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                 reply = pkt->reply;
 148
 149                 sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
 150                 sgs[out_sg++] = &hdr;
 151                 if (pkt->buf) {
 152                         sg_init_one(&buf, pkt->buf, pkt->len);
 153                         sgs[out_sg++] = &buf;
 154                 }
 155
 156                 ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL);
 157                 /* Usually this means that there is no more space available in
 158                  * the vq
 159                  */
 160                 if (ret < 0) {
 161                         spin_lock_bh(&vsock->send_pkt_list_lock);
 162                         list_add(&pkt->list, &vsock->send_pkt_list);
 163                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 164                         break;
 165                 }
 166
 167                 if (reply) {
 168                         struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
 169                         int val;
 170
 171                         val = atomic_dec_return(&vsock->queued_replies);
 172
 173                         /* Do we now have resources to resume rx processing? */
 174                         if (val + 1 == virtqueue_get_vring_size(rx_vq))
 175                                 restart_rx = true;
 176                 }
 177
 178                 added = true;
 179         }
 180
 181         if (added)
 182                 virtqueue_kick(vq);
 183
 184         mutex_unlock(&vsock->tx_lock);
 185
 186         if (restart_rx)
 187                 queue_work(virtio_vsock_workqueue, &vsock->rx_work);
 188 }
 189
 190 static int
 191 virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
 192 {
 193         struct virtio_vsock *vsock;
 194         int len = pkt->len;
 195
 196         vsock = virtio_vsock_get();
 197         if (!vsock) {
 198                 virtio_transport_free_pkt(pkt);
 199                 return -ENODEV;
 200         }
 201
 202         if (le32_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid)
 203                 return virtio_transport_send_pkt_loopback(vsock, pkt);
 204
 205         if (pkt->reply)
 206                 atomic_inc(&vsock->queued_replies);
 207
 208         spin_lock_bh(&vsock->send_pkt_list_lock);
 209         list_add_tail(&pkt->list, &vsock->send_pkt_list);
 210         spin_unlock_bh(&vsock->send_pkt_list_lock);
 211
 212         queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
 213         return len;
 214 }
 215
 216 static int
 217 virtio_transport_cancel_pkt(struct vsock_sock *vsk)
 218 {
 219         struct virtio_vsock *vsock;
 220         struct virtio_vsock_pkt *pkt, *n;
 221         int cnt = 0;
 222         LIST_HEAD(freeme);
 223
 224         vsock = virtio_vsock_get();
 225         if (!vsock) {
 226                 return -ENODEV;
 227         }
 228
 229         spin_lock_bh(&vsock->send_pkt_list_lock);
 230         list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
 231                 if (pkt->vsk != vsk)
 232                         continue;
 233                 list_move(&pkt->list, &freeme);
 234         }
 235         spin_unlock_bh(&vsock->send_pkt_list_lock);
 236
 237         list_for_each_entry_safe(pkt, n, &freeme, list) {
 238                 if (pkt->reply)
 239                         cnt++;
 240                 list_del(&pkt->list);
 241                 virtio_transport_free_pkt(pkt);
 242         }
 243
 244         if (cnt) {
 245                 struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
 246                 int new_cnt;
 247
 248                 new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
 249                 if (new_cnt + cnt >= virtqueue_get_vring_size(rx_vq) &&
 250                     new_cnt < virtqueue_get_vring_size(rx_vq))
 251                         queue_work(virtio_vsock_workqueue, &vsock->rx_work);
 252         }
 253
 254         return 0;
 255 }
 256
 257 static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
 258 {
 259         int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
 260         struct virtio_vsock_pkt *pkt;
 261         struct scatterlist hdr, buf, *sgs[2];
 262         struct virtqueue *vq;
