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 #include <linux/hashtable.h>
19
20 #include <net/af_vsock.h>
21 #include "vhost.h"
22
23 #define VHOST_VSOCK_DEFAULT_HOST_CID 2
24 /* Max number of bytes transferred before requeueing the job.
25 * Using this limit prevents one virtqueue from starving others. */
26 #define VHOST_VSOCK_WEIGHT 0x80000
27 /* Max number of packets transferred before requeueing the job.
28 * Using this limit prevents one virtqueue from starving others with
29 * small pkts.
30 */
31 #define VHOST_VSOCK_PKT_WEIGHT 256
32
33 enum {
34 VHOST_VSOCK_FEATURES = VHOST_FEATURES,
35 };
36
37 /* Used to track all the vhost_vsock instances on the system. */
38 static DEFINE_SPINLOCK(vhost_vsock_lock);
39 static DEFINE_READ_MOSTLY_HASHTABLE(vhost_vsock_hash, 8);
40
41 struct vhost_vsock {
42 struct vhost_dev dev;
43 struct vhost_virtqueue vqs[2];
44
45 /* Link to global vhost_vsock_hash, writes use vhost_vsock_lock */
46 struct hlist_node hash;
47
48 struct vhost_work send_pkt_work;
49 spinlock_t send_pkt_list_lock;
50 struct list_head send_pkt_list; /* host->guest pending packets */
51
52 atomic_t queued_replies;
53
54 u32 guest_cid;
55 };
56
vhost_transport_get_local_cid(void)57 static u32 vhost_transport_get_local_cid(void)
58 {
59 return VHOST_VSOCK_DEFAULT_HOST_CID;
60 }
61
62 /* Callers that dereference the return value must hold vhost_vsock_lock or the
63 * RCU read lock.
64 */
vhost_vsock_get(u32 guest_cid)65 static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
66 {
67 struct vhost_vsock *vsock;
68
69 hash_for_each_possible_rcu(vhost_vsock_hash, vsock, hash, guest_cid) {
70 u32 other_cid = vsock->guest_cid;
71
72 /* Skip instances that have no CID yet */
73 if (other_cid == 0)
74 continue;
75
76 if (other_cid == guest_cid)
77 return vsock;
78
79 }
80
81 return NULL;
82 }
83
84 static void
vhost_transport_do_send_pkt(struct vhost_vsock * vsock,struct vhost_virtqueue * vq)85 vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
86 struct vhost_virtqueue *vq)
87 {
88 struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
89 int pkts = 0, total_len = 0;
90 bool added = false;
91 bool restart_tx = false;
92
93 mutex_lock(&vq->mutex);
94
95 if (!vq->private_data)
96 goto out;
97
98 /* Avoid further vmexits, we're already processing the virtqueue */
99 vhost_disable_notify(&vsock->dev, vq);
100
101 do {
102 struct virtio_vsock_pkt *pkt;
103 struct iov_iter iov_iter;
104 unsigned out, in;
105 size_t nbytes;
106 size_t iov_len, payload_len;
107 int head;
108
109 spin_lock_bh(&vsock->send_pkt_list_lock);
110 if (list_empty(&vsock->send_pkt_list)) {
111 spin_unlock_bh(&vsock->send_pkt_list_lock);
112 vhost_enable_notify(&vsock->dev, vq);
113 break;
114 }
115
116 pkt = list_first_entry(&vsock->send_pkt_list,
117 struct virtio_vsock_pkt, list);
118 list_del_init(&pkt->list);
119 spin_unlock_bh(&vsock->send_pkt_list_lock);
120
121 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
122 &out, &in, NULL, NULL);
123 if (head < 0) {
124 spin_lock_bh(&vsock->send_pkt_list_lock);
125 list_add(&pkt->list, &vsock->send_pkt_list);
126 spin_unlock_bh(&vsock->send_pkt_list_lock);
127 break;
128 }
129
130 if (head == vq->num) {
131 spin_lock_bh(&vsock->send_pkt_list_lock);
132 list_add(&pkt->list, &vsock->send_pkt_list);
133 spin_unlock_bh(&vsock->send_pkt_list_lock);
134
135 /* We cannot finish yet if more buffers snuck in while
136 * re-enabling notify.
