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
24static struct workqueue_struct *virtio_vsock_workqueue;
25static struct virtio_vsock __rcu *the_virtio_vsock;
26static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */
27static struct virtio_transport virtio_transport; /* forward declaration */
28
29struct 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
68static 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;
81out_rcu:
82	rcu_read_unlock();
83	return ret;
84}
85
86static void
87virtio_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
158out:
159	mutex_unlock(&vsock->tx_lock);
160
161	if (restart_rx)
162		queue_work(virtio_vsock_workqueue, &vsock->rx_work);
163}
164
165static int
166virtio_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
194out_rcu:
195	rcu_read_unlock();
196	return len;
197}
198
199static int
200virtio_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
241out_rcu:
242	rcu_read_unlock();
243	return ret;
244}
245
246static 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
287static 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
311out:
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? */
319static 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 */
331static 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 */
345static 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
358static void virtio_vsock_reset_sock(struct sock *sk)
359{
360	/* vmci_transport.c doesn't take sk_lock here either.  At least we're
361	 * under vsock_table_lock so the sock cannot disappear while we're
362	 * executing.
363	 */
364
365	sk->sk_state = TCP_CLOSE;
366	sk->sk_err = ECONNRESET;
367	sk->sk_error_report(sk);
368}
369
370static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock)
371{
372	struct virtio_device *vdev = vsock->vdev;
373	__le64 guest_cid;
374
375	vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
376			  &guest_cid, sizeof(guest_cid));
377	vsock->guest_cid = le64_to_cpu(guest_cid);
378}
379
380/* event_lock must be held */
381static void virtio_vsock_event_handle(struct virtio_vsock *vsock,
382				      struct virtio_vsock_event *event)
383{
384	switch (le32_to_cpu(event->id)) {
385	case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET:
386		virtio_vsock_update_guest_cid(vsock);
387		vsock_for_each_connected_socket(&virtio_transport.transport,
388						virtio_vsock_reset_sock);
389		break;
390	}
391}
392
393static void virtio_transport_event_work(struct work_struct *work)
394{
395	struct virtio_vsock *vsock =
396		container_of(work, struct virtio_vsock, event_work);
397	struct virtqueue *vq;
398
399	vq = vsock->vqs[VSOCK_VQ_EVENT];
400
401	mutex_lock(&vsock->event_lock);
402
403	if (!vsock->event_run)
404		goto out;
405
406	do {
407		struct virtio_vsock_event *event;
408		unsigned int len;
409
410		virtqueue_disable_cb(vq);
411		while ((event = virtqueue_get_buf(vq, &len)) != NULL) {
412			if (len == sizeof(*event))
413				virtio_vsock_event_handle(vsock, event);
414
415			virtio_vsock_event_fill_one(vsock, event);
416		}
417	} while (!virtqueue_enable_cb(vq));
418
419	virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
420out:
421	mutex_unlock(&vsock->event_lock);
422}
423
424static void virtio_vsock_event_done(struct virtqueue *vq)
425{
426	struct virtio_vsock *vsock = vq->vdev->priv;
427
428	if (!vsock)
429		return;
430	queue_work(virtio_vsock_workqueue, &vsock->event_work);
431}
432
433static void virtio_vsock_tx_done(struct virtqueue *vq)
434{
435	struct virtio_vsock *vsock = vq->vdev->priv;
436
437	if (!vsock)
438		return;
439	queue_work(virtio_vsock_workqueue, &vsock->tx_work);
440}
441
442static void virtio_vsock_rx_done(struct virtqueue *vq)
443{
444	struct virtio_vsock *vsock = vq->vdev->priv;
445
446	if (!vsock)
447		return;
448	queue_work(virtio_vsock_workqueue, &vsock->rx_work);
449}
450
451static struct virtio_transport virtio_transport = {
452	.transport = {
453		.module                   = THIS_MODULE,
454
455		.get_local_cid            = virtio_transport_get_local_cid,
456
457		.init                     = virtio_transport_do_socket_init,
458		.destruct                 = virtio_transport_destruct,
459		.release                  = virtio_transport_release,
460		.connect                  = virtio_transport_connect,
461		.shutdown                 = virtio_transport_shutdown,
462		.cancel_pkt               = virtio_transport_cancel_pkt,
463
464		.dgram_bind               = virtio_transport_dgram_bind,
465		.dgram_dequeue            = virtio_transport_dgram_dequeue,
466		.dgram_enqueue            = virtio_transport_dgram_enqueue,
467		.dgram_allow              = virtio_transport_dgram_allow,
468
469		.stream_dequeue           = virtio_transport_stream_dequeue,
470		.stream_enqueue           = virtio_transport_stream_enqueue,
471		.stream_has_data          = virtio_transport_stream_has_data,
472		.stream_has_space         = virtio_transport_stream_has_space,
