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 "standard-headers/linux/vhost_types.h"
  22 #include "hw/virtio/virtio-net.h"
  23 #include "net/vhost_net.h"
  24 #include "qemu/error-report.h"
  25
  26
  27 #include <sys/socket.h>
  28 #include <net/if.h>
  29 #include <netinet/in.h>
  30
  31
  32 #include "standard-headers/linux/virtio_ring.h"
  33 #include "hw/virtio/vhost.h"
  34 #include "hw/virtio/virtio-bus.h"
  35
  36 struct vhost_net {
  37     struct vhost_dev dev;
  38     struct vhost_virtqueue vqs[2];
  39     int backend;
  40     NetClientState *nc;
  41 };
  42
  43 /* Features supported by host kernel. */
  44 static const int kernel_feature_bits[] = {
  45     VIRTIO_F_NOTIFY_ON_EMPTY,
  46     VIRTIO_RING_F_INDIRECT_DESC,
  47     VIRTIO_RING_F_EVENT_IDX,
  48     VIRTIO_NET_F_MRG_RXBUF,
  49     VIRTIO_F_VERSION_1,
  50     VIRTIO_NET_F_MTU,
  51     VIRTIO_F_IOMMU_PLATFORM,
  52     VHOST_INVALID_FEATURE_BIT
  53 };
  54
  55 /* Features supported by others. */
  56 static const int user_feature_bits[] = {
  57     VIRTIO_F_NOTIFY_ON_EMPTY,
  58     VIRTIO_RING_F_INDIRECT_DESC,
  59     VIRTIO_RING_F_EVENT_IDX,
  60
  61     VIRTIO_F_ANY_LAYOUT,
  62     VIRTIO_F_VERSION_1,
  63     VIRTIO_NET_F_CSUM,
  64     VIRTIO_NET_F_GUEST_CSUM,
  65     VIRTIO_NET_F_GSO,
  66     VIRTIO_NET_F_GUEST_TSO4,
  67     VIRTIO_NET_F_GUEST_TSO6,
  68     VIRTIO_NET_F_GUEST_ECN,
  69     VIRTIO_NET_F_GUEST_UFO,
  70     VIRTIO_NET_F_HOST_TSO4,
  71     VIRTIO_NET_F_HOST_TSO6,
  72     VIRTIO_NET_F_HOST_ECN,
  73     VIRTIO_NET_F_HOST_UFO,
  74     VIRTIO_NET_F_MRG_RXBUF,
  75     VIRTIO_NET_F_MTU,
  76     VIRTIO_F_IOMMU_PLATFORM,
  77
  78     /* This bit implies RARP isn't sent by QEMU out of band */
  79     VIRTIO_NET_F_GUEST_ANNOUNCE,
  80
  81     VIRTIO_NET_F_MQ,
  82
  83     VHOST_INVALID_FEATURE_BIT
  84 };
  85
  86 static const int *vhost_net_get_feature_bits(struct vhost_net *net)
  87 {
  88     const int *feature_bits = 0;
  89
  90     switch (net->nc->info->type) {
  91     case NET_CLIENT_DRIVER_TAP:
  92         feature_bits = kernel_feature_bits;
  93         break;
  94     case NET_CLIENT_DRIVER_VHOST_USER:
  95         feature_bits = user_feature_bits;
  96         break;
  97     default:
  98         error_report("Feature bits not defined for this type: %d",
  99                 net->nc->info->type);
 100         break;
 101     }
 102
 103     return feature_bits;
 104 }
 105
 106 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
 107 {
 108     return vhost_get_features(&net->dev, vhost_net_get_feature_bits(net),
 109             features);
 110 }
 111
 112 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
 113 {
 114     net->dev.acked_features = net->dev.backend_features;
 115     vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
 116 }
 117
 118 uint64_t vhost_net_get_max_queues(VHostNetState *net)
 119 {
 120     return net->dev.max_queues;
 121 }
 122
 123 uint64_t vhost_net_get_acked_features(VHostNetState *net)
 124 {
 125     return net->dev.acked_features;
 126 }
 127
 128 static int vhost_net_get_fd(NetClientState *backend)
 129 {
 130     switch (backend->info->type) {
 131     case NET_CLIENT_DRIVER_TAP:
 132         return tap_get_fd(backend);
 133     default:
 134         fprintf(stderr, "vhost-net requires tap backend\n");
 135         return -ENOSYS;
 136     }
 137 }
 138
 139 struct vhost_net *vhost_net_init(VhostNetOptions *options)
 140 {
 141     int r;
 142     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
 143     struct vhost_net *net = g_new0(struct vhost_net, 1);
 144     uint64_t features = 0;
 145
 146     if (!options->net_backend) {
 147         fprintf(stderr, "vhost-net requires net backend to be setup\n");
 148         goto fail;
 149     }
 150     net->nc = options->net_backend;
 151
 152     net->dev.max_queues = 1;
 153     net->dev.nvqs = 2;
 154     net->dev.vqs = net->vqs;
 155
 156     if (backend_kernel) {
 157         r = vhost_net_get_fd(options->net_backend);
 158         if (r < 0) {
 159             goto fail;
 160         }
 161         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
 162             ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
 163         net->backend = r;
 164         net->dev.protocol_features = 0;
 165     } else {
 166         net->dev.backend_features = 0;
 167         net->dev.protocol_features = 0;
 168         net->backend = -1;
 169
 170         /* vhost-user needs vq_index to initiate a specific queue pair */
 171         net->dev.vq_index = net->nc->queue_index * net->dev.nvqs;
 172     }
 173
 174     r = vhost_dev_init(&net->dev, options->opaque,
 175                        options->backend_type, options->busyloop_timeout);
 176     if (r < 0) {
 177         goto fail;
 178     }
 179     if (backend_kernel) {
