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    10
  20
  21 #define MAC_TABLE_ENTRIES    64
  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     uint32_t has_vnet_hdr;
  36     struct {
  37         VirtQueueElement elem;
  38         ssize_t len;
  39     } async_tx;
  40     int mergeable_rx_bufs;
  41     uint8_t promisc;
  42     uint8_t allmulti;
  43     uint8_t alluni;
  44     uint8_t nomulti;
  45     uint8_t nouni;
  46     uint8_t nobcast;
  47     struct {
  48         int in_use;
  49         int first_multi;
  50         uint8_t multi_overflow;
  51         uint8_t uni_overflow;
  52         uint8_t *macs;
  53     } mac_table;
  54     uint32_t *vlans;
  55 } VirtIONet;
  56
  57 /* TODO
  58  * - we could suppress RX interrupt if we were so inclined.
  59  */
  60
  61 static VirtIONet *to_virtio_net(VirtIODevice *vdev)
  62 {
  63     return (VirtIONet *)vdev;
  64 }
  65
  66 static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
  67 {
  68     VirtIONet *n = to_virtio_net(vdev);
  69     struct virtio_net_config netcfg;
  70
  71     netcfg.status = n->status;
  72     memcpy(netcfg.mac, n->mac, ETH_ALEN);
  73     memcpy(config, &netcfg, sizeof(netcfg));
  74 }
  75
  76 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
  77 {
  78     VirtIONet *n = to_virtio_net(vdev);
  79     struct virtio_net_config netcfg;
  80
  81     memcpy(&netcfg, config, sizeof(netcfg));
  82
  83     if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
  84         memcpy(n->mac, netcfg.mac, ETH_ALEN);
  85         qemu_format_nic_info_str(n->vc, n->mac);
  86     }
  87 }
  88
  89 static void virtio_net_set_link_status(VLANClientState *vc)
  90 {
  91     VirtIONet *n = vc->opaque;
  92     uint16_t old_status = n->status;
  93
  94     if (vc->link_down)
  95         n->status &= ~VIRTIO_NET_S_LINK_UP;
  96     else
  97         n->status |= VIRTIO_NET_S_LINK_UP;
  98
  99     if (n->status != old_status)
 100         virtio_notify_config(&n->vdev);
 101 }
 102
 103 static void virtio_net_reset(VirtIODevice *vdev)
 104 {
 105     VirtIONet *n = to_virtio_net(vdev);
 106
 107     /* Reset back to compatibility mode */
 108     n->promisc = 1;
 109     n->allmulti = 0;
 110     n->alluni = 0;
 111     n->nomulti = 0;
 112     n->nouni = 0;
 113     n->nobcast = 0;
 114
 115     /* Flush any MAC and VLAN filter table state */
 116     n->mac_table.in_use = 0;
 117     n->mac_table.first_multi = 0;
 118     n->mac_table.multi_overflow = 0;
 119     n->mac_table.uni_overflow = 0;
 120     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
 121     memset(n->vlans, 0, MAX_VLAN >> 3);
 122 }
 123
 124 static int peer_has_vnet_hdr(VirtIONet *n)
 125 {
 126     if (!n->vc->peer)
 127         return 0;
 128
 129     if (n->vc->peer->type != NET_CLIENT_TYPE_TAP)
 130         return 0;
 131
 132     n->has_vnet_hdr = tap_has_vnet_hdr(n->vc->peer);
 133
 134     return n->has_vnet_hdr;
 135 }
 136
 137 static uint32_t virtio_net_get_features(VirtIODevice *vdev)
 138 {
 139     VirtIONet *n = to_virtio_net(vdev);
 140     uint32_t features = (1 << VIRTIO_NET_F_MAC) |
 141                         (1 << VIRTIO_NET_F_MRG_RXBUF) |
 142                         (1 << VIRTIO_NET_F_STATUS) |
 143                         (1 << VIRTIO_NET_F_CTRL_VQ) |
 144                         (1 << VIRTIO_NET_F_CTRL_RX) |
 145                         (1 << VIRTIO_NET_F_CTRL_VLAN) |
 146                         (1 << VIRTIO_NET_F_CTRL_RX_EXTRA);
 147
 148     if (peer_has_vnet_hdr(n)) {
 149         tap_using_vnet_hdr(n->vc->peer, 1);
 150
 151         features |= (1 << VIRTIO_NET_F_CSUM);
 152         features |= (1 << VIRTIO_NET_F_HOST_TSO4);
 153         features |= (1 << VIRTIO_NET_F_HOST_TSO6);
 154         features |= (1 << VIRTIO_NET_F_HOST_ECN);
 155
 156         features |= (1 << VIRTIO_NET_F_GUEST_CSUM);
 157         features |= (1 << VIRTIO_NET_F_GUEST_TSO4);
 158         features |= (1 << VIRTIO_NET_F_GUEST_TSO6);
 159         features |= (1 << VIRTIO_NET_F_GUEST_ECN);
