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 __rcu *the_virtio_vsock;
26 static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */
27 static struct virtio_transport virtio_transport; /* forward declaration */
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 bool tx_run;
43
44 struct work_struct send_pkt_work;
45 spinlock_t send_pkt_list_lock;
46 struct list_head send_pkt_list;
47
48 atomic_t queued_replies;
49
50 /* The following fields are protected by rx_lock. vqs[VSOCK_VQ_RX]
51 * must be accessed with rx_lock held.
52 */
53 struct mutex rx_lock;
54 bool rx_run;
55 int rx_buf_nr;
56 int rx_buf_max_nr;
57
58 /* The following fields are protected by event_lock.
59 * vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held.
60 */
61 struct mutex event_lock;
62 bool event_run;
63 struct virtio_vsock_event event_list[8];
64
65 u32 guest_cid;
66 };
67
virtio_transport_get_local_cid(void)68 static u32 virtio_transport_get_local_cid(void)
69 {
70 struct virtio_vsock *vsock;
71 u32 ret;
72
73 rcu_read_lock();
74 vsock = rcu_dereference(the_virtio_vsock);
75 if (!vsock) {
76 ret = VMADDR_CID_ANY;
77 goto out_rcu;
78 }
79
80 ret = vsock->guest_cid;
81 out_rcu:
82 rcu_read_unlock();
83 return ret;
84 }
85
86 static void
virtio_transport_send_pkt_work(struct work_struct * work)87 virtio_transport_send_pkt_work(struct work_struct *work)
88 {
89 struct virtio_vsock *vsock =
90 container_of(work, struct virtio_vsock, send_pkt_work);
91 struct virtqueue *vq;
92 bool added = false;
93 bool restart_rx = false;
94
95 mutex_lock(&vsock->tx_lock);
96
97 if (!vsock->tx_run)
98 goto out;
99
100 vq = vsock->vqs[VSOCK_VQ_TX];
101
102 for (;;) {
103 struct virtio_vsock_pkt *pkt;
104 struct scatterlist hdr, buf, *sgs[2];
105 int ret, in_sg = 0, out_sg = 0;
106 bool reply;
107
108 spin_lock_bh(&vsock->send_pkt_list_lock);
109 if (list_empty(&vsock->send_pkt_list)) {
110 spin_unlock_bh(&vsock->send_pkt_list_lock);
111 break;
112 }
113
114 pkt = list_first_entry(&vsock->send_pkt_list,
115 struct virtio_vsock_pkt, list);
116 list_del_init(&pkt->list);
117 spin_unlock_bh(&vsock->send_pkt_list_lock);
118
119 virtio_transport_deliver_tap_pkt(pkt);
120
121 reply = pkt->reply;
122
123 sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
124 sgs[out_sg++] = &hdr;
125 if (pkt->buf) {
126 sg_init_one(&buf, pkt->buf, pkt->len);
127 sgs[out_sg++] = &buf;
128 }
129
130 ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL);
131 /* Usually this means that there is no more space available in
132 * the vq
133 */
134 if (ret < 0) {
135 spin_lock_bh(&vsock->send_pkt_list_lock);
136 list_add(&pkt->list, &vsock->send_pkt_list);
137 spin_unlock_bh(&vsock->send_pkt_list_lock);
138 break;
139 }
140
141 if (reply) {
142 struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
143 int val;
144
145 val = atomic_dec_return(&vsock->queued_replies);
146
147 /* Do we now have resources to resume rx processing? */
148 if (val + 1 == virtqueue_get_vring_size(rx_vq))
149 restart_rx = true;
150 }
151
152 added = true;
153 }
154
155 if (added)
156 virtqueue_kick(vq);
157
158 out:
159 mutex_unlock(&vsock->tx_lock);
160
161 if (restart_rx)
162 queue_work(virtio_vsock_workqueue, &vsock->rx_work);
163 }
164
165 static int
virtio_transport_send_pkt(struct virtio_vsock_pkt * pkt)166 virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
167 {
168 struct virtio_vsock *vsock;
169 int len = pkt->len;
170
171 rcu_read_lock();
