1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * virtio transport for vsock 4 * 5 * Copyright (C) 2013-2015 Red Hat, Inc. 6 * Author: Asias He <asias@redhat.com> 7 * Stefan Hajnoczi <stefanha@redhat.com> 8 * 9 * Some of the code is take from Gerd Hoffmann <kraxel@redhat.com>'s 10 * early virtio-vsock proof-of-concept bits. 11 */ 12 #include <linux/spinlock.h> 13 #include <linux/module.h> 14 #include <linux/list.h> 15 #include <linux/atomic.h> 16 #include <linux/virtio.h> 17 #include <linux/virtio_ids.h> 18 #include <linux/virtio_config.h> 19 #include <linux/virtio_vsock.h> 20 #include <net/sock.h> 21 #include <linux/mutex.h> 22 #include <net/af_vsock.h> 23 24 static struct workqueue_struct *virtio_vsock_workqueue; 25 static struct virtio_vsock *the_virtio_vsock; 26 static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */ 27 28 struct virtio_vsock { 29 struct virtio_device *vdev; 30 struct virtqueue *vqs[VSOCK_VQ_MAX]; 31 32 /* Virtqueue processing is deferred to a workqueue */ 33 struct work_struct tx_work; 34 struct work_struct rx_work; 35 struct work_struct event_work; 36 37 /* The following fields are protected by tx_lock. vqs[VSOCK_VQ_TX] 38 * must be accessed with tx_lock held. 39 */ 40 struct mutex tx_lock; 41 bool tx_run; 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 bool rx_run; 58 int rx_buf_nr; 59 int rx_buf_max_nr; 60 61 /* The following fields are protected by event_lock. 62 * vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held. 63 */ 64 struct mutex event_lock; 65 bool event_run; 66 struct virtio_vsock_event event_list[8]; 67 68 u32 guest_cid; 69 }; 70 71 static u32 virtio_transport_get_local_cid(void) 72 { 73 struct virtio_vsock *vsock; 74 u32 ret; 75 76 rcu_read_lock(); 77 vsock = rcu_dereference(the_virtio_vsock); 78 if (!vsock) { 79 ret = VMADDR_CID_ANY; 80 goto out_rcu; 81 } 82 83 ret = vsock->guest_cid; 84 out_rcu: 85 rcu_read_unlock(); 86 return ret; 87 } 88 89 static void virtio_transport_loopback_work(struct work_struct *work) 90 { 91 struct virtio_vsock *vsock = 92 container_of(work, struct virtio_vsock, loopback_work); 93 LIST_HEAD(pkts); 94 95 spin_lock_bh(&vsock->loopback_list_lock); 96 list_splice_init(&vsock->loopback_list, &pkts); 97 spin_unlock_bh(&vsock->loopback_list_lock); 98 99 mutex_lock(&vsock->rx_lock); 100 101 if (!vsock->rx_run) 102 goto out; 103 104 while (!list_empty(&pkts)) { 105 struct virtio_vsock_pkt *pkt; 106 107 pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list); 108 list_del_init(&pkt->list); 109 110 virtio_transport_recv_pkt(pkt); 111 } 112 out: 113 mutex_unlock(&vsock->rx_lock); 114 } 115 116 static int virtio_transport_send_pkt_loopback(struct virtio_vsock *vsock, 117 struct virtio_vsock_pkt *pkt) 118 { 119 int len = pkt->len; 120 121 spin_lock_bh(&vsock->loopback_list_lock); 122 list_add_tail(&pkt->list, &vsock->loopback_list); 123 spin_unlock_bh(&vsock->loopback_list_lock); 124 125 queue_work(virtio_vsock_workqueue, &vsock->loopback_work); 126 127 return len; 128 } 129 130 static void 131 virtio_transport_send_pkt_work(struct work_struct *work) 132 { 133 struct virtio_vsock *vsock = 134 container_of(work, struct virtio_vsock, send_pkt_work); 135 struct virtqueue *vq; 136 bool added = false; 137 bool restart_rx = false; 138 139 mutex_lock(&vsock->tx_lock); 140 141 if (!vsock->tx_run) 142 goto out; 143 144 vq = vsock->vqs[VSOCK_VQ_TX]; 145 146 for (;;) { 147 struct virtio_vsock_pkt *pkt; 148 struct scatterlist hdr, buf, *sgs[2]; 149 int ret, in_sg = 0, out_sg = 0; 150 bool reply; 151 152 spin_lock_bh(&vsock->send_pkt_list_lock); 153 if (list_empty(&vsock->send_pkt_list)) { 154 spin_unlock_bh(&vsock->send_pkt_list_lock); 155 break; 156 } 157 158 pkt = list_first_entry(&vsock->send_pkt_list, 159 struct virtio_vsock_pkt, list); 160 list_del_init(&pkt->list); 161 spin_unlock_bh(&vsock->send_pkt_list_lock); 162 163 virtio_transport_deliver_tap_pkt(pkt); 164 165 reply = pkt->reply; 166 167 sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr)); 168 sgs[out_sg++] = &hdr; 169 if (pkt->buf) { 170 sg_init_one(&buf, pkt->buf, pkt->len); 171 sgs[out_sg++] = &buf; 172 } 173 174 ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL); 175 /* Usually this means that there is no more space available in 176 * the vq 177 */ 178 if (ret < 0) { 179 spin_lock_bh(&vsock->send_pkt_list_lock); 180 list_add(&pkt->list, &vsock->send_pkt_list); 181 spin_unlock_bh(&vsock->send_pkt_list_lock); 182 break; 183 } 184 185 if (reply) { 186 struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX]; 187 int val; 188 189 val = atomic_dec_return(&vsock->queued_replies); 190 191 /* Do we now have resources to resume rx processing? */ 192 if (val + 1 == virtqueue_get_vring_size(rx_vq)) 193 restart_rx = true; 194 } 195 196 added = true; 197 } 198 199 if (added) 200 virtqueue_kick(vq); 201 202 out: 203 mutex_unlock(&vsock->tx_lock); 204 205 if (restart_rx) 206 queue_work(virtio_vsock_workqueue, &vsock->rx_work); 207 } 208 209 static int 210 virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt) 211 { 212 struct virtio_vsock *vsock; 213 int len = pkt->len; 214 215 rcu_read_lock(); 216 vsock = rcu_dereference(the_virtio_vsock); 217 if (!vsock) { 218 virtio_transport_free_pkt(pkt); 219 len = -ENODEV; 220 goto out_rcu; 221 } 222 223 if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid) { 224 len = virtio_transport_send_pkt_loopback(vsock, pkt); 225 goto out_rcu; 226 } 227 228 if (pkt->reply) 229 atomic_inc(&vsock->queued_replies); 230 231 spin_lock_bh(&vsock->send_pkt_list_lock); 232 list_add_tail(&pkt->list, &vsock->send_pkt_list); 233 spin_unlock_bh(&vsock->send_pkt_list_lock); 234 235 queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work); 236 237 out_rcu: 238 rcu_read_unlock(); 239 return len; 240 } 241 242 static int 243 virtio_transport_cancel_pkt(struct vsock_sock *vsk) 244 { 245 struct virtio_vsock *vsock; 246 struct virtio_vsock_pkt *pkt, *n; 247 int cnt = 0, ret; 248 LIST_HEAD(freeme); 249 250 rcu_read_lock(); 251 vsock = rcu_dereference(the_virtio_vsock); 252 if (!vsock) { 253 ret = -ENODEV; 254 goto out_rcu; 255 } 256 257 spin_lock_bh(&vsock->send_pkt_list_lock); 258 list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) { 259 if (pkt->vsk != vsk) 260 continue; 261 list_move(&pkt->list, &freeme); 262 } 263 spin_unlock_bh(&vsock->send_pkt_list_lock); 264 265 list_for_each_entry_safe(pkt, n, &freeme, list) { 266 if (pkt->reply) 267 cnt++; 268 list_del(&pkt->list); 269 virtio_transport_free_pkt(pkt); 270 } 271 272 if (cnt) { 273 struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX]; 274 int new_cnt; 275 276 new_cnt = atomic_sub_return(cnt, &vsock->queued_replies); 277 if (new_cnt + cnt >= virtqueue_get_vring_size(rx_vq) && 278 new_cnt < virtqueue_get_vring_size(rx_vq)) 279 queue_work(virtio_vsock_workqueue, &vsock->rx_work); 280 } 281 282 ret = 0; 283 284 out_rcu: 285 rcu_read_unlock(); 286 return ret; 287 } 288 289 static void virtio_vsock_rx_fill(struct virtio_vsock *vsock) 290 { 291 int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; 292 struct virtio_vsock_pkt *pkt; 293 struct scatterlist hdr, buf, *sgs[2]; 294 struct virtqueue *vq; 295 int ret; 296 297 vq = vsock->vqs[VSOCK_VQ_RX]; 298 299 do { 300 pkt = kzalloc(sizeof(*pkt), GFP_KERNEL); 301 if (!pkt) 302 break; 303 304 pkt->buf = kmalloc(buf_len, GFP_KERNEL); 305 if (!pkt->buf) { 306 virtio_transport_free_pkt(pkt); 307 break; 308 } 309 310 pkt->buf_len = buf_len; 311 pkt->len = buf_len; 312 313 sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr)); 314 sgs[0] = &hdr; 315 316 sg_init_one(&buf, pkt->buf, buf_len); 317 sgs[1] = &buf; 318 ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL); 319 if (ret) { 320 virtio_transport_free_pkt(pkt); 321 break; 322 } 323 vsock->rx_buf_nr++; 324 } while (vq->num_free); 325 if (vsock->rx_buf_nr > vsock->rx_buf_max_nr) 326 vsock->rx_buf_max_nr = vsock->rx_buf_nr; 327 virtqueue_kick(vq); 328 } 329 330 static void virtio_transport_tx_work(struct work_struct *work) 331 { 332 struct virtio_vsock *vsock = 333 container_of(work, struct virtio_vsock, tx_work); 334 struct virtqueue *vq; 335 bool added = false; 336 337 vq = vsock->vqs[VSOCK_VQ_TX]; 338 mutex_lock(&vsock->tx_lock); 339 340 if (!vsock->tx_run) 341 goto out; 342 343 do { 344 struct virtio_vsock_pkt *pkt; 345 unsigned int len; 346 347 virtqueue_disable_cb(vq); 348 while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) { 349 virtio_transport_free_pkt(pkt); 350 added = true; 351 } 352 } while (!virtqueue_enable_cb(vq)); 353 354 out: 355 mutex_unlock(&vsock->tx_lock); 356 357 if (added) 358 queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work); 359 } 360 361 /* Is there space left for replies to rx packets? */ 362 static bool virtio_transport_more_replies(struct virtio_vsock *vsock) 363 { 364 struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX]; 365 int val; 366 367 smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */ 368 val = atomic_read(&vsock->queued_replies); 369 370 return val < virtqueue_get_vring_size(vq); 371 } 372 373 static void virtio_transport_rx_work(struct work_struct *work) 374 { 375 struct virtio_vsock *vsock = 376 container_of(work, struct virtio_vsock, rx_work); 377 struct virtqueue *vq; 378 379 vq = vsock->vqs[VSOCK_VQ_RX]; 380 381 mutex_lock(&vsock->rx_lock); 382 383 if (!vsock->rx_run) 384 goto out; 385 386 do { 387 virtqueue_disable_cb(vq); 388 for (;;) { 389 struct virtio_vsock_pkt *pkt; 390 unsigned int len; 391 392 if (!virtio_transport_more_replies(vsock)) { 393 /* Stop rx until the device processes already 394 * pending replies. Leave rx virtqueue 395 * callbacks disabled. 396 */ 397 goto out; 398 } 399 400 pkt = virtqueue_get_buf(vq, &len); 401 if (!pkt) { 402 break; 403 } 404 405 vsock->rx_buf_nr--; 406 407 /* Drop short/long packets */ 408 if (unlikely(len < sizeof(pkt->hdr) || 409 len > sizeof(pkt->hdr) + pkt->len)) { 410 virtio_transport_free_pkt(pkt); 411 continue; 412 } 413 414 pkt->len = len - sizeof(pkt->hdr); 415 virtio_transport_deliver_tap_pkt(pkt); 416 virtio_transport_recv_pkt(pkt); 417 } 418 } while (!virtqueue_enable_cb(vq)); 419 420 out: 421 if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2) 422 virtio_vsock_rx_fill(vsock); 423 mutex_unlock(&vsock->rx_lock); 424 } 425 426 /* event_lock must be held */ 427 static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock, 428 struct virtio_vsock_event *event) 429 { 430 struct scatterlist sg; 431 struct virtqueue *vq; 432 433 vq = vsock->vqs[VSOCK_VQ_EVENT]; 434 435 sg_init_one(&sg, event, sizeof(*event)); 436 437 return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL); 438 } 439 440 /* event_lock must be held */ 441 static void virtio_vsock_event_fill(struct virtio_vsock *vsock) 442 { 443 size_t i; 444 445 