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 "iov.h"
  15 #include "virtio.h"
  16 #include "net.h"
  17 #include "net/checksum.h"
  18 #include "net/tap.h"
  19 #include "qemu-error.h"
  20 #include "qemu-timer.h"
  21 #include "virtio-net.h"
  22 #include "vhost_net.h"
  23
  24 #define VIRTIO_NET_VM_VERSION    11
  25
  26 #define MAC_TABLE_ENTRIES    64
  27 #define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
  28
  29 typedef struct VirtIONet
  30 {
  31     VirtIODevice vdev;
  32     uint8_t mac[ETH_ALEN];
  33     uint16_t status;
  34     VirtQueue *rx_vq;
  35     VirtQueue *tx_vq;
  36     VirtQueue *ctrl_vq;
  37     NICState *nic;
  38     QEMUTimer *tx_timer;
  39     QEMUBH *tx_bh;
  40     uint32_t tx_timeout;
  41     int32_t tx_burst;
  42     int tx_waiting;
  43     uint32_t has_vnet_hdr;
  44     uint8_t has_ufo;
  45     struct {
  46         VirtQueueElement elem;
  47         ssize_t len;
  48     } async_tx;
  49     int mergeable_rx_bufs;
  50     uint8_t promisc;
  51     uint8_t allmulti;
  52     uint8_t alluni;
  53     uint8_t nomulti;
  54     uint8_t nouni;
  55     uint8_t nobcast;
  56     uint8_t vhost_started;
  57     struct {
  58         int in_use;
  59         int first_multi;
  60         uint8_t multi_overflow;
  61         uint8_t uni_overflow;
  62         uint8_t *macs;
  63     } mac_table;
  64     uint32_t *vlans;
  65     DeviceState *qdev;
  66 } VirtIONet;
  67
  68 /* TODO
  69  * - we could suppress RX interrupt if we were so inclined.
  70  */
  71
  72 static VirtIONet *to_virtio_net(VirtIODevice *vdev)
  73 {
  74     return (VirtIONet *)vdev;
  75 }
  76
  77 static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
  78 {
  79     VirtIONet *n = to_virtio_net(vdev);
  80     struct virtio_net_config netcfg;
  81
  82     netcfg.status = lduw_p(&n->status);
  83     memcpy(netcfg.mac, n->mac, ETH_ALEN);
  84     memcpy(config, &netcfg, sizeof(netcfg));
  85 }
  86
  87 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
  88 {
  89     VirtIONet *n = to_virtio_net(vdev);
  90     struct virtio_net_config netcfg;
  91
  92     memcpy(&netcfg, config, sizeof(netcfg));
  93
  94     if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
  95         memcpy(n->mac, netcfg.mac, ETH_ALEN);
  96         qemu_format_nic_info_str(&n->nic->nc, n->mac);
  97     }
  98 }
  99
 100 static bool virtio_net_started(VirtIONet *n, uint8_t status)
 101 {
 102     return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
 103         (n->status & VIRTIO_NET_S_LINK_UP) && n->vdev.vm_running;
 104 }
 105
 106 static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
 107 {
 108     if (!n->nic->nc.peer) {
 109         return;
 110     }
 111     if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
 112         return;
 113     }
 114
 115     if (!tap_get_vhost_net(n->nic->nc.peer)) {
 116         return;
 117     }
 118     if (!!n->vhost_started == virtio_net_started(n, status)) {
 119         return;
 120     }
 121     if (!n->vhost_started) {
 122         int r;
 123         if (!vhost_net_query(tap_get_vhost_net(n->nic->nc.peer), &n->vdev)) {
 124             return;
 125         }
 126         r = vhost_net_start(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
 127         if (r < 0) {
 128             error_report("unable to start vhost net: %d: "
 129                          "falling back on userspace virtio", -r);
 130         } else {
 131             n->vhost_started = 1;
 132         }
 133     } else {
 134         vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
 135         n->vhost_started = 0;
 136     }
 137 }
 138
 139 static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
 140 {
 141     VirtIONet *n = to_virtio_net(vdev);
 142
 143     virtio_net_vhost_status(n, status);
 144
 145     if (!n->tx_waiting) {
 146         return;
 147     }
 148
 149     if (virtio_net_started(n, status) && !n->vhost_started) {
 150         if (n->tx_timer) {
 151             qemu_mod_timer(n->tx_timer,
 152                            qemu_get_clock(vm_clock) + n->tx_timeout);
 153         } else {
 154             qemu_bh_schedule(n->tx_bh);
 155         }
 156     } else {
 157         if (n->tx_timer) {
 158             qemu_del_timer(n->tx_timer);
 159         } else {
 160             qemu_bh_cancel(n->tx_bh);
 161         }
 162     }
 163 }
 164
 165 static void virtio_net_set_link_status(VLANClientState *nc)
 166 {