172 vsock = rcu_dereference(the_virtio_vsock);
173 if (!vsock) {
174 virtio_transport_free_pkt(pkt);
175 len = -ENODEV;
176 goto out_rcu;
177 }
178
179 if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid) {
180 virtio_transport_free_pkt(pkt);
181 len = -ENODEV;
182 goto out_rcu;
183 }
184
185 if (pkt->reply)
186 atomic_inc(&vsock->queued_replies);
187
188 spin_lock_bh(&vsock->send_pkt_list_lock);
189 list_add_tail(&pkt->list, &vsock->send_pkt_list);
190 spin_unlock_bh(&vsock->send_pkt_list_lock);
191
192 queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
193
194 out_rcu:
195 rcu_read_unlock();
196 return len;
197 }
198
199 static int
virtio_transport_cancel_pkt(struct vsock_sock * vsk)200 virtio_transport_cancel_pkt(struct vsock_sock *vsk)
201 {
202 struct virtio_vsock *vsock;
203 struct virtio_vsock_pkt *pkt, *n;
204 int cnt = 0, ret;
205 LIST_HEAD(freeme);
206
207 rcu_read_lock();
208 vsock = rcu_dereference(the_virtio_vsock);
209 if (!vsock) {
210 ret = -ENODEV;
211 goto out_rcu;
212 }
213
214 spin_lock_bh(&vsock->send_pkt_list_lock);
215 list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
216 if (pkt->vsk != vsk)
217 continue;
218 list_move(&pkt->list, &freeme);
219 }
220 spin_unlock_bh(&vsock->send_pkt_list_lock);
221
222 list_for_each_entry_safe(pkt, n, &freeme, list) {
223 if (pkt->reply)
224 cnt++;
225 list_del(&pkt->list);
226 virtio_transport_free_pkt(pkt);
227 }
228
229 if (cnt) {
230 struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
231 int new_cnt;
232
233 new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
234 if (new_cnt + cnt >= virtqueue_get_vring_size(rx_vq) &&
235 new_cnt < virtqueue_get_vring_size(rx_vq))
236 queue_work(virtio_vsock_workqueue, &vsock->rx_work);
237 }
238
239 ret = 0;
240
241 out_rcu:
242 rcu_read_unlock();
243 return ret;
244 }
245
virtio_vsock_rx_fill(struct virtio_vsock * vsock)246 static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
247 {
248 int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
249 struct virtio_vsock_pkt *pkt;
250 struct scatterlist hdr, buf, *sgs[2];
251 struct virtqueue *vq;
252 int ret;
253
254 vq = vsock->vqs[VSOCK_VQ_RX];
255
256 do {
257 pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
258 if (!pkt)
259 break;
260
261 pkt->buf = kmalloc(buf_len, GFP_KERNEL);
262 if (!pkt->buf) {
263 virtio_transport_free_pkt(pkt);
264 break;
265 }
266
267 pkt->buf_len = buf_len;
268 pkt->len = buf_len;
269
270 sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
271 sgs[0] = &hdr;
272
273 sg_init_one(&buf, pkt->buf, buf_len);
274 sgs[1] = &buf;
275 ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL);
276 if (ret) {
277 virtio_transport_free_pkt(pkt);
278 break;
279 }
280 vsock->rx_buf_nr++;
281 } while (vq->num_free);
282 if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
283 vsock->rx_buf_max_nr = vsock->rx_buf_nr;
284 virtqueue_kick(vq);
285 }
286
virtio_transport_tx_work(struct work_struct * work)287 static void virtio_transport_tx_work(struct work_struct *work)
288 {
289 struct virtio_vsock *vsock =
290 container_of(work, struct virtio_vsock, tx_work);
291 struct virtqueue *vq;
292 bool added = false;
293
294 vq = vsock->vqs[VSOCK_VQ_TX];
295 mutex_lock(&vsock->tx_lock);
296
297 if (!vsock->tx_run)
298 goto out;
299
300 do {
301 struct virtio_vsock_pkt *pkt;
302 unsigned int len;
303
304 virtqueue_disable_cb(vq);
305 while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
306 virtio_transport_free_pkt(pkt);
