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  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * vhost 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#include <linux/miscdevice.h>
 10#include <linux/atomic.h>
 11#include <linux/module.h>
 12#include <linux/mutex.h>
 13#include <linux/vmalloc.h>
 14#include <net/sock.h>
 15#include <linux/virtio_vsock.h>
 16#include <linux/vhost.h>
 17#include <linux/hashtable.h>
 18
 19#include <net/af_vsock.h>
 20#include "vhost.h"
 21
 22#define VHOST_VSOCK_DEFAULT_HOST_CID	2
 23/* Max number of bytes transferred before requeueing the job.
 24 * Using this limit prevents one virtqueue from starving others. */
 25#define VHOST_VSOCK_WEIGHT 0x80000
 26/* Max number of packets transferred before requeueing the job.
 27 * Using this limit prevents one virtqueue from starving others with
 28 * small pkts.
 29 */
 30#define VHOST_VSOCK_PKT_WEIGHT 256
 31
 32enum {
 33	VHOST_VSOCK_FEATURES = VHOST_FEATURES,
 34};
 35
 36/* Used to track all the vhost_vsock instances on the system. */
 37static DEFINE_MUTEX(vhost_vsock_mutex);
 38static DEFINE_READ_MOSTLY_HASHTABLE(vhost_vsock_hash, 8);
 39
 40struct vhost_vsock {
 41	struct vhost_dev dev;
 42	struct vhost_virtqueue vqs[2];
 43
 44	/* Link to global vhost_vsock_hash, writes use vhost_vsock_mutex */
 45	struct hlist_node hash;
 46
 47	struct vhost_work send_pkt_work;
 48	spinlock_t send_pkt_list_lock;
 49	struct list_head send_pkt_list;	/* host->guest pending packets */
 50
 51	atomic_t queued_replies;
 52
 53	u32 guest_cid;
 54};
 55
 56static u32 vhost_transport_get_local_cid(void)
 57{
 58	return VHOST_VSOCK_DEFAULT_HOST_CID;
 59}
 60
 61/* Callers that dereference the return value must hold vhost_vsock_mutex or the
 62 * RCU read lock.
 63 */
 64static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
 65{
 66	struct vhost_vsock *vsock;
 67
 68	hash_for_each_possible_rcu(vhost_vsock_hash, vsock, hash, guest_cid) {
 69		u32 other_cid = vsock->guest_cid;
 70
 71		/* Skip instances that have no CID yet */
 72		if (other_cid == 0)
 73			continue;
 74
 75		if (other_cid == guest_cid)
 76			return vsock;
 77
 78	}
 79
 80	return NULL;
 81}
 82
 83static void
 84vhost_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	int pkts = 0, total_len = 0;
 89	bool added = false;
 90	bool restart_tx = false;
 91
 92	mutex_lock(&vq->mutex);
 93
 94	if (!vq->private_data)
 95		goto out;
 96
 97	/* Avoid further vmexits, we're already processing the virtqueue */
 98	vhost_disable_notify(&vsock->dev, vq);
 99
100	do {
101		struct virtio_vsock_pkt *pkt;
102		struct iov_iter iov_iter;
103		unsigned out, in;
104		size_t nbytes;
105		size_t iov_len, payload_len;
106		int head;
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			vhost_enable_notify(&vsock->dev, vq);
112			break;
113		}
114
115		pkt = list_first_entry(&vsock->send_pkt_list,
116				       struct virtio_vsock_pkt, list);
117		list_del_init(&pkt->list);
118		spin_unlock_bh(&vsock->send_pkt_list_lock);
119
120		head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
121					 &out, &in, NULL, NULL);
122		if (head < 0) {
123			spin_lock_bh(&vsock->send_pkt_list_lock);
124			list_add(&pkt->list, &vsock->send_pkt_list);
125			spin_unlock_bh(&vsock->send_pkt_list_lock);
126			break;
127		}
128
129		if (head == vq->num) {
130			spin_lock_bh(&vsock->send_pkt_list_lock);
131			list_add(&pkt->list, &vsock->send_pkt_list);
132			spin_unlock_bh(&vsock->send_pkt_list_lock);
133
134			/* We cannot finish yet if more buffers snuck in while
135			 * re-enabling notify.
