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 <linux/virtio_ring.h>
  32 #include <netpacket/packet.h>
  33 #include <net/ethernet.h>
  34 #include <net/if.h>
  35 #include <netinet/in.h>
  36
  37 #include <stdio.h>
  38
  39 #include "hw/virtio/vhost.h"
  40 #include "hw/virtio/virtio-bus.h"
  41
  42 struct vhost_net {
  43     struct vhost_dev dev;
  44     struct vhost_virtqueue vqs[2];
  45     int backend;
  46     NetClientState *nc;
  47 };
  48
  49 /* Features supported by host kernel. */
  50 static const int kernel_feature_bits[] = {
  51     VIRTIO_F_NOTIFY_ON_EMPTY,
  52     VIRTIO_RING_F_INDIRECT_DESC,
  53     VIRTIO_RING_F_EVENT_IDX,
  54     VIRTIO_NET_F_MRG_RXBUF,
  55     VHOST_INVALID_FEATURE_BIT
  56 };
  57
  58 /* Features supported by others. */
  59 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_NET_F_CSUM,
  66     VIRTIO_NET_F_GUEST_CSUM,
  67     VIRTIO_NET_F_GSO,
  68     VIRTIO_NET_F_GUEST_TSO4,
  69     VIRTIO_NET_F_GUEST_TSO6,
  70     VIRTIO_NET_F_GUEST_ECN,
  71     VIRTIO_NET_F_GUEST_UFO,
  72     VIRTIO_NET_F_HOST_TSO4,
  73     VIRTIO_NET_F_HOST_TSO6,
  74     VIRTIO_NET_F_HOST_ECN,
  75     VIRTIO_NET_F_HOST_UFO,
  76     VIRTIO_NET_F_MRG_RXBUF,
  77     VIRTIO_NET_F_STATUS,
  78     VIRTIO_NET_F_CTRL_VQ,
  79     VIRTIO_NET_F_CTRL_RX,
  80     VIRTIO_NET_F_CTRL_VLAN,
  81     VIRTIO_NET_F_CTRL_RX_EXTRA,
  82     VIRTIO_NET_F_CTRL_MAC_ADDR,
  83     VIRTIO_NET_F_CTRL_GUEST_OFFLOADS,
  84
  85     VIRTIO_NET_F_MQ,
  86
  87     VHOST_INVALID_FEATURE_BIT
  88 };
  89
  90 static const int *vhost_net_get_feature_bits(struct vhost_net *net)
  91 {
  92     const int *feature_bits = 0;
  93
  94     switch (net->nc->info->type) {
  95     case NET_CLIENT_OPTIONS_KIND_TAP:
  96         feature_bits = kernel_feature_bits;
  97         break;
  98     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
  99         feature_bits = user_feature_bits;
 100         break;
 101     default:
 102         error_report("Feature bits not defined for this type: %d",
 103                 net->nc->info->type);
 104         break;
 105     }
 106
 107     return feature_bits;
 108 }
 109
 110 unsigned vhost_net_get_features(struct vhost_net *net, unsigned features)
 111 {
 112     return vhost_get_features(&net->dev, vhost_net_get_feature_bits(net),
 113             features);
 114 }
 115
 116 void vhost_net_ack_features(struct vhost_net *net, unsigned features)
 117 {
 118     vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
 119 }
 120
 121 static int vhost_net_get_fd(NetClientState *backend)
 122 {
 123     switch (backend->info->type) {
 124     case NET_CLIENT_OPTIONS_KIND_TAP:
 125         return tap_get_fd(backend);
 126     default:
 127         fprintf(stderr, "vhost-net requires tap backend\n");
 128         return -EBADFD;
 129     }
 130 }
 131
 132 struct vhost_net *vhost_net_init(VhostNetOptions *options)
 133 {
 134     int r;
 135     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
 136     struct vhost_net *net = g_malloc(sizeof *net);
 137
 138     if (!options->net_backend) {
 139         fprintf(stderr, "vhost-net requires net backend to be setup\n");
 140         goto fail;
 141     }
 142
 143     if (backend_kernel) {
 144         r = vhost_net_get_fd(options->net_backend);
 145         if (r < 0) {
 146             goto fail;
 147         }
 148         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
 149             ? 0 : (1 << VHOST_NET_F_VIRTIO_NET_HDR);
 150         net->backend = r;
 151     } else {
 152         net->dev.backend_features = 0;
 153         net->backend = -1;
 154     }
 155     net->nc = options->net_backend;
 156
 157     net->dev.nvqs = 2;
 158     net->dev.vqs = net->vqs;
 159
 160     r = vhost_dev_init(&net->dev, options->opaque,
 161                        options->backend_type, options->force);
 162     if (r < 0) {
 163         goto fail;
 164     }
 165     if (!qemu_has_vnet_hdr_len(options->net_backend,
