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)
67 enum vhost_net_poll_state
{
68 VHOST_NET_POLL_DISABLED
= 0,
69 VHOST_NET_POLL_STARTED
= 1,
70 VHOST_NET_POLL_STOPPED
= 2,
75 struct vhost_virtqueue vqs
[VHOST_NET_VQ_MAX
];
76 struct vhost_poll poll
[VHOST_NET_VQ_MAX
];
77 /* Tells us whether we are polling a socket for TX.
78 * We only do this when socket buffer fills up.
79 * Protected by tx vq lock. */
80 enum vhost_net_poll_state tx_poll_state
;
81 /* Number of TX recently submitted.
82 * Protected by tx vq lock. */
84 /* Number of times zerocopy TX recently failed.
85 * Protected by tx vq lock. */
86 unsigned tx_zcopy_err
;
87 /* Flush in progress. Protected by tx vq lock. */
91 static void vhost_net_tx_packet(struct vhost_net
*net
)
94 if (net
->tx_packets
< 1024)
97 net
->tx_zcopy_err
= 0;
100 static void vhost_net_tx_err(struct vhost_net
*net
)
105 static bool vhost_net_tx_select_zcopy(struct vhost_net
*net
)
107 /* TX flush waits for outstanding DMAs to be done.
108 * Don't start new DMAs.
110 return !net
->tx_flush
&&
111 net
->tx_packets
/ 64 >= net
->tx_zcopy_err
;
114 static bool vhost_sock_zcopy(struct socket
*sock
)
116 return unlikely(experimental_zcopytx
) &&
117 sock_flag(sock
->sk
, SOCK_ZEROCOPY
);
120 /* Pop first len bytes from iovec. Return number of segments used. */
121 static int move_iovec_hdr(struct iovec
*from
, struct iovec
*to
,
122 size_t len
, int iov_count
)
127 while (len
&& seg
< iov_count
) {
128 size
= min(from
->iov_len
, len
);
129 to
->iov_base
= from
->iov_base
;
131 from
->iov_len
-= size
;
132 from
->iov_base
+= size
;
140 /* Copy iovec entries for len bytes from iovec. */
141 static void copy_iovec_hdr(const struct iovec
*from
, struct iovec
*to
,
142 size_t len
, int iovcount
)
147 while (len
&& seg
< iovcount
) {
148 size
= min(from
->iov_len
, len
);
149 to
->iov_base
= from
->iov_base
;
158 /* Caller must have TX VQ lock */
159 static void tx_poll_stop(struct vhost_net
*net
)
161 if (likely(net
->tx_poll_state
!= VHOST_NET_POLL_STARTED
))
163 vhost_poll_stop(net
->poll
+ VHOST_NET_VQ_TX
);
164 net
->tx_poll_state
= VHOST_NET_POLL_STOPPED
;
167 /* Caller must have TX VQ lock */
168 static void tx_poll_start(struct vhost_net
*net
, struct socket
*sock
)
170 if (unlikely(net
->tx_poll_state
!= VHOST_NET_POLL_STOPPED
))
172 vhost_poll_start(net
->poll
+ VHOST_NET_VQ_TX
, sock
->file
);
173 net
->tx_poll_state
= VHOST_NET_POLL_STARTED
;
176 /* In case of DMA done not in order in lower device driver for some reason.
177 * upend_idx is used to track end of used idx, done_idx is used to track head
178 * of used idx. Once lower device DMA done contiguously, we will signal KVM
181 static int vhost_zerocopy_signal_used(struct vhost_net
*net
,
182 struct vhost_virtqueue
*vq
)
187 for (i
= vq
->done_idx
; i
!= vq
->upend_idx
; i
= (i
+ 1) % UIO_MAXIOV
) {
188 if (vq
->heads
[i
].len
== VHOST_DMA_FAILED_LEN
)
189 vhost_net_tx_err(net
);
190 if (VHOST_DMA_IS_DONE(vq
->heads
[i
].len
)) {
191 vq
->heads
[i
].len
= VHOST_DMA_CLEAR_LEN
;
192 vhost_add_used_and_signal(vq
->dev
, vq
,
203 static void vhost_zerocopy_callback(struct ubuf_info
*ubuf
, bool success
)
205 struct vhost_ubuf_ref
*ubufs
= ubuf
->ctx
;
206 struct vhost_virtqueue
*vq
= ubufs
->vq
;
207 int cnt
= atomic_read(&ubufs
->kref
.refcount
);
210 * Trigger polling thread if guest stopped submitting new buffers:
211 * in this case, the refcount after decrement will eventually reach 1
213 * We also trigger polling periodically after each 16 packets
214 * (the value 16 here is more or less arbitrary, it's tuned to trigger
215 * less than 10% of times).