136			 */
137			if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
138				vhost_disable_notify(&vsock->dev, vq);
139				continue;
140			}
141			break;
142		}
143
144		if (out) {
145			virtio_transport_free_pkt(pkt);
146			vq_err(vq, "Expected 0 output buffers, got %u\n", out);
147			break;
148		}
149
150		iov_len = iov_length(&vq->iov[out], in);
151		if (iov_len < sizeof(pkt->hdr)) {
152			virtio_transport_free_pkt(pkt);
153			vq_err(vq, "Buffer len [%zu] too small\n", iov_len);
154			break;
155		}
156
157		iov_iter_init(&iov_iter, READ, &vq->iov[out], in, iov_len);
158		payload_len = pkt->len - pkt->off;
159
160		/* If the packet is greater than the space available in the
161		 * buffer, we split it using multiple buffers.
162		 */
163		if (payload_len > iov_len - sizeof(pkt->hdr))
164			payload_len = iov_len - sizeof(pkt->hdr);
165
166		/* Set the correct length in the header */
167		pkt->hdr.len = cpu_to_le32(payload_len);
168
169		nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
170		if (nbytes != sizeof(pkt->hdr)) {
171			virtio_transport_free_pkt(pkt);
172			vq_err(vq, "Faulted on copying pkt hdr\n");
173			break;
174		}
175
176		nbytes = copy_to_iter(pkt->buf + pkt->off, payload_len,
177				      &iov_iter);
178		if (nbytes != payload_len) {
179			virtio_transport_free_pkt(pkt);
180			vq_err(vq, "Faulted on copying pkt buf\n");
181			break;
182		}
183
184		vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len);
185		added = true;
186
187		/* Deliver to monitoring devices all correctly transmitted
188		 * packets.
189		 */
190		virtio_transport_deliver_tap_pkt(pkt);
191
192		pkt->off += payload_len;
193		total_len += payload_len;
194
195		/* If we didn't send all the payload we can requeue the packet
196		 * to send it with the next available buffer.
197		 */
198		if (pkt->off < pkt->len) {
199			spin_lock_bh(&vsock->send_pkt_list_lock);
200			list_add(&pkt->list, &vsock->send_pkt_list);
201			spin_unlock_bh(&vsock->send_pkt_list_lock);
202		} else {
203			if (pkt->reply) {
204				int val;
205
206				val = atomic_dec_return(&vsock->queued_replies);
207
208				/* Do we have resources to resume tx
209				 * processing?
210				 */
211				if (val + 1 == tx_vq->num)
212					restart_tx = true;
213			}
214
215			virtio_transport_free_pkt(pkt);
216		}
217	} while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
218	if (added)
219		vhost_signal(&vsock->dev, vq);
220
221out:
222	mutex_unlock(&vq->mutex);
223
224	if (restart_tx)
225		vhost_poll_queue(&tx_vq->poll);
226}
227
228static void vhost_transport_send_pkt_work(struct vhost_work *work)
229{
230	struct vhost_virtqueue *vq;
231	struct vhost_vsock *vsock;
232
233	vsock = container_of(work, struct vhost_vsock, send_pkt_work);
234	vq = &vsock->vqs[VSOCK_VQ_RX];
235
236	vhost_transport_do_send_pkt(vsock, vq);
237}
238
239static int
240vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt)
241{
242	struct vhost_vsock *vsock;
243	int len = pkt->len;
244
245	rcu_read_lock();
246
247	/* Find the vhost_vsock according to guest context id  */
248	vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid));
249	if (!vsock) {
250		rcu_read_unlock();
251		virtio_transport_free_pkt(pkt);
252		return -ENODEV;
253	}
254
255	if (pkt->reply)
256		atomic_inc(&vsock->queued_replies);
257
258	spin_lock_bh(&vsock->send_pkt_list_lock);
259	list_add_tail(&pkt->list, &vsock->send_pkt_list);
260	spin_unlock_bh(&vsock->send_pkt_list_lock);
261
262	vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
263
264	rcu_read_unlock();
265	return len;
266}
267
268static int
269vhost_transport_cancel_pkt(struct vsock_sock *vsk)
