SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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
  29 static int napi_weight = 128;
  30 module_param(napi_weight, int, 0444);
  31
  32 static int csum = 1, gso = 1;
  33 module_param(csum, bool, 0444);
  34 module_param(gso, bool, 0444);
  35
  36 /* FIXME: MTU in config. */
  37 #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
  38 #define GOOD_COPY_LEN   128
  39
  40 #define VIRTNET_SEND_COMMAND_SG_MAX    2
  41
  42 struct virtnet_info
  43 {
  44         struct virtio_device *vdev;
  45         struct virtqueue *rvq, *svq, *cvq;
  46         struct net_device *dev;
  47         struct napi_struct napi;
  48         unsigned int status;
  49
  50         /* Number of input buffers, and max we've ever had. */
  51         unsigned int num, max;
  52
  53         /* I like... big packets and I cannot lie! */
  54         bool big_packets;
  55
  56         /* Host will merge rx buffers for big packets (shake it! shake it!) */
  57         bool mergeable_rx_bufs;
  58
  59         /* Send queue. */
  60         struct sk_buff_head send;
  61
  62         /* Work struct for refilling if we run low on memory. */
  63         struct delayed_work refill;
  64
  65         /* Chain pages by the private ptr. */
  66         struct page *pages;
  67 };
  68
  69 struct skb_vnet_hdr {
  70         union {
  71                 struct virtio_net_hdr hdr;
  72                 struct virtio_net_hdr_mrg_rxbuf mhdr;
  73         };
  74         unsigned int num_sg;
  75 };
  76
  77 struct padded_vnet_hdr {
  78         struct virtio_net_hdr hdr;
  79         /*
  80          * virtio_net_hdr should be in a separated sg buffer because of a
  81          * QEMU bug, and data sg buffer shares same page with this header sg.
  82          * This padding makes next sg 16 byte aligned after virtio_net_hdr.
  83          */
  84         char padding[6];
  85 };
  86
  87 static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
  88 {
  89         return (struct skb_vnet_hdr *)skb->cb;
  90 }
  91
  92 /*
  93  * private is used to chain pages for big packets, put the whole
  94  * most recent used list in the beginning for reuse
  95  */
  96 static void give_pages(struct virtnet_info *vi, struct page *page)
  97 {
  98         struct page *end;
  99
 100         /* Find end of list, sew whole thing into vi->pages. */
 101         for (end = page; end->private; end = (struct page *)end->private);
 102         end->private = (unsigned long)vi->pages;
 103         vi->pages = page;
 104 }
 105
 106 static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
 107 {
 108         struct page *p = vi->pages;
 109
 110         if (p) {
 111                 vi->pages = (struct page *)p->private;
 112                 /* clear private here, it is used to chain pages */
 113                 p->private = 0;
 114         } else
 115                 p = alloc_page(gfp_mask);
 116         return p;
 117 }
 118
 119 static void skb_xmit_done(struct virtqueue *svq)
 120 {
 121         struct virtnet_info *vi = svq->vdev->priv;
 122
 123         /* Suppress further interrupts. */
 124         svq->vq_ops->disable_cb(svq);
 125
 126         /* We were probably waiting for more output buffers. */
 127         netif_wake_queue(vi->dev);
 128 }
 129
 130 static void set_skb_frag(struct sk_buff *skb, struct page *page,
 131                          unsigned int offset, unsigned int *len)
 132 {
 133         int i = skb_shinfo(skb)->nr_frags;
 134         skb_frag_t *f;
 135
 136         f = &skb_shinfo(skb)->frags[i];
 137         f->size = min((unsigned)PAGE_SIZE - offset, *len);
 138         f->page_offset = offset;
 139         f->page = page;
 140
 141         skb->data_len += f->size;
 142         skb->len += f->size;
 143         skb_shinfo(skb)->nr_frags++;
 144         *len -= f->size;
 145 }
 146
 147 static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 148                                    struct page *page, unsigned int len)
 149 {
 150         struct sk_buff *skb;
 151         struct skb_vnet_hdr *hdr;
 152         unsigned int copy, hdr_len, offset;
 153         char *p;
 154
 155         p = page_address(page);
 156
 157         /* copy small packet so we can reuse these pages for small data */
 158         skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN);
 159         if (unlikely(!skb))
 160                 return NULL;
 161
 162         hdr = skb_vnet_hdr(skb);
 163
 164         if (vi->mergeable_rx_bufs) {
 165                 hdr_len = sizeof hdr->mhdr;
 166                 offset = hdr_len;
 167         } else {
 168                 hdr_len = sizeof hdr->hdr;
 169                 offset = sizeof(struct padded_vnet_hdr);
 170         }
 171
 172         memcpy(hdr, p, hdr_len);
 173
 174         len -= hdr_len;
 175         p += offset;
 176
 177         copy = len;
 178         if (copy > skb_tailroom(skb))
 179                 copy = skb_tailroom(skb);
 180         memcpy(skb_put(skb, copy), p, copy);
 181
 182         len -= copy;
 183         offset += copy;
 184
 185         while (len) {
 186                 set_skb_frag(skb, page, offset, &len);
 187                 page = (struct page *)page->private;
 188                 offset = 0;
