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
51 enum vhost_net_poll_state
{
52 VHOST_NET_POLL_DISABLED
= 0,
53 VHOST_NET_POLL_STARTED
= 1,
54 VHOST_NET_POLL_STOPPED
= 2,
59 struct vhost_virtqueue vqs
[VHOST_NET_VQ_MAX
];
60 struct vhost_poll poll
[VHOST_NET_VQ_MAX
];
61 /* Tells us whether we are polling a socket for TX.
62 * We only do this when socket buffer fills up.
63 * Protected by tx vq lock. */
64 enum vhost_net_poll_state tx_poll_state
;
67 static bool vhost_sock_zcopy(struct socket
*sock
)
69 return unlikely(experimental_zcopytx
) &&
70 sock_flag(sock
->sk
, SOCK_ZEROCOPY
);
73 /* Pop first len bytes from iovec. Return number of segments used. */
74 static int move_iovec_hdr(struct iovec
*from
, struct iovec
*to
,
75 size_t len
, int iov_count
)
80 while (len
&& seg
< iov_count
) {
81 size
= min(from
->iov_len
, len
);
82 to
->iov_base
= from
->iov_base
;
84 from
->iov_len
-= size
;
85 from
->iov_base
+= size
;
93 /* Copy iovec entries for len bytes from iovec. */
94 static void copy_iovec_hdr(const struct iovec
*from
, struct iovec
*to
,
95 size_t len
, int iovcount
)
100 while (len
&& seg
< iovcount
) {
101 size
= min(from
->iov_len
, len
);
102 to
->iov_base
= from
->iov_base
;
111 /* Caller must have TX VQ lock */
112 static void tx_poll_stop(struct vhost_net
*net
)
114 if (likely(net
->tx_poll_state
!= VHOST_NET_POLL_STARTED
))
116 vhost_poll_stop(net
->poll
+ VHOST_NET_VQ_TX
);
117 net
->tx_poll_state
= VHOST_NET_POLL_STOPPED
;
120 /* Caller must have TX VQ lock */
121 static void tx_poll_start(struct vhost_net
*net
, struct socket
*sock
)
123 if (unlikely(net
->tx_poll_state
!= VHOST_NET_POLL_STOPPED
))
125 vhost_poll_start(net
->poll
+ VHOST_NET_VQ_TX
, sock
->file
);
126 net
->tx_poll_state
= VHOST_NET_POLL_STARTED
;
129 /* Expects to be always run from workqueue - which acts as
130 * read-size critical section for our kind of RCU. */
131 static void handle_tx(struct vhost_net
*net
)
133 struct vhost_virtqueue
*vq
= &net
->dev
.vqs
[VHOST_NET_VQ_TX
];
136 struct msghdr msg
= {
142 .msg_flags
= MSG_DONTWAIT
,
144 size_t len
, total_len
= 0;
148 struct vhost_ubuf_ref
*uninitialized_var(ubufs
);
151 /* TODO: check that we are running from vhost_worker? */
152 sock
= rcu_dereference_check(vq
->private_data
, 1);
156 wmem
= atomic_read(&sock
->sk
->sk_wmem_alloc
);
157 if (wmem
>= sock
->sk
->sk_sndbuf
) {
158 mutex_lock(&vq
->mutex
);
159 tx_poll_start(net
, sock
);
160 mutex_unlock(&vq
->mutex
);
164 mutex_lock(&vq
->mutex
);
165 vhost_disable_notify(&net
->dev
, vq
);
167 if (wmem
< sock
->sk
->sk_sndbuf
/ 2)
169 hdr_size
= vq
->vhost_hlen
;
173 /* Release DMAs done buffers first */
175 vhost_zerocopy_signal_used(vq
);
177 head
= vhost_get_vq_desc(&net
->dev
, vq
, vq
->iov
,
181 /* On error, stop handling until the next kick. */
182 if (unlikely(head
< 0))
184 /* Nothing new? Wait for eventfd to tell us they refilled. */
185 if (head
== vq
->num
) {
188 wmem
= atomic_read(&sock
->sk
->sk_wmem_alloc
);
189 if (wmem
>= sock
->sk
->sk_sndbuf
* 3 / 4) {
190 tx_poll_start(net
, sock
);
191 set_bit(SOCK_ASYNC_NOSPACE
, &sock
->flags
);
194 /* If more outstanding DMAs, queue the work.
195 * Handle upend_idx wrap around
197 num_pends
= likely(vq
->upend_idx
>= vq
->done_idx
) ?
