xref: /openbmc/linux/drivers/vhost/vsock.c (revision b226acab)
1 /*
2  * vhost 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  * This work is licensed under the terms of the GNU GPL, version 2.
9  */
10 #include <linux/miscdevice.h>
11 #include <linux/atomic.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/vmalloc.h>
15 #include <net/sock.h>
16 #include <linux/virtio_vsock.h>
17 #include <linux/vhost.h>
18 
19 #include <net/af_vsock.h>
20 #include "vhost.h"
21 
22 #define VHOST_VSOCK_DEFAULT_HOST_CID	2
23 
24 enum {
25 	VHOST_VSOCK_FEATURES = VHOST_FEATURES,
26 };
27 
28 /* Used to track all the vhost_vsock instances on the system. */
29 static DEFINE_SPINLOCK(vhost_vsock_lock);
30 static LIST_HEAD(vhost_vsock_list);
31 
32 struct vhost_vsock {
33 	struct vhost_dev dev;
34 	struct vhost_virtqueue vqs[2];
35 
36 	/* Link to global vhost_vsock_list, protected by vhost_vsock_lock */
37 	struct list_head list;
38 
39 	struct vhost_work send_pkt_work;
40 	spinlock_t send_pkt_list_lock;
41 	struct list_head send_pkt_list;	/* host->guest pending packets */
42 
43 	atomic_t queued_replies;
44 
45 	u32 guest_cid;
46 };
47 
48 static u32 vhost_transport_get_local_cid(void)
49 {
50 	return VHOST_VSOCK_DEFAULT_HOST_CID;
51 }
52 
53 static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
54 {
55 	struct vhost_vsock *vsock;
56 
57 	spin_lock_bh(&vhost_vsock_lock);
58 	list_for_each_entry(vsock, &vhost_vsock_list, list) {
59 		u32 other_cid = vsock->guest_cid;
60 
61 		/* Skip instances that have no CID yet */
62 		if (other_cid == 0)
63 			continue;
64 
65 		if (other_cid == guest_cid) {
66 			spin_unlock_bh(&vhost_vsock_lock);
67 			return vsock;
68 		}
69 	}
70 	spin_unlock_bh(&vhost_vsock_lock);
71 
72 	return NULL;
73 }
74 
75 static void
76 vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
77 			    struct vhost_virtqueue *vq)
78 {
79 	struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
80 	bool added = false;
81 	bool restart_tx = false;
82 
83 	mutex_lock(&vq->mutex);
84 
85 	if (!vq->private_data)
86 		goto out;
87 
88 	/* Avoid further vmexits, we're already processing the virtqueue */
89 	vhost_disable_notify(&vsock->dev, vq);
90 
91 	for (;;) {
92 		struct virtio_vsock_pkt *pkt;
93 		struct iov_iter iov_iter;
94 		unsigned out, in;
95 		size_t nbytes;
96 		size_t len;
97 		int head;
98 
99 		spin_lock_bh(&vsock->send_pkt_list_lock);
100 		if (list_empty(&vsock->send_pkt_list)) {
101 			spin_unlock_bh(&vsock->send_pkt_list_lock);
102 			vhost_enable_notify(&vsock->dev, vq);
103 			break;
104 		}
105 
106 		pkt = list_first_entry(&vsock->send_pkt_list,
107 				       struct virtio_vsock_pkt, list);
108 		list_del_init(&pkt->list);
109 		spin_unlock_bh(&vsock->send_pkt_list_lock);
110 
111 		head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
112 					 &out, &in, NULL, NULL);
113 		if (head < 0) {
114 			spin_lock_bh(&vsock->send_pkt_list_lock);
115 			list_add(&pkt->list, &vsock->send_pkt_list);
116 			spin_unlock_bh(&vsock->send_pkt_list_lock);
117 			break;
118 		}
119 
120 		if (head == vq->num) {
121 			spin_lock_bh(&vsock->send_pkt_list_lock);
122 			list_add(&pkt->list, &vsock->send_pkt_list);
123 			spin_unlock_bh(&vsock->send_pkt_list_lock);
124 
125 			/* We cannot finish yet if more buffers snuck in while
126 			 * re-enabling notify.
