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/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         list_for_each_entry(vsock, &vhost_vsock_list, list) {
  58                 u32 other_cid = vsock->guest_cid;
  59
  60                 /* Skip instances that have no CID yet */
  61                 if (other_cid == 0)
  62                         continue;
  63
  64                 if (other_cid == guest_cid) {
  65                         return vsock;
  66                 }
  67         }
  68
  69         return NULL;
  70 }
  71
  72 static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
  73 {
  74         struct vhost_vsock *vsock;
  75
  76         spin_lock_bh(&vhost_vsock_lock);
  77         vsock = __vhost_vsock_get(guest_cid);
  78         spin_unlock_bh(&vhost_vsock_lock);
  79
  80         return vsock;
  81 }
  82
  83 static void
  84 vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
  85                             struct vhost_virtqueue *vq)
  86 {
  87         struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
  88         bool added = false;
  89         bool restart_tx = false;
  90
  91         mutex_lock(&vq->mutex);
  92
  93         if (!vq->private_data)
  94                 goto out;
  95
  96         /* Avoid further vmexits, we're already processing the virtqueue */
  97         vhost_disable_notify(&vsock->dev, vq);
  98
  99         for (;;) {
 100                 struct virtio_vsock_pkt *pkt;
 101                 struct iov_iter iov_iter;
 102                 unsigned out, in;
 103                 size_t nbytes;
 104                 size_t len;
 105                 int head;
 106
 107                 spin_lock_bh(&vsock->send_pkt_list_lock);
 108                 if (list_empty(&vsock->send_pkt_list)) {
 109                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 110                         vhost_enable_notify(&vsock->dev, vq);
 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                 spin_unlock_bh(&vsock->send_pkt_list_lock);
 118
 119                 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
 120                                          &out, &in, NULL, NULL);
 121                 if (head < 0) {
 122                         spin_lock_bh(&vsock->send_pkt_list_lock);
 123                         list_add(&pkt->list, &vsock->send_pkt_list);
 124                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 125                         break;
 126                 }
 127
 128                 if (head == vq->num) {
 129                         spin_lock_bh(&vsock->send_pkt_list_lock);
 130                         list_add(&pkt->list, &vsock->send_pkt_list);
 131                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 132
 133                         /* We cannot finish yet if more buffers snuck in while
 134                          * re-enabling notify.
 135                          */
 136                         if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
 137                                 vhost_disable_notify(&vsock->dev, vq);
 138                                 continue;
 139                         }
 140                         break;
 141                 }
 142
 143                 if (out) {
 144                         virtio_transport_free_pkt(pkt);
 145                         vq_err(vq, "Expected 0 output buffers, got %u\n", out);
 146                         break;
 147                 }
 148
 149                 len = iov_length(&vq->iov[out], in);
 150                 iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len);
 151
 152                 nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
 153                 if (nbytes != sizeof(pkt->hdr)) {
 154                         virtio_transport_free_pkt(pkt);
 155                         vq_err(vq, "Faulted on copying pkt hdr\n");
 156                         break;
 157                 }
 158
 159                 nbytes = copy_to_iter(pkt->buf, pkt->len, &iov_iter);
 160                 if (nbytes != pkt->len) {
 161                         virtio_transport_free_pkt(pkt);
 162                         vq_err(vq, "Faulted on copying pkt buf\n");
 163                         break;
 164                 }
 165
 166                 vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
 167                 added = true;
 168
