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xfs: add full xfs_dqblk verifier
[linux/fpc-iii.git] / drivers / vhost / net.c
blob986058a57917f5b6ce0394d83206c08e161f4bd9
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/moduleparam.h>
16 #include <linux/mutex.h>
17 #include <linux/workqueue.h>
18 #include <linux/file.h>
19 #include <linux/slab.h>
20 #include <linux/sched/clock.h>
21 #include <linux/sched/signal.h>
22 #include <linux/vmalloc.h>
23
24 #include <linux/net.h>
25 #include <linux/if_packet.h>
26 #include <linux/if_arp.h>
27 #include <linux/if_tun.h>
28 #include <linux/if_macvlan.h>
29 #include <linux/if_tap.h>
30 #include <linux/if_vlan.h>
31 #include <linux/skb_array.h>
32 #include <linux/skbuff.h>
33
34 #include <net/sock.h>
35
36 #include "vhost.h"
37
38 static int experimental_zcopytx = 1;
39 module_param(experimental_zcopytx, int, 0444);
40 MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
41 " 1 -Enable; 0 - Disable");
42
43 /* Max number of bytes transferred before requeueing the job.
44 * Using this limit prevents one virtqueue from starving others. */
45 #define VHOST_NET_WEIGHT 0x80000
46
47 /* Max number of packets transferred before requeueing the job.
48 * Using this limit prevents one virtqueue from starving rx. */
49 #define VHOST_NET_PKT_WEIGHT(vq) ((vq)->num * 2)
50
51 /* MAX number of TX used buffers for outstanding zerocopy */
52 #define VHOST_MAX_PEND 128
53 #define VHOST_GOODCOPY_LEN 256
54
55 /*
56 * For transmit, used buffer len is unused; we override it to track buffer
57 * status internally; used for zerocopy tx only.
58 */
59 /* Lower device DMA failed */
60 #define VHOST_DMA_FAILED_LEN ((__force __virtio32)3)
61 /* Lower device DMA done */
62 #define VHOST_DMA_DONE_LEN ((__force __virtio32)2)
63 /* Lower device DMA in progress */
64 #define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1)
65 /* Buffer unused */
66 #define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0)
67
68 #define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN)
69
70 enum {
71 VHOST_NET_FEATURES = VHOST_FEATURES |
72 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
73 (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
74 (1ULL << VIRTIO_F_IOMMU_PLATFORM)
75 };
76
77 enum {
78 VHOST_NET_VQ_RX = 0,
79 VHOST_NET_VQ_TX = 1,
80 VHOST_NET_VQ_MAX = 2,
81 };
82
83 struct vhost_net_ubuf_ref {
84 /* refcount follows semantics similar to kref:
85 * 0: object is released
86 * 1: no outstanding ubufs
87 * >1: outstanding ubufs
88 */
89 atomic_t refcount;
90 wait_queue_head_t wait;
91 struct vhost_virtqueue *vq;
92 };
93
94 #define VHOST_RX_BATCH 64
95 struct vhost_net_buf {
96 void **queue;
97 int tail;
98 int head;
99 };
100
101 struct vhost_net_virtqueue {
102 struct vhost_virtqueue vq;
103 size_t vhost_hlen;
104 size_t sock_hlen;
105 /* vhost zerocopy support fields below: */
106 /* last used idx for outstanding DMA zerocopy buffers */
107 int upend_idx;
108 /* first used idx for DMA done zerocopy buffers */
109 int done_idx;
110 /* an array of userspace buffers info */
111 struct ubuf_info *ubuf_info;
112 /* Reference counting for outstanding ubufs.
113 * Protected by vq mutex. Writers must also take device mutex. */
114 struct vhost_net_ubuf_ref *ubufs;
115 struct ptr_ring *rx_ring;
116 struct vhost_net_buf rxq;
117 };
118
119 struct vhost_net {
120 struct vhost_dev dev;
121 struct vhost_net_virtqueue vqs[VHOST_NET_VQ_MAX];
122 struct vhost_poll poll[VHOST_NET_VQ_MAX];
123 /* Number of TX recently submitted.
124 * Protected by tx vq lock. */
125 unsigned tx_packets;
126 /* Number of times zerocopy TX recently failed.