 160     }
 161
 162     return features;
 163 }
 164
 165 static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
 166 {
 167     uint32_t features = 0;
 168
 169     /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
 170      * but also these: */
 171     features |= (1 << VIRTIO_NET_F_MAC);
 172     features |= (1 << VIRTIO_NET_F_GUEST_CSUM);
 173     features |= (1 << VIRTIO_NET_F_GUEST_TSO4);
 174     features |= (1 << VIRTIO_NET_F_GUEST_TSO6);
 175     features |= (1 << VIRTIO_NET_F_GUEST_ECN);
 176
 177     return features & virtio_net_get_features(vdev);
 178 }
 179
 180 static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
 181 {
 182     VirtIONet *n = to_virtio_net(vdev);
 183
 184     n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
 185
 186     if (n->has_vnet_hdr) {
 187         tap_set_offload(n->vc->peer,
 188                         (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
 189                         (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
 190                         (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
 191                         (features >> VIRTIO_NET_F_GUEST_ECN)  & 1);
 192     }
 193 }
 194
 195 static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
 196                                      VirtQueueElement *elem)
 197 {
 198     uint8_t on;
 199
 200     if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {
 201         fprintf(stderr, "virtio-net ctrl invalid rx mode command\n");
 202         exit(1);
 203     }
 204
 205     on = ldub_p(elem->out_sg[1].iov_base);
 206
 207     if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)
 208         n->promisc = on;
 209     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
 210         n->allmulti = on;
 211     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLUNI)
 212         n->alluni = on;
 213     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOMULTI)
 214         n->nomulti = on;
 215     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOUNI)
 216         n->nouni = on;
 217     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOBCAST)
 218         n->nobcast = on;
 219     else
 220         return VIRTIO_NET_ERR;
 221
 222     return VIRTIO_NET_OK;
 223 }
 224
 225 static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
 226                                  VirtQueueElement *elem)
 227 {
 228     struct virtio_net_ctrl_mac mac_data;
 229
 230     if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET || elem->out_num != 3 ||
 231         elem->out_sg[1].iov_len < sizeof(mac_data) ||
 232         elem->out_sg[2].iov_len < sizeof(mac_data))
 233         return VIRTIO_NET_ERR;
 234
 235     n->mac_table.in_use = 0;
 236     n->mac_table.first_multi = 0;
 237     n->mac_table.uni_overflow = 0;
 238     n->mac_table.multi_overflow = 0;
 239     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
 240
 241     mac_data.entries = ldl_le_p(elem->out_sg[1].iov_base);
 242
 243     if (sizeof(mac_data.entries) +
 244         (mac_data.entries * ETH_ALEN) > elem->out_sg[1].iov_len)
 245         return VIRTIO_NET_ERR;
 246
 247     if (mac_data.entries <= MAC_TABLE_ENTRIES) {
 248         memcpy(n->mac_table.macs, elem->out_sg[1].iov_base + sizeof(mac_data),
 249                mac_data.entries * ETH_ALEN);
 250         n->mac_table.in_use += mac_data.entries;
 251     } else {
 252         n->mac_table.uni_overflow = 1;
 253     }
 254
 255     n->mac_table.first_multi = n->mac_table.in_use;
 256
 257     mac_data.entries = ldl_le_p(elem->out_sg[2].iov_base);
 258
 259     if (sizeof(mac_data.entries) +
 260         (mac_data.entries * ETH_ALEN) > elem->out_sg[2].iov_len)
 261         return VIRTIO_NET_ERR;
 262
 263     if (mac_data.entries) {
 264         if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
 265             memcpy(n->mac_table.macs + (n->mac_table.in_use * ETH_ALEN),
 266                    elem->out_sg[2].iov_base + sizeof(mac_data),