 167     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
 168     uint16_t old_status = n->status;
 169
 170     if (nc->link_down)
 171         n->status &= ~VIRTIO_NET_S_LINK_UP;
 172     else
 173         n->status |= VIRTIO_NET_S_LINK_UP;
 174
 175     if (n->status != old_status)
 176         virtio_notify_config(&n->vdev);
 177
 178     virtio_net_set_status(&n->vdev, n->vdev.status);
 179 }
 180
 181 static void virtio_net_reset(VirtIODevice *vdev)
 182 {
 183     VirtIONet *n = to_virtio_net(vdev);
 184
 185     /* Reset back to compatibility mode */
 186     n->promisc = 1;
 187     n->allmulti = 0;
 188     n->alluni = 0;
 189     n->nomulti = 0;
 190     n->nouni = 0;
 191     n->nobcast = 0;
 192
 193     /* Flush any MAC and VLAN filter table state */
 194     n->mac_table.in_use = 0;
 195     n->mac_table.first_multi = 0;
 196     n->mac_table.multi_overflow = 0;
 197     n->mac_table.uni_overflow = 0;
 198     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
 199     memset(n->vlans, 0, MAX_VLAN >> 3);
 200 }
 201
 202 static int peer_has_vnet_hdr(VirtIONet *n)
 203 {
 204     if (!n->nic->nc.peer)
 205         return 0;
 206
 207     if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP)
 208         return 0;
 209
 210     n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
 211
 212     return n->has_vnet_hdr;
 213 }
 214
 215 static int peer_has_ufo(VirtIONet *n)
 216 {
 217     if (!peer_has_vnet_hdr(n))
 218         return 0;
 219
 220     n->has_ufo = tap_has_ufo(n->nic->nc.peer);
 221
 222     return n->has_ufo;
 223 }
 224
 225 static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
 226 {
 227     VirtIONet *n = to_virtio_net(vdev);
 228
 229     features |= (1 << VIRTIO_NET_F_MAC);
 230
 231     if (peer_has_vnet_hdr(n)) {
 232         tap_using_vnet_hdr(n->nic->nc.peer, 1);
 233     } else {
 234         features &= ~(0x1 << VIRTIO_NET_F_CSUM);
 235         features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO4);
 236         features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO6);
 237         features &= ~(0x1 << VIRTIO_NET_F_HOST_ECN);
 238
 239         features &= ~(0x1 << VIRTIO_NET_F_GUEST_CSUM);
 240         features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO4);
 241         features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO6);
 242         features &= ~(0x1 << VIRTIO_NET_F_GUEST_ECN);
 243     }
 244
 245     if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
 246         features &= ~(0x1 << VIRTIO_NET_F_GUEST_UFO);
 247         features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
 248     }
 249
 250     if (!n->nic->nc.peer ||
 251         n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
 252         return features;
 253     }
 254     if (!tap_get_vhost_net(n->nic->nc.peer)) {
 255         return features;
 256     }
 257     return vhost_net_get_features(tap_get_vhost_net(n->nic->nc.peer), features);
 258 }
 259
 260 static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
 261 {
 262     uint32_t features = 0;
 263
 264     /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
 265      * but also these: */
 266     features |= (1 << VIRTIO_NET_F_MAC);
 267     features |= (1 << VIRTIO_NET_F_CSUM);
 268     features |= (1 << VIRTIO_NET_F_HOST_TSO4);
 269     features |= (1 << VIRTIO_NET_F_HOST_TSO6);
 270     features |= (1 << VIRTIO_NET_F_HOST_ECN);
 271
 272     return features;
 273 }
 274
 275 static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
 276 {
 277     VirtIONet *n = to_virtio_net(vdev);
 278
 279     n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
 280
 281     if (n->has_vnet_hdr) {
 282         tap_set_offload(n->nic->nc.peer,
 283                         (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
 284                         (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
 285                         (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
 286                         (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
 287                         (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
 288     }
 289     if (!n->nic->nc.peer ||
 290         n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
 291         return;
 292     }
 293     if (!tap_get_vhost_net(n->nic->nc.peer)) {
 294         return;
 295     }
 296     vhost_net_ack_features(tap_get_vhost_net(n->nic->nc.peer), features);
 297 }
 298
