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)
62 VHOST_NET_FEATURES
= VHOST_FEATURES
|
63 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR
) |
64 (1ULL << VIRTIO_NET_F_MRG_RXBUF
),
73 struct vhost_net_ubuf_ref
{
75 wait_queue_head_t wait
;
76 struct vhost_virtqueue
*vq
;
79 struct vhost_net_virtqueue
{
80 struct vhost_virtqueue vq
;
81 /* hdr is used to store the virtio header.
82 * Since each iovec has >= 1 byte length, we never need more than
83 * header length entries to store the header. */
84 struct iovec hdr
[sizeof(struct virtio_net_hdr_mrg_rxbuf
)];
87 /* vhost zerocopy support fields below: */
88 /* last used idx for outstanding DMA zerocopy buffers */
90 /* first used idx for DMA done zerocopy buffers */
92 /* an array of userspace buffers info */
93 struct ubuf_info
*ubuf_info
;
94 /* Reference counting for outstanding ubufs.
95 * Protected by vq mutex. Writers must also take device mutex. */
96 struct vhost_net_ubuf_ref
*ubufs
;
100 struct vhost_dev dev
;
101 struct vhost_net_virtqueue vqs
[VHOST_NET_VQ_MAX
];
102 struct vhost_poll poll
[VHOST_NET_VQ_MAX
];
103 /* Number of TX recently submitted.
104 * Protected by tx vq lock. */
106 /* Number of times zerocopy TX recently failed.
107 * Protected by tx vq lock. */
108 unsigned tx_zcopy_err
;
109 /* Flush in progress. Protected by tx vq lock. */
113 static unsigned vhost_net_zcopy_mask __read_mostly
;
115 static void vhost_net_enable_zcopy(int vq
)
117 vhost_net_zcopy_mask
|= 0x1 << vq
;
120 static void vhost_net_zerocopy_done_signal(struct kref
*kref
)
122 struct vhost_net_ubuf_ref
*ubufs
;
124 ubufs
= container_of(kref
, struct vhost_net_ubuf_ref
, kref
);
125 wake_up(&ubufs
->wait
);
128 static struct vhost_net_ubuf_ref
*
129 vhost_net_ubuf_alloc(struct vhost_virtqueue
*vq
, bool zcopy
)
131 struct vhost_net_ubuf_ref
*ubufs
;
132 /* No zero copy backend? Nothing to count. */
135 ubufs
= kmalloc(sizeof(*ubufs
), GFP_KERNEL
);
137 return ERR_PTR(-ENOMEM
);
138 kref_init(&ubufs
->kref
);
139 init_waitqueue_head(&ubufs
->wait
);
144 static void vhost_net_ubuf_put(struct vhost_net_ubuf_ref
*ubufs
)
146 kref_put(&ubufs
->kref
, vhost_net_zerocopy_done_signal
);
149 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref
*ubufs
)
151 kref_put(&ubufs
->kref
, vhost_net_zerocopy_done_signal
);
152 wait_event(ubufs
->wait
, !atomic_read(&ubufs
->kref
.refcount
));
156 static void vhost_net_clear_ubuf_info(struct vhost_net
*n
)
160 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
161 kfree(n
->vqs
[i
].ubuf_info
);
162 n
->vqs
[i
].ubuf_info
= NULL
;
166 int vhost_net_set_ubuf_info(struct vhost_net
*n
)
171 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
172 zcopy
= vhost_net_zcopy_mask
& (0x1 << i
);
175 n
->vqs
[i
].ubuf_info
= kmalloc(sizeof(*n
->vqs
[i
].ubuf_info
) *
176 UIO_MAXIOV
, GFP_KERNEL
);
177 if (!n
->vqs
[i
].ubuf_info
)
183 vhost_net_clear_ubuf_info(n
);
187 void vhost_net_vq_reset(struct vhost_net
*n
)
191 vhost_net_clear_ubuf_info(n
);
193 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
194 n
->vqs
[i
].done_idx
= 0;
195 n
->vqs
[i
].upend_idx
= 0;
196 n
->vqs
[i
].ubufs
= NULL
;
197 n
->vqs
[i
].vhost_hlen
= 0;
198 n
->vqs
[i
].sock_hlen
= 0;
203 static void vhost_net_tx_packet(struct vhost_net
*net
)
206 if (net
->tx_packets
< 1024)
209 net
->tx_zcopy_err
= 0;
212 static void vhost_net_tx_err(struct vhost_net
*net
)
217 static bool vhost_net_tx_select_zcopy(struct vhost_net
*net
)
219 /* TX flush waits for outstanding DMAs to be done.
