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/file.h>
19 #include <linux/slab.h>
21 #include <linux/net.h>
22 #include <linux/if_packet.h>
23 #include <linux/if_arp.h>
24 #include <linux/if_tun.h>
25 #include <linux/if_macvlan.h>
26 #include <linux/if_vlan.h>
32 static int experimental_zcopytx
= 1;
33 module_param(experimental_zcopytx
, int, 0444);
34 MODULE_PARM_DESC(experimental_zcopytx
, "Enable Zero Copy TX;"
35 " 1 -Enable; 0 - Disable");
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)
61 VHOST_NET_FEATURES
= VHOST_FEATURES
|
62 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR
) |
63 (1ULL << VIRTIO_NET_F_MRG_RXBUF
),
72 struct vhost_net_ubuf_ref
{
74 wait_queue_head_t wait
;
75 struct vhost_virtqueue
*vq
;
78 struct vhost_net_virtqueue
{
79 struct vhost_virtqueue vq
;
80 /* hdr is used to store the virtio header.
81 * Since each iovec has >= 1 byte length, we never need more than
82 * header length entries to store the header. */
83 struct iovec hdr
[sizeof(struct virtio_net_hdr_mrg_rxbuf
)];
86 /* vhost zerocopy support fields below: */
87 /* last used idx for outstanding DMA zerocopy buffers */
89 /* first used idx for DMA done zerocopy buffers */
91 /* an array of userspace buffers info */
92 struct ubuf_info
*ubuf_info
;
93 /* Reference counting for outstanding ubufs.
94 * Protected by vq mutex. Writers must also take device mutex. */
95 struct vhost_net_ubuf_ref
*ubufs
;
100 struct vhost_net_virtqueue vqs
[VHOST_NET_VQ_MAX
];
101 struct vhost_poll poll
[VHOST_NET_VQ_MAX
];
102 /* Number of TX recently submitted.
103 * Protected by tx vq lock. */
105 /* Number of times zerocopy TX recently failed.
106 * Protected by tx vq lock. */
107 unsigned tx_zcopy_err
;
108 /* Flush in progress. Protected by tx vq lock. */
112 static unsigned vhost_net_zcopy_mask __read_mostly
;
114 static void vhost_net_enable_zcopy(int vq
)
116 vhost_net_zcopy_mask
|= 0x1 << vq
;
119 static void vhost_net_zerocopy_done_signal(struct kref
*kref
)
121 struct vhost_net_ubuf_ref
*ubufs
;
123 ubufs
= container_of(kref
, struct vhost_net_ubuf_ref
, kref
);
124 wake_up(&ubufs
->wait
);
127 static struct vhost_net_ubuf_ref
*
128 vhost_net_ubuf_alloc(struct vhost_virtqueue
*vq
, bool zcopy
)
130 struct vhost_net_ubuf_ref
*ubufs
;
131 /* No zero copy backend? Nothing to count. */
134 ubufs
= kmalloc(sizeof(*ubufs
), GFP_KERNEL
);
136 return ERR_PTR(-ENOMEM
);
137 kref_init(&ubufs
->kref
);
138 init_waitqueue_head(&ubufs
->wait
);
143 static void vhost_net_ubuf_put(struct vhost_net_ubuf_ref
*ubufs
)
145 kref_put(&ubufs
->kref
, vhost_net_zerocopy_done_signal
);
148 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref
*ubufs
)
150 kref_put(&ubufs
->kref
, vhost_net_zerocopy_done_signal
);
151 wait_event(ubufs
->wait
, !atomic_read(&ubufs
->kref
.refcount
));
154 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref
*ubufs
)
156 vhost_net_ubuf_put_and_wait(ubufs
);
160 static void vhost_net_clear_ubuf_info(struct vhost_net
*n
)
164 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
165 kfree(n
->vqs
[i
].ubuf_info
);
166 n
->vqs
[i
].ubuf_info
= NULL
;
