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 "net/checksum.h"
  17 #include "net/tap.h"
  18 #include "qemu-error.h"
  19 #include "qemu-timer.h"
  20 #include "virtio-net.h"
  21
  22 #define VIRTIO_NET_VM_VERSION    11
  23
  24 #define MAC_TABLE_ENTRIES    64
  25 #define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
  26
  27 typedef struct VirtIONet
  28 {
  29     VirtIODevice vdev;
  30     uint8_t mac[ETH_ALEN];
  31     uint16_t status;
  32     VirtQueue *rx_vq;
  33     VirtQueue *tx_vq;
  34     VirtQueue *ctrl_vq;
  35     NICState *nic;
  36     QEMUTimer *tx_timer;
  37     int tx_timer_active;
  38     uint32_t has_vnet_hdr;
  39     uint8_t has_ufo;
  40     struct {
  41         VirtQueueElement elem;
  42         ssize_t len;
  43     } async_tx;
  44     int mergeable_rx_bufs;
  45     uint8_t promisc;
  46     uint8_t allmulti;
  47     uint8_t alluni;
  48     uint8_t nomulti;
  49     uint8_t nouni;
  50     uint8_t nobcast;
  51     struct {
  52         int in_use;
  53         int first_multi;
  54         uint8_t multi_overflow;
  55         uint8_t uni_overflow;
  56         uint8_t *macs;
  57     } mac_table;
  58     uint32_t *vlans;
  59 } VirtIONet;
  60
  61 /* TODO
  62  * - we could suppress RX interrupt if we were so inclined.
  63  */
  64
  65 static VirtIONet *to_virtio_net(VirtIODevice *vdev)
  66 {
  67     return (VirtIONet *)vdev;
  68 }
  69
  70 static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
  71 {
  72     VirtIONet *n = to_virtio_net(vdev);
  73     struct virtio_net_config netcfg;
  74
  75     netcfg.status = n->status;
  76     memcpy(netcfg.mac, n->mac, ETH_ALEN);
  77     memcpy(config, &netcfg, sizeof(netcfg));
  78 }
  79
  80 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
  81 {
  82     VirtIONet *n = to_virtio_net(vdev);
  83     struct virtio_net_config netcfg;
  84
  85     memcpy(&netcfg, config, sizeof(netcfg));
  86
  87     if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
  88         memcpy(n->mac, netcfg.mac, ETH_ALEN);
  89         qemu_format_nic_info_str(&n->nic->nc, n->mac);
  90     }
  91 }
  92
  93 static void virtio_net_set_link_status(VLANClientState *nc)
  94 {
  95     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
  96     uint16_t old_status = n->status;
  97
  98     if (nc->link_down)
  99         n->status &= ~VIRTIO_NET_S_LINK_UP;
 100     else
 101         n->status |= VIRTIO_NET_S_LINK_UP;
 102
 103     if (n->status != old_status)
 104         virtio_notify_config(&n->vdev);
 105 }
 106
 107 static void virtio_net_reset(VirtIODevice *vdev)
 108 {
 109     VirtIONet *n = to_virtio_net(vdev);
 110
 111     /* Reset back to compatibility mode */
 112     n->promisc = 1;
 113     n->allmulti = 0;
 114     n->alluni = 0;
 115     n->nomulti = 0;
 116     n->nouni = 0;
 117     n->nobcast = 0;
 118
 119     /* Flush any MAC and VLAN filter table state */
 120     n->mac_table.in_use = 0;
 121     n->mac_table.first_multi = 0;
 122     n->mac_table.multi_overflow = 0;
 123     n->mac_table.uni_overflow = 0;
 124     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
 125     memset(n->vlans, 0, MAX_VLAN >> 3);
 126 }
 127
 128 static int peer_has_vnet_hdr(VirtIONet *n)
 129 {
 130     if (!n->nic->nc.peer)
 131         return 0;
 132
 133     if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP)
 134         return 0;
 135
 136     n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
 137
 138     return n->has_vnet_hdr;
 139 }
 140
 141 static int peer_has_ufo(VirtIONet *n)
 142 {
 143     if (!peer_has_vnet_hdr(n))
 144         return 0;
 145
 146     n->has_ufo = tap_has_ufo(n->nic->nc.peer);
 147
 148     return n->has_ufo;
 149 }
 150
 151 static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
 152 {
 153     VirtIONet *n = to_virtio_net(vdev);
 154
 155     features |= (1 << VIRTIO_NET_F_MAC);
 156
 157     if (peer_has_vnet_hdr(n)) {
 158         tap_using_vnet_hdr(n->nic->nc.peer, 1);
 159     } else {
 160         features &= ~(0x1 << VIRTIO_NET_F_CSUM);
 161         features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO4);
 162         features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO6);
