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staging: brcm80211: bugfix for stack dump on firmware load problems
[wandboard.git] / drivers / vhost / net.c
blobf616cefc95ba74e13bf159c817c49a6fe928fe10
1 /* Copyright (C) 2009 Red Hat, Inc.
2 * Author: Michael S. Tsirkin <mst@redhat.com>
3 *
4 * This work is licensed under the terms of the GNU GPL, version 2.
5 *
6 * virtio-net server in host kernel.
7 */
8
9 #include <linux/compat.h>
10 #include <linux/eventfd.h>
11 #include <linux/vhost.h>
12 #include <linux/virtio_net.h>
13 #include <linux/miscdevice.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/workqueue.h>
17 #include <linux/rcupdate.h>
18 #include <linux/file.h>
19 #include <linux/slab.h>
20
21 #include <linux/net.h>
22 #include <linux/if_packet.h>
23 #include <linux/if_arp.h>
24 #include <linux/if_tun.h>
25 #include <linux/if_macvlan.h>
26
27 #include <net/sock.h>
28
29 #include "vhost.h"
30
31 /* Max number of bytes transferred before requeueing the job.
32 * Using this limit prevents one virtqueue from starving others. */
33 #define VHOST_NET_WEIGHT 0x80000
34
35 enum {
36 VHOST_NET_VQ_RX = 0,
37 VHOST_NET_VQ_TX = 1,
38 VHOST_NET_VQ_MAX = 2,
39 };
40
41 enum vhost_net_poll_state {
42 VHOST_NET_POLL_DISABLED = 0,
43 VHOST_NET_POLL_STARTED = 1,
44 VHOST_NET_POLL_STOPPED = 2,
45 };
46
47 struct vhost_net {
48 struct vhost_dev dev;
49 struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX];
50 struct vhost_poll poll[VHOST_NET_VQ_MAX];
51 /* Tells us whether we are polling a socket for TX.
52 * We only do this when socket buffer fills up.
53 * Protected by tx vq lock. */
54 enum vhost_net_poll_state tx_poll_state;
55 };
56
57 /* Pop first len bytes from iovec. Return number of segments used. */
58 static int move_iovec_hdr(struct iovec *from, struct iovec *to,
59 size_t len, int iov_count)
60 {
61 int seg = 0;
62 size_t size;
63 while (len && seg < iov_count) {
64 size = min(from->iov_len, len);
65 to->iov_base = from->iov_base;
66 to->iov_len = size;
67 from->iov_len -= size;
68 from->iov_base += size;
69 len -= size;
70 ++from;
71 ++to;
72 ++seg;
73 }
74 return seg;
75 }
76 /* Copy iovec entries for len bytes from iovec. */
77 static void copy_iovec_hdr(const struct iovec *from, struct iovec *to,
78 size_t len, int iovcount)
79 {
80 int seg = 0;
81 size_t size;
82 while (len && seg < iovcount) {
83 size = min(from->iov_len, len);
84 to->iov_base = from->iov_base;
85 to->iov_len = size;
86 len -= size;
87 ++from;
88 ++to;
89 ++seg;
90 }
91 }
92
93 /* Caller must have TX VQ lock */
94 static void tx_poll_stop(struct vhost_net *net)
95 {
96 if (likely(net->tx_poll_state != VHOST_NET_POLL_STARTED))
97 return;
98 vhost_poll_stop(net->poll + VHOST_NET_VQ_TX);
99 net->tx_poll_state = VHOST_NET_POLL_STOPPED;
100 }
101
102 /* Caller must have TX VQ lock */
103 static void tx_poll_start(struct vhost_net *net, struct socket *sock)
104 {
105 if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED))
106 return;
107 vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file);
108 net->tx_poll_state = VHOST_NET_POLL_STARTED;