 169                 if (pkt->reply) {
 170                         int val;
 171
 172                         val = atomic_dec_return(&vsock->queued_replies);
 173
 174                         /* Do we have resources to resume tx processing? */
 175                         if (val + 1 == tx_vq->num)
 176                                 restart_tx = true;
 177                 }
 178
 179                 virtio_transport_free_pkt(pkt);
 180         }
 181         if (added)
 182                 vhost_signal(&vsock->dev, vq);
 183
 184 out:
 185         mutex_unlock(&vq->mutex);
 186
 187         if (restart_tx)
 188                 vhost_poll_queue(&tx_vq->poll);
 189 }
 190
 191 static void vhost_transport_send_pkt_work(struct vhost_work *work)
 192 {
 193         struct vhost_virtqueue *vq;
 194         struct vhost_vsock *vsock;
 195
 196         vsock = container_of(work, struct vhost_vsock, send_pkt_work);
 197         vq = &vsock->vqs[VSOCK_VQ_RX];
 198
 199         vhost_transport_do_send_pkt(vsock, vq);
 200 }
 201
 202 static int
 203 vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt)
 204 {
 205         struct vhost_vsock *vsock;
 206         int len = pkt->len;
 207
 208         /* Find the vhost_vsock according to guest context id  */
 209         vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid));
 210         if (!vsock) {
 211                 virtio_transport_free_pkt(pkt);
 212                 return -ENODEV;
 213         }
 214
 215         if (pkt->reply)
 216                 atomic_inc(&vsock->queued_replies);
 217
 218         spin_lock_bh(&vsock->send_pkt_list_lock);
 219         list_add_tail(&pkt->list, &vsock->send_pkt_list);
 220         spin_unlock_bh(&vsock->send_pkt_list_lock);
 221
 222         vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
 223         return len;
 224 }
 225
 226 static int
 227 vhost_transport_cancel_pkt(struct vsock_sock *vsk)
 228 {
 229         struct vhost_vsock *vsock;
 230         struct virtio_vsock_pkt *pkt, *n;
 231         int cnt = 0;
 232         LIST_HEAD(freeme);
 233
 234         /* Find the vhost_vsock according to guest context id  */
 235         vsock = vhost_vsock_get(vsk->remote_addr.svm_cid);
 236         if (!vsock)
 237                 return -ENODEV;
 238
 239         spin_lock_bh(&vsock->send_pkt_list_lock);
 240         list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
 241                 if (pkt->vsk != vsk)
 242                         continue;
 243                 list_move(&pkt->list, &freeme);
 244         }
 245         spin_unlock_bh(&vsock->send_pkt_list_lock);
 246
 247         list_for_each_entry_safe(pkt, n, &freeme, list) {
 248                 if (pkt->reply)
 249                         cnt++;
 250                 list_del(&pkt->list);
 251                 virtio_transport_free_pkt(pkt);
 252         }
 253
 254         if (cnt) {
 255                 struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
 256                 int new_cnt;
 257
 258                 new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
 259                 if (new_cnt + cnt >= tx_vq->num && new_cnt < tx_vq->num)
 260                         vhost_poll_queue(&tx_vq->poll);
 261         }
 262
 263         return 0;
 264 }
 265
 266 static struct virtio_vsock_pkt *
 267 vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
 268                       unsigned int out, unsigned int in)
 269 {
 270         struct virtio_vsock_pkt *pkt;
 271         struct iov_iter iov_iter;
 272         size_t nbytes;
 273         size_t len;
 274
 275         if (in != 0) {
 276                 vq_err(vq, "Expected 0 input buffers, got %u\n", in);
 277                 return NULL;
 278         }
 279
 280         pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
 281         if (!pkt)
 282                 return NULL;
 283
 284         len = iov_length(vq->iov, out);
 285         iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);
 286
 287         nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
 288         if (nbytes != sizeof(pkt->hdr)) {
 289                 vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
 290                        sizeof(pkt->hdr), nbytes);
 291                 kfree(pkt);
 292                 return NULL;
 293         }
 294
 295         if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM)
 296                 pkt->len = le32_to_cpu(pkt->hdr.len);
