Linux 4.1.16
[linux/fpc-iii.git] / drivers / vhost / net.c
blob7d137a43cc86842ed98bc27e63d6dfcb2042f177
1 /* Copyright (C) 2009 Red Hat, Inc.
2 * Author: Michael S. Tsirkin <mst@redhat.com>
4 * This work is licensed under the terms of the GNU GPL, version 2.
6 * virtio-net server in host kernel.
7 */
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/vmalloc.h>
22 #include <linux/net.h>
23 #include <linux/if_packet.h>
24 #include <linux/if_arp.h>
25 #include <linux/if_tun.h>
26 #include <linux/if_macvlan.h>
27 #include <linux/if_vlan.h>
29 #include <net/sock.h>
31 #include "vhost.h"
33 static int experimental_zcopytx = 1;
34 module_param(experimental_zcopytx, int, 0444);
35 MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
36 " 1 -Enable; 0 - Disable");
38 /* Max number of bytes transferred before requeueing the job.
39 * Using this limit prevents one virtqueue from starving others. */
40 #define VHOST_NET_WEIGHT 0x80000
42 /* MAX number of TX used buffers for outstanding zerocopy */
43 #define VHOST_MAX_PEND 128
44 #define VHOST_GOODCOPY_LEN 256
47 * For transmit, used buffer len is unused; we override it to track buffer
48 * status internally; used for zerocopy tx only.
50 /* Lower device DMA failed */
51 #define VHOST_DMA_FAILED_LEN ((__force __virtio32)3)
52 /* Lower device DMA done */
53 #define VHOST_DMA_DONE_LEN ((__force __virtio32)2)
54 /* Lower device DMA in progress */
55 #define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1)
56 /* Buffer unused */
57 #define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0)
59 #define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN)
61 enum {
62 VHOST_NET_FEATURES = VHOST_FEATURES |
63 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
64 (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
65 (1ULL << VIRTIO_F_VERSION_1),
68 enum {
69 VHOST_NET_VQ_RX = 0,
70 VHOST_NET_VQ_TX = 1,
71 VHOST_NET_VQ_MAX = 2,
74 struct vhost_net_ubuf_ref {
75 /* refcount follows semantics similar to kref:
76 * 0: object is released
77 * 1: no outstanding ubufs
78 * >1: outstanding ubufs
80 atomic_t refcount;
81 wait_queue_head_t wait;
82 struct vhost_virtqueue *vq;
85 struct vhost_net_virtqueue {
86 struct vhost_virtqueue vq;
87 size_t vhost_hlen;
88 size_t sock_hlen;
89 /* vhost zerocopy support fields below: */
90 /* last used idx for outstanding DMA zerocopy buffers */
91 int upend_idx;
92 /* first used idx for DMA done zerocopy buffers */
93 int done_idx;
94 /* an array of userspace buffers info */
95 struct ubuf_info *ubuf_info;
96 /* Reference counting for outstanding ubufs.
97 * Protected by vq mutex. Writers must also take device mutex. */
98 struct vhost_net_ubuf_ref *ubufs;
101 struct vhost_net {
102 struct vhost_dev dev;
103 struct vhost_net_virtqueue vqs[VHOST_NET_VQ_MAX];
104 struct vhost_poll poll[VHOST_NET_VQ_MAX];
105 /* Number of TX recently submitted.
106 * Protected by tx vq lock. */
107 unsigned tx_packets;
108 /* Number of times zerocopy TX recently failed.