170 static int vhost_net_set_ubuf_info(struct vhost_net
*n
)
175 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
176 zcopy
= vhost_net_zcopy_mask
& (0x1 << i
);
179 n
->vqs
[i
].ubuf_info
= kmalloc(sizeof(*n
->vqs
[i
].ubuf_info
) *
180 UIO_MAXIOV
, GFP_KERNEL
);
181 if (!n
->vqs
[i
].ubuf_info
)
187 vhost_net_clear_ubuf_info(n
);
191 static void vhost_net_vq_reset(struct vhost_net
*n
)
195 vhost_net_clear_ubuf_info(n
);
197 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
198 n
->vqs
[i
].done_idx
= 0;
199 n
->vqs
[i
].upend_idx
= 0;
200 n
->vqs
[i
].ubufs
= NULL
;
201 n
->vqs
[i
].vhost_hlen
= 0;
202 n
->vqs
[i
].sock_hlen
= 0;
207 static void vhost_net_tx_packet(struct vhost_net
*net
)
210 if (net
->tx_packets
< 1024)
213 net
->tx_zcopy_err
= 0;
216 static void vhost_net_tx_err(struct vhost_net
*net
)
221 static bool vhost_net_tx_select_zcopy(struct vhost_net
*net
)
223 /* TX flush waits for outstanding DMAs to be done.
224 * Don't start new DMAs.
226 return !net
->tx_flush
&&
227 net
->tx_packets
/ 64 >= net
->tx_zcopy_err
;
230 static bool vhost_sock_zcopy(struct socket
*sock
)
232 return unlikely(experimental_zcopytx
) &&
233 sock_flag(sock
->sk
, SOCK_ZEROCOPY
);
236 /* Pop first len bytes from iovec. Return number of segments used. */
237 static int move_iovec_hdr(struct iovec
*from
, struct iovec
*to
,
238 size_t len
, int iov_count
)
243 while (len
&& seg
< iov_count
) {
244 size
= min(from
->iov_len
, len
);
245 to
->iov_base
= from
->iov_base
;
247 from
->iov_len
-= size
;
248 from
->iov_base
+= size
;
256 /* Copy iovec entries for len bytes from iovec. */
257 static void copy_iovec_hdr(const struct iovec
*from
, struct iovec
*to
,
258 size_t len
, int iovcount
)
263 while (len
&& seg
< iovcount
) {
264 size
= min(from
->iov_len
, len
);
265 to
->iov_base
= from
->iov_base
;
274 /* In case of DMA done not in order in lower device driver for some reason.
275 * upend_idx is used to track end of used idx, done_idx is used to track head
276 * of used idx. Once lower device DMA done contiguously, we will signal KVM
279 static int vhost_zerocopy_signal_used(struct vhost_net
*net
,
280 struct vhost_virtqueue
*vq
)
282 struct vhost_net_virtqueue
*nvq
=
283 container_of(vq
, struct vhost_net_virtqueue
, vq
);
287 for (i
= nvq
->done_idx
; i
!= nvq
->upend_idx
; i
= (i
+ 1) % UIO_MAXIOV
) {
288 if (vq
->heads
[i
].len
== VHOST_DMA_FAILED_LEN
)
289 vhost_net_tx_err(net
);
290 if (VHOST_DMA_IS_DONE(vq
->heads
[i
].len
)) {
291 vq
->heads
[i
].len
= VHOST_DMA_CLEAR_LEN
;
292 vhost_add_used_and_signal(vq
->dev
, vq
,
303 static void vhost_zerocopy_callback(struct ubuf_info
*ubuf
, bool success
)
305 struct vhost_net_ubuf_ref
*ubufs
= ubuf
->ctx
;
306 struct vhost_virtqueue
*vq
= ubufs
->vq
;
307 int cnt
= atomic_read(&ubufs
->kref
.refcount
);
310 * Trigger polling thread if guest stopped submitting new buffers:
311 * in this case, the refcount after decrement will eventually reach 1
313 * We also trigger polling periodically after each 16 packets
314 * (the value 16 here is more or less arbitrary, it's tuned to trigger
315 * less than 10% of times).