198 (vq
->upend_idx
- vq
->done_idx
) :
199 (vq
->upend_idx
+ UIO_MAXIOV
- vq
->done_idx
);
200 if (unlikely(num_pends
> VHOST_MAX_PEND
)) {
201 tx_poll_start(net
, sock
);
202 set_bit(SOCK_ASYNC_NOSPACE
, &sock
->flags
);
205 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
206 vhost_disable_notify(&net
->dev
, vq
);
212 vq_err(vq
, "Unexpected descriptor format for TX: "
213 "out %d, int %d\n", out
, in
);
216 /* Skip header. TODO: support TSO. */
217 s
= move_iovec_hdr(vq
->iov
, vq
->hdr
, hdr_size
, out
);
218 msg
.msg_iovlen
= out
;
219 len
= iov_length(vq
->iov
, out
);
222 vq_err(vq
, "Unexpected header len for TX: "
223 "%zd expected %zd\n",
224 iov_length(vq
->hdr
, s
), hdr_size
);
227 /* use msg_control to pass vhost zerocopy ubuf info to skb */
229 vq
->heads
[vq
->upend_idx
].id
= head
;
230 if (len
< VHOST_GOODCOPY_LEN
) {
231 /* copy don't need to wait for DMA done */
232 vq
->heads
[vq
->upend_idx
].len
=
234 msg
.msg_control
= NULL
;
235 msg
.msg_controllen
= 0;
238 struct ubuf_info
*ubuf
= &vq
->ubuf_info
[head
];
240 vq
->heads
[vq
->upend_idx
].len
= len
;
241 ubuf
->callback
= vhost_zerocopy_callback
;
242 ubuf
->ctx
= vq
->ubufs
;
243 ubuf
->desc
= vq
->upend_idx
;
244 msg
.msg_control
= ubuf
;
245 msg
.msg_controllen
= sizeof(ubuf
);
247 kref_get(&ubufs
->kref
);
249 vq
->upend_idx
= (vq
->upend_idx
+ 1) % UIO_MAXIOV
;
251 /* TODO: Check specific error and bomb out unless ENOBUFS? */
252 err
= sock
->ops
->sendmsg(NULL
, sock
, &msg
, len
);
253 if (unlikely(err
< 0)) {
256 vhost_ubuf_put(ubufs
);
257 vq
->upend_idx
= ((unsigned)vq
->upend_idx
- 1) %
260 vhost_discard_vq_desc(vq
, 1);
261 if (err
== -EAGAIN
|| err
== -ENOBUFS
)
262 tx_poll_start(net
, sock
);
266 pr_debug("Truncated TX packet: "
267 " len %d != %zd\n", err
, len
);
269 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
271 vhost_zerocopy_signal_used(vq
);
273 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
274 vhost_poll_queue(&vq
->poll
);
279 mutex_unlock(&vq
->mutex
);
282 static int peek_head_len(struct sock
*sk
)
284 struct sk_buff
*head
;
288 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
289 head
= skb_peek(&sk
->sk_receive_queue
);
292 if (vlan_tx_tag_present(head
))
296 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
300 /* This is a multi-buffer version of vhost_get_desc, that works if
301 * vq has read descriptors only.
302 * @vq - the relevant virtqueue
303 * @datalen - data length we'll be reading
304 * @iovcount - returned count of io vectors we fill
306 * @log_num - log offset
307 * @quota - headcount quota, 1 for big buffer
308 * returns number of buffer heads allocated, negative on error
310 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
311 struct vring_used_elem
*heads
,
314 struct vhost_log
*log
,
318 unsigned int out
, in
;
324 while (datalen
> 0 && headcount
< quota
) {
325 if (unlikely(seg
>= UIO_MAXIOV
)) {
329 d
= vhost_get_vq_desc(vq
->dev
, vq
, vq
->iov
+ seg
,
330 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
336 if (unlikely(out
|| in
<= 0)) {
337 vq_err(vq
, "unexpected descriptor format for RX: "
338 "out %d, in %d\n", out
, in
);
346 heads
[headcount
].id
= d
;
347 heads
[headcount
].len
= iov_length(vq
->iov
+ seg
, in
);
348 datalen
-= heads
[headcount
].len
;
352 heads
[headcount
- 1].len
+= datalen
;
358 vhost_discard_vq_desc(vq
, headcount
);
362 /* Expects to be always run from workqueue - which acts as
363 * read-size critical section for our kind of RCU. */
364 static void handle_rx(struct vhost_net
*net
)
366 struct vhost_virtqueue
*vq
= &net
->dev
.vqs
[VHOST_NET_VQ_RX
];
367 unsigned uninitialized_var(in
), log
;
368 struct vhost_log
*vq_log
;
369 struct msghdr msg
= {
372 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
375 .msg_flags
= MSG_DONTWAIT
,
377 struct virtio_net_hdr_mrg_rxbuf hdr
= {
379 .hdr
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
381 size_t total_len
= 0;
384 size_t vhost_hlen
, sock_hlen
;
385 size_t vhost_len
, sock_len
;
386 /* TODO: check that we are running from vhost_worker? */
387 struct socket
*sock
= rcu_dereference_check(vq
->private_data
, 1);
392 mutex_lock(&vq
->mutex
);
393 vhost_disable_notify(&net
->dev
, vq
);
394 vhost_hlen
= vq
->vhost_hlen
;
395 sock_hlen
= vq
->sock_hlen
;
397 vq_log
= unlikely(vhost_has_feature(&net
->dev
, VHOST_F_LOG_ALL
)) ?