 267                    mac_data.entries * ETH_ALEN);
 268             n->mac_table.in_use += mac_data.entries;
 269         } else {
 270             n->mac_table.multi_overflow = 1;
 271         }
 272     }
 273
 274     return VIRTIO_NET_OK;
 275 }
 276
 277 static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
 278                                         VirtQueueElement *elem)
 279 {
 280     uint16_t vid;
 281
 282     if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(vid)) {
 283         fprintf(stderr, "virtio-net ctrl invalid vlan command\n");
 284         return VIRTIO_NET_ERR;
 285     }
 286
 287     vid = lduw_le_p(elem->out_sg[1].iov_base);
 288
 289     if (vid >= MAX_VLAN)
 290         return VIRTIO_NET_ERR;
 291
 292     if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
 293         n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
 294     else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
 295         n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
 296     else
 297         return VIRTIO_NET_ERR;
 298
 299     return VIRTIO_NET_OK;
 300 }
 301
 302 static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 303 {
 304     VirtIONet *n = to_virtio_net(vdev);
 305     struct virtio_net_ctrl_hdr ctrl;
 306     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
 307     VirtQueueElement elem;
 308
 309     while (virtqueue_pop(vq, &elem)) {
 310         if ((elem.in_num < 1) || (elem.out_num < 1)) {
 311             fprintf(stderr, "virtio-net ctrl missing headers\n");
 312             exit(1);
 313         }
 314
 315         if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
 316             elem.in_sg[elem.in_num - 1].iov_len < sizeof(status)) {
 317             fprintf(stderr, "virtio-net ctrl header not in correct element\n");
 318             exit(1);
 319         }
 320
 321         ctrl.class = ldub_p(elem.out_sg[0].iov_base);
 322         ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
 323
 324         if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)
 325             status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);
 326         else if (ctrl.class == VIRTIO_NET_CTRL_MAC)
 327             status = virtio_net_handle_mac(n, ctrl.cmd, &elem);
 328         else if (ctrl.class == VIRTIO_NET_CTRL_VLAN)
 329             status = virtio_net_handle_vlan_table(n, ctrl.cmd, &elem);
 330
 331         stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
 332
 333         virtqueue_push(vq, &elem, sizeof(status));
 334         virtio_notify(vdev, vq);
 335     }
 336 }
 337
 338 /* RX */
 339
 340 static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
 341 {
 342     VirtIONet *n = to_virtio_net(vdev);
 343
 344     qemu_flush_queued_packets(n->vc);
 345
 346     /* We now have RX buffers, signal to the IO thread to break out of the
 347      * select to re-poll the tap file descriptor */
 348     qemu_notify_event();
 349 }
 350
 351 static int do_virtio_net_can_receive(VirtIONet *n, int bufsize)
 352 {
 353     if (!virtio_queue_ready(n->rx_vq) ||
 354         !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 355         return 0;
 356
 357     if (virtio_queue_empty(n->rx_vq) ||
 358         (n->mergeable_rx_bufs &&
 359          !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
 360         virtio_queue_set_notification(n->rx_vq, 1);
 361         return 0;
 362     }
 363
 364     virtio_queue_set_notification(n->rx_vq, 0);
 365     return 1;
 366 }
 367
 368 static int virtio_net_can_receive(VLANClientState *vc)
 369 {
 370     VirtIONet *n = vc->opaque;
 371
 372     return do_virtio_net_can_receive(n, VIRTIO_NET_MAX_BUFSIZE);
 373 }
 374
 375 /* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
 376  * it never finds out that the packets don't have valid checksums.  This
 377  * causes dhclient to get upset.  Fedora's carried a patch for ages to
 378  * fix this with Xen but it hasn't appeared in an upstream release of
 379  * dhclient yet.