127 * Protected by tx vq lock. */
128 unsigned tx_zcopy_err;
129 /* Flush in progress. Protected by tx vq lock. */
130 bool tx_flush;
131 };
132
133 static unsigned vhost_net_zcopy_mask __read_mostly;
134
135 static void *vhost_net_buf_get_ptr(struct vhost_net_buf *rxq)
136 {
137 if (rxq->tail != rxq->head)
138 return rxq->queue[rxq->head];
139 else
140 return NULL;
141 }
142
143 static int vhost_net_buf_get_size(struct vhost_net_buf *rxq)
144 {
145 return rxq->tail - rxq->head;
146 }
147
148 static int vhost_net_buf_is_empty(struct vhost_net_buf *rxq)
149 {
150 return rxq->tail == rxq->head;
151 }
152
153 static void *vhost_net_buf_consume(struct vhost_net_buf *rxq)
154 {
155 void *ret = vhost_net_buf_get_ptr(rxq);
156 ++rxq->head;
157 return ret;
158 }
159
160 static int vhost_net_buf_produce(struct vhost_net_virtqueue *nvq)
161 {
162 struct vhost_net_buf *rxq = &nvq->rxq;
163
164 rxq->head = 0;
165 rxq->tail = ptr_ring_consume_batched(nvq->rx_ring, rxq->queue,
166 VHOST_RX_BATCH);
167 return rxq->tail;
168 }
169
170 static void vhost_net_buf_unproduce(struct vhost_net_virtqueue *nvq)
171 {
172 struct vhost_net_buf *rxq = &nvq->rxq;
173
174 if (nvq->rx_ring && !vhost_net_buf_is_empty(rxq)) {
175 ptr_ring_unconsume(nvq->rx_ring, rxq->queue + rxq->head,
176 vhost_net_buf_get_size(rxq),
177 tun_ptr_free);
178 rxq->head = rxq->tail = 0;
179 }
180 }
181
182 static int vhost_net_buf_peek_len(void *ptr)
183 {
184 if (tun_is_xdp_buff(ptr)) {
185 struct xdp_buff *xdp = tun_ptr_to_xdp(ptr);
186
187 return xdp->data_end - xdp->data;
188 }
189
190 return __skb_array_len_with_tag(ptr);
191 }
192
193 static int vhost_net_buf_peek(struct vhost_net_virtqueue *nvq)
194 {
195 struct vhost_net_buf *rxq = &nvq->rxq;
196
197 if (!vhost_net_buf_is_empty(rxq))
198 goto out;
199
200 if (!vhost_net_buf_produce(nvq))
201 return 0;
202
203 out:
204 return vhost_net_buf_peek_len(vhost_net_buf_get_ptr(rxq));
205 }
206
207 static void vhost_net_buf_init(struct vhost_net_buf *rxq)
208 {
209 rxq->head = rxq->tail = 0;
210 }
211
212 static void vhost_net_enable_zcopy(int vq)
213 {
214 vhost_net_zcopy_mask |= 0x1 << vq;
215 }
216
217 static struct vhost_net_ubuf_ref *
218 vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy)
219 {
220 struct vhost_net_ubuf_ref *ubufs;
221 /* No zero copy backend? Nothing to count. */
222 if (!zcopy)
223 return NULL;
224 ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL);
225 if (!ubufs)
226 return ERR_PTR(-ENOMEM);
227 atomic_set(&ubufs->refcount, 1);
228 init_waitqueue_head(&ubufs->wait);
229 ubufs->vq = vq;
230 return ubufs;
231 }
232
233 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
234 {
235 int r = atomic_sub_return(1, &ubufs->refcount);
236 if (unlikely(!r))
237 wake_up(&ubufs->wait);
238 return r;
239 }
240
241 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs)
242 {
243 vhost_net_ubuf_put(ubufs);
244 wait_event(ubufs->wait, !atomic_read(&ubufs->refcount));
245 }
246
247 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs)
248 {
249 vhost_net_ubuf_put_and_wait(ubufs);
250 kfree(ubufs);
251 }
252
253 static void vhost_net_clear_ubuf_info(struct vhost_net *n)
254 {
255 int i;
256
257 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
258 kfree(n->vqs[i].ubuf_info);
259 n->vqs[i].ubuf_info = NULL;
260 }
261 }
262
263 static int vhost_net_set_ubuf_info(struct vhost_net *n)
264 {
265 bool zcopy;
266 int i;
267
268 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
269 zcopy = vhost_net_zcopy_mask & (0x1 << i);
270 if (!zcopy)
271 continue;
272 n->vqs[i].ubuf_info = kmalloc(sizeof(*n->vqs[i].ubuf_info) *
273 UIO_MAXIOV, GFP_KERNEL);
274 if (!n->vqs[i].ubuf_info)
275 goto err;
276 }
277 return 0;
278
279 err:
280 vhost_net_clear_ubuf_info(n);
281 return -ENOMEM;
282 }
283
284 static void vhost_net_vq_reset(struct vhost_net *n)
285 {
286 int i;
287
288 vhost_net_clear_ubuf_info(n);
289
290 for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
291 n->vqs[i].done_idx = 0;
292 n->vqs[i].upend_idx = 0;
293 n->vqs[i].ubufs = NULL;
294 n->vqs[i].vhost_hlen = 0;
295 n->vqs[i].sock_hlen = 0;
296 vhost_net_buf_init(&n->vqs[i].rxq);
297 }
298
299 }
300
301 static void vhost_net_tx_packet(struct vhost_net *net)
302 {
303 ++net->tx_packets;
304 if (net->tx_packets < 1024)
305 return;
306 net->tx_packets = 0;
307 net->tx_zcopy_err = 0;
308 }
309
310 static void vhost_net_tx_err(struct vhost_net *net)
311 {
312 ++net->tx_zcopy_err;
313 }
314
315 static bool vhost_net_tx_select_zcopy(struct vhost_net *net)
316 {
317 /* TX flush waits for outstanding DMAs to be done.
318 * Don't start new DMAs.
319 */
320 return !net->tx_flush &&
321 net->tx_packets / 64 >= net->tx_zcopy_err;
322 }
323
324 static bool vhost_sock_zcopy(struct socket *sock)
325 {
326 return unlikely(experimental_zcopytx) &&
327 sock_flag(sock->sk, SOCK_ZEROCOPY);
328 }
329
330 /* In case of DMA done not in order in lower device driver for some reason.
331 * upend_idx is used to track end of used idx, done_idx is used to track head
332 * of used idx. Once lower device DMA done contiguously, we will signal KVM
333 * guest used idx.
334 */
335 static void vhost_zerocopy_signal_used(struct vhost_net *net,
336 struct vhost_virtqueue *vq)
337 {
338 struct vhost_net_virtqueue *nvq =
339 container_of(vq, struct vhost_net_virtqueue, vq);
340 int i, add;
341 int j = 0;
342
343 for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
344 if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
345 vhost_net_tx_err(net);
346 if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
347 vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
348 ++j;
349 } else
350 break;
351 }
352 while (j) {
353 add = min(UIO_MAXIOV - nvq->done_idx, j);
354 vhost_add_used_and_signal_n(vq->dev, vq,
355 &vq->heads[nvq->done_idx], add);
356 nvq->done_idx = (nvq->done_idx + add) % UIO_MAXIOV;
357 j -= add;
358 }
359 }
360
361 static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success)
362 {
363 struct vhost_net_ubuf_ref *ubufs = ubuf->ctx;
364 struct vhost_virtqueue *vq = ubufs->vq;
365 int cnt;
366
367 rcu_read_lock_bh();
368
369 /* set len to mark this desc buffers done DMA */
370 vq->heads[ubuf->desc].len = success ?
