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->len = buf_len; 311 312 sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr)); 313 sgs[0] = &hdr; 314 315 sg_init_one(&buf, pkt->buf, buf_len); 316 sgs[1] = &buf; 317 ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL); 318 if (ret) { 319 virtio_transport_free_pkt(pkt); 320 break; 321 } 322 vsock->rx_buf_nr++; 323 } while (vq->num_free); 324 if (vsock->rx_buf_nr > vsock->rx_buf_max_nr) 325 vsock->rx_buf_max_nr = vsock->rx_buf_nr; 326 virtqueue_kick(vq); 327 } 328 329 static void virtio_transport_tx_work(struct work_struct *work) 330 { 331 struct virtio_vsock *vsock = 332 container_of(work, struct virtio_vsock, tx_work); 333 struct virtqueue *vq; 334 bool added = false; 335 336 vq = vsock->vqs[VSOCK_VQ_TX]; 337 mutex_lock(&vsock->tx_lock); 338 339 if (!vsock->tx_run) 340 goto out; 341 342 do { 343 struct virtio_vsock_pkt *pkt; 344 unsigned int len; 345 346 virtqueue_disable_cb(vq); 347 while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) { 348 virtio_transport_free_pkt(pkt); 349 added = true; 350 } 351 } while (!virtqueue_enable_cb(vq)); 352 353 out: 354 mutex_unlock(&vsock->tx_lock); 355 356 if (added) 357 queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work); 358 } 359 360 /* Is there space left for replies to rx packets? */ 361 static bool virtio_transport_more_replies(struct virtio_vsock *vsock) 362 { 363 struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX]; 364 int val; 365 366 smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */ 367 val = atomic_read(&vsock->queued_replies); 368 369 return val < virtqueue_get_vring_size(vq); 370 } 371 372 static void virtio_transport_rx_work(struct work_struct *work) 373 { 374 struct virtio_vsock *vsock = 375 container_of(work, struct virtio_vsock, rx_work); 376 struct virtqueue *vq; 377 378 vq = vsock->vqs[VSOCK_VQ_RX]; 379 380 mutex_lock(&vsock->rx_lock); 381 382 if (!vsock->rx_run) 383 goto out; 384 385 do { 386 virtqueue_disable_cb(vq); 387 for (;;) { 388 struct virtio_vsock_pkt *pkt; 389 unsigned int len; 390 391 if (!virtio_transport_more_replies(vsock)) { 392 /* Stop rx until the device processes already 393 * pending replies. Leave rx virtqueue 394 * callbacks disabled. 395 */ 396 goto out; 397 } 398 399 pkt = virtqueue_get_buf(vq, &len); 400 if (!pkt) { 401 break; 402 } 403 404 vsock->rx_buf_nr--; 405 406 /* Drop short/long packets */ 407 if (unlikely(len < sizeof(pkt->hdr) || 408 len > sizeof(pkt->hdr) + pkt->len)) { 409 virtio_transport_free_pkt(pkt); 410 continue; 411 } 412 413 pkt->len = len - sizeof(pkt->hdr); 414 virtio_transport_deliver_tap_pkt(pkt); 415 virtio_transport_recv_pkt(pkt); 416 } 417 } while (!virtqueue_enable_cb(vq)); 418 419 out: 420 if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2) 421 virtio_vsock_rx_fill(vsock); 422 mutex_unlock(&vsock->rx_lock); 423 } 424 425 /* event_lock must be held */ 426 static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock, 427 struct virtio_vsock_event *event) 428 { 429 struct scatterlist sg; 430 struct virtqueue *vq; 431 432 vq = vsock->vqs[VSOCK_VQ_EVENT]; 433 434 sg_init_one(&sg, event, sizeof(*event)); 435 436 return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL); 437 } 438 439 /* event_lock must be held */ 440 static void virtio_vsock_event_fill(struct virtio_vsock *vsock) 441 { 442 size_t i; 443 444 for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) { 445 struct virtio_vsock_event *event = &vsock->event_list[i]; 446 447 virtio_vsock_event_fill_one(vsock, event); 