399 mergeable
= vhost_has_feature(&net
->dev
, VIRTIO_NET_F_MRG_RXBUF
);
401 while ((sock_len
= peek_head_len(sock
->sk
))) {
402 sock_len
+= sock_hlen
;
403 vhost_len
= sock_len
+ vhost_hlen
;
404 headcount
= get_rx_bufs(vq
, vq
->heads
, vhost_len
,
406 likely(mergeable
) ? UIO_MAXIOV
: 1);
407 /* On error, stop handling until the next kick. */
408 if (unlikely(headcount
< 0))
410 /* OK, now we need to know about added descriptors. */
412 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
413 /* They have slipped one in as we were
414 * doing that: check again. */
415 vhost_disable_notify(&net
->dev
, vq
);
418 /* Nothing new? Wait for eventfd to tell us
422 /* We don't need to be notified again. */
423 if (unlikely((vhost_hlen
)))
424 /* Skip header. TODO: support TSO. */
425 move_iovec_hdr(vq
->iov
, vq
->hdr
, vhost_hlen
, in
);
427 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
428 * needed because recvmsg can modify msg_iov. */
429 copy_iovec_hdr(vq
->iov
, vq
->hdr
, sock_hlen
, in
);
431 err
= sock
->ops
->recvmsg(NULL
, sock
, &msg
,
432 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
433 /* Userspace might have consumed the packet meanwhile:
434 * it's not supposed to do this usually, but might be hard
435 * to prevent. Discard data we got (if any) and keep going. */
436 if (unlikely(err
!= sock_len
)) {
437 pr_debug("Discarded rx packet: "
438 " len %d, expected %zd\n", err
, sock_len
);
439 vhost_discard_vq_desc(vq
, headcount
);
442 if (unlikely(vhost_hlen
) &&
443 memcpy_toiovecend(vq
->hdr
, (unsigned char *)&hdr
, 0,
445 vq_err(vq
, "Unable to write vnet_hdr at addr %p\n",
449 /* TODO: Should check and handle checksum. */
450 if (likely(mergeable
) &&
451 memcpy_toiovecend(vq
->hdr
, (unsigned char *)&headcount
,
452 offsetof(typeof(hdr
), num_buffers
),
453 sizeof hdr
.num_buffers
)) {
454 vq_err(vq
, "Failed num_buffers write");
455 vhost_discard_vq_desc(vq
, headcount
);
458 vhost_add_used_and_signal_n(&net
->dev
, vq
, vq
->heads
,
460 if (unlikely(vq_log
))
461 vhost_log_write(vq
, vq_log
, log
, vhost_len
);
462 total_len
+= vhost_len
;
463 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
464 vhost_poll_queue(&vq
->poll
);
469 mutex_unlock(&vq
->mutex
);
472 static void handle_tx_kick(struct vhost_work
*work
)
474 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
476 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
481 static void handle_rx_kick(struct vhost_work
*work
)
483 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
485 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
490 static void handle_tx_net(struct vhost_work
*work
)
492 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
493 poll
[VHOST_NET_VQ_TX
].work
);
497 static void handle_rx_net(struct vhost_work
*work
)
499 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
500 poll
[VHOST_NET_VQ_RX
].work
);
504 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
506 struct vhost_net
*n
= kmalloc(sizeof *n
, GFP_KERNEL
);
507 struct vhost_dev
*dev
;
514 n
->vqs
[VHOST_NET_VQ_TX
].handle_kick
= handle_tx_kick
;
515 n
->vqs
[VHOST_NET_VQ_RX
].handle_kick
= handle_rx_kick
;
516 r
= vhost_dev_init(dev
, n
->vqs
, VHOST_NET_VQ_MAX
);
522 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, POLLOUT
, dev
);
523 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, POLLIN
, dev
);
524 n
->tx_poll_state
= VHOST_NET_POLL_DISABLED
;
531 static void vhost_net_disable_vq(struct vhost_net
*n
,