 163         features &= ~(0x1 << VIRTIO_NET_F_HOST_ECN);
 164
 165         features &= ~(0x1 << VIRTIO_NET_F_GUEST_CSUM);
 166         features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO4);
 167         features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO6);
 168         features &= ~(0x1 << VIRTIO_NET_F_GUEST_ECN);
 169     }
 170
 171     if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
 172         features &= ~(0x1 << VIRTIO_NET_F_GUEST_UFO);
 173         features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
 174     }
 175
 176     return features;
 177 }
 178
 179 static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
 180 {
 181     uint32_t features = 0;
 182
 183     /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
 184      * but also these: */
 185     features |= (1 << VIRTIO_NET_F_MAC);
 186     features |= (1 << VIRTIO_NET_F_CSUM);
 187     features |= (1 << VIRTIO_NET_F_HOST_TSO4);
 188     features |= (1 << VIRTIO_NET_F_HOST_TSO6);
 189     features |= (1 << VIRTIO_NET_F_HOST_ECN);
 190
 191     return features;
 192 }
 193
 194 static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
 195 {
 196     VirtIONet *n = to_virtio_net(vdev);
 197
 198     n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
 199
 200     if (n->has_vnet_hdr) {
 201         tap_set_offload(n->nic->nc.peer,
 202                         (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
 203                         (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
 204                         (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
 205                         (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
 206                         (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
 207     }
 208 }
 209
 210 static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
 211                                      VirtQueueElement *elem)
 212 {
 213     uint8_t on;
 214
 215     if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {
 216         fprintf(stderr, "virtio-net ctrl invalid rx mode command\n");
 217         exit(1);
 218     }
 219
 220     on = ldub_p(elem->out_sg[1].iov_base);
 221
 222     if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)
 223         n->promisc = on;
 224     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
 225         n->allmulti = on;
 226     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLUNI)
 227         n->alluni = on;
 228     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOMULTI)
 229         n->nomulti = on;
 230     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOUNI)
 231         n->nouni = on;
 232     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOBCAST)
 233         n->nobcast = on;
 234     else
 235         return VIRTIO_NET_ERR;
 236
 237     return VIRTIO_NET_OK;
 238 }
 239
 240 static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
 241                                  VirtQueueElement *elem)
 242 {
 243     struct virtio_net_ctrl_mac mac_data;
 244
 245     if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET || elem->out_num != 3 ||
 246         elem->out_sg[1].iov_len < sizeof(mac_data) ||
 247         elem->out_sg[2].iov_len < sizeof(mac_data))
 248         return VIRTIO_NET_ERR;
 249
 250     n->mac_table.in_use = 0;
 251     n->mac_table.first_multi = 0;
 252     n->mac_table.uni_overflow = 0;
 253     n->mac_table.multi_overflow = 0;
 254     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
 255
 256     mac_data.entries = ldl_le_p(elem->out_sg[1].iov_base);
 257
 258     if (sizeof(mac_data.entries) +
 259         (mac_data.entries * ETH_ALEN) > elem->out_sg[1].iov_len)
 260         return VIRTIO_NET_ERR;
 261
 262     if (mac_data.entries <= MAC_TABLE_ENTRIES) {
 263         memcpy(n->mac_table.macs, elem->out_sg[1].iov_base + sizeof(mac_data),
 264                mac_data.entries * ETH_ALEN);
 265         n->mac_table.in_use += mac_data.entries;
 266     } else {
 267         n->mac_table.uni_overflow = 1;
 268     }
 269
 270     n->mac_table.first_multi = n->mac_table.in_use;
 271
 272     mac_data.entries = ldl_le_p(elem->out_sg[2].iov_base);
