skb)
1143 {
1144         int txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) :
1145                   smp_processor_id();
1146
1147         while (unlikely(txq >= dev->real_num_tx_queues))
1148                 txq -= dev->real_num_tx_queues;
1149
1150         return txq;
1151 }
1152
1153 static const struct net_device_ops virtnet_netdev = {
1154         .ndo_open            = virtnet_open,
1155         .ndo_stop            = virtnet_close,
1156         .ndo_start_xmit      = start_xmit,
1157         .ndo_validate_addr   = eth_validate_addr,
1158         .ndo_set_mac_address = virtnet_set_mac_address,
1159         .ndo_set_rx_mode     = virtnet_set_rx_mode,
1160         .ndo_change_mtu      = virtnet_change_mtu,
1161         .ndo_get_stats64     = virtnet_stats,
1162         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
1163         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
1164         .ndo_select_queue     = virtnet_select_queue,
1165 #ifdef CONFIG_NET_POLL_CONTROLLER
1166         .ndo_poll_controller = virtnet_netpoll,
1167 #endif
1168 };
1169
1170 static void virtnet_config_changed_work(struct work_struct *work)
1171 {
1172         struct virtnet_info *vi =
1173                 container_of(work, struct virtnet_info, config_work);
1174         u16 v;
1175
1176         mutex_lock(&vi->config_lock);
1177         if (!vi->config_enable)
1178                 goto done;
1179
1180         if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
1181                               offsetof(struct virtio_net_config, status),
1182                               &v) < 0)
1183                 goto done;
1184
1185         if (v & VIRTIO_NET_S_ANNOUNCE) {
1186                 netdev_notify_peers(vi->dev);
1187                 virtnet_ack_link_announce(vi);
1188         }
1189
1190         /* Ignore unknown (future) status bits */
1191         v &= VIRTIO_NET_S_LINK_UP;
1192
1193         if (vi->status == v)
1194                 goto done;
1195
1196         vi->status = v;
1197
1198         if (vi->status & VIRTIO_NET_S_LINK_UP) {
1199                 netif_carrier_on(vi->dev);
1200                 netif_tx_wake_all_queues(vi->dev);
1201         } else {
1202                 netif_carrier_off(vi->dev);
1203                 netif_tx_stop_all_queues(vi->dev);
1204         }
1205 done:
1206         mutex_unlock(&vi->config_lock);
1207 }
1208
1209 static void virtnet_config_changed(struct virtio_device *vdev)
1210 {
1211         struct virtnet_info *vi = vdev->priv;
1212
1213         schedule_work(&vi->config_work);
1214 }
1215
1216 static void virtnet_free_queues(struct virtnet_info *vi)
1217 {
1218         kfree(vi->rq);
1219         kfree(vi->sq);
1220 }
1221
1222 static void free_receive_bufs(struct virtnet_info *vi)
1223 {
1224         int i;
1225
1226         for (i = 0; i < vi->max_queue_pairs; i++) {
1227                 while (vi->rq[i].pages)
1228                         __free_pages(get_a_page(&vi->rq[i], GFP_KERNEL), 0);
1229         }
1230 }
1231
1232 static void free_unused_bufs(struct virtnet_info *vi)
1233 {
1234         void *buf;
1235         int i;
1236
1237         for (i = 0; i < vi->max_queue_pairs; i++) {
1238                 struct virtqueue *vq = vi->sq[i].vq;
1239                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL)
1240                         dev_kfree_skb(buf);
1241         }
1242
1243         for (i = 0; i < vi->max_queue_pairs; i++) {
1244                 struct virtqueue *vq = vi->rq[i].vq;
1245
1246                 while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
1247                         if (vi->mergeable_rx_bufs || vi->big_packets)
1248                                 give_pages(&vi->rq[i], buf);
1249                         else
1250                                 dev_kfree_skb(buf);
1251                         --vi->rq[i].num;
1252                 }
1253                 BUG_ON(vi->rq[i].num != 0);
1254         }
1255 }
1256
1257 static void virtnet_del_vqs(struct virtnet_info *vi)
1258 {
1259         struct virtio_device *vdev = vi->vdev;
1260
1261         virtnet_set_affinity(vi, false);
1262
1263         vdev->config->del_vqs(vdev);
1264
1265         virtnet_free_queues(vi);
1266 }
1267
1268 static int virtnet_find_vqs(struct virtnet_info *vi)
1269 {
1270         vq_callback_t **callbacks;
1271         struct virtqueue **vqs;
1272         int ret = -ENOMEM;
1273         int i, total_vqs;
1274         const char **names;
1275
1276         /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
1277          * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by
1278          * possible control vq.