220 * Don't start new DMAs.
222 return !net
->tx_flush
&&
223 net
->tx_packets
/ 64 >= net
->tx_zcopy_err
;
226 static bool vhost_sock_zcopy(struct socket
*sock
)
228 return unlikely(experimental_zcopytx
) &&
229 sock_flag(sock
->sk
, SOCK_ZEROCOPY
);
232 /* Pop first len bytes from iovec. Return number of segments used. */
233 static int move_iovec_hdr(struct iovec
*from
, struct iovec
*to
,
234 size_t len
, int iov_count
)
239 while (len
&& seg
< iov_count
) {
240 size
= min(from
->iov_len
, len
);
241 to
->iov_base
= from
->iov_base
;
243 from
->iov_len
-= size
;
244 from
->iov_base
+= size
;
252 /* Copy iovec entries for len bytes from iovec. */
253 static void copy_iovec_hdr(const struct iovec
*from
, struct iovec
*to
,
254 size_t len
, int iovcount
)
259 while (len
&& seg
< iovcount
) {
260 size
= min(from
->iov_len
, len
);
261 to
->iov_base
= from
->iov_base
;
270 /* In case of DMA done not in order in lower device driver for some reason.
271 * upend_idx is used to track end of used idx, done_idx is used to track head
272 * of used idx. Once lower device DMA done contiguously, we will signal KVM
275 static int vhost_zerocopy_signal_used(struct vhost_net
*net
,
276 struct vhost_virtqueue
*vq
)
278 struct vhost_net_virtqueue
*nvq
=
279 container_of(vq
, struct vhost_net_virtqueue
, vq
);
283 for (i
= nvq
->done_idx
; i
!= nvq
->upend_idx
; i
= (i
+ 1) % UIO_MAXIOV
) {
284 if (vq
->heads
[i
].len
== VHOST_DMA_FAILED_LEN
)
285 vhost_net_tx_err(net
);
286 if (VHOST_DMA_IS_DONE(vq
->heads
[i
].len
)) {
287 vq
->heads
[i
].len
= VHOST_DMA_CLEAR_LEN
;
288 vhost_add_used_and_signal(vq
->dev
, vq
,
299 static void vhost_zerocopy_callback(struct ubuf_info
*ubuf
, bool success
)
301 struct vhost_net_ubuf_ref
*ubufs
= ubuf
->ctx
;
302 struct vhost_virtqueue
*vq
= ubufs
->vq
;
303 int cnt
= atomic_read(&ubufs
->kref
.refcount
);
306 * Trigger polling thread if guest stopped submitting new buffers:
307 * in this case, the refcount after decrement will eventually reach 1
309 * We also trigger polling periodically after each 16 packets
310 * (the value 16 here is more or less arbitrary, it's tuned to trigger
311 * less than 10% of times).
313 if (cnt
<= 2 || !(cnt
% 16))
314 vhost_poll_queue(&vq
->poll
);
315 /* set len to mark this desc buffers done DMA */
316 vq
->heads
[ubuf
->desc
].len
= success
?
317 VHOST_DMA_DONE_LEN
: VHOST_DMA_FAILED_LEN
;
318 vhost_net_ubuf_put(ubufs
);
321 /* Expects to be always run from workqueue - which acts as
322 * read-size critical section for our kind of RCU. */
323 static void handle_tx(struct vhost_net
*net
)
325 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
326 struct vhost_virtqueue
*vq
= &nvq
->vq
;
329 struct msghdr msg
= {
335 .msg_flags
= MSG_DONTWAIT
,
337 size_t len
, total_len
= 0;
341 struct vhost_net_ubuf_ref
*uninitialized_var(ubufs
);
342 bool zcopy
, zcopy_used
;
344 /* TODO: check that we are running from vhost_worker? */
345 sock
= rcu_dereference_check(vq
->private_data
, 1);
349 mutex_lock(&vq
->mutex
);
350 vhost_disable_notify(&net
->dev
, vq
);
352 hdr_size
= nvq
->vhost_hlen
;
356 /* Release DMAs done buffers first */
358 vhost_zerocopy_signal_used(net
, vq
);
360 head
= vhost_get_vq_desc(&net
->dev
, vq
, vq
->iov
,
364 /* On error, stop handling until the next kick. */
365 if (unlikely(head
< 0))
367 /* Nothing new? Wait for eventfd to tell us they refilled. */
368 if (head
== vq
->num
) {
371 /* If more outstanding DMAs, queue the work.