473		.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
474		.stream_is_active         = virtio_transport_stream_is_active,
475		.stream_allow             = virtio_transport_stream_allow,
476
477		.notify_poll_in           = virtio_transport_notify_poll_in,
478		.notify_poll_out          = virtio_transport_notify_poll_out,
479		.notify_recv_init         = virtio_transport_notify_recv_init,
480		.notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
481		.notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
482		.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
483		.notify_send_init         = virtio_transport_notify_send_init,
484		.notify_send_pre_block    = virtio_transport_notify_send_pre_block,
485		.notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
486		.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
487		.notify_buffer_size       = virtio_transport_notify_buffer_size,
488	},
489
490	.send_pkt = virtio_transport_send_pkt,
491};
492
493static void virtio_transport_rx_work(struct work_struct *work)
494{
495	struct virtio_vsock *vsock =
496		container_of(work, struct virtio_vsock, rx_work);
497	struct virtqueue *vq;
498
499	vq = vsock->vqs[VSOCK_VQ_RX];
500
501	mutex_lock(&vsock->rx_lock);
502
503	if (!vsock->rx_run)
504		goto out;
505
506	do {
507		virtqueue_disable_cb(vq);
508		for (;;) {
509			struct virtio_vsock_pkt *pkt;
510			unsigned int len;
511
512			if (!virtio_transport_more_replies(vsock)) {
513				/* Stop rx until the device processes already
514				 * pending replies.  Leave rx virtqueue
515				 * callbacks disabled.
516				 */
517				goto out;
518			}
519
520			pkt = virtqueue_get_buf(vq, &len);
521			if (!pkt) {
522				break;
523			}
524
525			vsock->rx_buf_nr--;
526
527			/* Drop short/long packets */
528			if (unlikely(len < sizeof(pkt->hdr) ||
529				     len > sizeof(pkt->hdr) + pkt->len)) {
530				virtio_transport_free_pkt(pkt);
531				continue;
532			}
533
534			pkt->len = len - sizeof(pkt->hdr);
535			virtio_transport_deliver_tap_pkt(pkt);
536			virtio_transport_recv_pkt(&virtio_transport, pkt);
537		}
538	} while (!virtqueue_enable_cb(vq));
539
540out:
541	if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
542		virtio_vsock_rx_fill(vsock);
543	mutex_unlock(&vsock->rx_lock);
544}
545
546static int virtio_vsock_probe(struct virtio_device *vdev)
547{
548	vq_callback_t *callbacks[] = {
549		virtio_vsock_rx_done,
550		virtio_vsock_tx_done,
551		virtio_vsock_event_done,
552	};
553	static const char * const names[] = {
554		"rx",
555		"tx",
556		"event",
557	};
558	struct virtio_vsock *vsock = NULL;
559	int ret;
560
561	ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
562	if (ret)
563		return ret;
564
565	/* Only one virtio-vsock device per guest is supported */
566	if (rcu_dereference_protected(the_virtio_vsock,
567				lockdep_is_held(&the_virtio_vsock_mutex))) {
568		ret = -EBUSY;
569		goto out;
570	}
571
572	vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
573	if (!vsock) {
574		ret = -ENOMEM;
575		goto out;
576	}
577
578	vsock->vdev = vdev;
579
580	ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX,
581			      vsock->vqs, callbacks, names,
582			      NULL);
583	if (ret < 0)
584		goto out;
585
586	virtio_vsock_update_guest_cid(vsock);
587
588	vsock->rx_buf_nr = 0;
589	vsock->rx_buf_max_nr = 0;
590	atomic_set(&vsock->queued_replies, 0);
591
592	mutex_init(&vsock->tx_lock);
593	mutex_init(&vsock->rx_lock);
594	mutex_init(&vsock->event_lock);
595	spin_lock_init(&vsock->send_pkt_list_lock);
596	INIT_LIST_HEAD(&vsock->send_pkt_list);
597	INIT_WORK(&vsock->rx_work, virtio_transport_rx_work);
598	INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
599	INIT_WORK(&vsock->event_work, virtio_transport_event_work);
600	INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
601
602	mutex_lock(&vsock->tx_lock);
603	vsock->tx_run = true;
604	mutex_unlock(&vsock->tx_lock);
605
606	mutex_lock(&vsock->rx_lock);
607	virtio_vsock_rx_fill(vsock);
608	vsock->rx_run = true;
609	mutex_unlock(&vsock->rx_lock);
610
611	mutex_lock(&vsock->event_lock);
612	virtio_vsock_event_fill(vsock);
613	vsock->event_run = true;
614	mutex_unlock(&vsock->event_lock);
615
616	vdev->priv = vsock;
617	rcu_assign_pointer(the_virtio_vsock, vsock);
618
619	mutex_unlock(&the_virtio_vsock_mutex);
620	return 0;
621
622out:
623	kfree(vsock);
624	mutex_unlock(&the_virtio_vsock_mutex);
625	return ret;
626}
627
628static void virtio_vsock_remove(struct virtio_device *vdev)
629{
630	struct virtio_vsock *vsock = vdev->priv;
631	struct virtio_vsock_pkt *pkt;
632
633	mutex_lock(&the_virtio_vsock_mutex);
634
635	vdev->priv = NULL;
636	rcu_assign_pointer(the_virtio_vsock, NULL);
637	synchronize_rcu();
638
639	/* Reset all connected sockets when the device disappear */
640	vsock_for_each_connected_socket(&virtio_transport.transport,
641					virtio_vsock_reset_sock);
642
643	/* Stop all work handlers to make sure no one is accessing the device,
644	 * so we can safely call vdev->config->reset().