 189         }
 190
 191         if (page)
 192                 give_pages(vi, page);
 193
 194         return skb;
 195 }
 196
 197 static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb)
 198 {
 199         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 200         struct page *page;
 201         int num_buf, i, len;
 202
 203         num_buf = hdr->mhdr.num_buffers;
 204         while (--num_buf) {
 205                 i = skb_shinfo(skb)->nr_frags;
 206                 if (i >= MAX_SKB_FRAGS) {
 207                         pr_debug("%s: packet too long\n", skb->dev->name);
 208                         skb->dev->stats.rx_length_errors++;
 209                         return -EINVAL;
 210                 }
 211
 212                 page = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
 213                 if (!page) {
 214                         pr_debug("%s: rx error: %d buffers missing\n",
 215                                  skb->dev->name, hdr->mhdr.num_buffers);
 216                         skb->dev->stats.rx_length_errors++;
 217                         return -EINVAL;
 218                 }
 219                 if (len > PAGE_SIZE)
 220                         len = PAGE_SIZE;
 221
 222                 set_skb_frag(skb, page, 0, &len);
 223
 224                 --vi->num;
 225         }
 226         return 0;
 227 }
 228
 229 static void receive_buf(struct net_device *dev, void *buf, unsigned int len)
 230 {
 231         struct virtnet_info *vi = netdev_priv(dev);
 232         struct sk_buff *skb;
 233         struct page *page;
 234         struct skb_vnet_hdr *hdr;
 235
 236         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
 237                 pr_debug("%s: short packet %i\n", dev->name, len);
 238                 dev->stats.rx_length_errors++;
 239                 if (vi->mergeable_rx_bufs || vi->big_packets)
 240                         give_pages(vi, buf);
 241                 else
 242                         dev_kfree_skb(buf);
 243                 return;
 244         }
 245
 246         if (!vi->mergeable_rx_bufs && !vi->big_packets) {
 247                 skb = buf;
 248                 len -= sizeof(struct virtio_net_hdr);
 249                 skb_trim(skb, len);
 250         } else {
 251                 page = buf;
 252                 skb = page_to_skb(vi, page, len);
 253                 if (unlikely(!skb)) {
 254                         dev->stats.rx_dropped++;
 255                         give_pages(vi, page);
 256                         return;
 257                 }
 258                 if (vi->mergeable_rx_bufs)
 259                         if (receive_mergeable(vi, skb)) {
 260                                 dev_kfree_skb(skb);
 261                                 return;
 262                         }
 263         }
 264
 265         hdr = skb_vnet_hdr(skb);
 266         skb->truesize += skb->data_len;
 267         dev->stats.rx_bytes += skb->len;
 268         dev->stats.rx_packets++;
 269
 270         if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 271                 pr_debug("Needs csum!\n");
 272                 if (!skb_partial_csum_set(skb,
 273                                           hdr->hdr.csum_start,
 274                                           hdr->hdr.csum_offset))
 275                         goto frame_err;
 276         }
 277
 278         skb->protocol = eth_type_trans(skb, dev);
 279         pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
 280                  ntohs(skb->protocol), skb->len, skb->pkt_type);
 281
 282         if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 283                 pr_debug("GSO!\n");
 284                 switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 285                 case VIRTIO_NET_HDR_GSO_TCPV4:
 286                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 287                         break;
 288                 case VIRTIO_NET_HDR_GSO_UDP:
 289                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 290                         break;
 291                 case VIRTIO_NET_HDR_GSO_TCPV6:
 292                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 293                         break;
 294                 default:
 295                         if (net_ratelimit())
 296                                 printk(KERN_WARNING "%s: bad gso type %u.\n",
 297                                        dev->name, hdr->hdr.gso_type);
 298                         goto frame_err;
 299                 }
 300
 301                 if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 302                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 303
 304                 skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
 305                 if (skb_shinfo(skb)->gso_size == 0) {
 306                         if (net_ratelimit())
 307                                 printk(KERN_WARNING "%s: zero gso size.\n",
 308                                        dev->name);
 309                         goto frame_err;
 310                 }
 311
 312                 /* Header must be checked, and gso_segs computed. */
 313                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 314                 skb_shinfo(skb)->gso_segs = 0;