137 */
138 if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
139 vhost_disable_notify(&vsock->dev, vq);
140 continue;
141 }
142 break;
143 }
144
145 if (out) {
146 virtio_transport_free_pkt(pkt);
147 vq_err(vq, "Expected 0 output buffers, got %u\n", out);
148 break;
149 }
150
151 iov_len = iov_length(&vq->iov[out], in);
152 if (iov_len < sizeof(pkt->hdr)) {
153 virtio_transport_free_pkt(pkt);
154 vq_err(vq, "Buffer len [%zu] too small\n", iov_len);
155 break;
156 }
157
158 iov_iter_init(&iov_iter, READ, &vq->iov[out], in, iov_len);
159 payload_len = pkt->len - pkt->off;
160
161 /* If the packet is greater than the space available in the
162 * buffer, we split it using multiple buffers.
163 */
164 if (payload_len > iov_len - sizeof(pkt->hdr))
165 payload_len = iov_len - sizeof(pkt->hdr);
166
167 /* Set the correct length in the header */
168 pkt->hdr.len = cpu_to_le32(payload_len);
169
170 nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
171 if (nbytes != sizeof(pkt->hdr)) {
172 virtio_transport_free_pkt(pkt);
173 vq_err(vq, "Faulted on copying pkt hdr\n");
174 break;
175 }
176
177 nbytes = copy_to_iter(pkt->buf + pkt->off, payload_len,
178 &iov_iter);
179 if (nbytes != payload_len) {
180 virtio_transport_free_pkt(pkt);
181 vq_err(vq, "Faulted on copying pkt buf\n");
182 break;
183 }
184
185 /* Deliver to monitoring devices all packets that we
186 * will transmit.
187 */
188 virtio_transport_deliver_tap_pkt(pkt);
189
190 vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len);
191 added = true;
192
193 pkt->off += payload_len;
194 total_len += payload_len;
195
196 /* If we didn't send all the payload we can requeue the packet
197 * to send it with the next available buffer.
198 */
199 if (pkt->off < pkt->len) {
200 spin_lock_bh(&vsock->send_pkt_list_lock);
201 list_add(&pkt->list, &vsock->send_pkt_list);
202 spin_unlock_bh(&vsock->send_pkt_list_lock);
203 } else {
204 if (pkt->reply) {
205 int val;
206
207 val = atomic_dec_return(&vsock->queued_replies);
208
209 /* Do we have resources to resume tx
210 * processing?
211 */
212 if (val + 1 == tx_vq->num)
213 restart_tx = true;
214 }
215
216 virtio_transport_free_pkt(pkt);
217 }
218 } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
219 if (added)
220 vhost_signal(&vsock->dev, vq);
221
222 out:
223 mutex_unlock(&vq->mutex);
224
225 if (restart_tx)
226 vhost_poll_queue(&tx_vq->poll);
227 }
228
vhost_transport_send_pkt_work(struct vhost_work * work)229 static void vhost_transport_send_pkt_work(struct vhost_work *work)
230 {
231 struct vhost_virtqueue *vq;
232 struct vhost_vsock *vsock;
233
234 vsock = container_of(work, struct vhost_vsock, send_pkt_work);
235 vq = &vsock->vqs[VSOCK_VQ_RX];
236
237 vhost_transport_do_send_pkt(vsock, vq);
238 }
239
240 static int
vhost_transport_send_pkt(struct virtio_vsock_pkt * pkt)241 vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt)
242 {
243 struct vhost_vsock *vsock;
244 int len = pkt->len;
245
246 rcu_read_lock();
247
248 /* Find the vhost_vsock according to guest context id */
249 vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid));
250 if (!vsock) {
251 rcu_read_unlock();
252 virtio_transport_free_pkt(pkt);
253 return -ENODEV;
254 }
255
256 if (pkt->reply)
257 atomic_inc(&vsock->queued_replies);
258
259 spin_lock_bh(&vsock->send_pkt_list_lock);
260 list_add_tail(&pkt->list, &vsock->send_pkt_list);
261 spin_unlock_bh(&vsock->send_pkt_list_lock);
262
263 vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
264
265 rcu_read_unlock();
266 return len;
267 }
268
269 static int
vhost_transport_cancel_pkt(struct vsock_sock * vsk)270 vhost_transport_cancel_pkt(struct vsock_sock *vsk)
271 {
272 struct vhost_vsock *vsock;
273 struct virtio_vsock_pkt *pkt, *n;
274 int cnt = 0;
275 int ret = -ENODEV;
276 LIST_HEAD(freeme);
277
278 rcu_read_lock();
279
280 /* Find the vhost_vsock according to guest context id */
