drivers/vhost/vsock.c

   1 /*
   2  * vhost transport for vsock
   3  *
   4  * Copyright (C) 2013-2015 Red Hat, Inc.
   5  * Author: Asias He <asias@redhat.com>
   6  *         Stefan Hajnoczi <stefanha@redhat.com>
   7  *
   8  * This work is licensed under the terms of the GNU GPL, version 2.
   9  */
  10 #include <linux/miscdevice.h>
  11 #include <linux/module.h>
  12 #include <linux/mutex.h>
  13 #include <net/sock.h>
  14 #include <linux/virtio_vsock.h>
  15 #include <linux/vhost.h>
  16
  17 #include <net/af_vsock.h>
  18 #include "vhost.h"
  19 #include "vsock.h"
  20
  21 #define VHOST_VSOCK_DEFAULT_HOST_CID    2
  22
  23 static int vhost_transport_socket_init(struct vsock_sock *vsk,
  24                                        struct vsock_sock *psk);
  25
  26 enum {
  27         VHOST_VSOCK_FEATURES = VHOST_FEATURES,
  28 };
  29
  30 /* Used to track all the vhost_vsock instances on the system. */
  31 static LIST_HEAD(vhost_vsock_list);
  32 static DEFINE_MUTEX(vhost_vsock_mutex);
  33
  34 struct vhost_vsock_virtqueue {
  35         struct vhost_virtqueue vq;
  36 };
  37
  38 struct vhost_vsock {
  39         /* Vhost device */
  40         struct vhost_dev dev;
  41         /* Vhost vsock virtqueue*/
  42         struct vhost_vsock_virtqueue vqs[VSOCK_VQ_MAX];
  43         /* Link to global vhost_vsock_list*/
  44         struct list_head list;
  45         /* Head for pkt from host to guest */
  46         struct list_head send_pkt_list;
  47         /* Work item to send pkt */
  48         struct vhost_work send_pkt_work;
  49         /* Wait queue for send pkt */
  50         wait_queue_head_t queue_wait;
  51         /* Used for global tx buf limitation */
  52         u32 total_tx_buf;
  53         /* Guest contex id this vhost_vsock instance handles */
  54         u32 guest_cid;
  55 };
  56
  57 static u32 vhost_transport_get_local_cid(void)
  58 {
  59         return VHOST_VSOCK_DEFAULT_HOST_CID;
  60 }
  61
  62 static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
  63 {
  64         struct vhost_vsock *vsock;
  65
  66         mutex_lock(&vhost_vsock_mutex);
  67         list_for_each_entry(vsock, &vhost_vsock_list, list) {
  68                 if (vsock->guest_cid == guest_cid) {
  69                         mutex_unlock(&vhost_vsock_mutex);
  70                         return vsock;
  71                 }
  72         }
  73         mutex_unlock(&vhost_vsock_mutex);
  74
  75         return NULL;
  76 }
  77
  78 static void
  79 vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
  80                             struct vhost_virtqueue *vq)
  81 {
  82         bool added = false;
  83
  84         mutex_lock(&vq->mutex);
  85         vhost_disable_notify(&vsock->dev, vq);
  86         for (;;) {
  87                 struct virtio_vsock_pkt *pkt;
  88                 struct iov_iter iov_iter;
  89                 unsigned out, in;
  90                 struct sock *sk;
  91                 size_t nbytes;
  92                 size_t len;
  93                 int head;
  94
  95                 if (list_empty(&vsock->send_pkt_list)) {
  96                         vhost_enable_notify(&vsock->dev, vq);
  97                         break;
  98                 }
  99
 100                 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
 101                                          &out, &in, NULL, NULL);
 102                 pr_debug("%s: head = %d\n", __func__, head);
 103                 if (head < 0)
 104                         break;
 105
 106                 if (head == vq->num) {
 107                         if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
 108                                 vhost_disable_notify(&vsock->dev, vq);
 109                                 continue;
 110                         }
 111                         break;
 112                 }
 113
 114                 pkt = list_first_entry(&vsock->send_pkt_list,
 115                                        struct virtio_vsock_pkt, list);
 116                 list_del_init(&pkt->list);
 117
 118                 if (out) {
 119                         virtio_transport_free_pkt(pkt);
 120                         vq_err(vq, "Expected 0 output buffers, got %u\n", out);
 121                         break;
 122                 }
 123
 124                 len = iov_length(&vq->iov[out], in);
 125                 iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len);
 126
 127                 nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
 128                 if (nbytes != sizeof(pkt->hdr)) {
 129                         virtio_transport_free_pkt(pkt);
 130                         vq_err(vq, "Faulted on copying pkt hdr\n");
 131                         break;
 132                 }
 133
 134                 nbytes = copy_to_iter(pkt->buf, pkt->len, &iov_iter);