307 added = true;
308 }
309 } while (!virtqueue_enable_cb(vq));
310
311 out:
312 mutex_unlock(&vsock->tx_lock);
313
314 if (added)
315 queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
316 }
317
318 /* Is there space left for replies to rx packets? */
virtio_transport_more_replies(struct virtio_vsock * vsock)319 static bool virtio_transport_more_replies(struct virtio_vsock *vsock)
320 {
321 struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX];
322 int val;
323
324 smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
325 val = atomic_read(&vsock->queued_replies);
326
327 return val < virtqueue_get_vring_size(vq);
328 }
329
330 /* event_lock must be held */
virtio_vsock_event_fill_one(struct virtio_vsock * vsock,struct virtio_vsock_event * event)331 static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock,
332 struct virtio_vsock_event *event)
333 {
334 struct scatterlist sg;
335 struct virtqueue *vq;
336
337 vq = vsock->vqs[VSOCK_VQ_EVENT];
338
339 sg_init_one(&sg, event, sizeof(*event));
340
341 return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL);
342 }
343
344 /* event_lock must be held */
virtio_vsock_event_fill(struct virtio_vsock * vsock)345 static void virtio_vsock_event_fill(struct virtio_vsock *vsock)
346 {
347 size_t i;
348
349 for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) {
350 struct virtio_vsock_event *event = &vsock->event_list[i];
351
352 virtio_vsock_event_fill_one(vsock, event);
353 }
354
355 virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
356 }
357
virtio_vsock_reset_sock(struct sock * sk)358 static void virtio_vsock_reset_sock(struct sock *sk)
359 {
360 struct vsock_sock *vsk = vsock_sk(sk);
361
362 /* vmci_transport.c doesn't take sk_lock here either. At least we're
363 * under vsock_table_lock so the sock cannot disappear while we're
364 * executing.
365 */
366
367 /* Only handle our own sockets */
368 if (vsk->transport != &virtio_transport.transport)
369 return;
370
371 sk->sk_state = TCP_CLOSE;
372 sk->sk_err = ECONNRESET;
373 sk->sk_error_report(sk);
374 }
375
virtio_vsock_update_guest_cid(struct virtio_vsock * vsock)376 static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock)
377 {
378 struct virtio_device *vdev = vsock->vdev;
379 __le64 guest_cid;
380
381 vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
382 &guest_cid, sizeof(guest_cid));
383 vsock->guest_cid = le64_to_cpu(guest_cid);
384 }
385
386 /* event_lock must be held */
virtio_vsock_event_handle(struct virtio_vsock * vsock,struct virtio_vsock_event * event)387 static void virtio_vsock_event_handle(struct virtio_vsock *vsock,
388 struct virtio_vsock_event *event)
389 {
390 switch (le32_to_cpu(event->id)) {
391 case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET:
392 virtio_vsock_update_guest_cid(vsock);
393 vsock_for_each_connected_socket(virtio_vsock_reset_sock);
394 break;
395 }
396 }
397
virtio_transport_event_work(struct work_struct * work)398 static void virtio_transport_event_work(struct work_struct *work)
399 {
400 struct virtio_vsock *vsock =
401 container_of(work, struct virtio_vsock, event_work);
402 struct virtqueue *vq;
403
404 vq = vsock->vqs[VSOCK_VQ_EVENT];
405
406 mutex_lock(&vsock->event_lock);
407
408 if (!vsock->event_run)
409 goto out;
410
411 do {
412 struct virtio_vsock_event *event;
413 unsigned int len;
414
415 virtqueue_disable_cb(vq);
416 while ((event = virtqueue_get_buf(vq, &len)) != NULL) {