127 			 */
128 			if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
129 				vhost_disable_notify(&vsock->dev, vq);
130 				continue;
131 			}
132 			break;
133 		}
134 
135 		if (out) {
136 			virtio_transport_free_pkt(pkt);
137 			vq_err(vq, "Expected 0 output buffers, got %u\n", out);
138 			break;
139 		}
140 
141 		len = iov_length(&vq->iov[out], in);
142 		iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len);
143 
144 		nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
145 		if (nbytes != sizeof(pkt->hdr)) {
146 			virtio_transport_free_pkt(pkt);
147 			vq_err(vq, "Faulted on copying pkt hdr\n");
148 			break;
149 		}
150 
151 		nbytes = copy_to_iter(pkt->buf, pkt->len, &iov_iter);
152 		if (nbytes != pkt->len) {
153 			virtio_transport_free_pkt(pkt);
154 			vq_err(vq, "Faulted on copying pkt buf\n");
155 			break;
156 		}
157 
158 		vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
159 		added = true;
160 
161 		if (pkt->reply) {
162 			int val;
163 
164 			val = atomic_dec_return(&vsock->queued_replies);
165 
166 			/* Do we have resources to resume tx processing? */
167 			if (val + 1 == tx_vq->num)
168 				restart_tx = true;
169 		}
170 
171 		virtio_transport_free_pkt(pkt);
172 	}
173 	if (added)
174 		vhost_signal(&vsock->dev, vq);
175 
176 out:
177 	mutex_unlock(&vq->mutex);
178 
179 	if (restart_tx)
180 		vhost_poll_queue(&tx_vq->poll);
181 }
182 
183 static void vhost_transport_send_pkt_work(struct vhost_work *work)
184 {
185 	struct vhost_virtqueue *vq;
186 	struct vhost_vsock *vsock;
187 
188 	vsock = container_of(work, struct vhost_vsock, send_pkt_work);
189 	vq = &vsock->vqs[VSOCK_VQ_RX];
190 
191 	vhost_transport_do_send_pkt(vsock, vq);
192 }
193 
194 static int
195 vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt)
196 {
197 	struct vhost_vsock *vsock;
198 	struct vhost_virtqueue *vq;
199 	int len = pkt->len;
200 
201 	/* Find the vhost_vsock according to guest context id  */
202 	vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid));
203 	if (!vsock) {
204 		virtio_transport_free_pkt(pkt);
205 		return -ENODEV;
206 	}
207 
208 	vq = &vsock->vqs[VSOCK_VQ_RX];
209 
210 	if (pkt->reply)
211 		atomic_inc(&vsock->queued_replies);
212 
213 	spin_lock_bh(&vsock->send_pkt_list_lock);
214 	list_add_tail(&pkt->list, &vsock->send_pkt_list);
215 	spin_unlock_bh(&vsock->send_pkt_list_lock);
216 
217 	vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
218 	return len;
219 }
220 
221 static struct virtio_vsock_pkt *
222 vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
223 		      unsigned int out, unsigned int in)
224 {
225 	struct virtio_vsock_pkt *pkt;
226 	struct iov_iter iov_iter;
227 	size_t nbytes;
228 	size_t len;
229 
230 	if (in != 0) {
231 		vq_err(vq, "Expected 0 input buffers, got %u\n", in);
232 		return NULL;
233 	}
234 
235 	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
236 	if (!pkt)
237 		return NULL;
238 
239 	len = iov_length(vq->iov, out);
240 	iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);
241 
242 	nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
243 	if (nbytes != sizeof(pkt->hdr)) {
244 		vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
245 		       sizeof(pkt->hdr), nbytes);
246 		kfree(pkt);
247 		return NULL;
248 	}
249 
