xref: /openbmc/linux/drivers/vhost/vsock.c (revision 6d99a79c)
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 	list_for_each_entry(vsock, &vhost_vsock_list, list) {
58 		u32 other_cid = vsock->guest_cid;
59 
60 		/* Skip instances that have no CID yet */
61 		if (other_cid == 0)
62 			continue;
63 
64 		if (other_cid == guest_cid)
65 			return vsock;
66 
67 	}
68 
69 	return NULL;
70 }
71 
72 static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
73 {
74 	struct vhost_vsock *vsock;
75 
76 	spin_lock_bh(&vhost_vsock_lock);
77 	vsock = __vhost_vsock_get(guest_cid);
78 	spin_unlock_bh(&vhost_vsock_lock);
79 
80 	return vsock;
81 }
82 
83 static void
84 vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
85 			    struct vhost_virtqueue *vq)
86 {
87 	struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
88 	bool added = false;
89 	bool restart_tx = false;
90 
91 	mutex_lock(&vq->mutex);
92 
93 	if (!vq->private_data)
94 		goto out;
95 
96 	/* Avoid further vmexits, we're already processing the virtqueue */
97 	vhost_disable_notify(&vsock->dev, vq);
98 
99 	for (;;) {
100 		struct virtio_vsock_pkt *pkt;
101 		struct iov_iter iov_iter;
102 		unsigned out, in;
103 		size_t nbytes;
104 		size_t len;
105 		int head;
106 
107 		spin_lock_bh(&vsock->send_pkt_list_lock);
108 		if (list_empty(&vsock->send_pkt_list)) {
109 			spin_unlock_bh(&vsock->send_pkt_list_lock);
110 			vhost_enable_notify(&vsock->dev, vq);
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 		head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
120 					 &out, &in, NULL, NULL);
121 		if (head < 0) {
122 			spin_lock_bh(&vsock->send_pkt_list_lock);
123 			list_add(&pkt->list, &vsock->send_pkt_list);
124 			spin_unlock_bh(&vsock->send_pkt_list_lock);
125 			break;
126 		}
127 
128 		if (head == vq->num) {
129 			spin_lock_bh(&vsock->send_pkt_list_lock);
130 			list_add(&pkt->list, &vsock->send_pkt_list);
131 			spin_unlock_bh(&vsock->send_pkt_list_lock);
132 
133 			/* We cannot finish yet if more buffers snuck in while
134 			 * re-enabling notify.
135 			 */
136 			if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
137 				vhost_disable_notify(&vsock->dev, vq);
138 				continue;
139 			}
140 			break;
141 		}
142 
143 		if (out) {
144 			virtio_transport_free_pkt(pkt);
145 			vq_err(vq, "Expected 0 output buffers, got %u\n", out);
146 			break;
147 		}
148 
149 		len = iov_length(&vq->iov[out], in);
150 		iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len);
151 
152 		nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
153 		if (nbytes != sizeof(pkt->hdr)) {
154 			virtio_transport_free_pkt(pkt);
155 			vq_err(vq, "Faulted on copying pkt hdr\n");
156 			break;
157 		}
158 
159 		nbytes = copy_to_iter(pkt->buf, pkt->len, &iov_iter);
160 		if (nbytes != pkt->len) {
161 			virtio_transport_free_pkt(pkt);
162 			vq_err(vq, "Faulted on copying pkt buf\n");
163 			break;
164 		}
165 
166 		vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
167 		added = true;
168 
169 		if (pkt->reply) {
170 			int val;
171 
172 			val = atomic_dec_return(&vsock->queued_replies);
173 
174 			/* Do we have resources to resume tx processing? */
175 			if (val + 1 == tx_vq->num)
176 				restart_tx = true;
177 		}
178 
179 		/* Deliver to monitoring devices all correctly transmitted
180 		 * packets.