372 * Handle upend_idx wrap around
374 num_pends
= likely(nvq
->upend_idx
>= nvq
->done_idx
) ?
375 (nvq
->upend_idx
- nvq
->done_idx
) :
376 (nvq
->upend_idx
+ UIO_MAXIOV
-
378 if (unlikely(num_pends
> VHOST_MAX_PEND
))
380 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
381 vhost_disable_notify(&net
->dev
, vq
);
387 vq_err(vq
, "Unexpected descriptor format for TX: "
388 "out %d, int %d\n", out
, in
);
391 /* Skip header. TODO: support TSO. */
392 s
= move_iovec_hdr(vq
->iov
, nvq
->hdr
, hdr_size
, out
);
393 msg
.msg_iovlen
= out
;
394 len
= iov_length(vq
->iov
, out
);
397 vq_err(vq
, "Unexpected header len for TX: "
398 "%zd expected %zd\n",
399 iov_length(nvq
->hdr
, s
), hdr_size
);
402 zcopy_used
= zcopy
&& (len
>= VHOST_GOODCOPY_LEN
||
403 nvq
->upend_idx
!= nvq
->done_idx
);
405 /* use msg_control to pass vhost zerocopy ubuf info to skb */
407 vq
->heads
[nvq
->upend_idx
].id
= head
;
408 if (!vhost_net_tx_select_zcopy(net
) ||
409 len
< VHOST_GOODCOPY_LEN
) {
410 /* copy don't need to wait for DMA done */
411 vq
->heads
[nvq
->upend_idx
].len
=
413 msg
.msg_control
= NULL
;
414 msg
.msg_controllen
= 0;
417 struct ubuf_info
*ubuf
;
418 ubuf
= nvq
->ubuf_info
+ nvq
->upend_idx
;
420 vq
->heads
[nvq
->upend_idx
].len
=
421 VHOST_DMA_IN_PROGRESS
;
422 ubuf
->callback
= vhost_zerocopy_callback
;
423 ubuf
->ctx
= nvq
->ubufs
;
424 ubuf
->desc
= nvq
->upend_idx
;
425 msg
.msg_control
= ubuf
;
426 msg
.msg_controllen
= sizeof(ubuf
);
428 kref_get(&ubufs
->kref
);
430 nvq
->upend_idx
= (nvq
->upend_idx
+ 1) % UIO_MAXIOV
;
432 msg
.msg_control
= NULL
;
433 /* TODO: Check specific error and bomb out unless ENOBUFS? */
434 err
= sock
->ops
->sendmsg(NULL
, sock
, &msg
, len
);
435 if (unlikely(err
< 0)) {
438 vhost_net_ubuf_put(ubufs
);
439 nvq
->upend_idx
= ((unsigned)nvq
->upend_idx
- 1)
442 vhost_discard_vq_desc(vq
, 1);
446 pr_debug("Truncated TX packet: "
447 " len %d != %zd\n", err
, len
);
449 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
451 vhost_zerocopy_signal_used(net
, vq
);
453 vhost_net_tx_packet(net
);
454 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
455 vhost_poll_queue(&vq
->poll
);
460 mutex_unlock(&vq
->mutex
);
463 static int peek_head_len(struct sock
*sk
)
465 struct sk_buff
*head
;
469 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
470 head
= skb_peek(&sk
->sk_receive_queue
);
473 if (vlan_tx_tag_present(head
))
477 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
481 /* This is a multi-buffer version of vhost_get_desc, that works if
482 * vq has read descriptors only.