371 VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;
372 cnt = vhost_net_ubuf_put(ubufs);
373
374 /*
375 * Trigger polling thread if guest stopped submitting new buffers:
376 * in this case, the refcount after decrement will eventually reach 1.
377 * We also trigger polling periodically after each 16 packets
378 * (the value 16 here is more or less arbitrary, it's tuned to trigger
379 * less than 10% of times).
380 */
381 if (cnt <= 1 || !(cnt % 16))
382 vhost_poll_queue(&vq->poll);
383
384 rcu_read_unlock_bh();
385 }
386
387 static inline unsigned long busy_clock(void)
388 {
389 return local_clock() >> 10;
390 }
391
392 static bool vhost_can_busy_poll(struct vhost_dev *dev,
393 unsigned long endtime)
394 {
395 return likely(!need_resched()) &&
396 likely(!time_after(busy_clock(), endtime)) &&
397 likely(!signal_pending(current)) &&
398 !vhost_has_work(dev);
399 }
400
401 static void vhost_net_disable_vq(struct vhost_net *n,
402 struct vhost_virtqueue *vq)
403 {
404 struct vhost_net_virtqueue *nvq =
405 container_of(vq, struct vhost_net_virtqueue, vq);
406 struct vhost_poll *poll = n->poll + (nvq - n->vqs);
407 if (!vq->private_data)
408 return;
409 vhost_poll_stop(poll);
410 }
411
412 static int vhost_net_enable_vq(struct vhost_net *n,
413 struct vhost_virtqueue *vq)
414 {
415 struct vhost_net_virtqueue *nvq =
416 container_of(vq, struct vhost_net_virtqueue, vq);
417 struct vhost_poll *poll = n->poll + (nvq - n->vqs);
418 struct socket *sock;
419
420 sock = vq->private_data;
421 if (!sock)
422 return 0;
423
424 return vhost_poll_start(poll, sock->file);
425 }
426
427 static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
428 struct vhost_virtqueue *vq,
429 struct iovec iov[], unsigned int iov_size,
430 unsigned int *out_num, unsigned int *in_num)
431 {
432 unsigned long uninitialized_var(endtime);
433 int r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
434 out_num, in_num, NULL, NULL);
435
436 if (r == vq->num && vq->busyloop_timeout) {
437 preempt_disable();
438 endtime = busy_clock() + vq->busyloop_timeout;
439 while (vhost_can_busy_poll(vq->dev, endtime) &&
440 vhost_vq_avail_empty(vq->dev, vq))
441 cpu_relax();
442 preempt_enable();
443 r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
444 out_num, in_num, NULL, NULL);
445 }
446
447 return r;
448 }
449
450 static bool vhost_exceeds_maxpend(struct vhost_net *net)
451 {
452 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
453 struct vhost_virtqueue *vq = &nvq->vq;
454
455 return (nvq->upend_idx + UIO_MAXIOV - nvq->done_idx) % UIO_MAXIOV >
456 min_t(unsigned int, VHOST_MAX_PEND, vq->num >> 2);
457 }
458
459 /* Expects to be always run from workqueue - which acts as
460 * read-size critical section for our kind of RCU. */
461 static void handle_tx(struct vhost_net *net)
462 {
463 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
464 struct vhost_virtqueue *vq = &nvq->vq;
465 unsigned out, in;
466 int head;
467 struct msghdr msg = {
468 .msg_name = NULL,
469 .msg_namelen = 0,
470 .msg_control = NULL,
471 .msg_controllen = 0,
472 .msg_flags = MSG_DONTWAIT,
473 };
474 size_t len, total_len = 0;
475 int err;
476 size_t hdr_size;
477 struct socket *sock;
478 struct vhost_net_ubuf_ref *uninitialized_var(ubufs);
479 bool zcopy, zcopy_used;
480 int sent_pkts = 0;
481
482 mutex_lock(&vq->mutex);
483 sock = vq->private_data;
484 if (!sock)
485 goto out;
486
487 if (!vq_iotlb_prefetch(vq))
488 goto out;
489
490 vhost_disable_notify(&net->dev, vq);
491 vhost_net_disable_vq(net, vq);
492
493 hdr_size = nvq->vhost_hlen;
494 zcopy = nvq->ubufs;
495
496 for (;;) {
497 /* Release DMAs done buffers first */
498 if (zcopy)
499 vhost_zerocopy_signal_used(net, vq);
500
501
502 head = vhost_net_tx_get_vq_desc(net, vq, vq->iov,
503 ARRAY_SIZE(vq->iov),
504 &out, &in);
505 /* On error, stop handling until the next kick. */
506 if (unlikely(head < 0))
507 break;
508 /* Nothing new? Wait for eventfd to tell us they refilled. */
509 if (head == vq->num) {
510 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
511 vhost_disable_notify(&net->dev, vq);
512 continue;
513 }
514 break;
515 }
516 if (in) {
517 vq_err(vq, "Unexpected descriptor format for TX: "
518 "out %d, int %d\n", out, in);
519 break;
520 }
521 /* Skip header. TODO: support TSO. */
522 len = iov_length(vq->iov, out);
523 iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len);
524 iov_iter_advance(&msg.msg_iter, hdr_size);
525 /* Sanity check */
526 if (!msg_data_left(&msg)) {
527 vq_err(vq, "Unexpected header len for TX: "
528 "%zd expected %zd\n",
529 len, hdr_size);