448 } 449 450 virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]); 451 } 452 453 static void virtio_vsock_reset_sock(struct sock *sk) 454 { 455 lock_sock(sk); 456 sk->sk_state = TCP_CLOSE; 457 sk->sk_err = ECONNRESET; 458 sk->sk_error_report(sk); 459 release_sock(sk); 460 } 461 462 static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock) 463 { 464 struct virtio_device *vdev = vsock->vdev; 465 __le64 guest_cid; 466 467 vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid), 468 &guest_cid, sizeof(guest_cid)); 469 vsock->guest_cid = le64_to_cpu(guest_cid); 470 } 471 472 /* event_lock must be held */ 473 static void virtio_vsock_event_handle(struct virtio_vsock *vsock, 474 struct virtio_vsock_event *event) 475 { 476 switch (le32_to_cpu(event->id)) { 477 case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET: 478 virtio_vsock_update_guest_cid(vsock); 479 vsock_for_each_connected_socket(virtio_vsock_reset_sock); 480 break; 481 } 482 } 483 484 static void virtio_transport_event_work(struct work_struct *work) 485 { 486 struct virtio_vsock *vsock = 487 container_of(work, struct virtio_vsock, event_work); 488 struct virtqueue *vq; 489 490 vq = vsock->vqs[VSOCK_VQ_EVENT]; 491 492 mutex_lock(&vsock->event_lock); 493 494 if (!vsock->event_run) 495 goto out; 496 497 do { 498 struct virtio_vsock_event *event; 499 unsigned int len; 500 501 virtqueue_disable_cb(vq); 502 while ((event = virtqueue_get_buf(vq, &len)) != NULL) { 503 if (len == sizeof(*event)) 504 virtio_vsock_event_handle(vsock, event); 505 506 virtio_vsock_event_fill_one(vsock, event); 507 } 508 } while (!virtqueue_enable_cb(vq)); 509 510 virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]); 511 out: 512 mutex_unlock(&vsock->event_lock); 513 } 514 515 static void virtio_vsock_event_done(struct virtqueue *vq) 516 { 517 struct virtio_vsock *vsock = vq->vdev->priv; 518 519 if (!vsock) 520 return; 521 queue_work(virtio_vsock_workqueue, &vsock->event_work); 522 } 523 524 static void virtio_vsock_tx_done(struct virtqueue *vq) 525 { 526 struct virtio_vsock *vsock = vq->vdev->priv; 527 528 if (!vsock) 529 return; 530 queue_work(virtio_vsock_workqueue, &vsock->tx_work); 531 } 532 533 static void virtio_vsock_rx_done(struct virtqueue *vq) 534 { 535 struct virtio_vsock *vsock = vq->vdev->priv; 536 537 if (!vsock) 538 return; 539 queue_work(virtio_vsock_workqueue, &vsock->rx_work); 540 } 541 542 static struct virtio_transport virtio_transport = { 543 .transport = { 544 .get_local_cid = virtio_transport_get_local_cid, 545 546 .init = virtio_transport_do_socket_init, 547 .destruct = virtio_transport_destruct, 548 .release = virtio_transport_release, 549 .connect = virtio_transport_connect, 550 .shutdown = virtio_transport_shutdown, 551 .cancel_pkt = virtio_transport_cancel_pkt, 552 553 .dgram_bind = virtio_transport_dgram_bind, 554 .dgram_dequeue = virtio_transport_dgram_dequeue, 555 .dgram_enqueue = virtio_transport_dgram_enqueue, 556 .dgram_allow = virtio_transport_dgram_allow, 557 558 .stream_dequeue = virtio_transport_stream_dequeue, 559 .stream_enqueue = virtio_transport_stream_enqueue, 560 .stream_has_data = virtio_transport_stream_has_data, 561 .stream_has_space = virtio_transport_stream_has_space, 562 .stream_rcvhiwat = virtio_transport_stream_rcvhiwat, 563 .stream_is_active = virtio_transport_stream_is_active, 564 .stream_allow = virtio_transport_stream_allow, 565 566 .notify_poll_in = virtio_transport_notify_poll_in, 567 .notify_poll_out = virtio_transport_notify_poll_out, 568 .notify_recv_init = virtio_transport_notify_recv_init, 569 .notify_recv_pre_block = virtio_transport_notify_recv_pre_block, 570 .