 273
 274     if (sizeof(mac_data.entries) +
 275         (mac_data.entries * ETH_ALEN) > elem->out_sg[2].iov_len)
 276         return VIRTIO_NET_ERR;
 277
 278     if (mac_data.entries) {
 279         if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
 280             memcpy(n->mac_table.macs + (n->mac_table.in_use * ETH_ALEN),
 281                    elem->out_sg[2].iov_base + sizeof(mac_data),
 282                    mac_data.entries * ETH_ALEN);
 283             n->mac_table.in_use += mac_data.entries;
 284         } else {
 285             n->mac_table.multi_overflow = 1;
 286         }
 287     }
 288
 289     return VIRTIO_NET_OK;
 290 }
 291
 292 static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
 293                                         VirtQueueElement *elem)
 294 {
 295     uint16_t vid;
 296
 297     if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(vid)) {
 298         fprintf(stderr, "virtio-net ctrl invalid vlan command\n");
 299         return VIRTIO_NET_ERR;
 300     }
 301
 302     vid = lduw_le_p(elem->out_sg[1].iov_base);
 303
 304     if (vid >= MAX_VLAN)
 305         return VIRTIO_NET_ERR;
 306
 307     if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
 308         n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
 309     else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
 310         n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
 311     else
 312         return VIRTIO_NET_ERR;
 313
 314     return VIRTIO_NET_OK;
 315 }
 316
 317 static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 318 {
 319     VirtIONet *n = to_virtio_net(vdev);
 320     struct virtio_net_ctrl_hdr ctrl;
 321     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
 322     VirtQueueElement elem;
 323
 324     while (virtqueue_pop(vq, &elem)) {
 325         if ((elem.in_num < 1) || (elem.out_num < 1)) {
 326             fprintf(stderr, "virtio-net ctrl missing headers\n");
 327             exit(1);
 328         }
 329
 330         if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
 331             elem.in_sg[elem.in_num - 1].iov_len < sizeof(status)) {
 332             fprintf(stderr, "virtio-net ctrl header not in correct element\n");
 333             exit(1);
 334         }
 335
 336         ctrl.class = ldub_p(elem.out_sg[0].iov_base);
 337         ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
 338
 339         if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)
 340             status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);
 341         else if (ctrl.class == VIRTIO_NET_CTRL_MAC)
 342             status = virtio_net_handle_mac(n, ctrl.cmd, &elem);
 343         else if (ctrl.class == VIRTIO_NET_CTRL_VLAN)
 344             status = virtio_net_handle_vlan_table(n, ctrl.cmd, &elem);
 345
 346         stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
 347
 348         virtqueue_push(vq, &elem, sizeof(status));
 349         virtio_notify(vdev, vq);
 350     }
 351 }
 352
 353 /* RX */
 354
 355 static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
 356 {
 357     VirtIONet *n = to_virtio_net(vdev);
 358
 359     qemu_flush_queued_packets(&n->nic->nc);
 360
 361     /* We now have RX buffers, signal to the IO thread to break out of the
 362      * select to re-poll the tap file descriptor */
 363     qemu_notify_event();
 364 }
 365
 366 static int virtio_net_can_receive(VLANClientState *nc)
 367 {
 368     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
 369
 370     if (!virtio_queue_ready(n->rx_vq) ||
 371         !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 372         return 0;
 373
 374     return 1;
 375 }
 376
 377 static int virtio_net_has_buffers(VirtIONet *n, int bufsize)
 378 {
 379     if (virtio_queue_empty(n->rx_vq) ||
 380         (n->mergeable_rx_bufs &&
 381          !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
 382         virtio_queue_set_notification(n->rx_vq, 1);
 383
 384         /* To avoid a race condition where the guest has made some buffers
 385          * available after the above check but before notification was
 386          * enabled, check for available buffers again.