530 break;
531 }
532 len = msg_data_left(&msg);
533
534 zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN
535 && !vhost_exceeds_maxpend(net)
536 && vhost_net_tx_select_zcopy(net);
537
538 /* use msg_control to pass vhost zerocopy ubuf info to skb */
539 if (zcopy_used) {
540 struct ubuf_info *ubuf;
541 ubuf = nvq->ubuf_info + nvq->upend_idx;
542
543 vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head);
544 vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
545 ubuf->callback = vhost_zerocopy_callback;
546 ubuf->ctx = nvq->ubufs;
547 ubuf->desc = nvq->upend_idx;
548 refcount_set(&ubuf->refcnt, 1);
549 msg.msg_control = ubuf;
550 msg.msg_controllen = sizeof(ubuf);
551 ubufs = nvq->ubufs;
552 atomic_inc(&ubufs->refcount);
553 nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
554 } else {
555 msg.msg_control = NULL;
556 ubufs = NULL;
557 }
558
559 total_len += len;
560 if (total_len < VHOST_NET_WEIGHT &&
561 !vhost_vq_avail_empty(&net->dev, vq) &&
562 likely(!vhost_exceeds_maxpend(net))) {
563 msg.msg_flags |= MSG_MORE;
564 } else {
565 msg.msg_flags &= ~MSG_MORE;
566 }
567
568 /* TODO: Check specific error and bomb out unless ENOBUFS? */
569 err = sock->ops->sendmsg(sock, &msg, len);
570 if (unlikely(err < 0)) {
571 if (zcopy_used) {
572 vhost_net_ubuf_put(ubufs);
573 nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
574 % UIO_MAXIOV;
575 }
576 vhost_discard_vq_desc(vq, 1);
577 vhost_net_enable_vq(net, vq);
578 break;
579 }
580 if (err != len)
581 pr_debug("Truncated TX packet: "
582 " len %d != %zd\n", err, len);
583 if (!zcopy_used)
584 vhost_add_used_and_signal(&net->dev, vq, head, 0);
585 else
586 vhost_zerocopy_signal_used(net, vq);
587 vhost_net_tx_packet(net);
588 if (unlikely(total_len >= VHOST_NET_WEIGHT) ||
589 unlikely(++sent_pkts >= VHOST_NET_PKT_WEIGHT(vq))) {
590 vhost_poll_queue(&vq->poll);
591 break;
592 }
593 }
594 out:
595 mutex_unlock(&vq->mutex);
596 }
597
598 static int peek_head_len(struct vhost_net_virtqueue *rvq, struct sock *sk)
599 {
600 struct sk_buff *head;
601 int len = 0;
602 unsigned long flags;
603
604 if (rvq->rx_ring)
605 return vhost_net_buf_peek(rvq);
606
607 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
608 head = skb_peek(&sk->sk_receive_queue);
609 if (likely(head)) {
610 len = head->len;
611 if (skb_vlan_tag_present(head))
612 len += VLAN_HLEN;
613 }
614
615 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
616 return len;
617 }
618
619 static int sk_has_rx_data(struct sock *sk)
620 {
621 struct socket *sock = sk->sk_socket;
622
623 if (sock->ops->peek_len)
624 return sock->ops->peek_len(sock);
625
626 return skb_queue_empty(&sk->sk_receive_queue);
627 }
628
629 static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk)
630 {
631 struct vhost_net_virtqueue *rvq = &net->vqs[VHOST_NET_VQ_RX];
632 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
633 struct vhost_virtqueue *vq = &nvq->vq;
634 unsigned long uninitialized_var(endtime);
635 int len = peek_head_len(rvq, sk);
636
637 if (!len && vq->busyloop_timeout) {
638 /* Both tx vq and rx socket were polled here */
639 mutex_lock_nested(&vq->mutex, 1);
640 vhost_disable_notify(&net->dev, vq);
641
642 preempt_disable();
643 endtime = busy_clock() + vq->busyloop_timeout;
644
645 while (vhost_can_busy_poll(&net->dev, endtime) &&
646 !sk_has_rx_data(sk) &&
647 vhost_vq_avail_empty(&net->dev, vq))
648 cpu_relax();
649
650 preempt_enable();
651
652 if (!vhost_vq_avail_empty(&net->dev, vq))
653 vhost_poll_queue(&vq->poll);
654 else if (unlikely(vhost_enable_notify(&net->dev, vq))) {
655 vhost_disable_notify(&net->dev, vq);
656 vhost_poll_queue(&vq->poll);
657 }
658
659 mutex_unlock(&vq->mutex);
660
661 len = peek_head_len(rvq, sk);
662 }
663
664 return len;
665 }
666
667 /* This is a multi-buffer version of vhost_get_desc, that works if
668 * vq has read descriptors only.
669 * @vq - the relevant virtqueue
670 * @datalen - data length we'll be reading
671 * @iovcount - returned count of io vectors we fill
672 * @log - vhost log
673 * @log_num - log offset
674 * @quota - headcount quota, 1 for big buffer
675 * returns number of buffer heads allocated, negative on error
676 */
677 static int get_rx_bufs(struct vhost_virtqueue *vq,
678 struct vring_used_elem *heads,
679 int datalen,
680 unsigned *iovcount,
681 struct vhost_log *log,
682 unsigned *log_num,
683 unsigned int quota)
684 {
685 unsigned int out, in;
686 int seg = 0;
687 int headcount = 0;
688 unsigned d;
689 int r, nlogs = 0;
690 /* len is always initialized before use since we are always called with
691 * datalen > 0.
