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     VIRTIO_NET_F_STATUS,
  81     VIRTIO_NET_F_CTRL_VQ,
  82     VIRTIO_NET_F_CTRL_RX,
  83     VIRTIO_NET_F_CTRL_VLAN,
  84     VIRTIO_NET_F_CTRL_RX_EXTRA,
  85     VIRTIO_NET_F_CTRL_MAC_ADDR,
  86     VIRTIO_NET_F_CTRL_GUEST_OFFLOADS,
  87
  88     VIRTIO_NET_F_MQ,
  89
  90     VHOST_INVALID_FEATURE_BIT
  91 };
  92
  93 static const int *vhost_net_get_feature_bits(struct vhost_net *net)
  94 {
  95     const int *feature_bits = 0;
  96
  97     switch (net->nc->info->type) {
  98     case NET_CLIENT_OPTIONS_KIND_TAP:
  99         feature_bits = kernel_feature_bits;
 100         break;
 101     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
 102         feature_bits = user_feature_bits;
 103         break;
 104     default:
 105         error_report("Feature bits not defined for this type: %d",
 106                 net->nc->info->type);
 107         break;
 108     }
 109
 110     return feature_bits;
 111 }
 112
 113 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
 114 {
 115     return vhost_get_features(&net->dev, vhost_net_get_feature_bits(net),
 116             features);
 117 }
 118
 119 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
 120 {
 121     net->dev.acked_features = net->dev.backend_features;
 122     vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
 123 }
 124
 125 static int vhost_net_get_fd(NetClientState *backend)
 126 {
 127     switch (backend->info->type) {
 128     case NET_CLIENT_OPTIONS_KIND_TAP:
 129         return tap_get_fd(backend);
 130     default:
 131         fprintf(stderr, "vhost-net requires tap backend\n");
 132         return -EBADFD;
 133     }
 134 }
 135
 136 struct vhost_net *vhost_net_init(VhostNetOptions *options)
 137 {
 138     int r;
 139     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
 140     struct vhost_net *net = g_malloc(sizeof *net);
 141
 142     if (!options->net_backend) {
 143         fprintf(stderr, "vhost-net requires net backend to be setup\n");
 144         goto fail;
 145     }
 146
 147     if (backend_kernel) {
 148         r = vhost_net_get_fd(options->net_backend);
 149         if (r < 0) {
 150             goto fail;
 151         }
 152         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
 153             ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
 154         net->backend = r;
 155     } else {
 156         net->dev.backend_features = 0;
 157         net->backend = -1;
 158     }
 159     net->nc = options->net_backend;
 160
 161     net->dev.nvqs = 2;
 162     net->dev.vqs = net->vqs;
 163     net->dev.vq_index = net->nc->queue_index;
 164
 165     r = vhost_dev_init(&net->dev, options->opaque,
 166                        options->backend_type);
 167     if (r < 0) {
 168         goto fail;
 169     }
 170     if (backend_kernel) {
 171         if (!qemu_has_vnet_hdr_len(options->net_backend,
 172                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
 173             net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
 174         }
 175         if (~net->dev.features & net->dev.backend_features) {
 176             fprintf(stderr, "vhost lacks feature mask %" PRIu64
 177                    " for backend\n",
 178                    (uint64_t)(~net->dev.features & net->dev.backend_features));
 179             vhost_dev_cleanup(&net->dev);
 180             goto fail;
 181         }
 182     }
 183     /* Set sane init value. Override when guest acks. */
 184     vhost_net_ack_features(net, 0);
 185     return net;
 186 fail:
 187     g_free(net);
 188     return NULL;
 189 }
 190
 191 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
 192 {
 193     net->dev.vq_index = vq_index;
 194 }
 195
 196 static int vhost_net_set_vnet_endian(VirtIODevice *dev, NetClientState *peer,
 197                                      bool set)
 198 {
 199     int r = 0;
 200
 201     if (virtio_has_feature(dev, VIRTIO_F_VERSION_1) ||
 202         (virtio_legacy_is_cross_endian(dev) && !virtio_is_big_endian(dev))) {
 203         r = qemu_set_vnet_le(peer, set);
 204         if (r) {
 205             error_report("backend does not support LE vnet headers");
 206         }
 207     } else if (virtio_legacy_is_cross_endian(dev)) {
 208         r = qemu_set_vnet_be(peer, set);
 209         if (r) {
 210             error_report("backend does not support BE vnet headers");
 211         }
 212     }
 213
 214     return r;
 215 }
 216
 217 static int vhost_net_start_one(struct vhost_net *net,
 218                                VirtIODevice *dev)
 219 {
 220     struct vhost_vring_file file = { };
 221     int r;
 222
 223     net->dev.nvqs = 2;
 224     net->dev.vqs = net->vqs;
 225
 226     r = vhost_dev_enable_notifiers(&net->dev, dev);
 227     if (r < 0) {
 228         goto fail_notifiers;
 229     }
 230
 231     r = vhost_dev_start(&net->dev, dev);
 232     if (r < 0) {
 233         goto fail_start;
 234     }
 235
 236     if (net->nc->info->poll) {
 237         net->nc->info->poll(net->nc, false);
 238     }
 239
 240     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
 241         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
 242         file.fd = net->backend;
 243         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
 244             const VhostOps *vhost_ops = net->dev.vhost_ops;
 245             r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
 246                                       &file);
 247             if (r < 0) {
 248                 r = -errno;
 249                 goto fail;
 250             }
