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 = 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 3
52 /* Lower device DMA done */
53 #define VHOST_DMA_DONE_LEN 2
54 /* Lower device DMA in progress */
55 #define VHOST_DMA_IN_PROGRESS 1
57 #define VHOST_DMA_CLEAR_LEN 0
59 #define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN)
69 struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX];
70 struct vhost_poll poll[VHOST_NET_VQ_MAX];
71 /* Number of TX recently submitted.
72 * Protected by tx vq lock. */
74 /* Number of times zerocopy TX recently failed.
75 * Protected by tx vq lock. */
76 unsigned tx_zcopy_err;
77 /* Flush in progress. Protected by tx vq lock. */
81 static void vhost_net_tx_packet(struct vhost_net *net)
84 if (net->tx_packets < 1024)
87 net->tx_zcopy_err = 0;
90 static void vhost_net_tx_err(struct vhost_net *net)
95 static bool vhost_net_tx_select_zcopy(struct vhost_net *net)
97 /* TX flush waits for outstanding DMAs to be done.
98 * Don't start new DMAs.
100 return !net->tx_flush &&
101 net->tx_packets / 64 >= net->tx_zcopy_err;
104 static bool vhost_sock_zcopy(struct socket *sock)
106 return unlikely(experimental_zcopytx) &&
107 sock_flag(sock->sk, SOCK_ZEROCOPY);
110 /* Pop first len bytes from iovec. Return number of segments used. */
111 static int move_iovec_hdr(struct iovec *from, struct iovec *to,
112 size_t len, int iov_count)
117 while (len && seg < iov_count) {
118 size = min(from->iov_len, len);
119 to->iov_base = from->iov_base;
121 from->iov_len -= size;
122 from->iov_base += size;
130 /* Copy iovec entries for len bytes from iovec. */
131 static void copy_iovec_hdr(const struct iovec *from, struct iovec *to,
132 size_t len, int iovcount)
137 while (len && seg < iovcount) {
138 size = min(from->iov_len, len);
139 to->iov_base = from->iov_base;
148 /* In case of DMA done not in order in lower device driver for some reason.
149 * upend_idx is used to track end of used idx, done_idx is used to track head
150 * of used idx. Once lower device DMA done contiguously, we will signal KVM
153 static int vhost_zerocopy_signal_used(struct vhost_net *net,
154 struct vhost_virtqueue *vq)
159 for (i = vq->done_idx; i != vq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
160 if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
161 vhost_net_tx_err(net);
162 if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
163 vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
164 vhost_add_used_and_signal(vq->dev, vq,
175 static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success)
177 struct vhost_ubuf_ref *ubufs = ubuf->ctx;
178 struct vhost_virtqueue *vq = ubufs->vq;
179 int cnt = atomic_read(&ubufs->kref.refcount);
182 * Trigger polling thread if guest stopped submitting new buffers:
183 * in this case, the refcount after decrement will eventually reach 1
185 * We also trigger polling periodically after each 16 packets
186 * (the value 16 here is more or less arbitrary, it's tuned to trigger
187 * less than 10% of times).
189 if (cnt <= 2 || !(cnt % 16))
190 vhost_poll_queue(&vq->poll);
191 /* set len to mark this desc buffers done DMA */
192 vq->heads[ubuf->desc].len = success ?
193 VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;
194 vhost_ubuf_put(ubufs);
197 /* Expects to be always run from workqueue - which acts as
198 * read-size critical section for our kind of RCU. */
199 static void handle_tx(struct vhost_net *net)
201 struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
204 struct msghdr msg = {
210 .msg_flags = MSG_DONTWAIT,
212 size_t len, total_len = 0;
216 struct vhost_ubuf_ref *uninitialized_var(ubufs);
217 bool zcopy, zcopy_used;
219 /* TODO: check that we are running from vhost_worker? */
220 sock = rcu_dereference_check(vq->private_data, 1);
224 mutex_lock(&vq->mutex);
225 vhost_disable_notify(&net->dev, vq);
227 hdr_size = vq->vhost_hlen;
231 /* Release DMAs done buffers first */
233 vhost_zerocopy_signal_used(net, vq);
235 head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
239 /* On error, stop handling until the next kick. */
240 if (unlikely(head < 0))
242 /* Nothing new? Wait for eventfd to tell us they refilled. */
243 if (head == vq->num) {
246 /* If more outstanding DMAs, queue the work.
