net/vmw_vsock/virtio_transport.c

   1 /*
   2  * virtio 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  * Some of the code is take from Gerd Hoffmann <kraxel@redhat.com>'s
   9  * early virtio-vsock proof-of-concept bits.
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2.
  12  */
  13 #include <linux/spinlock.h>
  14 #include <linux/module.h>
  15 #include <linux/list.h>
  16 #include <linux/atomic.h>
  17 #include <linux/virtio.h>
  18 #include <linux/virtio_ids.h>
  19 #include <linux/virtio_config.h>
  20 #include <linux/virtio_vsock.h>
  21 #include <net/sock.h>
  22 #include <linux/mutex.h>
  23 #include <net/af_vsock.h>
  24
  25 static struct workqueue_struct *virtio_vsock_workqueue;
  26 static struct virtio_vsock *the_virtio_vsock;
  27 static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */
  28
  29 struct virtio_vsock {
  30         struct virtio_device *vdev;
  31         struct virtqueue *vqs[VSOCK_VQ_MAX];
  32
  33         /* Virtqueue processing is deferred to a workqueue */
  34         struct work_struct tx_work;
  35         struct work_struct rx_work;
  36         struct work_struct event_work;
  37
  38         /* The following fields are protected by tx_lock.  vqs[VSOCK_VQ_TX]
  39          * must be accessed with tx_lock held.
  40          */
  41         struct mutex tx_lock;
  42
  43         struct work_struct send_pkt_work;
  44         spinlock_t send_pkt_list_lock;
  45         struct list_head send_pkt_list;
  46
  47         struct work_struct loopback_work;
  48         spinlock_t loopback_list_lock; /* protects loopback_list */
  49         struct list_head loopback_list;
  50
  51         atomic_t queued_replies;
  52
  53         /* The following fields are protected by rx_lock.  vqs[VSOCK_VQ_RX]
  54          * must be accessed with rx_lock held.
  55          */
  56         struct mutex rx_lock;
  57         int rx_buf_nr;
  58         int rx_buf_max_nr;
  59
  60         /* The following fields are protected by event_lock.
  61          * vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held.
  62          */
  63         struct mutex event_lock;
  64         struct virtio_vsock_event event_list[8];
  65
  66         u32 guest_cid;
  67 };
  68
  69 static struct virtio_vsock *virtio_vsock_get(void)
  70 {
  71         return the_virtio_vsock;
  72 }
  73
  74 static u32 virtio_transport_get_local_cid(void)
  75 {
  76         struct virtio_vsock *vsock = virtio_vsock_get();
  77
  78         if (!vsock)
  79                 return VMADDR_CID_ANY;
  80
  81         return vsock->guest_cid;
  82 }
  83
  84 static void virtio_transport_loopback_work(struct work_struct *work)
  85 {
  86         struct virtio_vsock *vsock =
  87                 container_of(work, struct virtio_vsock, loopback_work);
  88         LIST_HEAD(pkts);
  89
  90         spin_lock_bh(&vsock->loopback_list_lock);
  91         list_splice_init(&vsock->loopback_list, &pkts);
  92         spin_unlock_bh(&vsock->loopback_list_lock);
  93
  94         mutex_lock(&vsock->rx_lock);
  95         while (!list_empty(&pkts)) {
  96                 struct virtio_vsock_pkt *pkt;
  97
  98                 pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list);
  99                 list_del_init(&pkt->list);
 100
 101                 virtio_transport_recv_pkt(pkt);
 102         }
 103         mutex_unlock(&vsock->rx_lock);
 104 }
 105
 106 static int virtio_transport_send_pkt_loopback(struct virtio_vsock *vsock,
 107                                               struct virtio_vsock_pkt *pkt)
 108 {
 109         int len = pkt->len;
 110
 111         spin_lock_bh(&vsock->loopback_list_lock);
 112         list_add_tail(&pkt->list, &vsock->loopback_list);
 113         spin_unlock_bh(&vsock->loopback_list_lock);
 114
 115         queue_work(virtio_vsock_workqueue, &vsock->loopback_work);
 116
 117         return len;
 118 }
 119
 120 static void
 121 virtio_transport_send_pkt_work(struct work_struct *work)
 122 {
 123         struct virtio_vsock *vsock =
 124                 container_of(work, struct virtio_vsock, send_pkt_work);
 125         struct virtqueue *vq;
 126         bool added = false;
 127         bool restart_rx = false;
 128
 129         mutex_lock(&vsock->tx_lock);