109 * Protected by tx vq lock. */
110 unsigned tx_zcopy_err;
111 /* Flush in progress. Protected by tx vq lock. */
112 bool tx_flush;
115 static unsigned vhost_net_zcopy_mask __read_mostly;
117 static void vhost_net_enable_zcopy(int vq)
119 vhost_net_zcopy_mask |= 0x1 << vq;
122 static struct vhost_net_ubuf_ref *
123 vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy)
125 struct vhost_net_ubuf_ref *ubufs;
126 /* No zero copy backend? Nothing to count. */
127 if (!zcopy)
128 return NULL;
129 ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL);
130 if (!ubufs)
131 return ERR_PTR(-ENOMEM);
132 atomic_set(&ubufs->refcount, 1);
133 init_waitqueue_head(&ubufs->wait);
134 ubufs->vq = vq;
135 return ubufs;
138 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
140 int r = atomic_sub_return(1, &ubufs->refcount);
141 if (unlikely(!r))
142 wake_up(&ubufs->wait);
143 return r;
146 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs)
148 vhost_net_ubuf_put(ubufs);
149 wait_event(ubufs->wait, !atomic_read(&ubufs->refcount));
152 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs)
154 vhost_net_ubuf_put_and_wait(ubufs);
155 kfree(ubufs);
158 static void vhost_net_clear_ubuf_info(struct vhost_net *n)
160 int i;
162 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
163 kfree(n->vqs[i].ubuf_info);
164 n->vqs[i].ubuf_info = NULL;
168 static int vhost_net_set_ubuf_info(struct vhost_net *n)
170 bool zcopy;
171 int i;
173 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
174 zcopy = vhost_net_zcopy_mask & (0x1 << i);
175 if (!zcopy)
176 continue;
177 n->vqs[i].ubuf_info = kmalloc(sizeof(*n->vqs[i].ubuf_info) *
178 UIO_MAXIOV, GFP_KERNEL);
179 if (!n->vqs[i].ubuf_info)
180 goto err;
182 return 0;
184 err:
185 vhost_net_clear_ubuf_info(n);
186 return -ENOMEM;
189 static void vhost_net_vq_reset(struct vhost_net *n)
191 int i;
193 vhost_net_clear_ubuf_info(n);
195 for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
196 n->vqs[i].done_idx = 0;
197 n->vqs[i].upend_idx = 0;
198 n->vqs[i].ubufs = NULL;
199 n->vqs[i].vhost_hlen = 0;
200 n->vqs[i].sock_hlen = 0;
205 static void vhost_net_tx_packet(struct vhost_net *net)
207 ++net->tx_packets;
208 if (net->tx_packets < 1024)
209 return;
210 net->tx_packets = 0;
211 net->tx_zcopy_err = 0;
214 static void vhost_net_tx_err(struct vhost_net *net)
216 ++net->tx_zcopy_err;
219 static bool vhost_net_tx_select_zcopy(struct vhost_net *net)
221 /* TX flush waits for outstanding DMAs to be done.
222 * Don't start new DMAs.
224 return !net->tx_flush &&
225 net->tx_packets / 64 >= net->tx_zcopy_err;
228 static bool vhost_sock_zcopy(struct socket *sock)
230 return unlikely(experimental_zcopytx) &&
231 sock_flag(sock->sk, SOCK_ZEROCOPY);
234 /* In case of DMA done not in order in lower device driver for some reason.
235 * upend_idx is used to track end of used idx, done_idx is used to track head
236 * of used idx. Once lower device DMA done contiguously, we will signal KVM
237 * guest used idx.
239 static void vhost_zerocopy_signal_used(struct vhost_net *net,
240 struct vhost_virtqueue *vq)
242 struct vhost_net_virtqueue *nvq =
243 container_of(vq, struct vhost_net_virtqueue, vq);
244 int i, add;
245 int j = 0;
247 for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
248 if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
249 vhost_net_tx_err(net);
250 if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
251 vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
252 ++j;
253 } else
254 break;
256 while (j) {
257 add = min(UIO_MAXIOV - nvq->done_idx, j);
258 vhost_add_used_and_signal_n(vq->dev, vq,
259 &vq->heads[nvq->done_idx], add);
260 nvq->done_idx = (nvq->done_idx + add) % UIO_MAXIOV;
261 j -= add;
265 static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success)
267 struct vhost_net_ubuf_ref *ubufs = ubuf->ctx;
268 struct vhost_virtqueue *vq = ubufs->vq;
269 int cnt;
271 rcu_read_lock_bh();
273 /* set len to mark this desc buffers done DMA */
274 vq->heads[ubuf->desc].len = success ?
275 VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;
276 cnt = vhost_net_ubuf_put(ubufs);
279 * Trigger polling thread if guest stopped submitting new buffers:
280 * in this case, the refcount after decrement will eventually reach 1.
281 * We also trigger polling periodically after each 16 packets
282 * (the value 16 here is more or less arbitrary, it's tuned to trigger
283 * less than 10% of times).