692 */
693 u32 uninitialized_var(len);
694
695 while (datalen > 0 && headcount < quota) {
696 if (unlikely(seg >= UIO_MAXIOV)) {
697 r = -ENOBUFS;
698 goto err;
699 }
700 r = vhost_get_vq_desc(vq, vq->iov + seg,
701 ARRAY_SIZE(vq->iov) - seg, &out,
702 &in, log, log_num);
703 if (unlikely(r < 0))
704 goto err;
705
706 d = r;
707 if (d == vq->num) {
708 r = 0;
709 goto err;
710 }
711 if (unlikely(out || in <= 0)) {
712 vq_err(vq, "unexpected descriptor format for RX: "
713 "out %d, in %d\n", out, in);
714 r = -EINVAL;
715 goto err;
716 }
717 if (unlikely(log)) {
718 nlogs += *log_num;
719 log += *log_num;
720 }
721 heads[headcount].id = cpu_to_vhost32(vq, d);
722 len = iov_length(vq->iov + seg, in);
723 heads[headcount].len = cpu_to_vhost32(vq, len);
724 datalen -= len;
725 ++headcount;
726 seg += in;
727 }
728 heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen);
729 *iovcount = seg;
730 if (unlikely(log))
731 *log_num = nlogs;
732
733 /* Detect overrun */
734 if (unlikely(datalen > 0)) {
735 r = UIO_MAXIOV + 1;
736 goto err;
737 }
738 return headcount;
739 err:
740 vhost_discard_vq_desc(vq, headcount);
741 return r;
742 }
743
744 /* Expects to be always run from workqueue - which acts as
745 * read-size critical section for our kind of RCU. */
746 static void handle_rx(struct vhost_net *net)
747 {
748 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX];
749 struct vhost_virtqueue *vq = &nvq->vq;
750 unsigned uninitialized_var(in), log;
751 struct vhost_log *vq_log;
752 struct msghdr msg = {
753 .msg_name = NULL,
754 .msg_namelen = 0,
755 .msg_control = NULL, /* FIXME: get and handle RX aux data. */
756 .msg_controllen = 0,
757 .msg_flags = MSG_DONTWAIT,
758 };
759 struct virtio_net_hdr hdr = {
760 .flags = 0,
761 .gso_type = VIRTIO_NET_HDR_GSO_NONE
762 };
763 size_t total_len = 0;
764 int err, mergeable;
765 s16 headcount, nheads = 0;
766 size_t vhost_hlen, sock_hlen;
767 size_t vhost_len, sock_len;
768 struct socket *sock;
769 struct iov_iter fixup;
770 __virtio16 num_buffers;
771
772 mutex_lock_nested(&vq->mutex, 0);
773 sock = vq->private_data;
774 if (!sock)
775 goto out;
776
777 if (!vq_iotlb_prefetch(vq))
778 goto out;
779
780 vhost_disable_notify(&net->dev, vq);
781 vhost_net_disable_vq(net, vq);
782
783 vhost_hlen = nvq->vhost_hlen;
784 sock_hlen = nvq->sock_hlen;
785
786 vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ?
787 vq->log : NULL;
788 mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
789
790 while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk))) {
791 sock_len += sock_hlen;
792 vhost_len = sock_len + vhost_hlen;
793 headcount = get_rx_bufs(vq, vq->heads + nheads, vhost_len,
794 &in, vq_log, &log,
795 likely(mergeable) ? UIO_MAXIOV : 1);
796 /* On error, stop handling until the next kick. */
797 if (unlikely(headcount < 0))
798 goto out;
799 /* OK, now we need to know about added descriptors. */
800 if (!headcount) {
801 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
802 /* They have slipped one in as we were
803 * doing that: check again. */
804 vhost_disable_notify(&net->dev, vq);
805 continue;
806 }
807 /* Nothing new? Wait for eventfd to tell us
808 * they refilled. */
809 goto out;
810 }
811 if (nvq->rx_ring)
812 msg.msg_control = vhost_net_buf_consume(&nvq->rxq);
813 /* On overrun, truncate and discard */
814 if (unlikely(headcount > UIO_MAXIOV)) {
815 iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1);
816 err = sock->ops->recvmsg(sock, &msg,
817 1, MSG_DONTWAIT | MSG_TRUNC);
818 pr_debug("Discarded rx packet: len %zd\n", sock_len);
819 continue;
820 }
821 /* We don't need to be notified again. */
822 iov_iter_init(&msg.msg_iter, READ, vq->iov, in, vhost_len);
823 fixup = msg.msg_iter;
824 if (unlikely((vhost_hlen))) {
825 /* We will supply the header ourselves
826 * TODO: support TSO.
827 */
828 iov_iter_advance(&msg.msg_iter, vhost_hlen);
829 }
830 err = sock->ops->recvmsg(sock, &msg,
831 sock_len, MSG_DONTWAIT | MSG_TRUNC);
832 /* Userspace might have consumed the packet meanwhile:
833 * it's not supposed to do this usually, but might be hard
834 * to prevent. Discard data we got (if any) and keep going. */
835 if (unlikely(err != sock_len)) {
836 pr_debug("Discarded rx packet: "
837 " len %d, expected %zd\n", err, sock_len);
838 vhost_discard_vq_desc(vq, headcount);
839 continue;
840 }
841 /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
842 if (unlikely(vhost_hlen)) {
843 if (copy_to_iter(&hdr, sizeof(hdr),
844 &fixup) != sizeof(hdr)) {
845 vq_err(vq, "Unable to write vnet_hdr "
846 "at addr %p\n", vq->iov->iov_base);
847 goto out;
848 }
849 } else {
850 /* Header came from socket; we'll need to patch
851 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF
852 */
853 iov_iter_advance(&fixup, sizeof(hdr));
854 }
855 /* TODO: Should check and handle checksum. */
856
857 num_buffers = cpu_to_vhost16(vq, headcount);
858 if (likely(mergeable) &&
859 copy_to_iter(&num_buffers, sizeof num_buffers,
860 &fixup) != sizeof num_buffers) {
861 vq_err(vq, "Failed num_buffers write");