 166                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
 167         net->dev.features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF);
 168     }
 169     if (backend_kernel) {
 170         if (~net->dev.features & net->dev.backend_features) {
 171             fprintf(stderr, "vhost lacks feature mask %" PRIu64
 172                    " for backend\n",
 173                    (uint64_t)(~net->dev.features & net->dev.backend_features));
 174             vhost_dev_cleanup(&net->dev);
 175             goto fail;
 176         }
 177     }
 178     /* Set sane init value. Override when guest acks. */
 179     vhost_net_ack_features(net, 0);
 180     return net;
 181 fail:
 182     g_free(net);
 183     return NULL;
 184 }
 185
 186 bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
 187 {
 188     return vhost_dev_query(&net->dev, dev);
 189 }
 190
 191 static int vhost_net_start_one(struct vhost_net *net,
 192                                VirtIODevice *dev,
 193                                int vq_index)
 194 {
 195     struct vhost_vring_file file = { };
 196     int r;
 197
 198     if (net->dev.started) {
 199         return 0;
 200     }
 201
 202     net->dev.nvqs = 2;
 203     net->dev.vqs = net->vqs;
 204     net->dev.vq_index = vq_index;
 205
 206     r = vhost_dev_enable_notifiers(&net->dev, dev);
 207     if (r < 0) {
 208         goto fail_notifiers;
 209     }
 210
 211     r = vhost_dev_start(&net->dev, dev);
 212     if (r < 0) {
 213         goto fail_start;
 214     }
 215
 216     if (net->nc->info->poll) {
 217         net->nc->info->poll(net->nc, false);
 218     }
 219
 220     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
 221         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
 222         file.fd = net->backend;
 223         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
 224             const VhostOps *vhost_ops = net->dev.vhost_ops;
 225             r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
 226                                       &file);
 227             if (r < 0) {
 228                 r = -errno;
 229                 goto fail;
 230             }
 231         }
 232     }
 233     return 0;
 234 fail:
 235     file.fd = -1;
 236     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
 237         while (file.index-- > 0) {
 238             const VhostOps *vhost_ops = net->dev.vhost_ops;
 239             int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
 240                                           &file);
 241             assert(r >= 0);
 242         }
 243     }
 244     if (net->nc->info->poll) {
 245         net->nc->info->poll(net->nc, true);
 246     }
 247     vhost_dev_stop(&net->dev, dev);
 248 fail_start:
 249     vhost_dev_disable_notifiers(&net->dev, dev);
 250 fail_notifiers:
 251     return r;
 252 }
 253
 254 static void vhost_net_stop_one(struct vhost_net *net,
 255                                VirtIODevice *dev)
 256 {
 257     struct vhost_vring_file file = { .fd = -1 };
 258
 259     if (!net->dev.started) {
 260         return;
 261     }
 262
 263     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
 264         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
 265             const VhostOps *vhost_ops = net->dev.vhost_ops;
 266             int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
 267                                           &file);
 268             assert(r >= 0);
 269         }
 270     }
 271     if (net->nc->info->poll) {
 272         net->nc->info->poll(net->nc, true);
 273     }
 274     vhost_dev_stop(&net->dev, dev);
 275     vhost_dev_disable_notifiers(&net->dev, dev);
 276 }
 277
 278 static bool vhost_net_device_endian_ok(VirtIODevice *vdev)
 279 {
 280 #ifdef TARGET_IS_BIENDIAN
 281 #ifdef HOST_WORDS_BIGENDIAN
 282     return virtio_is_big_endian(vdev);
 283 #else
 284     return !virtio_is_big_endian(vdev);
 285 #endif
 286 #else
 287     return true;
 288 #endif
 289 }