317 if (cnt
<= 2 || !(cnt
% 16))
318 vhost_poll_queue(&vq
->poll
);
319 /* set len to mark this desc buffers done DMA */
320 vq
->heads
[ubuf
->desc
].len
= success
?
321 VHOST_DMA_DONE_LEN
: VHOST_DMA_FAILED_LEN
;
322 vhost_net_ubuf_put(ubufs
);
325 /* Expects to be always run from workqueue - which acts as
326 * read-size critical section for our kind of RCU. */
327 static void handle_tx(struct vhost_net
*net
)
329 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
330 struct vhost_virtqueue
*vq
= &nvq
->vq
;
333 struct msghdr msg
= {
339 .msg_flags
= MSG_DONTWAIT
,
341 size_t len
, total_len
= 0;
345 struct vhost_net_ubuf_ref
*uninitialized_var(ubufs
);
346 bool zcopy
, zcopy_used
;
348 mutex_lock(&vq
->mutex
);
349 sock
= vq
->private_data
;
353 vhost_disable_notify(&net
->dev
, vq
);
355 hdr_size
= nvq
->vhost_hlen
;
359 /* Release DMAs done buffers first */
361 vhost_zerocopy_signal_used(net
, vq
);
363 head
= vhost_get_vq_desc(&net
->dev
, vq
, vq
->iov
,
367 /* On error, stop handling until the next kick. */
368 if (unlikely(head
< 0))
370 /* Nothing new? Wait for eventfd to tell us they refilled. */
371 if (head
== vq
->num
) {
374 /* If more outstanding DMAs, queue the work.
375 * Handle upend_idx wrap around
377 num_pends
= likely(nvq
->upend_idx
>= nvq
->done_idx
) ?
378 (nvq
->upend_idx
- nvq
->done_idx
) :
379 (nvq
->upend_idx
+ UIO_MAXIOV
-
381 if (unlikely(num_pends
> VHOST_MAX_PEND
))
383 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
384 vhost_disable_notify(&net
->dev
, vq
);
390 vq_err(vq
, "Unexpected descriptor format for TX: "
391 "out %d, int %d\n", out
, in
);
394 /* Skip header. TODO: support TSO. */
395 s
= move_iovec_hdr(vq
->iov
, nvq
->hdr
, hdr_size
, out
);
396 msg
.msg_iovlen
= out
;
397 len
= iov_length(vq
->iov
, out
);
400 vq_err(vq
, "Unexpected header len for TX: "
401 "%zd expected %zd\n",
402 iov_length(nvq
->hdr
, s
), hdr_size
);
405 zcopy_used
= zcopy
&& (len
>= VHOST_GOODCOPY_LEN
||
406 nvq
->upend_idx
!= nvq
->done_idx
);
408 /* use msg_control to pass vhost zerocopy ubuf info to skb */
410 vq
->heads
[nvq
->upend_idx
].id
= head
;
411 if (!vhost_net_tx_select_zcopy(net
) ||
412 len
< VHOST_GOODCOPY_LEN
) {
413 /* copy don't need to wait for DMA done */
414 vq
->heads
[nvq
->upend_idx
].len
=
416 msg
.msg_control
= NULL
;
417 msg
.msg_controllen
= 0;
420 struct ubuf_info
*ubuf
;
421 ubuf
= nvq
->ubuf_info
+ nvq
->upend_idx
;
423 vq
->heads
[nvq
->upend_idx
].len
=
424 VHOST_DMA_IN_PROGRESS
;
425 ubuf
->callback
= vhost_zerocopy_callback
;
426 ubuf
->ctx
= nvq
->ubufs
;
427 ubuf
->desc
= nvq
->upend_idx
;
428 msg
.msg_control
= ubuf
;
429 msg
.msg_controllen
= sizeof(ubuf
);
431 kref_get(&ubufs
->kref
);
433 nvq
->upend_idx
= (nvq
->upend_idx
+ 1) % UIO_MAXIOV
;
435 msg
.msg_control
= NULL
;
436 /* TODO: Check specific error and bomb out unless ENOBUFS? */
437 err
= sock
->ops
->sendmsg(NULL
, sock
, &msg
, len
);
438 if (unlikely(err
< 0)) {
441 vhost_net_ubuf_put(ubufs
);
442 nvq
->upend_idx
= ((unsigned)nvq
->upend_idx
- 1)
445 vhost_discard_vq_desc(vq
, 1);
449 pr_debug("Truncated TX packet: "
450 " len %d != %zd\n", err
, len
);
452 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
454 vhost_zerocopy_signal_used(net
, vq
);
456 vhost_net_tx_packet(net
);
457 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
458 vhost_poll_queue(&vq
->poll
);
463 mutex_unlock(&vq
->mutex
);
466 static int peek_head_len(struct sock
*sk
)
468 struct sk_buff
*head
;
472 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
473 head
= skb_peek(&sk
->sk_receive_queue
);
476 if (vlan_tx_tag_present(head
))
480 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
484 /* This is a multi-buffer version of vhost_get_desc, that works if
485 * vq has read descriptors only.