1279          */
1280         total_vqs = vi->max_queue_pairs * 2 +
1281                     virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
1282
1283         /* Allocate space for find_vqs parameters */
1284         vqs = kzalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
1285         if (!vqs)
1286                 goto err_vq;
1287         callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
1288         if (!callbacks)
1289                 goto err_callback;
1290         names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
1291         if (!names)
1292                 goto err_names;
1293
1294         /* Parameters for control virtqueue, if any */
1295         if (vi->has_cvq) {
1296                 callbacks[total_vqs - 1] = NULL;
1297                 names[total_vqs - 1] = "control";
1298         }
1299
1300         /* Allocate/initialize parameters for send/receive virtqueues */
1301         for (i = 0; i < vi->max_queue_pairs; i++) {
1302                 callbacks[rxq2vq(i)] = skb_recv_done;
1303                 callbacks[txq2vq(i)] = skb_xmit_done;
1304                 sprintf(vi->rq[i].name, "input.%d", i);
1305                 sprintf(vi->sq[i].name, "output.%d", i);
1306                 names[rxq2vq(i)] = vi->rq[i].name;
1307                 names[txq2vq(i)] = vi->sq[i].name;
1308         }
1309
1310         ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
1311                                          names);
1312         if (ret)
1313                 goto err_find;
1314
1315         if (vi->has_cvq) {
1316                 vi->cvq = vqs[total_vqs - 1];
1317                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
1318                         vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
1319         }
1320
1321         for (i = 0; i < vi->max_queue_pairs; i++) {
1322                 vi->rq[i].vq = vqs[rxq2vq(i)];
1323                 vi->sq[i].vq = vqs[txq2vq(i)];
1324         }
1325
1326         kfree(names);
1327         kfree(callbacks);
1328         kfree(vqs);
1329
1330         return 0;
1331
1332 err_find:
1333         kfree(names);
1334 err_names:
1335         kfree(callbacks);
1336 err_callback:
1337         kfree(vqs);
1338 err_vq:
1339         return ret;
1340 }
1341
1342 static int virtnet_alloc_queues(struct virtnet_info *vi)
1343 {
1344         int i;
1345
1346         vi->sq = kzalloc(sizeof(*vi->sq) * vi->max_queue_pairs, GFP_KERNEL);
1347         if (!vi->sq)
1348                 goto err_sq;
1349         vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
1350         if (!vi->rq)
1351                 goto err_rq;
1352
1353         INIT_DELAYED_WORK(&vi->refill, refill_work);
1354         for (i = 0; i < vi->max_queue_pairs; i++) {
1355                 vi->rq[i].pages = NULL;
1356                 netif_napi_add(vi->dev, &vi->rq[i].napi, virtnet_poll,
1357                                napi_weight);
1358
1359                 sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
1360                 sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
1361         }
1362
1363         return 0;
1364
1365 err_rq:
1366         kfree(vi->sq);
1367 err_sq:
1368         return -ENOMEM;
1369 }
1370
1371 static int init_vqs(struct virtnet_info *vi)
1372 {
1373         int ret;
1374
1375         /* Allocate send & receive queues */
1376         ret = virtnet_alloc_queues(vi);
1377         if (ret)
1378                 goto err;
1379
1380         ret = virtnet_find_vqs(vi);
1381         if (ret)
1382                 goto err_free;
1383
1384         virtnet_set_affinity(vi, true);
1385         return 0;
1386
1387 err_free:
1388         virtnet_free_queues(vi);
1389 err:
1390         return ret;
1391 }
1392
1393 static int virtnet_probe(struct virtio_device *vdev)
1394 {
1395         int i, err;
1396         struct net_device *dev;
1397         struct virtnet_info *vi;
1398         u16 max_queue_pairs;
1399
1400         /* Find if host supports multiqueue virtio_net device */
1401         err = virtio_config_val(vdev, VIRTIO_NET_F_MQ,
1402                                 offsetof(struct virtio_net_config,
1403                                 max_virtqueue_pairs), &max_queue_pairs);
1404
1405         /* We need at least 2 queue's */
1406         if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1407             max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1408             !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1409                 max_queue_pairs = 1;
1410
1411         /* Allocate ourselves a network device with room for our info */
1412         dev = alloc_etherdev_mq(sizeof(struct virtnet_info), max_queue_pairs);
1413         if (!dev)
1414                 return -ENOMEM;
1415