for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) { 446 struct virtio_vsock_event *event = &vsock->event_list[i]; 447 448 virtio_vsock_event_fill_one(vsock, event); 449 } 450 451 virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]); 452 } 453 454 static void virtio_vsock_reset_sock(struct sock *sk) 455 { 456 lock_sock(sk); 457 sk->sk_state = TCP_CLOSE; 458 sk->sk_err = ECONNRESET; 459 sk->sk_error_report(sk); 460 release_sock(sk); 461 } 462 463 static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock) 464 { 465 struct virtio_device *vdev = vsock->vdev; 466 __le64 guest_cid; 467 468 vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid), 469 &guest_cid, sizeof(guest_cid)); 470 vsock->guest_cid = le64_to_cpu(guest_cid); 471 } 472 473 /* event_lock must be held */ 474 static void virtio_vsock_event_handle(struct virtio_vsock *vsock, 475 struct virtio_vsock_event *event) 476 { 477 switch (le32_to_cpu(event->id)) { 478 case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET: 479 virtio_vsock_update_guest_cid(vsock); 480 vsock_for_each_connected_socket(virtio_vsock_reset_sock); 481 break; 482 } 483 } 484 485 static void virtio_transport_event_work(struct work_struct *work) 486 { 487 struct virtio_vsock *vsock = 488 container_of(work, struct virtio_vsock, event_work); 489 struct virtqueue *vq; 490 491 vq = vsock->vqs[VSOCK_VQ_EVENT]; 492 493 mutex_lock(&vsock->event_lock); 494 495 if (!vsock->event_run) 496 goto out; 497 498 do { 499 struct virtio_vsock_event *event; 500 unsigned int len; 501 502 virtqueue_disable_cb(vq); 503 while ((event = virtqueue_get_buf(vq, &len)) != NULL) { 504 if (len == sizeof(*event)) 505 virtio_vsock_event_handle(vsock, event); 506 507 virtio_vsock_event_fill_one(vsock, event); 508 } 509 } while (!virtqueue_enable_cb(vq)); 510 511 virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]); 512 out: 513 mutex_unlock(&vsock->event_lock); 514 } 515 516 static void virtio_vsock_event_done(struct virtqueue *vq) 517 { 518 struct virtio_vsock *vsock = vq->vdev->priv; 519 520 if (!vsock) 521 return; 522 queue_work(virtio_vsock_workqueue, &vsock->event_work); 523 } 524 525 static void virtio_vsock_tx_done(struct virtqueue *vq) 526 { 527 struct virtio_vsock *vsock = vq->vdev->priv; 528 529 if (!vsock) 530 return; 531 queue_work(virtio_vsock_workqueue, &vsock->tx_work); 532 } 533 534 static void virtio_vsock_rx_done(struct virtqueue *vq) 535 { 536 struct virtio_vsock *vsock = vq->vdev->priv; 537 538 if (!vsock) 539 return; 540 queue_work(virtio_vsock_workqueue, &vsock->rx_work); 541 } 542 543 static struct virtio_transport virtio_transport = { 544 .transport = { 545 .get_local_cid = virtio_transport_get_local_cid, 546 547 .init = virtio_transport_do_socket_init, 548 .destruct = virtio_transport_destruct, 549 .release = virtio_transport_release, 550 .connect = virtio_transport_connect, 551 .shutdown = virtio_transport_shutdown, 552 .cancel_pkt = virtio_transport_cancel_pkt, 553 554 .dgram_bind = virtio_transport_dgram_bind, 555 .dgram_dequeue = virtio_transport_dgram_dequeue, 556 .dgram_enqueue = virtio_transport_dgram_enqueue, 557 .dgram_allow = virtio_transport_dgram_allow, 558 559 .stream_dequeue = virtio_transport_stream_dequeue, 560 .stream_enqueue = virtio_transport_stream_enqueue, 561 .stream_has_data = virtio_transport_stream_has_data, 562 .stream_has_space = virtio_transport_stream_has_space, 563 .stream_rcvhiwat = virtio_transport_stream_rcvhiwat, 564 .stream_is_active = virtio_transport_stream_is_active, 565 .stream_allow = virtio_transport_stream_allow, 566 567 .notify_poll_in = virtio_transport_notify_poll_in, 568 .notify_poll_out = virtio_transport_notify_poll_out, 569 .notify_recv_init = virtio_transport_notify_recv_init, 570 .notify_recv_pre_block = virtio_transport_notify_recv_pre_block, 571 .