 380  *
 381  * To avoid breaking existing guests, we catch udp packets and add
 382  * checksums.  This is terrible but it's better than hacking the guest
 383  * kernels.
 384  *
 385  * N.B. if we introduce a zero-copy API, this operation is no longer free so
 386  * we should provide a mechanism to disable it to avoid polluting the host
 387  * cache.
 388  */
 389 static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
 390                                         const uint8_t *buf, size_t size)
 391 {
 392     if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
 393         (size > 27 && size < 1500) && /* normal sized MTU */
 394         (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
 395         (buf[23] == 17) && /* ip.protocol == UDP */
 396         (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
 397         /* FIXME this cast is evil */
 398         net_checksum_calculate((uint8_t *)buf, size);
 399         hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
 400     }
 401 }
 402
 403 static int iov_fill(struct iovec *iov, int iovcnt, const void *buf, int count)
 404 {
 405     int offset, i;
 406
 407     offset = i = 0;
 408     while (offset < count && i < iovcnt) {
 409         int len = MIN(iov[i].iov_len, count - offset);
 410         memcpy(iov[i].iov_base, buf + offset, len);
 411         offset += len;
 412         i++;
 413     }
 414
 415     return offset;
 416 }
 417
 418 static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
 419                           const void *buf, size_t size, size_t hdr_len)
 420 {
 421     struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)iov[0].iov_base;
 422     int offset = 0;
 423
 424     hdr->flags = 0;
 425     hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
 426
 427     if (n->has_vnet_hdr) {
 428         memcpy(hdr, buf, sizeof(*hdr));
 429         offset = sizeof(*hdr);
 430         work_around_broken_dhclient(hdr, buf + offset, size - offset);
 431     }
 432
 433     /* We only ever receive a struct virtio_net_hdr from the tapfd,
 434      * but we may be passing along a larger header to the guest.
 435      */
 436     iov[0].iov_base += hdr_len;
 437     iov[0].iov_len  -= hdr_len;
 438
 439     return offset;
 440 }
 441
 442 static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
 443 {
 444     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 445     static const uint8_t vlan[] = {0x81, 0x00};
 446     uint8_t *ptr = (uint8_t *)buf;
 447     int i;
 448
 449     if (n->promisc)
 450         return 1;
 451
 452     if (n->has_vnet_hdr) {
 453         ptr += sizeof(struct virtio_net_hdr);
 454     }
 455
 456     if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
 457         int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
 458         if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
 459             return 0;
 460     }
 461
 462     if (ptr[0] & 1) { // multicast
 463         if (!memcmp(ptr, bcast, sizeof(bcast))) {
 464             return !n->nobcast;
 465         } else if (n->nomulti) {
 466             return 0;
 467         } else if (n->allmulti || n->mac_table.multi_overflow) {
 468             return 1;
 469         }
 470
 471         for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
 472             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
 473                 return 1;
 474             }
 475         }
 476     } else { // unicast
 477         if (n->nouni) {
 478             return 0;
 479         } else if (n->alluni || n->mac_table.uni_overflow) {
 480             return 1;
 481         } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
 482             return 1;
 483         }
 484
 485         for (i = 0; i < n->mac_table.first_multi; i++) {
 486             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
 487                 return 1;
 488             }
 489         }
 490     }
 491
 492     return 0;
 493 }
 494
 495 static ssize_t virtio_net_receive(VLANClientState *vc, const uint8_t *buf, size_t size)
 496 {
 497     VirtIONet *n = vc->opaque;
 498     struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
 499     size_t hdr_len, offset, i;
 500
 501     if (!do_virtio_net_can_receive(n, size))
 502         return 0;
 503
 504     if (!receive_filter(n, buf, size))
 505         return size;
 506
 507     /* hdr_len refers to the header we supply to the guest */
 508     hdr_len = n->mergeable_rx_bufs ?