250 	if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM)
251 		pkt->len = le32_to_cpu(pkt->hdr.len);
252 
253 	/* No payload */
254 	if (!pkt->len)
255 		return pkt;
256 
257 	/* The pkt is too big */
258 	if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
259 		kfree(pkt);
260 		return NULL;
261 	}
262 
263 	pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
264 	if (!pkt->buf) {
265 		kfree(pkt);
266 		return NULL;
267 	}
268 
269 	nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
270 	if (nbytes != pkt->len) {
271 		vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
272 		       pkt->len, nbytes);
273 		virtio_transport_free_pkt(pkt);
274 		return NULL;
275 	}
276 
277 	return pkt;
278 }
279 
280 /* Is there space left for replies to rx packets? */
281 static bool vhost_vsock_more_replies(struct vhost_vsock *vsock)
282 {
283 	struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX];
284 	int val;
285 
286 	smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
287 	val = atomic_read(&vsock->queued_replies);
288 
289 	return val < vq->num;
290 }
291 
292 static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
293 {
294 	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
295 						  poll.work);
296 	struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
297 						 dev);
298 	struct virtio_vsock_pkt *pkt;
299 	int head;
300 	unsigned int out, in;
301 	bool added = false;
302 
303 	mutex_lock(&vq->mutex);
304 
305 	if (!vq->private_data)
306 		goto out;
307 
308 	vhost_disable_notify(&vsock->dev, vq);
309 	for (;;) {
310 		if (!vhost_vsock_more_replies(vsock)) {
311 			/* Stop tx until the device processes already
312 			 * pending replies.  Leave tx virtqueue
313 			 * callbacks disabled.
314 			 */
315 			goto no_more_replies;
316 		}
317 
318 		head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
319 					 &out, &in, NULL, NULL);
320 		if (head < 0)
321 			break;
322 
323 		if (head == vq->num) {
324 			if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
325 				vhost_disable_notify(&vsock->dev, vq);
326 				continue;
327 			}
328 			break;
329 		}
330 
331 		pkt = vhost_vsock_alloc_pkt(vq, out, in);
332 		if (!pkt) {
333 			vq_err(vq, "Faulted on pkt\n");
334 			continue;
335 		}
336 
337 		/* Only accept correctly addressed packets */
338 		if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
339 			virtio_transport_recv_pkt(pkt);
340 		else
341 			virtio_transport_free_pkt(pkt);
342 
343 		vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
344 		added = true;
345 	}
346 
347 no_more_replies:
348 	if (added)
349 		vhost_signal(&vsock->dev, vq);
350 
351 out:
352 	mutex_unlock(&vq->mutex);
353 }
354 
355 static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
356 {
357 	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
358 						poll.work);
359 	struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
360 						 dev);
361 
362 	vhost_transport_do_send_pkt(vsock, vq);
363 }
364 
365 static int vhost_vsock_start(struct vhost_vsock *vsock)
366 {
367 	size_t i;
368 	int ret;
369 
370 	mutex_lock(&vsock->dev.mutex);
371 
372 	ret = vhost_dev_check_owner(&vsock->dev);
373 	if (ret)
374 		goto err;
375 
376 	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