 315         }
 316
 317         netif_receive_skb(skb);
 318         return;
 319
 320 frame_err:
 321         dev->stats.rx_frame_errors++;
 322         dev_kfree_skb(skb);
 323 }
 324
 325 static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
 326 {
 327         struct sk_buff *skb;
 328         struct skb_vnet_hdr *hdr;
 329         struct scatterlist sg[2];
 330         int err;
 331
 332         skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN);
 333         if (unlikely(!skb))
 334                 return -ENOMEM;
 335
 336         skb_put(skb, MAX_PACKET_LEN);
 337
 338         hdr = skb_vnet_hdr(skb);
 339         sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr);
 340
 341         skb_to_sgvec(skb, sg + 1, 0, skb->len);
 342
 343         err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 2, skb);
 344         if (err < 0)
 345                 dev_kfree_skb(skb);
 346
 347         return err;
 348 }
 349
 350 static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
 351 {
 352         struct scatterlist sg[MAX_SKB_FRAGS + 2];
 353         struct page *first, *list = NULL;
 354         char *p;
 355         int i, err, offset;
 356
 357         /* page in sg[MAX_SKB_FRAGS + 1] is list tail */
 358         for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 359                 first = get_a_page(vi, gfp);
 360                 if (!first) {
 361                         if (list)
 362                                 give_pages(vi, list);
 363                         return -ENOMEM;
 364                 }
 365                 sg_set_buf(&sg[i], page_address(first), PAGE_SIZE);
 366
 367                 /* chain new page in list head to match sg */
 368                 first->private = (unsigned long)list;
 369                 list = first;
 370         }
 371
 372         first = get_a_page(vi, gfp);
 373         if (!first) {
 374                 give_pages(vi, list);
 375                 return -ENOMEM;
 376         }
 377         p = page_address(first);
 378
 379         /* sg[0], sg[1] share the same page */
 380         /* a separated sg[0] for  virtio_net_hdr only during to QEMU bug*/
 381         sg_set_buf(&sg[0], p, sizeof(struct virtio_net_hdr));
 382
 383         /* sg[1] for data packet, from offset */
 384         offset = sizeof(struct padded_vnet_hdr);
 385         sg_set_buf(&sg[1], p + offset, PAGE_SIZE - offset);
 386
 387         /* chain first in list head */
 388         first->private = (unsigned long)list;
 389         err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, MAX_SKB_FRAGS + 2,
 390                                        first);
 391         if (err < 0)
 392                 give_pages(vi, first);
 393
 394         return err;
 395 }
 396
 397 static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
 398 {
 399         struct page *page;
 400         struct scatterlist sg;
 401         int err;
 402
 403         page = get_a_page(vi, gfp);
 404         if (!page)
 405                 return -ENOMEM;
 406
 407         sg_init_one(&sg, page_address(page), PAGE_SIZE);
 408
 409         err = vi->rvq->vq_ops->add_buf(vi->rvq, &sg, 0, 1, page);
 410         if (err < 0)
 411                 give_pages(vi, page);
 412
 413         return err;
 414 }
 415
 416 /* Returns false if we couldn't fill entirely (OOM). */
 417 static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
 418 {
 419         int err;
 420         bool oom = false;
 421
 422         do {
 423                 if (vi->mergeable_rx_bufs)
 424                         err = add_recvbuf_mergeable(vi, gfp);
 425                 else if (vi->big_packets)
 426                         err = add_recvbuf_big(vi, gfp);
 427                 else
 428                         err = add_recvbuf_small(vi, gfp);
 429
 430                 if (err < 0) {
 431                         oom = true;
 432                         break;
 433                 }
 434                 ++vi->num;
 435         } while (err > 0);
 436         if (unlikely(vi->num > vi->max))
 437                 vi->max = vi->num;
 438         vi->rvq->vq_ops->kick(vi->rvq);
 439         return !oom;
 440 }
 441
 442 static void skb_recv_done(struct virtqueue *rvq)
 443 {
 444         struct virtnet_info *vi = rvq->vdev->priv;
 445         /* Schedule NAPI, Suppress further interrupts if successful. */
 446         if (napi_schedule_prep(&vi->napi)) {
 447                 rvq->vq_ops->disable_cb(rvq);
 448                 __napi_schedule(&vi->napi);
 449         }
 450 }
 451
 452 static void refill_work(struct work_struct *work)
 453 {
 454         struct virtnet_info *vi;
 455         bool still_empty;
 456
 457         vi = container_of(work, struct virtnet_info, refill.work);
 458         napi_disable(&vi->napi);
 459         still_empty = !try_fill_recv(vi, GFP_KERNEL);
 460         napi_enable(&vi->napi);
 461
 462         /* In theory, this can happen: if we don't get any buffers in
 463          * we will *never* try to fill again. */
 464         if (still_empty)
 465                 schedule_delayed_work(&vi->refill, HZ/2);
 466 }
 467
 468 static int virtnet_poll(struct napi_struct *napi, int budget)
 469 {
 470         struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