281 vsock = vhost_vsock_get(vsk->remote_addr.svm_cid);
282 if (!vsock)
283 goto out;
284
285 spin_lock_bh(&vsock->send_pkt_list_lock);
286 list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
287 if (pkt->vsk != vsk)
288 continue;
289 list_move(&pkt->list, &freeme);
290 }
291 spin_unlock_bh(&vsock->send_pkt_list_lock);
292
293 list_for_each_entry_safe(pkt, n, &freeme, list) {
294 if (pkt->reply)
295 cnt++;
296 list_del(&pkt->list);
297 virtio_transport_free_pkt(pkt);
298 }
299
300 if (cnt) {
301 struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
302 int new_cnt;
303
304 new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
305 if (new_cnt + cnt >= tx_vq->num && new_cnt < tx_vq->num)
306 vhost_poll_queue(&tx_vq->poll);
307 }
308
309 ret = 0;
310 out:
311 rcu_read_unlock();
312 return ret;
313 }
314
315 static struct virtio_vsock_pkt *
vhost_vsock_alloc_pkt(struct vhost_virtqueue * vq,unsigned int out,unsigned int in)316 vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
317 unsigned int out, unsigned int in)
318 {
319 struct virtio_vsock_pkt *pkt;
320 struct iov_iter iov_iter;
321 size_t nbytes;
322 size_t len;
323
324 if (in != 0) {
325 vq_err(vq, "Expected 0 input buffers, got %u\n", in);
326 return NULL;
327 }
328
329 pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
330 if (!pkt)
331 return NULL;
332
333 len = iov_length(vq->iov, out);
334 iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);
335
336 nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
337 if (nbytes != sizeof(pkt->hdr)) {
338 vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
339 sizeof(pkt->hdr), nbytes);
340 kfree(pkt);
341 return NULL;
342 }
343
344 if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM)
345 pkt->len = le32_to_cpu(pkt->hdr.len);
346
347 /* No payload */
348 if (!pkt->len)
349 return pkt;
350
351 /* The pkt is too big */
352 if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
353 kfree(pkt);
354 return NULL;
355 }
356
357 pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
358 if (!pkt->buf) {
359 kfree(pkt);
360 return NULL;
361 }
362
363 nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
364 if (nbytes != pkt->len) {
365 vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
366 pkt->len, nbytes);
367 virtio_transport_free_pkt(pkt);
368 return NULL;
369 }
370
371 return pkt;
372 }
373
374 /* Is there space left for replies to rx packets? */
vhost_vsock_more_replies(struct vhost_vsock * vsock)375 static bool vhost_vsock_more_replies(struct vhost_vsock *vsock)
376 {
377 struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX];
378 int val;
379
380 smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
381 val = atomic_read(&vsock->queued_replies);
382
383 return val < vq->num;
384 }
385
386 static struct virtio_transport vhost_transport = {
387 .transport = {
388 .get_local_cid = vhost_transport_get_local_cid,
389
390 .init = virtio_transport_do_socket_init,
391 .destruct = virtio_transport_destruct,
392 .release = virtio_transport_release,
393 .connect = virtio_transport_connect,
394 .shutdown = virtio_transport_shutdown,
395 .cancel_pkt = vhost_transport_cancel_pkt,
396
397 .dgram_enqueue = virtio_transport_dgram_enqueue,
398 .dgram_dequeue = virtio_transport_dgram_dequeue,
399 .dgram_bind = virtio_transport_dgram_bind,
400 .dgram_allow = virtio_transport_dgram_allow,
401
402 .stream_enqueue = virtio_transport_stream_enqueue,
403 .stream_dequeue = virtio_transport_stream_dequeue,
404 .stream_has_data = virtio_transport_stream_has_data,
405 .stream_has_space = virtio_transport_stream_has_space,
406 .stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
407 .stream_is_active = virtio_transport_stream_is_active,
408 .stream_allow = virtio_transport_stream_allow,
409
410 .notify_poll_in = virtio_transport_notify_poll_in,
411 .notify_poll_out = virtio_transport_notify_poll_out,
