hw/net/vhost_net.c

   1 /*
   2  * vhost-net support
   3  *
   4  * Copyright Red Hat, Inc. 2010
   5  *
   6  * Authors:
   7  *  Michael S. Tsirkin <mst@redhat.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  * Contributions after 2012-01-13 are licensed under the terms of the
  13  * GNU GPL, version 2 or (at your option) any later version.
  14  */
  15
  16 #include "net/net.h"
  17 #include "net/tap.h"
  18 #include "net/vhost-user.h"
  19
  20 #include "hw/virtio/virtio-net.h"
  21 #include "net/vhost_net.h"
  22 #include "qemu/error-report.h"
  23
  24 #include "config.h"
  25
  26 #ifdef CONFIG_VHOST_NET
  27 #include <linux/vhost.h>
  28 #include <sys/socket.h>
  29 #include <linux/kvm.h>
  30 #include <fcntl.h>
  31 #include <netpacket/packet.h>
  32 #include <net/ethernet.h>
  33 #include <net/if.h>
  34 #include <netinet/in.h>
  35
  36 #include <stdio.h>
  37
  38 #include "standard-headers/linux/virtio_ring.h"
  39 #include "hw/virtio/vhost.h"
  40 #include "hw/virtio/virtio-bus.h"
  41 #include "hw/virtio/virtio-access.h"
  42
  43 struct vhost_net {
  44     struct vhost_dev dev;
  45     struct vhost_virtqueue vqs[2];
  46     int backend;
  47     NetClientState *nc;
  48 };
  49
  50 /* Features supported by host kernel. */
  51 static const int kernel_feature_bits[] = {
  52     VIRTIO_F_NOTIFY_ON_EMPTY,
  53     VIRTIO_RING_F_INDIRECT_DESC,
  54     VIRTIO_RING_F_EVENT_IDX,
  55     VIRTIO_NET_F_MRG_RXBUF,
  56     VIRTIO_F_VERSION_1,
  57     VHOST_INVALID_FEATURE_BIT
  58 };
  59
  60 /* Features supported by others. */
  61 static const int user_feature_bits[] = {
  62     VIRTIO_F_NOTIFY_ON_EMPTY,
  63     VIRTIO_RING_F_INDIRECT_DESC,
  64     VIRTIO_RING_F_EVENT_IDX,
  65
  66     VIRTIO_F_ANY_LAYOUT,
  67     VIRTIO_F_VERSION_1,
  68     VIRTIO_NET_F_CSUM,
  69     VIRTIO_NET_F_GUEST_CSUM,
  70     VIRTIO_NET_F_GSO,
  71     VIRTIO_NET_F_GUEST_TSO4,
  72     VIRTIO_NET_F_GUEST_TSO6,
  73     VIRTIO_NET_F_GUEST_ECN,
  74     VIRTIO_NET_F_GUEST_UFO,
  75     VIRTIO_NET_F_HOST_TSO4,
  76     VIRTIO_NET_F_HOST_TSO6,
  77     VIRTIO_NET_F_HOST_ECN,
  78     VIRTIO_NET_F_HOST_UFO,
  79     VIRTIO_NET_F_MRG_RXBUF,
  80
  81     /* This bit implies RARP isn't sent by QEMU out of band */
  82     VIRTIO_NET_F_GUEST_ANNOUNCE,
  83
  84     VIRTIO_NET_F_MQ,
  85
  86     VHOST_INVALID_FEATURE_BIT
  87 };
  88
  89 static const int *vhost_net_get_feature_bits(struct vhost_net *net)
  90 {
  91     const int *feature_bits = 0;
  92
  93     switch (net->nc->info->type) {
  94     case NET_CLIENT_OPTIONS_KIND_TAP:
  95         feature_bits = kernel_feature_bits;
  96         break;
  97     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
  98         feature_bits = user_feature_bits;
  99         break;
 100     default:
 101         error_report("Feature bits not defined for this type: %d",
 102                 net->nc->info->type);
 103         break;
 104     }
 105
 106     return feature_bits;
 107 }
 108
 109 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
 110 {
 111     return vhost_get_features(&net->dev, vhost_net_get_feature_bits(net),
 112             features);
 113 }
 114
 115 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
 116 {
 117     net->dev.acked_features = net->dev.backend_features;
 118     vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
 119 }
 120
 121 uint64_t vhost_net_get_max_queues(VHostNetState *net)
 122 {
 123     return net->dev.max_queues;
 124 }
 125
 126 static int vhost_net_get_fd(NetClientState *backend)
 127 {
 128     switch (backend->info->type) {
 129     case NET_CLIENT_OPTIONS_KIND_TAP:
 130         return tap_get_fd(backend);
 131     default:
 132         fprintf(stderr, "vhost-net requires tap backend\n");
 133         return -EBADFD;
 134     }
 135 }
 136
 137 struct vhost_net *vhost_net_init(VhostNetOptions *options)
 138 {
 139     int r;
 140     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
 141     struct vhost_net *net = g_malloc(sizeof *net);
 142
 143     if (!options->net_backend) {
 144         fprintf(stderr, "vhost-net requires net backend to be setup\n");
 145         goto fail;
 146     }
 147     net->nc = options->net_backend;
 148
 149     net->dev.max_queues = 1;
 150     net->dev.nvqs = 2;
 151     net->dev.vqs = net->vqs;
 152
 153     if (backend_kernel) {
 154         r = vhost_net_get_fd(options->net_backend);
 155         if (r < 0) {
 156             goto fail;
 157         }
 158         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
 159             ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
 160         net->backend = r;
 161         net->dev.protocol_features = 0;
 162     } else {
 163         net->dev.backend_features = 0;
 164         net->dev.protocol_features = 0;
 165         net->backend = -1;
 166
 167         /* vhost-user needs vq_index to initiate a specific queue pair */