486 * @vq - the relevant virtqueue
487 * @datalen - data length we'll be reading
488 * @iovcount - returned count of io vectors we fill
490 * @log_num - log offset
491 * @quota - headcount quota, 1 for big buffer
492 * returns number of buffer heads allocated, negative on error
494 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
495 struct vring_used_elem
*heads
,
498 struct vhost_log
*log
,
502 unsigned int out
, in
;
508 while (datalen
> 0 && headcount
< quota
) {
509 if (unlikely(seg
>= UIO_MAXIOV
)) {
513 d
= vhost_get_vq_desc(vq
->dev
, vq
, vq
->iov
+ seg
,
514 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
520 if (unlikely(out
|| in
<= 0)) {
521 vq_err(vq
, "unexpected descriptor format for RX: "
522 "out %d, in %d\n", out
, in
);
530 heads
[headcount
].id
= d
;
531 heads
[headcount
].len
= iov_length(vq
->iov
+ seg
, in
);
532 datalen
-= heads
[headcount
].len
;
536 heads
[headcount
- 1].len
+= datalen
;
542 vhost_discard_vq_desc(vq
, headcount
);
546 /* Expects to be always run from workqueue - which acts as
547 * read-size critical section for our kind of RCU. */
548 static void handle_rx(struct vhost_net
*net
)
550 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
551 struct vhost_virtqueue
*vq
= &nvq
->vq
;
552 unsigned uninitialized_var(in
), log
;
553 struct vhost_log
*vq_log
;
554 struct msghdr msg
= {
557 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
560 .msg_flags
= MSG_DONTWAIT
,
562 struct virtio_net_hdr_mrg_rxbuf hdr
= {
564 .hdr
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
566 size_t total_len
= 0;
569 size_t vhost_hlen
, sock_hlen
;
570 size_t vhost_len
, sock_len
;
573 mutex_lock(&vq
->mutex
);
574 sock
= vq
->private_data
;
577 vhost_disable_notify(&net
->dev
, vq
);
579 vhost_hlen
= nvq
->vhost_hlen
;
580 sock_hlen
= nvq
->sock_hlen
;
582 vq_log
= unlikely(vhost_has_feature(&net
->dev
, VHOST_F_LOG_ALL
)) ?