270{
271	struct vhost_vsock *vsock;
272	struct virtio_vsock_pkt *pkt, *n;
273	int cnt = 0;
274	int ret = -ENODEV;
275	LIST_HEAD(freeme);
276
277	rcu_read_lock();
278
279	/* Find the vhost_vsock according to guest context id  */
280	vsock = vhost_vsock_get(vsk->remote_addr.svm_cid);
281	if (!vsock)
282		goto out;
283
284	spin_lock_bh(&vsock->send_pkt_list_lock);
285	list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
286		if (pkt->vsk != vsk)
287			continue;
288		list_move(&pkt->list, &freeme);
289	}
290	spin_unlock_bh(&vsock->send_pkt_list_lock);
291
292	list_for_each_entry_safe(pkt, n, &freeme, list) {
293		if (pkt->reply)
294			cnt++;
295		list_del(&pkt->list);
296		virtio_transport_free_pkt(pkt);
297	}
298
299	if (cnt) {
300		struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
301		int new_cnt;
302
303		new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
304		if (new_cnt + cnt >= tx_vq->num && new_cnt < tx_vq->num)
305			vhost_poll_queue(&tx_vq->poll);
306	}
307
308	ret = 0;
309out:
310	rcu_read_unlock();
311	return ret;
312}
313
314static struct virtio_vsock_pkt *
315vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
316		      unsigned int out, unsigned int in)
317{
318	struct virtio_vsock_pkt *pkt;
319	struct iov_iter iov_iter;
320	size_t nbytes;
321	size_t len;
322
323	if (in != 0) {
324		vq_err(vq, "Expected 0 input buffers, got %u\n", in);
325		return NULL;
326	}
327
328	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
329	if (!pkt)
330		return NULL;
331
332	len = iov_length(vq->iov, out);
333	iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);
334
335	nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
336	if (nbytes != sizeof(pkt->hdr)) {
337		vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
338		       sizeof(pkt->hdr), nbytes);
339		kfree(pkt);
340		return NULL;
341	}
342
343	if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM)
344		pkt->len = le32_to_cpu(pkt->hdr.len);
345
346	/* No payload */
347	if (!pkt->len)
348		return pkt;
349
350	/* The pkt is too big */
351	if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
352		kfree(pkt);
353		return NULL;
354	}
355
356	pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
357	if (!pkt->buf) {
358		kfree(pkt);
359		return NULL;
360	}
361
362	pkt->buf_len = pkt->len;
363
364	nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
365	if (nbytes != pkt->len) {
366		vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
367		       pkt->len, nbytes);
368		virtio_transport_free_pkt(pkt);
369		return NULL;
370	}
371
372	return pkt;
373}
374
375/* Is there space left for replies to rx packets? */
376static bool vhost_vsock_more_replies(struct vhost_vsock *vsock)
377{
378	struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX];
379	int val;
380
381	smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
382	val = atomic_read(&vsock->queued_replies);
383
384	return val < vq->num;
385}
386
387static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
388{
389	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
390						  poll.work);
391	struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
392						 dev);
393	struct virtio_vsock_pkt *pkt;
394	int head, pkts = 0, total_len = 0;
395	unsigned int out, in;
396	bool added = false;
397
398	mutex_lock(&vq->mutex);
399
400	if (!vq->private_data)
401		goto out;
402
403	vhost_disable_notify(&vsock->dev, vq);
404	do {
405		u32 len;
406
407		if (!vhost_vsock_more_replies(vsock)) {
408			/* Stop tx until the device processes already
409			 * pending replies.  Leave tx virtqueue
410			 * callbacks disabled.