285 if (cnt <= 1 || !(cnt % 16))
286 vhost_poll_queue(&vq->poll);
288 rcu_read_unlock_bh();
291 /* Expects to be always run from workqueue - which acts as
292 * read-size critical section for our kind of RCU. */
293 static void handle_tx(struct vhost_net *net)
295 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
296 struct vhost_virtqueue *vq = &nvq->vq;
297 unsigned out, in;
298 int head;
299 struct msghdr msg = {
300 .msg_name = NULL,
301 .msg_namelen = 0,
302 .msg_control = NULL,
303 .msg_controllen = 0,
304 .msg_flags = MSG_DONTWAIT,
306 size_t len, total_len = 0;
307 int err;
308 size_t hdr_size;
309 struct socket *sock;
310 struct vhost_net_ubuf_ref *uninitialized_var(ubufs);
311 bool zcopy, zcopy_used;
313 mutex_lock(&vq->mutex);
314 sock = vq->private_data;
315 if (!sock)
316 goto out;
318 vhost_disable_notify(&net->dev, vq);
320 hdr_size = nvq->vhost_hlen;
321 zcopy = nvq->ubufs;
323 for (;;) {
324 /* Release DMAs done buffers first */
325 if (zcopy)
326 vhost_zerocopy_signal_used(net, vq);
328 /* If more outstanding DMAs, queue the work.
329 * Handle upend_idx wrap around
331 if (unlikely((nvq->upend_idx + vq->num - VHOST_MAX_PEND)
332 % UIO_MAXIOV == nvq->done_idx))
333 break;
335 head = vhost_get_vq_desc(vq, vq->iov,
336 ARRAY_SIZE(vq->iov),
337 &out, &in,
338 NULL, NULL);
339 /* On error, stop handling until the next kick. */
340 if (unlikely(head < 0))
341 break;
342 /* Nothing new? Wait for eventfd to tell us they refilled. */
343 if (head == vq->num) {
344 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
345 vhost_disable_notify(&net->dev, vq);
346 continue;
348 break;
350 if (in) {
351 vq_err(vq, "Unexpected descriptor format for TX: "
352 "out %d, int %d\n", out, in);
353 break;
355 /* Skip header. TODO: support TSO. */
356 len = iov_length(vq->iov, out);
357 iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len);
358 iov_iter_advance(&msg.msg_iter, hdr_size);
359 /* Sanity check */
360 if (!msg_data_left(&msg)) {
361 vq_err(vq, "Unexpected header len for TX: "
362 "%zd expected %zd\n",
363 len, hdr_size);
364 break;
366 len = msg_data_left(&msg);
368 zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN
369 && (nvq->upend_idx + 1) % UIO_MAXIOV !=
370 nvq->done_idx
371 && vhost_net_tx_select_zcopy(net);
373 /* use msg_control to pass vhost zerocopy ubuf info to skb */
374 if (zcopy_used) {
375 struct ubuf_info *ubuf;
376 ubuf = nvq->ubuf_info + nvq->upend_idx;
378 vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head);
379 vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
380 ubuf->callback = vhost_zerocopy_callback;
381 ubuf->ctx = nvq->ubufs;
382 ubuf->desc = nvq->upend_idx;
383 msg.msg_control = ubuf;
384 msg.msg_controllen = sizeof(ubuf);
385 ubufs = nvq->ubufs;
386 atomic_inc(&ubufs->refcount);
387 nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
388 } else {
389 msg.msg_control = NULL;
390 ubufs = NULL;
392 /* TODO: Check specific error and bomb out unless ENOBUFS? */
393 err = sock->ops->sendmsg(sock, &msg, len);
394 if (unlikely(err < 0)) {
395 if (zcopy_used) {
396 vhost_net_ubuf_put(ubufs);
397 nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
398 % UIO_MAXIOV;
400 vhost_discard_vq_desc(vq, 1);
401 break;
403 if (err != len)
404 pr_debug("Truncated TX packet: "
405 " len %d != %zd\n", err, len);
406 if (!zcopy_used)
407 vhost_add_used_and_signal(&net->dev, vq, head, 0);
408 else
409 vhost_zerocopy_signal_used(net, vq);
410 total_len += len;
411 vhost_net_tx_packet(net);
412 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
413 vhost_poll_queue(&vq->poll);
414 break;
417 out:
418 mutex_unlock(&vq->mutex);
421 static int peek_head_len(struct sock *sk)
423 struct sk_buff *head;
424 int len = 0;
425 unsigned long flags;
427 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
428 head = skb_peek(&sk->sk_receive_queue);
429 if (likely(head)) {
430 len = head->len;
431 if (skb_vlan_tag_present(head))
432 len += VLAN_HLEN;
435 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
436 return len;
439 /* This is a multi-buffer version of vhost_get_desc, that works if
440 * vq has read descriptors only.