377 		struct vhost_virtqueue *vq = &vsock->vqs[i];
378 
379 		mutex_lock(&vq->mutex);
380 
381 		if (!vhost_vq_access_ok(vq)) {
382 			ret = -EFAULT;
383 			mutex_unlock(&vq->mutex);
384 			goto err_vq;
385 		}
386 
387 		if (!vq->private_data) {
388 			vq->private_data = vsock;
389 			vhost_vq_init_access(vq);
390 		}
391 
392 		mutex_unlock(&vq->mutex);
393 	}
394 
395 	mutex_unlock(&vsock->dev.mutex);
396 	return 0;
397 
398 err_vq:
399 	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
400 		struct vhost_virtqueue *vq = &vsock->vqs[i];
401 
402 		mutex_lock(&vq->mutex);
403 		vq->private_data = NULL;
404 		mutex_unlock(&vq->mutex);
405 	}
406 err:
407 	mutex_unlock(&vsock->dev.mutex);
408 	return ret;
409 }
410 
411 static int vhost_vsock_stop(struct vhost_vsock *vsock)
412 {
413 	size_t i;
414 	int ret;
415 
416 	mutex_lock(&vsock->dev.mutex);
417 
418 	ret = vhost_dev_check_owner(&vsock->dev);
419 	if (ret)
420 		goto err;
421 
422 	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
423 		struct vhost_virtqueue *vq = &vsock->vqs[i];
424 
425 		mutex_lock(&vq->mutex);
426 		vq->private_data = NULL;
427 		mutex_unlock(&vq->mutex);
428 	}
429 
430 err:
431 	mutex_unlock(&vsock->dev.mutex);
432 	return ret;
433 }
434 
435 static void vhost_vsock_free(struct vhost_vsock *vsock)
436 {
437 	kvfree(vsock);
438 }
439 
440 static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
441 {
442 	struct vhost_virtqueue **vqs;
443 	struct vhost_vsock *vsock;
444 	int ret;
445 
446 	/* This struct is large and allocation could fail, fall back to vmalloc
447 	 * if there is no other way.
448 	 */
449 	vsock = kzalloc(sizeof(*vsock), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
450 	if (!vsock) {
451 		vsock = vmalloc(sizeof(*vsock));
452 		if (!vsock)
453 			return -ENOMEM;
454 	}
455 
456 	vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
457 	if (!vqs) {
458 		ret = -ENOMEM;
459 		goto out;
460 	}
461 
462 	atomic_set(&vsock->queued_replies, 0);
463 
464 	vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
465 	vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
466 	vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
467 	vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
468 
469 	vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs));
470 
471 	file->private_data = vsock;
472 	spin_lock_init(&vsock->send_pkt_list_lock);
473 	INIT_LIST_HEAD(&vsock->send_pkt_list);
474 	vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
475 
476 	spin_lock_bh(&vhost_vsock_lock);
477 	list_add_tail(&vsock->list, &vhost_vsock_list);
478 	spin_unlock_bh(&vhost_vsock_lock);
479 	return 0;
480 
481 out:
482 	vhost_vsock_free(vsock);
483 	return ret;
484 }
485 
486 static void vhost_vsock_flush(struct vhost_vsock *vsock)
487 {
488 	int i;
489 
490 	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++)
491 		if (vsock->vqs[i].handle_kick)
492 			vhost_poll_flush(&vsock->vqs[i].poll);
493 	vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
494 }
495 
496 static void vhost_vsock_reset_orphans(struct sock *sk)
497 {
498 	struct vsock_sock *vsk = vsock_sk(sk);
499 
500 	/* vmci_transport.c doesn't take sk_lock here either.  At least we're
501 	 * under vsock_table_lock so the sock cannot disappear while we're
502 	 * executing.
