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
)
162 for (i
= 0; i
< n
->dev
.nvqs
; ++i
) {
163 zcopy
= vhost_net_zcopy_mask
& (0x1 << i
);
165 kfree(n
->vqs
[i
].ubuf_info
);
169 int vhost_net_set_ubuf_info(struct vhost_net
*n
)
174 for (i
= 0; i
< n
->dev
.nvqs
; ++i
) {
175 zcopy
= vhost_net_zcopy_mask
& (0x1 << i
);
178 n
->vqs
[i
].ubuf_info
= kmalloc(sizeof(*n
->vqs
[i
].ubuf_info
) *
179 UIO_MAXIOV
, GFP_KERNEL
);
180 if (!n
->vqs
[i
].ubuf_info
)
187 zcopy
= vhost_net_zcopy_mask
& (0x1 << i
);
190 kfree(n
->vqs
[i
].ubuf_info
);
195 void vhost_net_vq_reset(struct vhost_net
*n
)
199 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
200 n
->vqs
[i
].done_idx
= 0;
201 n
->vqs
[i
].upend_idx
= 0;
202 n
->vqs
[i
].ubufs
= NULL
;
203 kfree(n
->vqs
[i
].ubuf_info
);
204 n
->vqs
[i
].ubuf_info
= NULL
;
205 n
->vqs
[i
].vhost_hlen
= 0;
206 n
->vqs
[i
].sock_hlen
= 0;
211 static void vhost_net_tx_packet(struct vhost_net
*net
)
214 if (net
->tx_packets
< 1024)
217 net
->tx_zcopy_err
= 0;
220 static void vhost_net_tx_err(struct vhost_net
*net
)
225 static bool vhost_net_tx_select_zcopy(struct vhost_net
*net
)
227 /* TX flush waits for outstanding DMAs to be done.
228 * Don't start new DMAs.
230 return !net
->tx_flush
&&
231 net
->tx_packets
/ 64 >= net
->tx_zcopy_err
;
234 static bool vhost_sock_zcopy(struct socket
*sock
)
236 return unlikely(experimental_zcopytx
) &&
237 sock_flag(sock
->sk
, SOCK_ZEROCOPY
);
240 /* Pop first len bytes from iovec. Return number of segments used. */
241 static int move_iovec_hdr(struct iovec
*from
, struct iovec
*to
,
242 size_t len
, int iov_count
)
247 while (len
&& seg
< iov_count
) {
248 size
= min(from
->iov_len
, len
);
249 to
->iov_base
= from
->iov_base
;
251 from
->iov_len
-= size
;
252 from
->iov_base
+= size
;
260 /* Copy iovec entries for len bytes from iovec. */
261 static void copy_iovec_hdr(const struct iovec
*from
, struct iovec
*to
,
262 size_t len
, int iovcount
)
267 while (len
&& seg
< iovcount
) {
268 size
= min(from
->iov_len
, len
);
269 to
->iov_base
= from
->iov_base
;
278 /* In case of DMA done not in order in lower device driver for some reason.
279 * upend_idx is used to track end of used idx, done_idx is used to track head
280 * of used idx. Once lower device DMA done contiguously, we will signal KVM
283 static int vhost_zerocopy_signal_used(struct vhost_net
*net
,
284 struct vhost_virtqueue
*vq
)
286 struct vhost_net_virtqueue
*nvq
=
287 container_of(vq
, struct vhost_net_virtqueue
, vq
);
291 for (i
= nvq
->done_idx
; i
!= nvq
->upend_idx
; i
= (i
+ 1) % UIO_MAXIOV
) {
292 if (vq
->heads
[i
].len
== VHOST_DMA_FAILED_LEN
)
293 vhost_net_tx_err(net
);
294 if (VHOST_DMA_IS_DONE(vq
->heads
[i
].len
)) {
295 vq
->heads
[i
].len
= VHOST_DMA_CLEAR_LEN
;
296 vhost_add_used_and_signal(vq
->dev
, vq
,
307 static void vhost_zerocopy_callback(struct ubuf_info
*ubuf
, bool success
)
309 struct vhost_net_ubuf_ref
*ubufs
= ubuf
->ctx
;
310 struct vhost_virtqueue
*vq
= ubufs
->vq
;
311 int cnt
= atomic_read(&ubufs
->kref
.refcount
);
314 * Trigger polling thread if guest stopped submitting new buffers:
315 * in this case, the refcount after decrement will eventually reach 1
317 * We also trigger polling periodically after each 16 packets
318 * (the value 16 here is more or less arbitrary, it's tuned to trigger
319 * less than 10% of times).