441 * @vq - the relevant virtqueue
442 * @datalen - data length we'll be reading
443 * @iovcount - returned count of io vectors we fill
444 * @log - vhost log
445 * @log_num - log offset
446 * @quota - headcount quota, 1 for big buffer
447 * returns number of buffer heads allocated, negative on error
449 static int get_rx_bufs(struct vhost_virtqueue *vq,
450 struct vring_used_elem *heads,
451 int datalen,
452 unsigned *iovcount,
453 struct vhost_log *log,
454 unsigned *log_num,
455 unsigned int quota)
457 unsigned int out, in;
458 int seg = 0;
459 int headcount = 0;
460 unsigned d;
461 int r, nlogs = 0;
462 /* len is always initialized before use since we are always called with
463 * datalen > 0.
465 u32 uninitialized_var(len);
467 while (datalen > 0 && headcount < quota) {
468 if (unlikely(seg >= UIO_MAXIOV)) {
469 r = -ENOBUFS;
470 goto err;
472 r = vhost_get_vq_desc(vq, vq->iov + seg,
473 ARRAY_SIZE(vq->iov) - seg, &out,
474 &in, log, log_num);
475 if (unlikely(r < 0))
476 goto err;
478 d = r;
479 if (d == vq->num) {
480 r = 0;
481 goto err;
483 if (unlikely(out || in <= 0)) {
484 vq_err(vq, "unexpected descriptor format for RX: "
485 "out %d, in %d\n", out, in);
486 r = -EINVAL;
487 goto err;
489 if (unlikely(log)) {
490 nlogs += *log_num;
491 log += *log_num;
493 heads[headcount].id = cpu_to_vhost32(vq, d);
494 len = iov_length(vq->iov + seg, in);
495 heads[headcount].len = cpu_to_vhost32(vq, len);
496 datalen -= len;
497 ++headcount;
498 seg += in;
500 heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen);
501 *iovcount = seg;
502 if (unlikely(log))
503 *log_num = nlogs;
505 /* Detect overrun */
506 if (unlikely(datalen > 0)) {
507 r = UIO_MAXIOV + 1;
508 goto err;
510 return headcount;
511 err:
512 vhost_discard_vq_desc(vq, headcount);
513 return r;
516 /* Expects to be always run from workqueue - which acts as
517 * read-size critical section for our kind of RCU. */
518 static void handle_rx(struct vhost_net *net)
520 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX];
521 struct vhost_virtqueue *vq = &nvq->vq;
522 unsigned uninitialized_var(in), log;
523 struct vhost_log *vq_log;
524 struct msghdr msg = {
525 .msg_name = NULL,
526 .msg_namelen = 0,
527 .msg_control = NULL, /* FIXME: get and handle RX aux data. */
528 .msg_controllen = 0,
529 .msg_flags = MSG_DONTWAIT,
531 struct virtio_net_hdr hdr = {
532 .flags = 0,
533 .gso_type = VIRTIO_NET_HDR_GSO_NONE
535 size_t total_len = 0;
536 int err, mergeable;
537 s16 headcount;
538 size_t vhost_hlen, sock_hlen;
539 size_t vhost_len, sock_len;
540 struct socket *sock;
541 struct iov_iter fixup;
542 __virtio16 num_buffers;
544 mutex_lock(&vq->mutex);
545 sock = vq->private_data;
546 if (!sock)
547 goto out;
548 vhost_disable_notify(&net->dev, vq);
550 vhost_hlen = nvq->vhost_hlen;
551 sock_hlen = nvq->sock_hlen;
553 vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ?