1416         /* Set up network device as normal. */
1417         dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
1418         dev->netdev_ops = &virtnet_netdev;
1419         dev->features = NETIF_F_HIGHDMA;
1420
1421         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
1422         SET_NETDEV_DEV(dev, &vdev->dev);
1423
1424         /* Do we support "hardware" checksums? */
1425         if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
1426                 /* This opens up the world of extra features. */
1427                 dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1428                 if (csum)
1429                         dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1430
1431                 if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
1432                         dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
1433                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
1434                 }
1435                 /* Individual feature bits: what can host handle? */
1436                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
1437                         dev->hw_features |= NETIF_F_TSO;
1438                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
1439                         dev->hw_features |= NETIF_F_TSO6;
1440                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
1441                         dev->hw_features |= NETIF_F_TSO_ECN;
1442                 if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
1443                         dev->hw_features |= NETIF_F_UFO;
1444
1445                 if (gso)
1446                         dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
1447                 /* (!csum && gso) case will be fixed by register_netdev() */
1448         }
1449
1450         /* Configuration may specify what MAC to use.  Otherwise random. */
1451         if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
1452                                   offsetof(struct virtio_net_config, mac),
1453                                   dev->dev_addr, dev->addr_len) < 0)
1454                 eth_hw_addr_random(dev);
1455
1456         /* Set up our device-specific information */
1457         vi = netdev_priv(dev);
1458         vi->dev = dev;
1459         vi->vdev = vdev;
1460         vdev->priv = vi;
1461         vi->stats = alloc_percpu(struct virtnet_stats);
1462         err = -ENOMEM;
1463         if (vi->stats == NULL)
1464                 goto free;
1465
1466         mutex_init(&vi->config_lock);
1467         vi->config_enable = true;
1468         INIT_WORK(&vi->config_work, virtnet_config_changed_work);
1469
1470         /* If we can receive ANY GSO packets, we must allocate large ones. */
1471         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
1472             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
1473             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
1474                 vi->big_packets = true;
1475
1476         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
1477                 vi->mergeable_rx_bufs = true;
1478
1479         if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
1480                 vi->has_cvq = true;
1481
1482         /* Use single tx/rx queue pair as default */
1483         vi->curr_queue_pairs = 1;
1484         vi->max_queue_pairs = max_queue_pairs;
1485
1486         /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
1487         err = init_vqs(vi);
1488         if (err)
1489                 goto free_stats;
1490
1491         netif_set_real_num_tx_queues(dev, 1);
1492         netif_set_real_num_rx_queues(dev, 1);
1493
1494         err = register_netdev(dev);
1495         if (err) {
1496                 pr_debug("virtio_net: registering device failed\n");
1497                 goto free_vqs;
1498         }
1499
1500         /* Last of all, set up some receive buffers. */
1501         for (i = 0; i < vi->max_queue_pairs; i++) {
1502                 try_fill_recv(&vi->rq[i], GFP_KERNEL);
1503
1504                 /* If we didn't even get one input buffer, we're useless. */
1505                 if (vi->rq[i].num == 0) {
1506                         free_unused_bufs(vi);
1507                         err = -ENOMEM;
1508                         goto free_recv_bufs;
1509                 }
1510         }
1511
1512         /* Assume link up if device can't report link status,
1513            otherwise get link status from config. */
1514         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
1515                 netif_carrier_off(dev);
1516                 schedule_work(&vi->config_work);
1517         } else {
1518                 vi->status = VIRTIO_NET_S_LINK_UP;
1519                 netif_carrier_on(dev);
1520         }
1521