 297
 298         /* No payload */
 299         if (!pkt->len)
 300                 return pkt;
 301
 302         /* The pkt is too big */
 303         if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
 304                 kfree(pkt);
 305                 return NULL;
 306         }
 307
 308         pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
 309         if (!pkt->buf) {
 310                 kfree(pkt);
 311                 return NULL;
 312         }
 313
 314         nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
 315         if (nbytes != pkt->len) {
 316                 vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
 317                        pkt->len, nbytes);
 318                 virtio_transport_free_pkt(pkt);
 319                 return NULL;
 320         }
 321
 322         return pkt;
 323 }
 324
 325 /* Is there space left for replies to rx packets? */
 326 static bool vhost_vsock_more_replies(struct vhost_vsock *vsock)
 327 {
 328         struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX];
 329         int val;
 330
 331         smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
 332         val = atomic_read(&vsock->queued_replies);
 333
 334         return val < vq->num;
 335 }
 336
 337 static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
 338 {
 339         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
 340                                                   poll.work);
 341         struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
 342                                                  dev);
 343         struct virtio_vsock_pkt *pkt;
 344         int head;
 345         unsigned int out, in;
 346         bool added = false;
 347
 348         mutex_lock(&vq->mutex);
 349
 350         if (!vq->private_data)
 351                 goto out;
 352
 353         vhost_disable_notify(&vsock->dev, vq);
 354         for (;;) {
 355                 u32 len;
 356
 357                 if (!vhost_vsock_more_replies(vsock)) {
 358                         /* Stop tx until the device processes already
 359                          * pending replies.  Leave tx virtqueue
 360                          * callbacks disabled.
 361                          */
 362                         goto no_more_replies;
 363                 }
 364
 365                 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
 366                                          &out, &in, NULL, NULL);
 367                 if (head < 0)
 368                         break;
 369
 370                 if (head == vq->num) {
 371                         if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
 372                                 vhost_disable_notify(&vsock->dev, vq);
 373                                 continue;
 374                         }
 375                         break;
 376                 }
 377
 378                 pkt = vhost_vsock_alloc_pkt(vq, out, in);
 379                 if (!pkt) {
 380                         vq_err(vq, "Faulted on pkt\n");
 381                         continue;
 382                 }
 383
 384                 len = pkt->len;
 385
 386                 /* Only accept correctly addressed packets */
 387                 if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
 388                         virtio_transport_recv_pkt(pkt);
 389                 else
 390                         virtio_transport_free_pkt(pkt);
 391
 392                 vhost_add_used(vq, head, sizeof(pkt->hdr) + len);
 393                 added = true;
 394         }
 395
 396 no_more_replies:
 397         if (added)
 398                 vhost_signal(&vsock->dev, vq);
 399
 400 out:
 401         mutex_unlock(&vq->mutex);
 402 }
 403
 404 static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
 405 {
 406         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
 407                                                 poll.work);
 408         struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
 409                                                  dev);
 410
 411         vhost_transport_do_send_pkt(vsock, vq);
 412 }
 413
 414 static int vhost_vsock_start(struct vhost_vsock *vsock)
 415 {
 416         struct vhost_virtqueue *vq;
 417         size_t i;
 418         int ret;
 419
 420         mutex_lock(&vsock->dev.mutex);
 421
 422         ret = vhost_dev_check_owner(&vsock->dev);
