drivers/vhost/vsock.c

   1 /*
   2  * vhost transport for vsock
   3  *
   4  * Copyright (C) 2013-2015 Red Hat, Inc.
   5  * Author: Asias He <[email protected]>
   6  *         Stefan Hajnoczi <[email protected]>
   7  *
   8  * This work is licensed under the terms of the GNU GPL, version 2.
   9  */
  10 #include <linux/miscdevice.h>
  11 #include <linux/atomic.h>
  12 #include <linux/module.h>
  13 #include <linux/mutex.h>
  14 #include <linux/vmalloc.h>
  15 #include <net/sock.h>
  16 #include <linux/virtio_vsock.h>
  17 #include <linux/vhost.h>
  18
  19 #include <net/af_vsock.h>
  20 #include "vhost.h"
  21
  22 #define VHOST_VSOCK_DEFAULT_HOST_CID    2
  23
  24 enum {
  25         VHOST_VSOCK_FEATURES = VHOST_FEATURES,
  26 };
  27
  28 /* Used to track all the vhost_vsock instances on the system. */
  29 static DEFINE_SPINLOCK(vhost_vsock_lock);
  30 static LIST_HEAD(vhost_vsock_list);
  31
  32 struct vhost_vsock {
  33         struct vhost_dev dev;
  34         struct vhost_virtqueue vqs[2];
  35
  36         /* Link to global vhost_vsock_list, protected by vhost_vsock_lock */
  37         struct list_head list;
  38
  39         struct vhost_work send_pkt_work;
  40         spinlock_t send_pkt_list_lock;
  41         struct list_head send_pkt_list; /* host->guest pending packets */
  42
  43         atomic_t queued_replies;
  44
  45         u32 guest_cid;
  46 };
  47
  48 static u32 vhost_transport_get_local_cid(void)
  49 {
  50         return VHOST_VSOCK_DEFAULT_HOST_CID;
  51 }
  52
  53 static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
  54 {
  55         struct vhost_vsock *vsock;
  56
  57         spin_lock_bh(&vhost_vsock_lock);
  58         list_for_each_entry(vsock, &vhost_vsock_list, list) {
  59                 u32 other_cid = vsock->guest_cid;
  60
  61                 /* Skip instances that have no CID yet */
  62                 if (other_cid == 0)
  63                         continue;
  64
  65                 if (other_cid == guest_cid) {
  66                         spin_unlock_bh(&vhost_vsock_lock);
  67                         return vsock;
  68                 }
  69         }
  70         spin_unlock_bh(&vhost_vsock_lock);
  71
  72         return NULL;
  73 }
  74
  75 static void
  76 vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
  77                             struct vhost_virtqueue *vq)
  78 {
  79         struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
  80         bool added = false;
  81         bool restart_tx = false;
  82
  83         mutex_lock(&vq->mutex);
  84
  85         if (!vq->private_data)
  86                 goto out;
  87
  88         /* Avoid further vmexits, we're already processing the virtqueue */
  89         vhost_disable_notify(&vsock->dev, vq);
  90
  91         for (;;) {
  92                 struct virtio_vsock_pkt *pkt;
  93                 struct iov_iter iov_iter;
  94                 unsigned out, in;
  95                 size_t nbytes;
  96                 size_t len;
  97                 int head;
  98
  99                 spin_lock_bh(&vsock->send_pkt_list_lock);
 100                 if (list_empty(&vsock->send_pkt_list)) {
 101                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 102                         vhost_enable_notify(&vsock->dev, vq);
 103                         break;
 104                 }
 105
 106                 pkt = list_first_entry(&vsock->send_pkt_list,
 107                                        struct virtio_vsock_pkt, list);
 108                 list_del_init(&pkt->list);
 109                 spin_unlock_bh(&vsock->send_pkt_list_lock);
 110
 111                 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
 112                                          &out, &in, NULL, NULL);
 113                 if (head < 0) {
 114                         spin_lock_bh(&vsock->send_pkt_list_lock);
 115                         list_add(&pkt->list, &vsock->send_pkt_list);
 116                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 117                         break;
 118                 }
 119
 120                 if (head == vq->num) {
 121                         spin_lock_bh(&vsock->send_pkt_list_lock);
 122                         list_add(&pkt->list, &vsock->send_pkt_list);
 123                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 124
 125                         /* We cannot finish yet if more buffers snuck in while
 126                          * re-enabling notify.