412 .notify_recv_init = virtio_transport_notify_recv_init,
413 .notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
414 .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
415 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
416 .notify_send_init = virtio_transport_notify_send_init,
417 .notify_send_pre_block = virtio_transport_notify_send_pre_block,
418 .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
419 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
420
421 .set_buffer_size = virtio_transport_set_buffer_size,
422 .set_min_buffer_size = virtio_transport_set_min_buffer_size,
423 .set_max_buffer_size = virtio_transport_set_max_buffer_size,
424 .get_buffer_size = virtio_transport_get_buffer_size,
425 .get_min_buffer_size = virtio_transport_get_min_buffer_size,
426 .get_max_buffer_size = virtio_transport_get_max_buffer_size,
427 },
428
429 .send_pkt = vhost_transport_send_pkt,
430 };
431
vhost_vsock_handle_tx_kick(struct vhost_work * work)432 static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
433 {
434 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
435 poll.work);
436 struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
437 dev);
438 struct virtio_vsock_pkt *pkt;
439 int head, pkts = 0, total_len = 0;
440 unsigned int out, in;
441 bool added = false;
442
443 mutex_lock(&vq->mutex);
444
445 if (!vq->private_data)
446 goto out;
447
448 vhost_disable_notify(&vsock->dev, vq);
449 do {
450 u32 len;
451
452 if (!vhost_vsock_more_replies(vsock)) {
453 /* Stop tx until the device processes already
454 * pending replies. Leave tx virtqueue
455 * callbacks disabled.
456 */
457 goto no_more_replies;
458 }
459
460 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
461 &out, &in, NULL, NULL);
462 if (head < 0)
463 break;
464
465 if (head == vq->num) {
466 if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
467 vhost_disable_notify(&vsock->dev, vq);
468 continue;
469 }
470 break;
471 }
472
473 pkt = vhost_vsock_alloc_pkt(vq, out, in);
474 if (!pkt) {
475 vq_err(vq, "Faulted on pkt\n");
476 continue;
477 }
478
479 len = pkt->len;
480
481 /* Deliver to monitoring devices all received packets */
482 virtio_transport_deliver_tap_pkt(pkt);
483
484 /* Only accept correctly addressed packets */
485 if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid &&
486 le64_to_cpu(pkt->hdr.dst_cid) ==
487 vhost_transport_get_local_cid())
488 virtio_transport_recv_pkt(&vhost_transport, pkt);
489 else
490 virtio_transport_free_pkt(pkt);
491
492 len += sizeof(pkt->hdr);
493 vhost_add_used(vq, head, len);
494 total_len += len;
495 added = true;
496 } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
497
498 no_more_replies:
499 if (added)
500 vhost_signal(&vsock->dev, vq);
501
502 out:
503 mutex_unlock(&vq->mutex);
504 }
505
vhost_vsock_handle_rx_kick(struct vhost_work * work)506 static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
507 {
508 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
509 poll.work);
510 struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
511 dev);
512
513 vhost_transport_do_send_pkt(vsock, vq);
514 }
515
vhost_vsock_start(struct vhost_vsock * vsock)516 static int vhost_vsock_start(struct vhost_vsock *vsock)
517 {
518 struct vhost_virtqueue *vq;
519 size_t i;
520 int ret;
521
522 mutex_lock(&vsock->dev.mutex);
523
524 ret = vhost_dev_check_owner(&vsock->dev);
525 if (ret)
526 goto err;
527
528 for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
529 vq = &vsock->vqs[i];
530
531 mutex_lock(&vq->mutex);
532
533 if (!vhost_vq_access_ok(vq)) {
534 ret = -EFAULT;
535 goto err_vq;
536 }
537
538 if (!vq->private_data) {
539 vq->private_data = vsock;
540 ret = vhost_vq_init_access(vq);
541 if (ret)
542 goto err_vq;
543 }
544
545 mutex_unlock(&vq->mutex);
546 }
547
548 /* Some packets may have been queued before the device was started,
549 * let's kick the send worker to send them.