217 if (cnt
<= 2 || !(cnt
% 16))
218 vhost_poll_queue(&vq
->poll
);
219 /* set len to mark this desc buffers done DMA */
220 vq
->heads
[ubuf
->desc
].len
= success
?
221 VHOST_DMA_DONE_LEN
: VHOST_DMA_FAILED_LEN
;
222 vhost_ubuf_put(ubufs
);
225 /* Expects to be always run from workqueue - which acts as
226 * read-size critical section for our kind of RCU. */
227 static void handle_tx(struct vhost_net
*net
)
229 struct vhost_virtqueue
*vq
= &net
->dev
.vqs
[VHOST_NET_VQ_TX
];
232 struct msghdr msg
= {
238 .msg_flags
= MSG_DONTWAIT
,
240 size_t len
, total_len
= 0;
244 struct vhost_ubuf_ref
*uninitialized_var(ubufs
);
245 bool zcopy
, zcopy_used
;
247 /* TODO: check that we are running from vhost_worker? */
248 sock
= rcu_dereference_check(vq
->private_data
, 1);
252 wmem
= atomic_read(&sock
->sk
->sk_wmem_alloc
);
253 if (wmem
>= sock
->sk
->sk_sndbuf
) {
254 mutex_lock(&vq
->mutex
);
255 tx_poll_start(net
, sock
);
256 mutex_unlock(&vq
->mutex
);
260 mutex_lock(&vq
->mutex
);
261 vhost_disable_notify(&net
->dev
, vq
);
263 if (wmem
< sock
->sk
->sk_sndbuf
/ 2)
265 hdr_size
= vq
->vhost_hlen
;
269 /* Release DMAs done buffers first */
271 vhost_zerocopy_signal_used(net
, vq
);
273 head
= vhost_get_vq_desc(&net
->dev
, vq
, vq
->iov
,
277 /* On error, stop handling until the next kick. */
278 if (unlikely(head
< 0))
280 /* Nothing new? Wait for eventfd to tell us they refilled. */
281 if (head
== vq
->num
) {
284 wmem
= atomic_read(&sock
->sk
->sk_wmem_alloc
);
285 if (wmem
>= sock
->sk
->sk_sndbuf
* 3 / 4) {
286 tx_poll_start(net
, sock
);
287 set_bit(SOCK_ASYNC_NOSPACE
, &sock
->flags
);
290 /* If more outstanding DMAs, queue the work.
291 * Handle upend_idx wrap around
293 num_pends
= likely(vq
->upend_idx
>= vq
->done_idx
) ?
294 (vq
->upend_idx
- vq
->done_idx
) :
295 (vq
->upend_idx
+ UIO_MAXIOV
- vq
->done_idx
);
296 if (unlikely(num_pends
> VHOST_MAX_PEND
)) {
297 tx_poll_start(net
, sock
);
298 set_bit(SOCK_ASYNC_NOSPACE
, &sock
->flags
);
301 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
302 vhost_disable_notify(&net
->dev
, vq
);
308 vq_err(vq
, "Unexpected descriptor format for TX: "
309 "out %d, int %d\n", out
, in
);
312 /* Skip header. TODO: support TSO. */
313 s
= move_iovec_hdr(vq
->iov
, vq
->hdr
, hdr_size
, out
);
314 msg
.msg_iovlen
= out
;
315 len
= iov_length(vq
->iov
, out
);
318 vq_err(vq
, "Unexpected header len for TX: "
319 "%zd expected %zd\n",
320 iov_length(vq
->hdr
, s
), hdr_size
);
323 zcopy_used
= zcopy
&& (len
>= VHOST_GOODCOPY_LEN
||
324 vq
->upend_idx
!= vq
->done_idx
);
326 /* use msg_control to pass vhost zerocopy ubuf info to skb */
328 vq
->heads
[vq
->upend_idx
].id
= head
;
329 if (!vhost_net_tx_select_zcopy(net
) ||
330 len
< VHOST_GOODCOPY_LEN
) {
331 /* copy don't need to wait for DMA done */
332 vq
->heads
[vq
->upend_idx
].len
=
334 msg
.msg_control
= NULL
;
335 msg
.msg_controllen
= 0;
338 struct ubuf_info
*ubuf
= &vq
->ubuf_info
[head
];
340 vq
->heads
[vq
->upend_idx
].len
=
341 VHOST_DMA_IN_PROGRESS
;
342 ubuf
->callback
= vhost_zerocopy_callback
;
343 ubuf
->ctx
= vq
->ubufs
;
344 ubuf
->desc
= vq
->upend_idx
;
345 msg
.msg_control
= ubuf