 471         void *buf;
 472         unsigned int len, received = 0;
 473
 474 again:
 475         while (received < budget &&
 476                (buf = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
 477                 receive_buf(vi->dev, buf, len);
 478                 --vi->num;
 479                 received++;
 480         }
 481
 482         if (vi->num < vi->max / 2) {
 483                 if (!try_fill_recv(vi, GFP_ATOMIC))
 484                         schedule_delayed_work(&vi->refill, 0);
 485         }
 486
 487         /* Out of packets? */
 488         if (received < budget) {
 489                 napi_complete(napi);
 490                 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) &&
 491                     napi_schedule_prep(napi)) {
 492                         vi->rvq->vq_ops->disable_cb(vi->rvq);
 493                         __napi_schedule(napi);
 494                         goto again;
 495                 }
 496         }
 497
 498         return received;
 499 }
 500
 501 static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
 502 {
 503         struct sk_buff *skb;
 504         unsigned int len, tot_sgs = 0;
 505
 506         while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
 507                 pr_debug("Sent skb %p\n", skb);
 508                 __skb_unlink(skb, &vi->send);
 509                 vi->dev->stats.tx_bytes += skb->len;
 510                 vi->dev->stats.tx_packets++;
 511                 tot_sgs += skb_vnet_hdr(skb)->num_sg;
 512                 dev_kfree_skb_any(skb);
 513         }
 514         return tot_sgs;
 515 }
 516
 517 static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
 518 {
 519         struct scatterlist sg[2+MAX_SKB_FRAGS];
 520         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 521         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 522
 523         sg_init_table(sg, 2+MAX_SKB_FRAGS);
 524
 525         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 526
 527         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 528                 hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 529                 hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb);
 530                 hdr->hdr.csum_offset = skb->csum_offset;
 531         } else {
 532                 hdr->hdr.flags = 0;
 533                 hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 534         }
 535
 536         if (skb_is_gso(skb)) {
 537                 hdr->hdr.hdr_len = skb_headlen(skb);
 538                 hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
 539                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 540                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 541                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
 542                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 543                 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 544                         hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 545                 else
 546                         BUG();
 547                 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
 548                         hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 549         } else {
 550                 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 551                 hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
 552         }
 553
 554         hdr->mhdr.num_buffers = 0;
 555
 556         /* Encode metadata header at front. */
 557         if (vi->mergeable_rx_bufs)
 558                 sg_set_buf(sg, &hdr->mhdr, sizeof hdr->mhdr);
 559         else
 560                 sg_set_buf(sg, &hdr->hdr, sizeof hdr->hdr);
 561
 562         hdr->num_sg = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
 563         return vi->svq->vq_ops->add_buf(vi->svq, sg, hdr->num_sg, 0, skb);
 564 }
 565
 566 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 567 {
 568         struct virtnet_info *vi = netdev_priv(dev);
 569         int capacity;
 570
 571 again:
 572         /* Free up any pending old buffers before queueing new ones. */
 573         free_old_xmit_skbs(vi);
 574
 575         /* Try to transmit */
 576         capacity = xmit_skb(vi, skb);
 577
 578         /* This can happen with OOM and indirect buffers. */
 579         if (unlikely(capacity < 0)) {
 580                 netif_stop_queue(dev);
 581                 dev_warn(&dev->dev, "Unexpected full queue\n");
 582                 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
 583                         vi->svq->vq_ops->disable_cb(vi->svq);
 584                         netif_start_queue(dev);
 585                         goto again;
 586                 }
 587                 return NETDEV_TX_BUSY;
 588         }
 589         vi->svq->vq_ops->kick(vi->svq);
 590
 591         /*
 592          * Put new one in send queue.  You'd expect we'd need this before
 593          * xmit_skb calls add_buf(), since the callback can be triggered
 594          * immediately after that.  But since the callback just triggers
 595          * another call back here, normal network xmit locking prevents the
 596          * race.