 251         }
 252     }
 253     return 0;
 254 fail:
 255     file.fd = -1;
 256     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
 257         while (file.index-- > 0) {
 258             const VhostOps *vhost_ops = net->dev.vhost_ops;
 259             int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
 260                                           &file);
 261             assert(r >= 0);
 262         }
 263     }
 264     if (net->nc->info->poll) {
 265         net->nc->info->poll(net->nc, true);
 266     }
 267     vhost_dev_stop(&net->dev, dev);
 268 fail_start:
 269     vhost_dev_disable_notifiers(&net->dev, dev);
 270 fail_notifiers:
 271     return r;
 272 }
 273
 274 static void vhost_net_stop_one(struct vhost_net *net,
 275                                VirtIODevice *dev)
 276 {
 277     struct vhost_vring_file file = { .fd = -1 };
 278
 279     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
 280         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
 281             const VhostOps *vhost_ops = net->dev.vhost_ops;
 282             int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
 283                                           &file);
 284             assert(r >= 0);
 285         }
 286     } else if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
 287         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
 288             const VhostOps *vhost_ops = net->dev.vhost_ops;
 289             int r = vhost_ops->vhost_call(&net->dev, VHOST_RESET_OWNER,
 290                                           &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         r = -ENOSYS;
 312         goto err;
 313     }
 314
 315     r = vhost_net_set_vnet_endian(dev, ncs[0].peer, true);
 316     if (r < 0) {
 317         goto err;
 318     }
 319
 320     for (i = 0; i < total_queues; i++) {
 321         vhost_net_set_vq_index(get_vhost_net(ncs[i].peer), i * 2);
 322     }
 323
 324     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
 325     if (r < 0) {
 326         error_report("Error binding guest notifier: %d", -r);
 327         goto err_endian;
 328     }
 329
 330     for (i = 0; i < total_queues; i++) {
 331         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
 332
 333         if (r < 0) {
 334             goto err_start;
 335         }
 336     }
 337
 338     return 0;
 339
 340 err_start:
 341     while (--i >= 0) {
 342         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
 343     }
 344     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
 345     if (e < 0) {
 346         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
 347         fflush(stderr);
 348     }
 349 err_endian:
 350     vhost_net_set_vnet_endian(dev, ncs[0].peer, false);
 351 err:
 352     return r;
 353 }
 354
 355 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
 356                     int total_queues)
 357 {
 358     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
 359     VirtioBusState *vbus = VIRTIO_BUS(qbus);
 360     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
 361     int i, r;
 362
 363     for (i = 0; i < total_queues; i++) {
 364         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
 365     }
 366
 367     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
 368     if (r < 0) {
 369         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
 370         fflush(stderr);
 371     }
 372     assert(r >= 0);
 373
 374     assert(vhost_net_set_vnet_endian(dev, ncs[0].peer, false) >= 0);
 375 }
 376
 377 void vhost_net_cleanup(struct vhost_net *net)
 378 {
 379     vhost_dev_cleanup(&net->dev);
 380     g_free(net);
 381 }
 382
 383 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 384 {
 385     return vhost_virtqueue_pending(&net->dev, idx);
 386 }
 387
 388 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 389                               int idx, bool mask)
 390 {
 391     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
 392 }
 393
 394 VHostNetState *get_vhost_net(NetClientState *nc)
 395 {
 396     VHostNetState *vhost_net = 0;
 397
 398     if (!nc) {
 399         return 0;
 400     }
 401
 402     switch (nc->info->type) {
 403     case NET_CLIENT_OPTIONS_KIND_TAP:
 404         vhost_net = tap_get_vhost_net(nc);
 405         break;
 406     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
 407         vhost_net = vhost_user_get_vhost_net(nc);
 408         break;
 409     default:
 410         break;
 411     }
 412
 413     return vhost_net;
 414 }
 415 #else
 416 struct vhost_net *vhost_net_init(VhostNetOptions *options)
 417 {
 418     error_report("vhost-net support is not compiled in");
 419     return NULL;
 420 }
 421
 422 int vhost_net_start(VirtIODevice *dev,
 423                     NetClientState *ncs,
 424                     int total_queues)
 425 {
 426     return -ENOSYS;
 427 }
 428 void vhost_net_stop(VirtIODevice *dev,
 429                     NetClientState *ncs,
 430                     int total_queues)
 431 {
 432 }
 433
 434 void vhost_net_cleanup(struct vhost_net *net)
 435 {
 436 }
 437
 438 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
 439 {
 440     return features;
 441 }
 442 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
 443 {
 444 }
 445
 446 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 447 {
 448     return false;
 449 }
 450
 451 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 452                               int idx, bool mask)
 453 {
 454 }
 455
 456 VHostNetState *get_vhost_net(NetClientState *nc)
 457 {
 458     return 0;
 459 }
 460 #endif