550 */
551 vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
552
553 mutex_unlock(&vsock->dev.mutex);
554 return 0;
555
556 err_vq:
557 vq->private_data = NULL;
558 mutex_unlock(&vq->mutex);
559
560 for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
561 vq = &vsock->vqs[i];
562
563 mutex_lock(&vq->mutex);
564 vq->private_data = NULL;
565 mutex_unlock(&vq->mutex);
566 }
567 err:
568 mutex_unlock(&vsock->dev.mutex);
569 return ret;
570 }
571
vhost_vsock_stop(struct vhost_vsock * vsock)572 static int vhost_vsock_stop(struct vhost_vsock *vsock)
573 {
574 size_t i;
575 int ret;
576
577 mutex_lock(&vsock->dev.mutex);
578
579 ret = vhost_dev_check_owner(&vsock->dev);
580 if (ret)
581 goto err;
582
583 for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
584 struct vhost_virtqueue *vq = &vsock->vqs[i];
585
586 mutex_lock(&vq->mutex);
587 vq->private_data = NULL;
588 mutex_unlock(&vq->mutex);
589 }
590
591 err:
592 mutex_unlock(&vsock->dev.mutex);
593 return ret;
594 }
595
vhost_vsock_free(struct vhost_vsock * vsock)596 static void vhost_vsock_free(struct vhost_vsock *vsock)
597 {
598 kvfree(vsock);
599 }
600
vhost_vsock_dev_open(struct inode * inode,struct file * file)601 static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
602 {
603 struct vhost_virtqueue **vqs;
604 struct vhost_vsock *vsock;
605 int ret;
606
607 /* This struct is large and allocation could fail, fall back to vmalloc
608 * if there is no other way.
609 */
610 vsock = kvmalloc(sizeof(*vsock), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
611 if (!vsock)
612 return -ENOMEM;
613
614 vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
615 if (!vqs) {
616 ret = -ENOMEM;
617 goto out;
618 }
619
620 vsock->guest_cid = 0; /* no CID assigned yet */
621
622 atomic_set(&vsock->queued_replies, 0);
623
624 vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
625 vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
626 vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
627 vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
628
629 vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
630 UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT,
631 VHOST_VSOCK_WEIGHT);
632
633 file->private_data = vsock;
634 spin_lock_init(&vsock->send_pkt_list_lock);
635 INIT_LIST_HEAD(&vsock->send_pkt_list);
636 vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
637 return 0;
638
639 out:
640 vhost_vsock_free(vsock);
641 return ret;
642 }
643
vhost_vsock_flush(struct vhost_vsock * vsock)644 static void vhost_vsock_flush(struct vhost_vsock *vsock)
645 {
646 int i;
647
648 for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++)
649 if (vsock->vqs[i].handle_kick)
650 vhost_poll_flush(&vsock->vqs[i].poll);
651 vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
652 }
653
vhost_vsock_reset_orphans(struct sock * sk)654 static void vhost_vsock_reset_orphans(struct sock *sk)
655 {
656 struct vsock_sock *vsk = vsock_sk(sk);
657
658 /* vmci_transport.c doesn't take sk_lock here either. At least we're
659 * under vsock_table_lock so the sock cannot disappear while we're
660 * executing.