 597          */
 598         __skb_queue_head(&vi->send, skb);
 599
 600         /* Don't wait up for transmitted skbs to be freed. */
 601         skb_orphan(skb);
 602         nf_reset(skb);
 603
 604         /* Apparently nice girls don't return TX_BUSY; stop the queue
 605          * before it gets out of hand.  Naturally, this wastes entries. */
 606         if (capacity < 2+MAX_SKB_FRAGS) {
 607                 netif_stop_queue(dev);
 608                 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
 609                         /* More just got used, free them then recheck. */
 610                         capacity += free_old_xmit_skbs(vi);
 611                         if (capacity >= 2+MAX_SKB_FRAGS) {
 612                                 netif_start_queue(dev);
 613                                 vi->svq->vq_ops->disable_cb(vi->svq);
 614                         }
 615                 }
 616         }
 617
 618         return NETDEV_TX_OK;
 619 }
 620
 621 static int virtnet_set_mac_address(struct net_device *dev, void *p)
 622 {
 623         struct virtnet_info *vi = netdev_priv(dev);
 624         struct virtio_device *vdev = vi->vdev;
 625         int ret;
 626
 627         ret = eth_mac_addr(dev, p);
 628         if (ret)
 629                 return ret;
 630
 631         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
 632                 vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
 633                                   dev->dev_addr, dev->addr_len);
 634
 635         return 0;
 636 }
 637
 638 #ifdef CONFIG_NET_POLL_CONTROLLER
 639 static void virtnet_netpoll(struct net_device *dev)
 640 {
 641         struct virtnet_info *vi = netdev_priv(dev);
 642
 643         napi_schedule(&vi->napi);
 644 }
 645 #endif
 646
 647 static int virtnet_open(struct net_device *dev)
 648 {
 649         struct virtnet_info *vi = netdev_priv(dev);
 650
 651         napi_enable(&vi->napi);
 652
 653         /* If all buffers were filled by other side before we napi_enabled, we
 654          * won't get another interrupt, so process any outstanding packets
 655          * now.  virtnet_poll wants re-enable the queue, so we disable here.
 656          * We synchronize against interrupts via NAPI_STATE_SCHED */
 657         if (napi_schedule_prep(&vi->napi)) {
 658                 vi->rvq->vq_ops->disable_cb(vi->rvq);
 659                 __napi_schedule(&vi->napi);
 660         }
 661         return 0;
 662 }
 663
 664 /*
 665  * Send command via the control virtqueue and check status.  Commands
 666  * supported by the hypervisor, as indicated by feature bits, should
 667  * never fail unless improperly formated.
 668  */
 669 static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 670                                  struct scatterlist *data, int out, int in)
 671 {
 672         struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
 673         struct virtio_net_ctrl_hdr ctrl;
 674         virtio_net_ctrl_ack status = ~0;
 675         unsigned int tmp;
 676         int i;
 677
 678         /* Caller should know better */
 679         BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
 680                 (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
 681
 682         out++; /* Add header */
 683         in++; /* Add return status */
 684
 685         ctrl.class = class;
 686         ctrl.cmd = cmd;
 687
 688         sg_init_table(sg, out + in);
 689
 690         sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
 691         for_each_sg(data, s, out + in - 2, i)
 692                 sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
 693         sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
 694
 695         BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) < 0);
 696
 697         vi->cvq->vq_ops->kick(vi->cvq);
 698
 699         /*
 700          * Spin for a response, the kick causes an ioport write, trapping
 701          * into the hypervisor, so the request should be handled immediately.