109 }
110
111 /* Expects to be always run from workqueue - which acts as
112 * read-size critical section for our kind of RCU. */
113 static void handle_tx(struct vhost_net *net)
114 {
115 struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
116 unsigned out, in, s;
117 int head;
118 struct msghdr msg = {
119 .msg_name = NULL,
120 .msg_namelen = 0,
121 .msg_control = NULL,
122 .msg_controllen = 0,
123 .msg_iov = vq->iov,
124 .msg_flags = MSG_DONTWAIT,
125 };
126 size_t len, total_len = 0;
127 int err, wmem;
128 size_t hdr_size;
129 struct socket *sock;
130
131 /* TODO: check that we are running from vhost_worker? */
132 sock = rcu_dereference_check(vq->private_data, 1);
133 if (!sock)
134 return;
135
136 wmem = atomic_read(&sock->sk->sk_wmem_alloc);
137 if (wmem >= sock->sk->sk_sndbuf) {
138 mutex_lock(&vq->mutex);
139 tx_poll_start(net, sock);
140 mutex_unlock(&vq->mutex);
141 return;
142 }
143
144 mutex_lock(&vq->mutex);
145 vhost_disable_notify(vq);
146
147 if (wmem < sock->sk->sk_sndbuf / 2)
148 tx_poll_stop(net);
149 hdr_size = vq->vhost_hlen;
150
151 for (;;) {
152 head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
153 ARRAY_SIZE(vq->iov),
154 &out, &in,
155 NULL, NULL);
156 /* On error, stop handling until the next kick. */
157 if (unlikely(head < 0))
158 break;
159 /* Nothing new? Wait for eventfd to tell us they refilled. */
160 if (head == vq->num) {
161 wmem = atomic_read(&sock->sk->sk_wmem_alloc);
162 if (wmem >= sock->sk->sk_sndbuf * 3 / 4) {
163 tx_poll_start(net, sock);
164 set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
165 break;
166 }
167 if (unlikely(vhost_enable_notify(vq))) {
168 vhost_disable_notify(vq);
169 continue;
170 }
171 break;
172 }
173 if (in) {
174 vq_err(vq, "Unexpected descriptor format for TX: "
175 "out %d, int %d\n", out, in);
176 break;
177 }
178 /* Skip header. TODO: support TSO. */
179 s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out);
180 msg.msg_iovlen = out;
181 len = iov_length(vq->iov, out);
182 /* Sanity check */
183 if (!len) {
184 vq_err(vq, "Unexpected header len for TX: "
185 "%zd expected %zd\n",
186 iov_length(vq->hdr, s), hdr_size);
187 break;
188 }
189 /* TODO: Check specific error and bomb out unless ENOBUFS? */
190 err = sock->ops->sendmsg(NULL, sock, &msg, len);
191 if (unlikely(err < 0)) {
192 vhost_discard_vq_desc(vq, 1);
193 tx_poll_start(net, sock);
194 break;
195 }
196 if (err != len)
197 pr_debug("Truncated TX packet: "
198 " len %d != %zd\n", err, len);
199 vhost_add_used_and_signal(&net->dev, vq, head, 0);
200 total_len += len;
201 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
202 vhost_poll_queue(&vq->poll);
203 break;
204 }
205 }
206
207 mutex_unlock(&vq->mutex);
208 }
209
210 static int peek_head_len(struct sock *sk)
211 {
212 struct sk_buff *head;
213 int len = 0;
214
215 lock_sock(sk);
216 head = skb_peek(&sk->sk_receive_queue);
217 if (head)
218 len = head->len;
219 release_sock(sk);
220 return len;
221 }
222
223 /* This is a multi-buffer version of vhost_get_desc, that works if
224 * vq has read descriptors only.