 180         if (!qemu_has_vnet_hdr_len(options->net_backend,
 181                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
 182             net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
 183         }
 184         if (~net->dev.features & net->dev.backend_features) {
 185             fprintf(stderr, "vhost lacks feature mask %" PRIu64
 186                    " for backend\n",
 187                    (uint64_t)(~net->dev.features & net->dev.backend_features));
 188             goto fail;
 189         }
 190     }
 191
 192     /* Set sane init value. Override when guest acks. */
 193 #ifdef CONFIG_VHOST_NET_USER
 194     if (net->nc->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
 195         features = vhost_user_get_acked_features(net->nc);
 196         if (~net->dev.features & features) {
 197             fprintf(stderr, "vhost lacks feature mask %" PRIu64
 198                     " for backend\n",
 199                     (uint64_t)(~net->dev.features & features));
 200             goto fail;
 201         }
 202     }
 203 #endif
 204
 205     vhost_net_ack_features(net, features);
 206
 207     return net;
 208
 209 fail:
 210     vhost_dev_cleanup(&net->dev);
 211     g_free(net);
 212     return NULL;
 213 }
 214
 215 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
 216 {
 217     net->dev.vq_index = vq_index;
 218 }
 219
 220 static int vhost_net_start_one(struct vhost_net *net,
 221                                VirtIODevice *dev)
 222 {
 223     struct vhost_vring_file file = { };
 224     int r;
 225
 226     net->dev.nvqs = 2;
 227     net->dev.vqs = net->vqs;
 228
 229     r = vhost_dev_enable_notifiers(&net->dev, dev);
 230     if (r < 0) {
 231         goto fail_notifiers;
 232     }
 233
 234     r = vhost_dev_start(&net->dev, dev);
 235     if (r < 0) {
 236         goto fail_start;
 237     }
 238
 239     if (net->nc->info->poll) {
 240         net->nc->info->poll(net->nc, false);
 241     }
 242
 243     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
 244         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
 245         file.fd = net->backend;
 246         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
 247             if (!virtio_queue_enabled(dev, net->dev.vq_index +
 248                                       file.index)) {
 249                 /* Queue might not be ready for start */
 250                 continue;
 251             }
 252             r = vhost_net_set_backend(&net->dev, &file);
 253             if (r < 0) {
 254                 r = -errno;
 255                 goto fail;
 256             }
 257         }
 258     }
 259     return 0;
 260 fail:
 261     file.fd = -1;
 262     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
 263         while (file.index-- > 0) {
 264             if (!virtio_queue_enabled(dev, net->dev.vq_index +
 265                                       file.index)) {
 266                 /* Queue might not be ready for start */
 267                 continue;
 268             }
 269             int r = vhost_net_set_backend(&net->dev, &file);
 270             assert(r >= 0);
 271         }
 272     }
 273     if (net->nc->info->poll) {
 274         net->nc->info->poll(net->nc, true);
 275     }
 276     vhost_dev_stop(&net->dev, dev);
 277 fail_start:
 278     vhost_dev_disable_notifiers(&net->dev, dev);
 279 fail_notifiers:
 280     return r;
 281 }
 282
 283 static void vhost_net_stop_one(struct vhost_net *net,
 284                                VirtIODevice *dev)
 285 {
 286     struct vhost_vring_file file = { .fd = -1 };
 287
 288     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
 289         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
 290             int r = vhost_net_set_backend(&net->dev, &file);
 291             assert(r >= 0);
 292         }
 293     }
 294     if (net->nc->info->poll) {
 295         net->nc->info->poll(net->nc, true);
 296     }
 297     vhost_dev_stop(&net->dev, dev);
 298     vhost_dev_disable_notifiers(&net->dev, dev);
 299 }
 300
 301 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
 302                     int total_queues)
 303 {
 304     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
 305     VirtioBusState *vbus = VIRTIO_BUS(qbus);
 306     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
 307     int r, e, i;
 308
 309     if (!k->set_guest_notifiers) {
 310         error_report("binding does not support guest notifiers");
 311         return -ENOSYS;
 312     }
 313
 314     for (i = 0; i < total_queues; i++) {
 315         struct vhost_net *net;
 316
 317         net = get_vhost_net(ncs[i].peer);
 318         vhost_net_set_vq_index(net, i * 2);
 319
 320         /* Suppress the masking guest notifiers on vhost user
 321          * because vhost user doesn't interrupt masking/unmasking
 322          * properly.