247 * Handle upend_idx wrap around
249 num_pends = likely(vq->upend_idx >= vq->done_idx) ?
250 (vq->upend_idx - vq->done_idx) :
251 (vq->upend_idx + UIO_MAXIOV - vq->done_idx);
252 if (unlikely(num_pends > VHOST_MAX_PEND))
254 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
255 vhost_disable_notify(&net->dev, vq);
261 vq_err(vq, "Unexpected descriptor format for TX: "
262 "out %d, int %d\n", out, in);
265 /* Skip header. TODO: support TSO. */
266 s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out);
267 msg.msg_iovlen = out;
268 len = iov_length(vq->iov, out);
271 vq_err(vq, "Unexpected header len for TX: "
272 "%zd expected %zd\n",
273 iov_length(vq->hdr, s), hdr_size);
276 zcopy_used = zcopy && (len >= VHOST_GOODCOPY_LEN ||
277 vq->upend_idx != vq->done_idx);
279 /* use msg_control to pass vhost zerocopy ubuf info to skb */
281 vq->heads[vq->upend_idx].id = head;
282 if (!vhost_net_tx_select_zcopy(net) ||
283 len < VHOST_GOODCOPY_LEN) {
284 /* copy don't need to wait for DMA done */
285 vq->heads[vq->upend_idx].len =
287 msg.msg_control = NULL;
288 msg.msg_controllen = 0;
291 struct ubuf_info *ubuf;
292 ubuf = vq->ubuf_info + vq->upend_idx;
294 vq->heads[vq->upend_idx].len =
295 VHOST_DMA_IN_PROGRESS;
296 ubuf->callback = vhost_zerocopy_callback;
297 ubuf->ctx = vq->ubufs;
298 ubuf->desc = vq->upend_idx;
299 msg.msg_control = ubuf;
300 msg.msg_controllen = sizeof(ubuf);
302 kref_get(&ubufs->kref);
304 vq->upend_idx = (vq->upend_idx + 1) % UIO_MAXIOV;
306 /* TODO: Check specific error and bomb out unless ENOBUFS? */
307 err = sock->ops->sendmsg(NULL, sock, &msg, len);
308 if (unlikely(err < 0)) {
311 vhost_ubuf_put(ubufs);
312 vq->upend_idx = ((unsigned)vq->upend_idx - 1) %
315 vhost_discard_vq_desc(vq, 1);
319 pr_debug("Truncated TX packet: "
320 " len %d != %zd\n", err, len);
322 vhost_add_used_and_signal(&net->dev, vq, head, 0);
324 vhost_zerocopy_signal_used(net, vq);
326 vhost_net_tx_packet(net);
327 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
328 vhost_poll_queue(&vq->poll);
333 mutex_unlock(&vq->mutex);
336 static int peek_head_len(struct sock *sk)
338 struct sk_buff *head;
342 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
343 head = skb_peek(&sk->sk_receive_queue);
346 if (vlan_tx_tag_present(head))
350 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
354 /* This is a multi-buffer version of vhost_get_desc, that works if
355 * vq has read descriptors only.