 299 static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
 300                                      VirtQueueElement *elem)
 301 {
 302     uint8_t on;
 303
 304     if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {
 305         error_report("virtio-net ctrl invalid rx mode command");
 306         exit(1);
 307     }
 308
 309     on = ldub_p(elem->out_sg[1].iov_base);
 310
 311     if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)
 312         n->promisc = on;
 313     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
 314         n->allmulti = on;
 315     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLUNI)
 316         n->alluni = on;
 317     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOMULTI)
 318         n->nomulti = on;
 319     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOUNI)
 320         n->nouni = on;
 321     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOBCAST)
 322         n->nobcast = on;
 323     else
 324         return VIRTIO_NET_ERR;
 325
 326     return VIRTIO_NET_OK;
 327 }
 328
 329 static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
 330                                  VirtQueueElement *elem)
 331 {
 332     struct virtio_net_ctrl_mac mac_data;
 333
 334     if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET || elem->out_num != 3 ||
 335         elem->out_sg[1].iov_len < sizeof(mac_data) ||
 336         elem->out_sg[2].iov_len < sizeof(mac_data))
 337         return VIRTIO_NET_ERR;
 338
 339     n->mac_table.in_use = 0;
 340     n->mac_table.first_multi = 0;
 341     n->mac_table.uni_overflow = 0;
 342     n->mac_table.multi_overflow = 0;
 343     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
 344
 345     mac_data.entries = ldl_p(elem->out_sg[1].iov_base);
 346
 347     if (sizeof(mac_data.entries) +
 348         (mac_data.entries * ETH_ALEN) > elem->out_sg[1].iov_len)
 349         return VIRTIO_NET_ERR;
 350
 351     if (mac_data.entries <= MAC_TABLE_ENTRIES) {
 352         memcpy(n->mac_table.macs, elem->out_sg[1].iov_base + sizeof(mac_data),
 353                mac_data.entries * ETH_ALEN);
 354         n->mac_table.in_use += mac_data.entries;
 355     } else {
 356         n->mac_table.uni_overflow = 1;
 357     }
 358
 359     n->mac_table.first_multi = n->mac_table.in_use;
 360
 361     mac_data.entries = ldl_p(elem->out_sg[2].iov_base);
 362
 363     if (sizeof(mac_data.entries) +
 364         (mac_data.entries * ETH_ALEN) > elem->out_sg[2].iov_len)
 365         return VIRTIO_NET_ERR;
 366
 367     if (mac_data.entries) {
 368         if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
 369             memcpy(n->mac_table.macs + (n->mac_table.in_use * ETH_ALEN),
 370                    elem->out_sg[2].iov_base + sizeof(mac_data),
 371                    mac_data.entries * ETH_ALEN);
 372             n->mac_table.in_use += mac_data.entries;
 373         } else {
 374             n->mac_table.multi_overflow = 1;
 375         }
 376     }
 377
 378     return VIRTIO_NET_OK;
 379 }
 380
 381 static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
 382                                         VirtQueueElement *elem)
 383 {
 384     uint16_t vid;
 385
 386     if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(vid)) {
 387         error_report("virtio-net ctrl invalid vlan command");
 388         return VIRTIO_NET_ERR;
 389     }
 390
 391     vid = lduw_p(elem->out_sg[1].iov_base);
 392
 393     if (vid >= MAX_VLAN)
 394         return VIRTIO_NET_ERR;
 395
 396     if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
 397         n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
 398     else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
 399         n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
 400     else
 401         return VIRTIO_NET_ERR;
 402
 403     return VIRTIO_NET_OK;
 404 }
 405
 406 static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 407 {
 408     VirtIONet *n = to_virtio_net(vdev);
 409     struct virtio_net_ctrl_hdr ctrl;
 410     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
 411     VirtQueueElement elem;
 412
 413     while (virtqueue_pop(vq, &elem)) {
 414         if ((elem.in_num < 1) || (elem.out_num < 1)) {
 415             error_report("virtio-net ctrl missing headers");
 416             exit(1);
 417         }
 418
 419         if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
 420             elem.in_sg[elem.in_num - 1].iov_len < sizeof(status)) {