 323          */
 324         if (net->nc->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
 325             dev->use_guest_notifier_mask = false;
 326         }
 327      }
 328
 329     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
 330     if (r < 0) {
 331         error_report("Error binding guest notifier: %d", -r);
 332         goto err;
 333     }
 334
 335     for (i = 0; i < total_queues; i++) {
 336         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
 337
 338         if (r < 0) {
 339             goto err_start;
 340         }
 341
 342         if (ncs[i].peer->vring_enable) {
 343             /* restore vring enable state */
 344             r = vhost_set_vring_enable(ncs[i].peer, ncs[i].peer->vring_enable);
 345
 346             if (r < 0) {
 347                 goto err_start;
 348             }
 349         }
 350     }
 351
 352     return 0;
 353
 354 err_start:
 355     while (--i >= 0) {
 356         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
 357     }
 358     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
 359     if (e < 0) {
 360         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
 361         fflush(stderr);
 362     }
 363 err:
 364     return r;
 365 }
 366
 367 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
 368                     int total_queues)
 369 {
 370     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
 371     VirtioBusState *vbus = VIRTIO_BUS(qbus);
 372     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
 373     int i, r;
 374
 375     for (i = 0; i < total_queues; i++) {
 376         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
 377     }
 378
 379     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
 380     if (r < 0) {
 381         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
 382         fflush(stderr);
 383     }
 384     assert(r >= 0);
 385 }
 386
 387 void vhost_net_cleanup(struct vhost_net *net)
 388 {
 389     vhost_dev_cleanup(&net->dev);
 390 }
 391
 392 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
 393 {
 394     const VhostOps *vhost_ops = net->dev.vhost_ops;
 395
 396     assert(vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
 397     assert(vhost_ops->vhost_migration_done);
 398
 399     return vhost_ops->vhost_migration_done(&net->dev, mac_addr);
 400 }
 401
 402 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 403 {
 404     return vhost_virtqueue_pending(&net->dev, idx);
 405 }
 406
 407 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 408                               int idx, bool mask)
 409 {
 410     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
 411 }
 412
 413 VHostNetState *get_vhost_net(NetClientState *nc)
 414 {
 415     VHostNetState *vhost_net = 0;
 416
 417     if (!nc) {
 418         return 0;
 419     }
 420
 421     switch (nc->info->type) {
 422     case NET_CLIENT_DRIVER_TAP:
 423         vhost_net = tap_get_vhost_net(nc);
 424         break;
 425 #ifdef CONFIG_VHOST_NET_USER
 426     case NET_CLIENT_DRIVER_VHOST_USER:
 427         vhost_net = vhost_user_get_vhost_net(nc);
 428         assert(vhost_net);
 429         break;
 430 #endif
 431     default:
 432         break;
 433     }
 434
 435     return vhost_net;
 436 }
 437
 438 int vhost_set_vring_enable(NetClientState *nc, int enable)
 439 {
 440     VHostNetState *net = get_vhost_net(nc);
 441     const VhostOps *vhost_ops = net->dev.vhost_ops;
 442
 443     nc->vring_enable = enable;
 444
 445     if (vhost_ops && vhost_ops->vhost_set_vring_enable) {
 446         return vhost_ops->vhost_set_vring_enable(&net->dev, enable);
 447     }
 448
 449     return 0;
 450 }
 451
 452 int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
 453 {
 454     const VhostOps *vhost_ops = net->dev.vhost_ops;
 455
 456     if (!vhost_ops->vhost_net_set_mtu) {
 457         return 0;
 458     }
 459
 460     return vhost_ops->vhost_net_set_mtu(&net->dev, mtu);
 461 }