554 vq->log : NULL;
555 mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
557 while ((sock_len = peek_head_len(sock->sk))) {
558 sock_len += sock_hlen;
559 vhost_len = sock_len + vhost_hlen;
560 headcount = get_rx_bufs(vq, vq->heads, vhost_len,
561 &in, vq_log, &log,
562 likely(mergeable) ? UIO_MAXIOV : 1);
563 /* On error, stop handling until the next kick. */
564 if (unlikely(headcount < 0))
565 break;
566 /* On overrun, truncate and discard */
567 if (unlikely(headcount > UIO_MAXIOV)) {
568 iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1);
569 err = sock->ops->recvmsg(sock, &msg,
570 1, MSG_DONTWAIT | MSG_TRUNC);
571 pr_debug("Discarded rx packet: len %zd\n", sock_len);
572 continue;
574 /* OK, now we need to know about added descriptors. */
575 if (!headcount) {
576 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
577 /* They have slipped one in as we were
578 * doing that: check again. */
579 vhost_disable_notify(&net->dev, vq);
580 continue;
582 /* Nothing new? Wait for eventfd to tell us
583 * they refilled. */
584 break;
586 /* We don't need to be notified again. */
587 iov_iter_init(&msg.msg_iter, READ, vq->iov, in, vhost_len);
588 fixup = msg.msg_iter;
589 if (unlikely((vhost_hlen))) {
590 /* We will supply the header ourselves
591 * TODO: support TSO.
593 iov_iter_advance(&msg.msg_iter, vhost_hlen);
595 err = sock->ops->recvmsg(sock, &msg,
596 sock_len, MSG_DONTWAIT | MSG_TRUNC);
597 /* Userspace might have consumed the packet meanwhile:
598 * it's not supposed to do this usually, but might be hard
599 * to prevent. Discard data we got (if any) and keep going. */
600 if (unlikely(err != sock_len)) {
601 pr_debug("Discarded rx packet: "
602 " len %d, expected %zd\n", err, sock_len);
603 vhost_discard_vq_desc(vq, headcount);
604 continue;
606 /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
607 if (unlikely(vhost_hlen)) {
608 if (copy_to_iter(&hdr, sizeof(hdr),
609 &fixup) != sizeof(hdr)) {
610 vq_err(vq, "Unable to write vnet_hdr "
611 "at addr %p\n", vq->iov->iov_base);
612 break;
614 } else {
615 /* Header came from socket; we'll need to patch
616 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF
618 iov_iter_advance(&fixup, sizeof(hdr));
620 /* TODO: Should check and handle checksum. */
622 num_buffers = cpu_to_vhost16(vq, headcount);
623 if (likely(mergeable) &&
624 copy_to_iter(&num_buffers, sizeof num_buffers,
625 &fixup) != sizeof num_buffers) {
626 vq_err(vq, "Failed num_buffers write");
627 vhost_discard_vq_desc(vq, headcount);
628 break;
630 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
631 headcount);
632 if (unlikely(vq_log))
633 vhost_log_write(vq, vq_log, log, vhost_len);
634 total_len += vhost_len;
635 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
636 vhost_poll_queue(&vq->poll);
637 break;
640 out:
641 mutex_unlock(&vq->mutex);
644 static void handle_tx_kick(struct vhost_work *work)
646 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
647 poll.work);
648 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
650 handle_tx(net);
653 static void handle_rx_kick(struct vhost_work *work)
655 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
656 poll.work);
657 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
659 handle_rx(net);
662 static void handle_tx_net(struct vhost_work *work)
664 struct vhost_net *net = container_of(work, struct vhost_net,
665 poll[VHOST_NET_VQ_TX].work);
666 handle_tx(net);
669 static void handle_rx_net(struct vhost_work *work)
671 struct vhost_net *net = container_of(work, struct vhost_net,
672 poll[VHOST_NET_VQ_RX].work);
673 handle_rx(net);
676 static int vhost_net_open(struct inode *inode, struct file *f)
678 struct vhost_net *n;
679 struct vhost_dev *dev;
680 struct vhost_virtqueue **vqs;
681 int i;