 127                          */
 128                         if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
 129                                 vhost_disable_notify(&vsock->dev, vq);
 130                                 continue;
 131                         }
 132                         break;
 133                 }
 134
 135                 if (out) {
 136                         virtio_transport_free_pkt(pkt);
 137                         vq_err(vq, "Expected 0 output buffers, got %u\n", out);
 138                         break;
 139                 }
 140
 141                 len = iov_length(&vq->iov[out], in);
 142                 iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len);
 143
 144                 nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
 145                 if (nbytes != sizeof(pkt->hdr)) {
 146                         virtio_transport_free_pkt(pkt);
 147                         vq_err(vq, "Faulted on copying pkt hdr\n");
 148                         break;
 149                 }
 150
 151                 nbytes = copy_to_iter(pkt->buf, pkt->len, &iov_iter);
 152                 if (nbytes != pkt->len) {
 153                         virtio_transport_free_pkt(pkt);
 154                         vq_err(vq, "Faulted on copying pkt buf\n");
 155                         break;
 156                 }
 157
 158                 vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
 159                 added = true;
 160
 161                 if (pkt->reply) {
 162                         int val;
 163
 164                         val = atomic_dec_return(&vsock->queued_replies);
 165
 166                         /* Do we have resources to resume tx processing? */
 167                         if (val + 1 == tx_vq->num)
 168                                 restart_tx = true;
 169                 }
 170
 171                 virtio_transport_free_pkt(pkt);
 172         }
 173         if (added)
 174                 vhost_signal(&vsock->dev, vq);
 175
 176 out:
 177         mutex_unlock(&vq->mutex);
 178
 179         if (restart_tx)
 180                 vhost_poll_queue(&tx_vq->poll);
 181 }
 182
 183 static void vhost_transport_send_pkt_work(struct vhost_work *work)
 184 {
 185         struct vhost_virtqueue *vq;
 186         struct vhost_vsock *vsock;
 187
 188         vsock = container_of(work, struct vhost_vsock, send_pkt_work);
 189         vq = &vsock->vqs[VSOCK_VQ_RX];
 190
 191         vhost_transport_do_send_pkt(vsock, vq);
 192 }
 193
 194 static int
 195 vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt)
 196 {
 197         struct vhost_vsock *vsock;
 198         int len = pkt->len;
 199
 200         /* Find the vhost_vsock according to guest context id  */
 201         vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid));
 202         if (!vsock) {
 203                 virtio_transport_free_pkt(pkt);
 204                 return -ENODEV;
 205         }
 206
 207         if (pkt->reply)
 208                 atomic_inc(&vsock->queued_replies);
 209
 210         spin_lock_bh(&vsock->send_pkt_list_lock);
 211         list_add_tail(&pkt->list, &vsock->send_pkt_list);
 212         spin_unlock_bh(&vsock->send_pkt_list_lock);
 213
 214         vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
 215         return len;
 216 }
 217
 218 static struct virtio_vsock_pkt *
 219 vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
 220                       unsigned int out, unsigned int in)
 221 {
 222         struct virtio_vsock_pkt *pkt;
 223         struct iov_iter iov_iter;
 224         size_t nbytes;
 225         size_t len;
 226
 227         if (in != 0) {
 228                 vq_err(vq, "Expected 0 input buffers, got %u\n", in);
 229                 return NULL;
 230         }
 231
 232         pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
 233         if (!pkt)
 234                 return NULL;
 235
 236         len = iov_length(vq->iov, out);
 237         iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);
 238
 239         nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
 240         if (nbytes != sizeof(pkt->hdr)) {
 241                 vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
 242                        sizeof(pkt->hdr), nbytes);
 243                 kfree(pkt);
 244                 return NULL;
 245         }
 246