 135                 if (nbytes != pkt->len) {
 136                         virtio_transport_free_pkt(pkt);
 137                         vq_err(vq, "Faulted on copying pkt buf\n");
 138                         break;
 139                 }
 140
 141                 vhost_add_used(vq, head, pkt->len); /* TODO should this be sizeof(pkt->hdr) + pkt->len? */
 142                 added = true;
 143
 144                 virtio_transport_dec_tx_pkt(pkt);
 145                 vsock->total_tx_buf -= pkt->len;
 146
 147                 sk = sk_vsock(pkt->trans->vsk);
 148                 /* Release refcnt taken in vhost_transport_send_pkt */
 149                 sock_put(sk);
 150
 151                 virtio_transport_free_pkt(pkt);
 152         }
 153         if (added)
 154                 vhost_signal(&vsock->dev, vq);
 155         mutex_unlock(&vq->mutex);
 156
 157         if (added)
 158                 wake_up(&vsock->queue_wait);
 159 }
 160
 161 static void vhost_transport_send_pkt_work(struct vhost_work *work)
 162 {
 163         struct vhost_virtqueue *vq;
 164         struct vhost_vsock *vsock;
 165
 166         vsock = container_of(work, struct vhost_vsock, send_pkt_work);
 167         vq = &vsock->vqs[VSOCK_VQ_RX].vq;
 168
 169         vhost_transport_do_send_pkt(vsock, vq);
 170 }
 171
 172 static int
 173 vhost_transport_send_pkt(struct vsock_sock *vsk,
 174                          struct virtio_vsock_pkt_info *info)
 175 {
 176         u32 src_cid, src_port, dst_cid, dst_port;
 177         struct virtio_transport *trans;
 178         struct virtio_vsock_pkt *pkt;
 179         struct vhost_virtqueue *vq;
 180         struct vhost_vsock *vsock;
 181         u32 pkt_len = info->pkt_len;
 182         DEFINE_WAIT(wait);
 183
 184         src_cid = vhost_transport_get_local_cid();
 185         src_port = vsk->local_addr.svm_port;
 186         if (!info->remote_cid) {
 187                 dst_cid = vsk->remote_addr.svm_cid;
 188                 dst_port = vsk->remote_addr.svm_port;
 189         } else {
 190                 dst_cid = info->remote_cid;
 191                 dst_port = info->remote_port;
 192         }
 193
 194         /* Find the vhost_vsock according to guest context id  */
 195         vsock = vhost_vsock_get(dst_cid);
 196         if (!vsock)
 197                 return -ENODEV;
 198
 199         trans = vsk->trans;
 200         vq = &vsock->vqs[VSOCK_VQ_RX].vq;
 201
 202         /* we can send less than pkt_len bytes */
 203         if (pkt_len > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE)
 204                 pkt_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
 205
 206         /* virtio_transport_get_credit might return less than pkt_len credit */
 207         pkt_len = virtio_transport_get_credit(trans, pkt_len);
 208
 209         /* Do not send zero length OP_RW pkt*/
 210         if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
 211                 return pkt_len;
 212
 213         /* Respect global tx buf limitation */
 214         mutex_lock(&vq->mutex);
 215         while (pkt_len + vsock->total_tx_buf > VIRTIO_VSOCK_MAX_TX_BUF_SIZE) {
 216                 prepare_to_wait_exclusive(&vsock->queue_wait, &wait,
 217                                           TASK_UNINTERRUPTIBLE);
 218                 mutex_unlock(&vq->mutex);
 219                 schedule();
 220                 mutex_lock(&vq->mutex);
 221                 finish_wait(&vsock->queue_wait, &wait);
 222         }
 223         vsock->total_tx_buf += pkt_len;
 224         mutex_unlock(&vq->mutex);
 225
 226         pkt = virtio_transport_alloc_pkt(vsk, info, pkt_len,
 227                                          src_cid, src_port,
 228                                          dst_cid, dst_port);
 229         if (!pkt) {
 230                 mutex_lock(&vq->mutex);
 231                 vsock->total_tx_buf -= pkt_len;
 232                 mutex_unlock(&vq->mutex);
 233                 virtio_transport_put_credit(trans, pkt_len);
 234                 return -ENOMEM;
 235         }
 236
 237         pr_debug("%s:info->pkt_len= %d\n", __func__, pkt_len);
 238         /* Released in vhost_transport_do_send_pkt */
 239         sock_hold(&trans->vsk->sk);
 240         virtio_transport_inc_tx_pkt(pkt);
 241
 242         /* Queue it up in vhost work */
 243         mutex_lock(&vq->mutex);
 244         list_add_tail(&pkt->list, &vsock->send_pkt_list);
 245         vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
 246         mutex_unlock(&vq->mutex);
 247
 248         return pkt_len;
 249 }
 250
 251 static struct virtio_transport_pkt_ops vhost_ops = {
 252         .send_pkt = vhost_transport_send_pkt,
 253 };
 254
 255 static struct virtio_vsock_pkt *
 256 vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