 130
 131         vq = vsock->vqs[VSOCK_VQ_TX];
 132
 133         for (;;) {
 134                 struct virtio_vsock_pkt *pkt;
 135                 struct scatterlist hdr, buf, *sgs[2];
 136                 int ret, in_sg = 0, out_sg = 0;
 137                 bool reply;
 138
 139                 spin_lock_bh(&vsock->send_pkt_list_lock);
 140                 if (list_empty(&vsock->send_pkt_list)) {
 141                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 142                         break;
 143                 }
 144
 145                 pkt = list_first_entry(&vsock->send_pkt_list,
 146                                        struct virtio_vsock_pkt, list);
 147                 list_del_init(&pkt->list);
 148                 spin_unlock_bh(&vsock->send_pkt_list_lock);
 149
 150                 virtio_transport_deliver_tap_pkt(pkt);
 151
 152                 reply = pkt->reply;
 153
 154                 sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
 155                 sgs[out_sg++] = &hdr;
 156                 if (pkt->buf) {
 157                         sg_init_one(&buf, pkt->buf, pkt->len);
 158                         sgs[out_sg++] = &buf;
 159                 }
 160
 161                 ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL);
 162                 /* Usually this means that there is no more space available in
 163                  * the vq
 164                  */
 165                 if (ret < 0) {
 166                         spin_lock_bh(&vsock->send_pkt_list_lock);
 167                         list_add(&pkt->list, &vsock->send_pkt_list);
 168                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 169                         break;
 170                 }
 171
 172                 if (reply) {
 173                         struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
 174                         int val;
 175
 176                         val = atomic_dec_return(&vsock->queued_replies);
 177
 178                         /* Do we now have resources to resume rx processing? */
 179                         if (val + 1 == virtqueue_get_vring_size(rx_vq))
 180                                 restart_rx = true;
 181                 }
 182
 183                 added = true;
 184         }
 185
 186         if (added)
 187                 virtqueue_kick(vq);
 188
 189         mutex_unlock(&vsock->tx_lock);
 190
 191         if (restart_rx)
 192                 queue_work(virtio_vsock_workqueue, &vsock->rx_work);
 193 }
 194
 195 static int
 196 virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
 197 {
 198         struct virtio_vsock *vsock;
 199         int len = pkt->len;
 200
 201         vsock = virtio_vsock_get();
 202         if (!vsock) {
 203                 virtio_transport_free_pkt(pkt);
 204                 return -ENODEV;
 205         }
 206
 207         if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid)
 208                 return virtio_transport_send_pkt_loopback(vsock, pkt);
 209
 210         if (pkt->reply)
 211                 atomic_inc(&vsock->queued_replies);
 212
 213         spin_lock_bh(&vsock->send_pkt_list_lock);
 214         list_add_tail(&pkt->list, &vsock->send_pkt_list);
 215         spin_unlock_bh(&vsock->send_pkt_list_lock);
 216
 217         queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
 218         return len;
 219 }
 220
 221 static int
 222 virtio_transport_cancel_pkt(struct vsock_sock *vsk)
 223 {
 224         struct virtio_vsock *vsock;
 225         struct virtio_vsock_pkt *pkt, *n;
 226         int cnt = 0;
 227         LIST_HEAD(freeme);
 228
 229         vsock = virtio_vsock_get();
 230         if (!vsock) {
 231                 return -ENODEV;
 232         }
 233
 234         spin_lock_bh(&vsock->send_pkt_list_lock);
 235         list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
 236                 if (pkt->vsk != vsk)
 237                         continue;
 238                 list_move(&pkt->list, &freeme);
 239         }
 240         spin_unlock_bh(&vsock->send_pkt_list_lock);
 241
 242         list_for_each_entry_safe(pkt, n, &freeme, list) {
 243                 if (pkt->reply)
 244                         cnt++;