356 * @vq - the relevant virtqueue
357 * @datalen - data length we'll be reading
358 * @iovcount - returned count of io vectors we fill
360 * @log_num - log offset
361 * @quota - headcount quota, 1 for big buffer
362 * returns number of buffer heads allocated, negative on error
364 static int get_rx_bufs(struct vhost_virtqueue *vq,
365 struct vring_used_elem *heads,
368 struct vhost_log *log,
372 unsigned int out, in;
378 while (datalen > 0 && headcount < quota) {
379 if (unlikely(seg >= UIO_MAXIOV)) {
383 d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
384 ARRAY_SIZE(vq->iov) - seg, &out,
390 if (unlikely(out || in <= 0)) {
391 vq_err(vq, "unexpected descriptor format for RX: "
392 "out %d, in %d\n", out, in);
400 heads[headcount].id = d;
401 heads[headcount].len = iov_length(vq->iov + seg, in);
402 datalen -= heads[headcount].len;
406 heads[headcount - 1].len += datalen;
412 vhost_discard_vq_desc(vq, headcount);
416 /* Expects to be always run from workqueue - which acts as
417 * read-size critical section for our kind of RCU. */
418 static void handle_rx(struct vhost_net *net)
420 struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
421 unsigned uninitialized_var(in), log;
422 struct vhost_log *vq_log;
423 struct msghdr msg = {
426 .msg_control = NULL, /* FIXME: get and handle RX aux data. */
429 .msg_flags = MSG_DONTWAIT,
431 struct virtio_net_hdr_mrg_rxbuf hdr = {
433 .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
435 size_t total_len = 0;
438 size_t vhost_hlen, sock_hlen;
439 size_t vhost_len, sock_len;
440 /* TODO: check that we are running from vhost_worker? */
441 struct socket *sock = rcu_dereference_check(vq->private_data, 1);
446 mutex_lock(&vq->mutex);
447 vhost_disable_notify(&net->dev, vq);
448 vhost_hlen = vq->vhost_hlen;
449 sock_hlen = vq->sock_hlen;
451 vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
453 mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);
455 while ((sock_len = peek_head_len(sock->sk))) {
456 sock_len += sock_hlen;
457 vhost_len = sock_len + vhost_hlen;
458 headcount = get_rx_bufs(vq, vq->heads, vhost_len,
460 likely(mergeable) ? UIO_MAXIOV : 1);
461 /* On error, stop handling until the next kick. */
462 if (unlikely(headcount < 0))
464 /* OK, now we need to know about added descriptors. */
466 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
467 /* They have slipped one in as we were
468 * doing that: check again. */
469 vhost_disable_notify(&net->dev, vq);
472 /* Nothing new? Wait for eventfd to tell us
476 /* We don't need to be notified again. */
477 if (unlikely((vhost_hlen)))
478 /* Skip header. TODO: support TSO. */
479 move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in);
481 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
482 * needed because recvmsg can modify msg_iov. */
483 copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in);
485 err = sock->ops->recvmsg(NULL, sock, &msg,
486 sock_len, MSG_DONTWAIT | MSG_TRUNC);
487 /* Userspace might have consumed the packet meanwhile:
488 * it's not supposed to do this usually, but might be hard
489 * to prevent. Discard data we got (if any) and keep going. */
490 if (unlikely(err != sock_len)) {
491 pr_debug("Discarded rx packet: "
492 " len %d, expected %zd\n", err, sock_len);
493 vhost_discard_vq_desc(vq, headcount);
496 if (unlikely(vhost_hlen) &&
497 memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0,
499 vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
503 /* TODO: Should check and handle checksum. */
504 if (likely(mergeable) &&
505 memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount,
506 offsetof(typeof(hdr), num_buffers),
507 sizeof hdr.num_buffers)) {
508 vq_err(vq, "Failed num_buffers write");
509 vhost_discard_vq_desc(vq, headcount);
512 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
514 if (unlikely(vq_log))
515 vhost_log_write(vq, vq_log, log, vhost_len);
516 total_len += vhost_len;
517 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
518 vhost_poll_queue(&vq->poll);
523 mutex_unlock(&vq->mutex);
526 static void handle_tx_kick(struct vhost_work *work)
528 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