;
346 msg
.msg_controllen
= sizeof(ubuf
);
348 kref_get(&ubufs
->kref
);
350 vq
->upend_idx
= (vq
->upend_idx
+ 1) % UIO_MAXIOV
;
352 /* TODO: Check specific error and bomb out unless ENOBUFS? */
353 err
= sock
->ops
->sendmsg(NULL
, sock
, &msg
, len
);
354 if (unlikely(err
< 0)) {
357 vhost_ubuf_put(ubufs
);
358 vq
->upend_idx
= ((unsigned)vq
->upend_idx
- 1) %
361 vhost_discard_vq_desc(vq
, 1);
362 if (err
== -EAGAIN
|| err
== -ENOBUFS
)
363 tx_poll_start(net
, sock
);
367 pr_debug("Truncated TX packet: "
368 " len %d != %zd\n", err
, len
);
370 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
372 vhost_zerocopy_signal_used(net
, vq
);
374 vhost_net_tx_packet(net
);
375 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
376 vhost_poll_queue(&vq
->poll
);
381 mutex_unlock(&vq
->mutex
);
384 static int peek_head_len(struct sock
*sk
)
386 struct sk_buff
*head
;
390 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
391 head
= skb_peek(&sk
->sk_receive_queue
);
394 if (vlan_tx_tag_present(head
))
398 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
402 /* This is a multi-buffer version of vhost_get_desc, that works if
403 * vq has read descriptors only.
404 * @vq - the relevant virtqueue
405 * @datalen - data length we'll be reading
406 * @iovcount - returned count of io vectors we fill
408 * @log_num - log offset
409 * @quota - headcount quota, 1 for big buffer
410 * returns number of buffer heads allocated, negative on error
412 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
413 struct vring_used_elem
*heads
,
416 struct vhost_log
*log
,
420 unsigned int out
, in
;
426 while (datalen
> 0 && headcount
< quota
) {
427 if (unlikely(seg
>= UIO_MAXIOV
)) {
431 d
= vhost_get_vq_desc(vq
->dev
, vq
, vq
->iov
+ seg
,
432 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
438 if (unlikely(out
|| in
<= 0)) {
439 vq_err(vq
, "unexpected descriptor format for RX: "
440 "out %d, in %d\n", out
, in
);
448 heads
[headcount
].id
= d
;
449 heads
[headcount
].len
= iov_length(vq
->iov
+ seg
, in
);
450 datalen
-= heads
[headcount
].len
;
454 heads
[headcount
- 1].len
+= datalen
;
460 vhost_discard_vq_desc(vq
, headcount
);
464 /* Expects to be always run from workqueue - which acts as
465 * read-size critical section for our kind of RCU. */
466 static void handle_rx(struct vhost_net
*net
)
468 struct vhost_virtqueue
*vq
= &net
->dev
.vqs
[VHOST_NET_VQ_RX
];
469 unsigned uninitialized_var(in
), log
;
470 struct vhost_log
*vq_log
;
471 struct msghdr msg
= {
474 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
477 .msg_flags
= MSG_DONTWAIT
,
479 struct virtio_net_hdr_mrg_rxbuf hdr
= {
481 .hdr
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
483 size_t total_len
= 0;
486 size_t vhost_hlen
, sock_hlen
;
487 size_t vhost_len
, sock_len
;
488 /* TODO: check that we are running from vhost_worker? */
489 struct socket
*sock
= rcu_dereference_check(vq
->private_data
, 1);
494 mutex_lock(&vq
->mutex
);
495 vhost_disable_notify(&net
->dev
, vq
);
496 vhost_hlen
= vq
->vhost_hlen
;
497 sock_hlen
= vq
->sock_hlen
;
499 vq_log
= unlikely(vhost_has_feature(&net
->dev
, VHOST_F_LOG_ALL
)) ?
