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.
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>
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)
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)
62 VHOST_NET_FEATURES = VHOST_FEATURES |
63 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
64 (1ULL << VIRTIO_NET_F_MRG_RXBUF)
73 struct vhost_net_ubuf_ref {
74 /* refcount follows semantics similar to kref:
75 * 0: object is released
76 * 1: no outstanding ubufs
77 * >1: outstanding ubufs
80 wait_queue_head_t wait;
81 struct vhost_virtqueue *vq;
84 struct vhost_net_virtqueue {
85 struct vhost_virtqueue vq;
88 /* vhost zerocopy support fields below: */
89 /* last used idx for outstanding DMA zerocopy buffers */
91 /* first used idx for DMA done zerocopy buffers */
93 /* an array of userspace buffers info */
94 struct ubuf_info *ubuf_info;
95 /* Reference counting for outstanding ubufs.
96 * Protected by vq mutex. Writers must also take device mutex. */
97 struct vhost_net_ubuf_ref *ubufs;
101 struct vhost_dev dev;
102 struct vhost_net_virtqueue vqs[VHOST_NET_VQ_MAX];
103 struct vhost_poll poll[VHOST_NET_VQ_MAX];
104 /* Number of TX recently submitted.
105 * Protected by tx vq lock. */
107 /* Number of times zerocopy TX recently failed.
108 * Protected by tx vq lock. */
109 unsigned tx_zcopy_err;
110 /* Flush in progress. Protected by tx vq lock. */
114 static unsigned vhost_net_zcopy_mask __read_mostly;
116 static void vhost_net_enable_zcopy(int vq)
118 vhost_net_zcopy_mask |= 0x1 << vq;
121 static struct vhost_net_ubuf_ref *
122 vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy)
124 struct vhost_net_ubuf_ref *ubufs;
125 /* No zero copy backend? Nothing to count. */
128 ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL);
130 return ERR_PTR(-ENOMEM);
131 atomic_set(&ubufs->refcount, 1);
132 init_waitqueue_head(&ubufs->wait);
137 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
139 int r = atomic_sub_return(1, &ubufs->refcount);
141 wake_up(&ubufs->wait);
145 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs)
147 vhost_net_ubuf_put(ubufs);
148 wait_event(ubufs->wait, !atomic_read(&ubufs->refcount));
151 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs)
153 vhost_net_ubuf_put_and_wait(ubufs);
157 static void vhost_net_clear_ubuf_info(struct vhost_net *n)
161 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
162 kfree(n->vqs[i].ubuf_info);
163 n->vqs[i].ubuf_info = NULL;
167 static int vhost_net_set_ubuf_info(struct vhost_net *n)
172 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
173 zcopy = vhost_net_zcopy_mask & (0x1 << i);
176 n->vqs[i].ubuf_info = kmalloc(sizeof(*n->vqs[i].ubuf_info) *
177 UIO_MAXIOV, GFP_KERNEL);
178 if (!n->vqs[i].ubuf_info)
184 vhost_net_clear_ubuf_info(n);
188 static void vhost_net_vq_reset(struct vhost_net *n)
192 vhost_net_clear_ubuf_info(n);
194 for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
195 n->vqs[i].done_idx = 0;
196 n->vqs[i].upend_idx = 0;
197 n->vqs[i].ubufs = NULL;
198 n->vqs[i].vhost_hlen = 0;
199 n->vqs[i].sock_hlen = 0;
204 static void vhost_net_tx_packet(struct vhost_net *net)
207 if (net->tx_packets < 1024)
210 net->tx_zcopy_err = 0;
213 static void vhost_net_tx_err(struct vhost_net *net)
218 static bool vhost_net_tx_select_zcopy(struct vhost_net *net)
220 /* TX flush waits for outstanding DMAs to be done.
221 * Don't start new DMAs.
223 return !net->tx_flush &&
224 net->tx_packets / 64 >= net->tx_zcopy_err;
227 static bool vhost_sock_zcopy(struct socket *sock)
229 return unlikely(experimental_zcopytx) &&
230 sock_flag(sock->sk, SOCK_ZEROCOPY);
233 /* In case of DMA done not in order in lower device driver for some reason.