862 vhost_discard_vq_desc(vq, headcount);
863 goto out;
864 }
865 nheads += headcount;
866 if (nheads > VHOST_RX_BATCH) {
867 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
868 nheads);
869 nheads = 0;
870 }
871 if (unlikely(vq_log))
872 vhost_log_write(vq, vq_log, log, vhost_len);
873 total_len += vhost_len;
874 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
875 vhost_poll_queue(&vq->poll);
876 goto out;
877 }
878 }
879 vhost_net_enable_vq(net, vq);
880 out:
881 if (nheads)
882 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
883 nheads);
884 mutex_unlock(&vq->mutex);
885 }
886
887 static void handle_tx_kick(struct vhost_work *work)
888 {
889 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
890 poll.work);
891 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
892
893 handle_tx(net);
894 }
895
896 static void handle_rx_kick(struct vhost_work *work)
897 {
898 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
899 poll.work);
900 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
901
902 handle_rx(net);
903 }
904
905 static void handle_tx_net(struct vhost_work *work)
906 {
907 struct vhost_net *net = container_of(work, struct vhost_net,
908 poll[VHOST_NET_VQ_TX].work);
909 handle_tx(net);
910 }
911
912 static void handle_rx_net(struct vhost_work *work)
913 {
914 struct vhost_net *net = container_of(work, struct vhost_net,
915 poll[VHOST_NET_VQ_RX].work);
916 handle_rx(net);
917 }
918
919 static int vhost_net_open(struct inode *inode, struct file *f)
920 {
921 struct vhost_net *n;
922 struct vhost_dev *dev;
923 struct vhost_virtqueue **vqs;
924 void **queue;
925 int i;
926
927 n = kvmalloc(sizeof *n, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
928 if (!n)
929 return -ENOMEM;
930 vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
931 if (!vqs) {
932 kvfree(n);
933 return -ENOMEM;
934 }
935
936 queue = kmalloc_array(VHOST_RX_BATCH, sizeof(void *),
937 GFP_KERNEL);
938 if (!queue) {
939 kfree(vqs);
940 kvfree(n);
941 return -ENOMEM;
942 }
943 n->vqs[VHOST_NET_VQ_RX].rxq.queue = queue;
944
945 dev = &n->dev;
946 vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq;
947 vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq;
948 n->vqs[VHOST_NET_VQ_TX].vq.handle_kick = handle_tx_kick;
949 n->vqs[VHOST_NET_VQ_RX].vq.handle_kick = handle_rx_kick;
950 for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
951 n->vqs[i].ubufs = NULL;
952 n->vqs[i].ubuf_info = NULL;
953 n->vqs[i].upend_idx = 0;
954 n->vqs[i].done_idx = 0;
955 n->vqs[i].vhost_hlen = 0;
956 n->vqs[i].sock_hlen = 0;
957 n->vqs[i].rx_ring = NULL;
958 vhost_net_buf_init(&n->vqs[i].rxq);
959 }
960 vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);
961
962 vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev);
963 vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev);
964
965 f->private_data = n;
966
967 return 0;
968 }
969
970 static struct socket *vhost_net_stop_vq(struct vhost_net *n,
971 struct vhost_virtqueue *vq)
972 {
973 struct socket *sock;
974 struct vhost_net_virtqueue *nvq =
975 container_of(vq, struct vhost_net_virtqueue, vq);
976
977 mutex_lock(&vq->mutex);
978 sock = vq->private_data;
979 vhost_net_disable_vq(n, vq);
980 vq->private_data = NULL;
981 vhost_net_buf_unproduce(nvq);
982 nvq->rx_ring = NULL;
983 mutex_unlock(&vq->mutex);
984 return sock;
985 }
986
987 static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
988 struct socket **rx_sock)
989 {
990 *tx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_TX].vq);
991 *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq);
992 }
993
994 static void vhost_net_flush_vq(struct vhost_net *n, int index)
995 {
996 vhost_poll_flush(n->poll + index);
997 vhost_poll_flush(&n->vqs[index].vq.poll);
998 }
999
1000 static void vhost_net_flush(struct vhost_net *n)
1001 {
1002 vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
1003 vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
1004 if (n->vqs[VHOST_NET_VQ_TX].ubufs) {
1005 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
1006 n->tx_flush = true;
1007 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
1008 /* Wait for all lower device DMAs done. */
1009 vhost_net_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs);
1010 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
1011 n->tx_flush = false;
1012 atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1);
1013 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
1014 }
1015 }
1016
1017 static int vhost_net_release(struct inode *inode, struct file *f)
1018 {
1019 struct vhost_net *n = f->private_data;
1020 struct socket *tx_sock;
1021 struct socket *rx_sock;
1022
1023 vhost_net_stop(n, &tx_sock, &rx_sock);
1024 vhost_net_flush(n);
1025 vhost_dev_stop(&n->dev);
1026 vhost_dev_cleanup(&n->dev);
1027 vhost_net_vq_reset(n);
1028 if (tx_sock)
1029 sockfd_put(tx_sock);
1030 if (rx_sock)
1031 sockfd_put(rx_sock);
1032 /* Make sure no callbacks are outstanding */
1033 synchronize_rcu_bh();
1034 /* We do an extra flush before freeing memory,
1035 * since jobs can re-queue themselves. */