 245                 list_del(&pkt->list);
 246                 virtio_transport_free_pkt(pkt);
 247         }
 248
 249         if (cnt) {
 250                 struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
 251                 int new_cnt;
 252
 253                 new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
 254                 if (new_cnt + cnt >= virtqueue_get_vring_size(rx_vq) &&
 255                     new_cnt < virtqueue_get_vring_size(rx_vq))
 256                         queue_work(virtio_vsock_workqueue, &vsock->rx_work);
 257         }
 258
 259         return 0;
 260 }
 261
 262 static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
 263 {
 264         int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
 265         struct virtio_vsock_pkt *pkt;
 266         struct scatterlist hdr, buf, *sgs[2];
 267         struct virtqueue *vq;
 268         int ret;
 269
 270         vq = vsock->vqs[VSOCK_VQ_RX];
 271
 272         do {
 273                 pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
 274                 if (!pkt)
 275                         break;
 276
 277                 pkt->buf = kmalloc(buf_len, GFP_KERNEL);
 278                 if (!pkt->buf) {
 279                         virtio_transport_free_pkt(pkt);
 280                         break;
 281                 }
 282
 283                 pkt->len = buf_len;
 284
 285                 sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
 286                 sgs[0] = &hdr;
 287
 288                 sg_init_one(&buf, pkt->buf, buf_len);
 289                 sgs[1] = &buf;
 290                 ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL);
 291                 if (ret) {
 292                         virtio_transport_free_pkt(pkt);
 293                         break;
 294                 }
 295                 vsock->rx_buf_nr++;
 296         } while (vq->num_free);
 297         if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
 298                 vsock->rx_buf_max_nr = vsock->rx_buf_nr;
 299         virtqueue_kick(vq);
 300 }
 301
 302 static void virtio_transport_tx_work(struct work_struct *work)
 303 {
 304         struct virtio_vsock *vsock =
 305                 container_of(work, struct virtio_vsock, tx_work);
 306         struct virtqueue *vq;
 307         bool added = false;
 308
 309         vq = vsock->vqs[VSOCK_VQ_TX];
 310         mutex_lock(&vsock->tx_lock);
 311         do {
 312                 struct virtio_vsock_pkt *pkt;
 313                 unsigned int len;
 314
 315                 virtqueue_disable_cb(vq);
 316                 while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
 317                         virtio_transport_free_pkt(pkt);
 318                         added = true;
 319                 }
 320         } while (!virtqueue_enable_cb(vq));
 321         mutex_unlock(&vsock->tx_lock);
 322
 323         if (added)
 324                 queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
 325 }
 326
 327 /* Is there space left for replies to rx packets? */
 328 static bool virtio_transport_more_replies(struct virtio_vsock *vsock)
 329 {
 330         struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX];
 331         int val;
 332
 333         smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
 334         val = atomic_read(&vsock->queued_replies);
 335
 336         return val < virtqueue_get_vring_size(vq);
 337 }
 338
 339 static void virtio_transport_rx_work(struct work_struct *work)
 340 {
 341         struct virtio_vsock *vsock =
 342                 container_of(work, struct virtio_vsock, rx_work);
 343         struct virtqueue *vq;
 344
 345         vq = vsock->vqs[VSOCK_VQ_RX];
 346
 347         mutex_lock(&vsock->rx_lock);
 348
 349         do {
 350                 virtqueue_disable_cb(vq);
 351                 for (;;) {
 352                         struct virtio_vsock_pkt *pkt;
 353                         unsigned int len;
 354
 355                         if (!virtio_transport_more_replies(vsock)) {
 356                                 /* Stop rx until the device processes already
 357                                  * pending replies.  Leave rx virtqueue
 358                                  * callbacks disabled.