 387          */
 388         if (virtio_queue_empty(n->rx_vq) ||
 389             (n->mergeable_rx_bufs &&
 390              !virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))
 391             return 0;
 392     }
 393
 394     virtio_queue_set_notification(n->rx_vq, 0);
 395     return 1;
 396 }
 397
 398 /* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
 399  * it never finds out that the packets don't have valid checksums.  This
 400  * causes dhclient to get upset.  Fedora's carried a patch for ages to
 401  * fix this with Xen but it hasn't appeared in an upstream release of
 402  * dhclient yet.
 403  *
 404  * To avoid breaking existing guests, we catch udp packets and add
 405  * checksums.  This is terrible but it's better than hacking the guest
 406  * kernels.
 407  *
 408  * N.B. if we introduce a zero-copy API, this operation is no longer free so
 409  * we should provide a mechanism to disable it to avoid polluting the host
 410  * cache.
 411  */
 412 static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
 413                                         const uint8_t *buf, size_t size)
 414 {
 415     if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
 416         (size > 27 && size < 1500) && /* normal sized MTU */
 417         (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
 418         (buf[23] == 17) && /* ip.protocol == UDP */
 419         (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
 420         /* FIXME this cast is evil */
 421         net_checksum_calculate((uint8_t *)buf, size);
 422         hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
 423     }
 424 }
 425
 426 static int iov_fill(struct iovec *iov, int iovcnt, const void *buf, int count)
 427 {
 428     int offset, i;
 429
 430     offset = i = 0;
 431     while (offset < count && i < iovcnt) {
 432         int len = MIN(iov[i].iov_len, count - offset);
 433         memcpy(iov[i].iov_base, buf + offset, len);
 434         offset += len;
 435         i++;
 436     }
 437
 438     return offset;
 439 }
 440
 441 static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
 442                           const void *buf, size_t size, size_t hdr_len)
 443 {
 444     struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)iov[0].iov_base;
 445     int offset = 0;
 446
 447     hdr->flags = 0;
 448     hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
 449
 450     if (n->has_vnet_hdr) {
 451         memcpy(hdr, buf, sizeof(*hdr));
 452         offset = sizeof(*hdr);
 453         work_around_broken_dhclient(hdr, buf + offset, size - offset);
 454     }
 455
 456     /* We only ever receive a struct virtio_net_hdr from the tapfd,
 457      * but we may be passing along a larger header to the guest.
 458      */
 459     iov[0].iov_base += hdr_len;
 460     iov[0].iov_len  -= hdr_len;
 461
 462     return offset;
 463 }
 464
 465 static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
 466 {
 467     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 468     static const uint8_t vlan[] = {0x81, 0x00};
 469     uint8_t *ptr = (uint8_t *)buf;
 470     int i;
 471
 472     if (n->promisc)
 473         return 1;
 474
 475     if (n->has_vnet_hdr) {
 476         ptr += sizeof(struct virtio_net_hdr);
 477     }
 478
 479     if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
 480         int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
 481         if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
 482             return 0;
 483     }
 484
 485     if (ptr[0] & 1) { // multicast
 486         if (!memcmp(ptr, bcast, sizeof(bcast))) {
 487             return !n->nobcast;
 488         } else if (n->nomulti) {
 489             return 0;
 490         } else if (n->allmulti || n->mac_table.multi_overflow) {
 491             return 1;
 492         }
 493
 494         for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
 495             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
 496                 return 1;
 497             }
 498         }
 499     } else { // unicast
 500         if (n->nouni) {
 501             return 0;
 502         } else if (n->alluni || n->mac_table.uni_overflow) {
 503             return 1;
 504         } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
 505             return 1;
 506         }
 507
 508         for (i = 0; i < n->mac_table.first_multi; i++) {
 509             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
 510                 return 1;
 511             }
 512         }
 513     }
 514
 515     return 0;
 516 }
 517
 518 static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
 519 {
 520     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
 521     struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
 522     size_t hdr_len, offset, i;
 523
 524     if (!virtio_net_can_receive(&n->nic->nc))
 525         return -1;
 526
 527     if (!virtio_net_has_buffers(n, size))
 528         return 0;
 529
 530     if (!receive_filter(n, buf, size))
 531         return size;
 532
 533     /* hdr_len refers to the header we supply to the guest */
 534     hdr_len = n->mergeable_rx_bufs ?