 421             error_report("virtio-net ctrl header not in correct element");
 422             exit(1);
 423         }
 424
 425         ctrl.class = ldub_p(elem.out_sg[0].iov_base);
 426         ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
 427
 428         if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)
 429             status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);
 430         else if (ctrl.class == VIRTIO_NET_CTRL_MAC)
 431             status = virtio_net_handle_mac(n, ctrl.cmd, &elem);
 432         else if (ctrl.class == VIRTIO_NET_CTRL_VLAN)
 433             status = virtio_net_handle_vlan_table(n, ctrl.cmd, &elem);
 434
 435         stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
 436
 437         virtqueue_push(vq, &elem, sizeof(status));
 438         virtio_notify(vdev, vq);
 439     }
 440 }
 441
 442 /* RX */
 443
 444 static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
 445 {
 446     VirtIONet *n = to_virtio_net(vdev);
 447
 448     qemu_flush_queued_packets(&n->nic->nc);
 449
 450     /* We now have RX buffers, signal to the IO thread to break out of the
 451      * select to re-poll the tap file descriptor */
 452     qemu_notify_event();
 453 }
 454
 455 static int virtio_net_can_receive(VLANClientState *nc)
 456 {
 457     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
 458     if (!n->vdev.vm_running) {
 459         return 0;
 460     }
 461
 462     if (!virtio_queue_ready(n->rx_vq) ||
 463         !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 464         return 0;
 465
 466     return 1;
 467 }
 468
 469 static int virtio_net_has_buffers(VirtIONet *n, int bufsize)
 470 {
 471     if (virtio_queue_empty(n->rx_vq) ||
 472         (n->mergeable_rx_bufs &&
 473          !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
 474         virtio_queue_set_notification(n->rx_vq, 1);
 475
 476         /* To avoid a race condition where the guest has made some buffers
 477          * available after the above check but before notification was
 478          * enabled, check for available buffers again.
 479          */
 480         if (virtio_queue_empty(n->rx_vq) ||
 481             (n->mergeable_rx_bufs &&
 482              !virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))
 483             return 0;
 484     }
 485
 486     virtio_queue_set_notification(n->rx_vq, 0);
 487     return 1;
 488 }
 489
 490 /* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
 491  * it never finds out that the packets don't have valid checksums.  This
 492  * causes dhclient to get upset.  Fedora's carried a patch for ages to
 493  * fix this with Xen but it hasn't appeared in an upstream release of
 494  * dhclient yet.
 495  *
 496  * To avoid breaking existing guests, we catch udp packets and add
 497  * checksums.  This is terrible but it's better than hacking the guest
 498  * kernels.
 499  *
 500  * N.B. if we introduce a zero-copy API, this operation is no longer free so
 501  * we should provide a mechanism to disable it to avoid polluting the host
 502  * cache.
 503  */
 504 static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
 505                                         const uint8_t *buf, size_t size)
 506 {
 507     if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
 508         (size > 27 && size < 1500) && /* normal sized MTU */
 509         (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
 510         (buf[23] == 17) && /* ip.protocol == UDP */
 511         (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
 512         /* FIXME this cast is evil */
 513         net_checksum_calculate((uint8_t *)buf, size);
 514         hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
 515     }
 516 }
 517
 518 static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
 519                           const void *buf, size_t size, size_t hdr_len)
 520 {
 521     struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)iov[0].iov_base;
 522     int offset = 0;
 523
 524     hdr->flags = 0;
 525     hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
 526
 527     if (n->has_vnet_hdr) {
 528         memcpy(hdr, buf, sizeof(*hdr));
 529         offset = sizeof(*hdr);
 530         work_around_broken_dhclient(hdr, buf + offset, size - offset);
 531     }
 532
 533     /* We only ever receive a struct virtio_net_hdr from the tapfd,
 534      * but we may be passing along a larger header to the guest.