 263         int ret;
 264
 265         vq = vsock->vqs[VSOCK_VQ_RX];
 266
 267         do {
 268                 pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
 269                 if (!pkt)
 270                         break;
 271
 272                 pkt->buf = kmalloc(buf_len, GFP_KERNEL);
 273                 if (!pkt->buf) {
 274                         virtio_transport_free_pkt(pkt);
 275                         break;
 276                 }
 277
 278                 pkt->len = buf_len;
 279
 280                 sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
 281                 sgs[0] = &hdr;
 282
 283                 sg_init_one(&buf, pkt->buf, buf_len);
 284                 sgs[1] = &buf;
 285                 ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL);
 286                 if (ret) {
 287                         virtio_transport_free_pkt(pkt);
 288                         break;
 289                 }
 290                 vsock->rx_buf_nr++;
 291         } while (vq->num_free);
 292         if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
 293                 vsock->rx_buf_max_nr = vsock->rx_buf_nr;
 294         virtqueue_kick(vq);
 295 }
 296
 297 static void virtio_transport_tx_work(struct work_struct *work)
 298 {
 299         struct virtio_vsock *vsock =
 300                 container_of(work, struct virtio_vsock, tx_work);
 301         struct virtqueue *vq;
 302         bool added = false;
 303
 304         vq = vsock->vqs[VSOCK_VQ_TX];
 305         mutex_lock(&vsock->tx_lock);
 306         do {
 307                 struct virtio_vsock_pkt *pkt;
 308                 unsigned int len;
 309
 310                 virtqueue_disable_cb(vq);
 311                 while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
 312                         virtio_transport_free_pkt(pkt);
 313                         added = true;
 314                 }
 315         } while (!virtqueue_enable_cb(vq));
 316         mutex_unlock(&vsock->tx_lock);
 317
 318         if (added)
 319                 queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
 320 }
 321
 322 /* Is there space left for replies to rx packets? */
 323 static bool virtio_transport_more_replies(struct virtio_vsock *vsock)
 324 {
 325         struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX];
 326         int val;
 327
 328         smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
 329         val = atomic_read(&vsock->queued_replies);
 330
 331         return val < virtqueue_get_vring_size(vq);
 332 }
 333
 334 static void virtio_transport_rx_work(struct work_struct *work)
 335 {
 336         struct virtio_vsock *vsock =
 337                 container_of(work, struct virtio_vsock, rx_work);
 338         struct virtqueue *vq;
 339
 340         vq = vsock->vqs[VSOCK_VQ_RX];
 341
 342         mutex_lock(&vsock->rx_lock);
 343
 344         do {
 345                 virtqueue_disable_cb(vq);
 346                 for (;;) {
 347                         struct virtio_vsock_pkt *pkt;
 348                         unsigned int len;
 349
 350                         if (!virtio_transport_more_replies(vsock)) {
 351                                 /* Stop rx until the device processes already
 352                                  * pending replies.  Leave rx virtqueue
 353                                  * callbacks disabled.
 354                                  */
 355                                 goto out;
 356                         }
 357
 358                         pkt = virtqueue_get_buf(vq, &len);
 359                         if (!pkt) {
 360                                 break;
 361                         }
 362
 363                         vsock->rx_buf_nr--;
 364
 365                         /* Drop short/long packets */
 366                         if (unlikely(len < sizeof(pkt->hdr) ||
 367                                      len > sizeof(pkt->hdr) + pkt->len)) {
 368                                 virtio_transport_free_pkt(pkt);
 369                                 continue;
 370                         }
 371
 372                         pkt->len = len - sizeof(pkt->hdr);
 373                         virtio_transport_recv_pkt(pkt);
 374                 }