532 struct vhost_virtqueue
*vq
)
534 if (!vq
->private_data
)
536 if (vq
== n
->vqs
+ VHOST_NET_VQ_TX
) {
538 n
->tx_poll_state
= VHOST_NET_POLL_DISABLED
;
540 vhost_poll_stop(n
->poll
+ VHOST_NET_VQ_RX
);
543 static void vhost_net_enable_vq(struct vhost_net
*n
,
544 struct vhost_virtqueue
*vq
)
548 sock
= rcu_dereference_protected(vq
->private_data
,
549 lockdep_is_held(&vq
->mutex
));
552 if (vq
== n
->vqs
+ VHOST_NET_VQ_TX
) {
553 n
->tx_poll_state
= VHOST_NET_POLL_STOPPED
;
554 tx_poll_start(n
, sock
);
556 vhost_poll_start(n
->poll
+ VHOST_NET_VQ_RX
, sock
->file
);
559 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
560 struct vhost_virtqueue
*vq
)
564 mutex_lock(&vq
->mutex
);
565 sock
= rcu_dereference_protected(vq
->private_data
,
566 lockdep_is_held(&vq
->mutex
));
567 vhost_net_disable_vq(n
, vq
);
568 rcu_assign_pointer(vq
->private_data
, NULL
);
569 mutex_unlock(&vq
->mutex
);
573 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
574 struct socket
**rx_sock
)
576 *tx_sock
= vhost_net_stop_vq(n
, n
->vqs
+ VHOST_NET_VQ_TX
);
577 *rx_sock
= vhost_net_stop_vq(n
, n
->vqs
+ VHOST_NET_VQ_RX
);
580 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
582 vhost_poll_flush(n
->poll
+ index
);
583 vhost_poll_flush(&n
->dev
.vqs
[index
].poll
);
586 static void vhost_net_flush(struct vhost_net
*n
)
588 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
589 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
592 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
594 struct vhost_net
*n
= f
->private_data
;
595 struct socket
*tx_sock
;
596 struct socket
*rx_sock
;
598 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
600 vhost_dev_cleanup(&n
->dev
, false);
605 /* We do an extra flush before freeing memory,
606 * since jobs can re-queue themselves. */
612 static struct socket
*get_raw_socket(int fd
)
615 struct sockaddr_ll sa
;
616 char buf
[MAX_ADDR_LEN
];
618 int uaddr_len
= sizeof uaddr
, r
;
619 struct socket
*sock
= sockfd_lookup(fd
, &r
);
622 return ERR_PTR(-ENOTSOCK
);
624 /* Parameter checking */
625 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
626 r
= -ESOCKTNOSUPPORT
;
630 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
,
635 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
645 static struct socket
*get_tap_socket(int fd
)
647 struct file
*file
= fget(fd
);
651 return ERR_PTR(-EBADF
);
652 sock
= tun_get_socket(file
);
655 sock
= macvtap_get_socket(file
);
661 static struct socket
*get_socket(int fd
)
665 /* special case to disable backend */
668 sock
= get_raw_socket(fd
);
671 sock
= get_tap_socket(fd
);
674 return ERR_PTR(-ENOTSOCK
);
677 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
679 struct socket
*sock
, *oldsock
;
680 struct vhost_virtqueue
*vq
;
681 struct vhost_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
684 mutex_lock(&n
->dev
.mutex
);
685 r
= vhost_dev_check_owner(&n
->dev
);
689 if (index
>= VHOST_NET_VQ_MAX
) {
694 mutex_lock(&vq
->mutex
);
696 /* Verify that ring has been setup correctly. */
697 if (!vhost_vq_access_ok(vq
)) {
701 sock
= get_socket(fd
);
707 /* start polling new socket */
708 oldsock
= rcu_dereference_protected(vq
->private_data
,
709 lockdep_is_held(&vq
->mutex
));
710 if (sock
!= oldsock
) {
711 ubufs
= vhost_ubuf_alloc(vq
, sock
&& vhost_sock_zcopy(sock
));
716 oldubufs
= vq
->ubufs
;
718 vhost_net_disable_vq(n
, vq
);
719 rcu_assign_pointer(vq
->private_data
, sock
);
720 vhost_net_enable_vq(n
, vq
);
722 r
= vhost_init_used(vq