225 * @vq - the relevant virtqueue
226 * @datalen - data length we'll be reading
227 * @iovcount - returned count of io vectors we fill
228 * @log - vhost log
229 * @log_num - log offset
230 * returns number of buffer heads allocated, negative on error
231 */
232 static int get_rx_bufs(struct vhost_virtqueue *vq,
233 struct vring_used_elem *heads,
234 int datalen,
235 unsigned *iovcount,
236 struct vhost_log *log,
237 unsigned *log_num)
238 {
239 unsigned int out, in;
240 int seg = 0;
241 int headcount = 0;
242 unsigned d;
243 int r, nlogs = 0;
244
245 while (datalen > 0) {
246 if (unlikely(seg >= UIO_MAXIOV)) {
247 r = -ENOBUFS;
248 goto err;
249 }
250 d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
251 ARRAY_SIZE(vq->iov) - seg, &out,
252 &in, log, log_num);
253 if (d == vq->num) {
254 r = 0;
255 goto err;
256 }
257 if (unlikely(out || in <= 0)) {
258 vq_err(vq, "unexpected descriptor format for RX: "
259 "out %d, in %d\n", out, in);
260 r = -EINVAL;
261 goto err;
262 }
263 if (unlikely(log)) {
264 nlogs += *log_num;
265 log += *log_num;
266 }
267 heads[headcount].id = d;
268 heads[headcount].len = iov_length(vq->iov + seg, in);
269 datalen -= heads[headcount].len;
270 ++headcount;
271 seg += in;
272 }
273 heads[headcount - 1].len += datalen;
274 *iovcount = seg;
275 if (unlikely(log))
276 *log_num = nlogs;
277 return headcount;
278 err:
279 vhost_discard_vq_desc(vq, headcount);
280 return r;
281 }
282
283 /* Expects to be always run from workqueue - which acts as
284 * read-size critical section for our kind of RCU. */
285 static void handle_rx_big(struct vhost_net *net)
286 {
287 struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
288 unsigned out, in, log, s;
289 int head;
290 struct vhost_log *vq_log;
291 struct msghdr msg = {
292 .msg_name = NULL,
293 .msg_namelen = 0,
294 .msg_control = NULL, /* FIXME: get and handle RX aux data. */
295 .msg_controllen = 0,
296 .msg_iov = vq->iov,
297 .msg_flags = MSG_DONTWAIT,
298 };
299
300 struct virtio_net_hdr hdr = {
301 .flags = 0,
302 .gso_type = VIRTIO_NET_HDR_GSO_NONE
303 };
304
305 size_t len, total_len = 0;
306 int err;
307 size_t hdr_size;
308 /* TODO: check that we are running from vhost_worker? */
309 struct socket *sock = rcu_dereference_check(vq->private_data, 1);
310 if (!sock || skb_queue_empty(&sock->sk->sk_receive_queue))
311 return;
312
313 mutex_lock(&vq->mutex);
314 vhost_disable_notify(vq);
315 hdr_size = vq->vhost_hlen;
316
317 vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
318 vq->log : NULL;
319
320 for (;;) {
321 head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
322 ARRAY_SIZE(vq->iov),
323 &out, &in,
324 vq_log, &log);
325 /* On error, stop handling until the next kick. */
326 if (unlikely(head < 0))
327 break;
328 /* OK, now we need to know about added descriptors. */
329 if (head == vq->num) {
330 if (unlikely(vhost_enable_notify(vq))) {
331 /* They have slipped one in as we were
332 * doing that: check again. */
333 vhost_disable_notify(vq);
334 continue;
335 }
336 /* Nothing new? Wait for eventfd to tell us
337 * they refilled. */
338 break;
339 }
340 /* We don't need to be notified again. */
341 if (out) {
342 vq_err(vq, "Unexpected descriptor format for RX: "
343 "out %d, int %d\n",
344 out, in);
345 break;
346 }
347 /* Skip header. TODO: support TSO/mergeable rx buffers. */
348 s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, in);
349 msg.msg_iovlen = in;
350 len = iov_length(vq->iov, in);
351 /* Sanity check */
352 if (!len) {
353 vq_err(vq, "Unexpected header len for RX: "
354 "%zd expected %zd\n",
355 iov_length(vq->hdr, s), hdr_size);
356 break;
357 }
358 err = sock->ops->recvmsg(NULL, sock, &msg,
