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