 375         } while (!virtqueue_enable_cb(vq));
 376
 377 out:
 378         if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
 379                 virtio_vsock_rx_fill(vsock);
 380         mutex_unlock(&vsock->rx_lock);
 381 }
 382
 383 /* event_lock must be held */
 384 static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock,
 385                                        struct virtio_vsock_event *event)
 386 {
 387         struct scatterlist sg;
 388         struct virtqueue *vq;
 389
 390         vq = vsock->vqs[VSOCK_VQ_EVENT];
 391
 392         sg_init_one(&sg, event, sizeof(*event));
 393
 394         return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL);
 395 }
 396
 397 /* event_lock must be held */
 398 static void virtio_vsock_event_fill(struct virtio_vsock *vsock)
 399 {
 400         size_t i;
 401
 402         for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) {
 403                 struct virtio_vsock_event *event = &vsock->event_list[i];
 404
 405                 virtio_vsock_event_fill_one(vsock, event);
 406         }
 407
 408         virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
 409 }
 410
 411 static void virtio_vsock_reset_sock(struct sock *sk)
 412 {
 413         lock_sock(sk);
 414         sk->sk_state = SS_UNCONNECTED;
 415         sk->sk_err = ECONNRESET;
 416         sk->sk_error_report(sk);
 417         release_sock(sk);
 418 }
 419
 420 static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock)
 421 {
 422         struct virtio_device *vdev = vsock->vdev;
 423         __le64 guest_cid;
 424
 425         vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
 426                           &guest_cid, sizeof(guest_cid));
 427         vsock->guest_cid = le64_to_cpu(guest_cid);
 428 }
 429
 430 /* event_lock must be held */
 431 static void virtio_vsock_event_handle(struct virtio_vsock *vsock,
 432                                       struct virtio_vsock_event *event)
 433 {
 434         switch (le32_to_cpu(event->id)) {
 435         case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET:
 436                 virtio_vsock_update_guest_cid(vsock);
 437                 vsock_for_each_connected_socket(virtio_vsock_reset_sock);
 438                 break;
 439         }
 440 }
 441
 442 static void virtio_transport_event_work(struct work_struct *work)
 443 {
 444         struct virtio_vsock *vsock =
 445                 container_of(work, struct virtio_vsock, event_work);
 446         struct virtqueue *vq;
 447
 448         vq = vsock->vqs[VSOCK_VQ_EVENT];
 449
 450         mutex_lock(&vsock->event_lock);
 451
 452         do {
 453                 struct virtio_vsock_event *event;
 454                 unsigned int len;
 455
 456                 virtqueue_disable_cb(vq);
 457                 while ((event = virtqueue_get_buf(vq, &len)) != NULL) {
 458                         if (len == sizeof(*event))
 459                                 virtio_vsock_event_handle(vsock, event);
 460
 461                         virtio_vsock_event_fill_one(vsock, event);
 462                 }
 463         } while (!virtqueue_enable_cb(vq));
 464
 465         virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
 466
 467         mutex_unlock(&vsock->event_lock);
 468 }
 469
 470 static void virtio_vsock_event_done(struct virtqueue *vq)
 471 {
 472         struct virtio_vsock *vsock = vq->vdev->priv;
 473
 474         if (!vsock)
 475                 return;
 476         queue_work(virtio_vsock_workqueue, &vsock->event_work);
 477 }
 478
 479 static void virtio_vsock_tx_done(struct virtqueue *vq)
 480 {
 481         struct virtio_vsock *vsock = vq->vdev->priv;
 482
 483         if (!vsock)
 484                 return;
 485         queue_work(virtio_vsock_workqueue, &vsock->tx_work);
 486 }
 487
 488 static void virtio_vsock_rx_done(struct virtqueue *vq)
 489 {
 490         struct virtio_vsock *vsock = vq->vdev->priv;
 491
 492         if (!vsock)
 493                 return;
 494         queue_work(virtio_vsock_workqueue, &vsock->rx_work);
 495 }
 496
 497 static struct virtio_transport virtio_transport = {
 498         .transport = {
 499                 .get_local_cid            = virtio_transport_get_local_cid,
 500
 501                 .init                     = virtio_transport_do_socket_init,