 168         net->dev.vq_index = net->nc->queue_index * net->dev.nvqs;
 169     }
 170
 171     r = vhost_dev_init(&net->dev, options->opaque,
 172                        options->backend_type);
 173     if (r < 0) {
 174         goto fail;
 175     }
 176     if (backend_kernel) {
 177         if (!qemu_has_vnet_hdr_len(options->net_backend,
 178                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
 179             net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
 180         }
 181         if (~net->dev.features & net->dev.backend_features) {
 182             fprintf(stderr, "vhost lacks feature mask %" PRIu64
 183                    " for backend\n",
 184                    (uint64_t)(~net->dev.features & net->dev.backend_features));
 185             vhost_dev_cleanup(&net->dev);
 186             goto fail;
 187         }
 188     }
 189     /* Set sane init value. Override when guest acks. */
 190     vhost_net_ack_features(net, 0);
 191     return net;
 192 fail:
 193     g_free(net);
 194     return NULL;
 195 }
 196
 197 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
 198 {
 199     net->dev.vq_index = vq_index;
 200 }
 201
 202 static int vhost_net_set_vnet_endian(VirtIODevice *dev, NetClientState *peer,
 203                                      bool set)
 204 {
 205     int r = 0;
 206
 207     if (virtio_vdev_has_feature(dev, VIRTIO_F_VERSION_1) ||
 208         (virtio_legacy_is_cross_endian(dev) && !virtio_is_big_endian(dev))) {
 209         r = qemu_set_vnet_le(peer, set);
 210         if (r) {
 211             error_report("backend does not support LE vnet headers");
 212         }
 213     } else if (virtio_legacy_is_cross_endian(dev)) {
 214         r = qemu_set_vnet_be(peer, set);
 215         if (r) {
 216             error_report("backend does not support BE vnet headers");
 217         }
 218     }
 219
 220     return r;
 221 }
 222
 223 static int vhost_net_start_one(struct vhost_net *net,
 224                                VirtIODevice *dev)
 225 {
 226     struct vhost_vring_file file = { };
 227     int r;
 228
 229     net->dev.nvqs = 2;
 230     net->dev.vqs = net->vqs;
 231
 232     r = vhost_dev_enable_notifiers(&net->dev, dev);
 233     if (r < 0) {
 234         goto fail_notifiers;
 235     }
 236
 237     r = vhost_dev_start(&net->dev, dev);
 238     if (r < 0) {
 239         goto fail_start;
 240     }
 241
 242     if (net->nc->info->poll) {
 243         net->nc->info->poll(net->nc, false);
 244     }
 245
 246     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
 247         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
 248         file.fd = net->backend;
 249         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
 250             const VhostOps *vhost_ops = net->dev.vhost_ops;
 251             r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
 252             if (r < 0) {
 253                 r = -errno;
 254                 goto fail;
 255             }
 256         }
 257     }
 258     return 0;
 259 fail:
 260     file.fd = -1;
 261     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
 262         while (file.index-- > 0) {
 263             const VhostOps *vhost_ops = net->dev.vhost_ops;
 264             int r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
 265             assert(r >= 0);
 266         }
 267     }
 268     if (net->nc->info->poll) {
 269         net->nc->info->poll(net->nc, true);
 270     }
 271     vhost_dev_stop(&net->dev, dev);
 272 fail_start:
 273     vhost_dev_disable_notifiers(&net->dev, dev);
 274 fail_notifiers:
 275     return r;
 276 }
 277
 278 static void vhost_net_stop_one(struct vhost_net *net,
 279                                VirtIODevice *dev)
 280 {
 281     struct vhost_vring_file file = { .fd = -1 };
 282
 283     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
 284         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
 285             const VhostOps *vhost_ops = net->dev.vhost_ops;
 286             int r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
 287             assert(r >= 0);
 288         }
 289     }
 290     if (net->nc->info->poll) {
 291         net->nc->info->poll(net->nc, true);
 292     }
 293     vhost_dev_stop(&net->dev, dev);
 294     vhost_dev_disable_notifiers(&net->dev, dev);
 295 }
 296
 297 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
 298                     int total_queues)
 299 {
 300     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
 301     VirtioBusState *vbus = VIRTIO_BUS(qbus);
 302     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
 303     int r, e, i;
 304
 305     if (!k->set_guest_notifiers) {
 306         error_report("binding does not support guest notifiers");
 307         r = -ENOSYS;
 308         goto err;
 309     }
 310