321 if (cnt
<= 2 || !(cnt
% 16))
322 vhost_poll_queue(&vq
->poll
);
323 /* set len to mark this desc buffers done DMA */
324 vq
->heads
[ubuf
->desc
].len
= success
?
325 VHOST_DMA_DONE_LEN
: VHOST_DMA_FAILED_LEN
;
326 vhost_net_ubuf_put(ubufs
);
329 /* Expects to be always run from workqueue - which acts as
330 * read-size critical section for our kind of RCU. */
331 static void handle_tx(struct vhost_net
*net
)
333 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
334 struct vhost_virtqueue
*vq
= &nvq
->vq
;
337 struct msghdr msg
= {
343 .msg_flags
= MSG_DONTWAIT
,
345 size_t len
, total_len
= 0;
349 struct vhost_net_ubuf_ref
*uninitialized_var(ubufs
);
350 bool zcopy
, zcopy_used
;
352 /* TODO: check that we are running from vhost_worker? */
353 sock
= rcu_dereference_check(vq
->private_data
, 1);
357 mutex_lock(&vq
->mutex
);
358 vhost_disable_notify(&net
->dev
, vq
);
360 hdr_size
= nvq
->vhost_hlen
;
364 /* Release DMAs done buffers first */
366 vhost_zerocopy_signal_used(net
, vq
);
368 head
= vhost_get_vq_desc(&net
->dev
, vq
, vq
->iov
,
372 /* On error, stop handling until the next kick. */
373 if (unlikely(head
< 0))
375 /* Nothing new? Wait for eventfd to tell us they refilled. */
376 if (head
== vq
->num
) {
379 /* If more outstanding DMAs, queue the work.
380 * Handle upend_idx wrap around
382 num_pends
= likely(nvq
->upend_idx
>= nvq
->done_idx
) ?
383 (nvq
->upend_idx
- nvq
->done_idx
) :
384 (nvq
->upend_idx
+ UIO_MAXIOV
-
386 if (unlikely(num_pends
> VHOST_MAX_PEND
))
388 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
389 vhost_disable_notify(&net
->dev
, vq
);
395 vq_err(vq
, "Unexpected descriptor format for TX: "
396 "out %d, int %d\n", out
, in
);
399 /* Skip header. TODO: support TSO. */
400 s
= move_iovec_hdr(vq
->iov
, nvq
->hdr
, hdr_size
, out
);
401 msg
.msg_iovlen
= out
;
402 len
= iov_length(vq
->iov
, out
);
405 vq_err(vq
, "Unexpected header len for TX: "
406 "%zd expected %zd\n",
407 iov_length(nvq
->hdr
, s
), hdr_size
);
410 zcopy_used
= zcopy
&& (len
>= VHOST_GOODCOPY_LEN
||
411 nvq
->upend_idx
!= nvq
->done_idx
);
413 /* use msg_control to pass vhost zerocopy ubuf info to skb */
415 vq
->heads
[nvq
->upend_idx
].id
= head
;
416 if (!vhost_net_tx_select_zcopy(net
) ||
417 len
< VHOST_GOODCOPY_LEN
) {
418 /* copy don't need to wait for DMA done */
419 vq
->heads
[nvq
->upend_idx
].len
=
421 msg
.msg_control
= NULL
;
422 msg
.msg_controllen
= 0;
425 struct ubuf_info
*ubuf
;
426 ubuf
= nvq
->ubuf_info
+ nvq
->upend_idx
;
428 vq
->heads
[nvq
->upend_idx
].len
=
429 VHOST_DMA_IN_PROGRESS
;
430 ubuf
->callback
= vhost_zerocopy_callback
;
431 ubuf
->ctx
= nvq
->ubufs
;
432 ubuf
->desc
= nvq
->upend_idx
;
433 msg
.msg_control
= ubuf
;
434 msg
.msg_controllen
= sizeof(ubuf
);
436 kref_get(&ubufs
->kref
);
438 nvq
->upend_idx
= (nvq
->upend_idx
+ 1) % UIO_MAXIOV
;
440 /* TODO: Check specific error and bomb out unless ENOBUFS? */
441 err
= sock
->ops
->sendmsg(NULL
, sock
, &msg
, len
);
442 if (unlikely(err
< 0)) {
445 vhost_net_ubuf_put(ubufs
);
446 nvq
->upend_idx
= ((unsigned)nvq
->upend_idx
- 1)
449 vhost_discard_vq_desc(vq
, 1);
453 pr_debug("Truncated TX packet: "
454 " len %d != %zd\n", err
, len
);
456 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
458 vhost_zerocopy_signal_used(net
, vq
);
460 vhost_net_tx_packet(net
);
461 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
462 vhost_poll_queue(&vq
->poll
);
467 mutex_unlock(&vq
->mutex
);
470 static int peek_head_len(struct sock
*sk
)
472 struct sk_buff
*head
;
476 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
477 head
= skb_peek(&sk
->sk_receive_queue
);
480 if (vlan_tx_tag_present(head
))
484 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
488 /* This is a multi-buffer version of vhost_get_desc, that works if
489 * vq has read descriptors only.