 535      */
 536     iov[0].iov_base += hdr_len;
 537     iov[0].iov_len  -= hdr_len;
 538
 539     return offset;
 540 }
 541
 542 static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
 543 {
 544     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 545     static const uint8_t vlan[] = {0x81, 0x00};
 546     uint8_t *ptr = (uint8_t *)buf;
 547     int i;
 548
 549     if (n->promisc)
 550         return 1;
 551
 552     if (n->has_vnet_hdr) {
 553         ptr += sizeof(struct virtio_net_hdr);
 554     }
 555
 556     if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
 557         int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
 558         if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
 559             return 0;
 560     }
 561
 562     if (ptr[0] & 1) { // multicast
 563         if (!memcmp(ptr, bcast, sizeof(bcast))) {
 564             return !n->nobcast;
 565         } else if (n->nomulti) {
 566             return 0;
 567         } else if (n->allmulti || n->mac_table.multi_overflow) {
 568             return 1;
 569         }
 570
 571         for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
 572             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
 573                 return 1;
 574             }
 575         }
 576     } else { // unicast
 577         if (n->nouni) {
 578             return 0;
 579         } else if (n->alluni || n->mac_table.uni_overflow) {
 580             return 1;
 581         } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
 582             return 1;
 583         }
 584
 585         for (i = 0; i < n->mac_table.first_multi; i++) {
 586             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
 587                 return 1;
 588             }
 589         }
 590     }
 591
 592     return 0;
 593 }
 594
 595 static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
 596 {
 597     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
 598     struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
 599     size_t guest_hdr_len, offset, i, host_hdr_len;
 600
 601     if (!virtio_net_can_receive(&n->nic->nc))
 602         return -1;
 603
 604     /* hdr_len refers to the header we supply to the guest */
 605     guest_hdr_len = n->mergeable_rx_bufs ?
 606         sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
 607
 608
 609     host_hdr_len = n->has_vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
 610     if (!virtio_net_has_buffers(n, size + guest_hdr_len - host_hdr_len))
 611         return 0;
 612
 613     if (!receive_filter(n, buf, size))
 614         return size;
 615
 616     offset = i = 0;
 617
 618     while (offset < size) {
 619         VirtQueueElement elem;
 620         int len, total;
 621         struct iovec sg[VIRTQUEUE_MAX_SIZE];
 622
 623         total = 0;
 624
 625         if (virtqueue_pop(n->rx_vq, &elem) == 0) {
 626             if (i == 0)
 627                 return -1;
 628             error_report("virtio-net unexpected empty queue: "
 629                     "i %zd mergeable %d offset %zd, size %zd, "
 630                     "guest hdr len %zd, host hdr len %zd guest features 0x%x",
 631                     i, n->mergeable_rx_bufs, offset, size,
 632                     guest_hdr_len, host_hdr_len, n->vdev.guest_features);
 633             exit(1);
 634         }
 635
 636         if (elem.in_num < 1) {
 637             error_report("virtio-net receive queue contains no in buffers");
 638             exit(1);
 639         }
 640
 641         if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != guest_hdr_len) {
 642             error_report("virtio-net header not in first element");
 643             exit(1);
 644         }
 645
 646         memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num);
 647
 648         if (i == 0) {
 649             if (n->mergeable_rx_bufs)
 650                 mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base;
 651
 652             offset += receive_header(n, sg, elem.in_num,
 653                                      buf + offset, size - offset, guest_hdr_len);
 654             total += guest_hdr_len;
 655         }
 656
 657         /* copy in packet.  ugh */
 658         len = iov_from_buf(sg, elem.in_num,
 659                            buf + offset, size - offset);
 660         total += len;
 661         offset += len;
 662         /* If buffers can't be merged, at this point we
 663          * must have consumed the complete packet.
 664          * Otherwise, drop it. */
 665         if (!n->mergeable_rx_bufs && offset < size) {
 666 #if 0
 667             error_report("virtio-net truncated non-mergeable packet: "
 668                          "i %zd mergeable %d offset %zd, size %zd, "
 669                          "guest hdr len %zd, host hdr len %zd",
 670                          i, n->mergeable_rx_bufs,
 671                          offset, size, guest_hdr_len, host_hdr_len);
 672 #endif
 673             return size;
 674         }
 675
 676         /* signal other side */
 677         virtqueue_fill(n->rx_vq, &elem, total, i++);
 678     }
 679
 680     if (mhdr) {
 681         mhdr->num_buffers = lduw_p(&i);
 682     }
 683
 684     virtqueue_flush(n->rx_vq, i);
 685     virtio_notify(&n->vdev, n->rx_vq);
 686
 687     return size;
 688 }
 689
 690 static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
 691
 692 static void virtio_net_tx_complete(VLANClientState *nc, ssize_t len)
 693 {
 694     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
 695
 696     virtqueue_push(n->tx_vq, &n->async_tx.elem, n->async_tx.len);
 697     virtio_notify(&n->vdev, n->tx_vq);
 698
 699     n->async_tx.elem.out_num = n->async_tx.len = 0;
 700
 701     virtio_queue_set_notification(n->tx_vq, 1);
 702     virtio_net_flush_tx(n, n->tx_vq);
 703 }
 704
 705 /* TX */
 706 static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
 707 {
 708     VirtQueueElement elem;
 709     int32_t num_packets = 0;
 710     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 711         return num_packets;
 712     }
 713
 714     assert(n->vdev.vm_running);
 715
 716     if (n->async_tx.elem.out_num) {
 717         virtio_queue_set_notification(n->tx_vq, 0);
 718         return num_packets;
 719     }
 720
 721     while (virtqueue_pop(vq, &elem)) {
 722         ssize_t ret, len = 0;
 723         unsigned int out_num = elem.out_num;
 724         struct iovec *out_sg = &elem.out_sg[0];
 725         unsigned hdr_len;
 726
 727         /* hdr_len refers to the header received from the guest */
 728         hdr_len = n->mergeable_rx_bufs ?