 502                 .destruct                 = virtio_transport_destruct,
 503                 .release                  = virtio_transport_release,
 504                 .connect                  = virtio_transport_connect,
 505                 .shutdown                 = virtio_transport_shutdown,
 506                 .cancel_pkt               = virtio_transport_cancel_pkt,
 507
 508                 .dgram_bind               = virtio_transport_dgram_bind,
 509                 .dgram_dequeue            = virtio_transport_dgram_dequeue,
 510                 .dgram_enqueue            = virtio_transport_dgram_enqueue,
 511                 .dgram_allow              = virtio_transport_dgram_allow,
 512
 513                 .stream_dequeue           = virtio_transport_stream_dequeue,
 514                 .stream_enqueue           = virtio_transport_stream_enqueue,
 515                 .stream_has_data          = virtio_transport_stream_has_data,
 516                 .stream_has_space         = virtio_transport_stream_has_space,
 517                 .stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
 518                 .stream_is_active         = virtio_transport_stream_is_active,
 519                 .stream_allow             = virtio_transport_stream_allow,
 520
 521                 .notify_poll_in           = virtio_transport_notify_poll_in,
 522                 .notify_poll_out          = virtio_transport_notify_poll_out,
 523                 .notify_recv_init         = virtio_transport_notify_recv_init,
 524                 .notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
 525                 .notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
 526                 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
 527                 .notify_send_init         = virtio_transport_notify_send_init,
 528                 .notify_send_pre_block    = virtio_transport_notify_send_pre_block,
 529                 .notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
 530                 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
 531
 532                 .set_buffer_size          = virtio_transport_set_buffer_size,
 533                 .set_min_buffer_size      = virtio_transport_set_min_buffer_size,
 534                 .set_max_buffer_size      = virtio_transport_set_max_buffer_size,
 535                 .get_buffer_size          = virtio_transport_get_buffer_size,
 536                 .get_min_buffer_size      = virtio_transport_get_min_buffer_size,
 537                 .get_max_buffer_size      = virtio_transport_get_max_buffer_size,
 538         },
 539
 540         .send_pkt = virtio_transport_send_pkt,
 541 };
 542
 543 static int virtio_vsock_probe(struct virtio_device *vdev)
 544 {
 545         vq_callback_t *callbacks[] = {
 546                 virtio_vsock_rx_done,
 547                 virtio_vsock_tx_done,
 548                 virtio_vsock_event_done,
 549         };
 550         static const char * const names[] = {
 551                 "rx",
 552                 "tx",
 553                 "event",
 554         };
 555         struct virtio_vsock *vsock = NULL;
 556         int ret;
 557
 558         ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
 559         if (ret)
 560                 return ret;
 561
 562         /* Only one virtio-vsock device per guest is supported */
 563         if (the_virtio_vsock) {
 564                 ret = -EBUSY;
 565                 goto out;
 566         }
 567
 568         vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
 569         if (!vsock) {
 570                 ret = -ENOMEM;
 571                 goto out;
 572         }
 573
 574         vsock->vdev = vdev;
 575
 576         ret = vsock->vdev->config->find_vqs(vsock->vdev, VSOCK_VQ_MAX,
 577                                             vsock->vqs, callbacks, names,
 578                                             NULL);
 579         if (ret < 0)
 580                 goto out;
 581
 582         virtio_vsock_update_guest_cid(vsock);
 583
 584         ret = vsock_core_init(&virtio_transport.transport);
 585         if (ret < 0)
 586                 goto out_vqs;
 587
 588         vsock->rx_buf_nr = 0;
 589         vsock->rx_buf_max_nr = 0;
 590         atomic_set(&vsock->queued_replies, 0);