645	 */
646	mutex_lock(&vsock->rx_lock);
647	vsock->rx_run = false;
648	mutex_unlock(&vsock->rx_lock);
649
650	mutex_lock(&vsock->tx_lock);
651	vsock->tx_run = false;
652	mutex_unlock(&vsock->tx_lock);
653
654	mutex_lock(&vsock->event_lock);
655	vsock->event_run = false;
656	mutex_unlock(&vsock->event_lock);
657
658	/* Flush all device writes and interrupts, device will not use any
659	 * more buffers.
660	 */
661	vdev->config->reset(vdev);
662
663	mutex_lock(&vsock->rx_lock);
664	while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX])))
665		virtio_transport_free_pkt(pkt);
666	mutex_unlock(&vsock->rx_lock);
667
668	mutex_lock(&vsock->tx_lock);
669	while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
670		virtio_transport_free_pkt(pkt);
671	mutex_unlock(&vsock->tx_lock);
672
673	spin_lock_bh(&vsock->send_pkt_list_lock);
674	while (!list_empty(&vsock->send_pkt_list)) {
675		pkt = list_first_entry(&vsock->send_pkt_list,
676				       struct virtio_vsock_pkt, list);
677		list_del(&pkt->list);
678		virtio_transport_free_pkt(pkt);
679	}
680	spin_unlock_bh(&vsock->send_pkt_list_lock);
681
682	/* Delete virtqueues and flush outstanding callbacks if any */
683	vdev->config->del_vqs(vdev);
684
685	/* Other works can be queued before 'config->del_vqs()', so we flush
686	 * all works before to free the vsock object to avoid use after free.
687	 */
688	flush_work(&vsock->rx_work);
689	flush_work(&vsock->tx_work);
690	flush_work(&vsock->event_work);
691	flush_work(&vsock->send_pkt_work);
692
693	mutex_unlock(&the_virtio_vsock_mutex);
694
695	kfree(vsock);
696}
697
698static struct virtio_device_id id_table[] = {
699	{ VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
700	{ 0 },
701};
702
703static unsigned int features[] = {
704};
705
706static struct virtio_driver virtio_vsock_driver = {
707	.feature_table = features,
708	.feature_table_size = ARRAY_SIZE(features),
709	.driver.name = KBUILD_MODNAME,
710	.driver.owner = THIS_MODULE,
711	.id_table = id_table,
712	.probe = virtio_vsock_probe,
713	.remove = virtio_vsock_remove,
714};
715
716static int __init virtio_vsock_init(void)
717{
718	int ret;
719
720	virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0);
721	if (!virtio_vsock_workqueue)
722		return -ENOMEM;
723
724	ret = vsock_core_register(&virtio_transport.transport,
725				  VSOCK_TRANSPORT_F_G2H);
726	if (ret)
727		goto out_wq;
728
729	ret = register_virtio_driver(&virtio_vsock_driver);
730	if (ret)
731		goto out_vci;
732
733	return 0;
734
735out_vci:
736	vsock_core_unregister(&virtio_transport.transport);
737out_wq:
738	destroy_workqueue(virtio_vsock_workqueue);
739	return ret;
740}
741
742static void __exit virtio_vsock_exit(void)
743{
744	unregister_virtio_driver(&virtio_vsock_driver);
745	vsock_core_unregister(&virtio_transport.transport);
746	destroy_workqueue(virtio_vsock_workqueue);
747}
748
749module_init(virtio_vsock_init);
750module_exit(virtio_vsock_exit);
751MODULE_LICENSE("GPL v2");
752MODULE_AUTHOR("Asias He");
753MODULE_DESCRIPTION("virtio transport for vsock");
754MODULE_DEVICE_TABLE(virtio, id_table);
755