 729             sizeof(struct virtio_net_hdr_mrg_rxbuf) :
 730             sizeof(struct virtio_net_hdr);
 731
 732         if (out_num < 1 || out_sg->iov_len != hdr_len) {
 733             error_report("virtio-net header not in first element");
 734             exit(1);
 735         }
 736
 737         /* ignore the header if GSO is not supported */
 738         if (!n->has_vnet_hdr) {
 739             out_num--;
 740             out_sg++;
 741             len += hdr_len;
 742         } else if (n->mergeable_rx_bufs) {
 743             /* tapfd expects a struct virtio_net_hdr */
 744             hdr_len -= sizeof(struct virtio_net_hdr);
 745             out_sg->iov_len -= hdr_len;
 746             len += hdr_len;
 747         }
 748
 749         ret = qemu_sendv_packet_async(&n->nic->nc, out_sg, out_num,
 750                                       virtio_net_tx_complete);
 751         if (ret == 0) {
 752             virtio_queue_set_notification(n->tx_vq, 0);
 753             n->async_tx.elem = elem;
 754             n->async_tx.len  = len;
 755             return -EBUSY;
 756         }
 757
 758         len += ret;
 759
 760         virtqueue_push(vq, &elem, len);
 761         virtio_notify(&n->vdev, vq);
 762
 763         if (++num_packets >= n->tx_burst) {
 764             break;
 765         }
 766     }
 767     return num_packets;
 768 }
 769
 770 static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
 771 {
 772     VirtIONet *n = to_virtio_net(vdev);
 773
 774     /* This happens when device was stopped but VCPU wasn't. */
 775     if (!n->vdev.vm_running) {
 776         n->tx_waiting = 1;
 777         return;
 778     }
 779
 780     if (n->tx_waiting) {
 781         virtio_queue_set_notification(vq, 1);
 782         qemu_del_timer(n->tx_timer);
 783         n->tx_waiting = 0;
 784         virtio_net_flush_tx(n, vq);
 785     } else {
 786         qemu_mod_timer(n->tx_timer,
 787                        qemu_get_clock(vm_clock) + n->tx_timeout);
 788         n->tx_waiting = 1;
 789         virtio_queue_set_notification(vq, 0);
 790     }
 791 }
 792
 793 static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
 794 {
 795     VirtIONet *n = to_virtio_net(vdev);
 796
 797     if (unlikely(n->tx_waiting)) {
 798         return;
 799     }
 800     n->tx_waiting = 1;
 801     /* This happens when device was stopped but VCPU wasn't. */
 802     if (!n->vdev.vm_running) {
 803         return;
 804     }
 805     virtio_queue_set_notification(vq, 0);
 806     qemu_bh_schedule(n->tx_bh);
 807 }
 808
 809 static void virtio_net_tx_timer(void *opaque)
 810 {
 811     VirtIONet *n = opaque;
 812     assert(n->vdev.vm_running);
 813
 814     n->tx_waiting = 0;
 815
 816     /* Just in case the driver is not ready on more */
 817     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 818         return;
 819
 820     virtio_queue_set_notification(n->tx_vq, 1);
 821     virtio_net_flush_tx(n, n->tx_vq);
 822 }
 823
 824 static void virtio_net_tx_bh(void *opaque)
 825 {
 826     VirtIONet *n = opaque;
 827     int32_t ret;
 828
 829     assert(n->vdev.vm_running);
 830
 831     n->tx_waiting = 0;
 832
 833     /* Just in case the driver is not ready on more */
 834     if (unlikely(!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)))
 835         return;
 836
 837     ret = virtio_net_flush_tx(n, n->tx_vq);
 838     if (ret == -EBUSY) {
 839         return; /* Notification re-enable handled by tx_complete */
 840     }
 841
 842     /* If we flush a full burst of packets, assume there are
 843      * more coming and immediately reschedule */
 844     if (ret >= n->tx_burst) {
 845         qemu_bh_schedule(n->tx_bh);
 846         n->tx_waiting = 1;
 847         return;
 848     }
 849
 850     /* If less than a full burst, re-enable notification and flush
 851      * anything that may have come in while we weren't looking.  If
 852      * we find something, assume the guest is still active and reschedule */
 853     virtio_queue_set_notification(n->tx_vq, 1);
