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/rcupdate.h>
19 #include <linux/file.h>
20 #include <linux/slab.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;
34 module_param(experimental_zcopytx, int, 0444);
35 MODULE_PARM_DESC(experimental_zcopytx, "Enable Experimental Zero Copy TX");
37 /* Max number of bytes transferred before requeueing the job.
38 * Using this limit prevents one virtqueue from starving others. */
39 #define VHOST_NET_WEIGHT 0x80000
41 /* MAX number of TX used buffers for outstanding zerocopy */
42 #define VHOST_MAX_PEND 128
43 #define VHOST_GOODCOPY_LEN 256
46 * For transmit, used buffer len is unused; we override it to track buffer
47 * status internally; used for zerocopy tx only.
49 /* Lower device DMA failed */
50 #define VHOST_DMA_FAILED_LEN 3
51 /* Lower device DMA done */
52 #define VHOST_DMA_DONE_LEN 2
53 /* Lower device DMA in progress */
54 #define VHOST_DMA_IN_PROGRESS 1
56 #define VHOST_DMA_CLEAR_LEN 0
58 #define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN)
66 enum vhost_net_poll_state {
67 VHOST_NET_POLL_DISABLED = 0,
68 VHOST_NET_POLL_STARTED = 1,
69 VHOST_NET_POLL_STOPPED = 2,
74 struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX];
75 struct vhost_poll poll[VHOST_NET_VQ_MAX];
76 /* Tells us whether we are polling a socket for TX.
77 * We only do this when socket buffer fills up.
78 * Protected by tx vq lock. */
79 enum vhost_net_poll_state tx_poll_state;
80 /* Number of TX recently submitted.
81 * Protected by tx vq lock. */
83 /* Number of times zerocopy TX recently failed.
84 * Protected by tx vq lock. */
85 unsigned tx_zcopy_err;
88 static void vhost_net_tx_packet(struct vhost_net *net)
91 if (net->tx_packets < 1024)
94 net->tx_zcopy_err = 0;
97 static void vhost_net_tx_err(struct vhost_net *net)
102 static bool vhost_net_tx_select_zcopy(struct vhost_net *net)
104 return net->tx_packets / 64 >= net->tx_zcopy_err;
107 static bool vhost_sock_zcopy(struct socket *sock)
109 return unlikely(experimental_zcopytx) &&
110 sock_flag(sock->sk, SOCK_ZEROCOPY);
113 /* Pop first len bytes from iovec. Return number of segments used. */
114 static int move_iovec_hdr(struct iovec *from, struct iovec *to,
115 size_t len, int iov_count)
120 while (len && seg < iov_count) {
121 size = min(from->iov_len, len);
122 to->iov_base = from->iov_base;
124 from->iov_len -= size;
125 from->iov_base += size;
133 /* Copy iovec entries for len bytes from iovec. */
134 static void copy_iovec_hdr(const struct iovec *from, struct iovec *to,
135 size_t len, int iovcount)
140 while (len && seg < iovcount) {
141 size = min(from->iov_len, len);
142 to->iov_base = from->iov_base;
151 /* Caller must have TX VQ lock */
152 static void tx_poll_stop(struct vhost_net *net)
154 if (likely(net->tx_poll_state != VHOST_NET_POLL_STARTED))
156 vhost_poll_stop(net->poll + VHOST_NET_VQ_TX);
157 net->tx_poll_state = VHOST_NET_POLL_STOPPED;
160 /* Caller must have TX VQ lock */
161 static void tx_poll_start(struct vhost_net *net, struct socket *sock)
163 if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED))
165 vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file);
166 net->tx_poll_state = VHOST_NET_POLL_STARTED;
169 /* In case of DMA done not in order in lower device driver for some reason.
170 * upend_idx is used to track end of used idx, done_idx is used to track head
171 * of used idx. Once lower device DMA done contiguously, we will signal KVM
174 static int vhost_zerocopy_signal_used(struct vhost_net *net,
175 struct vhost_virtqueue *vq)
180 for (i = vq->done_idx; i != vq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
181 if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
182 vhost_net_tx_err(net);
183 if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
184 vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
185 vhost_add_used_and_signal(vq->dev, vq,
196 static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success)
198 struct vhost_ubuf_ref *ubufs = ubuf->ctx;
199 struct vhost_virtqueue *vq = ubufs->vq;
200 int cnt = atomic_read(&ubufs->kref.refcount);
203 * Trigger polling thread if guest stopped submitting new buffers:
204 * in this case, the refcount after decrement will eventually reach 1
206 * We also trigger polling periodically after each 16 packets
207 * (the value 16 here is more or less arbitrary, it's tuned to trigger
208 * less than 10% of times).