417 if (len == sizeof(*event))
418 virtio_vsock_event_handle(vsock, event);
419
420 virtio_vsock_event_fill_one(vsock, event);
421 }
422 } while (!virtqueue_enable_cb(vq));
423
424 virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
425 out:
426 mutex_unlock(&vsock->event_lock);
427 }
428
virtio_vsock_event_done(struct virtqueue * vq)429 static void virtio_vsock_event_done(struct virtqueue *vq)
430 {
431 struct virtio_vsock *vsock = vq->vdev->priv;
432
433 if (!vsock)
434 return;
435 queue_work(virtio_vsock_workqueue, &vsock->event_work);
436 }
437
virtio_vsock_tx_done(struct virtqueue * vq)438 static void virtio_vsock_tx_done(struct virtqueue *vq)
439 {
440 struct virtio_vsock *vsock = vq->vdev->priv;
441
442 if (!vsock)
443 return;
444 queue_work(virtio_vsock_workqueue, &vsock->tx_work);
445 }
446
virtio_vsock_rx_done(struct virtqueue * vq)447 static void virtio_vsock_rx_done(struct virtqueue *vq)
448 {
449 struct virtio_vsock *vsock = vq->vdev->priv;
450
451 if (!vsock)
452 return;
453 queue_work(virtio_vsock_workqueue, &vsock->rx_work);
454 }
455
456 static struct virtio_transport virtio_transport = {
457 .transport = {
458 .module = THIS_MODULE,
459
460 .get_local_cid = virtio_transport_get_local_cid,
461
462 .init = virtio_transport_do_socket_init,
463 .destruct = virtio_transport_destruct,
464 .release = virtio_transport_release,
465 .connect = virtio_transport_connect,
466 .shutdown = virtio_transport_shutdown,
467 .cancel_pkt = virtio_transport_cancel_pkt,
468
469 .dgram_bind = virtio_transport_dgram_bind,
470 .dgram_dequeue = virtio_transport_dgram_dequeue,
471 .dgram_enqueue = virtio_transport_dgram_enqueue,
472 .dgram_allow = virtio_transport_dgram_allow,
473
474 .stream_dequeue = virtio_transport_stream_dequeue,
475 .stream_enqueue = virtio_transport_stream_enqueue,
476 .stream_has_data = virtio_transport_stream_has_data,
477 .stream_has_space = virtio_transport_stream_has_space,
478 .stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
479 .stream_is_active = virtio_transport_stream_is_active,
480 .stream_allow = virtio_transport_stream_allow,
481
482 .notify_poll_in = virtio_transport_notify_poll_in,
483 .notify_poll_out = virtio_transport_notify_poll_out,
484 .notify_recv_init = virtio_transport_notify_recv_init,
485 .notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
486 .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
487 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
488 .notify_send_init = virtio_transport_notify_send_init,
489 .notify_send_pre_block = virtio_transport_notify_send_pre_block,
490 .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
491 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
492 .notify_buffer_size = virtio_transport_notify_buffer_size,
493 },
494
495 .send_pkt = virtio_transport_send_pkt,
496 };
497
virtio_transport_rx_work(struct work_struct * work)498 static void virtio_transport_rx_work(struct work_struct *work)
499 {
500 struct virtio_vsock *vsock =
501 container_of(work, struct virtio_vsock, rx_work);
502 struct virtqueue *vq;
503
504 vq = vsock->vqs[VSOCK_VQ_RX];
505
506 mutex_lock(&vsock->rx_lock);
507
508 if (!vsock->rx_run)
509 goto out;
510
511 do {
512 virtqueue_disable_cb(vq);
513 for (;;) {
514 struct virtio_vsock_pkt *pkt;
515 unsigned int len;
516
517 if (!virtio_transport_more_replies(vsock)) {
518 /* Stop rx until the device processes already
519 * pending replies. Leave rx virtqueue
520 * callbacks disabled.