234 * upend_idx is used to track end of used idx, done_idx is used to track head
235 * of used idx. Once lower device DMA done contiguously, we will signal KVM
238 static void vhost_zerocopy_signal_used(struct vhost_net *net,
239 struct vhost_virtqueue *vq)
241 struct vhost_net_virtqueue *nvq =
242 container_of(vq, struct vhost_net_virtqueue, vq);
246 for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
247 if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
248 vhost_net_tx_err(net);
249 if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
250 vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
256 add = min(UIO_MAXIOV - nvq->done_idx, j);
257 vhost_add_used_and_signal_n(vq->dev, vq,
258 &vq->heads[nvq->done_idx], add);
259 nvq->done_idx = (nvq->done_idx + add) % UIO_MAXIOV;
264 static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success)
266 struct vhost_net_ubuf_ref *ubufs = ubuf->ctx;
267 struct vhost_virtqueue *vq = ubufs->vq;
272 /* set len to mark this desc buffers done DMA */
273 vq->heads[ubuf->desc].len = success ?
274 VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;
275 cnt = vhost_net_ubuf_put(ubufs);
278 * Trigger polling thread if guest stopped submitting new buffers:
279 * in this case, the refcount after decrement will eventually reach 1.
280 * We also trigger polling periodically after each 16 packets
281 * (the value 16 here is more or less arbitrary, it's tuned to trigger
282 * less than 10% of times).
284 if (cnt <= 1 || !(cnt % 16))
285 vhost_poll_queue(&vq->poll);
287 rcu_read_unlock_bh();
290 static inline unsigned long busy_clock(void)
292 return local_clock() >> 10;
295 static bool vhost_can_busy_poll(struct vhost_dev *dev,
296 unsigned long endtime)
298 return likely(!need_resched()) &&
299 likely(!time_after(busy_clock(), endtime)) &&
300 likely(!signal_pending(current)) &&
301 !vhost_has_work(dev);
304 static void vhost_net_disable_vq(struct vhost_net *n,
305 struct vhost_virtqueue *vq)
307 struct vhost_net_virtqueue *nvq =
308 container_of(vq, struct vhost_net_virtqueue, vq);
309 struct vhost_poll *poll = n->poll + (nvq - n->vqs);
310 if (!vq->private_data)
312 vhost_poll_stop(poll);
315 static int vhost_net_enable_vq(struct vhost_net *n,
316 struct vhost_virtqueue *vq)
318 struct vhost_net_virtqueue *nvq =
319 container_of(vq, struct vhost_net_virtqueue, vq);
320 struct vhost_poll *poll = n->poll + (nvq - n->vqs);
323 sock = vq->private_data;
327 return vhost_poll_start(poll, sock->file);
330 static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
331 struct vhost_virtqueue *vq,
332 struct iovec iov[], unsigned int iov_size,
333 unsigned int *out_num, unsigned int *in_num)
335 unsigned long uninitialized_var(endtime);
336 int r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
337 out_num, in_num, NULL, NULL);
339 if (r == vq->num && vq->busyloop_timeout) {
341 endtime = busy_clock() + vq->busyloop_timeout;
342 while (vhost_can_busy_poll(vq->dev, endtime) &&
343 vhost_vq_avail_empty(vq->dev, vq))
344 cpu_relax_lowlatency();
346 r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
347 out_num, in_num, NULL, NULL);
353 /* Expects to be always run from workqueue - which acts as
354 * read-size critical section for our kind of RCU. */
355 static void handle_tx(struct vhost_net *net)
357 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
358 struct vhost_virtqueue *vq = &nvq->vq;
361 struct msghdr msg = {
366 .msg_flags = MSG_DONTWAIT,
368 size_t len, total_len = 0;
372 struct vhost_net_ubuf_ref *uninitialized_var(ubufs);
373 bool zcopy, zcopy_used;
375 mutex_lock(&vq->mutex);
376 sock = vq->private_data;
380 vhost_disable_notify(&net->dev, vq);
382 hdr_size = nvq->vhost_hlen;
386 /* Release DMAs done buffers first */
388 vhost_zerocopy_signal_used(net, vq);
390 /* If more outstanding DMAs, queue the work.