 702          */
 703         while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp))
 704                 cpu_relax();
 705
 706         return status == VIRTIO_NET_OK;
 707 }
 708
 709 static int virtnet_close(struct net_device *dev)
 710 {
 711         struct virtnet_info *vi = netdev_priv(dev);
 712
 713         napi_disable(&vi->napi);
 714
 715         return 0;
 716 }
 717
 718 static int virtnet_set_tx_csum(struct net_device *dev, u32 data)
 719 {
 720         struct virtnet_info *vi = netdev_priv(dev);
 721         struct virtio_device *vdev = vi->vdev;
 722
 723         if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
 724                 return -ENOSYS;
 725
 726         return ethtool_op_set_tx_hw_csum(dev, data);
 727 }
 728
 729 static void virtnet_set_rx_mode(struct net_device *dev)
 730 {
 731         struct virtnet_info *vi = netdev_priv(dev);
 732         struct scatterlist sg[2];
 733         u8 promisc, allmulti;
 734         struct virtio_net_ctrl_mac *mac_data;
 735         struct dev_addr_list *addr;
 736         struct netdev_hw_addr *ha;
 737         int uc_count;
 738         int mc_count;
 739         void *buf;
 740         int i;
 741
 742         /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
 743         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
 744                 return;
 745
 746         promisc = ((dev->flags & IFF_PROMISC) != 0);
 747         allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
 748
 749         sg_init_one(sg, &promisc, sizeof(promisc));
 750
 751         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 752                                   VIRTIO_NET_CTRL_RX_PROMISC,
 753                                   sg, 1, 0))
 754                 dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
 755                          promisc ? "en" : "dis");
 756
 757         sg_init_one(sg, &allmulti, sizeof(allmulti));
 758
 759         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
 760                                   VIRTIO_NET_CTRL_RX_ALLMULTI,
 761                                   sg, 1, 0))
 762                 dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
 763                          allmulti ? "en" : "dis");
 764
 765         uc_count = netdev_uc_count(dev);
 766         mc_count = netdev_mc_count(dev);
 767         /* MAC filter - use one buffer for both lists */
 768         buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
 769                       (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
 770         mac_data = buf;
 771         if (!buf) {
 772                 dev_warn(&dev->dev, "No memory for MAC address buffer\n");
 773                 return;
 774         }
 775
 776         sg_init_table(sg, 2);
 777
 778         /* Store the unicast list and count in the front of the buffer */
 779         mac_data->entries = uc_count;
 780         i = 0;
 781         netdev_for_each_uc_addr(ha, dev)
 782                 memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
 783
 784         sg_set_buf(&sg[0], mac_data,
 785                    sizeof(mac_data->entries) + (uc_count * ETH_ALEN));
 786
 787         /* multicast list and count fill the end */
 788         mac_data = (void *)&mac_data->macs[uc_count][0];
 789
 790         mac_data->entries = mc_count;
 791         addr = dev->mc_list;
 792         for (i = 0; i < mc_count; i++, addr = addr->next)
 793                 memcpy(&mac_data->macs[i][0], addr->da_addr, ETH_ALEN);
 794
 795         sg_set_buf(&sg[1], mac_data,
 796                    sizeof(mac_data->entries) + (mc_count * ETH_ALEN));
 797
 798         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
 799                                   VIRTIO_NET_CTRL_MAC_TABLE_SET,
 800                                   sg, 2, 0))
 801                 dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
 802
 803         kfree(buf);
 804 }
 805
 806 static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
 807 {
 808         struct virtnet_info *vi = netdev_priv(dev);
 809         struct scatterlist sg;
 810
 811         sg_init_one(&sg, &vid, sizeof(vid));
 812
 813         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
 814                                   VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
 815                 dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
 816 }
 817
 818 static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
 819 {
 820         struct virtnet_info *vi = netdev_priv(dev);
 821         struct scatterlist sg;
 822
 823         sg_init_one(&sg, &vid, sizeof(vid));
 824
 825         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
 826                                   VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
 827                 dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
 828 }
 829
 830 static const struct ethtool_ops virtnet_ethtool_ops = {