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue, 571 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue, 572 .notify_send_init = virtio_transport_notify_send_init, 573 .notify_send_pre_block = virtio_transport_notify_send_pre_block, 574 .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, 575 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, 576 577 .set_buffer_size = virtio_transport_set_buffer_size, 578 .set_min_buffer_size = virtio_transport_set_min_buffer_size, 579 .set_max_buffer_size = virtio_transport_set_max_buffer_size, 580 .get_buffer_size = virtio_transport_get_buffer_size, 581 .get_min_buffer_size = virtio_transport_get_min_buffer_size, 582 .get_max_buffer_size = virtio_transport_get_max_buffer_size, 583 }, 584 585 .send_pkt = virtio_transport_send_pkt, 586 }; 587 588 static int virtio_vsock_probe(struct virtio_device *vdev) 589 { 590 vq_callback_t *callbacks[] = { 591 virtio_vsock_rx_done, 592 virtio_vsock_tx_done, 593 virtio_vsock_event_done, 594 }; 595 static const char * const names[] = { 596 "rx", 597 "tx", 598 "event", 599 }; 600 struct virtio_vsock *vsock = NULL; 601 int ret; 602 603 ret = mutex_lock_interruptible(&the_virtio_vsock_mutex); 604 if (ret) 605 return ret; 606 607 /* Only one virtio-vsock device per guest is supported */ 608 if (rcu_dereference_protected(the_virtio_vsock, 609 lockdep_is_held(&the_virtio_vsock_mutex))) { 610 ret = -EBUSY; 611 goto out; 612 } 613 614 vsock = kzalloc(sizeof(*vsock), GFP_KERNEL); 615 if (!vsock) { 616 ret = -ENOMEM; 617 goto out; 618 } 619 620 vsock->vdev = vdev; 621 622 ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX, 623 vsock->vqs, callbacks, names, 624 NULL); 625 if (ret < 0) 626 goto out; 627 628 virtio_vsock_update_guest_cid(vsock); 629 630 vsock->rx_buf_nr = 0; 631 vsock->rx_buf_max_nr = 0; 632 atomic_set(&vsock->queued_replies, 0); 633 634 mutex_init(&vsock->tx_lock); 635 mutex_init(&vsock->rx_lock); 636 mutex_init(&vsock->event_lock); 637 spin_lock_init(&vsock->send_pkt_list_lock); 638 INIT_LIST_HEAD(&vsock->send_pkt_list); 639 spin_lock_init(&vsock->loopback_list_lock); 640 INIT_LIST_HEAD(&vsock->loopback_list); 641 INIT_WORK(&vsock->rx_work, virtio_transport_rx_work); 642 INIT_WORK(&vsock->tx_work, virtio_transport_tx_work); 643 INIT_WORK(&vsock->event_work, virtio_transport_event_work); 644 INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work); 645 INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_work); 646 647 mutex_lock(&vsock->tx_lock); 648 vsock->tx_run = true; 649 mutex_unlock(&vsock->tx_lock); 650 651 mutex_lock(&vsock->rx_lock); 652 virtio_vsock_rx_fill(vsock); 653 vsock->rx_run = true; 654 mutex_unlock(&vsock->rx_lock); 655 656 mutex_lock(&vsock->event_lock); 657 virtio_vsock_event_fill(vsock); 658 vsock->event_run = true; 659 mutex_unlock(&vsock->event_lock); 660 661 vdev->priv = vsock; 662 rcu_assign_pointer(the_virtio_vsock, vsock); 663 664 mutex_unlock(&the_virtio_vsock_mutex); 665 return 0; 666 667 out: 668 kfree(vsock); 669 mutex_unlock(&the_virtio_vsock_mutex); 670 return ret; 671 } 672 673 static void virtio_vsock_remove(struct virtio_device *vdev) 674 { 675 struct virtio_vsock *vsock = vdev->priv; 676 struct virtio_vsock_pkt *pkt; 677 678 mutex_lock(&the_virtio_vsock_mutex); 679 680 vdev->priv = NULL; 681 rcu_assign_pointer(the_virtio_vsock, NULL); 682 synchronize_rcu(); 683 684 /* Reset all connected sockets when the device disappear */ 685 vsock_for_each_connected_socket(virtio_vsock_reset_sock); 686 687 /* Stop all work handlers to make sure no one is accessing the device, 688 * so we can safely call vdev->config->reset(). 