521 */
522 goto out;
523 }
524
525 pkt = virtqueue_get_buf(vq, &len);
526 if (!pkt) {
527 break;
528 }
529
530 vsock->rx_buf_nr--;
531
532 /* Drop short/long packets */
533 if (unlikely(len < sizeof(pkt->hdr) ||
534 len > sizeof(pkt->hdr) + pkt->len)) {
535 virtio_transport_free_pkt(pkt);
536 continue;
537 }
538
539 pkt->len = len - sizeof(pkt->hdr);
540 virtio_transport_deliver_tap_pkt(pkt);
541 virtio_transport_recv_pkt(&virtio_transport, pkt);
542 }
543 } while (!virtqueue_enable_cb(vq));
544
545 out:
546 if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
547 virtio_vsock_rx_fill(vsock);
548 mutex_unlock(&vsock->rx_lock);
549 }
550
virtio_vsock_probe(struct virtio_device * vdev)551 static int virtio_vsock_probe(struct virtio_device *vdev)
552 {
553 vq_callback_t *callbacks[] = {
554 virtio_vsock_rx_done,
555 virtio_vsock_tx_done,
556 virtio_vsock_event_done,
557 };
558 static const char * const names[] = {
559 "rx",
560 "tx",
561 "event",
562 };
563 struct virtio_vsock *vsock = NULL;
564 int ret;
565
566 ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
567 if (ret)
568 return ret;
569
570 /* Only one virtio-vsock device per guest is supported */
571 if (rcu_dereference_protected(the_virtio_vsock,
572 lockdep_is_held(&the_virtio_vsock_mutex))) {
573 ret = -EBUSY;
574 goto out;
575 }
576
577 vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
578 if (!vsock) {
579 ret = -ENOMEM;
580 goto out;
581 }
582
583 vsock->vdev = vdev;
584
585 ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX,
586 vsock->vqs, callbacks, names,
587 NULL);
588 if (ret < 0)
589 goto out;
590
591 virtio_vsock_update_guest_cid(vsock);
592
593 vsock->rx_buf_nr = 0;
594 vsock->rx_buf_max_nr = 0;
595 atomic_set(&vsock->queued_replies, 0);
596
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 INIT_WORK(&vsock->rx_work, virtio_transport_rx_work);
603 INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
604 INIT_WORK(&vsock->event_work, virtio_transport_event_work);
605 INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
606
607 mutex_lock(&vsock->tx_lock);
608 vsock->tx_run = true;
609 mutex_unlock(&vsock->tx_lock);
610
611 mutex_lock(&vsock->rx_lock);
612 virtio_vsock_rx_fill(vsock);
613 vsock->rx_run = true;
614 mutex_unlock(&vsock->rx_lock);
615
616 mutex_lock(&vsock->event_lock);
617 virtio_vsock_event_fill(vsock);
618 vsock->event_run = true;
619 mutex_unlock(&vsock->event_lock);
620
621 vdev->priv = vsock;
622 rcu_assign_pointer(the_virtio_vsock, vsock);
623
624 mutex_unlock(&the_virtio_vsock_mutex);
625 return 0;
626
627 out:
628 kfree(vsock);
629 mutex_unlock(&the_virtio_vsock_mutex);
630 return ret;
631 }
632
virtio_vsock_remove(struct virtio_device * vdev)633 static void virtio_vsock_remove(struct virtio_device *vdev)
634 {
635 struct virtio_vsock *vsock = vdev->priv;
636 struct virtio_vsock_pkt *pkt;
637
638 mutex_lock(&the_virtio_vsock_mutex);
639
640 vdev->priv = NULL;
641 rcu_assign_pointer(the_virtio_vsock, NULL);
642 synchronize_rcu();
643
644 /* Reset all connected sockets when the device disappear */
645 vsock_for_each_connected_socket(virtio_vsock_reset_sock);
646
647 /* Stop all work handlers to make sure no one is accessing the device,
648 * so we can safely call vdev->config->reset().