 854     if (virtio_net_flush_tx(n, n->tx_vq) > 0) {
 855         virtio_queue_set_notification(n->tx_vq, 0);
 856         qemu_bh_schedule(n->tx_bh);
 857         n->tx_waiting = 1;
 858     }
 859 }
 860
 861 static void virtio_net_save(QEMUFile *f, void *opaque)
 862 {
 863     VirtIONet *n = opaque;
 864
 865     /* At this point, backend must be stopped, otherwise
 866      * it might keep writing to memory. */
 867     assert(!n->vhost_started);
 868     virtio_save(&n->vdev, f);
 869
 870     qemu_put_buffer(f, n->mac, ETH_ALEN);
 871     qemu_put_be32(f, n->tx_waiting);
 872     qemu_put_be32(f, n->mergeable_rx_bufs);
 873     qemu_put_be16(f, n->status);
 874     qemu_put_byte(f, n->promisc);
 875     qemu_put_byte(f, n->allmulti);
 876     qemu_put_be32(f, n->mac_table.in_use);
 877     qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
 878     qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
 879     qemu_put_be32(f, n->has_vnet_hdr);
 880     qemu_put_byte(f, n->mac_table.multi_overflow);
 881     qemu_put_byte(f, n->mac_table.uni_overflow);
 882     qemu_put_byte(f, n->alluni);
 883     qemu_put_byte(f, n->nomulti);
 884     qemu_put_byte(f, n->nouni);
 885     qemu_put_byte(f, n->nobcast);
 886     qemu_put_byte(f, n->has_ufo);
 887 }
 888
 889 static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
 890 {
 891     VirtIONet *n = opaque;
 892     int i;
 893
 894     if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
 895         return -EINVAL;
 896
 897     virtio_load(&n->vdev, f);
 898
 899     qemu_get_buffer(f, n->mac, ETH_ALEN);
 900     n->tx_waiting = qemu_get_be32(f);
 901     n->mergeable_rx_bufs = qemu_get_be32(f);
 902
 903     if (version_id >= 3)
 904         n->status = qemu_get_be16(f);
 905
 906     if (version_id >= 4) {
 907         if (version_id < 8) {
 908             n->promisc = qemu_get_be32(f);
 909             n->allmulti = qemu_get_be32(f);
 910         } else {
 911             n->promisc = qemu_get_byte(f);
 912             n->allmulti = qemu_get_byte(f);
 913         }
 914     }
 915
 916     if (version_id >= 5) {
 917         n->mac_table.in_use = qemu_get_be32(f);
 918         /* MAC_TABLE_ENTRIES may be different from the saved image */
 919         if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
 920             qemu_get_buffer(f, n->mac_table.macs,
 921                             n->mac_table.in_use * ETH_ALEN);
 922         } else if (n->mac_table.in_use) {
 923             qemu_fseek(f, n->mac_table.in_use * ETH_ALEN, SEEK_CUR);
 924             n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
 925             n->mac_table.in_use = 0;
 926         }
 927     }
 928
 929     if (version_id >= 6)
 930         qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
 931
 932     if (version_id >= 7) {
 933         if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
 934             error_report("virtio-net: saved image requires vnet_hdr=on");
 935             return -1;
 936         }
 937
 938         if (n->has_vnet_hdr) {
 939             tap_using_vnet_hdr(n->nic->nc.peer, 1);
 940             tap_set_offload(n->nic->nc.peer,
 941                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
 942                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
 943                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
 944                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
 945                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
 946         }
 947     }
 948
 949     if (version_id >= 9) {
 950         n->mac_table.multi_overflow = qemu_get_byte(f);
 951         n->mac_table.uni_overflow = qemu_get_byte(f);
 952     }
 953
 954     if (version_id >= 10) {
 955         n->alluni = qemu_get_byte(f);
 956         n->nomulti = qemu_get_byte(f);
 957         n->nouni = qemu_get_byte(f);
 958         n->nobcast = qemu_get_byte(f);
 959     }
 960
 961     if (version_id >= 11) {
 962         if (qemu_get_byte(f) && !peer_has_ufo(n)) {