584 mergeable
= vhost_has_feature(&net
->dev
, VIRTIO_NET_F_MRG_RXBUF
);
586 while ((sock_len
= peek_head_len(sock
->sk
))) {
587 sock_len
+= sock_hlen
;
588 vhost_len
= sock_len
+ vhost_hlen
;
589 headcount
= get_rx_bufs(vq
, vq
->heads
, vhost_len
,
591 likely(mergeable
) ? UIO_MAXIOV
: 1);
592 /* On error, stop handling until the next kick. */
593 if (unlikely(headcount
< 0))
595 /* OK, now we need to know about added descriptors. */
597 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
598 /* They have slipped one in as we were
599 * doing that: check again. */
600 vhost_disable_notify(&net
->dev
, vq
);
603 /* Nothing new? Wait for eventfd to tell us
607 /* We don't need to be notified again. */
608 if (unlikely((vhost_hlen
)))
609 /* Skip header. TODO: support TSO. */
610 move_iovec_hdr(vq
->iov
, nvq
->hdr
, vhost_hlen
, in
);
612 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
613 * needed because recvmsg can modify msg_iov. */
614 copy_iovec_hdr(vq
->iov
, nvq
->hdr
, sock_hlen
, in
);
616 err
= sock
->ops
->recvmsg(NULL
, sock
, &msg
,
617 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
618 /* Userspace might have consumed the packet meanwhile:
619 * it's not supposed to do this usually, but might be hard
620 * to prevent. Discard data we got (if any) and keep going. */
621 if (unlikely(err
!= sock_len
)) {
622 pr_debug("Discarded rx packet: "
623 " len %d, expected %zd\n", err
, sock_len
);
624 vhost_discard_vq_desc(vq
, headcount
);
627 if (unlikely(vhost_hlen
) &&
628 memcpy_toiovecend(nvq
->hdr
, (unsigned char *)&hdr
, 0,
630 vq_err(vq
, "Unable to write vnet_hdr at addr %p\n",
634 /* TODO: Should check and handle checksum. */
635 if (likely(mergeable
) &&
636 memcpy_toiovecend(nvq
->hdr
, (unsigned char *)&headcount
,
637 offsetof(typeof(hdr
), num_buffers
),
638 sizeof hdr
.num_buffers
)) {
639 vq_err(vq
, "Failed num_buffers write");
640 vhost_discard_vq_desc(vq
, headcount
);
643 vhost_add_used_and_signal_n(&net
->dev
, vq
, vq
->heads
,
645 if (unlikely(vq_log
))
646 vhost_log_write(vq
, vq_log
, log
, vhost_len
);
647 total_len
+= vhost_len
;
648 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
649 vhost_poll_queue(&vq
->poll
);
654 mutex_unlock(&vq
->mutex
);
657 static void handle_tx_kick(struct vhost_work
*work
)
659 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
661 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
666 static void handle_rx_kick(struct vhost_work
*work
)
668 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
670 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
675 static void handle_tx_net(struct vhost_work
*work
)
677 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
678 poll
[VHOST_NET_VQ_TX
].work
);
682 static void handle_rx_net(struct vhost_work
*work
)
684 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
685 poll
[VHOST_NET_VQ_RX
].work
);
689 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
691 struct vhost_net
*n
= kmalloc(sizeof *n
, GFP_KERNEL
);
692 struct vhost_dev
*dev
;
693 struct vhost_virtqueue
**vqs
;
698 vqs
= kmalloc(VHOST_NET_VQ_MAX
* sizeof(*vqs
), GFP_KERNEL
);
705 vqs
[VHOST_NET_VQ_TX
] = &n
->vqs
[VHOST_NET_VQ_TX
].vq
;
706 vqs
[VHOST_NET_VQ_RX
] = &n
->vqs
[VHOST_NET_VQ_RX
].vq
;
707 n
->vqs
[VHOST_NET_VQ_TX
].vq
.handle_kick
= handle_tx_kick
;
708 n
->vqs
[VHOST_NET_VQ_RX
].vq
.handle_kick
= handle_rx_kick
;
709 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
710 n
->vqs
[i
].ubufs
= NULL
;
711 n
->vqs
[i
].ubuf_info
= NULL
;
712 n
->vqs
[i
].upend_idx
= 0;
713 n
->vqs
[i
].done_idx
= 0;
714 n
->vqs
[i
].vhost_hlen
= 0;
715 n
->vqs
[i
].sock_hlen
= 0;
717 r
= vhost_dev_init(dev
, vqs
, VHOST_NET_VQ_MAX
);
724 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, POLLOUT
, dev
);
725 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, POLLIN
, dev
);
732 static void vhost_net_disable_vq(struct vhost_net
*n
,
733 struct vhost_virtqueue
*vq
)
735 struct vhost_net_virtqueue