 591
 592         vdev->priv = vsock;
 593         the_virtio_vsock = vsock;
 594         mutex_init(&vsock->tx_lock);
 595         mutex_init(&vsock->rx_lock);
 596         mutex_init(&vsock->event_lock);
 597         spin_lock_init(&vsock->send_pkt_list_lock);
 598         INIT_LIST_HEAD(&vsock->send_pkt_list);
 599         spin_lock_init(&vsock->loopback_list_lock);
 600         INIT_LIST_HEAD(&vsock->loopback_list);
 601         INIT_WORK(&vsock->rx_work, virtio_transport_rx_work);
 602         INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
 603         INIT_WORK(&vsock->event_work, virtio_transport_event_work);
 604         INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
 605         INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_work);
 606
 607         mutex_lock(&vsock->rx_lock);
 608         virtio_vsock_rx_fill(vsock);
 609         mutex_unlock(&vsock->rx_lock);
 610
 611         mutex_lock(&vsock->event_lock);
 612         virtio_vsock_event_fill(vsock);
 613         mutex_unlock(&vsock->event_lock);
 614
 615         mutex_unlock(&the_virtio_vsock_mutex);
 616         return 0;
 617
 618 out_vqs:
 619         vsock->vdev->config->del_vqs(vsock->vdev);
 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         vdev->config->reset(vdev);
 638
 639         mutex_lock(&vsock->rx_lock);
 640         while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX])))
 641                 virtio_transport_free_pkt(pkt);
 642         mutex_unlock(&vsock->rx_lock);
 643
 644         mutex_lock(&vsock->tx_lock);
 645         while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
 646                 virtio_transport_free_pkt(pkt);
 647         mutex_unlock(&vsock->tx_lock);
 648
 649         spin_lock_bh(&vsock->send_pkt_list_lock);
 650         while (!list_empty(&vsock->send_pkt_list)) {
 651                 pkt = list_first_entry(&vsock->send_pkt_list,
 652                                        struct virtio_vsock_pkt, list);
 653                 list_del(&pkt->list);
 654                 virtio_transport_free_pkt(pkt);
 655         }
 656         spin_unlock_bh(&vsock->send_pkt_list_lock);
 657
 658         spin_lock_bh(&vsock->loopback_list_lock);
 659         while (!list_empty(&vsock->loopback_list)) {
 660                 pkt = list_first_entry(&vsock->loopback_list,
 661                                        struct virtio_vsock_pkt, list);
 662                 list_del(&pkt->list);
 663                 virtio_transport_free_pkt(pkt);
 664         }
 665         spin_unlock_bh(&vsock->loopback_list_lock);
 666
 667         mutex_lock(&the_virtio_vsock_mutex);
 668         the_virtio_vsock = NULL;
 669         vsock_core_exit();
 670         mutex_unlock(&the_virtio_vsock_mutex);
 671
 672         vdev->config->del_vqs(vdev);
 673
 674         kfree(vsock);
 675 }
 676
 677 static struct virtio_device_id id_table[] = {
 678         { VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
 679         { 0 },
 680 };
 681
 682 static unsigned int features[] = {
 683 };
 684
 685 static struct virtio_driver virtio_vsock_driver = {
 686         .feature_table = features,
 687         .feature_table_size = ARRAY_SIZE(features),
 688         .driver.name = KBUILD_MODNAME,
 689         .driver.owner = THIS_MODULE,
 690         .id_table = id_table,
 691         .probe = virtio_vsock_probe,
 692         .remove = virtio_vsock_remove,
 693 };
 694
 695 static int __init virtio_vsock_init(void)
 696 {
 697         int ret;
 698
 699         virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0);
 700         if (!virtio_vsock_workqueue)
 701                 return -ENOMEM;
 702         ret = register_virtio_driver(&virtio_vsock_driver);
 703         if (ret)
 704                 destroy_workqueue(virtio_vsock_workqueue);
 705         return ret;
 706 }
 707
 708 static void __exit virtio_vsock_exit(void)
 709 {
 710         unregister_virtio_driver(&virtio_vsock_driver);
 711         destroy_workqueue(virtio_vsock_workqueue);
 712 }
 713
 714 module_init(virtio_vsock_init);
 715 module_exit(virtio_vsock_exit);
 716 MODULE_LICENSE("GPL v2");
 717 MODULE_AUTHOR("Asias He");
 718 MODULE_DESCRIPTION("virtio transport for vsock");
 719 MODULE_DEVICE_TABLE(virtio, id_table);