181 		 */
182 		virtio_transport_deliver_tap_pkt(pkt);
183 
184 		virtio_transport_free_pkt(pkt);
185 	}
186 	if (added)
187 		vhost_signal(&vsock->dev, vq);
188 
189 out:
190 	mutex_unlock(&vq->mutex);
191 
192 	if (restart_tx)
193 		vhost_poll_queue(&tx_vq->poll);
194 }
195 
196 static void vhost_transport_send_pkt_work(struct vhost_work *work)
197 {
198 	struct vhost_virtqueue *vq;
199 	struct vhost_vsock *vsock;
200 
201 	vsock = container_of(work, struct vhost_vsock, send_pkt_work);
202 	vq = &vsock->vqs[VSOCK_VQ_RX];
203 
204 	vhost_transport_do_send_pkt(vsock, vq);
205 }
206 
207 static int
208 vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt)
209 {
210 	struct vhost_vsock *vsock;
211 	int len = pkt->len;
212 
213 	/* Find the vhost_vsock according to guest context id  */
214 	vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid));
215 	if (!vsock) {
216 		virtio_transport_free_pkt(pkt);
217 		return -ENODEV;
218 	}
219 
220 	if (pkt->reply)
221 		atomic_inc(&vsock->queued_replies);
222 
223 	spin_lock_bh(&vsock->send_pkt_list_lock);
224 	list_add_tail(&pkt->list, &vsock->send_pkt_list);
225 	spin_unlock_bh(&vsock->send_pkt_list_lock);
226 
227 	vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
228 	return len;
229 }
230 
231 static int
232 vhost_transport_cancel_pkt(struct vsock_sock *vsk)
233 {
234 	struct vhost_vsock *vsock;
235 	struct virtio_vsock_pkt *pkt, *n;
236 	int cnt = 0;
237 	LIST_HEAD(freeme);
238 
239 	/* Find the vhost_vsock according to guest context id  */
240 	vsock = vhost_vsock_get(vsk->remote_addr.svm_cid);
241 	if (!vsock)
242 		return -ENODEV;
243 
244 	spin_lock_bh(&vsock->send_pkt_list_lock);
245 	list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
246 		if (pkt->vsk != vsk)
247 			continue;
248 		list_move(&pkt->list, &freeme);
249 	}
250 	spin_unlock_bh(&vsock->send_pkt_list_lock);
251 
252 	list_for_each_entry_safe(pkt, n, &freeme, list) {
253 		if (pkt->reply)
254 			cnt++;
255 		list_del(&pkt->list);
256 		virtio_transport_free_pkt(pkt);
257 	}
258 
259 	if (cnt) {
260 		struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
261 		int new_cnt;
262 
263 		new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
264 		if (new_cnt + cnt >= tx_vq->num && new_cnt < tx_vq->num)
265 			vhost_poll_queue(&tx_vq->poll);
266 	}
267 
268 	return 0;
269 }
270 
271 static struct virtio_vsock_pkt *
272 vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
273 		      unsigned int out, unsigned int in)
274 {
275 	struct virtio_vsock_pkt *pkt;
276 	struct iov_iter iov_iter;
277 	size_t nbytes;
278 	size_t len;
279 
280 	if (in != 0) {
281 		vq_err(vq, "Expected 0 input buffers, got %u\n", in);
282 		return NULL;
283 	}
284 
285 	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
286 	if (!pkt)
287 		return NULL;
288 
289 	len = iov_length(vq->iov, out);
290 	iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);
291 
292 	nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
293 	if (nbytes != sizeof(pkt->hdr)) {
294 		vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
295 		       sizeof(pkt->hdr), nbytes);
296 		kfree(pkt);
297 		return NULL;
298 	}
299 
300 	if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM)
301 		pkt->len = le32_to_cpu(pkt->hdr.len);
302 
303 	/* No payload */
304 	if (!pkt->len)
305 		return pkt;
306 
307 	/* The pkt is too big */
308 	if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
309 		kfree(pkt);
310 		return NULL;
311 	}
312 
313 	pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
314 	if (!pkt->buf) {
315 		kfree(pkt);
316 		return NULL;
317 	}
318 
319 	nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
320 	if (nbytes != pkt->len) {
321 		vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
322 		       pkt->len, nbytes);
323 		virtio_transport_free_pkt(pkt);
324 		return NULL;
325 	}
326 
327 	return pkt;
328 }
329 
330 /* Is there space left for replies to rx packets? */
331 static bool vhost_vsock_more_replies(struct vhost_vsock *vsock)
332 {
333 	struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX];
334 	int val;
335 