210 if (cnt <= 2 || !(cnt % 16))
211 vhost_poll_queue(&vq->poll);
212 /* set len to mark this desc buffers done DMA */
213 vq->heads[ubuf->desc].len = success ?
214 VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;
215 vhost_ubuf_put(ubufs);
218 /* Expects to be always run from workqueue - which acts as
219 * read-size critical section for our kind of RCU. */
220 static void handle_tx(struct vhost_net *net)
222 struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
225 struct msghdr msg = {
231 .msg_flags = MSG_DONTWAIT,
233 size_t len, total_len = 0;
237 struct vhost_ubuf_ref *uninitialized_var(ubufs);
240 /* TODO: check that we are running from vhost_worker? */
241 sock = rcu_dereference_check(vq->private_data, 1);
245 wmem = atomic_read(&sock->sk->sk_wmem_alloc);
246 if (wmem >= sock->sk->sk_sndbuf) {
247 mutex_lock(&vq->mutex);
248 tx_poll_start(net, sock);
249 mutex_unlock(&vq->mutex);
253 mutex_lock(&vq->mutex);
254 vhost_disable_notify(&net->dev, vq);
256 if (wmem < sock->sk->sk_sndbuf / 2)
258 hdr_size = vq->vhost_hlen;
262 /* Release DMAs done buffers first */
264 vhost_zerocopy_signal_used(net, vq);
266 head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
270 /* On error, stop handling until the next kick. */
271 if (unlikely(head < 0))
273 /* Nothing new? Wait for eventfd to tell us they refilled. */
274 if (head == vq->num) {
277 wmem = atomic_read(&sock->sk->sk_wmem_alloc);
278 if (wmem >= sock->sk->sk_sndbuf * 3 / 4) {
279 tx_poll_start(net, sock);
280 set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
283 /* If more outstanding DMAs, queue the work.
284 * Handle upend_idx wrap around
286 num_pends = likely(vq->upend_idx >= vq->done_idx) ?
287 (vq->upend_idx - vq->done_idx) :
288 (vq->upend_idx + UIO_MAXIOV - vq->done_idx);
289 if (unlikely(num_pends > VHOST_MAX_PEND)) {
290 tx_poll_start(net, sock);
291 set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
294 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
295 vhost_disable_notify(&net->dev, vq);
301 vq_err(vq, "Unexpected descriptor format for TX: "
302 "out %d, int %d\n", out, in);
305 /* Skip header. TODO: support TSO. */
306 s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out);
307 msg.msg_iovlen = out;
308 len = iov_length(vq->iov, out);
311 vq_err(vq, "Unexpected header len for TX: "
312 "%zd expected %zd\n",
313 iov_length(vq->hdr, s), hdr_size);
316 /* use msg_control to pass vhost zerocopy ubuf info to skb */
318 vq->heads[vq->upend_idx].id = head;
319 if (!vhost_net_tx_select_zcopy(net) ||
320 len < VHOST_GOODCOPY_LEN) {
321 /* copy don't need to wait for DMA done */
322 vq->heads[vq->upend_idx].len =
324 msg.msg_control = NULL;
325 msg.msg_controllen = 0;
328 struct ubuf_info *ubuf = &vq->ubuf_info[head];
330 vq->heads[vq->upend_idx].len =
331 VHOST_DMA_IN_PROGRESS;
332 ubuf->callback = vhost_zerocopy_callback;
333 ubuf->ctx = vq->ubufs;
334 ubuf->desc = vq->upend_idx;
335 msg.msg_control = ubuf;
336 msg.msg_controllen = sizeof(ubuf);
338 kref_get(&ubufs->kref);
340 vq->upend_idx = (vq->upend_idx + 1) % UIO_MAXIOV;
342 /* TODO: Check specific error and bomb out unless ENOBUFS? */
343 err = sock->ops->sendmsg(NULL, sock, &msg, len);
344 if (unlikely(err < 0)) {
347 vhost_ubuf_put(ubufs);
348 vq->upend_idx = ((unsigned)vq->upend_idx - 1) %
351 vhost_discard_vq_desc(vq, 1);
352 if (err == -EAGAIN || err == -ENOBUFS)
353 tx_poll_start(net, sock);
357 pr_debug("Truncated TX packet: "
358 " len %d != %zd\n", err, len);
360 vhost_add_used_and_signal(&net->dev, vq, head, 0);
362 vhost_zerocopy_signal_used(net, vq);
364 vhost_net_tx_packet(net);
365 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
366 vhost_poll_queue(&vq->poll);
371 mutex_unlock(&vq->mutex);
374 static int peek_head_len(struct sock *sk)
376 struct sk_buff *head;
380 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
381 head = skb_peek(&sk->sk_receive_queue);
384 if (vlan_tx_tag_present(head))
388 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
392 /* This is a multi-buffer version of vhost_get_desc, that works if
393 * vq has read descriptors only.