 963             error_report("virtio-net: saved image requires TUN_F_UFO support");
 964             return -1;
 965         }
 966     }
 967
 968     /* Find the first multicast entry in the saved MAC filter */
 969     for (i = 0; i < n->mac_table.in_use; i++) {
 970         if (n->mac_table.macs[i * ETH_ALEN] & 1) {
 971             break;
 972         }
 973     }
 974     n->mac_table.first_multi = i;
 975     return 0;
 976 }
 977
 978 static void virtio_net_cleanup(VLANClientState *nc)
 979 {
 980     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
 981
 982     n->nic = NULL;
 983 }
 984
 985 static NetClientInfo net_virtio_info = {
 986     .type = NET_CLIENT_TYPE_NIC,
 987     .size = sizeof(NICState),
 988     .can_receive = virtio_net_can_receive,
 989     .receive = virtio_net_receive,
 990         .cleanup = virtio_net_cleanup,
 991     .link_status_changed = virtio_net_set_link_status,
 992 };
 993
 994 VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
 995                               virtio_net_conf *net)
 996 {
 997     VirtIONet *n;
 998
 999     n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
1000                                         sizeof(struct virtio_net_config),
1001                                         sizeof(VirtIONet));
1002
1003     n->vdev.get_config = virtio_net_get_config;
1004     n->vdev.set_config = virtio_net_set_config;
1005     n->vdev.get_features = virtio_net_get_features;
1006     n->vdev.set_features = virtio_net_set_features;
1007     n->vdev.bad_features = virtio_net_bad_features;
1008     n->vdev.reset = virtio_net_reset;
1009     n->vdev.set_status = virtio_net_set_status;
1010     n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
1011
1012     if (net->tx && strcmp(net->tx, "timer") && strcmp(net->tx, "bh")) {
1013         error_report("virtio-net: "
1014                      "Unknown option tx=%s, valid options: \"timer\" \"bh\"",
1015                      net->tx);
1016         error_report("Defaulting to \"bh\"");
1017     }
1018
1019     if (net->tx && !strcmp(net->tx, "timer")) {
1020         n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_timer);
1021         n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);
1022         n->tx_timeout = net->txtimer;
1023     } else {
1024         n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_bh);
1025         n->tx_bh = qemu_bh_new(virtio_net_tx_bh, n);
1026     }
1027     n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
1028     qemu_macaddr_default_if_unset(&conf->macaddr);
1029     memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
1030     n->status = VIRTIO_NET_S_LINK_UP;
1031
1032     n->nic = qemu_new_nic(&net_virtio_info, conf, dev->info->name, dev->id, n);
1033
1034     qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
1035
1036     n->tx_waiting = 0;
1037     n->tx_burst = net->txburst;
1038     n->mergeable_rx_bufs = 0;
1039     n->promisc = 1; /* for compatibility */
1040
1041     n->mac_table.macs = qemu_mallocz(MAC_TABLE_ENTRIES * ETH_ALEN);
1042
1043     n->vlans = qemu_mallocz(MAX_VLAN >> 3);
1044
1045     n->qdev = dev;
1046     register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
1047                     virtio_net_save, virtio_net_load, n);
1048
1049     add_boot_device_path(conf->bootindex, dev, "/ethernet-phy@0");
1050
1051     return &n->vdev;
1052 }
1053
1054 void virtio_net_exit(VirtIODevice *vdev)
1055 {
1056     VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
1057
1058     /* This will stop vhost backend if appropriate. */
1059     virtio_net_set_status(vdev, 0);
1060
1061     qemu_purge_queued_packets(&n->nic->nc);
1062
1063     unregister_savevm(n->qdev, "virtio-net", n);
1064
1065     qemu_free(n->mac_table.macs);
1066     qemu_free(n->vlans);
1067
1068     if (n->tx_timer) {
1069         qemu_del_timer(n->tx_timer);
1070         qemu_free_timer(n->tx_timer);
1071     } else {
1072         qemu_bh_delete(n->tx_bh);
1073     }
1074
1075     virtio_cleanup(&n->vdev);
1076     qemu_del_vlan_client(&n->nic->nc);
1077 }