689 */ 690 mutex_lock(&vsock->rx_lock); 691 vsock->rx_run = false; 692 mutex_unlock(&vsock->rx_lock); 693 694 mutex_lock(&vsock->tx_lock); 695 vsock->tx_run = false; 696 mutex_unlock(&vsock->tx_lock); 697 698 mutex_lock(&vsock->event_lock); 699 vsock->event_run = false; 700 mutex_unlock(&vsock->event_lock); 701 702 /* Flush all device writes and interrupts, device will not use any 703 * more buffers. 704 */ 705 vdev->config->reset(vdev); 706 707 mutex_lock(&vsock->rx_lock); 708 while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX]))) 709 virtio_transport_free_pkt(pkt); 710 mutex_unlock(&vsock->rx_lock); 711 712 mutex_lock(&vsock->tx_lock); 713 while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX]))) 714 virtio_transport_free_pkt(pkt); 715 mutex_unlock(&vsock->tx_lock); 716 717 spin_lock_bh(&vsock->send_pkt_list_lock); 718 while (!list_empty(&vsock->send_pkt_list)) { 719 pkt = list_first_entry(&vsock->send_pkt_list, 720 struct virtio_vsock_pkt, list); 721 list_del(&pkt->list); 722 virtio_transport_free_pkt(pkt); 723 } 724 spin_unlock_bh(&vsock->send_pkt_list_lock); 725 726 spin_lock_bh(&vsock->loopback_list_lock); 727 while (!list_empty(&vsock->loopback_list)) { 728 pkt = list_first_entry(&vsock->loopback_list, 729 struct virtio_vsock_pkt, list); 730 list_del(&pkt->list); 731 virtio_transport_free_pkt(pkt); 732 } 733 spin_unlock_bh(&vsock->loopback_list_lock); 734 735 /* Delete virtqueues and flush outstanding callbacks if any */ 736 vdev->config->del_vqs(vdev); 737 738 /* Other works can be queued before 'config->del_vqs()', so we flush 739 * all works before to free the vsock object to avoid use after free. 740 */ 741 flush_work(&vsock->loopback_work); 742 flush_work(&vsock->rx_work); 743 flush_work(&vsock->tx_work); 744 flush_work(&vsock->event_work); 745 flush_work(&vsock->send_pkt_work); 746 747 mutex_unlock(&the_virtio_vsock_mutex); 748 749 kfree(vsock); 750 } 751 752 static struct virtio_device_id id_table[] = { 753 { VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID }, 754 { 0 }, 755 }; 756 757 static unsigned int features[] = { 758 }; 759 760 static struct virtio_driver virtio_vsock_driver = { 761 .feature_table = features, 762 .feature_table_size = ARRAY_SIZE(features), 763 .driver.name = KBUILD_MODNAME, 764 .driver.owner = THIS_MODULE, 765 .id_table = id_table, 766 .probe = virtio_vsock_probe, 767 .remove = virtio_vsock_remove, 768 }; 769 770 static int __init virtio_vsock_init(void) 771 { 772 int ret; 773 774 virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0); 775 if (!virtio_vsock_workqueue) 776 return -ENOMEM; 777 778 ret = vsock_core_init(&virtio_transport.transport); 779 if (ret) 780 goto out_wq; 781 782 ret = register_virtio_driver(&virtio_vsock_driver); 783 if (ret) 784 goto out_vci; 785 786 return 0; 787 788 out_vci: 789 vsock_core_exit(); 790 out_wq: 791 destroy_workqueue(virtio_vsock_workqueue); 792 return ret; 793 } 794 795 static void __exit virtio_vsock_exit(void) 796 { 797 unregister_virtio_driver(&virtio_vsock_driver); 798 vsock_core_exit(); 799 destroy_workqueue(virtio_vsock_workqueue); 800 } 801 802 module_init(virtio_vsock_init); 803 module_exit(virtio_vsock_exit); 804 MODULE_LICENSE("GPL v2"); 805 MODULE_AUTHOR("Asias He"); 806 MODULE_DESCRIPTION("virtio transport for vsock"); 807 MODULE_DEVICE_TABLE(virtio, id_table); 808