490 * @vq - the relevant virtqueue
491 * @datalen - data length we'll be reading
492 * @iovcount - returned count of io vectors we fill
494 * @log_num - log offset
495 * @quota - headcount quota, 1 for big buffer
496 * returns number of buffer heads allocated, negative on error
498 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
499 struct vring_used_elem
*heads
,
502 struct vhost_log
*log
,
506 unsigned int out
, in
;
512 while (datalen
> 0 && headcount
< quota
) {
513 if (unlikely(seg
>= UIO_MAXIOV
)) {
517 d
= vhost_get_vq_desc(vq
->dev
, vq
, vq
->iov
+ seg
,
518 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
524 if (unlikely(out
|| in
<= 0)) {
525 vq_err(vq
, "unexpected descriptor format for RX: "
526 "out %d, in %d\n", out
, in
);
534 heads
[headcount
].id
= d
;
535 heads
[headcount
].len
= iov_length(vq
->iov
+ seg
, in
);
536 datalen
-= heads
[headcount
].len
;
540 heads
[headcount
- 1].len
+= datalen
;
546 vhost_discard_vq_desc(vq
, headcount
);
550 /* Expects to be always run from workqueue - which acts as
551 * read-size critical section for our kind of RCU. */
552 static void handle_rx(struct vhost_net
*net
)
554 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
555 struct vhost_virtqueue
*vq
= &nvq
->vq
;
556 unsigned uninitialized_var(in
), log
;
557 struct vhost_log
*vq_log
;
558 struct msghdr msg
= {
561 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
564 .msg_flags
= MSG_DONTWAIT
,
566 struct virtio_net_hdr_mrg_rxbuf hdr
= {
568 .hdr
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
570 size_t total_len
= 0;
573 size_t vhost_hlen
, sock_hlen
;
574 size_t vhost_len
, sock_len
;
575 /* TODO: check that we are running from vhost_worker? */
576 struct socket
*sock
= rcu_dereference_check(vq
->private_data
, 1);
581 mutex_lock(&vq
->mutex
);
582 vhost_disable_notify(&net
->dev
, vq
);
583 vhost_hlen
= nvq
->vhost_hlen
;
584 sock_hlen
= nvq
->sock_hlen
;
586 vq_log
= unlikely(vhost_has_feature(&net
->dev
, VHOST_F_LOG_ALL
)) ?
588 mergeable
= vhost_has_feature(&net
->dev
, VIRTIO_NET_F_MRG_RXBUF
);
590 while ((sock_len
= peek_head_len(sock
->sk
))) {
591 sock_len
+= sock_hlen
;
592 vhost_len
= sock_len
+ vhost_hlen
;
593 headcount
= get_rx_bufs(vq
, vq
->heads
, vhost_len
,
595 likely(mergeable
) ? UIO_MAXIOV
: 1);
596 /* On error, stop handling until the next kick. */
597 if (unlikely(headcount
< 0))
599 /* OK, now we need to know about added descriptors. */
601 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
602 /* They have slipped one in as we were
603 * doing that: check again. */
604 vhost_disable_notify(&net
->dev
, vq
);
607 /* Nothing new? Wait for eventfd to tell us
611 /* We don't need to be notified again. */
612 if (unlikely((vhost_hlen
)))
613 /* Skip header. TODO: support TSO. */
614 move_iovec_hdr(vq
->iov
, nvq
->hdr
, vhost_hlen
, in
);
616 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
617 * needed because recvmsg can modify msg_iov. */
618 copy_iovec_hdr(vq
->iov
, nvq
->hdr
, sock_hlen
, in
);
620 err
= sock
->ops
->recvmsg(NULL
, sock
, &msg
,
621 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
622 /* Userspace might have consumed the packet meanwhile:
623 * it's not supposed to do this usually, but might be hard
624 * to prevent. Discard data we got (if any) and keep going. */
625 if (unlikely(err
!= sock_len
)) {
626 pr_debug("Discarded rx packet: "
627 " len %d, expected %zd\n", err
, sock_len
);
628 vhost_discard_vq_desc(vq
, headcount
);
631 if (unlikely(vhost_hlen
) &&
632 memcpy_toiovecend(nvq
->hdr
, (unsigned char *)&hdr
, 0,
634 vq_err(vq
, "Unable to write vnet_hdr at addr %p\n",
638 /* TODO: Should check and handle checksum. */
639 if (likely(mergeable
) &&
640 memcpy_toiovecend(nvq