 831         .set_tx_csum = virtnet_set_tx_csum,
 832         .set_sg = ethtool_op_set_sg,
 833         .set_tso = ethtool_op_set_tso,
 834         .set_ufo = ethtool_op_set_ufo,
 835         .get_link = ethtool_op_get_link,
 836 };
 837
 838 #define MIN_MTU 68
 839 #define MAX_MTU 65535
 840
 841 static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
 842 {
 843         if (new_mtu < MIN_MTU || new_mtu > MAX_MTU)
 844                 return -EINVAL;
 845         dev->mtu = new_mtu;
 846         return 0;
 847 }
 848
 849 static const struct net_device_ops virtnet_netdev = {
 850         .ndo_open            = virtnet_open,
 851         .ndo_stop            = virtnet_close,
 852         .ndo_start_xmit      = start_xmit,
 853         .ndo_validate_addr   = eth_validate_addr,
 854         .ndo_set_mac_address = virtnet_set_mac_address,
 855         .ndo_set_rx_mode     = virtnet_set_rx_mode,
 856         .ndo_change_mtu      = virtnet_change_mtu,
 857         .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid,
 858         .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
 859 #ifdef CONFIG_NET_POLL_CONTROLLER
 860         .ndo_poll_controller = virtnet_netpoll,
 861 #endif
 862 };
 863
 864 static void virtnet_update_status(struct virtnet_info *vi)
 865 {
 866         u16 v;
 867
 868         if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS))
 869                 return;
 870
 871         vi->vdev->config->get(vi->vdev,
 872                               offsetof(struct virtio_net_config, status),
 873                               &v, sizeof(v));
 874
 875         /* Ignore unknown (future) status bits */
 876         v &= VIRTIO_NET_S_LINK_UP;
 877
 878         if (vi->status == v)
 879                 return;
 880
 881         vi->status = v;
 882
 883         if (vi->status & VIRTIO_NET_S_LINK_UP) {
 884                 netif_carrier_on(vi->dev);
 885                 netif_wake_queue(vi->dev);
 886         } else {
 887                 netif_carrier_off(vi->dev);
 888                 netif_stop_queue(vi->dev);
 889         }
 890 }
 891
 892 static void virtnet_config_changed(struct virtio_device *vdev)
 893 {
 894         struct virtnet_info *vi = vdev->priv;
 895
 896         virtnet_update_status(vi);
 897 }
 898
 899 static int virtnet_probe(struct virtio_device *vdev)
 900 {
 901         int err;
 902         struct net_device *dev;
 903         struct virtnet_info *vi;
 904         struct virtqueue *vqs[3];
 905         vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
 906         const char *names[] = { "input", "output", "control" };
 907         int nvqs;
 908
 909         /* Allocate ourselves a network device with room for our info */
 910         dev = alloc_etherdev(sizeof(struct virtnet_info));
 911         if (!dev)
 912                 return -ENOMEM;
 913
 914         /* Set up network device as normal. */
 915         dev->netdev_ops = &virtnet_netdev;
 916         dev->features = NETIF_F_HIGHDMA;
 917         SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
 918         SET_NETDEV_DEV(dev, &vdev->dev);
 919
 920         /* Do we support "hardware" checksums? */
 921         if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
 922                 /* This opens up the world of extra features. */
 923                 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
 924                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
 925                         dev->features |= NETIF_F_TSO | NETIF_F_UFO
 926                                 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
 927                 }
 928                 /* Individual feature bits: what can host handle? */
 929                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
 930                         dev->features |= NETIF_F_TSO;
 931                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
 932                         dev->features |= NETIF_F_TSO6;
 933                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
 934                         dev->features |= NETIF_F_TSO_ECN;
 935                 if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
 936                         dev->features |= NETIF_F_UFO;
 937         }
 938
 939         /* Configuration may specify what MAC to use.  Otherwise random. */
 940         if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
 941                 vdev->config->get(vdev,
 942                                   offsetof(struct virtio_net_config, mac),
 943                                   dev->dev_addr, dev->addr_len);
 944         } else
 945                 random_ether_addr(dev->dev_addr);
 946
 947         /* Set up our device-specific information */
 948         vi = netdev_priv(dev);
 949         netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
 950         vi->dev = dev;
 951         vi->vdev = vdev;
 952         vdev->priv = vi;
 953         vi->pages = NULL;