501 mergeable
= vhost_has_feature(&net
->dev
, VIRTIO_NET_F_MRG_RXBUF
);
503 while ((sock_len
= peek_head_len(sock
->sk
))) {
504 sock_len
+= sock_hlen
;
505 vhost_len
= sock_len
+ vhost_hlen
;
506 headcount
= get_rx_bufs(vq
, vq
->heads
, vhost_len
,
508 likely(mergeable
) ? UIO_MAXIOV
: 1);
509 /* On error, stop handling until the next kick. */
510 if (unlikely(headcount
< 0))
512 /* OK, now we need to know about added descriptors. */
514 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
515 /* They have slipped one in as we were
516 * doing that: check again. */
517 vhost_disable_notify(&net
->dev
, vq
);
520 /* Nothing new? Wait for eventfd to tell us
524 /* We don't need to be notified again. */
525 if (unlikely((vhost_hlen
)))
526 /* Skip header. TODO: support TSO. */
527 move_iovec_hdr(vq
->iov
, vq
->hdr
, vhost_hlen
, in
);
529 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
530 * needed because recvmsg can modify msg_iov. */
531 copy_iovec_hdr(vq
->iov
, vq
->hdr
, sock_hlen
, in
);
533 err
= sock
->ops
->recvmsg(NULL
, sock
, &msg
,
534 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
535 /* Userspace might have consumed the packet meanwhile:
536 * it's not supposed to do this usually, but might be hard
537 * to prevent. Discard data we got (if any) and keep going. */
538 if (unlikely(err
!= sock_len
)) {
539 pr_debug("Discarded rx packet: "
540 " len %d, expected %zd\n", err
, sock_len
);
541 vhost_discard_vq_desc(vq
, headcount
);
544 if (unlikely(vhost_hlen
) &&
545 memcpy_toiovecend(vq
->hdr
, (unsigned char *)&hdr
, 0,
547 vq_err(vq
, "Unable to write vnet_hdr at addr %p\n",
551 /* TODO: Should check and handle checksum. */
552 if (likely(mergeable
) &&
553 memcpy_toiovecend(vq
->hdr
, (unsigned char *)&headcount
,
554 offsetof(typeof(hdr
), num_buffers
),
555 sizeof hdr
.num_buffers
)) {
556 vq_err(vq
, "Failed num_buffers write");
557 vhost_discard_vq_desc(vq
, headcount
);
560 vhost_add_used_and_signal_n(&net
->dev
, vq
, vq
->heads
,
562 if (unlikely(vq_log
))
563 vhost_log_write(vq
, vq_log
, log
, vhost_len
);
564 total_len
+= vhost_len
;
565 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
566 vhost_poll_queue(&vq
->poll
);
571 mutex_unlock(&vq
->mutex
);
574 static void handle_tx_kick(struct vhost_work
*work
)
576 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
578 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
583 static void handle_rx_kick(struct vhost_work
*work
)
585 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
587 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
592 static void handle_tx_net(struct vhost_work
*work
)
594 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
595 poll
[VHOST_NET_VQ_TX
].work
);
599 static void handle_rx_net(struct vhost_work
*work
)
601 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
602 poll
[VHOST_NET_VQ_RX
].work
);
606 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
608 struct vhost_net
*n
= kmalloc(sizeof *n
, GFP_KERNEL
);
609 struct vhost_dev
*dev
;
616 n
->vqs
[VHOST_NET_VQ_TX
].handle_kick
= handle_tx_kick
;
617 n
->vqs
[VHOST_NET_VQ_RX
].handle_kick
= handle_rx_kick
;
618 r
= vhost_dev_init(dev
, n
->vqs
, VHOST_NET_VQ_MAX
);
624 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, POLLOUT
, dev
);
625 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, POLLIN
, dev
);
626 n
->tx_poll_state
= VHOST_NET_POLL_DISABLED
;
633 static void vhost_net_disable_vq(struct vhost_net
*n
,
634 struct vhost_virtqueue
*vq
)
636 if (!vq
->private_data
)
638 if (vq
== n
->vqs
+ VHOST_NET_VQ_TX
) {
640 n
->tx_poll_state
= VHOST_NET_POLL_DISABLED
;
642 vhost_poll_stop(n
->poll
+ VHOST_NET_VQ_RX
);