 423         if (ret)
 424                 goto err;
 425
 426         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 427                 vq = &vsock->vqs[i];
 428
 429                 mutex_lock(&vq->mutex);
 430
 431                 if (!vhost_vq_access_ok(vq)) {
 432                         ret = -EFAULT;
 433                         goto err_vq;
 434                 }
 435
 436                 if (!vq->private_data) {
 437                         vq->private_data = vsock;
 438                         ret = vhost_vq_init_access(vq);
 439                         if (ret)
 440                                 goto err_vq;
 441                 }
 442
 443                 mutex_unlock(&vq->mutex);
 444         }
 445
 446         mutex_unlock(&vsock->dev.mutex);
 447         return 0;
 448
 449 err_vq:
 450         vq->private_data = NULL;
 451         mutex_unlock(&vq->mutex);
 452
 453         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 454                 vq = &vsock->vqs[i];
 455
 456                 mutex_lock(&vq->mutex);
 457                 vq->private_data = NULL;
 458                 mutex_unlock(&vq->mutex);
 459         }
 460 err:
 461         mutex_unlock(&vsock->dev.mutex);
 462         return ret;
 463 }
 464
 465 static int vhost_vsock_stop(struct vhost_vsock *vsock)
 466 {
 467         size_t i;
 468         int ret;
 469
 470         mutex_lock(&vsock->dev.mutex);
 471
 472         ret = vhost_dev_check_owner(&vsock->dev);
 473         if (ret)
 474                 goto err;
 475
 476         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 477                 struct vhost_virtqueue *vq = &vsock->vqs[i];
 478
 479                 mutex_lock(&vq->mutex);
 480                 vq->private_data = NULL;
 481                 mutex_unlock(&vq->mutex);
 482         }
 483
 484 err:
 485         mutex_unlock(&vsock->dev.mutex);
 486         return ret;
 487 }
 488
 489 static void vhost_vsock_free(struct vhost_vsock *vsock)
 490 {
 491         kvfree(vsock);
 492 }
 493
 494 static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
 495 {
 496         struct vhost_virtqueue **vqs;
 497         struct vhost_vsock *vsock;
 498         int ret;
 499
 500         /* This struct is large and allocation could fail, fall back to vmalloc
 501          * if there is no other way.
 502          */
 503         vsock = kzalloc(sizeof(*vsock), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
 504         if (!vsock) {
 505                 vsock = vmalloc(sizeof(*vsock));
 506                 if (!vsock)
 507                         return -ENOMEM;
 508         }
 509
 510         vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
 511         if (!vqs) {
 512                 ret = -ENOMEM;
 513                 goto out;
 514         }
 515
 516         atomic_set(&vsock->queued_replies, 0);
 517
 518         vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
 519         vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
 520         vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
 521         vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
 522
 523         vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs));
 524
 525         file->private_data = vsock;
 526         spin_lock_init(&vsock->send_pkt_list_lock);
 527         INIT_LIST_HEAD(&vsock->send_pkt_list);
 528         vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
 529
 530         spin_lock_bh(&vhost_vsock_lock);
 531         list_add_tail(&vsock->list, &vhost_vsock_list);
 532         spin_unlock_bh(&vhost_vsock_lock);
 533         return 0;
 534
 535 out:
 536         vhost_vsock_free(vsock);
 537         return ret;
 538 }
 539
 540 static void vhost_vsock_flush(struct vhost_vsock *vsock)
 541 {
 542         int i;
 543
 544         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++)
 545                 if (vsock->vqs[i].handle_kick)
 546                         vhost_poll_flush(&vsock->vqs[i].poll);
 547         vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
 548 }
 549
 550 static void vhost_vsock_reset_orphans(struct sock *sk)
 551 {
 552         struct vsock_sock *vsk = vsock_sk(sk);
 553
 554         /* vmci_transport.c doesn't take sk_lock here either.  At least we're
 555          * under vsock_table_lock so the sock cannot disappear while we're
 556          * executing.