->hdr
, (unsigned char *)&headcount
,
641 offsetof(typeof(hdr
), num_buffers
),
642 sizeof hdr
.num_buffers
)) {
643 vq_err(vq
, "Failed num_buffers write");
644 vhost_discard_vq_desc(vq
, headcount
);
647 vhost_add_used_and_signal_n(&net
->dev
, vq
, vq
->heads
,
649 if (unlikely(vq_log
))
650 vhost_log_write(vq
, vq_log
, log
, vhost_len
);
651 total_len
+= vhost_len
;
652 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
653 vhost_poll_queue(&vq
->poll
);
658 mutex_unlock(&vq
->mutex
);
661 static void handle_tx_kick(struct vhost_work
*work
)
663 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
665 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
670 static void handle_rx_kick(struct vhost_work
*work
)
672 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
674 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
679 static void handle_tx_net(struct vhost_work
*work
)
681 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
682 poll
[VHOST_NET_VQ_TX
].work
);
686 static void handle_rx_net(struct vhost_work
*work
)
688 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
689 poll
[VHOST_NET_VQ_RX
].work
);
693 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
695 struct vhost_net
*n
= kmalloc(sizeof *n
, GFP_KERNEL
);
696 struct vhost_dev
*dev
;
697 struct vhost_virtqueue
**vqs
;
702 vqs
= kmalloc(VHOST_NET_VQ_MAX
* sizeof(*vqs
), GFP_KERNEL
);
709 vqs
[VHOST_NET_VQ_TX
] = &n
->vqs
[VHOST_NET_VQ_TX
].vq
;
710 vqs
[VHOST_NET_VQ_RX
] = &n
->vqs
[VHOST_NET_VQ_RX
].vq
;
711 n
->vqs
[VHOST_NET_VQ_TX
].vq
.handle_kick
= handle_tx_kick
;
712 n
->vqs
[VHOST_NET_VQ_RX
].vq
.handle_kick
= handle_rx_kick
;
713 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
714 n
->vqs
[i
].ubufs
= NULL
;
715 n
->vqs
[i
].ubuf_info
= NULL
;
716 n
->vqs
[i
].upend_idx
= 0;
717 n
->vqs
[i
].done_idx
= 0;
718 n
->vqs
[i
].vhost_hlen
= 0;
719 n
->vqs
[i
].sock_hlen
= 0;
721 r
= vhost_dev_init(dev
, vqs
, VHOST_NET_VQ_MAX
);
728 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, POLLOUT
, dev
);
729 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, POLLIN
, dev
);
736 static void vhost_net_disable_vq(struct vhost_net
*n
,
737 struct vhost_virtqueue
*vq
)
739 struct vhost_net_virtqueue
*nvq
=
740 container_of(vq
, struct vhost_net_virtqueue
, vq
);
741 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
742 if (!vq
->private_data
)
744 vhost_poll_stop(poll
);
747 static int vhost_net_enable_vq(struct vhost_net
*n
,
748 struct vhost_virtqueue
*vq
)
750 struct vhost_net_virtqueue
*nvq
=
751 container_of(vq
, struct vhost_net_virtqueue
, vq
);
752 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
755 sock
= rcu_dereference_protected(vq
->private_data
,
756 lockdep_is_held(&vq
->mutex
));
760 return vhost_poll_start(poll
, sock
->file
);
763 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
764 struct vhost_virtqueue
*vq
)
768 mutex_lock(&vq
->mutex
);
769 sock
= rcu_dereference_protected(vq
->private_data
,
770 lockdep_is_held(&vq
->mutex
));
771 vhost_net_disable_vq(n
, vq
);
772 rcu_assign_pointer(vq
->private_data
, NULL
);
773 mutex_unlock(&vq
->mutex
);
777 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
778 struct socket
**rx_sock
)
780 *tx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_TX
].vq
);
781 *rx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_RX
].vq
);
784 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
786 vhost_poll_flush(n
->poll
+ index
);
787 vhost_poll_flush(&n
->vqs
[index
].vq
.poll
);
790 static void vhost_net_flush(struct vhost_net
*n
)
792 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
793 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
794 if (n
->vqs
[VHOST_NET_VQ_TX
].ubufs
) {