 954         INIT_DELAYED_WORK(&vi->refill, refill_work);
 955
 956         /* If we can receive ANY GSO packets, we must allocate large ones. */
 957         if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
 958             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
 959             virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
 960                 vi->big_packets = true;
 961
 962         if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
 963                 vi->mergeable_rx_bufs = true;
 964
 965         /* We expect two virtqueues, receive then send,
 966          * and optionally control. */
 967         nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
 968
 969         err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
 970         if (err)
 971                 goto free;
 972
 973         vi->rvq = vqs[0];
 974         vi->svq = vqs[1];
 975
 976         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
 977                 vi->cvq = vqs[2];
 978
 979                 if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
 980                         dev->features |= NETIF_F_HW_VLAN_FILTER;
 981         }
 982
 983         /* Initialize our empty send queue. */
 984         skb_queue_head_init(&vi->send);
 985
 986         err = register_netdev(dev);
 987         if (err) {
 988                 pr_debug("virtio_net: registering device failed\n");
 989                 goto free_vqs;
 990         }
 991
 992         /* Last of all, set up some receive buffers. */
 993         try_fill_recv(vi, GFP_KERNEL);
 994
 995         /* If we didn't even get one input buffer, we're useless. */
 996         if (vi->num == 0) {
 997                 err = -ENOMEM;
 998                 goto unregister;
 999         }
1000
1001         vi->status = VIRTIO_NET_S_LINK_UP;
1002         virtnet_update_status(vi);
1003         netif_carrier_on(dev);
1004
1005         pr_debug("virtnet: registered device %s\n", dev->name);
1006         return 0;
1007
1008 unregister:
1009         unregister_netdev(dev);
1010         cancel_delayed_work_sync(&vi->refill);
1011 free_vqs:
1012         vdev->config->del_vqs(vdev);
1013 free:
1014         free_netdev(dev);
1015         return err;
1016 }
1017
1018 static void free_unused_bufs(struct virtnet_info *vi)
1019 {
1020         void *buf;
1021         while (1) {
1022                 buf = vi->rvq->vq_ops->detach_unused_buf(vi->rvq);
1023                 if (!buf)
1024                         break;
1025                 if (vi->mergeable_rx_bufs || vi->big_packets)
1026                         give_pages(vi, buf);
1027                 else
1028                         dev_kfree_skb(buf);
1029                 --vi->num;
1030         }
1031         BUG_ON(vi->num != 0);
1032 }
1033
1034 static void __devexit virtnet_remove(struct virtio_device *vdev)
1035 {
1036         struct virtnet_info *vi = vdev->priv;
1037
1038         /* Stop all the virtqueues. */
1039         vdev->config->reset(vdev);
1040
1041         /* Free our skbs in send queue, if any. */
1042         __skb_queue_purge(&vi->send);
1043
1044         unregister_netdev(vi->dev);
1045         cancel_delayed_work_sync(&vi->refill);
1046         free_unused_bufs(vi);
1047
1048         vdev->config->del_vqs(vi->vdev);
1049
1050         while (vi->pages)
1051                 __free_pages(get_a_page(vi, GFP_KERNEL), 0);
1052
1053         free_netdev(vi->dev);
1054 }
1055
1056 static struct virtio_device_id id_table[] = {
1057         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
1058         { 0 },
1059 };
1060
1061 static unsigned int features[] = {
1062         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
1063         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1064         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1065         VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
1066         VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO,
1067         VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1068         VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1069 };
1070
1071 static struct virtio_driver virtio_net_driver = {
1072         .feature_table = features,
1073         .feature_table_size = ARRAY_SIZE(features),
1074         .driver.name =  KBUILD_MODNAME,
1075         .driver.owner = THIS_MODULE,
1076         .id_table =     id_table,
1077         .probe =        virtnet_probe,
1078         .remove =       __devexit_p(virtnet_remove),
1079         .config_changed = virtnet_config_changed,
1080 };
1081
1082 static int __init init(void)
1083 {
1084         return register_virtio_driver(&virtio_net_driver);
1085 }
1086
1087 static void __exit fini(void)
1088 {
1089         unregister_virtio_driver(&virtio_net_driver);
1090 }
1091 module_init(init);
1092 module_exit(fini);
1093
1094 MODULE_DEVICE_TABLE(virtio, id_table);
1095 MODULE_DESCRIPTION("Virtio network driver");
1096 MODULE_LICENSE("GPL");