 247         if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM)
 248                 pkt->len = le32_to_cpu(pkt->hdr.len);
 249
 250         /* No payload */
 251         if (!pkt->len)
 252                 return pkt;
 253
 254         /* The pkt is too big */
 255         if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
 256                 kfree(pkt);
 257                 return NULL;
 258         }
 259
 260         pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
 261         if (!pkt->buf) {
 262                 kfree(pkt);
 263                 return NULL;
 264         }
 265
 266         nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
 267         if (nbytes != pkt->len) {
 268                 vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
 269                        pkt->len, nbytes);
 270                 virtio_transport_free_pkt(pkt);
 271                 return NULL;
 272         }
 273
 274         return pkt;
 275 }
 276
 277 /* Is there space left for replies to rx packets? */
 278 static bool vhost_vsock_more_replies(struct vhost_vsock *vsock)
 279 {
 280         struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX];
 281         int val;
 282
 283         smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
 284         val = atomic_read(&vsock->queued_replies);
 285
 286         return val < vq->num;
 287 }
 288
 289 static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
 290 {
 291         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
 292                                                   poll.work);
 293         struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
 294                                                  dev);
 295         struct virtio_vsock_pkt *pkt;
 296         int head;
 297         unsigned int out, in;
 298         bool added = false;
 299
 300         mutex_lock(&vq->mutex);
 301
 302         if (!vq->private_data)
 303                 goto out;
 304
 305         vhost_disable_notify(&vsock->dev, vq);
 306         for (;;) {
 307                 u32 len;
 308
 309                 if (!vhost_vsock_more_replies(vsock)) {
 310                         /* Stop tx until the device processes already
 311                          * pending replies.  Leave tx virtqueue
 312                          * callbacks disabled.
 313                          */
 314                         goto no_more_replies;
 315                 }
 316
 317                 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
 318                                          &out, &in, NULL, NULL);
 319                 if (head < 0)
 320                         break;
 321
 322                 if (head == vq->num) {
 323                         if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
 324                                 vhost_disable_notify(&vsock->dev, vq);
 325                                 continue;
 326                         }
 327                         break;
 328                 }
 329
 330                 pkt = vhost_vsock_alloc_pkt(vq, out, in);
 331                 if (!pkt) {
 332                         vq_err(vq, "Faulted on pkt\n");
 333                         continue;
 334                 }
 335
 336                 len = pkt->len;
 337
 338                 /* Only accept correctly addressed packets */
 339                 if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
 340                         virtio_transport_recv_pkt(pkt);
 341                 else
 342                         virtio_transport_free_pkt(pkt);
 343
 344                 vhost_add_used(vq, head, sizeof(pkt->hdr) + len);
 345                 added = true;
 346         }
 347
 348 no_more_replies:
 349         if (added)
 350                 vhost_signal(&vsock->dev, vq);
 351
 352 out:
 353         mutex_unlock(&vq->mutex);
 354 }
 355
 356 static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
 357 {
 358         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
 359                                                 poll.work);
 360         struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
 361                                                  dev);
 362
 363         vhost_transport_do_send_pkt(vsock, vq);
 364 }
 365
 366 static int vhost_vsock_start(struct vhost_vsock *vsock)
 367 {
 368         size_t i;
 369         int ret;
 370