661 */
662
663 /* If the peer is still valid, no need to reset connection */
664 if (vhost_vsock_get(vsk->remote_addr.svm_cid))
665 return;
666
667 /* If the close timeout is pending, let it expire. This avoids races
668 * with the timeout callback.
669 */
670 if (vsk->close_work_scheduled)
671 return;
672
673 sock_set_flag(sk, SOCK_DONE);
674 vsk->peer_shutdown = SHUTDOWN_MASK;
675 sk->sk_state = SS_UNCONNECTED;
676 sk->sk_err = ECONNRESET;
677 sk->sk_error_report(sk);
678 }
679
vhost_vsock_dev_release(struct inode * inode,struct file * file)680 static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
681 {
682 struct vhost_vsock *vsock = file->private_data;
683
684 spin_lock_bh(&vhost_vsock_lock);
685 if (vsock->guest_cid)
686 hash_del_rcu(&vsock->hash);
687 spin_unlock_bh(&vhost_vsock_lock);
688
689 /* Wait for other CPUs to finish using vsock */
690 synchronize_rcu();
691
692 /* Iterating over all connections for all CIDs to find orphans is
693 * inefficient. Room for improvement here. */
694 vsock_for_each_connected_socket(vhost_vsock_reset_orphans);
695
696 vhost_vsock_stop(vsock);
697 vhost_vsock_flush(vsock);
698 vhost_dev_stop(&vsock->dev);
699
700 spin_lock_bh(&vsock->send_pkt_list_lock);
701 while (!list_empty(&vsock->send_pkt_list)) {
702 struct virtio_vsock_pkt *pkt;
703
704 pkt = list_first_entry(&vsock->send_pkt_list,
705 struct virtio_vsock_pkt, list);
706 list_del_init(&pkt->list);
707 virtio_transport_free_pkt(pkt);
708 }
709 spin_unlock_bh(&vsock->send_pkt_list_lock);
710
711 vhost_dev_cleanup(&vsock->dev);
712 kfree(vsock->dev.vqs);
713 vhost_vsock_free(vsock);
714 return 0;
715 }
716
vhost_vsock_set_cid(struct vhost_vsock * vsock,u64 guest_cid)717 static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
718 {
719 struct vhost_vsock *other;
720
721 /* Refuse reserved CIDs */
722 if (guest_cid <= VMADDR_CID_HOST ||
723 guest_cid == U32_MAX)
724 return -EINVAL;
725
726 /* 64-bit CIDs are not yet supported */
727 if (guest_cid > U32_MAX)
728 return -EINVAL;
729
730 /* Refuse if CID is already in use */
731 spin_lock_bh(&vhost_vsock_lock);
732 other = vhost_vsock_get(guest_cid);
733 if (other && other != vsock) {
734 spin_unlock_bh(&vhost_vsock_lock);
735 return -EADDRINUSE;
736 }
737
738 if (vsock->guest_cid)
739 hash_del_rcu(&vsock->hash);
740
741 vsock->guest_cid = guest_cid;
742 hash_add_rcu(vhost_vsock_hash, &vsock->hash, vsock->guest_cid);
743 spin_unlock_bh(&vhost_vsock_lock);
744
745 return 0;
746 }
747
vhost_vsock_set_features(struct vhost_vsock * vsock,u64 features)748 static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
749 {
750 struct vhost_virtqueue *vq;
751 int i;
752
753 if (features & ~VHOST_VSOCK_FEATURES)
754 return -EOPNOTSUPP;
755
756 mutex_lock(&vsock->dev.mutex);
757 if ((features & (1 << VHOST_F_LOG_ALL)) &&
758 !vhost_log_access_ok(&vsock->dev)) {
759 mutex_unlock(&vsock->dev.mutex);
760 return -EFAULT;
761 }
762
763 for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