1036 vhost_net_flush(n);
1037 kfree(n->vqs[VHOST_NET_VQ_RX].rxq.queue);
1038 kfree(n->dev.vqs);
1039 kvfree(n);
1040 return 0;
1041 }
1042
1043 static struct socket *get_raw_socket(int fd)
1044 {
1045 struct {
1046 struct sockaddr_ll sa;
1047 char buf[MAX_ADDR_LEN];
1048 } uaddr;
1049 int r;
1050 struct socket *sock = sockfd_lookup(fd, &r);
1051
1052 if (!sock)
1053 return ERR_PTR(-ENOTSOCK);
1054
1055 /* Parameter checking */
1056 if (sock->sk->sk_type != SOCK_RAW) {
1057 r = -ESOCKTNOSUPPORT;
1058 goto err;
1059 }
1060
1061 r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, 0);
1062 if (r < 0)
1063 goto err;
1064
1065 if (uaddr.sa.sll_family != AF_PACKET) {
1066 r = -EPFNOSUPPORT;
1067 goto err;
1068 }
1069 return sock;
1070 err:
1071 sockfd_put(sock);
1072 return ERR_PTR(r);
1073 }
1074
1075 static struct ptr_ring *get_tap_ptr_ring(int fd)
1076 {
1077 struct ptr_ring *ring;
1078 struct file *file = fget(fd);
1079
1080 if (!file)
1081 return NULL;
1082 ring = tun_get_tx_ring(file);
1083 if (!IS_ERR(ring))
1084 goto out;
1085 ring = tap_get_ptr_ring(file);
1086 if (!IS_ERR(ring))
1087 goto out;
1088 ring = NULL;
1089 out:
1090 fput(file);
1091 return ring;
1092 }
1093
1094 static struct socket *get_tap_socket(int fd)
1095 {
1096 struct file *file = fget(fd);
1097 struct socket *sock;
1098
1099 if (!file)
1100 return ERR_PTR(-EBADF);
1101 sock = tun_get_socket(file);
1102 if (!IS_ERR(sock))
1103 return sock;
1104 sock = tap_get_socket(file);
1105 if (IS_ERR(sock))
1106 fput(file);
1107 return sock;
1108 }
1109
1110 static struct socket *get_socket(int fd)
1111 {
1112 struct socket *sock;
1113
1114 /* special case to disable backend */
1115 if (fd == -1)
1116 return NULL;
1117 sock = get_raw_socket(fd);
1118 if (!IS_ERR(sock))
1119 return sock;
1120 sock = get_tap_socket(fd);
1121 if (!IS_ERR(sock))
1122 return sock;
1123 return ERR_PTR(-ENOTSOCK);
1124 }
1125
1126 static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
1127 {
1128 struct socket *sock, *oldsock;
1129 struct vhost_virtqueue *vq;
1130 struct vhost_net_virtqueue *nvq;
1131 struct vhost_net_ubuf_ref *ubufs, *oldubufs = NULL;
1132 int r;
1133
1134 mutex_lock(&n->dev.mutex);
1135 r = vhost_dev_check_owner(&n->dev);
1136 if (r)
1137 goto err;
1138
1139 if (index >= VHOST_NET_VQ_MAX) {
1140 r = -ENOBUFS;
1141 goto err;
1142 }
1143 vq = &n->vqs[index].vq;
1144 nvq = &n->vqs[index];
1145 mutex_lock(&vq->mutex);
1146
1147 /* Verify that ring has been setup correctly. */
1148 if (!vhost_vq_access_ok(vq)) {
1149 r = -EFAULT;
1150 goto err_vq;
1151 }
1152 sock = get_socket(fd);
1153 if (IS_ERR(sock)) {
1154 r = PTR_ERR(sock);
1155 goto err_vq;
1156 }
1157
1158 /* start polling new socket */
1159 oldsock = vq->private_data;
1160 if (sock != oldsock) {
1161 ubufs = vhost_net_ubuf_alloc(vq,
1162 sock && vhost_sock_zcopy(sock));
1163 if (IS_ERR(ubufs)) {
1164 r = PTR_ERR(ubufs);
1165 goto err_ubufs;
1166 }
1167
1168 vhost_net_disable_vq(n, vq);
1169 vq->private_data = sock;
1170 vhost_net_buf_unproduce(nvq);
1171 r = vhost_vq_init_access(vq);
1172 if (r)
1173 goto err_used;
1174 r = vhost_net_enable_vq(n, vq);
1175 if (r)
1176 goto err_used;
1177 if (index == VHOST_NET_VQ_RX)
1178 nvq->rx_ring = get_tap_ptr_ring(fd);
1179
1180 oldubufs = nvq->ubufs;
1181 nvq->ubufs = ubufs;
1182
1183 n->tx_packets = 0;
1184 n->tx_zcopy_err = 0;
1185 n->tx_flush = false;
1186 }
1187
1188 mutex_unlock(&vq->mutex);
1189
1190 if (oldubufs) {
1191 vhost_net_ubuf_put_wait_and_free(oldubufs);
1192 mutex_lock(&vq->mutex);
1193 vhost_zerocopy_signal_used(n, vq);
1194 mutex_unlock(&vq->mutex);
1195 }
1196
1197 if (oldsock) {
1198 vhost_net_flush_vq(n, index);
1199 sockfd_put(oldsock);
1200 }
1201
1202 mutex_unlock(&n->dev.mutex);
1203 return 0;
1204
1205 err_used:
1206 vq->private_data = oldsock;
1207 vhost_net_enable_vq(n, vq);
1208 if (ubufs)
1209 vhost_net_ubuf_put_wait_and_free(ubufs);
1210 err_ubufs:
1211 sockfd_put(sock);
1212 err_vq:
1213 mutex_unlock(&vq->mutex);
1214 err:
1215 mutex_unlock(&n->dev.mutex);
1216 return r;
1217 }
1218
1219 static long vhost_net_reset_owner(struct vhost_net *n)
1220 {
1221 struct socket *tx_sock = NULL;
1222 struct socket *rx_sock = NULL;
1223 long err;
1224 struct vhost_umem *umem;
1225
1226 mutex_lock(&n->dev.mutex);
1227 err = vhost_dev_check_owner(&n->dev);
1228 if (err)
1229 goto done;
1230 umem = vhost_dev_reset_owner_prepare();
1231 if (!umem) {
1232 err = -ENOMEM;
1233 goto done;
1234 }
1235 vhost_net_stop(n, &tx_sock, &rx_sock);
1236 vhost_net_flush(n);
1237 vhost_dev_stop(&n->dev);
1238 vhost_dev_reset_owner(&n->dev, umem);
1239 vhost_net_vq_reset(n);
1240 done:
1241 mutex_unlock(&n->dev.mutex);
1242 if (tx_sock)
1243 sockfd_put(tx_sock);
1244 if (rx_sock)
1245 sockfd_put(rx_sock);
1246 return err;
1247 }
1248
1249 static int vhost_net_set_features(struct vhost_net *n, u64 features)
1250 {
1251 size_t vhost_hlen, sock_hlen, hdr_len;
1252 int i;
1253
1254 hdr_len = (features & ((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
1255 (1ULL << VIRTIO_F_VERSION_1))) ?