);
727 mutex_unlock(&vq
->mutex
);
730 vhost_ubuf_put_and_wait(oldubufs
);
731 mutex_lock(&vq
->mutex
);
732 vhost_zerocopy_signal_used(vq
);
733 mutex_unlock(&vq
->mutex
);
737 vhost_net_flush_vq(n
, index
);
741 mutex_unlock(&n
->dev
.mutex
);
747 mutex_unlock(&vq
->mutex
);
749 mutex_unlock(&n
->dev
.mutex
);
753 static long vhost_net_reset_owner(struct vhost_net
*n
)
755 struct socket
*tx_sock
= NULL
;
756 struct socket
*rx_sock
= NULL
;
759 mutex_lock(&n
->dev
.mutex
);
760 err
= vhost_dev_check_owner(&n
->dev
);
763 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
765 err
= vhost_dev_reset_owner(&n
->dev
);
767 mutex_unlock(&n
->dev
.mutex
);
775 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
777 size_t vhost_hlen
, sock_hlen
, hdr_len
;
780 hdr_len
= (features
& (1 << VIRTIO_NET_F_MRG_RXBUF
)) ?
781 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
782 sizeof(struct virtio_net_hdr
);
783 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
784 /* vhost provides vnet_hdr */
785 vhost_hlen
= hdr_len
;
788 /* socket provides vnet_hdr */
792 mutex_lock(&n
->dev
.mutex
);
793 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
794 !vhost_log_access_ok(&n
->dev
)) {
795 mutex_unlock(&n
->dev
.mutex
);
798 n
->dev
.acked_features
= features
;
800 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
801 mutex_lock(&n
->vqs
[i
].mutex
);
802 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
803 n
->vqs
[i
].sock_hlen
= sock_hlen
;
804 mutex_unlock(&n
->vqs
[i
].mutex
);
807 mutex_unlock(&n
->dev
.mutex
);
811 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
814 struct vhost_net
*n
= f
->private_data
;
815 void __user
*argp
= (void __user
*)arg
;
816 u64 __user
*featurep
= argp
;
817 struct vhost_vring_file backend
;
822 case VHOST_NET_SET_BACKEND
:
823 if (copy_from_user(&backend
, argp
, sizeof backend
))
825 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
826 case VHOST_GET_FEATURES
:
827 features
= VHOST_NET_FEATURES
;
828 if (copy_to_user(featurep
, &features
, sizeof features
))
831 case VHOST_SET_FEATURES
:
832 if (copy_from_user(&features
, featurep
, sizeof features
))
834 if (features
& ~VHOST_NET_FEATURES
)
836 return vhost_net_set_features(n
, features
);
837 case VHOST_RESET_OWNER
:
838 return vhost_net_reset_owner(n
);
840 mutex_lock(&n
->dev
.mutex
);
841 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, arg
);
843 mutex_unlock(&n
->dev
.mutex
);
849 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
852 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
856 static const struct file_operations vhost_net_fops
= {
857 .owner
= THIS_MODULE
,
858 .release
= vhost_net_release
,
859 .unlocked_ioctl
= vhost_net_ioctl
,
861 .compat_ioctl
= vhost_net_compat_ioctl
,
863 .open
= vhost_net_open
,
864 .llseek
= noop_llseek
,
867 static struct miscdevice vhost_net_misc
= {
868 .minor
= VHOST_NET_MINOR
,
870 .fops
= &vhost_net_fops
,
873 static int vhost_net_init(void)
875 if (experimental_zcopytx
)
876 vhost_enable_zcopy(VHOST_NET_VQ_TX
);
877 return misc_register(&vhost_net_misc
);
879 module_init(vhost_net_init
);
881 static void vhost_net_exit(void)
883 misc_deregister(&vhost_net_misc
);
885 module_exit(vhost_net_exit
);
887 MODULE_VERSION("0.0.1");
888 MODULE_LICENSE("GPL v2");
889 MODULE_AUTHOR("Michael S. Tsirkin");
890 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
891 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
892 MODULE_ALIAS("devname:vhost-net");