411			 */
412			goto no_more_replies;
413		}
414
415		head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
416					 &out, &in, NULL, NULL);
417		if (head < 0)
418			break;
419
420		if (head == vq->num) {
421			if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
422				vhost_disable_notify(&vsock->dev, vq);
423				continue;
424			}
425			break;
426		}
427
428		pkt = vhost_vsock_alloc_pkt(vq, out, in);
429		if (!pkt) {
430			vq_err(vq, "Faulted on pkt\n");
431			continue;
432		}
433
434		len = pkt->len;
435
436		/* Deliver to monitoring devices all received packets */
437		virtio_transport_deliver_tap_pkt(pkt);
438
439		/* Only accept correctly addressed packets */
440		if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
441			virtio_transport_recv_pkt(pkt);
442		else
443			virtio_transport_free_pkt(pkt);
444
445		len += sizeof(pkt->hdr);
446		vhost_add_used(vq, head, len);
447		total_len += len;
448		added = true;
449	} while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
450
451no_more_replies:
452	if (added)
453		vhost_signal(&vsock->dev, vq);
454
455out:
456	mutex_unlock(&vq->mutex);
457}
458
459static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
460{
461	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
462						poll.work);
463	struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
464						 dev);
465
466	vhost_transport_do_send_pkt(vsock, vq);
467}
468
469static int vhost_vsock_start(struct vhost_vsock *vsock)
470{
471	struct vhost_virtqueue *vq;
472	size_t i;
473	int ret;
474
475	mutex_lock(&vsock->dev.mutex);
476
477	ret = vhost_dev_check_owner(&vsock->dev);
478	if (ret)
479		goto err;
480
481	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
482		vq = &vsock->vqs[i];
483
484		mutex_lock(&vq->mutex);
485
486		if (!vhost_vq_access_ok(vq)) {
487			ret = -EFAULT;
488			goto err_vq;
489		}
490
491		if (!vq->private_data) {
492			vq->private_data = vsock;
493			ret = vhost_vq_init_access(vq);
494			if (ret)
495				goto err_vq;
496		}
497
498		mutex_unlock(&vq->mutex);
499	}
500
501	mutex_unlock(&vsock->dev.mutex);
502	return 0;
503
504err_vq:
505	vq->private_data = NULL;
506	mutex_unlock(&vq->mutex);
507
508	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
509		vq = &vsock->vqs[i];
510
511		mutex_lock(&vq->mutex);
512		vq->private_data = NULL;
513		mutex_unlock(&vq->mutex);
514	}
515err:
516	mutex_unlock(&vsock->dev.mutex);
517	return ret;
518}
519
520static int vhost_vsock_stop(struct vhost_vsock *vsock)
521{
522	size_t i;
523	int ret;
524
525	mutex_lock(&vsock->dev.mutex);
526
527	ret = vhost_dev_check_owner(&vsock->dev);
528	if (ret)
529		goto err;
530
531	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
532		struct vhost_virtqueue *vq = &vsock->vqs[i];
533
534		mutex_lock(&vq->mutex);
535		vq->private_data = NULL;
536		mutex_unlock(&vq->mutex);
537	}
538
539err:
540	mutex_unlock(&vsock->dev.mutex);
541	return ret;
542}
543
544static void vhost_vsock_free(struct vhost_vsock *vsock)
545{
546	kvfree(vsock);
547}
548
549static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
550{
551	struct vhost_virtqueue **vqs;
552	struct vhost_vsock *vsock;
553	int ret;
554
555	/* This struct is large and allocation could fail, fall back to vmalloc
556	 * if there is no other way.
557	 */
558	vsock = kvmalloc(sizeof(*vsock), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
559	if (!vsock)
560		return -ENOMEM;
561
562	vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
563	if (!vqs) {
564		ret = -ENOMEM;
565		goto out;
566	}
567
568	vsock->guest_cid = 0; /* no CID assigned yet */
569
570	atomic_set(&vsock->queued_replies, 0);
571
572	vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
573	vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
574	vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
575	vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
576
577	vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
578		       UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT,
579		       VHOST_VSOCK_WEIGHT);
580
581	file->private_data = vsock;
582	spin_lock_init(&vsock->send_pkt_list_lock);
583	INIT_LIST_HEAD(&vsock->send_pkt_list);
584	vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
585	return 0;
586
587out:
588	vhost_vsock_free(vsock);
589	return ret;
590}
591
592static void vhost_vsock_flush(struct vhost_vsock *vsock)
593{
594	int i;
595
596	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++)
597		if (vsock->vqs[i].handle_kick)
598			vhost_poll_flush(&vsock->vqs[i].poll);
599	vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
600}
601
602static void vhost_vsock_reset_orphans(struct sock *sk)
603{
604	struct vsock_sock *vsk = vsock_sk(sk);
605
606	/* vmci_transport.c doesn't take sk_lock here either.  At least we're
607	 * under vsock_table_lock so the sock cannot disappear while we're
608	 * executing.
609	 */
610
611	/* If the peer is still valid, no need to reset connection */
612	if (vhost_vsock_get(vsk->remote_addr.svm_cid))
613		return;
614
615	/* If the close timeout is pending, let it expire.  This avoids races
616	 * with the timeout callback.