645 static void vhost_net_enable_vq(struct vhost_net
*n
,
646 struct vhost_virtqueue
*vq
)
650 sock
= rcu_dereference_protected(vq
->private_data
,
651 lockdep_is_held(&vq
->mutex
));
654 if (vq
== n
->vqs
+ VHOST_NET_VQ_TX
) {
655 n
->tx_poll_state
= VHOST_NET_POLL_STOPPED
;
656 tx_poll_start(n
, sock
);
658 vhost_poll_start(n
->poll
+ VHOST_NET_VQ_RX
, sock
->file
);
661 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
662 struct vhost_virtqueue
*vq
)
666 mutex_lock(&vq
->mutex
);
667 sock
= rcu_dereference_protected(vq
->private_data
,
668 lockdep_is_held(&vq
->mutex
));
669 vhost_net_disable_vq(n
, vq
);
670 rcu_assign_pointer(vq
->private_data
, NULL
);
671 mutex_unlock(&vq
->mutex
);
675 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
676 struct socket
**rx_sock
)
678 *tx_sock
= vhost_net_stop_vq(n
, n
->vqs
+ VHOST_NET_VQ_TX
);
679 *rx_sock
= vhost_net_stop_vq(n
, n
->vqs
+ VHOST_NET_VQ_RX
);
682 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
684 vhost_poll_flush(n
->poll
+ index
);
685 vhost_poll_flush(&n
->dev
.vqs
[index
].poll
);
688 static void vhost_net_flush(struct vhost_net
*n
)
690 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
691 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
692 if (n
->dev
.vqs
[VHOST_NET_VQ_TX
].ubufs
) {
693 mutex_lock(&n
->dev
.vqs
[VHOST_NET_VQ_TX
].mutex
);
695 mutex_unlock(&n
->dev
.vqs
[VHOST_NET_VQ_TX
].mutex
);
696 /* Wait for all lower device DMAs done. */
697 vhost_ubuf_put_and_wait(n
->dev
.vqs
[VHOST_NET_VQ_TX
].ubufs
);
698 mutex_lock(&n
->dev
.vqs
[VHOST_NET_VQ_TX
].mutex
);
700 kref_init(&n
->dev
.vqs
[VHOST_NET_VQ_TX
].ubufs
->kref
);
701 mutex_unlock(&n
->dev
.vqs
[VHOST_NET_VQ_TX
].mutex
);
705 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
707 struct vhost_net
*n
= f
->private_data
;
708 struct socket
*tx_sock
;
709 struct socket
*rx_sock
;
711 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
713 vhost_dev_stop(&n
->dev
);
714 vhost_dev_cleanup(&n
->dev
, false);
719 /* We do an extra flush before freeing memory,
720 * since jobs can re-queue themselves. */
726 static struct socket
*get_raw_socket(int fd
)
729 struct sockaddr_ll sa
;
730 char buf
[MAX_ADDR_LEN
];
732 int uaddr_len
= sizeof uaddr
, r
;
733 struct socket
*sock
= sockfd_lookup(fd
, &r
);
736 return ERR_PTR(-ENOTSOCK
);
738 /* Parameter checking */
739 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
740 r
= -ESOCKTNOSUPPORT
;
744 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
,
749 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
759 static struct socket
*get_tap_socket(int fd
)
761 struct file
*file
= fget(fd
);
765 return ERR_PTR(-EBADF
);
766 sock
= tun_get_socket(file
);
769 sock
= macvtap_get_socket(file
);
775 static struct socket
*get_socket(int fd
)
779 /* special case to disable backend */
782 sock
= get_raw_socket(fd
);
785 sock
= get_tap_socket(fd
);
788 return ERR_PTR(-ENOTSOCK
);
791 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
793 struct socket
*sock
, *oldsock
;
794 struct vhost_virtqueue
*vq
;
795 struct vhost_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
798 mutex_lock(&n
->dev
.mutex
);
799 r
= vhost_dev_check_owner(&n
->dev
);
803 if (index
>= VHOST_NET_VQ_MAX
) {
808 mutex_lock(&vq
->mutex
);
810 /* Verify that ring has been setup correctly. */
811 if (!vhost_vq_access_ok(vq
)) {
815 sock
= get_socket(fd
);
821 /* start polling new socket */
822 oldsock
= rcu_dereference_protected(vq
->private_data
,
823 lockdep_is_held(&vq
->mutex
));
824 if (sock
!= oldsock
) {
825 ubufs
= vhost_ubuf_alloc(vq
, sock
&& vhost_sock_zcopy(sock
));
830 oldubufs
= vq
->ubufs
;
832 vhost_net_disable_vq(n
, vq
);