 290
 291 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
 292                     int total_queues)
 293 {
 294     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
 295     VirtioBusState *vbus = VIRTIO_BUS(qbus);
 296     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
 297     int r, i = 0;
 298
 299     if (!vhost_net_device_endian_ok(dev)) {
 300         error_report("vhost-net does not support cross-endian");
 301         r = -ENOSYS;
 302         goto err;
 303     }
 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     for (i = 0; i < total_queues; i++) {
 312         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev, i * 2);
 313
 314         if (r < 0) {
 315             goto err;
 316         }
 317     }
 318
 319     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
 320     if (r < 0) {
 321         error_report("Error binding guest notifier: %d", -r);
 322         goto err;
 323     }
 324
 325     return 0;
 326
 327 err:
 328     while (--i >= 0) {
 329         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
 330     }
 331     return r;
 332 }
 333
 334 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
 335                     int total_queues)
 336 {
 337     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
 338     VirtioBusState *vbus = VIRTIO_BUS(qbus);
 339     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
 340     int i, r;
 341
 342     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
 343     if (r < 0) {
 344         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
 345         fflush(stderr);
 346     }
 347     assert(r >= 0);
 348
 349     for (i = 0; i < total_queues; i++) {
 350         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
 351     }
 352 }
 353
 354 void vhost_net_cleanup(struct vhost_net *net)
 355 {
 356     vhost_dev_cleanup(&net->dev);
 357     g_free(net);
 358 }
 359
 360 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 361 {
 362     return vhost_virtqueue_pending(&net->dev, idx);
 363 }
 364
 365 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 366                               int idx, bool mask)
 367 {
 368     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
 369 }
 370
 371 VHostNetState *get_vhost_net(NetClientState *nc)
 372 {
 373     VHostNetState *vhost_net = 0;
 374
 375     if (!nc) {
 376         return 0;
 377     }
 378
 379     switch (nc->info->type) {
 380     case NET_CLIENT_OPTIONS_KIND_TAP:
 381         vhost_net = tap_get_vhost_net(nc);
 382         break;
 383     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
 384         vhost_net = vhost_user_get_vhost_net(nc);
 385         break;
 386     default:
 387         break;
 388     }
 389
 390     return vhost_net;
 391 }
 392 #else
 393 struct vhost_net *vhost_net_init(VhostNetOptions *options)
 394 {
 395     error_report("vhost-net support is not compiled in");
 396     return NULL;
 397 }
 398
 399 bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
 400 {
 401     return false;
 402 }
 403
 404 int vhost_net_start(VirtIODevice *dev,
 405                     NetClientState *ncs,
 406                     int total_queues)
 407 {
 408     return -ENOSYS;
 409 }
 410 void vhost_net_stop(VirtIODevice *dev,
 411                     NetClientState *ncs,
 412                     int total_queues)
 413 {
 414 }
 415
 416 void vhost_net_cleanup(struct vhost_net *net)
 417 {
 418 }
 419
 420 unsigned vhost_net_get_features(struct vhost_net *net, unsigned features)
 421 {
 422     return features;
 423 }
 424 void vhost_net_ack_features(struct vhost_net *net, unsigned features)
 425 {
 426 }
 427
 428 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 429 {
 430     return false;
 431 }
 432
 433 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 434                               int idx, bool mask)
 435 {
 436 }
 437
 438 VHostNetState *get_vhost_net(NetClientState *nc)
 439 {
 440     return 0;
 441 }
 442 #endif