483 * @vq - the relevant virtqueue
484 * @datalen - data length we'll be reading
485 * @iovcount - returned count of io vectors we fill
487 * @log_num - log offset
488 * @quota - headcount quota, 1 for big buffer
489 * returns number of buffer heads allocated, negative on error
491 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
492 struct vring_used_elem
*heads
,
495 struct vhost_log
*log
,
499 unsigned int out
, in
;
505 while (datalen
> 0 && headcount
< quota
) {
506 if (unlikely(seg
>= UIO_MAXIOV
)) {
510 d
= vhost_get_vq_desc(vq
->dev
, vq
, vq
->iov
+ seg
,
511 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
517 if (unlikely(out
|| in
<= 0)) {
518 vq_err(vq
, "unexpected descriptor format for RX: "
519 "out %d, in %d\n", out
, in
);
527 heads
[headcount
].id
= d
;
528 heads
[headcount
].len
= iov_length(vq
->iov
+ seg
, in
);
529 datalen
-= heads
[headcount
].len
;
533 heads
[headcount
- 1].len
+= datalen
;
539 vhost_discard_vq_desc(vq
, headcount
);
543 /* Expects to be always run from workqueue - which acts as
544 * read-size critical section for our kind of RCU. */
545 static void handle_rx(struct vhost_net
*net
)
547 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
548 struct vhost_virtqueue
*vq
= &nvq
->vq
;
549 unsigned uninitialized_var(in
), log
;
550 struct vhost_log
*vq_log
;
551 struct msghdr msg
= {
554 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
557 .msg_flags
= MSG_DONTWAIT
,
559 struct virtio_net_hdr_mrg_rxbuf hdr
= {
561 .hdr
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
563 size_t total_len
= 0;
566 size_t vhost_hlen
, sock_hlen
;
567 size_t vhost_len
, sock_len
;
568 /* TODO: check that we are running from vhost_worker? */
569 struct socket
*sock
= rcu_dereference_check(vq
->private_data
, 1);
574 mutex_lock(&vq
->mutex
);
575 vhost_disable_notify(&net
->dev
, vq
);
576 vhost_hlen
= nvq
->vhost_hlen
;
577 sock_hlen
= nvq
->sock_hlen
;
579 vq_log
= unlikely(vhost_has_feature(&net
->dev
, VHOST_F_LOG_ALL
)) ?
581 mergeable
= vhost_has_feature(&net
->dev
, VIRTIO_NET_F_MRG_RXBUF
);
583 while ((sock_len
= peek_head_len(sock
->sk
))) {
584 sock_len
+= sock_hlen
;
585 vhost_len
= sock_len
+ vhost_hlen
;
586 headcount
= get_rx_bufs(vq
, vq
->heads
, vhost_len
,
588 likely(mergeable
) ? UIO_MAXIOV
: 1);
589 /* On error, stop handling until the next kick. */
590 if (unlikely(headcount
< 0))
592 /* OK, now we need to know about added descriptors. */
594 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
595 /* They have slipped one in as we were
596 * doing that: check again. */
597 vhost_disable_notify(&net
->dev
, vq
);
600 /* Nothing new? Wait for eventfd to tell us
604 /* We don't need to be notified again. */
605 if (unlikely((vhost_hlen
)))
606 /* Skip header. TODO: support TSO. */
607 move_iovec_hdr(vq
->iov
, nvq
->hdr
, vhost_hlen
, in
);
609 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
610 * needed because recvmsg can modify msg_iov. */
611 copy_iovec_hdr(vq
->iov
, nvq
->hdr
, sock_hlen
, in
);
613 err
= sock
->ops
->recvmsg(NULL
, sock
, &msg
,
614 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
615 /* Userspace might have consumed the packet meanwhile:
616 * it's not supposed to do this usually, but might be hard
617 * to prevent. Discard data we got (if any) and keep going. */
618 if (unlikely(err
!= sock_len
)) {
619 pr_debug("Discarded rx packet: "
620 " len %d, expected %zd\n", err
, sock_len
);
621 vhost_discard_vq_desc(vq
, headcount
);
624 if (unlikely(vhost_hlen
) &&
625 memcpy_toiovecend(nvq
->hdr
, (unsigned char *)&hdr
, 0,
627 vq_err(vq
, "Unable to write vnet_hdr at addr %p\n",
631 /* TODO: Should check and handle checksum. */
632 if (likely(mergeable
) &&
633 memcpy_toiovecend(nvq