 371         mutex_lock(&vsock->dev.mutex);
 372
 373         ret = vhost_dev_check_owner(&vsock->dev);
 374         if (ret)
 375                 goto err;
 376
 377         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 378                 struct vhost_virtqueue *vq = &vsock->vqs[i];
 379
 380                 mutex_lock(&vq->mutex);
 381
 382                 if (!vhost_vq_access_ok(vq)) {
 383                         ret = -EFAULT;
 384                         mutex_unlock(&vq->mutex);
 385                         goto err_vq;
 386                 }
 387
 388                 if (!vq->private_data) {
 389                         vq->private_data = vsock;
 390                         vhost_vq_init_access(vq);
 391                 }
 392
 393                 mutex_unlock(&vq->mutex);
 394         }
 395
 396         mutex_unlock(&vsock->dev.mutex);
 397         return 0;
 398
 399 err_vq:
 400         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 401                 struct vhost_virtqueue *vq = &vsock->vqs[i];
 402
 403                 mutex_lock(&vq->mutex);
 404                 vq->private_data = NULL;
 405                 mutex_unlock(&vq->mutex);
 406         }
 407 err:
 408         mutex_unlock(&vsock->dev.mutex);
 409         return ret;
 410 }
 411
 412 static int vhost_vsock_stop(struct vhost_vsock *vsock)
 413 {
 414         size_t i;
 415         int ret;
 416
 417         mutex_lock(&vsock->dev.mutex);
 418
 419         ret = vhost_dev_check_owner(&vsock->dev);
 420         if (ret)
 421                 goto err;
 422
 423         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 424                 struct vhost_virtqueue *vq = &vsock->vqs[i];
 425
 426                 mutex_lock(&vq->mutex);
 427                 vq->private_data = NULL;
 428                 mutex_unlock(&vq->mutex);
 429         }
 430
 431 err:
 432         mutex_unlock(&vsock->dev.mutex);
 433         return ret;
 434 }
 435
 436 static void vhost_vsock_free(struct vhost_vsock *vsock)
 437 {
 438         kvfree(vsock);
 439 }
 440
 441 static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
 442 {
 443         struct vhost_virtqueue **vqs;
 444         struct vhost_vsock *vsock;
 445         int ret;
 446
 447         /* This struct is large and allocation could fail, fall back to vmalloc
 448          * if there is no other way.
 449          */
 450         vsock = kzalloc(sizeof(*vsock), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
 451         if (!vsock) {
 452                 vsock = vmalloc(sizeof(*vsock));
 453                 if (!vsock)
 454                         return -ENOMEM;
 455         }
 456
 457         vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
 458         if (!vqs) {
 459                 ret = -ENOMEM;
 460                 goto out;
 461         }
 462
 463         atomic_set(&vsock->queued_replies, 0);
 464
 465         vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
 466         vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
 467         vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
 468         vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
 469
 470         vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs));
 471
 472         file->private_data = vsock;
 473         spin_lock_init(&vsock->send_pkt_list_lock);
 474         INIT_LIST_HEAD(&vsock->send_pkt_list);
 475         vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
 476
 477         spin_lock_bh(&vhost_vsock_lock);
 478         list_add_tail(&vsock->list, &vhost_vsock_list);
 479         spin_unlock_bh(&vhost_vsock_lock);
 480         return 0;
 481
 482 out:
 483         vhost_vsock_free(vsock);
 484         return ret;
 485 }
 486
 487 static void vhost_vsock_flush(struct vhost_vsock *vsock)
 488 {
 489         int i;
 490
 491         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++)
 492                 if (vsock->vqs[i].handle_kick)
 493                         vhost_poll_flush(&vsock->vqs[i].poll);
 494         vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
 495 }
 496
 497 static void vhost_vsock_reset_orphans(struct sock *sk)
 498 {
 499         struct vsock_sock *vsk = vsock_sk(sk);
 500
 501         /* vmci_transport.c doesn't take sk_lock here either.  At least we're
 502          * under vsock_table_lock so the sock cannot disappear while we're
 503          * executing.