394 * @vq - the relevant virtqueue
395 * @datalen - data length we'll be reading
396 * @iovcount - returned count of io vectors we fill
398 * @log_num - log offset
399 * @quota - headcount quota, 1 for big buffer
400 * returns number of buffer heads allocated, negative on error
402 static int get_rx_bufs(struct vhost_virtqueue *vq,
403 struct vring_used_elem *heads,
406 struct vhost_log *log,
410 unsigned int out, in;
416 while (datalen > 0 && headcount < quota) {
417 if (unlikely(seg >= UIO_MAXIOV)) {
421 d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
422 ARRAY_SIZE(vq->iov) - seg, &out,
428 if (unlikely(out || in <= 0)) {
429 vq_err(vq, "unexpected descriptor format for RX: "
430 "out %d, in %d\n", out, in);
438 heads[headcount].id = d;
439 heads[headcount].len = iov_length(vq->iov + seg, in);
440 datalen -= heads[headcount].len;
444 heads[headcount - 1].len += datalen;
450 vhost_discard_vq_desc(vq, headcount);
454 /* Expects to be always run from workqueue - which acts as
455 * read-size critical section for our kind of RCU. */
456 static void handle_rx(struct vhost_net *net)
458 struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
459 unsigned uninitialized_var(in), log;
460 struct vhost_log *vq_log;
461 struct msghdr msg = {
464 .msg_control = NULL, /* FIXME: get and handle RX aux data. */
467 .msg_flags = MSG_DONTWAIT,
469 struct virtio_net_hdr_mrg_rxbuf hdr = {
471 .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
473 size_t total_len = 0;
476 size_t vhost_hlen, sock_hlen;
477 size_t vhost_len, sock_len;
478 /* TODO: check that we are running from vhost_worker? */
479 struct socket *sock = rcu_dereference_check(vq->private_data, 1);
484 mutex_lock(&vq->mutex);
485 vhost_disable_notify(&net->dev, vq);
486 vhost_hlen = vq->vhost_hlen;
487 sock_hlen = vq->sock_hlen;
489 vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
491 mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);
493 while ((sock_len = peek_head_len(sock->sk))) {
494 sock_len += sock_hlen;
495 vhost_len = sock_len + vhost_hlen;
496 headcount = get_rx_bufs(vq, vq->heads, vhost_len,
498 likely(mergeable) ? UIO_MAXIOV : 1);
499 /* On error, stop handling until the next kick. */
500 if (unlikely(headcount < 0))
502 /* OK, now we need to know about added descriptors. */
504 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
505 /* They have slipped one in as we were
506 * doing that: check again. */
507 vhost_disable_notify(&net->dev, vq);
510 /* Nothing new? Wait for eventfd to tell us
514 /* We don't need to be notified again. */
515 if (unlikely((vhost_hlen)))
516 /* Skip header. TODO: support TSO. */
517 move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in);
519 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
520 * needed because recvmsg can modify msg_iov. */
521 copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in);
523 err = sock->ops->recvmsg(NULL, sock, &msg,
524 sock_len, MSG_DONTWAIT | MSG_TRUNC);
525 /* Userspace might have consumed the packet meanwhile:
526 * it's not supposed to do this usually, but might be hard
527 * to prevent. Discard data we got (if any) and keep going. */
528 if (unlikely(err != sock_len)) {
529 pr_debug("Discarded rx packet: "
530 " len %d, expected %zd\n", err, sock_len);
531 vhost_discard_vq_desc(vq, headcount);
534 if (unlikely(vhost_hlen) &&
535 memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0,
537 vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
541 /* TODO: Should check and handle checksum. */
542 if (likely(mergeable) &&
543 memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount,
544 offsetof(typeof(hdr), num_buffers),
545 sizeof hdr.num_buffers)) {
546 vq_err(vq, "Failed num_buffers write");
547 vhost_discard_vq_desc(vq, headcount);
550 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
552 if (unlikely(vq_log))
553 vhost_log_write(vq, vq_log, log, vhost_len);
554 total_len += vhost_len;
555 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
556 vhost_poll_queue(&vq->poll);
561 mutex_unlock(&vq->mutex);
564 static void handle_tx_kick(struct vhost_work *work)