336 	smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
337 	val = atomic_read(&vsock->queued_replies);
338 
339 	return val < vq->num;
340 }
341 
342 static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
343 {
344 	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
345 						  poll.work);
346 	struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
347 						 dev);
348 	struct virtio_vsock_pkt *pkt;
349 	int head;
350 	unsigned int out, in;
351 	bool added = false;
352 
353 	mutex_lock(&vq->mutex);
354 
355 	if (!vq->private_data)
356 		goto out;
357 
358 	vhost_disable_notify(&vsock->dev, vq);
359 	for (;;) {
360 		u32 len;
361 
362 		if (!vhost_vsock_more_replies(vsock)) {
363 			/* Stop tx until the device processes already
364 			 * pending replies.  Leave tx virtqueue
365 			 * callbacks disabled.
366 			 */
367 			goto no_more_replies;
368 		}
369 
370 		head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
371 					 &out, &in, NULL, NULL);
372 		if (head < 0)
373 			break;
374 
375 		if (head == vq->num) {
376 			if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
377 				vhost_disable_notify(&vsock->dev, vq);
378 				continue;
379 			}
380 			break;
381 		}
382 
383 		pkt = vhost_vsock_alloc_pkt(vq, out, in);
384 		if (!pkt) {
385 			vq_err(vq, "Faulted on pkt\n");
386 			continue;
387 		}
388 
389 		len = pkt->len;
390 
391 		/* Deliver to monitoring devices all received packets */
392 		virtio_transport_deliver_tap_pkt(pkt);
393 
394 		/* Only accept correctly addressed packets */
395 		if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
396 			virtio_transport_recv_pkt(pkt);
397 		else
398 			virtio_transport_free_pkt(pkt);
399 
400 		vhost_add_used(vq, head, sizeof(pkt->hdr) + len);
401 		added = true;
402 	}
403 
404 no_more_replies:
405 	if (added)
406 		vhost_signal(&vsock->dev, vq);
407 
408 out:
409 	mutex_unlock(&vq->mutex);
410 }
411 
412 static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
413 {
414 	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
415 						poll.work);
416 	struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
417 						 dev);
418 
419 	vhost_transport_do_send_pkt(vsock, vq);
420 }
421 
422 static int vhost_vsock_start(struct vhost_vsock *vsock)
423 {
424 	struct vhost_virtqueue *vq;
425 	size_t i;
426 	int ret;
427 
428 	mutex_lock(&vsock->dev.mutex);
429 
430 	ret = vhost_dev_check_owner(&vsock->dev);
431 	if (ret)
432 		goto err;
433 
434 	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
435 		vq = &vsock->vqs[i];
436 
437 		mutex_lock(&vq->mutex);
438 
439 		if (!vhost_vq_access_ok(vq)) {
440 			ret = -EFAULT;
441 			goto err_vq;
442 		}
443 
444 		if (!vq->private_data) {
445 			vq->private_data = vsock;
446 			ret = vhost_vq_init_access(vq);
447 			if (ret)
448 				goto err_vq;
449 		}
450 
451 		mutex_unlock(&vq->mutex);
452 	}
453 
454 	mutex_unlock(&vsock->dev.mutex);
455 	return 0;
456 
457 err_vq:
458 	vq->private_data = NULL;
459 	mutex_unlock(&vq->mutex);
460 
461 	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
462 		vq = &vsock->vqs[i];
463 
464 		mutex_lock(&vq->mutex);
465 		vq->private_data = NULL;
466 		mutex_unlock(&vq->mutex);
467 	}
468 err:
469 	mutex_unlock(&vsock->dev.mutex);
470 	return ret;
471 }
472 
473 static int vhost_vsock_stop(struct vhost_vsock *vsock)
474 {
475 	size_t i;
476 	int ret;
477 
478 	mutex_lock(&vsock->dev.mutex);
479 
480 	ret = vhost_dev_check_owner(&vsock->dev);
481 	if (ret)
482 		goto err;
483 
484 	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
485 		struct vhost_virtqueue *vq = &vsock->vqs[i];
486 
487 		mutex_lock(&vq->mutex);
488 		vq->private_data = NULL;
489 		mutex_unlock(&vq->mutex);
490 	}
491 
492 err:
493 	mutex_unlock(&vsock->dev.mutex);
494 	return ret;
495 }
496 
497 static void vhost_vsock_free(struct vhost_vsock *vsock)
498 {
499 	kvfree(vsock);
500 }
501 
502 static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
503 {
504 	struct vhost_virtqueue **vqs;
505 	struct vhost_vsock *vsock;
506 	int ret;
507 
508 	/* This struct is large and allocation could fail, fall back to vmalloc
509 	 * if there is no other way.