 311     r = vhost_net_set_vnet_endian(dev, ncs[0].peer, true);
 312     if (r < 0) {
 313         goto err;
 314     }
 315
 316     for (i = 0; i < total_queues; i++) {
 317         vhost_net_set_vq_index(get_vhost_net(ncs[i].peer), i * 2);
 318     }
 319
 320     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
 321     if (r < 0) {
 322         error_report("Error binding guest notifier: %d", -r);
 323         goto err_endian;
 324     }
 325
 326     for (i = 0; i < total_queues; i++) {
 327         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
 328
 329         if (r < 0) {
 330             goto err_start;
 331         }
 332     }
 333
 334     return 0;
 335
 336 err_start:
 337     while (--i >= 0) {
 338         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
 339     }
 340     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
 341     if (e < 0) {
 342         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
 343         fflush(stderr);
 344     }
 345 err_endian:
 346     vhost_net_set_vnet_endian(dev, ncs[0].peer, false);
 347 err:
 348     return r;
 349 }
 350
 351 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
 352                     int total_queues)
 353 {
 354     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
 355     VirtioBusState *vbus = VIRTIO_BUS(qbus);
 356     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
 357     int i, r;
 358
 359     for (i = 0; i < total_queues; i++) {
 360         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
 361     }
 362
 363     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
 364     if (r < 0) {
 365         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
 366         fflush(stderr);
 367     }
 368     assert(r >= 0);
 369
 370     assert(vhost_net_set_vnet_endian(dev, ncs[0].peer, false) >= 0);
 371 }
 372
 373 void vhost_net_cleanup(struct vhost_net *net)
 374 {
 375     vhost_dev_cleanup(&net->dev);
 376     g_free(net);
 377 }
 378
 379 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
 380 {
 381     const VhostOps *vhost_ops = net->dev.vhost_ops;
 382     int r = -1;
 383
 384     if (vhost_ops->vhost_migration_done) {
 385         r = vhost_ops->vhost_migration_done(&net->dev, mac_addr);
 386     }
 387
 388     return r;
 389 }
 390
 391 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 392 {
 393     return vhost_virtqueue_pending(&net->dev, idx);
 394 }
 395
 396 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 397                               int idx, bool mask)
 398 {
 399     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
 400 }
 401
 402 VHostNetState *get_vhost_net(NetClientState *nc)
 403 {
 404     VHostNetState *vhost_net = 0;
 405
 406     if (!nc) {
 407         return 0;
 408     }
 409
 410     switch (nc->info->type) {
 411     case NET_CLIENT_OPTIONS_KIND_TAP:
 412         vhost_net = tap_get_vhost_net(nc);
 413         break;
 414     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
 415         vhost_net = vhost_user_get_vhost_net(nc);
 416         break;
 417     default:
 418         break;
 419     }
 420
 421     return vhost_net;
 422 }
 423
 424 int vhost_set_vring_enable(NetClientState *nc, int enable)
 425 {
 426     VHostNetState *net = get_vhost_net(nc);
 427     const VhostOps *vhost_ops = net->dev.vhost_ops;
 428
 429     if (vhost_ops->vhost_set_vring_enable) {
 430         return vhost_ops->vhost_set_vring_enable(&net->dev, enable);
 431     }
 432
 433     return 0;
 434 }
 435
 436 #else
 437 uint64_t vhost_net_get_max_queues(VHostNetState *net)
 438 {
 439     return 1;
 440 }
 441
 442 struct vhost_net *vhost_net_init(VhostNetOptions *options)
 443 {
 444     error_report("vhost-net support is not compiled in");
 445     return NULL;
 446 }
 447
 448 int vhost_net_start(VirtIODevice *dev,
 449                     NetClientState *ncs,
 450                     int total_queues)
 451 {
 452     return -ENOSYS;
 453 }
 454 void vhost_net_stop(VirtIODevice *dev,
 455                     NetClientState *ncs,
 456                     int total_queues)
 457 {
 458 }
 459
 460 void vhost_net_cleanup(struct vhost_net *net)
 461 {
 462 }
 463
 464 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
 465 {
 466     return features;
 467 }
 468 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
 469 {
 470 }
 471
 472 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 473 {
 474     return false;
 475 }
 476
 477 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 478                               int idx, bool mask)
 479 {
 480 }
 481
 482 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
 483 {
 484     return -1;
 485 }
 486
 487 VHostNetState *get_vhost_net(NetClientState *nc)
 488 {
 489     return 0;
 490 }
 491
 492 int vhost_set_vring_enable(NetClientState *nc, int enable)
 493 {
 494     return 0;
 495 }
 496 #endif