 359                                  */
 360                                 goto out;
 361                         }
 362
 363                         pkt = virtqueue_get_buf(vq, &len);
 364                         if (!pkt) {
 365                                 break;
 366                         }
 367
 368                         vsock->rx_buf_nr--;
 369
 370                         /* Drop short/long packets */
 371                         if (unlikely(len < sizeof(pkt->hdr) ||
 372                                      len > sizeof(pkt->hdr) + pkt->len)) {
 373                                 virtio_transport_free_pkt(pkt);
 374                                 continue;
 375                         }
 376
 377                         pkt->len = len - sizeof(pkt->hdr);
 378                         virtio_transport_deliver_tap_pkt(pkt);
 379                         virtio_transport_recv_pkt(pkt);
 380                 }
 381         } while (!virtqueue_enable_cb(vq));
 382
 383 out:
 384         if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
 385                 virtio_vsock_rx_fill(vsock);
 386         mutex_unlock(&vsock->rx_lock);
 387 }
 388
 389 /* event_lock must be held */
 390 static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock,
 391                                        struct virtio_vsock_event *event)
 392 {
 393         struct scatterlist sg;
 394         struct virtqueue *vq;
 395
 396         vq = vsock->vqs[VSOCK_VQ_EVENT];
 397
 398         sg_init_one(&sg, event, sizeof(*event));
 399
 400         return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL);
 401 }
 402
 403 /* event_lock must be held */
 404 static void virtio_vsock_event_fill(struct virtio_vsock *vsock)
 405 {
 406         size_t i;
 407
 408         for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) {
 409                 struct virtio_vsock_event *event = &vsock->event_list[i];
 410
 411                 virtio_vsock_event_fill_one(vsock, event);
 412         }
 413
 414         virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
 415 }
 416
 417 static void virtio_vsock_reset_sock(struct sock *sk)
 418 {
 419         lock_sock(sk);
 420         sk->sk_state = TCP_CLOSE;
 421         sk->sk_err = ECONNRESET;
 422         sk->sk_error_report(sk);
 423         release_sock(sk);
 424 }
 425
 426 static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock)
 427 {
 428         struct virtio_device *vdev = vsock->vdev;
 429         __le64 guest_cid;
 430
 431         vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
 432                           &guest_cid, sizeof(guest_cid));
 433         vsock->guest_cid = le64_to_cpu(guest_cid);
 434 }
 435
 436 /* event_lock must be held */
 437 static void virtio_vsock_event_handle(struct virtio_vsock *vsock,
 438                                       struct virtio_vsock_event *event)
 439 {
 440         switch (le32_to_cpu(event->id)) {
 441         case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET:
 442                 virtio_vsock_update_guest_cid(vsock);
 443                 vsock_for_each_connected_socket(virtio_vsock_reset_sock);
 444                 break;
 445         }
 446 }
 447
 448 static void virtio_transport_event_work(struct work_struct *work)
 449 {
 450         struct virtio_vsock *vsock =
 451                 container_of(work, struct virtio_vsock, event_work);
 452         struct virtqueue *vq;
 453
 454         vq = vsock->vqs[VSOCK_VQ_EVENT];
 455
 456         mutex_lock(&vsock->event_lock);
 457
 458         do {
 459                 struct virtio_vsock_event *event;
 460                 unsigned int len;
 461
 462                 virtqueue_disable_cb(vq);
 463                 while ((event = virtqueue_get_buf(vq, &len)) != NULL) {
 464                         if (len == sizeof(*event))
 465                                 virtio_vsock_event_handle(vsock, event);
 466
 467                         virtio_vsock_event_fill_one(vsock, event);
 468                 }
 469         } while (!virtqueue_enable_cb(vq));
 470
 471         virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
 472
 473         mutex_unlock(&vsock->event_lock);
 474 }
 475
 476 static void virtio_vsock_event_done(struct virtqueue *vq)
 477 {
 478         struct virtio_vsock *vsock = vq->vdev->priv;
 479
 480         if (!vsock)
 481                 return;
 482         queue_work(virtio_vsock_workqueue, &vsock->event_work);
 483 }
 484
 485 static void virtio_vsock_tx_done(struct virtqueue *vq)
 486 {
 487         struct virtio_vsock *vsock = vq->vdev->priv;
 488
 489         if (!vsock)
 490                 return;
 491         queue_work(virtio_vsock_workqueue, &vsock->tx_work);
 492 }
 493
 494 static void virtio_vsock_rx_done(struct virtqueue *vq)
 495 {
