hw/virtio-net.c

   1 /*
   2  * Virtio Network Device
   3  *
   4  * Copyright IBM, Corp. 2007
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "virtio.h"
  15 #include "net.h"
  16 #include "qemu-timer.h"
  17 #include "virtio-net.h"
  18
  19 #define VIRTIO_NET_VM_VERSION    6
  20
  21 #define MAC_TABLE_ENTRIES    32
  22 #define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
  23
  24 typedef struct VirtIONet
  25 {
  26     VirtIODevice vdev;
  27     uint8_t mac[ETH_ALEN];
  28     uint16_t status;
  29     VirtQueue *rx_vq;
  30     VirtQueue *tx_vq;
  31     VirtQueue *ctrl_vq;
  32     VLANClientState *vc;
  33     QEMUTimer *tx_timer;
  34     int tx_timer_active;
  35     int mergeable_rx_bufs;
  36     int promisc;
  37     int allmulti;
  38     struct {
  39         int in_use;
  40         uint8_t *macs;
  41     } mac_table;
  42     uint32_t *vlans;
  43 } VirtIONet;
  44
  45 /* TODO
  46  * - we could suppress RX interrupt if we were so inclined.
  47  */
  48
  49 static VirtIONet *to_virtio_net(VirtIODevice *vdev)
  50 {
  51     return (VirtIONet *)vdev;
  52 }
  53
  54 static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
  55 {
  56     VirtIONet *n = to_virtio_net(vdev);
  57     struct virtio_net_config netcfg;
  58
  59     netcfg.status = n->status;
  60     memcpy(netcfg.mac, n->mac, ETH_ALEN);
  61     memcpy(config, &netcfg, sizeof(netcfg));
  62 }
  63
  64 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
  65 {
  66     VirtIONet *n = to_virtio_net(vdev);
  67     struct virtio_net_config netcfg;
  68
  69     memcpy(&netcfg, config, sizeof(netcfg));
  70
  71     if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
  72         memcpy(n->mac, netcfg.mac, ETH_ALEN);
  73         qemu_format_nic_info_str(n->vc, n->mac);
  74     }
  75 }
  76
  77 static void virtio_net_set_link_status(VLANClientState *vc)
  78 {
  79     VirtIONet *n = vc->opaque;
  80     uint16_t old_status = n->status;
  81
  82     if (vc->link_down)
  83         n->status &= ~VIRTIO_NET_S_LINK_UP;
  84     else
  85         n->status |= VIRTIO_NET_S_LINK_UP;
  86
  87     if (n->status != old_status)
  88         virtio_notify_config(&n->vdev);
  89 }
  90
  91 static void virtio_net_reset(VirtIODevice *vdev)
  92 {
  93     VirtIONet *n = to_virtio_net(vdev);
  94
  95     /* Reset back to compatibility mode */
  96     n->promisc = 1;
  97     n->allmulti = 0;
  98
  99     /* Flush any MAC and VLAN filter table state */
 100     n->mac_table.in_use = 0;
 101     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
 102     memset(n->vlans, 0, MAX_VLAN >> 3);
 103 }
 104
 105 static uint32_t virtio_net_get_features(VirtIODevice *vdev)
 106 {
 107     uint32_t features = (1 << VIRTIO_NET_F_MAC) |
 108                         (1 << VIRTIO_NET_F_STATUS) |
 109                         (1 << VIRTIO_NET_F_CTRL_VQ) |
 110                         (1 << VIRTIO_NET_F_CTRL_RX) |
 111                         (1 << VIRTIO_NET_F_CTRL_VLAN);
 112
 113     return features;
 114 }
 115
 116 static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
 117 {
 118     uint32_t features = 0;
 119
 120     /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
 121      * but also these: */
 122     features |= (1 << VIRTIO_NET_F_MAC);
 123     features |= (1 << VIRTIO_NET_F_GUEST_CSUM);
 124     features |= (1 << VIRTIO_NET_F_GUEST_TSO4);
 125     features |= (1 << VIRTIO_NET_F_GUEST_TSO6);
 126     features |= (1 << VIRTIO_NET_F_GUEST_ECN);
 127
 128     return features & virtio_net_get_features(vdev);
 129 }
 130
 131 static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
 132 {
 133     VirtIONet *n = to_virtio_net(vdev);
 134
 135     n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
 136 }
 137
 138 static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
 139                                      VirtQueueElement *elem)
 140 {
 141     uint8_t on;
 142
 143     if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {
 144         fprintf(stderr, "virtio-net ctrl invalid rx mode command\n");
 145         exit(1);
 146     }
 147
 148     on = ldub_p(elem->out_sg[1].iov_base);
 149
 150     if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)
 151         n->promisc = on;
 152     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
 153         n->allmulti = on;
 154     else
 155         return VIRTIO_NET_ERR;
 156
 157     return VIRTIO_NET_OK;
 158 }
 159
 160 static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
 161                                  VirtQueueElement *elem)
 162 {
 163     struct virtio_net_ctrl_mac mac_data;
 164
 165     if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET || elem->out_num != 3 ||
 166         elem->out_sg[1].iov_len < sizeof(mac_data) ||
 167         elem->out_sg[2].iov_len < sizeof(mac_data))
 168         return VIRTIO_NET_ERR;
 169
 170     n->mac_table.in_use = 0;
 171     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
 172
 173     mac_data.entries = ldl_le_p(elem->out_sg[1].iov_base);
 174
 175     if (sizeof(mac_data.entries) +
 176         (mac_data.entries * ETH_ALEN) > elem->out_sg[1].iov_len)
 177         return VIRTIO_NET_ERR;
 178
 179     if (mac_data.entries <= MAC_TABLE_ENTRIES) {
 180         memcpy(n->mac_table.macs, elem->out_sg[1].iov_base + sizeof(mac_data),
 181                mac_data.entries * ETH_ALEN);
 182         n->mac_table.in_use += mac_data.entries;
 183     } else {
 184         n->promisc = 1;
 185         return VIRTIO_NET_OK;
 186     }
 187
 188     mac_data.entries = ldl_le_p(elem->out_sg[2].iov_base);
 189
 190     if (sizeof(mac_data.entries) +
 191         (mac_data.entries * ETH_ALEN) > elem->out_sg[2].iov_len)
 192         return VIRTIO_NET_ERR;
 193
 194     if (mac_data.entries) {
 195         if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
 196             memcpy(n->mac_table.macs + (n->mac_table.in_use * ETH_ALEN),
 197                    elem->out_sg[2].iov_base + sizeof(mac_data),
 198                    mac_data.entries * ETH_ALEN);
 199             n->mac_table.in_use += mac_data.entries;
 200         } else
 201             n->allmulti = 1;
 202     }
 203
 204     return VIRTIO_NET_OK;
 205 }
 206
 207 static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
 208                                         VirtQueueElement *elem)
 209 {
 210     uint16_t vid;
 211
 212     if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(vid)) {
 213         fprintf(stderr, "virtio-net ctrl invalid vlan command\n");
 214         return VIRTIO_NET_ERR;
 215     }
 216
 217     vid = lduw_le_p(elem->out_sg[1].iov_base);
 218
 219     if (vid >= MAX_VLAN)
 220         return VIRTIO_NET_ERR;
 221
 222     if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
 223         n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
 224     else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
 225         n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
 226     else
 227         return VIRTIO_NET_ERR;
 228
 229     return VIRTIO_NET_OK;
 230 }
 231
 232 static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 233 {
 234     VirtIONet *n = to_virtio_net(vdev);
 235     struct virtio_net_ctrl_hdr ctrl;
 236     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
 237     VirtQueueElement elem;
 238
 239     while (virtqueue_pop(vq, &elem)) {
 240         if ((elem.in_num < 1) || (elem.out_num < 1)) {
 241             fprintf(stderr, "virtio-net ctrl missing headers\n");
 242             exit(1);
 243         }
 244
 245         if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
 246             elem.in_sg[elem.in_num - 1].iov_len < sizeof(status)) {
 247             fprintf(stderr, "virtio-net ctrl header not in correct element\n");
 248             exit(1);
 249         }
 250
 251         ctrl.class = ldub_p(elem.out_sg[0].iov_base);
 252         ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
 253