391 * Handle upend_idx wrap around
393 if (unlikely((nvq->upend_idx + vq->num - VHOST_MAX_PEND)
394 % UIO_MAXIOV == nvq->done_idx))
397 head = vhost_net_tx_get_vq_desc(net, vq, vq->iov,
400 /* On error, stop handling until the next kick. */
401 if (unlikely(head < 0))
403 /* Nothing new? Wait for eventfd to tell us they refilled. */
404 if (head == vq->num) {
405 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
406 vhost_disable_notify(&net->dev, vq);
412 vq_err(vq, "Unexpected descriptor format for TX: "
413 "out %d, int %d\n", out, in);
416 /* Skip header. TODO: support TSO. */
417 len = iov_length(vq->iov, out);
418 iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len);
419 iov_iter_advance(&msg.msg_iter, hdr_size);
421 if (!msg_data_left(&msg)) {
422 vq_err(vq, "Unexpected header len for TX: "
423 "%zd expected %zd\n",
427 len = msg_data_left(&msg);
429 zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN
430 && (nvq->upend_idx + 1) % UIO_MAXIOV !=
432 && vhost_net_tx_select_zcopy(net);
434 /* use msg_control to pass vhost zerocopy ubuf info to skb */
436 struct ubuf_info *ubuf;
437 ubuf = nvq->ubuf_info + nvq->upend_idx;
439 vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head);
440 vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
441 ubuf->callback = vhost_zerocopy_callback;
442 ubuf->ctx = nvq->ubufs;
443 ubuf->desc = nvq->upend_idx;
444 msg.msg_control = ubuf;
445 msg.msg_controllen = sizeof(ubuf);
447 atomic_inc(&ubufs->refcount);
448 nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
450 msg.msg_control = NULL;
453 /* TODO: Check specific error and bomb out unless ENOBUFS? */
454 err = sock->ops->sendmsg(sock, &msg, len);
455 if (unlikely(err < 0)) {
457 vhost_net_ubuf_put(ubufs);
458 nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
461 vhost_discard_vq_desc(vq, 1);
465 pr_debug("Truncated TX packet: "
466 " len %d != %zd\n", err, len);
468 vhost_add_used_and_signal(&net->dev, vq, head, 0);
470 vhost_zerocopy_signal_used(net, vq);
472 vhost_net_tx_packet(net);
473 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
474 vhost_poll_queue(&vq->poll);
479 mutex_unlock(&vq->mutex);
482 static int peek_head_len(struct sock *sk)
484 struct socket *sock = sk->sk_socket;
485 struct sk_buff *head;
489 if (sock->ops->peek_len)
490 return sock->ops->peek_len(sock);
492 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
493 head = skb_peek(&sk->sk_receive_queue);
496 if (skb_vlan_tag_present(head))
500 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
504 static int sk_has_rx_data(struct sock *sk)
506 struct socket *sock = sk->sk_socket;
508 if (sock->ops->peek_len)
509 return sock->ops->peek_len(sock);
511 return skb_queue_empty(&sk->sk_receive_queue);
514 static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk)
516 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
517 struct vhost_virtqueue *vq = &nvq->vq;
518 unsigned long uninitialized_var(endtime);
519 int len = peek_head_len(sk);
521 if (!len && vq->busyloop_timeout) {
522 /* Both tx vq and rx socket were polled here */
523 mutex_lock(&vq->mutex);
524 vhost_disable_notify(&net->dev, vq);
527 endtime = busy_clock() + vq->busyloop_timeout;
529 while (vhost_can_busy_poll(&net->dev, endtime) &&
530 !sk_has_rx_data(sk) &&
531 vhost_vq_avail_empty(&net->dev, vq))
532 cpu_relax_lowlatency();
536 if (vhost_enable_notify(&net->dev, vq))
537 vhost_poll_queue(&vq->poll);
538 mutex_unlock(&vq->mutex);
540 len = peek_head_len(sk);
546 /* This is a multi-buffer version of vhost_get_desc, that works if
547 * vq has read descriptors only.