617	 */
618	if (vsk->close_work_scheduled)
619		return;
620
621	sock_set_flag(sk, SOCK_DONE);
622	vsk->peer_shutdown = SHUTDOWN_MASK;
623	sk->sk_state = SS_UNCONNECTED;
624	sk->sk_err = ECONNRESET;
625	sk->sk_error_report(sk);
626}
627
628static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
629{
630	struct vhost_vsock *vsock = file->private_data;
631
632	mutex_lock(&vhost_vsock_mutex);
633	if (vsock->guest_cid)
634		hash_del_rcu(&vsock->hash);
635	mutex_unlock(&vhost_vsock_mutex);
636
637	/* Wait for other CPUs to finish using vsock */
638	synchronize_rcu();
639
640	/* Iterating over all connections for all CIDs to find orphans is
641	 * inefficient.  Room for improvement here. */
642	vsock_for_each_connected_socket(vhost_vsock_reset_orphans);
643
644	vhost_vsock_stop(vsock);
645	vhost_vsock_flush(vsock);
646	vhost_dev_stop(&vsock->dev);
647
648	spin_lock_bh(&vsock->send_pkt_list_lock);
649	while (!list_empty(&vsock->send_pkt_list)) {
650		struct virtio_vsock_pkt *pkt;
651
652		pkt = list_first_entry(&vsock->send_pkt_list,
653				struct virtio_vsock_pkt, list);
654		list_del_init(&pkt->list);
655		virtio_transport_free_pkt(pkt);
656	}
657	spin_unlock_bh(&vsock->send_pkt_list_lock);
658
659	vhost_dev_cleanup(&vsock->dev);
660	kfree(vsock->dev.vqs);
661	vhost_vsock_free(vsock);
662	return 0;
663}
664
665static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
666{
667	struct vhost_vsock *other;
668
669	/* Refuse reserved CIDs */
670	if (guest_cid <= VMADDR_CID_HOST ||
671	    guest_cid == U32_MAX)
672		return -EINVAL;
673
674	/* 64-bit CIDs are not yet supported */
675	if (guest_cid > U32_MAX)
676		return -EINVAL;
677
678	/* Refuse if CID is already in use */
679	mutex_lock(&vhost_vsock_mutex);
680	other = vhost_vsock_get(guest_cid);
681	if (other && other != vsock) {
682		mutex_unlock(&vhost_vsock_mutex);
683		return -EADDRINUSE;
684	}
685
686	if (vsock->guest_cid)
687		hash_del_rcu(&vsock->hash);
688
689	vsock->guest_cid = guest_cid;
690	hash_add_rcu(vhost_vsock_hash, &vsock->hash, vsock->guest_cid);
691	mutex_unlock(&vhost_vsock_mutex);
692
693	return 0;
694}
695
696static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
697{
698	struct vhost_virtqueue *vq;
699	int i;
700
701	if (features & ~VHOST_VSOCK_FEATURES)
702		return -EOPNOTSUPP;
703
704	mutex_lock(&vsock->dev.mutex);
705	if ((features & (1 << VHOST_F_LOG_ALL)) &&
706	    !vhost_log_access_ok(&vsock->dev)) {
707		mutex_unlock(&vsock->dev.mutex);
708		return -EFAULT;
709	}
710
711	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
712		vq = &vsock->vqs[i];
713		mutex_lock(&vq->mutex);
714		vq->acked_features = features;
715		mutex_unlock(&vq->mutex);
716	}
717	mutex_unlock(&vsock->dev.mutex);
718	return 0;
719}
720
721static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
722				  unsigned long arg)
723{
724	struct vhost_vsock *vsock = f->private_data;
725	void __user *argp = (void __user *)arg;
726	u64 guest_cid;
727	u64 features;
728	int start;
729	int r;
730
731	switch (ioctl) {
732	case VHOST_VSOCK_SET_GUEST_CID:
733		if (copy_from_user(&guest_cid, argp, sizeof(guest_cid)))
734			return -EFAULT;
735		return vhost_vsock_set_cid(vsock, guest_cid);
736	case VHOST_VSOCK_SET_RUNNING:
737		if (copy_from_user(&start, argp, sizeof(start)))
738			return -EFAULT;
739		if (start)
740			return vhost_vsock_start(vsock);
741		else
742			return vhost_vsock_stop(vsock);
743	case VHOST_GET_FEATURES:
744		features = VHOST_VSOCK_FEATURES;
745		if (copy_to_user(argp, &features, sizeof(features)))
746			return -EFAULT;
747		return 0;
748	case VHOST_SET_FEATURES:
749		if (copy_from_user(&features, argp, sizeof(features)))
750			return -EFAULT;
751		return vhost_vsock_set_features(vsock, features);
752	default:
753		mutex_lock(&vsock->dev.mutex);
754		r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
755		if (r == -ENOIOCTLCMD)