683 n = kmalloc(sizeof *n, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
684 if (!n) {
685 n = vmalloc(sizeof *n);
686 if (!n)
687 return -ENOMEM;
689 vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
690 if (!vqs) {
691 kvfree(n);
692 return -ENOMEM;
695 dev = &n->dev;
696 vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq;
697 vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq;
698 n->vqs[VHOST_NET_VQ_TX].vq.handle_kick = handle_tx_kick;
699 n->vqs[VHOST_NET_VQ_RX].vq.handle_kick = handle_rx_kick;
700 for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
701 n->vqs[i].ubufs = NULL;
702 n->vqs[i].ubuf_info = NULL;
703 n->vqs[i].upend_idx = 0;
704 n->vqs[i].done_idx = 0;
705 n->vqs[i].vhost_hlen = 0;
706 n->vqs[i].sock_hlen = 0;
708 vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);
710 vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
711 vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
713 f->private_data = n;
715 return 0;
718 static void vhost_net_disable_vq(struct vhost_net *n,
719 struct vhost_virtqueue *vq)
721 struct vhost_net_virtqueue *nvq =
722 container_of(vq, struct vhost_net_virtqueue, vq);
723 struct vhost_poll *poll = n->poll + (nvq - n->vqs);
724 if (!vq->private_data)
725 return;
726 vhost_poll_stop(poll);
729 static int vhost_net_enable_vq(struct vhost_net *n,
730 struct vhost_virtqueue *vq)
732 struct vhost_net_virtqueue *nvq =
733 container_of(vq, struct vhost_net_virtqueue, vq);
734 struct vhost_poll *poll = n->poll + (nvq - n->vqs);
735 struct socket *sock;
737 sock = vq->private_data;
738 if (!sock)
739 return 0;
741 return vhost_poll_start(poll, sock->file);
744 static struct socket *vhost_net_stop_vq(struct vhost_net *n,
745 struct vhost_virtqueue *vq)
747 struct socket *sock;
749 mutex_lock(&vq->mutex);
750 sock = vq->private_data;
751 vhost_net_disable_vq(n, vq);
752 vq->private_data = NULL;
753 mutex_unlock(&vq->mutex);
754 return sock;
757 static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
758 struct socket **rx_sock)
760 *tx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_TX].vq);
761 *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq);
764 static void vhost_net_flush_vq(struct vhost_net *n, int index)
766 vhost_poll_flush(n->poll + index);
767 vhost_poll_flush(&n->vqs[index].vq.poll);
770 static void vhost_net_flush(struct vhost_net *n)
772 vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
773 vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
774 if (n->vqs[VHOST_NET_VQ_TX].ubufs) {
775 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
776 n->tx_flush = true;
777 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
778 /* Wait for all lower device DMAs done. */
779 vhost_net_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs);
780 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
781 n->tx_flush = false;
782 atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1);
783 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
787 static int vhost_net_release(struct inode *inode, struct file *f)
789 struct vhost_net *n = f->private_data;
790 struct socket *tx_sock;
791 struct socket *rx_sock;
793 vhost_net_stop(n, &tx_sock, &rx_sock);
794 vhost_net_flush(n);
795 vhost_dev_stop(&n->dev);
796 vhost_dev_cleanup(&n->dev, false);
797 vhost_net_vq_reset(n);
798 if (tx_sock)
799 sockfd_put(tx_sock);
800 if (rx_sock)
801 sockfd_put(rx_sock);
802 /* Make sure no callbacks are outstanding */
803 synchronize_rcu_bh();
804 /* We do an extra flush before freeing memory,
805 * since jobs can re-queue themselves. */
806 vhost_net_flush(n);
807 kfree(n->dev.vqs);
808 kvfree(n);
809 return 0;
812 static struct socket *get_raw_socket(int fd)
814 struct {
815 struct sockaddr_ll sa;
816 char buf[MAX_ADDR_LEN];
817 } uaddr;
818 int uaddr_len = sizeof uaddr, r;
819 struct socket *sock = sockfd_lookup(fd, &r);