530 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
535 static void handle_rx_kick(struct vhost_work *work)
537 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
539 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
544 static void handle_tx_net(struct vhost_work *work)
546 struct vhost_net *net = container_of(work, struct vhost_net,
547 poll[VHOST_NET_VQ_TX].work);
551 static void handle_rx_net(struct vhost_work *work)
553 struct vhost_net *net = container_of(work, struct vhost_net,
554 poll[VHOST_NET_VQ_RX].work);
558 static int vhost_net_open(struct inode *inode, struct file *f)
560 struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
561 struct vhost_dev *dev;
568 n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
569 n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
570 r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
576 vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
577 vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
584 static void vhost_net_disable_vq(struct vhost_net *n,
585 struct vhost_virtqueue *vq)
587 struct vhost_poll *poll = n->poll + (vq - n->vqs);
588 if (!vq->private_data)
590 vhost_poll_stop(poll);
593 static int vhost_net_enable_vq(struct vhost_net *n,
594 struct vhost_virtqueue *vq)
596 struct vhost_poll *poll = n->poll + (vq - n->vqs);
599 sock = rcu_dereference_protected(vq->private_data,
600 lockdep_is_held(&vq->mutex));
604 return vhost_poll_start(poll, sock->file);
607 static struct socket *vhost_net_stop_vq(struct vhost_net *n,
608 struct vhost_virtqueue *vq)
612 mutex_lock(&vq->mutex);
613 sock = rcu_dereference_protected(vq->private_data,
614 lockdep_is_held(&vq->mutex));
615 vhost_net_disable_vq(n, vq);
616 rcu_assign_pointer(vq->private_data, NULL);
617 mutex_unlock(&vq->mutex);
621 static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
622 struct socket **rx_sock)
624 *tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX);
625 *rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX);
628 static void vhost_net_flush_vq(struct vhost_net *n, int index)
630 vhost_poll_flush(n->poll + index);
631 vhost_poll_flush(&n->dev.vqs[index].poll);
634 static void vhost_net_flush(struct vhost_net *n)
636 vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
637 vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
638 if (n->dev.vqs[VHOST_NET_VQ_TX].ubufs) {
639 mutex_lock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
641 mutex_unlock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
642 /* Wait for all lower device DMAs done. */
643 vhost_ubuf_put_and_wait(n->dev.vqs[VHOST_NET_VQ_TX].ubufs);
644 mutex_lock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
646 kref_init(&n->dev.vqs[VHOST_NET_VQ_TX].ubufs->kref);
647 mutex_unlock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
651 static int vhost_net_release(struct inode *inode, struct file *f)
653 struct vhost_net *n = f->private_data;
654 struct socket *tx_sock;
655 struct socket *rx_sock;
657 vhost_net_stop(n, &tx_sock, &rx_sock);
659 vhost_dev_stop(&n->dev);
660 vhost_dev_cleanup(&n->dev, false);
665 /* We do an extra flush before freeing memory,
666 * since jobs can re-queue themselves. */
672 static struct socket *get_raw_socket(int fd)
675 struct sockaddr_ll sa;
676 char buf[MAX_ADDR_LEN];
678 int uaddr_len = sizeof uaddr, r;
679 struct socket *sock = sockfd_lookup(fd, &r);
682 return ERR_PTR(-ENOTSOCK);
684 /* Parameter checking */
685 if (sock->sk->sk_type != SOCK_RAW) {
686 r = -ESOCKTNOSUPPORT;
690 r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
695 if (uaddr.sa.sll_family != AF_PACKET) {
705 static struct socket *get_tap_socket(int fd)
707 struct file *file = fget(fd);
711 return ERR_PTR(-EBADF);
712 sock = tun_get_socket(file);
715 sock = macvtap_get_socket(file);
721 static struct socket *get_socket(int fd)
725 /* special case to disable backend */
728 sock = get_raw_socket(fd);
731 sock = get_tap_socket(fd);
734 return ERR_PTR(-ENOTSOCK);
737 static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
739 struct socket *sock, *oldsock;
740 struct vhost_virtqueue *vq;
741 struct vhost_ubuf_ref *ubufs, *oldubufs = NULL;
744 mutex_lock(&n->dev.mutex);