503 	 */
504 
505 	if (!vhost_vsock_get(vsk->local_addr.svm_cid)) {
506 		sock_set_flag(sk, SOCK_DONE);
507 		vsk->peer_shutdown = SHUTDOWN_MASK;
508 		sk->sk_state = SS_UNCONNECTED;
509 		sk->sk_err = ECONNRESET;
510 		sk->sk_error_report(sk);
511 	}
512 }
513 
514 static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
515 {
516 	struct vhost_vsock *vsock = file->private_data;
517 
518 	spin_lock_bh(&vhost_vsock_lock);
519 	list_del(&vsock->list);
520 	spin_unlock_bh(&vhost_vsock_lock);
521 
522 	/* Iterating over all connections for all CIDs to find orphans is
523 	 * inefficient.  Room for improvement here. */
524 	vsock_for_each_connected_socket(vhost_vsock_reset_orphans);
525 
526 	vhost_vsock_stop(vsock);
527 	vhost_vsock_flush(vsock);
528 	vhost_dev_stop(&vsock->dev);
529 
530 	spin_lock_bh(&vsock->send_pkt_list_lock);
531 	while (!list_empty(&vsock->send_pkt_list)) {
532 		struct virtio_vsock_pkt *pkt;
533 
534 		pkt = list_first_entry(&vsock->send_pkt_list,
535 				struct virtio_vsock_pkt, list);
536 		list_del_init(&pkt->list);
537 		virtio_transport_free_pkt(pkt);
538 	}
539 	spin_unlock_bh(&vsock->send_pkt_list_lock);
540 
541 	vhost_dev_cleanup(&vsock->dev, false);
542 	kfree(vsock->dev.vqs);
543 	vhost_vsock_free(vsock);
544 	return 0;
545 }
546 
547 static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
548 {
549 	struct vhost_vsock *other;
550 
551 	/* Refuse reserved CIDs */
552 	if (guest_cid <= VMADDR_CID_HOST ||
553 	    guest_cid == U32_MAX)
554 		return -EINVAL;
555 
556 	/* 64-bit CIDs are not yet supported */
557 	if (guest_cid > U32_MAX)
558 		return -EINVAL;
559 
560 	/* Refuse if CID is already in use */
561 	other = vhost_vsock_get(guest_cid);
562 	if (other && other != vsock)
563 		return -EADDRINUSE;
564 
565 	spin_lock_bh(&vhost_vsock_lock);
566 	vsock->guest_cid = guest_cid;
567 	spin_unlock_bh(&vhost_vsock_lock);
568 
569 	return 0;
570 }
571 
572 static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
573 {
574 	struct vhost_virtqueue *vq;
575 	int i;
576 
577 	if (features & ~VHOST_VSOCK_FEATURES)
578 		return -EOPNOTSUPP;
579 
580 	mutex_lock(&vsock->dev.mutex);
581 	if ((features & (1 << VHOST_F_LOG_ALL)) &&
582 	    !vhost_log_access_ok(&vsock->dev)) {
583 		mutex_unlock(&vsock->dev.mutex);
584 		return -EFAULT;
585 	}
586 
587 	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
588 		vq = &vsock->vqs[i];
589 		mutex_lock(&vq->mutex);
590 		vq->acked_features = features;
591 		mutex_unlock(&vq->mutex);
592 	}
593 	mutex_unlock(&vsock->dev.mutex);
594 	return 0;
595 }
596 
597 static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
598 				  unsigned long arg)
599 {
600 	struct vhost_vsock *vsock = f->private_data;
601 	void __user *argp = (void __user *)arg;
602 	u64 guest_cid;
603 	u64 features;
604 	int start;
605 	int r;
606 
607 	switch (ioctl) {
608 	case VHOST_VSOCK_SET_GUEST_CID:
609 		if (copy_from_user(&guest_cid, argp, sizeof(guest_cid)))
610 			return -EFAULT;
611 		return vhost_vsock_set_cid(vsock, guest_cid);
612 	case VHOST_VSOCK_SET_RUNNING:
613 		if (copy_from_user(&start, argp, sizeof(start)))
614 			return -EFAULT;
615 		if (start)
616 			return vhost_vsock_start(vsock);
617 		else
618 			return vhost_vsock_stop(vsock);
619 	case VHOST_GET_FEATURES:
620 		features = VHOST_VSOCK_FEATURES;
621 		if (copy_to_user(argp, &features, sizeof(features)))
622 			return -EFAULT;
623 		return 0;
624 	case VHOST_SET_FEATURES:
625 		if (copy_from_user(&features, argp, sizeof(features)))
626 			return -EFAULT;
627 		return vhost_vsock_set_features(vsock, features);
628 	default:
629 		mutex_lock(&vsock->dev.mutex);
630 		r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
631 		if (r == -ENOIOCTLCMD)
632 			r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
633 		else
634 			vhost_vsock_flush(vsock);
635 		mutex_unlock(&vsock->dev.mutex);
636 		return r;
637 	}
638 }
639 
640 static const struct file_operations vhost_vsock_fops = {
641 	.owner          = THIS_MODULE,
642 	.open           = vhost_vsock_dev_open,
643 	.release        = vhost_vsock_dev_release,
644 	.llseek		= noop_llseek,
645 	.unlocked_ioctl = vhost_vsock_dev_ioctl,
646 };
647 
648 static struct miscdevice vhost_vsock_misc = {
649 	.minor = MISC_DYNAMIC_MINOR,
650 	.name = "vhost-vsock",
651 	.fops = &vhost_vsock_fops,
652 };
653 
654 static struct virtio_transport vhost_transport = {
655 	.transport = {
656 		.get_local_cid            = vhost_transport_get_local_cid,
657 
658 		.init                     = virtio_transport_do_socket_init,
659 		.destruct                 = virtio_transport_destruct,
660 		.release                  = virtio_transport_release,
661 		.connect                  = virtio_transport_connect,
662 		.shutdown                 = virtio_transport_shutdown,
663 
664 		.dgram_enqueue            = virtio_transport_dgram_enqueue,
665 		.dgram_dequeue            = virtio_transport_dgram_dequeue,
666 		.dgram_bind               = virtio_transport_dgram_bind,
667 		.dgram_allow              = virtio_transport_dgram_allow,
668 
669 		.stream_enqueue           = virtio_transport_stream_enqueue,
670 		.stream_dequeue           = virtio_transport_stream_dequeue,
671 		.stream_has_data          = virtio_transport_stream_has_data,
672 		.stream_has_space         = virtio_transport_stream_has_space,
673 		.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
674 		.stream_is_active         = virtio_transport_stream_is_active,
675 		.stream_allow             = virtio_transport_stream_allow,
676 
677 		.notify_poll_in           = virtio_transport_notify_poll_in,
678 		.notify_poll_out          = virtio_transport_notify_poll_out,
679 		.notify_recv_init         = virtio_transport_notify_recv_init,
680 		.notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
681 		.notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
682 		.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
683 		.notify_send_init         = virtio_transport_notify_send_init,
684 		.notify_send_pre_block    = virtio_transport_notify_send_pre_block,
685 		.notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
686 		.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
687 
688 		.set_buffer_size          = virtio_transport_set_buffer_size,
689 		.set_min_buffer_size      = virtio_transport_set_min_buffer_size,
690 		.set_max_buffer_size      = virtio_transport_set_max_buffer_size,
691 		.get_buffer_size          = virtio_transport_get_buffer_size,
692 		.get_min_buffer_size      = virtio_transport_get_min_buffer_size,
693 		.get_max_buffer_size      = virtio_transport_get_max_buffer_size,
694 	},
695 
696 	.send_pkt = vhost_transport_send_pkt,
697 };
698 
699 static int __init vhost_vsock_init(void)
700 {
701 	int ret;
702 
703 	ret = vsock_core_init(&vhost_transport.transport);
704 	if (ret < 0)
705 		return ret;
706 	return misc_register(&vhost_vsock_misc);
707 };
708 
709 static void __exit vhost_vsock_exit(void)
710 {
711 	misc_deregister(&vhost_vsock_misc);
712 	vsock_core_exit();
713 };
714 
715 module_init(vhost_vsock_init);
716 module_exit(vhost_vsock_exit);
717 MODULE_LICENSE("GPL v2");
718 MODULE_AUTHOR("Asias He");
719 MODULE_DESCRIPTION("vhost transport for vsock ");
720