359 len, MSG_DONTWAIT | MSG_TRUNC);
360 /* TODO: Check specific error and bomb out unless EAGAIN? */
361 if (err < 0) {
362 vhost_discard_vq_desc(vq, 1);
363 break;
364 }
365 /* TODO: Should check and handle checksum. */
366 if (err > len) {
367 pr_debug("Discarded truncated rx packet: "
368 " len %d > %zd\n", err, len);
369 vhost_discard_vq_desc(vq, 1);
370 continue;
371 }
372 len = err;
373 err = memcpy_toiovec(vq->hdr, (unsigned char *)&hdr, hdr_size);
374 if (err) {
375 vq_err(vq, "Unable to write vnet_hdr at addr %p: %d\n",
376 vq->iov->iov_base, err);
377 break;
378 }
379 len += hdr_size;
380 vhost_add_used_and_signal(&net->dev, vq, head, len);
381 if (unlikely(vq_log))
382 vhost_log_write(vq, vq_log, log, len);
383 total_len += len;
384 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
385 vhost_poll_queue(&vq->poll);
386 break;
387 }
388 }
389
390 mutex_unlock(&vq->mutex);
391 }
392
393 /* Expects to be always run from workqueue - which acts as
394 * read-size critical section for our kind of RCU. */
395 static void handle_rx_mergeable(struct vhost_net *net)
396 {
397 struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
398 unsigned uninitialized_var(in), log;
399 struct vhost_log *vq_log;
400 struct msghdr msg = {
401 .msg_name = NULL,
402 .msg_namelen = 0,
403 .msg_control = NULL, /* FIXME: get and handle RX aux data. */
404 .msg_controllen = 0,
405 .msg_iov = vq->iov,
406 .msg_flags = MSG_DONTWAIT,
407 };
408
409 struct virtio_net_hdr_mrg_rxbuf hdr = {
410 .hdr.flags = 0,
411 .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
412 };
413
414 size_t total_len = 0;
415 int err, headcount;
416 size_t vhost_hlen, sock_hlen;
417 size_t vhost_len, sock_len;
418 /* TODO: check that we are running from vhost_worker? */
419 struct socket *sock = rcu_dereference_check(vq->private_data, 1);
420 if (!sock || skb_queue_empty(&sock->sk->sk_receive_queue))
421 return;
422
423 mutex_lock(&vq->mutex);
424 vhost_disable_notify(vq);
425 vhost_hlen = vq->vhost_hlen;
426 sock_hlen = vq->sock_hlen;
427
428 vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
429 vq->log : NULL;
430
431 while ((sock_len = peek_head_len(sock->sk))) {
432 sock_len += sock_hlen;
433 vhost_len = sock_len + vhost_hlen;
434 headcount = get_rx_bufs(vq, vq->heads, vhost_len,
435 &in, vq_log, &log);
436 /* On error, stop handling until the next kick. */
437 if (unlikely(headcount < 0))
438 break;
439 /* OK, now we need to know about added descriptors. */
440 if (!headcount) {
441 if (unlikely(vhost_enable_notify(vq))) {
442 /* They have slipped one in as we were
443 * doing that: check again. */
444 vhost_disable_notify(vq);
445 continue;
446 }
447 /* Nothing new? Wait for eventfd to tell us
448 * they refilled. */
449 break;
450 }
451 /* We don't need to be notified again. */
452 if (unlikely((vhost_hlen)))
453 /* Skip header. TODO: support TSO. */
454 move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in);
455 else
456 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
457 * needed because recvmsg can modify msg_iov. */
458 copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in);
459 msg.msg_iovlen = in;
460 err = sock->ops->recvmsg(NULL, sock, &msg,
461 sock_len, MSG_DONTWAIT | MSG_TRUNC);
462 /* Userspace might have consumed the packet meanwhile:
463 * it's not supposed to do this usually, but might be hard
464 * to prevent. Discard data we got (if any) and keep going. */
465 if (unlikely(err != sock_len)) {
466 pr_debug("Discarded rx packet: "
467 " len %d, expected %zd\n", err, sock_len);
468 vhost_discard_vq_desc(vq, headcount);
469 continue;
470 }
471 if (unlikely(vhost_hlen) &&