548 * @vq - the relevant virtqueue
549 * @datalen - data length we'll be reading
550 * @iovcount - returned count of io vectors we fill
552 * @log_num - log offset
553 * @quota - headcount quota, 1 for big buffer
554 * returns number of buffer heads allocated, negative on error
556 static int get_rx_bufs(struct vhost_virtqueue *vq,
557 struct vring_used_elem *heads,
560 struct vhost_log *log,
564 unsigned int out, in;
569 /* len is always initialized before use since we are always called with
572 u32 uninitialized_var(len);
574 while (datalen > 0 && headcount < quota) {
575 if (unlikely(seg >= UIO_MAXIOV)) {
579 r = vhost_get_vq_desc(vq, vq->iov + seg,
580 ARRAY_SIZE(vq->iov) - seg, &out,
590 if (unlikely(out || in <= 0)) {
591 vq_err(vq, "unexpected descriptor format for RX: "
592 "out %d, in %d\n", out, in);
600 heads[headcount].id = cpu_to_vhost32(vq, d);
601 len = iov_length(vq->iov + seg, in);
602 heads[headcount].len = cpu_to_vhost32(vq, len);
607 heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen);
613 if (unlikely(datalen > 0)) {
619 vhost_discard_vq_desc(vq, headcount);
623 /* Expects to be always run from workqueue - which acts as
624 * read-size critical section for our kind of RCU. */
625 static void handle_rx(struct vhost_net *net)
627 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX];
628 struct vhost_virtqueue *vq = &nvq->vq;
629 unsigned uninitialized_var(in), log;
630 struct vhost_log *vq_log;
631 struct msghdr msg = {
634 .msg_control = NULL, /* FIXME: get and handle RX aux data. */
636 .msg_flags = MSG_DONTWAIT,
638 struct virtio_net_hdr hdr = {
640 .gso_type = VIRTIO_NET_HDR_GSO_NONE
642 size_t total_len = 0;
645 size_t vhost_hlen, sock_hlen;
646 size_t vhost_len, sock_len;
648 struct iov_iter fixup;
649 __virtio16 num_buffers;
651 mutex_lock(&vq->mutex);
652 sock = vq->private_data;
655 vhost_disable_notify(&net->dev, vq);
656 vhost_net_disable_vq(net, vq);
658 vhost_hlen = nvq->vhost_hlen;
659 sock_hlen = nvq->sock_hlen;
661 vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ?
663 mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
665 while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk))) {
666 sock_len += sock_hlen;
667 vhost_len = sock_len + vhost_hlen;
668 headcount = get_rx_bufs(vq, vq->heads, vhost_len,
670 likely(mergeable) ? UIO_MAXIOV : 1);
671 /* On error, stop handling until the next kick. */
672 if (unlikely(headcount < 0))
674 /* On overrun, truncate and discard */
675 if (unlikely(headcount > UIO_MAXIOV)) {
676 iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1);
677 err = sock->ops->recvmsg(sock, &msg,
678 1, MSG_DONTWAIT | MSG_TRUNC);
679 pr_debug("Discarded rx packet: len %zd\n", sock_len);
682 /* OK, now we need to know about added descriptors. */
684 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
685 /* They have slipped one in as we were
686 * doing that: check again. */
687 vhost_disable_notify(&net->dev, vq);
690 /* Nothing new? Wait for eventfd to tell us
694 /* We don't need to be notified again. */
695 iov_iter_init(&msg.msg_iter, READ, vq->iov, in, vhost_len);
696 fixup = msg.msg_iter;
697 if (unlikely((vhost_hlen))) {
698 /* We will supply the header ourselves
701 iov_iter_advance(&msg.msg_iter, vhost_hlen);
703 err = sock->ops->recvmsg(sock, &msg,
704 sock_len, MSG_DONTWAIT | MSG_TRUNC);
705 /* Userspace might have consumed the packet meanwhile:
706 * it's not supposed to do this usually, but might be hard
707 * to prevent. Discard data we got (if any) and keep going. */
708 if (unlikely(err != sock_len)) {
709 pr_debug("Discarded rx packet: "
710 " len %d, expected %zd\n", err, sock_len);