 254         if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)
 255             status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);
 256         else if (ctrl.class == VIRTIO_NET_CTRL_MAC)
 257             status = virtio_net_handle_mac(n, ctrl.cmd, &elem);
 258         else if (ctrl.class == VIRTIO_NET_CTRL_VLAN)
 259             status = virtio_net_handle_vlan_table(n, ctrl.cmd, &elem);
 260
 261         stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
 262
 263         virtqueue_push(vq, &elem, sizeof(status));
 264         virtio_notify(vdev, vq);
 265     }
 266 }
 267
 268 /* RX */
 269
 270 static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
 271 {
 272 }
 273
 274 static int do_virtio_net_can_receive(VirtIONet *n, int bufsize)
 275 {
 276     if (!virtio_queue_ready(n->rx_vq) ||
 277         !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 278         return 0;
 279
 280     if (virtio_queue_empty(n->rx_vq) ||
 281         (n->mergeable_rx_bufs &&
 282          !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
 283         virtio_queue_set_notification(n->rx_vq, 1);
 284         return 0;
 285     }
 286
 287     virtio_queue_set_notification(n->rx_vq, 0);
 288     return 1;
 289 }
 290
 291 static int virtio_net_can_receive(void *opaque)
 292 {
 293     VirtIONet *n = opaque;
 294
 295     return do_virtio_net_can_receive(n, VIRTIO_NET_MAX_BUFSIZE);
 296 }
 297
 298 static int iov_fill(struct iovec *iov, int iovcnt, const void *buf, int count)
 299 {
 300     int offset, i;
 301
 302     offset = i = 0;
 303     while (offset < count && i < iovcnt) {
 304         int len = MIN(iov[i].iov_len, count - offset);
 305         memcpy(iov[i].iov_base, buf + offset, len);
 306         offset += len;
 307         i++;
 308     }
 309
 310     return offset;
 311 }
 312
 313 static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
 314                           const void *buf, size_t size, size_t hdr_len)
 315 {
 316     struct virtio_net_hdr *hdr = iov[0].iov_base;
 317     int offset = 0;
 318
 319     hdr->flags = 0;
 320     hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
 321
 322     /* We only ever receive a struct virtio_net_hdr from the tapfd,
 323      * but we may be passing along a larger header to the guest.
 324      */
 325     iov[0].iov_base += hdr_len;
 326     iov[0].iov_len  -= hdr_len;
 327
 328     return offset;
 329 }
 330
 331 static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
 332 {
 333     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 334     static const uint8_t vlan[] = {0x81, 0x00};
 335     uint8_t *ptr = (uint8_t *)buf;
 336     int i;
 337
 338     if (n->promisc)
 339         return 1;
 340
 341 #ifdef TAP_VNET_HDR
 342     if (tap_has_vnet_hdr(n->vc->vlan->first_client))
 343         ptr += sizeof(struct virtio_net_hdr);
 344 #endif
 345
 346     if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
 347         int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
 348         if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
 349             return 0;
 350     }
 351
 352     if ((ptr[0] & 1) && n->allmulti)
 353         return 1;
 354
 355     if (!memcmp(ptr, bcast, sizeof(bcast)))
 356         return 1;
 357
 358     if (!memcmp(ptr, n->mac, ETH_ALEN))
 359         return 1;
 360
 361     for (i = 0; i < n->mac_table.in_use; i++) {
 362         if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN))
 363             return 1;
 364     }
 365
 366     return 0;
 367 }
 368
 369 static void virtio_net_receive(void *opaque, const uint8_t *buf, int size)
 370 {
 371     VirtIONet *n = opaque;
 372     struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
 373     size_t hdr_len, offset, i;
 374
 375     if (!do_virtio_net_can_receive(n, size))
 376         return;
 377
 378     if (!receive_filter(n, buf, size))
 379         return;
 380
 381     /* hdr_len refers to the header we supply to the guest */
 382     hdr_len = n->mergeable_rx_bufs ?