->hdr
, (unsigned char *)&headcount
,
634 offsetof(typeof(hdr
), num_buffers
),
635 sizeof hdr
.num_buffers
)) {
636 vq_err(vq
, "Failed num_buffers write");
637 vhost_discard_vq_desc(vq
, headcount
);
640 vhost_add_used_and_signal_n(&net
->dev
, vq
, vq
->heads
,
642 if (unlikely(vq_log
))
643 vhost_log_write(vq
, vq_log
, log
, vhost_len
);
644 total_len
+= vhost_len
;
645 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
646 vhost_poll_queue(&vq
->poll
);
651 mutex_unlock(&vq
->mutex
);
654 static void handle_tx_kick(struct vhost_work
*work
)
656 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
658 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
663 static void handle_rx_kick(struct vhost_work
*work
)
665 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
667 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
672 static void handle_tx_net(struct vhost_work
*work
)
674 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
675 poll
[VHOST_NET_VQ_TX
].work
);
679 static void handle_rx_net(struct vhost_work
*work
)
681 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
682 poll
[VHOST_NET_VQ_RX
].work
);
686 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
688 struct vhost_net
*n
= kmalloc(sizeof *n
, GFP_KERNEL
);
689 struct vhost_dev
*dev
;
690 struct vhost_virtqueue
**vqs
;
695 vqs
= kmalloc(VHOST_NET_VQ_MAX
* sizeof(*vqs
), GFP_KERNEL
);
702 vqs
[VHOST_NET_VQ_TX
] = &n
->vqs
[VHOST_NET_VQ_TX
].vq
;
703 vqs
[VHOST_NET_VQ_RX
] = &n
->vqs
[VHOST_NET_VQ_RX
].vq
;
704 n
->vqs
[VHOST_NET_VQ_TX
].vq
.handle_kick
= handle_tx_kick
;
705 n
->vqs
[VHOST_NET_VQ_RX
].vq
.handle_kick
= handle_rx_kick
;
706 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
707 n
->vqs
[i
].ubufs
= NULL
;
708 n
->vqs
[i
].ubuf_info
= NULL
;
709 n
->vqs
[i
].upend_idx
= 0;
710 n
->vqs
[i
].done_idx
= 0;
711 n
->vqs
[i
].vhost_hlen
= 0;
712 n
->vqs
[i
].sock_hlen
= 0;
714 r
= vhost_dev_init(dev
, vqs
, VHOST_NET_VQ_MAX
);
721 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, POLLOUT
, dev
);
722 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, POLLIN
, dev
);
729 static void vhost_net_disable_vq(struct vhost_net
*n
,
730 struct vhost_virtqueue
*vq
)
732 struct vhost_net_virtqueue
*nvq
=
733 container_of(vq
, struct vhost_net_virtqueue
, vq
);
734 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
735 if (!vq
->private_data
)
737 vhost_poll_stop(poll
);
740 static int vhost_net_enable_vq(struct vhost_net
*n
,
741 struct vhost_virtqueue
*vq
)
743 struct vhost_net_virtqueue
*nvq
=
744 container_of(vq
, struct vhost_net_virtqueue
, vq
);
745 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
748 sock
= rcu_dereference_protected(vq
->private_data
,
749 lockdep_is_held(&vq
->mutex
));
753 return vhost_poll_start(poll
, sock
->file
);
756 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
757 struct vhost_virtqueue
*vq
)
761 mutex_lock(&vq
->mutex
);
762 sock
= rcu_dereference_protected(vq
->private_data
,
763 lockdep_is_held(&vq
->mutex
));
764 vhost_net_disable_vq(n
, vq
);
765 rcu_assign_pointer(vq
->private_data
, NULL
);
766 mutex_unlock(&vq
->mutex
);
770 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
771 struct socket
**rx_sock
)
773 *tx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_TX
].vq
);
774 *rx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_RX
].vq
);
777 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
779 vhost_poll_flush(n
->poll
+ index
);
780 vhost_poll_flush(&n
->vqs
[index
].vq
.poll
);
783 static void vhost_net_flush(struct vhost_net
*n
)
785 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
786 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
787 if (n
->vqs
[VHOST_NET_VQ_TX
].ubufs
) {
