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     net->dev.acked_features = net->dev.backend_features;
 119     vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
 120 }
 121
 122 static int vhost_net_get_fd(NetClientState *backend)
 123 {
 124     switch (backend->info->type) {
 125     case NET_CLIENT_OPTIONS_KIND_TAP:
 126         return tap_get_fd(backend);
 127     default:
 128         fprintf(stderr, "vhost-net requires tap backend\n");
 129         return -EBADFD;
 130     }
 131 }
 132
 133 struct vhost_net *vhost_net_init(VhostNetOptions *options)
 134 {
 135     int r;
 136     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
 137     struct vhost_net *net = g_malloc(sizeof *net);
 138
 139     if (!options->net_backend) {
 140         fprintf(stderr, "vhost-net requires net backend to be setup\n");
 141         goto fail;
 142     }
 143
 144     if (backend_kernel) {
 145         r = vhost_net_get_fd(options->net_backend);
 146         if (r < 0) {
 147             goto fail;
 148         }
 149         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
 150             ? 0 : (1 << VHOST_NET_F_VIRTIO_NET_HDR);
 151         net->backend = r;
 152     } else {
 153         net->dev.backend_features = 0;
 154         net->backend = -1;
 155     }
 156     net->nc = options->net_backend;
 157
 158     net->dev.nvqs = 2;
 159     net->dev.vqs = net->vqs;
 160
 161     r = vhost_dev_init(&net->dev, options->opaque,
 162                        options->backend_type, options->force);
 163     if (r < 0) {
 164         goto fail;
 165     }
 166     if (backend_kernel) {
 167         if (!qemu_has_vnet_hdr_len(options->net_backend,
 168                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
 169             net->dev.features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF);
 170         }
 171         if (~net->dev.features & net->dev.backend_features) {
 172             fprintf(stderr, "vhost lacks feature mask %" PRIu64
 173                    " for backend\n",
 174                    (uint64_t)(~net->dev.features & net->dev.backend_features));
 175             vhost_dev_cleanup(&net->dev);
 176             goto fail;
 177         }
 178     }
 179     /* Set sane init value. Override when guest acks. */
 180     vhost_net_ack_features(net, 0);
 181     return net;
 182 fail:
 183     g_free(net);
 184     return NULL;
 185 }
 186
 187 bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
 188 {
 189     return vhost_dev_query(&net->dev, dev);
 190 }
 191
 192 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
 193 {
 194     net->dev.vq_index = vq_index;
 195 }
 196
 197 static int vhost_net_start_one(struct vhost_net *net,
 198                                VirtIODevice *dev)
 199 {
 200     struct vhost_vring_file file = { };
 201     int r;
 202
 203     net->dev.nvqs = 2;
 204     net->dev.vqs = net->vqs;
 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->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
 260         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
 261             const VhostOps *vhost_ops = net->dev.vhost_ops;
 262             int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
 263                                           &file);
 264             assert(r >= 0);
 265         }
 266     }
 267     if (net->nc->info->poll) {
 268         net->nc->info->poll(net->nc, true);
 269     }
 270     vhost_dev_stop(&net->dev, dev);
 271     vhost_dev_disable_notifiers(&net->dev, dev);
 272 }
 273
 274 static bool vhost_net_device_endian_ok(VirtIODevice *vdev)
 275 {
 276 #ifdef TARGET_IS_BIENDIAN
 277 #ifdef HOST_WORDS_BIGENDIAN
 278     return virtio_is_big_endian(vdev);
 279 #else
 280     return !virtio_is_big_endian(vdev);
 281 #endif
 282 #else
 283     return true;
 284 #endif
 285 }
 286
 287 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
 288                     int total_queues)
 289 {
 290     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
 291     VirtioBusState *vbus = VIRTIO_BUS(qbus);
 292     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
 293     int r, e, i;
 294
 295     if (!vhost_net_device_endian_ok(dev)) {
 296         error_report("vhost-net does not support cross-endian");
 297         r = -ENOSYS;
 298         goto err;
 299     }
 300
 301     if (!k->set_guest_notifiers) {
 302         error_report("binding does not support guest notifiers");
 303         r = -ENOSYS;
 304         goto err;
 305     }
 306
 307     for (i = 0; i < total_queues; i++) {
 308         vhost_net_set_vq_index(get_vhost_net(ncs[i].peer), i * 2);
 309     }
 310
 311     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
 312     if (r < 0) {
 313         error_report("Error binding guest notifier: %d", -r);
 314         goto err;
 315     }
 316
 317     for (i = 0; i < total_queues; i++) {
 318         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
 319
 320         if (r < 0) {
 321             goto err_start;
 322         }
 323     }
 324
 325     return 0;
 326
 327 err_start:
 328     while (--i >= 0) {
 329         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
 330     }
 331     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
 332     if (e < 0) {
 333         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
 334         fflush(stderr);
 335     }
 336 err:
 337     return r;
 338 }
 339
 340 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
 341                     int total_queues)
 342 {
 343     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
 344     VirtioBusState *vbus = VIRTIO_BUS(qbus);
 345     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
 346     int i, r;
 347
 348     for (i = 0; i < total_queues; i++) {
 349         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
 350     }
 351
 352     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
 353     if (r < 0) {
 354         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
 355         fflush(stderr);
 356     }
 357     assert(r >= 0);
 358 }
 359
 360 void vhost_net_cleanup(struct vhost_net *net)
 361 {
 362     vhost_dev_cleanup(&net->dev);
 363     g_free(net);
 364 }
 365
 366 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 367 {
 368     return vhost_virtqueue_pending(&net->dev, idx);
 369 }
 370
 371 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 372                               int idx, bool mask)
 373 {
 374     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
 375 }
 376
 377 VHostNetState *get_vhost_net(NetClientState *nc)
 378 {
 379     VHostNetState *vhost_net = 0;
 380
 381     if (!nc) {
 382         return 0;
 383     }
 384
 385     switch (nc->info->type) {
 386     case NET_CLIENT_OPTIONS_KIND_TAP:
 387         vhost_net = tap_get_vhost_net(nc);
 388         break;
 389     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
 390         vhost_net = vhost_user_get_vhost_net(nc);
 391         break;
 392     default:
 393         break;
 394     }
 395
 396     return vhost_net;
 397 }
 398 #else
 399 struct vhost_net *vhost_net_init(VhostNetOptions *options)
 400 {
 401     error_report("vhost-net support is not compiled in");
 402     return NULL;
 403 }
 404
 405 bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
 406 {
 407     return false;
 408 }
 409
 410 int vhost_net_start(VirtIODevice *dev,
 411                     NetClientState *ncs,
 412                     int total_queues)
 413 {
 414     return -ENOSYS;
 415 }
 416 void vhost_net_stop(VirtIODevice *dev,
 417                     NetClientState *ncs,
 418                     int total_queues)
 419 {
 420 }
 421
 422 void vhost_net_cleanup(struct vhost_net *net)
 423 {
 424 }
 425
 426 unsigned vhost_net_get_features(struct vhost_net *net, unsigned features)
 427 {
 428     return features;
 429 }
 430 void vhost_net_ack_features(struct vhost_net *net, unsigned features)
 431 {
 432 }
 433
 434 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 435 {
 436     return false;
 437 }
 438
 439 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 440                               int idx, bool mask)
 441 {
 442 }
 443
 444 VHostNetState *get_vhost_net(NetClientState *nc)
 445 {
 446     return 0;
 447 }
 448 #endif