795 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
797 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
798 /* Wait for all lower device DMAs done. */
799 vhost_net_ubuf_put_and_wait(n
->vqs
[VHOST_NET_VQ_TX
].ubufs
);
800 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
802 kref_init(&n
->vqs
[VHOST_NET_VQ_TX
].ubufs
->kref
);
803 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
807 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
809 struct vhost_net
*n
= f
->private_data
;
810 struct socket
*tx_sock
;
811 struct socket
*rx_sock
;
813 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
815 vhost_dev_stop(&n
->dev
);
816 vhost_dev_cleanup(&n
->dev
, false);
817 vhost_net_vq_reset(n
);
822 /* We do an extra flush before freeing memory,
823 * since jobs can re-queue themselves. */
830 static struct socket
*get_raw_socket(int fd
)
833 struct sockaddr_ll sa
;
834 char buf
[MAX_ADDR_LEN
];
836 int uaddr_len
= sizeof uaddr
, r
;
837 struct socket
*sock
= sockfd_lookup(fd
, &r
);
840 return ERR_PTR(-ENOTSOCK
);
842 /* Parameter checking */
843 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
844 r
= -ESOCKTNOSUPPORT
;
848 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
,
853 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
863 static struct socket
*get_tap_socket(int fd
)
865 struct file
*file
= fget(fd
);
869 return ERR_PTR(-EBADF
);
870 sock
= tun_get_socket(file
);
873 sock
= macvtap_get_socket(file
);
879 static struct socket
*get_socket(int fd
)
883 /* special case to disable backend */
886 sock
= get_raw_socket(fd
);
889 sock
= get_tap_socket(fd
);
892 return ERR_PTR(-ENOTSOCK
);
895 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
897 struct socket
*sock
, *oldsock
;
898 struct vhost_virtqueue
*vq
;
899 struct vhost_net_virtqueue
*nvq
;
900 struct vhost_net_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
903 mutex_lock(&n
->dev
.mutex
);
904 r
= vhost_dev_check_owner(&n
->dev
);
908 if (index
>= VHOST_NET_VQ_MAX
) {
912 vq
= &n
->vqs
[index
].vq
;
913 nvq
= &n
->vqs
[index
];
914 mutex_lock(&vq
->mutex
);
916 /* Verify that ring has been setup correctly. */
917 if (!vhost_vq_access_ok(vq
)) {
921 sock
= get_socket(fd
);
927 /* start polling new socket */
928 oldsock
= rcu_dereference_protected(vq
->private_data
,
929 lockdep_is_held(&vq
->mutex
));
930 if (sock
!= oldsock
) {
931 ubufs
= vhost_net_ubuf_alloc(vq
,
932 sock
&& vhost_sock_zcopy(sock
));
938 vhost_net_disable_vq(n
, vq
);
939 rcu_assign_pointer(vq
->private_data
, sock
);
940 r
= vhost_init_used(vq
);
943 r
= vhost_net_enable_vq(n
, vq
);
947 oldubufs
= nvq
->ubufs
;
955 mutex_unlock(&vq
->mutex
);
958 vhost_net_ubuf_put_and_wait(oldubufs
);
959 mutex_lock(&vq
->mutex
);
960 vhost_zerocopy_signal_used(n
, vq
);
961 mutex_unlock(&vq
->mutex
);
965 vhost_net_flush_vq(n
, index
);
969 mutex_unlock(&n
->dev
.mutex
);
973 rcu_assign_pointer(vq
->private_data
, oldsock
);
974 vhost_net_enable_vq(n
, vq
);
976 vhost_net_ubuf_put_and_wait(ubufs
);
980 mutex_unlock(&vq
->mutex
);
982 mutex_unlock(&n
->dev
.mutex
);
986 static long vhost_net_reset_owner(struct vhost_net
*n
)
988 struct socket
*tx_sock
= NULL
;
989 struct socket
*rx_sock
= NULL
;
991 struct vhost_memory
*memory
;
993 mutex_lock(&n
->dev
.mutex
);
994 err
= vhost_dev_check_owner(&n
->dev
);
997 memory
= vhost_dev_reset_owner_prepare();
1002 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
1004 vhost_dev_reset_owner(&n
->dev
, memory
);
1005 vhost_net_vq_reset(n
);
1007 mutex_unlock(&n
->dev
.mutex
);
1009 fput(tx_sock
->file
);
1011 fput(rx_sock
->file
);
1015 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
1017 size_t vhost_hlen
, sock_hlen
, hdr_len
;
1020 hdr_len
= (features
& (1 << VIRTIO_NET_F_MRG_RXBUF
)) ?