711 vhost_discard_vq_desc(vq, headcount);
714 /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
715 if (unlikely(vhost_hlen)) {
716 if (copy_to_iter(&hdr, sizeof(hdr),
717 &fixup) != sizeof(hdr)) {
718 vq_err(vq, "Unable to write vnet_hdr "
719 "at addr %p\n", vq->iov->iov_base);
723 /* Header came from socket; we'll need to patch
724 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF
726 iov_iter_advance(&fixup, sizeof(hdr));
728 /* TODO: Should check and handle checksum. */
730 num_buffers = cpu_to_vhost16(vq, headcount);
731 if (likely(mergeable) &&
732 copy_to_iter(&num_buffers, sizeof num_buffers,
733 &fixup) != sizeof num_buffers) {
734 vq_err(vq, "Failed num_buffers write");
735 vhost_discard_vq_desc(vq, headcount);
738 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
740 if (unlikely(vq_log))
741 vhost_log_write(vq, vq_log, log, vhost_len);
742 total_len += vhost_len;
743 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
744 vhost_poll_queue(&vq->poll);
748 vhost_net_enable_vq(net, vq);
750 mutex_unlock(&vq->mutex);
753 static void handle_tx_kick(struct vhost_work *work)
755 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
757 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
762 static void handle_rx_kick(struct vhost_work *work)
764 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
766 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
771 static void handle_tx_net(struct vhost_work *work)
773 struct vhost_net *net = container_of(work, struct vhost_net,
774 poll[VHOST_NET_VQ_TX].work);
778 static void handle_rx_net(struct vhost_work *work)
780 struct vhost_net *net = container_of(work, struct vhost_net,
781 poll[VHOST_NET_VQ_RX].work);
785 static int vhost_net_open(struct inode *inode, struct file *f)
788 struct vhost_dev *dev;
789 struct vhost_virtqueue **vqs;
792 n = kmalloc(sizeof *n, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
794 n = vmalloc(sizeof *n);
798 vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
805 vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq;
806 vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq;
807 n->vqs[VHOST_NET_VQ_TX].vq.handle_kick = handle_tx_kick;
808 n->vqs[VHOST_NET_VQ_RX].vq.handle_kick = handle_rx_kick;
809 for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
810 n->vqs[i].ubufs = NULL;
811 n->vqs[i].ubuf_info = NULL;
812 n->vqs[i].upend_idx = 0;
813 n->vqs[i].done_idx = 0;
814 n->vqs[i].vhost_hlen = 0;
815 n->vqs[i].sock_hlen = 0;
817 vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);
819 vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
820 vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
827 static struct socket *vhost_net_stop_vq(struct vhost_net *n,
828 struct vhost_virtqueue *vq)
832 mutex_lock(&vq->mutex);
833 sock = vq->private_data;
834 vhost_net_disable_vq(n, vq);
835 vq->private_data = NULL;
836 mutex_unlock(&vq->mutex);
840 static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
841 struct socket **rx_sock)
843 *tx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_TX].vq);
844 *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq);
847 static void vhost_net_flush_vq(struct vhost_net *n, int index)
849 vhost_poll_flush(n->poll + index);
850 vhost_poll_flush(&n->vqs[index].vq.poll);
853 static void vhost_net_flush(struct vhost_net *n)
855 vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
856 vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
857 if (n->vqs[VHOST_NET_VQ_TX].ubufs) {
858 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
860 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