 383         sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
 384
 385     offset = i = 0;
 386
 387     while (offset < size) {
 388         VirtQueueElement elem;
 389         int len, total;
 390         struct iovec sg[VIRTQUEUE_MAX_SIZE];
 391
 392         len = total = 0;
 393
 394         if ((i != 0 && !n->mergeable_rx_bufs) ||
 395             virtqueue_pop(n->rx_vq, &elem) == 0) {
 396             if (i == 0)
 397                 return;
 398             fprintf(stderr, "virtio-net truncating packet\n");
 399             exit(1);
 400         }
 401
 402         if (elem.in_num < 1) {
 403             fprintf(stderr, "virtio-net receive queue contains no in buffers\n");
 404             exit(1);
 405         }
 406
 407         if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != hdr_len) {
 408             fprintf(stderr, "virtio-net header not in first element\n");
 409             exit(1);
 410         }
 411
 412         memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num);
 413
 414         if (i == 0) {
 415             if (n->mergeable_rx_bufs)
 416                 mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base;
 417
 418             offset += receive_header(n, sg, elem.in_num,
 419                                      buf + offset, size - offset, hdr_len);
 420             total += hdr_len;
 421         }
 422
 423         /* copy in packet.  ugh */
 424         len = iov_fill(sg, elem.in_num,
 425                        buf + offset, size - offset);
 426         total += len;
 427
 428         /* signal other side */
 429         virtqueue_fill(n->rx_vq, &elem, total, i++);
 430
 431         offset += len;
 432     }
 433
 434     if (mhdr)
 435         mhdr->num_buffers = i;
 436
 437     virtqueue_flush(n->rx_vq, i);
 438     virtio_notify(&n->vdev, n->rx_vq);
 439 }
 440
 441 /* TX */
 442 static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
 443 {
 444     VirtQueueElement elem;
 445     int has_vnet_hdr = 0;
 446
 447     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 448         return;
 449
 450     while (virtqueue_pop(vq, &elem)) {
 451         ssize_t len = 0;
 452         unsigned int out_num = elem.out_num;
 453         struct iovec *out_sg = &elem.out_sg[0];
 454         unsigned hdr_len;
 455
 456         /* hdr_len refers to the header received from the guest */
 457         hdr_len = n->mergeable_rx_bufs ?
 458             sizeof(struct virtio_net_hdr_mrg_rxbuf) :
 459             sizeof(struct virtio_net_hdr);
 460
 461         if (out_num < 1 || out_sg->iov_len != hdr_len) {
 462             fprintf(stderr, "virtio-net header not in first element\n");
 463             exit(1);
 464         }
 465
 466         /* ignore the header if GSO is not supported */
 467         if (!has_vnet_hdr) {
 468             out_num--;
 469             out_sg++;
 470             len += hdr_len;
 471         } else if (n->mergeable_rx_bufs) {
 472             /* tapfd expects a struct virtio_net_hdr */
 473             hdr_len -= sizeof(struct virtio_net_hdr);
 474             out_sg->iov_len -= hdr_len;
 475             len += hdr_len;
 476         }
 477
 478         len += qemu_sendv_packet(n->vc, out_sg, out_num);
 479
 480         virtqueue_push(vq, &elem, len);
 481         virtio_notify(&n->vdev, vq);
 482     }
 483 }
 484
 485 static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq)
 486 {
 487     VirtIONet *n = to_virtio_net(vdev);
 488
 489     if (n->tx_timer_active) {
 490         virtio_queue_set_notification(vq, 1);
 491         qemu_del_timer(n->tx_timer);
 492         n->tx_timer_active = 0;
 493         virtio_net_flush_tx(n, vq);
 494     } else {
 495         qemu_mod_timer(n->tx_timer,
 496                        qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
 497         n->tx_timer_active = 1;
 498         virtio_queue_set_notification(vq, 0);
 499     }
 500 }
 501
 502 static void virtio_net_tx_timer(void *opaque)
 503 {
 504     VirtIONet *n = opaque;
 505
 506     n->tx_timer_active = 0;
 507
 508     /* Just in case the driver is not ready on more */
 509     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 510         return;
 511
 512     virtio_queue_set_notification(n->tx_vq, 1);