 504          */
 505
 506         if (!vhost_vsock_get(vsk->remote_addr.svm_cid)) {
 507                 sock_set_flag(sk, SOCK_DONE);
 508                 vsk->peer_shutdown = SHUTDOWN_MASK;
 509                 sk->sk_state = SS_UNCONNECTED;
 510                 sk->sk_err = ECONNRESET;
 511                 sk->sk_error_report(sk);
 512         }
 513 }
 514
 515 static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
 516 {
 517         struct vhost_vsock *vsock = file->private_data;
 518
 519         spin_lock_bh(&vhost_vsock_lock);
 520         list_del(&vsock->list);
 521         spin_unlock_bh(&vhost_vsock_lock);
 522
 523         /* Iterating over all connections for all CIDs to find orphans is
 524          * inefficient.  Room for improvement here. */
 525         vsock_for_each_connected_socket(vhost_vsock_reset_orphans);
 526
 527         vhost_vsock_stop(vsock);
 528         vhost_vsock_flush(vsock);
 529         vhost_dev_stop(&vsock->dev);
 530
 531         spin_lock_bh(&vsock->send_pkt_list_lock);
 532         while (!list_empty(&vsock->send_pkt_list)) {
 533                 struct virtio_vsock_pkt *pkt;
 534
 535                 pkt = list_first_entry(&vsock->send_pkt_list,
 536                                 struct virtio_vsock_pkt, list);
 537                 list_del_init(&pkt->list);
 538                 virtio_transport_free_pkt(pkt);
 539         }
 540         spin_unlock_bh(&vsock->send_pkt_list_lock);
 541
 542         vhost_dev_cleanup(&vsock->dev, false);
 543         kfree(vsock->dev.vqs);
 544         vhost_vsock_free(vsock);
 545         return 0;
 546 }
 547
 548 static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
 549 {
 550         struct vhost_vsock *other;
 551
 552         /* Refuse reserved CIDs */
 553         if (guest_cid <= VMADDR_CID_HOST ||
 554             guest_cid == U32_MAX)
 555                 return -EINVAL;
 556
 557         /* 64-bit CIDs are not yet supported */
 558         if (guest_cid > U32_MAX)
 559                 return -EINVAL;
 560
 561         /* Refuse if CID is already in use */
 562         other = vhost_vsock_get(guest_cid);
 563         if (other && other != vsock)
 564                 return -EADDRINUSE;
 565
 566         spin_lock_bh(&vhost_vsock_lock);
 567         vsock->guest_cid = guest_cid;
 568         spin_unlock_bh(&vhost_vsock_lock);
 569
 570         return 0;
 571 }
 572
 573 static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
 574 {
 575         struct vhost_virtqueue *vq;
 576         int i;
 577
 578         if (features & ~VHOST_VSOCK_FEATURES)
 579                 return -EOPNOTSUPP;
 580
 581         mutex_lock(&vsock->dev.mutex);
 582         if ((features & (1 << VHOST_F_LOG_ALL)) &&
 583             !vhost_log_access_ok(&vsock->dev)) {
 584                 mutex_unlock(&vsock->dev.mutex);
 585                 return -EFAULT;
 586         }
 587
 588         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 589                 vq = &vsock->vqs[i];
 590                 mutex_lock(&vq->mutex);
 591                 vq->acked_features = features;
 592                 mutex_unlock(&vq->mutex);
 593         }
 594         mutex_unlock(&vsock->dev.mutex);
 595         return 0;
 596 }
 597
 598 static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
 599                                   unsigned long arg)
 600 {
 601         struct vhost_vsock *vsock = f->private_data;
 602         void __user *argp = (void __user *)arg;
 603         u64 guest_cid;
 604         u64 features;
 605         int start;
 606         int r;
 607
 608         switch (ioctl) {
 609         case VHOST_VSOCK_SET_GUEST_CID:
 610                 if (copy_from_user(&guest_cid, argp, sizeof(guest_cid)))
 611                         return -EFAULT;
 612                 return vhost_vsock_set_cid(vsock, guest_cid);
 613         case VHOST_VSOCK_SET_RUNNING:
 614                 if (copy_from_user(&start, argp, sizeof(start)))
 615                         return -EFAULT;
 616                 if (start)
 617                         return vhost_vsock_start(vsock);
 618                 else
 619                         return vhost_vsock_stop(vsock);
 620         case VHOST_GET_FEATURES:
 621                 features = VHOST_VSOCK_FEATURES;
 622                 if (copy_to_user(argp, &features, sizeof(features)))
 623                         return -EFAULT;
 624                 return 0;
 625         case VHOST_SET_FEATURES:
 626                 if (copy_from_user(&features, argp, sizeof(features)))