861 /* Wait for all lower device DMAs done. */
862 vhost_net_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs);
863 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
865 atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1);
866 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
870 static int vhost_net_release(struct inode *inode, struct file *f)
872 struct vhost_net *n = f->private_data;
873 struct socket *tx_sock;
874 struct socket *rx_sock;
876 vhost_net_stop(n, &tx_sock, &rx_sock);
878 vhost_dev_stop(&n->dev);
879 vhost_dev_cleanup(&n->dev, false);
880 vhost_net_vq_reset(n);
885 /* Make sure no callbacks are outstanding */
886 synchronize_rcu_bh();
887 /* We do an extra flush before freeing memory,
888 * since jobs can re-queue themselves. */
895 static struct socket *get_raw_socket(int fd)
898 struct sockaddr_ll sa;
899 char buf[MAX_ADDR_LEN];
901 int uaddr_len = sizeof uaddr, r;
902 struct socket *sock = sockfd_lookup(fd, &r);
905 return ERR_PTR(-ENOTSOCK);
907 /* Parameter checking */
908 if (sock->sk->sk_type != SOCK_RAW) {
909 r = -ESOCKTNOSUPPORT;
913 r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
918 if (uaddr.sa.sll_family != AF_PACKET) {
928 static struct socket *get_tap_socket(int fd)
930 struct file *file = fget(fd);
934 return ERR_PTR(-EBADF);
935 sock = tun_get_socket(file);
938 sock = macvtap_get_socket(file);
944 static struct socket *get_socket(int fd)
948 /* special case to disable backend */
951 sock = get_raw_socket(fd);
954 sock = get_tap_socket(fd);
957 return ERR_PTR(-ENOTSOCK);
960 static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
962 struct socket *sock, *oldsock;
963 struct vhost_virtqueue *vq;
964 struct vhost_net_virtqueue *nvq;
965 struct vhost_net_ubuf_ref *ubufs, *oldubufs = NULL;
968 mutex_lock(&n->dev.mutex);
969 r = vhost_dev_check_owner(&n->dev);
973 if (index >= VHOST_NET_VQ_MAX) {
977 vq = &n->vqs[index].vq;
978 nvq = &n->vqs[index];
979 mutex_lock(&vq->mutex);
981 /* Verify that ring has been setup correctly. */
982 if (!vhost_vq_access_ok(vq)) {
986 sock = get_socket(fd);
992 /* start polling new socket */
993 oldsock = vq->private_data;
994 if (sock != oldsock) {
995 ubufs = vhost_net_ubuf_alloc(vq,
996 sock && vhost_sock_zcopy(sock));
1002 vhost_net_disable_vq(n, vq);
1003 vq->private_data = sock;
1004 r = vhost_vq_init_access(vq);
1007 r = vhost_net_enable_vq(n, vq);
1011 oldubufs = nvq->ubufs;
1015 n->tx_zcopy_err = 0;
1016 n->tx_flush = false;
1019 mutex_unlock(&vq->mutex);
1022 vhost_net_ubuf_put_wait_and_free(oldubufs);
1023 mutex_lock(&vq->mutex);
1024 vhost_zerocopy_signal_used(n, vq);
1025 mutex_unlock(&vq->mutex);
1029 vhost_net_flush_vq(n, index);
1030 sockfd_put(oldsock);
1033 mutex_unlock(&n->dev.mutex);
1037 vq->private_data = oldsock;
1038 vhost_net_enable_vq(n, vq);
1040 vhost_net_ubuf_put_wait_and_free(ubufs);
1044 mutex_unlock(&vq->mutex);
1046 mutex_unlock(&n->dev.mutex);
1050 static long vhost_net_reset_owner(struct vhost_net *n)
1052 struct socket *tx_sock = NULL;
1053 struct socket *rx_sock = NULL;
1055 struct vhost_memory *memory;
1057 mutex_lock(&n->dev.mutex);
1058 err = vhost_dev_check_owner(&n->dev);
1061 memory = vhost_dev_reset_owner_prepare();
1066 vhost_net_stop(n, &tx_sock, &rx_sock);
1068 vhost_dev_reset_owner(&n->dev, memory);
1069 vhost_net_vq_reset(n);
1071 mutex_unlock(&n->dev.mutex);
1073 sockfd_put(tx_sock);
1075 sockfd_put(rx_sock);
1079 static int vhost_net_set_features(struct vhost_net *n, u64 features)
1081 size_t vhost_hlen, sock_hlen, hdr_len;
1084 hdr_len = (features & ((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
1085 (1ULL << VIRTIO_F_VERSION_1))) ?