788 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
790 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
791 /* Wait for all lower device DMAs done. */
792 vhost_net_ubuf_put_and_wait(n
->vqs
[VHOST_NET_VQ_TX
].ubufs
);
793 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
795 kref_init(&n
->vqs
[VHOST_NET_VQ_TX
].ubufs
->kref
);
796 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
800 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
802 struct vhost_net
*n
= f
->private_data
;
803 struct socket
*tx_sock
;
804 struct socket
*rx_sock
;
806 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
808 vhost_dev_stop(&n
->dev
);
809 vhost_dev_cleanup(&n
->dev
, false);
810 vhost_net_vq_reset(n
);
815 /* We do an extra flush before freeing memory,
816 * since jobs can re-queue themselves. */
823 static struct socket
*get_raw_socket(int fd
)
826 struct sockaddr_ll sa
;
827 char buf
[MAX_ADDR_LEN
];
829 int uaddr_len
= sizeof uaddr
, r
;
830 struct socket
*sock
= sockfd_lookup(fd
, &r
);
833 return ERR_PTR(-ENOTSOCK
);
835 /* Parameter checking */
836 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
837 r
= -ESOCKTNOSUPPORT
;
841 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
,
846 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
856 static struct socket
*get_tap_socket(int fd
)
858 struct file
*file
= fget(fd
);
862 return ERR_PTR(-EBADF
);
863 sock
= tun_get_socket(file
);
866 sock
= macvtap_get_socket(file
);
872 static struct socket
*get_socket(int fd
)
876 /* special case to disable backend */
879 sock
= get_raw_socket(fd
);
882 sock
= get_tap_socket(fd
);
885 return ERR_PTR(-ENOTSOCK
);
888 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
890 struct socket
*sock
, *oldsock
;
891 struct vhost_virtqueue
*vq
;
892 struct vhost_net_virtqueue
*nvq
;
893 struct vhost_net_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
896 mutex_lock(&n
->dev
.mutex
);
897 r
= vhost_dev_check_owner(&n
->dev
);
901 if (index
>= VHOST_NET_VQ_MAX
) {
905 vq
= &n
->vqs
[index
].vq
;
906 nvq
= &n
->vqs
[index
];
907 mutex_lock(&vq
->mutex
);
909 /* Verify that ring has been setup correctly. */
910 if (!vhost_vq_access_ok(vq
)) {
914 sock
= get_socket(fd
);
920 /* start polling new socket */
921 oldsock
= rcu_dereference_protected(vq
->private_data
,
922 lockdep_is_held(&vq
->mutex
));
923 if (sock
!= oldsock
) {
924 ubufs
= vhost_net_ubuf_alloc(vq
,
925 sock
&& vhost_sock_zcopy(sock
));
931 vhost_net_disable_vq(n
, vq
);
932 rcu_assign_pointer(vq
->private_data
, sock
);
933 r
= vhost_init_used(vq
);
936 r
= vhost_net_enable_vq(n
, vq
);
940 oldubufs
= nvq
->ubufs
;
948 mutex_unlock(&vq
->mutex
);
951 vhost_net_ubuf_put_and_wait(oldubufs
);
952 mutex_lock(&vq
->mutex
);
953 vhost_zerocopy_signal_used(n
, vq
);
954 mutex_unlock(&vq
->mutex
);
958 vhost_net_flush_vq(n
, index
);
962 mutex_unlock(&n
->dev
.mutex
);
966 rcu_assign_pointer(vq
->private_data
, oldsock
);
967 vhost_net_enable_vq(n
, vq
);
969 vhost_net_ubuf_put_and_wait(ubufs
);
973 mutex_unlock(&vq
->mutex
);
975 mutex_unlock(&n
->dev
.mutex
);
979 static long vhost_net_reset_owner(struct vhost_net
*n
)
981 struct socket
*tx_sock
= NULL
;
982 struct socket
*rx_sock
= NULL
;
984 struct vhost_memory
*memory
;
986 mutex_lock(&n
->dev
.mutex
);
987 err
= vhost_dev_check_owner(&n
->dev
);
990 memory
= vhost_dev_reset_owner_prepare();
995 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
997 vhost_dev_reset_owner(&n
->dev
, memory
);
998 vhost_net_vq_reset(n
);
1000 mutex_unlock(&n
->dev
.mutex
);
1002 fput(tx_sock
->file
);
1004 fput(rx_sock
->file
);
1008 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
1010 size_t vhost_hlen
, sock_hlen
, hdr_len
;
1013 hdr_len
= (features
& (1 << VIRTIO_NET_F_MRG_RXBUF
)) ?
