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
);
828 mutex_unlock(&vq
->mutex
);
831 vhost_ubuf_put_and_wait(oldubufs
);
832 mutex_lock(&vq
->mutex
);
833 vhost_zerocopy_signal_used(n
, vq
);
834 mutex_unlock(&vq
->mutex
);
838 vhost_net_flush_vq(n
, index
);
842 mutex_unlock(&n
->dev
.mutex
);
848 mutex_unlock(&vq
->mutex
);
850 mutex_unlock(&n
->dev
.mutex
);
854 static long vhost_net_reset_owner(struct vhost_net
*n
)
856 struct socket
*tx_sock
= NULL
;
857 struct socket
*rx_sock
= NULL
;
860 mutex_lock(&n
->dev
.mutex
);
861 err
= vhost_dev_check_owner(&n
->dev
);
864 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
866 err
= vhost_dev_reset_owner(&n
->dev
);
868 mutex_unlock(&n
->dev
.mutex
);
876 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
878 size_t vhost_hlen
, sock_hlen
, hdr_len
;
881 hdr_len
= (features
& (1 << VIRTIO_NET_F_MRG_RXBUF
)) ?
882 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
883 sizeof(struct virtio_net_hdr
);
884 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
885 /* vhost provides vnet_hdr */
886 vhost_hlen
= hdr_len
;
889 /* socket provides vnet_hdr */
893 mutex_lock(&n
->dev
.mutex
);
894 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
895 !vhost_log_access_ok(&n
->dev
)) {
896 mutex_unlock(&n
->dev
.mutex
);
899 n
->dev
.acked_features
= features
;
901 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
902 mutex_lock(&n
->vqs
[i
].mutex
);
903 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
904 n
->vqs
[i
].sock_hlen
= sock_hlen
;
905 mutex_unlock(&n
->vqs
[i
].mutex
);
908 mutex_unlock(&n
->dev
.mutex
);
912 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
915 struct vhost_net
*n
= f
->private_data
;
916 void __user
*argp
= (void __user
*)arg
;
917 u64 __user
*featurep
= argp
;
918 struct vhost_vring_file backend
;
923 case VHOST_NET_SET_BACKEND
:
924 if (copy_from_user(&backend
, argp
, sizeof backend
))
926 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
927 case VHOST_GET_FEATURES
:
928 features
= VHOST_NET_FEATURES
;
929 if (copy_to_user(featurep
, &features
, sizeof features
))
932 case VHOST_SET_FEATURES
:
933 if (copy_from_user(&features
, featurep
, sizeof features
))
935 if (features
& ~VHOST_NET_FEATURES
)
937 return vhost_net_set_features(n
, features
);
938 case VHOST_RESET_OWNER
:
939 return vhost_net_reset_owner(n
);
941 mutex_lock(&n
->dev
.mutex
);
942 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, arg
);
944 mutex_unlock(&n
->dev
.mutex
);
950 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
953 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
957 static const struct file_operations vhost_net_fops
= {
958 .owner
= THIS_MODULE
,
959 .release
= vhost_net_release
,
960 .unlocked_ioctl
= vhost_net_ioctl
,
962 .compat_ioctl
= vhost_net_compat_ioctl
,
964 .open
= vhost_net_open
,
965 .llseek
= noop_llseek
,
968 static struct miscdevice vhost_net_misc
= {
969 .minor
= VHOST_NET_MINOR
,
971 .fops
= &vhost_net_fops
,
974 static int vhost_net_init(void)
976 if (experimental_zcopytx
)
977 vhost_enable_zcopy(VHOST_NET_VQ_TX
);
978 return misc_register(&vhost_net_misc
);
980 module_init(vhost_net_init
);
982 static void vhost_net_exit(void)
984 misc_deregister(&vhost_net_misc
);
986 module_exit(vhost_net_exit
);
988 MODULE_VERSION("0.0.1");
989 MODULE_LICENSE("GPL v2");
990 MODULE_AUTHOR("Michael S. Tsirkin");
991 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
992 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
993 MODULE_ALIAS("devname:vhost-net");