 513     virtio_net_flush_tx(n, n->tx_vq);
 514 }
 515
 516 static void virtio_net_save(QEMUFile *f, void *opaque)
 517 {
 518     VirtIONet *n = opaque;
 519
 520     virtio_save(&n->vdev, f);
 521
 522     qemu_put_buffer(f, n->mac, ETH_ALEN);
 523     qemu_put_be32(f, n->tx_timer_active);
 524     qemu_put_be32(f, n->mergeable_rx_bufs);
 525     qemu_put_be16(f, n->status);
 526     qemu_put_be32(f, n->promisc);
 527     qemu_put_be32(f, n->allmulti);
 528     qemu_put_be32(f, n->mac_table.in_use);
 529     qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
 530     qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
 531 }
 532
 533 static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
 534 {
 535     VirtIONet *n = opaque;
 536
 537     if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
 538         return -EINVAL;
 539
 540     virtio_load(&n->vdev, f);
 541
 542     qemu_get_buffer(f, n->mac, ETH_ALEN);
 543     n->tx_timer_active = qemu_get_be32(f);
 544     n->mergeable_rx_bufs = qemu_get_be32(f);
 545
 546     if (version_id >= 3)
 547         n->status = qemu_get_be16(f);
 548
 549     if (version_id >= 4) {
 550         n->promisc = qemu_get_be32(f);
 551         n->allmulti = qemu_get_be32(f);
 552     }
 553
 554     if (version_id >= 5) {
 555         n->mac_table.in_use = qemu_get_be32(f);
 556         /* MAC_TABLE_ENTRIES may be different from the saved image */
 557         if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
 558             qemu_get_buffer(f, n->mac_table.macs,
 559                             n->mac_table.in_use * ETH_ALEN);
 560         } else if (n->mac_table.in_use) {
 561             qemu_fseek(f, n->mac_table.in_use * ETH_ALEN, SEEK_CUR);
 562             n->promisc = 1;
 563             n->mac_table.in_use = 0;
 564         }
 565     }
 566
 567     if (version_id >= 6)
 568         qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
 569
 570     if (n->tx_timer_active) {
 571         qemu_mod_timer(n->tx_timer,
 572                        qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
 573     }
 574
 575     return 0;
 576 }
 577
 578 PCIDevice *virtio_net_init(PCIBus *bus, NICInfo *nd, int devfn)
 579 {
 580     VirtIONet *n;
 581     static int virtio_net_id;
 582
 583     n = (VirtIONet *)virtio_init_pci(bus, "virtio-net",
 584                                      PCI_VENDOR_ID_REDHAT_QUMRANET,
 585                                      PCI_DEVICE_ID_VIRTIO_NET,
 586                                      PCI_VENDOR_ID_REDHAT_QUMRANET,
 587                                      VIRTIO_ID_NET,
 588                                      PCI_CLASS_NETWORK_ETHERNET, 0x00,
 589                                      sizeof(struct virtio_net_config),
 590                                      sizeof(VirtIONet));
 591     if (!n)
 592         return NULL;
 593
 594     n->vdev.get_config = virtio_net_get_config;
 595     n->vdev.set_config = virtio_net_set_config;
 596     n->vdev.get_features = virtio_net_get_features;
 597     n->vdev.set_features = virtio_net_set_features;
 598     n->vdev.bad_features = virtio_net_bad_features;
 599     n->vdev.reset = virtio_net_reset;
 600     n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
 601     n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);
 602     n->ctrl_vq = virtio_add_queue(&n->vdev, 16, virtio_net_handle_ctrl);
 603     memcpy(n->mac, nd->macaddr, ETH_ALEN);
 604     n->status = VIRTIO_NET_S_LINK_UP;
 605     n->vc = qemu_new_vlan_client(nd->vlan, nd->model, nd->name,
 606                                  virtio_net_receive, virtio_net_can_receive, n);
 607     n->vc->link_status_changed = virtio_net_set_link_status;
 608
 609     qemu_format_nic_info_str(n->vc, n->mac);
 610
 611     n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);
 612     n->tx_timer_active = 0;
 613     n->mergeable_rx_bufs = 0;
 614     n->promisc = 1; /* for compatibility */
 615
 616     n->mac_table.macs = qemu_mallocz(MAC_TABLE_ENTRIES * ETH_ALEN);
 617
 618     n->vlans = qemu_mallocz(MAX_VLAN >> 3);
 619
 620     register_savevm("virtio-net", virtio_net_id++, VIRTIO_NET_VM_VERSION,
 621                     virtio_net_save, virtio_net_load, n);
 622     return (PCIDevice *)n;
 623 }