 257                       unsigned int out, unsigned int in)
 258 {
 259         struct virtio_vsock_pkt *pkt;
 260         struct iov_iter iov_iter;
 261         size_t nbytes;
 262         size_t len;
 263
 264         if (in != 0) {
 265                 vq_err(vq, "Expected 0 input buffers, got %u\n", in);
 266                 return NULL;
 267         }
 268
 269         pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
 270         if (!pkt)
 271                 return NULL;
 272
 273         len = iov_length(vq->iov, out);
 274         iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);
 275
 276         nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
 277         if (nbytes != sizeof(pkt->hdr)) {
 278                 vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
 279                        sizeof(pkt->hdr), nbytes);
 280                 kfree(pkt);
 281                 return NULL;
 282         }
 283
 284         if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_DGRAM)
 285                 pkt->len = le32_to_cpu(pkt->hdr.len) & 0XFFFF;
 286         else if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM)
 287                 pkt->len = le32_to_cpu(pkt->hdr.len);
 288
 289         /* No payload */
 290         if (!pkt->len)
 291                 return pkt;
 292
 293         /* The pkt is too big */
 294         if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
 295                 kfree(pkt);
 296                 return NULL;
 297         }
 298
 299         pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
 300         if (!pkt->buf) {
 301                 kfree(pkt);
 302                 return NULL;
 303         }
 304
 305         nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
 306         if (nbytes != pkt->len) {
 307                 vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
 308                        pkt->len, nbytes);
 309                 virtio_transport_free_pkt(pkt);
 310                 return NULL;
 311         }
 312
 313         return pkt;
 314 }
 315
 316 static void vhost_vsock_handle_ctl_kick(struct vhost_work *work)
 317 {
 318         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
 319                                                   poll.work);
 320         struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
 321                                                  dev);
 322
 323         pr_debug("%s vq=%p, vsock=%p\n", __func__, vq, vsock);
 324 }
 325
 326 static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
 327 {
 328         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
 329                                                   poll.work);
 330         struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
 331                                                  dev);
 332         struct virtio_vsock_pkt *pkt;
 333         int head;
 334         unsigned int out, in;
 335         bool added = false;
 336         u32 len;
 337
 338         mutex_lock(&vq->mutex);
 339         vhost_disable_notify(&vsock->dev, vq);
 340         for (;;) {
 341                 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
 342                                          &out, &in, NULL, NULL);
 343                 if (head < 0)
 344                         break;
 345
 346                 if (head == vq->num) {
 347                         if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
 348                                 vhost_disable_notify(&vsock->dev, vq);
 349                                 continue;
 350                         }
 351                         break;
 352                 }
 353
 354                 pkt = vhost_vsock_alloc_pkt(vq, out, in);
 355                 if (!pkt) {
 356                         vq_err(vq, "Faulted on pkt\n");
 357                         continue;
 358                 }
 359
 360                 len = pkt->len;
 361
 362                 /* Only accept correctly addressed packets */
 363                 if (le32_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid &&
 364                     le32_to_cpu(pkt->hdr.dst_cid) == vhost_transport_get_local_cid())
 365                         virtio_transport_recv_pkt(pkt);
 366                 else
 367                         virtio_transport_free_pkt(pkt);
 368
 369                 vhost_add_used(vq, head, len);
 370                 added = true;
 371         }
 372         if (added)
 373                 vhost_signal(&vsock->dev, vq);
 374         mutex_unlock(&vq->mutex);
 375 }
 376
 377 static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
 378 {
 379         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
 380                                                 poll.work);
 381         struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