833 rcu_assign_pointer(vq
->private_data
, sock
);
834 vhost_net_enable_vq(n
, vq
);
836 r
= vhost_init_used(vq
);
845 mutex_unlock(&vq
->mutex
);
848 vhost_ubuf_put_and_wait(oldubufs
);
849 mutex_lock(&vq
->mutex
);
850 vhost_zerocopy_signal_used(n
, vq
);
851 mutex_unlock(&vq
->mutex
);
855 vhost_net_flush_vq(n
, index
);
859 mutex_unlock(&n
->dev
.mutex
);
865 mutex_unlock(&vq
->mutex
);
867 mutex_unlock(&n
->dev
.mutex
);
871 static long vhost_net_reset_owner(struct vhost_net
*n
)
873 struct socket
*tx_sock
= NULL
;
874 struct socket
*rx_sock
= NULL
;
877 mutex_lock(&n
->dev
.mutex
);
878 err
= vhost_dev_check_owner(&n
->dev
);
881 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
883 err
= vhost_dev_reset_owner(&n
->dev
);
885 mutex_unlock(&n
->dev
.mutex
);
893 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
895 size_t vhost_hlen
, sock_hlen
, hdr_len
;
898 hdr_len
= (features
& (1 << VIRTIO_NET_F_MRG_RXBUF
)) ?
899 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
900 sizeof(struct virtio_net_hdr
);
901 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
902 /* vhost provides vnet_hdr */
903 vhost_hlen
= hdr_len
;
906 /* socket provides vnet_hdr */
910 mutex_lock(&n
->dev
.mutex
);
911 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
912 !vhost_log_access_ok(&n
->dev
)) {
913 mutex_unlock(&n
->dev
.mutex
);
916 n
->dev
.acked_features
= features
;
918 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
919 mutex_lock(&n
->vqs
[i
].mutex
);
920 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
921 n
->vqs
[i
].sock_hlen
= sock_hlen
;
922 mutex_unlock(&n
->vqs
[i
].mutex
);
925 mutex_unlock(&n
->dev
.mutex
);
929 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
932 struct vhost_net
*n
= f
->private_data
;
933 void __user
*argp
= (void __user
*)arg
;
934 u64 __user
*featurep
= argp
;
935 struct vhost_vring_file backend
;
940 case VHOST_NET_SET_BACKEND
:
941 if (copy_from_user(&backend
, argp
, sizeof backend
))
943 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
944 case VHOST_GET_FEATURES
:
945 features
= VHOST_NET_FEATURES
;
946 if (copy_to_user(featurep
, &features
, sizeof features
))
949 case VHOST_SET_FEATURES
:
950 if (copy_from_user(&features
, featurep
, sizeof features
))
952 if (features
& ~VHOST_NET_FEATURES
)
954 return vhost_net_set_features(n
, features
);
955 case VHOST_RESET_OWNER
:
956 return vhost_net_reset_owner(n
);
958 mutex_lock(&n
->dev
.mutex
);
959 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, argp
);
960 if (r
== -ENOIOCTLCMD
)
961 r
= vhost_vring_ioctl(&n
->dev
, ioctl
, argp
);
964 mutex_unlock(&n
->dev
.mutex
);
970 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
973 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
977 static const struct file_operations vhost_net_fops
= {
978 .owner
= THIS_MODULE
,
979 .release
= vhost_net_release
,
980 .unlocked_ioctl
= vhost_net_ioctl
,
982 .compat_ioctl
= vhost_net_compat_ioctl
,
984 .open
= vhost_net_open
,
985 .llseek
= noop_llseek
,
988 static struct miscdevice vhost_net_misc
= {
989 .minor
= VHOST_NET_MINOR
,
991 .fops
= &vhost_net_fops
,
994 static int vhost_net_init(void)
996 if (experimental_zcopytx
)
997 vhost_enable_zcopy(VHOST_NET_VQ_TX
);
998 return misc_register(&vhost_net_misc
);
1000 module_init(vhost_net_init
);
1002 static void vhost_net_exit(void)
1004 misc_deregister(&vhost_net_misc
);
1006 module_exit(vhost_net_exit
);
1008 MODULE_VERSION("0.0.1");
1009 MODULE_LICENSE("GPL v2");
1010 MODULE_AUTHOR("Michael S. Tsirkin");
1011 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1012 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
1013 MODULE_ALIAS("devname:vhost-net");