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