472 memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0,
473 vhost_hlen)) {
474 vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
475 vq->iov->iov_base);
476 break;
477 }
478 /* TODO: Should check and handle checksum. */
479 if (vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF) &&
480 memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount,
481 offsetof(typeof(hdr), num_buffers),
482 sizeof hdr.num_buffers)) {
483 vq_err(vq, "Failed num_buffers write");
484 vhost_discard_vq_desc(vq, headcount);
485 break;
486 }
487 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
488 headcount);
489 if (unlikely(vq_log))
490 vhost_log_write(vq, vq_log, log, vhost_len);
491 total_len += vhost_len;
492 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
493 vhost_poll_queue(&vq->poll);
494 break;
495 }
496 }
497
498 mutex_unlock(&vq->mutex);
499 }
500
501 static void handle_rx(struct vhost_net *net)
502 {
503 if (vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF))
504 handle_rx_mergeable(net);
505 else
506 handle_rx_big(net);
507 }
508
509 static void handle_tx_kick(struct vhost_work *work)
510 {
511 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
512 poll.work);
513 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
514
515 handle_tx(net);
516 }
517
518 static void handle_rx_kick(struct vhost_work *work)
519 {
520 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
521 poll.work);
522 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
523
524 handle_rx(net);
525 }
526
527 static void handle_tx_net(struct vhost_work *work)
528 {
529 struct vhost_net *net = container_of(work, struct vhost_net,
530 poll[VHOST_NET_VQ_TX].work);
531 handle_tx(net);
532 }
533
534 static void handle_rx_net(struct vhost_work *work)
535 {
536 struct vhost_net *net = container_of(work, struct vhost_net,
537 poll[VHOST_NET_VQ_RX].work);
538 handle_rx(net);
539 }
540
541 static int vhost_net_open(struct inode *inode, struct file *f)
542 {
543 struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
544 struct vhost_dev *dev;
545 int r;
546
547 if (!n)
548 return -ENOMEM;
549
550 dev = &n->dev;
551 n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
552 n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
553 r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
554 if (r < 0) {
555 kfree(n);
556 return r;
557 }
558
559 vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
560 vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
561 n->tx_poll_state = VHOST_NET_POLL_DISABLED;
562
563 f->private_data = n;
564
565 return 0;
566 }
567
568 static void vhost_net_disable_vq(struct vhost_net *n,
569 struct vhost_virtqueue *vq)
570 {
571 if (!vq->private_data)
572 return;
573 if (vq == n->vqs + VHOST_NET_VQ_TX) {
574 tx_poll_stop(n);
575 n->tx_poll_state = VHOST_NET_POLL_DISABLED;
576 } else
577 vhost_poll_stop(n->poll + VHOST_NET_VQ_RX);
578 }
579
580 static void vhost_net_enable_vq(struct vhost_net *n,
581 struct vhost_virtqueue *vq)
582 {
583 struct socket *sock;
584
585 sock = rcu_dereference_protected(vq->private_data,
586 lockdep_is_held(&vq->mutex));
587 if (!sock)
588 return;
589 if (vq == n->vqs + VHOST_NET_VQ_TX) {
590 n->tx_poll_state = VHOST_NET_POLL_STOPPED;
591 tx_poll_start(n, sock);
592 } else
593 vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file);
594 }
595
596 static struct socket *vhost_net_stop_vq(struct vhost_net *n,
597 struct vhost_virtqueue *vq)
598 {
599 struct socket *sock;
600
601 mutex_lock(&vq->mutex);
602 sock = rcu_dereference_protected(vq->private_data,
603 lockdep_is_held(&vq->mutex));
604 vhost_net_disable_vq(n, vq);
605 rcu_assign_pointer(vq->private_data, NULL);
606 mutex_unlock(&vq->mutex);