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue, 572 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue, 573 .notify_send_init = virtio_transport_notify_send_init, 574 .notify_send_pre_block = virtio_transport_notify_send_pre_block, 575 .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, 576 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, 577 578 .set_buffer_size = virtio_transport_set_buffer_size, 579 .set_min_buffer_size = virtio_transport_set_min_buffer_size, 580 .set_max_buffer_size = virtio_transport_set_max_buffer_size, 581 .get_buffer_size = virtio_transport_get_buffer_size, 582 .get_min_buffer_size = virtio_transport_get_min_buffer_size, 583 .get_max_buffer_size = virtio_transport_get_max_buffer_size, 584 }, 585 586 .send_pkt = virtio_transport_send_pkt, 587 }; 588 589 static int virtio_vsock_probe(struct virtio_device *vdev) 590 { 591 vq_callback_t *callbacks[] = { 592 virtio_vsock_rx_done, 593 virtio_vsock_tx_done, 594 virtio_vsock_event_done, 595 }; 596 static const char * const names[] = { 597 "rx", 598 "tx", 599 "event", 600 }; 601 struct virtio_vsock *vsock = NULL; 602 int ret; 603 604 ret = mutex_lock_interruptible(&the_virtio_vsock_mutex); 605 if (ret) 606 return ret; 607 608 /* Only one virtio-vsock device per guest is supported */ 609 if (rcu_dereference_protected(the_virtio_vsock, 610 lockdep_is_held(&the_virtio_vsock_mutex))) { 611 ret = -EBUSY; 612 goto out; 613 } 614 615 vsock = kzalloc(sizeof(*vsock), GFP_KERNEL); 616 if (!vsock) { 617 ret = -ENOMEM; 618 goto out; 619 } 620 621 vsock->vdev = vdev; 622 623 ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX, 624 vsock->vqs, callbacks, names, 625 NULL); 626 if (ret < 0) 627 goto out; 628 629 virtio_vsock_update_guest_cid(vsock); 630 631 vsock->rx_buf_nr = 0; 632 vsock->rx_buf_max_nr = 0; 633 atomic_set(&vsock->queued_replies, 0); 634 635 mutex_init(&vsock->tx_lock); 636 mutex_init(&vsock->rx_lock); 637 mutex_init(&vsock->event_lock); 638 spin_lock_init(&vsock->send_pkt_list_lock); 639 INIT_LIST_HEAD(&vsock->send_pkt_list); 640 spin_lock_init(&vsock->loopback_list_lock); 641 INIT_LIST_HEAD(&vsock->loopback_list); 642 INIT_WORK(&vsock->rx_work, virtio_transport_rx_work); 643 INIT_WORK(&vsock->tx_work, virtio_transport_tx_work); 644 INIT_WORK(&vsock->event_work, virtio_transport_event_work); 645 INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work); 646 INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_work); 647 648 mutex_lock(&vsock->tx_lock); 649 vsock->tx_run = true; 650 mutex_unlock(&vsock->tx_lock); 651 652 mutex_lock(&vsock->rx_lock); 653 virtio_vsock_rx_fill(vsock); 654 vsock->rx_run = true; 655 mutex_unlock(&vsock->rx_lock); 656 657 mutex_lock(&vsock->event_lock); 658 virtio_vsock_event_fill(vsock); 659 vsock->event_run = true; 660 mutex_unlock(&vsock->event_lock); 661 662 vdev->priv = vsock; 663 rcu_assign_pointer(the_virtio_vsock, vsock); 664 665 mutex_unlock(&the_virtio_vsock_mutex); 666 return 0; 667 668 out: 669 kfree(vsock); 670 mutex_unlock(&the_virtio_vsock_mutex); 671 return ret; 672 } 673 674 static void virtio_vsock_remove(struct virtio_device *vdev) 675 { 676 struct virtio_vsock *vsock = vdev->priv; 677 struct virtio_vsock_pkt *pkt; 678 679 mutex_lock(&the_virtio_vsock_mutex); 680 681 vdev->priv = NULL; 682 rcu_assign_pointer(the_virtio_vsock, NULL); 683 synchronize_rcu(); 684 685 /* Reset all connected sockets when the device disappear */ 686 vsock_for_each_connected_socket(virtio_vsock_reset_sock); 687 688 /* Stop all work handlers to make sure no one is accessing the device, 689 * so we can safely call vdev->config->reset(). 