510 	 */
511 	vsock = kvmalloc(sizeof(*vsock), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
512 	if (!vsock)
513 		return -ENOMEM;
514 
515 	vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
516 	if (!vqs) {
517 		ret = -ENOMEM;
518 		goto out;
519 	}
520 
521 	vsock->guest_cid = 0; /* no CID assigned yet */
522 
523 	atomic_set(&vsock->queued_replies, 0);
524 
525 	vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
526 	vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
527 	vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
528 	vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
529 
530 	vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs));
531 
532 	file->private_data = vsock;
533 	spin_lock_init(&vsock->send_pkt_list_lock);
534 	INIT_LIST_HEAD(&vsock->send_pkt_list);
535 	vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
536 
537 	spin_lock_bh(&vhost_vsock_lock);
538 	list_add_tail(&vsock->list, &vhost_vsock_list);
539 	spin_unlock_bh(&vhost_vsock_lock);
540 	return 0;
541 
542 out:
543 	vhost_vsock_free(vsock);
544 	return ret;
545 }
546 
547 static void vhost_vsock_flush(struct vhost_vsock *vsock)
548 {
549 	int i;
550 
551 	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++)
552 		if (vsock->vqs[i].handle_kick)
553 			vhost_poll_flush(&vsock->vqs[i].poll);
554 	vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
555 }
556 
557 static void vhost_vsock_reset_orphans(struct sock *sk)
558 {
559 	struct vsock_sock *vsk = vsock_sk(sk);
560 
561 	/* vmci_transport.c doesn't take sk_lock here either.  At least we're
562 	 * under vsock_table_lock so the sock cannot disappear while we're
563 	 * executing.
564 	 */
565 
566 	if (!vhost_vsock_get(vsk->remote_addr.svm_cid)) {
567 		sock_set_flag(sk, SOCK_DONE);
568 		vsk->peer_shutdown = SHUTDOWN_MASK;
569 		sk->sk_state = SS_UNCONNECTED;
570 		sk->sk_err = ECONNRESET;
571 		sk->sk_error_report(sk);
572 	}
573 }
574 
575 static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
576 {
577 	struct vhost_vsock *vsock = file->private_data;
578 
579 	spin_lock_bh(&vhost_vsock_lock);
580 	list_del(&vsock->list);
581 	spin_unlock_bh(&vhost_vsock_lock);
582 
583 	/* Iterating over all connections for all CIDs to find orphans is
584 	 * inefficient.  Room for improvement here. */
585 	vsock_for_each_connected_socket(vhost_vsock_reset_orphans);
586 
587 	vhost_vsock_stop(vsock);
588 	vhost_vsock_flush(vsock);
589 	vhost_dev_stop(&vsock->dev);
590 
591 	spin_lock_bh(&vsock->send_pkt_list_lock);
592 	while (!list_empty(&vsock->send_pkt_list)) {
593 		struct virtio_vsock_pkt *pkt;
594 
595 		pkt = list_first_entry(&vsock->send_pkt_list,
596 				struct virtio_vsock_pkt, list);
597 		list_del_init(&pkt->list);
598 		virtio_transport_free_pkt(pkt);
599 	}
600 	spin_unlock_bh(&vsock->send_pkt_list_lock);
601 
602 	vhost_dev_cleanup(&vsock->dev);
603 	kfree(vsock->dev.vqs);
604 	vhost_vsock_free(vsock);
605 	return 0;
606 }
607 
608 static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
609 {
610 	struct vhost_vsock *other;
611 
612 	/* Refuse reserved CIDs */
613 	if (guest_cid <= VMADDR_CID_HOST ||