 509         sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
 510
 511     offset = i = 0;
 512
 513     while (offset < size) {
 514         VirtQueueElement elem;
 515         int len, total;
 516         struct iovec sg[VIRTQUEUE_MAX_SIZE];
 517
 518         len = total = 0;
 519
 520         if ((i != 0 && !n->mergeable_rx_bufs) ||
 521             virtqueue_pop(n->rx_vq, &elem) == 0) {
 522             if (i == 0)
 523                 return -1;
 524             fprintf(stderr, "virtio-net truncating packet\n");
 525             exit(1);
 526         }
 527
 528         if (elem.in_num < 1) {
 529             fprintf(stderr, "virtio-net receive queue contains no in buffers\n");
 530             exit(1);
 531         }
 532
 533         if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != hdr_len) {
 534             fprintf(stderr, "virtio-net header not in first element\n");
 535             exit(1);
 536         }
 537
 538         memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num);
 539
 540         if (i == 0) {
 541             if (n->mergeable_rx_bufs)
 542                 mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base;
 543
 544             offset += receive_header(n, sg, elem.in_num,
 545                                      buf + offset, size - offset, hdr_len);
 546             total += hdr_len;
 547         }
 548
 549         /* copy in packet.  ugh */
 550         len = iov_fill(sg, elem.in_num,
 551                        buf + offset, size - offset);
 552         total += len;
 553
 554         /* signal other side */
 555         virtqueue_fill(n->rx_vq, &elem, total, i++);
 556
 557         offset += len;
 558     }
 559
 560     if (mhdr)
 561         mhdr->num_buffers = i;
 562
 563     virtqueue_flush(n->rx_vq, i);
 564     virtio_notify(&n->vdev, n->rx_vq);
 565
 566     return size;
 567 }
 568
 569 static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
 570
 571 static void virtio_net_tx_complete(VLANClientState *vc, ssize_t len)
 572 {
 573     VirtIONet *n = vc->opaque;
 574
 575     virtqueue_push(n->tx_vq, &n->async_tx.elem, n->async_tx.len);
 576     virtio_notify(&n->vdev, n->tx_vq);
 577
 578     n->async_tx.elem.out_num = n->async_tx.len = 0;
 579
 580     virtio_queue_set_notification(n->tx_vq, 1);
 581     virtio_net_flush_tx(n, n->tx_vq);
 582 }
 583
 584 /* TX */
 585 static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
 586 {
 587     VirtQueueElement elem;
 588
 589     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 590         return;
 591
 592     if (n->async_tx.elem.out_num) {
 593         virtio_queue_set_notification(n->tx_vq, 0);
 594         return;
 595     }
 596
 597     while (virtqueue_pop(vq, &elem)) {
 598         ssize_t ret, len = 0;
 599         unsigned int out_num = elem.out_num;
 600         struct iovec *out_sg = &elem.out_sg[0];
 601         unsigned hdr_len;
 602
 603         /* hdr_len refers to the header received from the guest */
 604         hdr_len = n->mergeable_rx_bufs ?