 557          */
 558
 559         if (!vhost_vsock_get(vsk->remote_addr.svm_cid)) {
 560                 sock_set_flag(sk, SOCK_DONE);
 561                 vsk->peer_shutdown = SHUTDOWN_MASK;
 562                 sk->sk_state = SS_UNCONNECTED;
 563                 sk->sk_err = ECONNRESET;
 564                 sk->sk_error_report(sk);
 565         }
 566 }
 567
 568 static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
 569 {
 570         struct vhost_vsock *vsock = file->private_data;
 571
 572         spin_lock_bh(&vhost_vsock_lock);
 573         list_del(&vsock->list);
 574         spin_unlock_bh(&vhost_vsock_lock);
 575
 576         /* Iterating over all connections for all CIDs to find orphans is
 577          * inefficient.  Room for improvement here. */
 578         vsock_for_each_connected_socket(vhost_vsock_reset_orphans);
 579
 580         vhost_vsock_stop(vsock);
 581         vhost_vsock_flush(vsock);
 582         vhost_dev_stop(&vsock->dev);
 583
 584         spin_lock_bh(&vsock->send_pkt_list_lock);
 585         while (!list_empty(&vsock->send_pkt_list)) {
 586                 struct virtio_vsock_pkt *pkt;
 587
 588                 pkt = list_first_entry(&vsock->send_pkt_list,
 589                                 struct virtio_vsock_pkt, list);
 590                 list_del_init(&pkt->list);
 591                 virtio_transport_free_pkt(pkt);
 592         }
 593         spin_unlock_bh(&vsock->send_pkt_list_lock);
 594
 595         vhost_dev_cleanup(&vsock->dev, false);
 596         kfree(vsock->dev.vqs);
 597         vhost_vsock_free(vsock);
 598         return 0;
 599 }
 600
 601 static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
 602 {
 603         struct vhost_vsock *other;
 604
 605         /* Refuse reserved CIDs */
 606         if (guest_cid <= VMADDR_CID_HOST ||
 607             guest_cid == U32_MAX)
 608                 return -EINVAL;
 609
 610         /* 64-bit CIDs are not yet supported */
 611         if (guest_cid > U32_MAX)
 612                 return -EINVAL;
 613
 614         /* Refuse if CID is already in use */
 615         spin_lock_bh(&vhost_vsock_lock);
 616         other = __vhost_vsock_get(guest_cid);
 617         if (other && other != vsock) {
 618                 spin_unlock_bh(&vhost_vsock_lock);
 619                 return -EADDRINUSE;
 620         }
 621         vsock->guest_cid = guest_cid;
 622         spin_unlock_bh(&vhost_vsock_lock);
 623
 624         return 0;
 625 }
 626
 627 static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
 628 {
 629         struct vhost_virtqueue *vq;
 630         int i;
 631
 632         if (features & ~VHOST_VSOCK_FEATURES)
 633                 return -EOPNOTSUPP;
 634
 635         mutex_lock(&vsock->dev.mutex);
 636         if ((features & (1 << VHOST_F_LOG_ALL)) &&
 637             !vhost_log_access_ok(&vsock->dev)) {
 638                 mutex_unlock(&vsock->dev.mutex);
 639                 return -EFAULT;
 640         }
 641
 642         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 643                 vq = &vsock->vqs[i];
 644                 mutex_lock(&vq->mutex);
 645                 vq->acked_features = features;
 646                 mutex_unlock(&vq->mutex);
 647         }
 648         mutex_unlock(&vsock->dev.mutex);
 649         return 0;
 650 }
 651
 652 static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
 653                                   unsigned long arg)
 654 {
 655         struct vhost_vsock *vsock = f->private_data;
 656         void __user *argp = (void __user *)arg;
 657         u64 guest_cid;
 658         u64 features;
 659         int start;
 660         int r;
 661
 662         switch (ioctl) {
 663         case VHOST_VSOCK_SET_GUEST_CID:
 664                 if (copy_from_user(&guest_cid, argp, sizeof(guest_cid)))
 665                         return -EFAULT;
 666                 return vhost_vsock_set_cid(vsock, guest_cid);
 667         case VHOST_VSOCK_SET_RUNNING:
 668                 if (copy_from_user(&start, argp, sizeof(start)))
 669                         return -EFAULT;
 670                 if (start)
 671                         return vhost_vsock_start(vsock);
 672                 else
 673                         return vhost_vsock_stop(vsock);
 674         case VHOST_GET_FEATURES:
 675                 features = VHOST_VSOCK_FEATURES;
 676                 if (copy_to_user(argp, &features, sizeof(features)))
 677                         return -EFAULT;
 678                 return 0;
 679         case VHOST_SET_FEATURES:
 680                 if (copy_from_user(&features, argp, sizeof(features)))