*nvq
=
736 container_of(vq
, struct vhost_net_virtqueue
, vq
);
737 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
738 if (!vq
->private_data
)
740 vhost_poll_stop(poll
);
743 static int vhost_net_enable_vq(struct vhost_net
*n
,
744 struct vhost_virtqueue
*vq
)
746 struct vhost_net_virtqueue
*nvq
=
747 container_of(vq
, struct vhost_net_virtqueue
, vq
);
748 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
751 sock
= vq
->private_data
;
755 return vhost_poll_start(poll
, sock
->file
);
758 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
759 struct vhost_virtqueue
*vq
)
763 mutex_lock(&vq
->mutex
);
764 sock
= vq
->private_data
;
765 vhost_net_disable_vq(n
, vq
);
766 vq
->private_data
= NULL
;
767 mutex_unlock(&vq
->mutex
);
771 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
772 struct socket
**rx_sock
)
774 *tx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_TX
].vq
);
775 *rx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_RX
].vq
);
778 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
780 vhost_poll_flush(n
->poll
+ index
);
781 vhost_poll_flush(&n
->vqs
[index
].vq
.poll
);
784 static void vhost_net_flush(struct vhost_net
*n
)
786 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
787 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
788 if (n
->vqs
[VHOST_NET_VQ_TX
].ubufs
) {
789 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
791 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
792 /* Wait for all lower device DMAs done. */
793 vhost_net_ubuf_put_and_wait(n
->vqs
[VHOST_NET_VQ_TX
].ubufs
);
794 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
796 kref_init(&n
->vqs
[VHOST_NET_VQ_TX
].ubufs
->kref
);
797 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
801 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
803 struct vhost_net
*n
= f
->private_data
;
804 struct socket
*tx_sock
;
805 struct socket
*rx_sock
;
807 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
809 vhost_dev_stop(&n
->dev
);
810 vhost_dev_cleanup(&n
->dev
, false);
811 vhost_net_vq_reset(n
);
816 /* We do an extra flush before freeing memory,
817 * since jobs can re-queue themselves. */
824 static struct socket
*get_raw_socket(int fd
)
827 struct sockaddr_ll sa
;
828 char buf
[MAX_ADDR_LEN
];
830 int uaddr_len
= sizeof uaddr
, r
;
831 struct socket
*sock
= sockfd_lookup(fd
, &r
);
834 return ERR_PTR(-ENOTSOCK
);
836 /* Parameter checking */
837 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
838 r
= -ESOCKTNOSUPPORT
;
842 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
,
847 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
857 static struct socket
*get_tap_socket(int fd
)
859 struct file
*file
= fget(fd
);
863 return ERR_PTR(-EBADF
);
864 sock
= tun_get_socket(file
);
867 sock
= macvtap_get_socket(file
);
873 static struct socket
*get_socket(int fd
)
877 /* special case to disable backend */
880 sock
= get_raw_socket(fd
);
883 sock
= get_tap_socket(fd
);
886 return ERR_PTR(-ENOTSOCK
);
889 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
891 struct socket
*sock
, *oldsock
;
892 struct vhost_virtqueue
*vq
;
893 struct vhost_net_virtqueue
*nvq
;
894 struct vhost_net_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
897 mutex_lock(&n
->dev
.mutex
);
898 r
= vhost_dev_check_owner(&n
->dev
);
902 if (index
>= VHOST_NET_VQ_MAX
) {
906 vq
= &n
->vqs
[index
].vq
;
907 nvq
= &n
->vqs
[index
];
908 mutex_lock(&vq
->mutex
);
910 /* Verify that ring has been setup correctly. */
911 if (!vhost_vq_access_ok(vq
)) {
915 sock
= get_socket(fd
);
921 /* start polling new socket */
922 oldsock
= vq
->private_data
;
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 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_wait_and_free(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 vq
->private_data
= oldsock
;
967 vhost_net_enable_vq(n
, vq
);
969 vhost_net_ubuf_put_wait_and_free(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");