745 r = vhost_dev_check_owner(&n->dev);
749 if (index >= VHOST_NET_VQ_MAX) {
754 mutex_lock(&vq->mutex);
756 /* Verify that ring has been setup correctly. */
757 if (!vhost_vq_access_ok(vq)) {
761 sock = get_socket(fd);
767 /* start polling new socket */
768 oldsock = rcu_dereference_protected(vq->private_data,
769 lockdep_is_held(&vq->mutex));
770 if (sock != oldsock) {
771 ubufs = vhost_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock));
777 vhost_net_disable_vq(n, vq);
778 rcu_assign_pointer(vq->private_data, sock);
779 r = vhost_init_used(vq);
782 r = vhost_net_enable_vq(n, vq);
786 oldubufs = vq->ubufs;
794 mutex_unlock(&vq->mutex);
797 vhost_ubuf_put_and_wait(oldubufs);
798 mutex_lock(&vq->mutex);
799 vhost_zerocopy_signal_used(n, vq);
800 mutex_unlock(&vq->mutex);
804 vhost_net_flush_vq(n, index);
808 mutex_unlock(&n->dev.mutex);
812 rcu_assign_pointer(vq->private_data, oldsock);
813 vhost_net_enable_vq(n, vq);
815 vhost_ubuf_put_and_wait(ubufs);
819 mutex_unlock(&vq->mutex);
821 mutex_unlock(&n->dev.mutex);
825 static long vhost_net_reset_owner(struct vhost_net *n)
827 struct socket *tx_sock = NULL;
828 struct socket *rx_sock = NULL;
831 mutex_lock(&n->dev.mutex);
832 err = vhost_dev_check_owner(&n->dev);
835 vhost_net_stop(n, &tx_sock, &rx_sock);
837 err = vhost_dev_reset_owner(&n->dev);
839 mutex_unlock(&n->dev.mutex);
847 static int vhost_net_set_features(struct vhost_net *n, u64 features)
849 size_t vhost_hlen, sock_hlen, hdr_len;
852 hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
853 sizeof(struct virtio_net_hdr_mrg_rxbuf) :
854 sizeof(struct virtio_net_hdr);
855 if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
856 /* vhost provides vnet_hdr */
857 vhost_hlen = hdr_len;
860 /* socket provides vnet_hdr */
864 mutex_lock(&n->dev.mutex);
865 if ((features & (1 << VHOST_F_LOG_ALL)) &&
866 !vhost_log_access_ok(&n->dev)) {
867 mutex_unlock(&n->dev.mutex);
870 n->dev.acked_features = features;
872 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
873 mutex_lock(&n->vqs[i].mutex);
874 n->vqs[i].vhost_hlen = vhost_hlen;
875 n->vqs[i].sock_hlen = sock_hlen;
876 mutex_unlock(&n->vqs[i].mutex);
879 mutex_unlock(&n->dev.mutex);
883 static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
886 struct vhost_net *n = f->private_data;
887 void __user *argp = (void __user *)arg;
888 u64 __user *featurep = argp;
889 struct vhost_vring_file backend;
894 case VHOST_NET_SET_BACKEND:
895 if (copy_from_user(&backend, argp, sizeof backend))
897 return vhost_net_set_backend(n, backend.index, backend.fd);
898 case VHOST_GET_FEATURES:
899 features = VHOST_NET_FEATURES;
900 if (copy_to_user(featurep, &features, sizeof features))
903 case VHOST_SET_FEATURES:
904 if (copy_from_user(&features, featurep, sizeof features))
906 if (features & ~VHOST_NET_FEATURES)
908 return vhost_net_set_features(n, features);
909 case VHOST_RESET_OWNER:
910 return vhost_net_reset_owner(n);
912 mutex_lock(&n->dev.mutex);
913 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
914 if (r == -ENOIOCTLCMD)
915 r = vhost_vring_ioctl(&n->dev, ioctl, argp);
918 mutex_unlock(&n->dev.mutex);
924 static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
927 return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
931 static const struct file_operations vhost_net_fops = {
932 .owner = THIS_MODULE,
933 .release = vhost_net_release,
934 .unlocked_ioctl = vhost_net_ioctl,
936 .compat_ioctl = vhost_net_compat_ioctl,
938 .open = vhost_net_open,
939 .llseek = noop_llseek,
942 static struct miscdevice vhost_net_misc = {
943 .minor = VHOST_NET_MINOR,
945 .fops = &vhost_net_fops,
948 static int vhost_net_init(void)
950 if (experimental_zcopytx)
951 vhost_enable_zcopy(VHOST_NET_VQ_TX);
952 return misc_register(&vhost_net_misc);
954 module_init(vhost_net_init);
956 static void vhost_net_exit(void)
958 misc_deregister(&vhost_net_misc);
960 module_exit(vhost_net_exit);
962 MODULE_VERSION("0.0.1");
963 MODULE_LICENSE("GPL v2");
964 MODULE_AUTHOR("Michael S. Tsirkin");
965 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
966 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
967 MODULE_ALIAS("devname:vhost-net");