614 	    guest_cid == U32_MAX)
615 		return -EINVAL;
616 
617 	/* 64-bit CIDs are not yet supported */
618 	if (guest_cid > U32_MAX)
619 		return -EINVAL;
620 
621 	/* Refuse if CID is already in use */
622 	spin_lock_bh(&vhost_vsock_lock);
623 	other = __vhost_vsock_get(guest_cid);
624 	if (other && other != vsock) {
625 		spin_unlock_bh(&vhost_vsock_lock);
626 		return -EADDRINUSE;
627 	}
628 	vsock->guest_cid = guest_cid;
629 	spin_unlock_bh(&vhost_vsock_lock);
630 
631 	return 0;
632 }
633 
634 static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
635 {
636 	struct vhost_virtqueue *vq;
637 	int i;
638 
639 	if (features & ~VHOST_VSOCK_FEATURES)
640 		return -EOPNOTSUPP;
641 
642 	mutex_lock(&vsock->dev.mutex);
643 	if ((features & (1 << VHOST_F_LOG_ALL)) &&
644 	    !vhost_log_access_ok(&vsock->dev)) {
645 		mutex_unlock(&vsock->dev.mutex);
646 		return -EFAULT;
647 	}
648 
649 	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
650 		vq = &vsock->vqs[i];
651 		mutex_lock(&vq->mutex);
652 		vq->acked_features = features;
653 		mutex_unlock(&vq->mutex);
654 	}
655 	mutex_unlock(&vsock->dev.mutex);
656 	return 0;
657 }
658 
659 static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
660 				  unsigned long arg)
661 {
662 	struct vhost_vsock *vsock = f->private_data;
663 	void __user *argp = (void __user *)arg;
664 	u64 guest_cid;
665 	u64 features;
666 	int start;
667 	int r;
668 
669 	switch (ioctl) {
670 	case VHOST_VSOCK_SET_GUEST_CID:
671 		if (copy_from_user(&guest_cid, argp, sizeof(guest_cid)))
672 			return -EFAULT;
673 		return vhost_vsock_set_cid(vsock, guest_cid);
674 	case VHOST_VSOCK_SET_RUNNING:
675 		if (copy_from_user(&start, argp, sizeof(start)))
676 			return -EFAULT;
677 		if (start)
678 			return vhost_vsock_start(vsock);
679 		else
680 			return vhost_vsock_stop(vsock);
681 	case VHOST_GET_FEATURES:
682 		features = VHOST_VSOCK_FEATURES;
683 		if (copy_to_user(argp, &features, sizeof(features)))
684 			return -EFAULT;
685 		return 0;
686 	case VHOST_SET_FEATURES:
687 		if (copy_from_user(&features, argp, sizeof(features)))
688 			return -EFAULT;
689 		return vhost_vsock_set_features(vsock, features);
690 	default:
691 		mutex_lock(&vsock->dev.mutex);
692 		r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
693 		if (r == -ENOIOCTLCMD)
694 			r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
695 		else
696 			vhost_vsock_flush(vsock);
697 		mutex_unlock(&vsock->dev.mutex);
698 		return r;
699 	}
700 }
701 
702 #ifdef CONFIG_COMPAT
703 static long vhost_vsock_dev_compat_ioctl(struct file *f, unsigned int ioctl,
704 					 unsigned long arg)
705 {
706 	return vhost_vsock_dev_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
707 }
708 #endif
709 
710 static const struct file_operations vhost_vsock_fops = {
711 	.owner          = THIS_MODULE,
712 	.open           = vhost_vsock_dev_open,
713 	.release        = vhost_vsock_dev_release,
714 	.llseek		= noop_llseek,
715 	.unlocked_ioctl = vhost_vsock_dev_ioctl,
716 #ifdef CONFIG_COMPAT
717 	.compat_ioctl   = vhost_vsock_dev_compat_ioctl,
718 #endif
719 };
720 
721 static struct miscdevice vhost_vsock_misc = {