 681                         return -EFAULT;
 682                 return vhost_vsock_set_features(vsock, features);
 683         default:
 684                 mutex_lock(&vsock->dev.mutex);
 685                 r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
 686                 if (r == -ENOIOCTLCMD)
 687                         r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
 688                 else
 689                         vhost_vsock_flush(vsock);
 690                 mutex_unlock(&vsock->dev.mutex);
 691                 return r;
 692         }
 693 }
 694
 695 static const struct file_operations vhost_vsock_fops = {
 696         .owner          = THIS_MODULE,
 697         .open           = vhost_vsock_dev_open,
 698         .release        = vhost_vsock_dev_release,
 699         .llseek         = noop_llseek,
 700         .unlocked_ioctl = vhost_vsock_dev_ioctl,
 701 };
 702
 703 static struct miscdevice vhost_vsock_misc = {
 704         .minor = MISC_DYNAMIC_MINOR,
 705         .name = "vhost-vsock",
 706         .fops = &vhost_vsock_fops,
 707 };
 708
 709 static struct virtio_transport vhost_transport = {
 710         .transport = {
 711                 .get_local_cid            = vhost_transport_get_local_cid,
 712
 713                 .init                     = virtio_transport_do_socket_init,
 714                 .destruct                 = virtio_transport_destruct,
 715                 .release                  = virtio_transport_release,
 716                 .connect                  = virtio_transport_connect,
 717                 .shutdown                 = virtio_transport_shutdown,
 718                 .cancel_pkt               = vhost_transport_cancel_pkt,
 719
 720                 .dgram_enqueue            = virtio_transport_dgram_enqueue,
 721                 .dgram_dequeue            = virtio_transport_dgram_dequeue,
 722                 .dgram_bind               = virtio_transport_dgram_bind,
 723                 .dgram_allow              = virtio_transport_dgram_allow,
 724
 725                 .stream_enqueue           = virtio_transport_stream_enqueue,
 726                 .stream_dequeue           = virtio_transport_stream_dequeue,
 727                 .stream_has_data          = virtio_transport_stream_has_data,
 728                 .stream_has_space         = virtio_transport_stream_has_space,
 729                 .stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
 730                 .stream_is_active         = virtio_transport_stream_is_active,
 731                 .stream_allow             = virtio_transport_stream_allow,
 732
 733                 .notify_poll_in           = virtio_transport_notify_poll_in,
 734                 .notify_poll_out          = virtio_transport_notify_poll_out,
 735                 .notify_recv_init         = virtio_transport_notify_recv_init,
 736                 .notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
 737                 .notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
 738                 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
 739                 .notify_send_init         = virtio_transport_notify_send_init,
 740                 .notify_send_pre_block    = virtio_transport_notify_send_pre_block,
 741                 .notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
 742                 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
 743
 744                 .set_buffer_size          = virtio_transport_set_buffer_size,
 745                 .set_min_buffer_size      = virtio_transport_set_min_buffer_size,
 746                 .set_max_buffer_size      = virtio_transport_set_max_buffer_size,
 747                 .get_buffer_size          = virtio_transport_get_buffer_size,
 748                 .get_min_buffer_size      = virtio_transport_get_min_buffer_size,
 749                 .get_max_buffer_size      = virtio_transport_get_max_buffer_size,
 750         },
 751
 752         .send_pkt = vhost_transport_send_pkt,
 753 };
 754
 755 static int __init vhost_vsock_init(void)
 756 {
 757         int ret;
 758
 759         ret = vsock_core_init(&vhost_transport.transport);
 760         if (ret < 0)
 761                 return ret;
 762         return misc_register(&vhost_vsock_misc);
 763 };
 764
 765 static void __exit vhost_vsock_exit(void)
 766 {
 767         misc_deregister(&vhost_vsock_misc);
 768         vsock_core_exit();
 769 };
 770
 771 module_init(vhost_vsock_init);
 772 module_exit(vhost_vsock_exit);
 773 MODULE_LICENSE("GPL v2");
 774 MODULE_AUTHOR("Asias He");
 775 MODULE_DESCRIPTION("vhost transport for vsock ");