 535         sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
 536
 537     offset = i = 0;
 538
 539     while (offset < size) {
 540         VirtQueueElement elem;
 541         int len, total;
 542         struct iovec sg[VIRTQUEUE_MAX_SIZE];
 543
 544         total = 0;
 545
 546         if ((i != 0 && !n->mergeable_rx_bufs) ||
 547             virtqueue_pop(n->rx_vq, &elem) == 0) {
 548             if (i == 0)
 549                 return -1;
 550             fprintf(stderr, "virtio-net truncating packet\n");
 551             exit(1);
 552         }
 553
 554         if (elem.in_num < 1) {
 555             fprintf(stderr, "virtio-net receive queue contains no in buffers\n");
 556             exit(1);
 557         }
 558
 559         if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != hdr_len) {
 560             fprintf(stderr, "virtio-net header not in first element\n");
 561             exit(1);
 562         }
 563
 564         memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num);
 565
 566         if (i == 0) {
 567             if (n->mergeable_rx_bufs)
 568                 mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base;
 569
 570             offset += receive_header(n, sg, elem.in_num,
 571                                      buf + offset, size - offset, hdr_len);
 572             total += hdr_len;
 573         }
 574
 575         /* copy in packet.  ugh */
 576         len = iov_fill(sg, elem.in_num,
 577                        buf + offset, size - offset);
 578         total += len;
 579
 580         /* signal other side */
 581         virtqueue_fill(n->rx_vq, &elem, total, i++);
 582
 583         offset += len;
 584     }
 585
 586     if (mhdr)
 587         mhdr->num_buffers = i;
 588
 589     virtqueue_flush(n->rx_vq, i);
 590     virtio_notify(&n->vdev, n->rx_vq);
 591
 592     return size;
 593 }
 594
 595 static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
 596
 597 static void virtio_net_tx_complete(VLANClientState *nc, ssize_t len)
 598 {
 599     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
 600
 601     virtqueue_push(n->tx_vq, &n->async_tx.elem, n->async_tx.len);
 602     virtio_notify(&n->vdev, n->tx_vq);
 603
 604     n->async_tx.elem.out_num = n->async_tx.len = 0;
 605
 606     virtio_queue_set_notification(n->tx_vq, 1);
 607     virtio_net_flush_tx(n, n->tx_vq);
 608 }
 609
 610 /* TX */
 611 static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
 612 {
 613     VirtQueueElement elem;
 614
 615     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 616         return;
 617
 618     if (n->async_tx.elem.out_num) {
 619         virtio_queue_set_notification(n->tx_vq, 0);
 620         return;
 621     }
 622
 623     while (virtqueue_pop(vq, &elem)) {
 624         ssize_t ret, len = 0;
 625         unsigned int out_num = elem.out_num;
 626         struct iovec *out_sg = &elem.out_sg[0];
 627         unsigned hdr_len;
 628
 629         /* hdr_len refers to the header received from the guest */
 630         hdr_len = n->mergeable_rx_bufs ?