 496         struct virtio_vsock *vsock = vq->vdev->priv;
 497
 498         if (!vsock)
 499                 return;
 500         queue_work(virtio_vsock_workqueue, &vsock->rx_work);
 501 }
 502
 503 static struct virtio_transport virtio_transport = {
 504         .transport = {
 505                 .get_local_cid            = virtio_transport_get_local_cid,
 506
 507                 .init                     = virtio_transport_do_socket_init,
 508                 .destruct                 = virtio_transport_destruct,
 509                 .release                  = virtio_transport_release,
 510                 .connect                  = virtio_transport_connect,
 511                 .shutdown                 = virtio_transport_shutdown,
 512                 .cancel_pkt               = virtio_transport_cancel_pkt,
 513
 514                 .dgram_bind               = virtio_transport_dgram_bind,
 515                 .dgram_dequeue            = virtio_transport_dgram_dequeue,
 516                 .dgram_enqueue            = virtio_transport_dgram_enqueue,
 517                 .dgram_allow              = virtio_transport_dgram_allow,
 518
 519                 .stream_dequeue           = virtio_transport_stream_dequeue,
 520                 .stream_enqueue           = virtio_transport_stream_enqueue,
 521                 .stream_has_data          = virtio_transport_stream_has_data,
 522                 .stream_has_space         = virtio_transport_stream_has_space,
 523                 .stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
 524                 .stream_is_active         = virtio_transport_stream_is_active,
 525                 .stream_allow             = virtio_transport_stream_allow,
 526
 527                 .notify_poll_in           = virtio_transport_notify_poll_in,
 528                 .notify_poll_out          = virtio_transport_notify_poll_out,
 529                 .notify_recv_init         = virtio_transport_notify_recv_init,
 530                 .notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
 531                 .notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
 532                 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
 533                 .notify_send_init         = virtio_transport_notify_send_init,
 534                 .notify_send_pre_block    = virtio_transport_notify_send_pre_block,
 535                 .notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
 536                 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
 537
 538                 .set_buffer_size          = virtio_transport_set_buffer_size,
 539                 .set_min_buffer_size      = virtio_transport_set_min_buffer_size,
 540                 .set_max_buffer_size      = virtio_transport_set_max_buffer_size,
 541                 .get_buffer_size          = virtio_transport_get_buffer_size,
 542                 .get_min_buffer_size      = virtio_transport_get_min_buffer_size,
 543                 .get_max_buffer_size      = virtio_transport_get_max_buffer_size,
 544         },
 545
 546         .send_pkt = virtio_transport_send_pkt,
 547 };
 548
 549 static int virtio_vsock_probe(struct virtio_device *vdev)
 550 {
 551         vq_callback_t *callbacks[] = {
 552                 virtio_vsock_rx_done,
 553                 virtio_vsock_tx_done,
 554                 virtio_vsock_event_done,
 555         };
 556         static const char * const names[] = {
 557                 "rx",
 558                 "tx",
 559                 "event",
 560         };
 561         struct virtio_vsock *vsock = NULL;
 562         int ret;
 563
 564         ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
 565         if (ret)
 566                 return ret;
 567
 568         /* Only one virtio-vsock device per guest is supported */
 569         if (the_virtio_vsock) {
 570                 ret = -EBUSY;
 571                 goto out;
 572         }
 573
 574         vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
 575         if (!vsock) {
 576                 ret = -ENOMEM;
 577                 goto out;
 578         }
 579
 580         vsock->vdev = vdev;
 581
 582         ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX,
 583                               vsock->vqs, callbacks, names,
 584                               NULL);
 585         if (ret < 0)
 586                 goto out;
 587
 588         virtio_vsock_update_guest_cid(vsock);
 589
 590         vsock->rx_buf_nr = 0;
 591         vsock->rx_buf_max_nr = 0;
 592         atomic_set(&vsock->queued_replies, 0);
 593
 594         vdev->priv = vsock;
 595         the_virtio_vsock = vsock;
 596         mutex_init(&vsock->tx_lock);
 597         mutex_init(&vsock->rx_lock);
 598         mutex_init(&vsock->event_lock);
 599         spin_lock_init(&vsock->send_pkt_list_lock);