764 vq = &vsock->vqs[i];
765 mutex_lock(&vq->mutex);
766 vq->acked_features = features;
767 mutex_unlock(&vq->mutex);
768 }
769 mutex_unlock(&vsock->dev.mutex);
770 return 0;
771 }
772
vhost_vsock_dev_ioctl(struct file * f,unsigned int ioctl,unsigned long arg)773 static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
774 unsigned long arg)
775 {
776 struct vhost_vsock *vsock = f->private_data;
777 void __user *argp = (void __user *)arg;
778 u64 guest_cid;
779 u64 features;
780 int start;
781 int r;
782
783 switch (ioctl) {
784 case VHOST_VSOCK_SET_GUEST_CID:
785 if (copy_from_user(&guest_cid, argp, sizeof(guest_cid)))
786 return -EFAULT;
787 return vhost_vsock_set_cid(vsock, guest_cid);
788 case VHOST_VSOCK_SET_RUNNING:
789 if (copy_from_user(&start, argp, sizeof(start)))
790 return -EFAULT;
791 if (start)
792 return vhost_vsock_start(vsock);
793 else
794 return vhost_vsock_stop(vsock);
795 case VHOST_GET_FEATURES:
796 features = VHOST_VSOCK_FEATURES;
797 if (copy_to_user(argp, &features, sizeof(features)))
798 return -EFAULT;
799 return 0;
800 case VHOST_SET_FEATURES:
801 if (copy_from_user(&features, argp, sizeof(features)))
802 return -EFAULT;
803 return vhost_vsock_set_features(vsock, features);
804 default:
805 mutex_lock(&vsock->dev.mutex);
806 r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
807 if (r == -ENOIOCTLCMD)
808 r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
809 else
810 vhost_vsock_flush(vsock);
811 mutex_unlock(&vsock->dev.mutex);
812 return r;
813 }
814 }
815
816 #ifdef CONFIG_COMPAT
vhost_vsock_dev_compat_ioctl(struct file * f,unsigned int ioctl,unsigned long arg)817 static long vhost_vsock_dev_compat_ioctl(struct file *f, unsigned int ioctl,
818 unsigned long arg)
819 {
820 return vhost_vsock_dev_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
821 }
822 #endif
823
824 static const struct file_operations vhost_vsock_fops = {
825 .owner = THIS_MODULE,
826 .open = vhost_vsock_dev_open,
827 .release = vhost_vsock_dev_release,
828 .llseek = noop_llseek,
829 .unlocked_ioctl = vhost_vsock_dev_ioctl,
830 #ifdef CONFIG_COMPAT
831 .compat_ioctl = vhost_vsock_dev_compat_ioctl,
832 #endif
833 };
834
835 static struct miscdevice vhost_vsock_misc = {
836 .minor = VHOST_VSOCK_MINOR,
837 .name = "vhost-vsock",
838 .fops = &vhost_vsock_fops,
839 };
840
vhost_vsock_init(void)841 static int __init vhost_vsock_init(void)
842 {
843 int ret;
844
845 ret = vsock_core_init(&vhost_transport.transport);
846 if (ret < 0)
847 return ret;
848 return misc_register(&vhost_vsock_misc);
849 };
850
vhost_vsock_exit(void)851 static void __exit vhost_vsock_exit(void)
852 {
853 misc_deregister(&vhost_vsock_misc);
854 vsock_core_exit();
855 };
856
857 module_init(vhost_vsock_init);
858 module_exit(vhost_vsock_exit);
859 MODULE_LICENSE("GPL v2");
860 MODULE_AUTHOR("Asias He");
861 MODULE_DESCRIPTION("vhost transport for vsock ");
862 MODULE_ALIAS_MISCDEV(VHOST_VSOCK_MINOR);
863 MODULE_ALIAS("devname:vhost-vsock");
864