 627                         return -EFAULT;
 628                 return vhost_vsock_set_features(vsock, features);
 629         default:
 630                 mutex_lock(&vsock->dev.mutex);
 631                 r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
 632                 if (r == -ENOIOCTLCMD)
 633                         r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
 634                 else
 635                         vhost_vsock_flush(vsock);
 636                 mutex_unlock(&vsock->dev.mutex);
 637                 return r;
 638         }
 639 }
 640
 641 static const struct file_operations vhost_vsock_fops = {
 642         .owner          = THIS_MODULE,
 643         .open           = vhost_vsock_dev_open,
 644         .release        = vhost_vsock_dev_release,
 645         .llseek         = noop_llseek,
 646         .unlocked_ioctl = vhost_vsock_dev_ioctl,
 647 };
 648
 649 static struct miscdevice vhost_vsock_misc = {
 650         .minor = MISC_DYNAMIC_MINOR,
 651         .name = "vhost-vsock",
 652         .fops = &vhost_vsock_fops,
 653 };
 654
 655 static struct virtio_transport vhost_transport = {
 656         .transport = {
 657                 .get_local_cid            = vhost_transport_get_local_cid,
 658
 659                 .init                     = virtio_transport_do_socket_init,
 660                 .destruct                 = virtio_transport_destruct,
 661                 .release                  = virtio_transport_release,
 662                 .connect                  = virtio_transport_connect,
 663                 .shutdown                 = virtio_transport_shutdown,
 664
 665                 .dgram_enqueue            = virtio_transport_dgram_enqueue,
 666                 .dgram_dequeue            = virtio_transport_dgram_dequeue,
 667                 .dgram_bind               = virtio_transport_dgram_bind,
 668                 .dgram_allow              = virtio_transport_dgram_allow,
 669
 670                 .stream_enqueue           = virtio_transport_stream_enqueue,
 671                 .stream_dequeue           = virtio_transport_stream_dequeue,
 672                 .stream_has_data          = virtio_transport_stream_has_data,
 673                 .stream_has_space         = virtio_transport_stream_has_space,
 674                 .stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
 675                 .stream_is_active         = virtio_transport_stream_is_active,
 676                 .stream_allow             = virtio_transport_stream_allow,
 677
 678                 .notify_poll_in           = virtio_transport_notify_poll_in,
 679                 .notify_poll_out          = virtio_transport_notify_poll_out,
 680                 .notify_recv_init         = virtio_transport_notify_recv_init,
 681                 .notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
 682                 .notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
 683                 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
 684                 .notify_send_init         = virtio_transport_notify_send_init,
 685                 .notify_send_pre_block    = virtio_transport_notify_send_pre_block,
 686                 .notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
 687                 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
 688
 689                 .set_buffer_size          = virtio_transport_set_buffer_size,
 690                 .set_min_buffer_size      = virtio_transport_set_min_buffer_size,
 691                 .set_max_buffer_size      = virtio_transport_set_max_buffer_size,
 692                 .get_buffer_size          = virtio_transport_get_buffer_size,
 693                 .get_min_buffer_size      = virtio_transport_get_min_buffer_size,
 694                 .get_max_buffer_size      = virtio_transport_get_max_buffer_size,
 695         },
 696
 697         .send_pkt = vhost_transport_send_pkt,
 698 };
 699
 700 static int __init vhost_vsock_init(void)
 701 {
 702         int ret;
 703
 704         ret = vsock_core_init(&vhost_transport.transport);
 705         if (ret < 0)
 706                 return ret;
 707         return misc_register(&vhost_vsock_misc);
 708 };
 709
 710 static void __exit vhost_vsock_exit(void)
 711 {
 712         misc_deregister(&vhost_vsock_misc);
 713         vsock_core_exit();
 714 };
 715
 716 module_init(vhost_vsock_init);
 717 module_exit(vhost_vsock_exit);
 718 MODULE_LICENSE("GPL v2");
 719 MODULE_AUTHOR("Asias He");
 720 MODULE_DESCRIPTION("vhost transport for vsock ");