756			r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
757		else
758			vhost_vsock_flush(vsock);
759		mutex_unlock(&vsock->dev.mutex);
760		return r;
761	}
762}
763
764#ifdef CONFIG_COMPAT
765static long vhost_vsock_dev_compat_ioctl(struct file *f, unsigned int ioctl,
766					 unsigned long arg)
767{
768	return vhost_vsock_dev_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
769}
770#endif
771
772static const struct file_operations vhost_vsock_fops = {
773	.owner          = THIS_MODULE,
774	.open           = vhost_vsock_dev_open,
775	.release        = vhost_vsock_dev_release,
776	.llseek		= noop_llseek,
777	.unlocked_ioctl = vhost_vsock_dev_ioctl,
778#ifdef CONFIG_COMPAT
779	.compat_ioctl   = vhost_vsock_dev_compat_ioctl,
780#endif
781};
782
783static struct miscdevice vhost_vsock_misc = {
784	.minor = VHOST_VSOCK_MINOR,
785	.name = "vhost-vsock",
786	.fops = &vhost_vsock_fops,
787};
788
789static struct virtio_transport vhost_transport = {
790	.transport = {
791		.get_local_cid            = vhost_transport_get_local_cid,
792
793		.init                     = virtio_transport_do_socket_init,
794		.destruct                 = virtio_transport_destruct,
795		.release                  = virtio_transport_release,
796		.connect                  = virtio_transport_connect,
797		.shutdown                 = virtio_transport_shutdown,
798		.cancel_pkt               = vhost_transport_cancel_pkt,
799
800		.dgram_enqueue            = virtio_transport_dgram_enqueue,
801		.dgram_dequeue            = virtio_transport_dgram_dequeue,
802		.dgram_bind               = virtio_transport_dgram_bind,
803		.dgram_allow              = virtio_transport_dgram_allow,
804
805		.stream_enqueue           = virtio_transport_stream_enqueue,
806		.stream_dequeue           = virtio_transport_stream_dequeue,
807		.stream_has_data          = virtio_transport_stream_has_data,
808		.stream_has_space         = virtio_transport_stream_has_space,
809		.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
810		.stream_is_active         = virtio_transport_stream_is_active,
811		.stream_allow             = virtio_transport_stream_allow,
812
813		.notify_poll_in           = virtio_transport_notify_poll_in,
814		.notify_poll_out          = virtio_transport_notify_poll_out,
815		.notify_recv_init         = virtio_transport_notify_recv_init,
816		.notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
817		.notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
818		.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
819		.notify_send_init         = virtio_transport_notify_send_init,
820		.notify_send_pre_block    = virtio_transport_notify_send_pre_block,
821		.notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
822		.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
823
824		.set_buffer_size          = virtio_transport_set_buffer_size,
825		.set_min_buffer_size      = virtio_transport_set_min_buffer_size,
826		.set_max_buffer_size      = virtio_transport_set_max_buffer_size,
827		.get_buffer_size          = virtio_transport_get_buffer_size,
828		.get_min_buffer_size      = virtio_transport_get_min_buffer_size,
829		.get_max_buffer_size      = virtio_transport_get_max_buffer_size,
830	},
831
832	.send_pkt = vhost_transport_send_pkt,
833};
834
835static int __init vhost_vsock_init(void)
836{
837	int ret;
838
839	ret = vsock_core_init(&vhost_transport.transport);
840	if (ret < 0)
841		return ret;
842	return misc_register(&vhost_vsock_misc);
843};
844
845static void __exit vhost_vsock_exit(void)
846{
847	misc_deregister(&vhost_vsock_misc);
848	vsock_core_exit();
849};
850
851module_init(vhost_vsock_init);
852module_exit(vhost_vsock_exit);
853MODULE_LICENSE("GPL v2");
854MODULE_AUTHOR("Asias He");
855MODULE_DESCRIPTION("vhost transport for vsock ");
856MODULE_ALIAS_MISCDEV(VHOST_VSOCK_MINOR);
857MODULE_ALIAS("devname:vhost-vsock");