649 */
650 mutex_lock(&vsock->rx_lock);
651 vsock->rx_run = false;
652 mutex_unlock(&vsock->rx_lock);
653
654 mutex_lock(&vsock->tx_lock);
655 vsock->tx_run = false;
656 mutex_unlock(&vsock->tx_lock);
657
658 mutex_lock(&vsock->event_lock);
659 vsock->event_run = false;
660 mutex_unlock(&vsock->event_lock);
661
662 /* Flush all device writes and interrupts, device will not use any
663 * more buffers.
664 */
665 vdev->config->reset(vdev);
666
667 mutex_lock(&vsock->rx_lock);
668 while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX])))
669 virtio_transport_free_pkt(pkt);
670 mutex_unlock(&vsock->rx_lock);
671
672 mutex_lock(&vsock->tx_lock);
673 while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
674 virtio_transport_free_pkt(pkt);
675 mutex_unlock(&vsock->tx_lock);
676
677 spin_lock_bh(&vsock->send_pkt_list_lock);
678 while (!list_empty(&vsock->send_pkt_list)) {
679 pkt = list_first_entry(&vsock->send_pkt_list,
680 struct virtio_vsock_pkt, list);
681 list_del(&pkt->list);
682 virtio_transport_free_pkt(pkt);
683 }
684 spin_unlock_bh(&vsock->send_pkt_list_lock);
685
686 /* Delete virtqueues and flush outstanding callbacks if any */
687 vdev->config->del_vqs(vdev);
688
689 /* Other works can be queued before 'config->del_vqs()', so we flush
690 * all works before to free the vsock object to avoid use after free.
691 */
692 flush_work(&vsock->rx_work);
693 flush_work(&vsock->tx_work);
694 flush_work(&vsock->event_work);
695 flush_work(&vsock->send_pkt_work);
696
697 mutex_unlock(&the_virtio_vsock_mutex);
698
699 kfree(vsock);
700 }
701
702 static struct virtio_device_id id_table[] = {
703 { VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
704 { 0 },
705 };
706
707 static unsigned int features[] = {
708 };
709
710 static struct virtio_driver virtio_vsock_driver = {
711 .feature_table = features,
712 .feature_table_size = ARRAY_SIZE(features),
713 .driver.name = KBUILD_MODNAME,
714 .driver.owner = THIS_MODULE,
715 .id_table = id_table,
716 .probe = virtio_vsock_probe,
717 .remove = virtio_vsock_remove,
718 };
719
virtio_vsock_init(void)720 static int __init virtio_vsock_init(void)
721 {
722 int ret;
723
724 virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0);
725 if (!virtio_vsock_workqueue)
726 return -ENOMEM;
727
728 ret = vsock_core_register(&virtio_transport.transport,
729 VSOCK_TRANSPORT_F_G2H);
730 if (ret)
731 goto out_wq;
732
733 ret = register_virtio_driver(&virtio_vsock_driver);
734 if (ret)
735 goto out_vci;
736
737 return 0;
738
739 out_vci:
740 vsock_core_unregister(&virtio_transport.transport);
741 out_wq:
742 destroy_workqueue(virtio_vsock_workqueue);
743 return ret;
744 }
745
virtio_vsock_exit(void)746 static void __exit virtio_vsock_exit(void)
747 {
748 unregister_virtio_driver(&virtio_vsock_driver);
749 vsock_core_unregister(&virtio_transport.transport);
750 destroy_workqueue(virtio_vsock_workqueue);
751 }
752
753 module_init(virtio_vsock_init);
754 module_exit(virtio_vsock_exit);
755 MODULE_LICENSE("GPL v2");
756 MODULE_AUTHOR("Asias He");
757 MODULE_DESCRIPTION("virtio transport for vsock");
758 MODULE_DEVICE_TABLE(virtio, id_table);
759