 605             sizeof(struct virtio_net_hdr_mrg_rxbuf) :
 606             sizeof(struct virtio_net_hdr);
 607
 608         if (out_num < 1 || out_sg->iov_len != hdr_len) {
 609             fprintf(stderr, "virtio-net header not in first element\n");
 610             exit(1);
 611         }
 612
 613         /* ignore the header if GSO is not supported */
 614         if (!n->has_vnet_hdr) {
 615             out_num--;
 616             out_sg++;
 617             len += hdr_len;
 618         } else if (n->mergeable_rx_bufs) {
 619             /* tapfd expects a struct virtio_net_hdr */
 620             hdr_len -= sizeof(struct virtio_net_hdr);
 621             out_sg->iov_len -= hdr_len;
 622             len += hdr_len;
 623         }
 624
 625         ret = qemu_sendv_packet_async(n->vc, out_sg, out_num,
 626                                       virtio_net_tx_complete);
 627         if (ret == 0) {
 628             virtio_queue_set_notification(n->tx_vq, 0);
 629             n->async_tx.elem = elem;
 630             n->async_tx.len  = len;
 631             return;
 632         }
 633
 634         len += ret;
 635
 636         virtqueue_push(vq, &elem, len);
 637         virtio_notify(&n->vdev, vq);
 638     }
 639 }
 640
 641 static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq)
 642 {
 643     VirtIONet *n = to_virtio_net(vdev);
 644
 645     if (n->tx_timer_active) {
 646         virtio_queue_set_notification(vq, 1);
 647         qemu_del_timer(n->tx_timer);
 648         n->tx_timer_active = 0;
 649         virtio_net_flush_tx(n, vq);
 650     } else {
 651         qemu_mod_timer(n->tx_timer,
 652                        qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
 653         n->tx_timer_active = 1;
 654         virtio_queue_set_notification(vq, 0);
 655     }
 656 }
 657
 658 static void virtio_net_tx_timer(void *opaque)
 659 {
 660     VirtIONet *n = opaque;
 661
 662     n->tx_timer_active = 0;
 663
 664     /* Just in case the driver is not ready on more */
 665     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 666         return;
 667
 668     virtio_queue_set_notification(n->tx_vq, 1);
 669     virtio_net_flush_tx(n, n->tx_vq);
 670 }
 671
 672 static void virtio_net_save(QEMUFile *f, void *opaque)
 673 {
 674     VirtIONet *n = opaque;
 675
 676     virtio_save(&n->vdev, f);
 677
 678     qemu_put_buffer(f, n->mac, ETH_ALEN);
 679     qemu_put_be32(f, n->tx_timer_active);
 680     qemu_put_be32(f, n->mergeable_rx_bufs);
 681     qemu_put_be16(f, n->status);
 682     qemu_put_byte(f, n->promisc);
 683     qemu_put_byte(f, n->allmulti);
 684     qemu_put_be32(f, n->mac_table.in_use);
 685     qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
 686     qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
 687     qemu_put_be32(f, n->has_vnet_hdr);
 688     qemu_put_byte(f, n->mac_table.multi_overflow);
 689     qemu_put_byte(f, n->mac_table.uni_overflow);
 690     qemu_put_byte(f, n->alluni);
 691     qemu_put_byte(f, n->nomulti);
 692     qemu_put_byte(f, n->nouni);
 693     qemu_put_byte(f, n->nobcast);
 694 }
 695
 696 static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
 697 {
 698     VirtIONet *n = opaque;
 699     int i;
 700
 701     if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
 702         return -EINVAL;
 703
 704     virtio_load(&n->vdev, f);
 705
 706     qemu_get_buffer(f, n->mac, ETH_ALEN);
 707     n->tx_timer_active = qemu_get_be32(f);
 708     n->mergeable_rx_bufs = qemu_get_be32(f);
 709
 710     if (version_id >= 3)
 711         n->status = qemu_get_be16(f);
 712
 713     if (version_id >= 4) {
 714         if (version_id < 8) {
 715             n->promisc = qemu_get_be32(f);
 716             n->allmulti = qemu_get_be32(f);
 717         } else {
 718             n->promisc = qemu_get_byte(f);
 719             n->allmulti = qemu_get_byte(f);
 720         }
 721     }
 722
 723     if (version_id >= 5) {
 724         n->mac_table.in_use = qemu_get_be32(f);
 725         /* MAC_TABLE_ENTRIES may be different from the saved image */
 726         if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
 727             qemu_get_buffer(f, n->mac_table.macs,
 728                             n->mac_table.in_use * ETH_ALEN);
 729         } else if (n->mac_table.in_use) {
 730             qemu_fseek(f, n->mac_table.in_use * ETH_ALEN, SEEK_CUR);