1256 sizeof(struct virtio_net_hdr_mrg_rxbuf) :
1257 sizeof(struct virtio_net_hdr);
1258 if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
1259 /* vhost provides vnet_hdr */
1260 vhost_hlen = hdr_len;
1261 sock_hlen = 0;
1262 } else {
1263 /* socket provides vnet_hdr */
1264 vhost_hlen = 0;
1265 sock_hlen = hdr_len;
1266 }
1267 mutex_lock(&n->dev.mutex);
1268 if ((features & (1 << VHOST_F_LOG_ALL)) &&
1269 !vhost_log_access_ok(&n->dev))
1270 goto out_unlock;
1271
1272 if ((features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) {
1273 if (vhost_init_device_iotlb(&n->dev, true))
1274 goto out_unlock;
1275 }
1276
1277 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
1278 mutex_lock(&n->vqs[i].vq.mutex);
1279 n->vqs[i].vq.acked_features = features;
1280 n->vqs[i].vhost_hlen = vhost_hlen;
1281 n->vqs[i].sock_hlen = sock_hlen;
1282 mutex_unlock(&n->vqs[i].vq.mutex);
1283 }
1284 mutex_unlock(&n->dev.mutex);
1285 return 0;
1286
1287 out_unlock:
1288 mutex_unlock(&n->dev.mutex);
1289 return -EFAULT;
1290 }
1291
1292 static long vhost_net_set_owner(struct vhost_net *n)
1293 {
1294 int r;
1295
1296 mutex_lock(&n->dev.mutex);
1297 if (vhost_dev_has_owner(&n->dev)) {
1298 r = -EBUSY;
1299 goto out;
1300 }
1301 r = vhost_net_set_ubuf_info(n);
1302 if (r)
1303 goto out;
1304 r = vhost_dev_set_owner(&n->dev);
1305 if (r)
1306 vhost_net_clear_ubuf_info(n);
1307 vhost_net_flush(n);
1308 out:
1309 mutex_unlock(&n->dev.mutex);
1310 return r;
1311 }
1312
1313 static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
1314 unsigned long arg)
1315 {
1316 struct vhost_net *n = f->private_data;
1317 void __user *argp = (void __user *)arg;
1318 u64 __user *featurep = argp;
1319 struct vhost_vring_file backend;
1320 u64 features;
1321 int r;
1322
1323 switch (ioctl) {
1324 case VHOST_NET_SET_BACKEND:
1325 if (copy_from_user(&backend, argp, sizeof backend))
1326 return -EFAULT;
1327 return vhost_net_set_backend(n, backend.index, backend.fd);
1328 case VHOST_GET_FEATURES:
1329 features = VHOST_NET_FEATURES;
1330 if (copy_to_user(featurep, &features, sizeof features))
1331 return -EFAULT;
1332 return 0;
1333 case VHOST_SET_FEATURES:
1334 if (copy_from_user(&features, featurep, sizeof features))
1335 return -EFAULT;
1336 if (features & ~VHOST_NET_FEATURES)
1337 return -EOPNOTSUPP;
1338 return vhost_net_set_features(n, features);
1339 case VHOST_RESET_OWNER:
1340 return vhost_net_reset_owner(n);
1341 case VHOST_SET_OWNER:
1342 return vhost_net_set_owner(n);
1343 default:
1344 mutex_lock(&n->dev.mutex);
1345 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
1346 if (r == -ENOIOCTLCMD)
1347 r = vhost_vring_ioctl(&n->dev, ioctl, argp);
1348 else
1349 vhost_net_flush(n);
1350 mutex_unlock(&n->dev.mutex);
1351 return r;
1352 }
1353 }
1354
1355 #ifdef CONFIG_COMPAT
1356 static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
1357 unsigned long arg)
1358 {
1359 return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1360 }
1361 #endif
1362
1363 static ssize_t vhost_net_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1364 {
1365 struct file *file = iocb->ki_filp;
1366 struct vhost_net *n = file->private_data;
1367 struct vhost_dev *dev = &n->dev;
1368 int noblock = file->f_flags & O_NONBLOCK;
1369
1370 return vhost_chr_read_iter(dev, to, noblock);
1371 }
1372
1373 static ssize_t vhost_net_chr_write_iter(struct kiocb *iocb,
1374 struct iov_iter *from)
1375 {
1376 struct file *file = iocb->ki_filp;
1377 struct vhost_net *n = file->private_data;
1378 struct vhost_dev *dev = &n->dev;
1379
1380 return vhost_chr_write_iter(dev, from);
1381 }
1382
1383 static __poll_t vhost_net_chr_poll(struct file *file, poll_table *wait)
1384 {
1385 struct vhost_net *n = file->private_data;
1386 struct vhost_dev *dev = &n->dev;
1387
1388 return vhost_chr_poll(file, dev, wait);
1389 }
1390
1391 static const struct file_operations vhost_net_fops = {
1392 .owner = THIS_MODULE,
1393 .release = vhost_net_release,
1394 .read_iter = vhost_net_chr_read_iter,
1395 .write_iter = vhost_net_chr_write_iter,
1396 .poll = vhost_net_chr_poll,
1397 .unlocked_ioctl = vhost_net_ioctl,
1398 #ifdef CONFIG_COMPAT
1399 .compat_ioctl = vhost_net_compat_ioctl,
1400 #endif
1401 .open = vhost_net_open,
1402 .llseek = noop_llseek,
1403 };
1404
1405 static struct miscdevice vhost_net_misc = {
1406 .minor = VHOST_NET_MINOR,
1407 .name = "vhost-net",
1408 .fops = &vhost_net_fops,
1409 };
1410
1411 static int vhost_net_init(void)
1412 {
1413 if (experimental_zcopytx)
1414 vhost_net_enable_zcopy(VHOST_NET_VQ_TX);
1415 return misc_register(&vhost_net_misc);
1416 }
1417 module_init(vhost_net_init);
1418
1419 static void vhost_net_exit(void)
1420 {
1421 misc_deregister(&vhost_net_misc);
1422 }
1423 module_exit(vhost_net_exit);
1424
1425 MODULE_VERSION("0.0.1");
1426 MODULE_LICENSE("GPL v2");
1427 MODULE_AUTHOR("Michael S. Tsirkin");
1428 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1429 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
1430 MODULE_ALIAS("devname:vhost-net");
Linux with added FPC-III support