566 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
568 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
573 static void handle_rx_kick(struct vhost_work *work)
575 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
577 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
582 static void handle_tx_net(struct vhost_work *work)
584 struct vhost_net *net = container_of(work, struct vhost_net,
585 poll[VHOST_NET_VQ_TX].work);
589 static void handle_rx_net(struct vhost_work *work)
591 struct vhost_net *net = container_of(work, struct vhost_net,
592 poll[VHOST_NET_VQ_RX].work);
596 static int vhost_net_open(struct inode *inode, struct file *f)
598 struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
599 struct vhost_dev *dev;
606 n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
607 n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
608 r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
614 vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
615 vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
616 n->tx_poll_state = VHOST_NET_POLL_DISABLED;
623 static void vhost_net_disable_vq(struct vhost_net *n,
624 struct vhost_virtqueue *vq)
626 if (!vq->private_data)
628 if (vq == n->vqs + VHOST_NET_VQ_TX) {
630 n->tx_poll_state = VHOST_NET_POLL_DISABLED;
632 vhost_poll_stop(n->poll + VHOST_NET_VQ_RX);
635 static void vhost_net_enable_vq(struct vhost_net *n,
636 struct vhost_virtqueue *vq)
640 sock = rcu_dereference_protected(vq->private_data,
641 lockdep_is_held(&vq->mutex));
644 if (vq == n->vqs + VHOST_NET_VQ_TX) {
645 n->tx_poll_state = VHOST_NET_POLL_STOPPED;
646 tx_poll_start(n, sock);
648 vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file);
651 static struct socket *vhost_net_stop_vq(struct vhost_net *n,
652 struct vhost_virtqueue *vq)
656 mutex_lock(&vq->mutex);
657 sock = rcu_dereference_protected(vq->private_data,
658 lockdep_is_held(&vq->mutex));
659 vhost_net_disable_vq(n, vq);
660 rcu_assign_pointer(vq->private_data, NULL);
661 mutex_unlock(&vq->mutex);
665 static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
666 struct socket **rx_sock)
668 *tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX);
669 *rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX);
672 static void vhost_net_flush_vq(struct vhost_net *n, int index)
674 vhost_poll_flush(n->poll + index);
675 vhost_poll_flush(&n->dev.vqs[index].poll);
678 static void vhost_net_flush(struct vhost_net *n)
680 vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
681 vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
684 static int vhost_net_release(struct inode *inode, struct file *f)
686 struct vhost_net *n = f->private_data;
687 struct socket *tx_sock;
688 struct socket *rx_sock;
691 vhost_net_stop(n, &tx_sock, &rx_sock);
693 vhost_dev_stop(&n->dev);
694 for (i = 0; i < n->dev.nvqs; ++i) {
695 /* Wait for all lower device DMAs done. */
696 if (n->dev.vqs[i].ubufs)
697 vhost_ubuf_put_and_wait(n->dev.vqs[i].ubufs);
699 vhost_zerocopy_signal_used(n, &n->dev.vqs[i]);
701 vhost_dev_cleanup(&n->dev, false);
706 /* We do an extra flush before freeing memory,
707 * since jobs can re-queue themselves. */
713 static struct socket *get_raw_socket(int fd)
716 struct sockaddr_ll sa;
717 char buf[MAX_ADDR_LEN];
719 int uaddr_len = sizeof uaddr, r;
720 struct socket *sock = sockfd_lookup(fd, &r);
723 return ERR_PTR(-ENOTSOCK);
725 /* Parameter checking */
726 if (sock->sk->sk_type != SOCK_RAW) {
727 r = -ESOCKTNOSUPPORT;
731 r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
736 if (uaddr.sa.sll_family != AF_PACKET) {
746 static struct socket *get_tap_socket(int fd)
748 struct file *file = fget(fd);
752 return ERR_PTR(-EBADF);
753 sock = tun_get_socket(file);
756 sock = macvtap_get_socket(file);
762 static struct socket *get_socket(int fd)
766 /* special case to disable backend */
769 sock = get_raw_socket(fd);
772 sock = get_tap_socket(fd);
775 return ERR_PTR(-ENOTSOCK);
778 static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
780 struct socket *sock, *oldsock;
781 struct vhost_virtqueue *vq;