 731             n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
 732             n->mac_table.in_use = 0;
 733         }
 734     }
 735
 736     if (version_id >= 6)
 737         qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
 738
 739     if (version_id >= 7) {
 740         if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
 741             qemu_error("virtio-net: saved image requires vnet_hdr=on\n");
 742             return -1;
 743         }
 744
 745         if (n->has_vnet_hdr) {
 746             tap_using_vnet_hdr(n->vc->peer, 1);
 747             tap_set_offload(n->vc->peer,
 748                             (n->vdev.features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
 749                             (n->vdev.features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
 750                             (n->vdev.features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
 751                             (n->vdev.features >> VIRTIO_NET_F_GUEST_ECN)  & 1);
 752         }
 753     }
 754
 755     if (version_id >= 9) {
 756         n->mac_table.multi_overflow = qemu_get_byte(f);
 757         n->mac_table.uni_overflow = qemu_get_byte(f);
 758     }
 759
 760     if (version_id >= 10) {
 761         n->alluni = qemu_get_byte(f);
 762         n->nomulti = qemu_get_byte(f);
 763         n->nouni = qemu_get_byte(f);
 764         n->nobcast = qemu_get_byte(f);
 765     }
 766
 767     /* Find the first multicast entry in the saved MAC filter */
 768     for (i = 0; i < n->mac_table.in_use; i++) {
 769         if (n->mac_table.macs[i * ETH_ALEN] & 1) {
 770             break;
 771         }
 772     }
 773     n->mac_table.first_multi = i;
 774
 775     if (n->tx_timer_active) {
 776         qemu_mod_timer(n->tx_timer,
 777                        qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
 778     }
 779
 780     return 0;
 781 }
 782
 783 static void virtio_net_cleanup(VLANClientState *vc)
 784 {
 785     VirtIONet *n = vc->opaque;
 786
 787     n->vc = NULL;
 788 }
 789
 790 VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf)
 791 {
 792     VirtIONet *n;
 793     static int virtio_net_id;
 794
 795     n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
 796                                         sizeof(struct virtio_net_config),
 797                                         sizeof(VirtIONet));
 798
 799     n->vdev.get_config = virtio_net_get_config;
 800     n->vdev.set_config = virtio_net_set_config;
 801     n->vdev.get_features = virtio_net_get_features;
 802     n->vdev.set_features = virtio_net_set_features;
 803     n->vdev.bad_features = virtio_net_bad_features;
 804     n->vdev.reset = virtio_net_reset;
 805     n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
 806     n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);
 807     n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
 808     qemu_macaddr_default_if_unset(&conf->macaddr);
 809     n->status = VIRTIO_NET_S_LINK_UP;
 810     n->vc = qemu_new_vlan_client(NET_CLIENT_TYPE_NIC, conf->vlan, conf->peer,
 811                                  dev->info->name, dev->id,
 812                                  virtio_net_can_receive,
 813                                  virtio_net_receive, NULL, NULL,
 814                                  virtio_net_cleanup, n);
 815     n->vc->link_status_changed = virtio_net_set_link_status;
 816
 817     qemu_format_nic_info_str(n->vc, conf->macaddr.a);
 818
 819     n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);
 820     n->tx_timer_active = 0;
 821     n->mergeable_rx_bufs = 0;
 822     n->promisc = 1; /* for compatibility */
 823
 824     n->mac_table.macs = qemu_mallocz(MAC_TABLE_ENTRIES * ETH_ALEN);
 825
 826     n->vlans = qemu_mallocz(MAX_VLAN >> 3);
 827
 828     register_savevm("virtio-net", virtio_net_id++, VIRTIO_NET_VM_VERSION,
 829                     virtio_net_save, virtio_net_load, n);
 830
 831     return &n->vdev;
 832 }
 833
 834 void virtio_net_exit(VirtIODevice *vdev)
 835 {
 836     VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
 837
 838     qemu_purge_queued_packets(n->vc);
 839
 840     unregister_savevm("virtio-net", n);
 841
 842     qemu_free(n->mac_table.macs);
 843     qemu_free(n->vlans);
 844
 845     qemu_del_timer(n->tx_timer);
 846     qemu_free_timer(n->tx_timer);
 847
 848     virtio_cleanup(&n->vdev);
 849     qemu_del_vlan_client(n->vc);
 850 }