690 */ 691 mutex_lock(&vsock->rx_lock); 692 vsock->rx_run = false; 693 mutex_unlock(&vsock->rx_lock); 694 695 mutex_lock(&vsock->tx_lock); 696 vsock->tx_run = false; 697 mutex_unlock(&vsock->tx_lock); 698 699 mutex_lock(&vsock->event_lock); 700 vsock->event_run = false; 701 mutex_unlock(&vsock->event_lock); 702 703 /* Flush all device writes and interrupts, device will not use any 704 * more buffers. 705 */ 706 vdev->config->reset(vdev); 707 708 mutex_lock(&vsock->rx_lock); 709 while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX]))) 710 virtio_transport_free_pkt(pkt); 711 mutex_unlock(&vsock->rx_lock); 712 713 mutex_lock(&vsock->tx_lock); 714 while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX]))) 715 virtio_transport_free_pkt(pkt); 716 mutex_unlock(&vsock->tx_lock); 717 718 spin_lock_bh(&vsock->send_pkt_list_lock); 719 while (!list_empty(&vsock->send_pkt_list)) { 720 pkt = list_first_entry(&vsock->send_pkt_list, 721 struct virtio_vsock_pkt, list); 722 list_del(&pkt->list); 723 virtio_transport_free_pkt(pkt); 724 } 725 spin_unlock_bh(&vsock->send_pkt_list_lock); 726 727 spin_lock_bh(&vsock->loopback_list_lock); 728 while (!list_empty(&vsock->loopback_list)) { 729 pkt = list_first_entry(&vsock->loopback_list, 730 struct virtio_vsock_pkt, list); 731 list_del(&pkt->list); 732 virtio_transport_free_pkt(pkt); 733 } 734 spin_unlock_bh(&vsock->loopback_list_lock); 735 736 /* Delete virtqueues and flush outstanding callbacks if any */ 737 vdev->config->del_vqs(vdev); 738 739 /* Other works can be queued before 'config->del_vqs()', so we flush 740 * all works before to free the vsock object to avoid use after free. 741 */ 742 flush_work(&vsock->loopback_work); 743 flush_work(&vsock->rx_work); 744 flush_work(&vsock->tx_work); 745 flush_work(&vsock->event_work); 746 flush_work(&vsock->send_pkt_work); 747 748 mutex_unlock(&the_virtio_vsock_mutex); 749 750 kfree(vsock); 751 } 752 753 static struct virtio_device_id id_table[] = { 754 { VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID }, 755 { 0 }, 756 }; 757 758 static unsigned int features[] = { 759 }; 760 761 static struct virtio_driver virtio_vsock_driver = { 762 .feature_table = features, 763 .feature_table_size = ARRAY_SIZE(features), 764 .driver.name = KBUILD_MODNAME, 765 .driver.owner = THIS_MODULE, 766 .id_table = id_table, 767 .probe = virtio_vsock_probe, 768 .remove = virtio_vsock_remove, 769 }; 770 771 static int __init virtio_vsock_init(void) 772 { 773 int ret; 774 775 virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0); 776 if (!virtio_vsock_workqueue) 777 return -ENOMEM; 778 779 ret = vsock_core_init(&virtio_transport.transport); 780 if (ret) 781 goto out_wq; 782 783 ret = register_virtio_driver(&virtio_vsock_driver); 784 if (ret) 785 goto out_vci; 786 787 return 0; 788 789 out_vci: 790 vsock_core_exit(); 791 out_wq: 792 destroy_workqueue(virtio_vsock_workqueue); 793 return ret; 794 } 795 796 static void __exit virtio_vsock_exit(void) 797 { 798 unregister_virtio_driver(&virtio_vsock_driver); 799 vsock_core_exit(); 800 destroy_workqueue(virtio_vsock_workqueue); 801 } 802 803 module_init(virtio_vsock_init); 804 module_exit(virtio_vsock_exit); 805 MODULE_LICENSE("GPL v2"); 806 MODULE_AUTHOR("Asias He"); 807 MODULE_DESCRIPTION("virtio transport for vsock"); 808 MODULE_DEVICE_TABLE(virtio, id_table); 809