1014 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
1015 sizeof(struct virtio_net_hdr
);
1016 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
1017 /* vhost provides vnet_hdr */
1018 vhost_hlen
= hdr_len
;
1021 /* socket provides vnet_hdr */
1023 sock_hlen
= hdr_len
;
1025 mutex_lock(&n
->dev
.mutex
);
1026 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
1027 !vhost_log_access_ok(&n
->dev
)) {
1028 mutex_unlock(&n
->dev
.mutex
);
1031 n
->dev
.acked_features
= features
;
1033 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
1034 mutex_lock(&n
->vqs
[i
].vq
.mutex
);
1035 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
1036 n
->vqs
[i
].sock_hlen
= sock_hlen
;
1037 mutex_unlock(&n
->vqs
[i
].vq
.mutex
);
1040 mutex_unlock(&n
->dev
.mutex
);
1044 static long vhost_net_set_owner(struct vhost_net
*n
)
1048 mutex_lock(&n
->dev
.mutex
);
1049 if (vhost_dev_has_owner(&n
->dev
)) {
1053 r
= vhost_net_set_ubuf_info(n
);
1056 r
= vhost_dev_set_owner(&n
->dev
);
1058 vhost_net_clear_ubuf_info(n
);
1061 mutex_unlock(&n
->dev
.mutex
);
1065 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
1068 struct vhost_net
*n
= f
->private_data
;
1069 void __user
*argp
= (void __user
*)arg
;
1070 u64 __user
*featurep
= argp
;
1071 struct vhost_vring_file backend
;
1076 case VHOST_NET_SET_BACKEND
:
1077 if (copy_from_user(&backend
, argp
, sizeof backend
))
1079 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
1080 case VHOST_GET_FEATURES
:
1081 features
= VHOST_NET_FEATURES
;
1082 if (copy_to_user(featurep
, &features
, sizeof features
))
1085 case VHOST_SET_FEATURES
:
1086 if (copy_from_user(&features
, featurep
, sizeof features
))
1088 if (features
& ~VHOST_NET_FEATURES
)
1090 return vhost_net_set_features(n
, features
);
1091 case VHOST_RESET_OWNER
:
1092 return vhost_net_reset_owner(n
);
1093 case VHOST_SET_OWNER
:
1094 return vhost_net_set_owner(n
);
1096 mutex_lock(&n
->dev
.mutex
);
1097 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, argp
);
1098 if (r
== -ENOIOCTLCMD
)
1099 r
= vhost_vring_ioctl(&n
->dev
, ioctl
, argp
);
1102 mutex_unlock(&n
->dev
.mutex
);
1107 #ifdef CONFIG_COMPAT
1108 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
1111 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
1115 static const struct file_operations vhost_net_fops
= {
1116 .owner
= THIS_MODULE
,
1117 .release
= vhost_net_release
,
1118 .unlocked_ioctl
= vhost_net_ioctl
,
1119 #ifdef CONFIG_COMPAT
1120 .compat_ioctl
= vhost_net_compat_ioctl
,
1122 .open
= vhost_net_open
,
1123 .llseek
= noop_llseek
,
1126 static struct miscdevice vhost_net_misc
= {
1127 .minor
= VHOST_NET_MINOR
,
1128 .name
= "vhost-net",
1129 .fops
= &vhost_net_fops
,
1132 static int vhost_net_init(void)
1134 if (experimental_zcopytx
)
1135 vhost_net_enable_zcopy(VHOST_NET_VQ_TX
);
1136 return misc_register(&vhost_net_misc
);
1138 module_init(vhost_net_init
);
1140 static void vhost_net_exit(void)
1142 misc_deregister(&vhost_net_misc
);
1144 module_exit(vhost_net_exit
);
1146 MODULE_VERSION("0.0.1");
1147 MODULE_LICENSE("GPL v2");
1148 MODULE_AUTHOR("Michael S. Tsirkin");
1149 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1150 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
1151 MODULE_ALIAS("devname:vhost-net");