 382                                                  dev);
 383
 384         vhost_transport_do_send_pkt(vsock, vq);
 385 }
 386
 387 static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
 388 {
 389         struct vhost_virtqueue **vqs;
 390         struct vhost_vsock *vsock;
 391         int ret;
 392
 393         vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
 394         if (!vsock)
 395                 return -ENOMEM;
 396
 397         pr_debug("%s:vsock=%p\n", __func__, vsock);
 398
 399         vqs = kmalloc(VSOCK_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
 400         if (!vqs) {
 401                 ret = -ENOMEM;
 402                 goto out;
 403         }
 404
 405         vqs[VSOCK_VQ_CTRL] = &vsock->vqs[VSOCK_VQ_CTRL].vq;
 406         vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX].vq;
 407         vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX].vq;
 408         vsock->vqs[VSOCK_VQ_CTRL].vq.handle_kick = vhost_vsock_handle_ctl_kick;
 409         vsock->vqs[VSOCK_VQ_TX].vq.handle_kick = vhost_vsock_handle_tx_kick;
 410         vsock->vqs[VSOCK_VQ_RX].vq.handle_kick = vhost_vsock_handle_rx_kick;
 411
 412         vhost_dev_init(&vsock->dev, vqs, VSOCK_VQ_MAX);
 413
 414         file->private_data = vsock;
 415         init_waitqueue_head(&vsock->queue_wait);
 416         INIT_LIST_HEAD(&vsock->send_pkt_list);
 417         vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
 418
 419         mutex_lock(&vhost_vsock_mutex);
 420         list_add_tail(&vsock->list, &vhost_vsock_list);
 421         mutex_unlock(&vhost_vsock_mutex);
 422         return 0;
 423
 424 out:
 425         kfree(vsock);
 426         return ret;
 427 }
 428
 429 static void vhost_vsock_flush(struct vhost_vsock *vsock)
 430 {
 431         int i;
 432
 433         for (i = 0; i < VSOCK_VQ_MAX; i++)
 434                 vhost_poll_flush(&vsock->vqs[i].vq.poll);
 435         vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
 436 }
 437
 438 static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
 439 {
 440         struct vhost_vsock *vsock = file->private_data;
 441
 442         mutex_lock(&vhost_vsock_mutex);
 443         list_del(&vsock->list);
 444         mutex_unlock(&vhost_vsock_mutex);
 445
 446         vhost_dev_stop(&vsock->dev);
 447         vhost_vsock_flush(vsock);
 448         vhost_dev_cleanup(&vsock->dev, false);
 449         kfree(vsock->dev.vqs);
 450         kfree(vsock);
 451         return 0;
 452 }
 453
 454 static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u32 guest_cid)
 455 {
 456         struct vhost_vsock *other;
 457
 458         /* Refuse reserved CIDs */
 459         if (guest_cid <= VMADDR_CID_HOST) {
 460                 return -EINVAL;
 461         }
 462
 463         /* Refuse if CID is already in use */
 464         other = vhost_vsock_get(guest_cid);
 465         if (other && other != vsock) {
 466                 return -EADDRINUSE;
 467         }
 468
 469         mutex_lock(&vhost_vsock_mutex);
 470         vsock->guest_cid = guest_cid;
 471         pr_debug("%s:guest_cid=%d\n", __func__, guest_cid);
 472         mutex_unlock(&vhost_vsock_mutex);
 473
 474         return 0;
 475 }
 476
 477 static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
 478 {
 479         struct vhost_virtqueue *vq;
 480         int i;
 481
 482         if (features & ~VHOST_VSOCK_FEATURES)
 483                 return -EOPNOTSUPP;
 484
 485         mutex_lock(&vsock->dev.mutex);
 486         if ((features & (1 << VHOST_F_LOG_ALL)) &&
 487             !vhost_log_access_ok(&vsock->dev)) {
 488                 mutex_unlock(&vsock->dev.mutex);
 489                 return -EFAULT;
 490         }
 491
 492         for (i = 0; i < VSOCK_VQ_MAX; i++) {
 493                 vq = &vsock->vqs[i].vq;
 494                 mutex_lock(&vq->mutex);
 495                 vq->acked_features = features;
 496                 mutex_unlock(&vq->mutex);
 497         }
 498         mutex_unlock(&vsock->dev.mutex);
 499         return 0;
 500 }
 501
 502 static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
 503                                   unsigned long arg)
 504 {
 505         struct vhost_vsock *vsock = f->private_data;
 506         void __user *argp = (void __user *)arg;
 507         u64 __user *featurep = argp;
 508         u32 __user *cidp = argp;
 509         u32 guest_cid;
 510         u64 features;
 511         int r;
 512
 513         switch (ioctl) {
 514         case VHOST_VSOCK_SET_GUEST_CID:
 515                 if (get_user(guest_cid, cidp))
 516                         return -EFAULT;
 517                 return vhost_vsock_set_cid(vsock, guest_cid);
 518         case VHOST_GET_FEATURES:
 519                 features = VHOST_VSOCK_FEATURES;