 631             sizeof(struct virtio_net_hdr_mrg_rxbuf) :
 632             sizeof(struct virtio_net_hdr);
 633
 634         if (out_num < 1 || out_sg->iov_len != hdr_len) {
 635             fprintf(stderr, "virtio-net header not in first element\n");
 636             exit(1);
 637         }
 638
 639         /* ignore the header if GSO is not supported */
 640         if (!n->has_vnet_hdr) {
 641             out_num--;
 642             out_sg++;
 643             len += hdr_len;
 644         } else if (n->mergeable_rx_bufs) {
 645             /* tapfd expects a struct virtio_net_hdr */
 646             hdr_len -= sizeof(struct virtio_net_hdr);
 647             out_sg->iov_len -= hdr_len;
 648             len += hdr_len;
 649         }
 650
 651         ret = qemu_sendv_packet_async(&n->nic->nc, out_sg, out_num,
 652                                       virtio_net_tx_complete);
 653         if (ret == 0) {
 654             virtio_queue_set_notification(n->tx_vq, 0);
 655             n->async_tx.elem = elem;
 656             n->async_tx.len  = len;
 657             return;
 658         }
 659
 660         len += ret;
 661
 662         virtqueue_push(vq, &elem, len);
 663         virtio_notify(&n->vdev, vq);
 664     }
 665 }
 666
 667 static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq)
 668 {
 669     VirtIONet *n = to_virtio_net(vdev);
 670
 671     if (n->tx_timer_active) {
 672         virtio_queue_set_notification(vq, 1);
 673         qemu_del_timer(n->tx_timer);
 674         n->tx_timer_active = 0;
 675         virtio_net_flush_tx(n, vq);
 676     } else {
 677         qemu_mod_timer(n->tx_timer,
 678                        qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
 679         n->tx_timer_active = 1;
 680         virtio_queue_set_notification(vq, 0);
 681     }
 682 }
 683
 684 static void virtio_net_tx_timer(void *opaque)
 685 {
 686     VirtIONet *n = opaque;
 687
 688     n->tx_timer_active = 0;
 689
 690     /* Just in case the driver is not ready on more */
 691     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 692         return;
 693
 694     virtio_queue_set_notification(n->tx_vq, 1);
 695     virtio_net_flush_tx(n, n->tx_vq);
 696 }
 697
 698 static void virtio_net_save(QEMUFile *f, void *opaque)
 699 {
 700     VirtIONet *n = opaque;
 701
 702     virtio_save(&n->vdev, f);
 703
 704     qemu_put_buffer(f, n->mac, ETH_ALEN);
 705     qemu_put_be32(f, n->tx_timer_active);
 706     qemu_put_be32(f, n->mergeable_rx_bufs);
 707     qemu_put_be16(f, n->status);
 708     qemu_put_byte(f, n->promisc);
 709     qemu_put_byte(f, n->allmulti);
 710     qemu_put_be32(f, n->mac_table.in_use);
 711     qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
 712     qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
 713     qemu_put_be32(f, n->has_vnet_hdr);
 714     qemu_put_byte(f, n->mac_table.multi_overflow);
 715     qemu_put_byte(f, n->mac_table.uni_overflow);
 716     qemu_put_byte(f, n->alluni);
 717     qemu_put_byte(f, n->nomulti);
 718     qemu_put_byte(f, n->nouni);
 719     qemu_put_byte(f, n->nobcast);
 720     qemu_put_byte(f, n->has_ufo);
 721 }
 722
 723 static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
 724 {
 725     VirtIONet *n = opaque;
 726     int i;
 727
 728     if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
 729         return -EINVAL;
 730
 731     virtio_load(&n->vdev, f);
 732
 733     qemu_get_buffer(f, n->mac, ETH_ALEN);
 734     n->tx_timer_active = qemu_get_be32(f);
 735     n->mergeable_rx_bufs = qemu_get_be32(f);
 736
 737     if (version_id >= 3)
 738         n->status = qemu_get_be16(f);
 739
 740     if (version_id >= 4) {
 741         if (version_id < 8) {
 742             n->promisc = qemu_get_be32(f);
 743             n->allmulti = qemu_get_be32(f);
 744         } else {
 745             n->promisc = qemu_get_byte(f);
 746             n->allmulti = qemu_get_byte(f);
 747         }
 748     }
 749
 750     if (version_id >= 5) {
 751         n->mac_table.in_use = qemu_get_be32(f);
 752         /* MAC_TABLE_ENTRIES may be different from the saved image */
 753         if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
 754             qemu_get_buffer(f, n->mac_table.macs,
 755                             n->mac_table.in_use * ETH_ALEN);
 756         } else if (n->mac_table.in_use) {
 757             qemu_fseek(f, n->mac_table.in_use * ETH_ALEN, SEEK_CUR);
 758             n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
 759             n->mac_table.in_use = 0;
 760         }
 761     }
 762
 763     if (version_id >= 6)