1086 sizeof(struct virtio_net_hdr_mrg_rxbuf) :
1087 sizeof(struct virtio_net_hdr);
1088 if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
1089 /* vhost provides vnet_hdr */
1090 vhost_hlen = hdr_len;
1093 /* socket provides vnet_hdr */
1095 sock_hlen = hdr_len;
1097 mutex_lock(&n->dev.mutex);
1098 if ((features & (1 << VHOST_F_LOG_ALL)) &&
1099 !vhost_log_access_ok(&n->dev)) {
1100 mutex_unlock(&n->dev.mutex);
1103 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
1104 mutex_lock(&n->vqs[i].vq.mutex);
1105 n->vqs[i].vq.acked_features = features;
1106 n->vqs[i].vhost_hlen = vhost_hlen;
1107 n->vqs[i].sock_hlen = sock_hlen;
1108 mutex_unlock(&n->vqs[i].vq.mutex);
1110 mutex_unlock(&n->dev.mutex);
1114 static long vhost_net_set_owner(struct vhost_net *n)
1118 mutex_lock(&n->dev.mutex);
1119 if (vhost_dev_has_owner(&n->dev)) {
1123 r = vhost_net_set_ubuf_info(n);
1126 r = vhost_dev_set_owner(&n->dev);
1128 vhost_net_clear_ubuf_info(n);
1131 mutex_unlock(&n->dev.mutex);
1135 static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
1138 struct vhost_net *n = f->private_data;
1139 void __user *argp = (void __user *)arg;
1140 u64 __user *featurep = argp;
1141 struct vhost_vring_file backend;
1146 case VHOST_NET_SET_BACKEND:
1147 if (copy_from_user(&backend, argp, sizeof backend))
1149 return vhost_net_set_backend(n, backend.index, backend.fd);
1150 case VHOST_GET_FEATURES:
1151 features = VHOST_NET_FEATURES;
1152 if (copy_to_user(featurep, &features, sizeof features))
1155 case VHOST_SET_FEATURES:
1156 if (copy_from_user(&features, featurep, sizeof features))
1158 if (features & ~VHOST_NET_FEATURES)
1160 return vhost_net_set_features(n, features);
1161 case VHOST_RESET_OWNER:
1162 return vhost_net_reset_owner(n);
1163 case VHOST_SET_OWNER:
1164 return vhost_net_set_owner(n);
1166 mutex_lock(&n->dev.mutex);
1167 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
1168 if (r == -ENOIOCTLCMD)
1169 r = vhost_vring_ioctl(&n->dev, ioctl, argp);
1172 mutex_unlock(&n->dev.mutex);
1177 #ifdef CONFIG_COMPAT
1178 static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
1181 return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1185 static const struct file_operations vhost_net_fops = {
1186 .owner = THIS_MODULE,
1187 .release = vhost_net_release,
1188 .unlocked_ioctl = vhost_net_ioctl,
1189 #ifdef CONFIG_COMPAT
1190 .compat_ioctl = vhost_net_compat_ioctl,
1192 .open = vhost_net_open,
1193 .llseek = noop_llseek,
1196 static struct miscdevice vhost_net_misc = {
1197 .minor = VHOST_NET_MINOR,
1198 .name = "vhost-net",
1199 .fops = &vhost_net_fops,
1202 static int vhost_net_init(void)
1204 if (experimental_zcopytx)
1205 vhost_net_enable_zcopy(VHOST_NET_VQ_TX);
1206 return misc_register(&vhost_net_misc);
1208 module_init(vhost_net_init);
1210 static void vhost_net_exit(void)
1212 misc_deregister(&vhost_net_misc);
1214 module_exit(vhost_net_exit);
1216 MODULE_VERSION("0.0.1");
1217 MODULE_LICENSE("GPL v2");
1218 MODULE_AUTHOR("Michael S. Tsirkin");
1219 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1220 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
1221 MODULE_ALIAS("devname:vhost-net");