 520                 if (copy_to_user(featurep, &features, sizeof(features)))
 521                         return -EFAULT;
 522                 return 0;
 523         case VHOST_SET_FEATURES:
 524                 if (copy_from_user(&features, featurep, sizeof(features)))
 525                         return -EFAULT;
 526                 return vhost_vsock_set_features(vsock, features);
 527         default:
 528                 mutex_lock(&vsock->dev.mutex);
 529                 r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
 530                 if (r == -ENOIOCTLCMD)
 531                         r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
 532                 else
 533                         vhost_vsock_flush(vsock);
 534                 mutex_unlock(&vsock->dev.mutex);
 535                 return r;
 536         }
 537 }
 538
 539 static const struct file_operations vhost_vsock_fops = {
 540         .owner          = THIS_MODULE,
 541         .open           = vhost_vsock_dev_open,
 542         .release        = vhost_vsock_dev_release,
 543         .llseek         = noop_llseek,
 544         .unlocked_ioctl = vhost_vsock_dev_ioctl,
 545 };
 546
 547 static struct miscdevice vhost_vsock_misc = {
 548         .minor = MISC_DYNAMIC_MINOR,
 549         .name = "vhost-vsock",
 550         .fops = &vhost_vsock_fops,
 551 };
 552
 553 static int
 554 vhost_transport_socket_init(struct vsock_sock *vsk, struct vsock_sock *psk)
 555 {
 556         struct virtio_transport *trans;
 557         int ret;
 558
 559         ret = virtio_transport_do_socket_init(vsk, psk);
 560         if (ret)
 561                 return ret;
 562
 563         trans = vsk->trans;
 564         trans->ops = &vhost_ops;
 565
 566         return ret;
 567 }
 568
 569 static struct vsock_transport vhost_transport = {
 570         .get_local_cid            = vhost_transport_get_local_cid,
 571
 572         .init                     = vhost_transport_socket_init,
 573         .destruct                 = virtio_transport_destruct,
 574         .release                  = virtio_transport_release,
 575         .connect                  = virtio_transport_connect,
 576         .shutdown                 = virtio_transport_shutdown,
 577
 578         .dgram_enqueue            = virtio_transport_dgram_enqueue,
 579         .dgram_dequeue            = virtio_transport_dgram_dequeue,
 580         .dgram_bind               = virtio_transport_dgram_bind,
 581         .dgram_allow              = virtio_transport_dgram_allow,
 582
 583         .stream_enqueue           = virtio_transport_stream_enqueue,
 584         .stream_dequeue           = virtio_transport_stream_dequeue,
 585         .stream_has_data          = virtio_transport_stream_has_data,
 586         .stream_has_space         = virtio_transport_stream_has_space,
 587         .stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
 588         .stream_is_active         = virtio_transport_stream_is_active,
 589         .stream_allow             = virtio_transport_stream_allow,
 590
 591         .notify_poll_in           = virtio_transport_notify_poll_in,
 592         .notify_poll_out          = virtio_transport_notify_poll_out,
 593         .notify_recv_init         = virtio_transport_notify_recv_init,
 594         .notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
 595         .notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
 596         .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
 597         .notify_send_init         = virtio_transport_notify_send_init,
 598         .notify_send_pre_block    = virtio_transport_notify_send_pre_block,
 599         .notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
 600         .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
 601
 602         .set_buffer_size          = virtio_transport_set_buffer_size,
 603         .set_min_buffer_size      = virtio_transport_set_min_buffer_size,
 604         .set_max_buffer_size      = virtio_transport_set_max_buffer_size,
 605         .get_buffer_size          = virtio_transport_get_buffer_size,
 606         .get_min_buffer_size      = virtio_transport_get_min_buffer_size,
 607         .get_max_buffer_size      = virtio_transport_get_max_buffer_size,
 608 };
 609
 610 static int __init vhost_vsock_init(void)
 611 {
 612         int ret;
 613
 614         ret = vsock_core_init(&vhost_transport);
 615         if (ret < 0)
 616                 return ret;
 617         return misc_register(&vhost_vsock_misc);
 618 };
 619
 620 static void __exit vhost_vsock_exit(void)
 621 {
 622         misc_deregister(&vhost_vsock_misc);
 623         vsock_core_exit();
 624 };
 625
 626 module_init(vhost_vsock_init);
 627 module_exit(vhost_vsock_exit);
 628 MODULE_LICENSE("GPL v2");
 629 MODULE_AUTHOR("Asias He");
 630 MODULE_DESCRIPTION("vhost transport for vsock ");