722 	.minor = VHOST_VSOCK_MINOR,
723 	.name = "vhost-vsock",
724 	.fops = &vhost_vsock_fops,
725 };
726 
727 static struct virtio_transport vhost_transport = {
728 	.transport = {
729 		.get_local_cid            = vhost_transport_get_local_cid,
730 
731 		.init                     = virtio_transport_do_socket_init,
732 		.destruct                 = virtio_transport_destruct,
733 		.release                  = virtio_transport_release,
734 		.connect                  = virtio_transport_connect,
735 		.shutdown                 = virtio_transport_shutdown,
736 		.cancel_pkt               = vhost_transport_cancel_pkt,
737 
738 		.dgram_enqueue            = virtio_transport_dgram_enqueue,
739 		.dgram_dequeue            = virtio_transport_dgram_dequeue,
740 		.dgram_bind               = virtio_transport_dgram_bind,
741 		.dgram_allow              = virtio_transport_dgram_allow,
742 
743 		.stream_enqueue           = virtio_transport_stream_enqueue,
744 		.stream_dequeue           = virtio_transport_stream_dequeue,
745 		.stream_has_data          = virtio_transport_stream_has_data,
746 		.stream_has_space         = virtio_transport_stream_has_space,
747 		.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
748 		.stream_is_active         = virtio_transport_stream_is_active,
749 		.stream_allow             = virtio_transport_stream_allow,
750 
751 		.notify_poll_in           = virtio_transport_notify_poll_in,
752 		.notify_poll_out          = virtio_transport_notify_poll_out,
753 		.notify_recv_init         = virtio_transport_notify_recv_init,
754 		.notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
755 		.notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
756 		.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
757 		.notify_send_init         = virtio_transport_notify_send_init,
758 		.notify_send_pre_block    = virtio_transport_notify_send_pre_block,
759 		.notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
760 		.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
761 
762 		.set_buffer_size          = virtio_transport_set_buffer_size,
763 		.set_min_buffer_size      = virtio_transport_set_min_buffer_size,
764 		.set_max_buffer_size      = virtio_transport_set_max_buffer_size,
765 		.get_buffer_size          = virtio_transport_get_buffer_size,
766 		.get_min_buffer_size      = virtio_transport_get_min_buffer_size,
767 		.get_max_buffer_size      = virtio_transport_get_max_buffer_size,
768 	},
769 
770 	.send_pkt = vhost_transport_send_pkt,
771 };
772 
773 static int __init vhost_vsock_init(void)
774 {
775 	int ret;
776 
777 	ret = vsock_core_init(&vhost_transport.transport);
778 	if (ret < 0)
779 		return ret;
780 	return misc_register(&vhost_vsock_misc);
781 };
782 
783 static void __exit vhost_vsock_exit(void)
784 {
785 	misc_deregister(&vhost_vsock_misc);
786 	vsock_core_exit();
787 };
788 
789 module_init(vhost_vsock_init);
790 module_exit(vhost_vsock_exit);
791 MODULE_LICENSE("GPL v2");
792 MODULE_AUTHOR("Asias He");
793 MODULE_DESCRIPTION("vhost transport for vsock ");
794 MODULE_ALIAS_MISCDEV(VHOST_VSOCK_MINOR);
795 MODULE_ALIAS("devname:vhost-vsock");
796