607 return sock;
608 }
609
610 static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
611 struct socket **rx_sock)
612 {
613 *tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX);
614 *rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX);
615 }
616
617 static void vhost_net_flush_vq(struct vhost_net *n, int index)
618 {
619 vhost_poll_flush(n->poll + index);
620 vhost_poll_flush(&n->dev.vqs[index].poll);
621 }
622
623 static void vhost_net_flush(struct vhost_net *n)
624 {
625 vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
626 vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
627 }
628
629 static int vhost_net_release(struct inode *inode, struct file *f)
630 {
631 struct vhost_net *n = f->private_data;
632 struct socket *tx_sock;
633 struct socket *rx_sock;
634
635 vhost_net_stop(n, &tx_sock, &rx_sock);
636 vhost_net_flush(n);
637 vhost_dev_cleanup(&n->dev);
638 if (tx_sock)
639 fput(tx_sock->file);
640 if (rx_sock)
641 fput(rx_sock->file);
642 /* We do an extra flush before freeing memory,
643 * since jobs can re-queue themselves. */
644 vhost_net_flush(n);
645 kfree(n);
646 return 0;
647 }
648
649 static struct socket *get_raw_socket(int fd)
650 {
651 struct {
652 struct sockaddr_ll sa;
653 char buf[MAX_ADDR_LEN];
654 } uaddr;
655 int uaddr_len = sizeof uaddr, r;
656 struct socket *sock = sockfd_lookup(fd, &r);
657 if (!sock)
658 return ERR_PTR(-ENOTSOCK);
659
660 /* Parameter checking */
661 if (sock->sk->sk_type != SOCK_RAW) {
662 r = -ESOCKTNOSUPPORT;
663 goto err;
664 }
665
666 r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
667 &uaddr_len, 0);
668 if (r)
669 goto err;
670
671 if (uaddr.sa.sll_family != AF_PACKET) {
672 r = -EPFNOSUPPORT;
673 goto err;
674 }
675 return sock;
676 err:
677 fput(sock->file);
678 return ERR_PTR(r);
679 }
680
681 static struct socket *get_tap_socket(int fd)
682 {
683 struct file *file = fget(fd);
684 struct socket *sock;
685 if (!file)
686 return ERR_PTR(-EBADF);
687 sock = tun_get_socket(file);
688 if (!IS_ERR(sock))
689 return sock;
690 sock = macvtap_get_socket(file);
691 if (IS_ERR(sock))
692 fput(file);
693 return sock;
694 }
695
696 static struct socket *get_socket(int fd)
697 {
698 struct socket *sock;
699 /* special case to disable backend */
700 if (fd == -1)
701 return NULL;
702 sock = get_raw_socket(fd);
703 if (!IS_ERR(sock))
704 return sock;
705 sock = get_tap_socket(fd);
706 if (!IS_ERR(sock))
707 return sock;
708 return ERR_PTR(-ENOTSOCK);
709 }
710
711 static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
712 {
713 struct socket *sock, *oldsock;
714 struct vhost_virtqueue *vq;
715 int r;
716
717 mutex_lock(&n->dev.mutex);
718 r = vhost_dev_check_owner(&n->dev);
719 if (r)
720 goto err;
721
722 if (index >= VHOST_NET_VQ_MAX) {
723 r = -ENOBUFS;
724 goto err;
725 }
726 vq = n->vqs + index;
727 mutex_lock(&vq->mutex);
728
729 /* Verify that ring has been setup correctly. */
730 if (!vhost_vq_access_ok(vq)) {
731 r = -EFAULT;
732 goto err_vq;
733 }
734 sock = get_socket(fd);
735 if (IS_ERR(sock)) {
736 r = PTR_ERR(sock);
737 goto err_vq;
738 }
739
740 /* start polling new socket */
741 oldsock = rcu_dereference_protected(vq->private_data,
742 lockdep_is_held(&vq->mutex));
743 if (sock != oldsock) {
744 vhost_net_disable_vq(n, vq);
745 rcu_assign_pointer(vq->private_data, sock);
746 vhost_net_enable_vq(n, vq);
747 }
748
749 mutex_unlock(&vq->mutex);
750
751 if (oldsock) {
752 vhost_net_flush_vq(n, index);
753 fput(oldsock->file);
754 }
755
756 mutex_unlock(&n->dev.mutex);
757 return 0;
758
759 err_vq:
760 mutex_unlock(&vq->mutex);
761 err:
762 mutex_unlock(&n->dev.mutex);
763 return r;
764 }
765