821 if (!sock)
822 return ERR_PTR(-ENOTSOCK);
824 /* Parameter checking */
825 if (sock->sk->sk_type != SOCK_RAW) {
826 r = -ESOCKTNOSUPPORT;
827 goto err;
830 r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
831 &uaddr_len, 0);
832 if (r)
833 goto err;
835 if (uaddr.sa.sll_family != AF_PACKET) {
836 r = -EPFNOSUPPORT;
837 goto err;
839 return sock;
840 err:
841 sockfd_put(sock);
842 return ERR_PTR(r);
845 static struct socket *get_tap_socket(int fd)
847 struct file *file = fget(fd);
848 struct socket *sock;
850 if (!file)
851 return ERR_PTR(-EBADF);
852 sock = tun_get_socket(file);
853 if (!IS_ERR(sock))
854 return sock;
855 sock = macvtap_get_socket(file);
856 if (IS_ERR(sock))
857 fput(file);
858 return sock;
861 static struct socket *get_socket(int fd)
863 struct socket *sock;
865 /* special case to disable backend */
866 if (fd == -1)
867 return NULL;
868 sock = get_raw_socket(fd);
869 if (!IS_ERR(sock))
870 return sock;
871 sock = get_tap_socket(fd);
872 if (!IS_ERR(sock))
873 return sock;
874 return ERR_PTR(-ENOTSOCK);
877 static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
879 struct socket *sock, *oldsock;
880 struct vhost_virtqueue *vq;
881 struct vhost_net_virtqueue *nvq;
882 struct vhost_net_ubuf_ref *ubufs, *oldubufs = NULL;
883 int r;
885 mutex_lock(&n->dev.mutex);
886 r = vhost_dev_check_owner(&n->dev);
887 if (r)
888 goto err;
890 if (index >= VHOST_NET_VQ_MAX) {
891 r = -ENOBUFS;
892 goto err;
894 vq = &n->vqs[index].vq;
895 nvq = &n->vqs[index];
896 mutex_lock(&vq->mutex);
898 /* Verify that ring has been setup correctly. */
899 if (!vhost_vq_access_ok(vq)) {
900 r = -EFAULT;
901 goto err_vq;
903 sock = get_socket(fd);
904 if (IS_ERR(sock)) {
905 r = PTR_ERR(sock);
906 goto err_vq;
909 /* start polling new socket */
910 oldsock = vq->private_data;
911 if (sock != oldsock) {
912 ubufs = vhost_net_ubuf_alloc(vq,
913 sock && vhost_sock_zcopy(sock));
914 if (IS_ERR(ubufs)) {
915 r = PTR_ERR(ubufs);
916 goto err_ubufs;
919 vhost_net_disable_vq(n, vq);
920 vq->private_data = sock;
921 r = vhost_init_used(vq);
922 if (r)
923 goto err_used;
924 r = vhost_net_enable_vq(n, vq);
925 if (r)
926 goto err_used;
928 oldubufs = nvq->ubufs;
929 nvq->ubufs = ubufs;
931 n->tx_packets = 0;
932 n->tx_zcopy_err = 0;
933 n->tx_flush = false;
936 mutex_unlock(&vq->mutex);
938 if (oldubufs) {
939 vhost_net_ubuf_put_wait_and_free(oldubufs);
940 mutex_lock(&vq->mutex);
941 vhost_zerocopy_signal_used(n, vq);
942 mutex_unlock(&vq->mutex);
945 if (oldsock) {
946 vhost_net_flush_vq(n, index);
947 sockfd_put(oldsock);
950 mutex_unlock(&n->dev.mutex);
951 return 0;
953 err_used:
954 vq->private_data = oldsock;
955 vhost_net_enable_vq(n, vq);
956 if (ubufs)
957 vhost_net_ubuf_put_wait_and_free(ubufs);
958 err_ubufs:
959 sockfd_put(sock);
960 err_vq:
961 mutex_unlock(&vq->mutex);
962 err:
963 mutex_unlock(&n->dev.mutex);
964 return r;
967 static long vhost_net_reset_owner(struct vhost_net *n)
969 struct socket *tx_sock = NULL;
970 struct socket *rx_sock = NULL;
971 long err;
972 struct vhost_memory *memory;
974 mutex_lock(&n->dev.mutex);
975 err = vhost_dev_check_owner(&n->dev);
976 if (err)
977 goto done;
978 memory = vhost_dev_reset_owner_prepare();
979 if (!memory) {
980 err = -ENOMEM;
981 goto done;
983 vhost_net_stop(n, &tx_sock, &rx_sock);
984 vhost_net_flush(n);
985 vhost_dev_reset_owner(&n->dev, memory);
986 vhost_net_vq_reset(n);
987 done:
988 mutex_unlock(&n->dev.mutex);
989 if (tx_sock)
990 sockfd_put(tx_sock);
991 if (rx_sock)
992 sockfd_put(rx_sock);
993 return err;
996 static int vhost_net_set_features(struct vhost_net *n, u64 features)
998 size_t vhost_hlen, sock_hlen, hdr_len;
999 int i;
1001 hdr_len = (features & ((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
1002 (1ULL << VIRTIO_F_VERSION_1))) ?