1021 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
1022 sizeof(struct virtio_net_hdr
);
1023 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
1024 /* vhost provides vnet_hdr */
1025 vhost_hlen
= hdr_len
;
1028 /* socket provides vnet_hdr */
1030 sock_hlen
= hdr_len
;
1032 mutex_lock(&n
->dev
.mutex
);
1033 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
1034 !vhost_log_access_ok(&n
->dev
)) {
1035 mutex_unlock(&n
->dev
.mutex
);
1038 n
->dev
.acked_features
= features
;
1040 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
1041 mutex_lock(&n
->vqs
[i
].vq
.mutex
);
1042 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
1043 n
->vqs
[i
].sock_hlen
= sock_hlen
;
1044 mutex_unlock(&n
->vqs
[i
].vq
.mutex
);
1047 mutex_unlock(&n
->dev
.mutex
);
1051 static long vhost_net_set_owner(struct vhost_net
*n
)
1055 mutex_lock(&n
->dev
.mutex
);
1056 r
= vhost_net_set_ubuf_info(n
);
1059 r
= vhost_dev_set_owner(&n
->dev
);
1061 vhost_net_clear_ubuf_info(n
);
1064 mutex_unlock(&n
->dev
.mutex
);
1068 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
1071 struct vhost_net
*n
= f
->private_data
;
1072 void __user
*argp
= (void __user
*)arg
;
1073 u64 __user
*featurep
= argp
;
1074 struct vhost_vring_file backend
;
1079 case VHOST_NET_SET_BACKEND
:
1080 if (copy_from_user(&backend
, argp
, sizeof backend
))
1082 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
1083 case VHOST_GET_FEATURES
:
1084 features
= VHOST_NET_FEATURES
;
1085 if (copy_to_user(featurep
, &features
, sizeof features
))
1088 case VHOST_SET_FEATURES
:
1089 if (copy_from_user(&features
, featurep
, sizeof features
))
1091 if (features
& ~VHOST_NET_FEATURES
)
1093 return vhost_net_set_features(n
, features
);
1094 case VHOST_RESET_OWNER
:
1095 return vhost_net_reset_owner(n
);
1096 case VHOST_SET_OWNER
:
1097 return vhost_net_set_owner(n
);
1099 mutex_lock(&n
->dev
.mutex
);
1100 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, argp
);
1101 if (r
== -ENOIOCTLCMD
)
1102 r
= vhost_vring_ioctl(&n
->dev
, ioctl
, argp
);
1105 mutex_unlock(&n
->dev
.mutex
);
1110 #ifdef CONFIG_COMPAT
1111 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
1114 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
1118 static const struct file_operations vhost_net_fops
= {
1119 .owner
= THIS_MODULE
,
1120 .release
= vhost_net_release
,
1121 .unlocked_ioctl
= vhost_net_ioctl
,
1122 #ifdef CONFIG_COMPAT
1123 .compat_ioctl
= vhost_net_compat_ioctl
,
1125 .open
= vhost_net_open
,
1126 .llseek
= noop_llseek
,
1129 static struct miscdevice vhost_net_misc
= {
1130 .minor
= VHOST_NET_MINOR
,
1131 .name
= "vhost-net",
1132 .fops
= &vhost_net_fops
,
1135 static int vhost_net_init(void)
1137 if (experimental_zcopytx
)
1138 vhost_net_enable_zcopy(VHOST_NET_VQ_TX
);
1139 return misc_register(&vhost_net_misc
);
1141 module_init(vhost_net_init
);
1143 static void vhost_net_exit(void)
1145 misc_deregister(&vhost_net_misc
);
1147 module_exit(vhost_net_exit
);
1149 MODULE_VERSION("0.0.1");
1150 MODULE_LICENSE("GPL v2");
1151 MODULE_AUTHOR("Michael S. Tsirkin");
1152 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1153 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
1154 MODULE_ALIAS("devname:vhost-net");