766 static long vhost_net_reset_owner(struct vhost_net *n)
767 {
768 struct socket *tx_sock = NULL;
769 struct socket *rx_sock = NULL;
770 long err;
771 mutex_lock(&n->dev.mutex);
772 err = vhost_dev_check_owner(&n->dev);
773 if (err)
774 goto done;
775 vhost_net_stop(n, &tx_sock, &rx_sock);
776 vhost_net_flush(n);
777 err = vhost_dev_reset_owner(&n->dev);
778 done:
779 mutex_unlock(&n->dev.mutex);
780 if (tx_sock)
781 fput(tx_sock->file);
782 if (rx_sock)
783 fput(rx_sock->file);
784 return err;
785 }
786
787 static int vhost_net_set_features(struct vhost_net *n, u64 features)
788 {
789 size_t vhost_hlen, sock_hlen, hdr_len;
790 int i;
791
792 hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
793 sizeof(struct virtio_net_hdr_mrg_rxbuf) :
794 sizeof(struct virtio_net_hdr);
795 if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
796 /* vhost provides vnet_hdr */
797 vhost_hlen = hdr_len;
798 sock_hlen = 0;
799 } else {
800 /* socket provides vnet_hdr */
801 vhost_hlen = 0;
802 sock_hlen = hdr_len;
803 }
804 mutex_lock(&n->dev.mutex);
805 if ((features & (1 << VHOST_F_LOG_ALL)) &&
806 !vhost_log_access_ok(&n->dev)) {
807 mutex_unlock(&n->dev.mutex);
808 return -EFAULT;
809 }
810 n->dev.acked_features = features;
811 smp_wmb();
812 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
813 mutex_lock(&n->vqs[i].mutex);
814 n->vqs[i].vhost_hlen = vhost_hlen;
815 n->vqs[i].sock_hlen = sock_hlen;
816 mutex_unlock(&n->vqs[i].mutex);
817 }
818 vhost_net_flush(n);
819 mutex_unlock(&n->dev.mutex);
820 return 0;
821 }
822
823 static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
824 unsigned long arg)
825 {
826 struct vhost_net *n = f->private_data;
827 void __user *argp = (void __user *)arg;
828 u64 __user *featurep = argp;
829 struct vhost_vring_file backend;
830 u64 features;
831 int r;
832 switch (ioctl) {
833 case VHOST_NET_SET_BACKEND:
834 if (copy_from_user(&backend, argp, sizeof backend))
835 return -EFAULT;
836 return vhost_net_set_backend(n, backend.index, backend.fd);
837 case VHOST_GET_FEATURES:
838 features = VHOST_FEATURES;
839 if (copy_to_user(featurep, &features, sizeof features))
840 return -EFAULT;
841 return 0;
842 case VHOST_SET_FEATURES:
843 if (copy_from_user(&features, featurep, sizeof features))
844 return -EFAULT;
845 if (features & ~VHOST_FEATURES)
846 return -EOPNOTSUPP;
847 return vhost_net_set_features(n, features);
848 case VHOST_RESET_OWNER:
849 return vhost_net_reset_owner(n);
850 default:
851 mutex_lock(&n->dev.mutex);
852 r = vhost_dev_ioctl(&n->dev, ioctl, arg);
853 vhost_net_flush(n);
854 mutex_unlock(&n->dev.mutex);
855 return r;
856 }
857 }
858
859 #ifdef CONFIG_COMPAT
860 static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
861 unsigned long arg)
862 {
863 return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
864 }
865 #endif
866
867 static const struct file_operations vhost_net_fops = {
868 .owner = THIS_MODULE,
869 .release = vhost_net_release,
870 .unlocked_ioctl = vhost_net_ioctl,
871 #ifdef CONFIG_COMPAT
872 .compat_ioctl = vhost_net_compat_ioctl,
873 #endif
874 .open = vhost_net_open,
875 .llseek = noop_llseek,
876 };
877
878 static struct miscdevice vhost_net_misc = {
879 MISC_DYNAMIC_MINOR,
880 "vhost-net",
881 &vhost_net_fops,
882 };
883
884 static int vhost_net_init(void)
885 {
886 return misc_register(&vhost_net_misc);
887 }
888 module_init(vhost_net_init);
889
890 static void vhost_net_exit(void)
891 {
892 misc_deregister(&vhost_net_misc);
893 }
894 module_exit(vhost_net_exit);
895
896 MODULE_VERSION("0.0.1");
897 MODULE_LICENSE("GPL v2");
898 MODULE_AUTHOR("Michael S. Tsirkin");
899 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
WandBoard kernel