1003 sizeof(struct virtio_net_hdr_mrg_rxbuf) :
1004 sizeof(struct virtio_net_hdr);
1005 if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
1006 /* vhost provides vnet_hdr */
1007 vhost_hlen = hdr_len;
1008 sock_hlen = 0;
1009 } else {
1010 /* socket provides vnet_hdr */
1011 vhost_hlen = 0;
1012 sock_hlen = hdr_len;
1014 mutex_lock(&n->dev.mutex);
1015 if ((features & (1 << VHOST_F_LOG_ALL)) &&
1016 !vhost_log_access_ok(&n->dev)) {
1017 mutex_unlock(&n->dev.mutex);
1018 return -EFAULT;
1020 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
1021 mutex_lock(&n->vqs[i].vq.mutex);
1022 n->vqs[i].vq.acked_features = features;
1023 n->vqs[i].vhost_hlen = vhost_hlen;
1024 n->vqs[i].sock_hlen = sock_hlen;
1025 mutex_unlock(&n->vqs[i].vq.mutex);
1027 mutex_unlock(&n->dev.mutex);
1028 return 0;
1031 static long vhost_net_set_owner(struct vhost_net *n)
1033 int r;
1035 mutex_lock(&n->dev.mutex);
1036 if (vhost_dev_has_owner(&n->dev)) {
1037 r = -EBUSY;
1038 goto out;
1040 r = vhost_net_set_ubuf_info(n);
1041 if (r)
1042 goto out;
1043 r = vhost_dev_set_owner(&n->dev);
1044 if (r)
1045 vhost_net_clear_ubuf_info(n);
1046 vhost_net_flush(n);
1047 out:
1048 mutex_unlock(&n->dev.mutex);
1049 return r;
1052 static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
1053 unsigned long arg)
1055 struct vhost_net *n = f->private_data;
1056 void __user *argp = (void __user *)arg;
1057 u64 __user *featurep = argp;
1058 struct vhost_vring_file backend;
1059 u64 features;
1060 int r;
1062 switch (ioctl) {
1063 case VHOST_NET_SET_BACKEND:
1064 if (copy_from_user(&backend, argp, sizeof backend))
1065 return -EFAULT;
1066 return vhost_net_set_backend(n, backend.index, backend.fd);
1067 case VHOST_GET_FEATURES:
1068 features = VHOST_NET_FEATURES;
1069 if (copy_to_user(featurep, &features, sizeof features))
1070 return -EFAULT;
1071 return 0;
1072 case VHOST_SET_FEATURES:
1073 if (copy_from_user(&features, featurep, sizeof features))
1074 return -EFAULT;
1075 if (features & ~VHOST_NET_FEATURES)
1076 return -EOPNOTSUPP;
1077 return vhost_net_set_features(n, features);
1078 case VHOST_RESET_OWNER:
1079 return vhost_net_reset_owner(n);
1080 case VHOST_SET_OWNER:
1081 return vhost_net_set_owner(n);
1082 default:
1083 mutex_lock(&n->dev.mutex);
1084 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
1085 if (r == -ENOIOCTLCMD)
1086 r = vhost_vring_ioctl(&n->dev, ioctl, argp);
1087 else
1088 vhost_net_flush(n);
1089 mutex_unlock(&n->dev.mutex);
1090 return r;
1094 #ifdef CONFIG_COMPAT
1095 static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
1096 unsigned long arg)
1098 return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1100 #endif
1102 static const struct file_operations vhost_net_fops = {
1103 .owner = THIS_MODULE,
1104 .release = vhost_net_release,
1105 .unlocked_ioctl = vhost_net_ioctl,
1106 #ifdef CONFIG_COMPAT
1107 .compat_ioctl = vhost_net_compat_ioctl,
1108 #endif
1109 .open = vhost_net_open,
1110 .llseek = noop_llseek,
1113 static struct miscdevice vhost_net_misc = {
1114 .minor = VHOST_NET_MINOR,
1115 .name = "vhost-net",
1116 .fops = &vhost_net_fops,
1119 static int vhost_net_init(void)
1121 if (experimental_zcopytx)
1122 vhost_net_enable_zcopy(VHOST_NET_VQ_TX);
1123 return misc_register(&vhost_net_misc);
1125 module_init(vhost_net_init);
1127 static void vhost_net_exit(void)
1129 misc_deregister(&vhost_net_misc);
1131 module_exit(vhost_net_exit);
1133 MODULE_VERSION("0.0.1");
1134 MODULE_LICENSE("GPL v2");
1135 MODULE_AUTHOR("Michael S. Tsirkin");
1136 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1137 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
1138 MODULE_ALIAS("devname:vhost-net");