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