1522         pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
1523                  dev->name, max_queue_pairs);
1524
1525         return 0;
1526
1527 free_recv_bufs:
1528         free_receive_bufs(vi);
1529         unregister_netdev(dev);
1530 free_vqs:
1531         cancel_delayed_work_sync(&vi->refill);
1532         virtnet_del_vqs(vi);
1533 free_stats:
1534         free_percpu(vi->stats);
1535 free:
1536         free_netdev(dev);
1537         return err;
1538 }
1539
1540 static void remove_vq_common(struct virtnet_info *vi)
1541 {
1542         vi->vdev->config->reset(vi->vdev);
1543
1544         /* Free unused buffers in both send and recv, if any. */
1545         free_unused_bufs(vi);
1546
1547         free_receive_bufs(vi);
1548
1549         virtnet_del_vqs(vi);
1550 }
1551
1552 static void virtnet_remove(struct virtio_device *vdev)
1553 {
1554         struct virtnet_info *vi = vdev->priv;
1555
1556         /* Prevent config work handler from accessing the device. */
1557         mutex_lock(&vi->config_lock);
1558         vi->config_enable = false;
1559         mutex_unlock(&vi->config_lock);
1560
1561         unregister_netdev(vi->dev);
1562
1563         remove_vq_common(vi);
1564
1565         flush_work(&vi->config_work);
1566
1567         free_percpu(vi->stats);
1568         free_netdev(vi->dev);
1569 }
1570
1571 #ifdef CONFIG_PM
1572 static int virtnet_freeze(struct virtio_device *vdev)
1573 {
1574         struct virtnet_info *vi = vdev->priv;
1575         int i;
1576
1577         /* Prevent config work handler from accessing the device */
1578         mutex_lock(&vi->config_lock);
1579         vi->config_enable = false;
1580         mutex_unlock(&vi->config_lock);
1581
1582         netif_device_detach(vi->dev);
1583         cancel_delayed_work_sync(&vi->refill);
1584
1585         if (netif_running(vi->dev))
1586                 for (i = 0; i < vi->max_queue_pairs; i++) {
1587                         napi_disable(&vi->rq[i].napi);
1588                         netif_napi_del(&vi->rq[i].napi);
1589                 }
1590
1591         remove_vq_common(vi);
1592
1593         flush_work(&vi->config_work);
1594
1595         return 0;
1596 }
1597
1598 static int virtnet_restore(struct virtio_device *vdev)
1599 {
1600         struct virtnet_info *vi = vdev->priv;
1601         int err, i;
1602
1603         err = init_vqs(vi);
1604         if (err)
1605                 return err;
1606
1607         if (netif_running(vi->dev))
1608                 for (i = 0; i < vi->max_queue_pairs; i++)
1609                         virtnet_napi_enable(&vi->rq[i]);
1610
1611         netif_device_attach(vi->dev);
1612
1613         for (i = 0; i < vi->max_queue_pairs; i++)
1614                 if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
1615                         schedule_delayed_work(&vi->refill, 0);
1616
1617         mutex_lock(&vi->config_lock);
1618         vi->config_enable = true;
1619         mutex_unlock(&vi->config_lock);
1620
1621         virtnet_set_queues(vi, vi->curr_queue_pairs);
1622
1623         return 0;
1624 }
1625 #endif
1626
1627 static struct virtio_device_id id_table[] = {
1628         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1629         { 0 },
1630 };
1631
1632 static unsigned int features[] = {
1633         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1634         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1635         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1636         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1637         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1638         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1639         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1640         VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
1641 };
1642
1643 static struct virtio_driver virtio_net_driver = {
1644         .feature_table = features,
1645         .feature_table_size = ARRAY_SIZE(features),
1646         .driver.name =  KBUILD_MODNAME,
1647         .driver.owner = THIS_MODULE,
1648         .id_table =     id_table,
1649         .probe =        virtnet_probe,
1650         .remove =       virtnet_remove,
1651         .config_changed = virtnet_config_changed,
1652 #ifdef CONFIG_PM
1653         .freeze =       virtnet_freeze,
1654         .restore =      virtnet_restore,
1655 #endif
1656 };
1657
1658 static int __init init(void)
1659 {
1660         return register_virtio_driver(&virtio_net_driver);
1661 }
1662
1663 static void __exit fini(void)
1664 {
1665         unregister_virtio_driver(&virtio_net_driver);
1666 }
1667 module_init(init);
1668 module_exit(fini);
1669
1670 MODULE_DEVICE_TABLE(virtio, id_table);
1671 MODULE_DESCRIPTION("Virtio network driver");
1672 MODULE_LICENSE("GPL");