 600         INIT_LIST_HEAD(&vsock->send_pkt_list);
 601         spin_lock_init(&vsock->loopback_list_lock);
 602         INIT_LIST_HEAD(&vsock->loopback_list);
 603         INIT_WORK(&vsock->rx_work, virtio_transport_rx_work);
 604         INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
 605         INIT_WORK(&vsock->event_work, virtio_transport_event_work);
 606         INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
 607         INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_work);
 608
 609         mutex_lock(&vsock->rx_lock);
 610         virtio_vsock_rx_fill(vsock);
 611         mutex_unlock(&vsock->rx_lock);
 612
 613         mutex_lock(&vsock->event_lock);
 614         virtio_vsock_event_fill(vsock);
 615         mutex_unlock(&vsock->event_lock);
 616
 617         mutex_unlock(&the_virtio_vsock_mutex);
 618         return 0;
 619
 620 out:
 621         kfree(vsock);
 622         mutex_unlock(&the_virtio_vsock_mutex);
 623         return ret;
 624 }
 625
 626 static void virtio_vsock_remove(struct virtio_device *vdev)
 627 {
 628         struct virtio_vsock *vsock = vdev->priv;
 629         struct virtio_vsock_pkt *pkt;
 630
 631         flush_work(&vsock->loopback_work);
 632         flush_work(&vsock->rx_work);
 633         flush_work(&vsock->tx_work);
 634         flush_work(&vsock->event_work);
 635         flush_work(&vsock->send_pkt_work);
 636
 637         /* Reset all connected sockets when the device disappear */
 638         vsock_for_each_connected_socket(virtio_vsock_reset_sock);
 639
 640         vdev->config->reset(vdev);
 641
 642         mutex_lock(&vsock->rx_lock);
 643         while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX])))
 644                 virtio_transport_free_pkt(pkt);
 645         mutex_unlock(&vsock->rx_lock);
 646
 647         mutex_lock(&vsock->tx_lock);
 648         while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
 649                 virtio_transport_free_pkt(pkt);
 650         mutex_unlock(&vsock->tx_lock);
 651
 652         spin_lock_bh(&vsock->send_pkt_list_lock);
 653         while (!list_empty(&vsock->send_pkt_list)) {
 654                 pkt = list_first_entry(&vsock->send_pkt_list,
 655                                        struct virtio_vsock_pkt, list);
 656                 list_del(&pkt->list);
 657                 virtio_transport_free_pkt(pkt);
 658         }
 659         spin_unlock_bh(&vsock->send_pkt_list_lock);
 660
 661         spin_lock_bh(&vsock->loopback_list_lock);
 662         while (!list_empty(&vsock->loopback_list)) {
 663                 pkt = list_first_entry(&vsock->loopback_list,
 664                                        struct virtio_vsock_pkt, list);
 665                 list_del(&pkt->list);
 666                 virtio_transport_free_pkt(pkt);
 667         }
 668         spin_unlock_bh(&vsock->loopback_list_lock);
 669
 670         mutex_lock(&the_virtio_vsock_mutex);
 671         the_virtio_vsock = NULL;
 672         mutex_unlock(&the_virtio_vsock_mutex);
 673
 674         vdev->config->del_vqs(vdev);
 675
 676         kfree(vsock);
 677 }
 678
 679 static struct virtio_device_id id_table[] = {
 680         { VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
 681         { 0 },
 682 };
 683
 684 static unsigned int features[] = {
 685 };
 686
 687 static struct virtio_driver virtio_vsock_driver = {
 688         .feature_table = features,
 689         .feature_table_size = ARRAY_SIZE(features),
 690         .driver.name = KBUILD_MODNAME,
 691         .driver.owner = THIS_MODULE,
 692         .id_table = id_table,
 693         .probe = virtio_vsock_probe,
 694         .remove = virtio_vsock_remove,
 695 };
 696
 697 static int __init virtio_vsock_init(void)
 698 {
 699         int ret;
 700
 701         virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0);
 702         if (!virtio_vsock_workqueue)
 703                 return -ENOMEM;
 704
 705         ret = vsock_core_init(&virtio_transport.transport);
 706         if (ret)
 707                 goto out_wq;
 708
 709         ret = register_virtio_driver(&virtio_vsock_driver);
 710         if (ret)
 711                 goto out_vci;
 712
 713         return 0;
 714
 715 out_vci:
 716         vsock_core_exit();
 717 out_wq:
 718         destroy_workqueue(virtio_vsock_workqueue);
 719         return ret;
 720 }
 721
 722 static void __exit virtio_vsock_exit(void)
 723 {
 724         unregister_virtio_driver(&virtio_vsock_driver);
 725         vsock_core_exit();
 726         destroy_workqueue(virtio_vsock_workqueue);
 727 }
 728
 729 module_init(virtio_vsock_init);
 730 module_exit(virtio_vsock_exit);
 731 MODULE_LICENSE("GPL v2");
 732 MODULE_AUTHOR("Asias He");
 733 MODULE_DESCRIPTION("virtio transport for vsock");
 734 MODULE_DEVICE_TABLE(virtio, id_table);