782 struct vhost_ubuf_ref *ubufs, *oldubufs = NULL;
785 mutex_lock(&n->dev.mutex);
786 r = vhost_dev_check_owner(&n->dev);
790 if (index >= VHOST_NET_VQ_MAX) {
795 mutex_lock(&vq->mutex);
797 /* Verify that ring has been setup correctly. */
798 if (!vhost_vq_access_ok(vq)) {
802 sock = get_socket(fd);
808 /* start polling new socket */
809 oldsock = rcu_dereference_protected(vq->private_data,
810 lockdep_is_held(&vq->mutex));
811 if (sock != oldsock) {
812 ubufs = vhost_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock));
817 oldubufs = vq->ubufs;
819 vhost_net_disable_vq(n, vq);
820 rcu_assign_pointer(vq->private_data, sock);
821 vhost_net_enable_vq(n, vq);
823 r = vhost_init_used(vq);
831 mutex_unlock(&vq->mutex);
834 vhost_ubuf_put_and_wait(oldubufs);
835 mutex_lock(&vq->mutex);
836 vhost_zerocopy_signal_used(n, vq);
837 mutex_unlock(&vq->mutex);
841 vhost_net_flush_vq(n, index);
845 mutex_unlock(&n->dev.mutex);
851 mutex_unlock(&vq->mutex);
853 mutex_unlock(&n->dev.mutex);
857 static long vhost_net_reset_owner(struct vhost_net *n)
859 struct socket *tx_sock = NULL;
860 struct socket *rx_sock = NULL;
863 mutex_lock(&n->dev.mutex);
864 err = vhost_dev_check_owner(&n->dev);
867 vhost_net_stop(n, &tx_sock, &rx_sock);
869 err = vhost_dev_reset_owner(&n->dev);
871 mutex_unlock(&n->dev.mutex);
879 static int vhost_net_set_features(struct vhost_net *n, u64 features)
881 size_t vhost_hlen, sock_hlen, hdr_len;
884 hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
885 sizeof(struct virtio_net_hdr_mrg_rxbuf) :
886 sizeof(struct virtio_net_hdr);
887 if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
888 /* vhost provides vnet_hdr */
889 vhost_hlen = hdr_len;
892 /* socket provides vnet_hdr */
896 mutex_lock(&n->dev.mutex);
897 if ((features & (1 << VHOST_F_LOG_ALL)) &&
898 !vhost_log_access_ok(&n->dev)) {
899 mutex_unlock(&n->dev.mutex);
902 n->dev.acked_features = features;
904 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
905 mutex_lock(&n->vqs[i].mutex);
906 n->vqs[i].vhost_hlen = vhost_hlen;
907 n->vqs[i].sock_hlen = sock_hlen;
908 mutex_unlock(&n->vqs[i].mutex);
911 mutex_unlock(&n->dev.mutex);
915 static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
918 struct vhost_net *n = f->private_data;
919 void __user *argp = (void __user *)arg;
920 u64 __user *featurep = argp;
921 struct vhost_vring_file backend;
926 case VHOST_NET_SET_BACKEND:
927 if (copy_from_user(&backend, argp, sizeof backend))
929 return vhost_net_set_backend(n, backend.index, backend.fd);
930 case VHOST_GET_FEATURES:
931 features = VHOST_NET_FEATURES;
932 if (copy_to_user(featurep, &features, sizeof features))
935 case VHOST_SET_FEATURES:
936 if (copy_from_user(&features, featurep, sizeof features))
938 if (features & ~VHOST_NET_FEATURES)
940 return vhost_net_set_features(n, features);
941 case VHOST_RESET_OWNER:
942 return vhost_net_reset_owner(n);
944 mutex_lock(&n->dev.mutex);
945 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
946 if (r == -ENOIOCTLCMD)
947 r = vhost_vring_ioctl(&n->dev, ioctl, argp);
950 mutex_unlock(&n->dev.mutex);
956 static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
959 return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
963 static const struct file_operations vhost_net_fops = {
964 .owner = THIS_MODULE,
965 .release = vhost_net_release,
966 .unlocked_ioctl = vhost_net_ioctl,
968 .compat_ioctl = vhost_net_compat_ioctl,
970 .open = vhost_net_open,
971 .llseek = noop_llseek,
974 static struct miscdevice vhost_net_misc = {
975 .minor = VHOST_NET_MINOR,
977 .fops = &vhost_net_fops,
980 static int vhost_net_init(void)
982 if (experimental_zcopytx)
983 vhost_enable_zcopy(VHOST_NET_VQ_TX);
984 return misc_register(&vhost_net_misc);
986 module_init(vhost_net_init);
988 static void vhost_net_exit(void)
990 misc_deregister(&vhost_net_misc);
992 module_exit(vhost_net_exit);
994 MODULE_VERSION("0.0.1");
995 MODULE_LICENSE("GPL v2");
996 MODULE_AUTHOR("Michael S. Tsirkin");
997 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
998 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
999 MODULE_ALIAS("devname:vhost-net");