 764         qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
 765
 766     if (version_id >= 7) {
 767         if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
 768             error_report("virtio-net: saved image requires vnet_hdr=on");
 769             return -1;
 770         }
 771
 772         if (n->has_vnet_hdr) {
 773             tap_using_vnet_hdr(n->nic->nc.peer, 1);
 774             tap_set_offload(n->nic->nc.peer,
 775                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
 776                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
 777                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
 778                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
 779                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
 780         }
 781     }
 782
 783     if (version_id >= 9) {
 784         n->mac_table.multi_overflow = qemu_get_byte(f);
 785         n->mac_table.uni_overflow = qemu_get_byte(f);
 786     }
 787
 788     if (version_id >= 10) {
 789         n->alluni = qemu_get_byte(f);
 790         n->nomulti = qemu_get_byte(f);
 791         n->nouni = qemu_get_byte(f);
 792         n->nobcast = qemu_get_byte(f);
 793     }
 794
 795     if (version_id >= 11) {
 796         if (qemu_get_byte(f) && !peer_has_ufo(n)) {
 797             error_report("virtio-net: saved image requires TUN_F_UFO support");
 798             return -1;
 799         }
 800     }
 801
 802     /* Find the first multicast entry in the saved MAC filter */
 803     for (i = 0; i < n->mac_table.in_use; i++) {
 804         if (n->mac_table.macs[i * ETH_ALEN] & 1) {
 805             break;
 806         }
 807     }
 808     n->mac_table.first_multi = i;
 809
 810     if (n->tx_timer_active) {
 811         qemu_mod_timer(n->tx_timer,
 812                        qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
 813     }
 814
 815     return 0;
 816 }
 817
 818 static void virtio_net_cleanup(VLANClientState *nc)
 819 {
 820     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
 821
 822     n->nic = NULL;
 823 }
 824
 825 static NetClientInfo net_virtio_info = {
 826     .type = NET_CLIENT_TYPE_NIC,
 827     .size = sizeof(NICState),
 828     .can_receive = virtio_net_can_receive,
 829     .receive = virtio_net_receive,
 830         .cleanup = virtio_net_cleanup,
 831     .link_status_changed = virtio_net_set_link_status,
 832 };
 833
 834 VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf)
 835 {
 836     VirtIONet *n;
 837     static int virtio_net_id;
 838
 839     n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
 840                                         sizeof(struct virtio_net_config),
 841                                         sizeof(VirtIONet));
 842
 843     n->vdev.get_config = virtio_net_get_config;
 844     n->vdev.set_config = virtio_net_set_config;
 845     n->vdev.get_features = virtio_net_get_features;
 846     n->vdev.set_features = virtio_net_set_features;
 847     n->vdev.bad_features = virtio_net_bad_features;
 848     n->vdev.reset = virtio_net_reset;
 849     n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
 850     n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);
 851     n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
 852     qemu_macaddr_default_if_unset(&conf->macaddr);
 853     memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
 854     n->status = VIRTIO_NET_S_LINK_UP;
 855
 856     n->nic = qemu_new_nic(&net_virtio_info, conf, dev->info->name, dev->id, n);
 857
 858     qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
 859
 860     n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);
 861     n->tx_timer_active = 0;
 862     n->mergeable_rx_bufs = 0;
 863     n->promisc = 1; /* for compatibility */
 864
 865     n->mac_table.macs = qemu_mallocz(MAC_TABLE_ENTRIES * ETH_ALEN);
 866
 867     n->vlans = qemu_mallocz(MAX_VLAN >> 3);
 868
 869     register_savevm("virtio-net", virtio_net_id++, VIRTIO_NET_VM_VERSION,
 870                     virtio_net_save, virtio_net_load, n);
 871
 872     return &n->vdev;
 873 }
 874
 875 void virtio_net_exit(VirtIODevice *vdev)
 876 {
 877     VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
 878
 879     qemu_purge_queued_packets(&n->nic->nc);
 880
 881     unregister_savevm("virtio-net", n);
 882
 883     qemu_free(n->mac_table.macs);
 884     qemu_free(n->vlans);
 885
 886     qemu_del_timer(n->tx_timer);
 887     qemu_free_timer(n->tx_timer);
 888
 889     virtio_cleanup(&n->vdev);
 890     qemu_del_vlan_client(&n->nic->nc);
 891 }