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
{
73 /* refcount follows semantics similar to kref:
74 * 0: object is released
75 * 1: no outstanding ubufs
76 * >1: outstanding ubufs
79 wait_queue_head_t wait
;
80 struct vhost_virtqueue
*vq
;
83 struct vhost_net_virtqueue
{
84 struct vhost_virtqueue vq
;
85 /* hdr is used to store the virtio header.
86 * Since each iovec has >= 1 byte length, we never need more than
87 * header length entries to store the header. */
88 struct iovec hdr
[sizeof(struct virtio_net_hdr_mrg_rxbuf
)];
91 /* vhost zerocopy support fields below: */
92 /* last used idx for outstanding DMA zerocopy buffers */
94 /* first used idx for DMA done zerocopy buffers */
96 /* an array of userspace buffers info */
97 struct ubuf_info
*ubuf_info
;
98 /* Reference counting for outstanding ubufs.
99 * Protected by vq mutex. Writers must also take device mutex. */
100 struct vhost_net_ubuf_ref
*ubufs
;
104 struct vhost_dev dev
;
105 struct vhost_net_virtqueue vqs
[VHOST_NET_VQ_MAX
];
106 struct vhost_poll poll
[VHOST_NET_VQ_MAX
];
107 /* Number of TX recently submitted.
108 * Protected by tx vq lock. */
110 /* Number of times zerocopy TX recently failed.
111 * Protected by tx vq lock. */
112 unsigned tx_zcopy_err
;
113 /* Flush in progress. Protected by tx vq lock. */
117 static unsigned vhost_net_zcopy_mask __read_mostly
;
119 static void vhost_net_enable_zcopy(int vq
)
121 vhost_net_zcopy_mask
|= 0x1 << vq
;
124 static struct vhost_net_ubuf_ref
*
125 vhost_net_ubuf_alloc(struct vhost_virtqueue
*vq
, bool zcopy
)
127 struct vhost_net_ubuf_ref
*ubufs
;
128 /* No zero copy backend? Nothing to count. */
131 ubufs
= kmalloc(sizeof(*ubufs
), GFP_KERNEL
);
133 return ERR_PTR(-ENOMEM
);
134 atomic_set(&ubufs
->refcount
, 1);
135 init_waitqueue_head(&ubufs
->wait
);
140 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref
*ubufs
)
142 int r
= atomic_sub_return(1, &ubufs
->refcount
);
144 wake_up(&ubufs
->wait
);
148 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref
*ubufs
)
150 vhost_net_ubuf_put(ubufs
);
151 wait_event(ubufs
->wait
, !atomic_read(&ubufs
->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 void 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
;
297 add
= min(UIO_MAXIOV
- nvq
->done_idx
, j
);
298 vhost_add_used_and_signal_n(vq
->dev
, vq
,
299 &vq
->heads
[nvq
->done_idx
], add
);
300 nvq
->done_idx
= (nvq
->done_idx
+ add
) % UIO_MAXIOV
;
305 static void vhost_zerocopy_callback(struct ubuf_info
*ubuf
, bool success
)
307 struct vhost_net_ubuf_ref
*ubufs
= ubuf
->ctx
;
308 struct vhost_virtqueue
*vq
= ubufs
->vq
;
313 /* set len to mark this desc buffers done DMA */
314 vq
->heads
[ubuf
->desc
].len
= success
?
315 VHOST_DMA_DONE_LEN
: VHOST_DMA_FAILED_LEN
;
316 cnt
= vhost_net_ubuf_put(ubufs
);
319 * Trigger polling thread if guest stopped submitting new buffers:
320 * in this case, the refcount after decrement will eventually reach 1.
321 * We also trigger polling periodically after each 16 packets
322 * (the value 16 here is more or less arbitrary, it's tuned to trigger
323 * less than 10% of times).
325 if (cnt
<= 1 || !(cnt
% 16))
326 vhost_poll_queue(&vq
->poll
);
328 rcu_read_unlock_bh();
331 /* Expects to be always run from workqueue - which acts as
332 * read-size critical section for our kind of RCU. */
333 static void handle_tx(struct vhost_net
*net
)
335 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
336 struct vhost_virtqueue
*vq
= &nvq
->vq
;
339 struct msghdr msg
= {
345 .msg_flags
= MSG_DONTWAIT
,
347 size_t len
, total_len
= 0;
351 struct vhost_net_ubuf_ref
*uninitialized_var(ubufs
);
352 bool zcopy
, zcopy_used
;
354 mutex_lock(&vq
->mutex
);
355 sock
= vq
->private_data
;
359 vhost_disable_notify(&net
->dev
, vq
);
361 hdr_size
= nvq
->vhost_hlen
;
365 /* Release DMAs done buffers first */
367 vhost_zerocopy_signal_used(net
, vq
);
369 /* If more outstanding DMAs, queue the work.
370 * Handle upend_idx wrap around
372 if (unlikely((nvq
->upend_idx
+ vq
->num
- VHOST_MAX_PEND
)
373 % UIO_MAXIOV
== nvq
->done_idx
))
376 head
= vhost_get_vq_desc(&net
->dev
, vq
, vq
->iov
,
380 /* On error, stop handling until the next kick. */
381 if (unlikely(head
< 0))
383 /* Nothing new? Wait for eventfd to tell us they refilled. */
384 if (head
== vq
->num
) {
385 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
386 vhost_disable_notify(&net
->dev
, vq
);
392 vq_err(vq
, "Unexpected descriptor format for TX: "
393 "out %d, int %d\n", out
, in
);
396 /* Skip header. TODO: support TSO. */
397 s
= move_iovec_hdr(vq
->iov
, nvq
->hdr
, hdr_size
, out
);
398 msg
.msg_iovlen
= out
;
399 len
= iov_length(vq
->iov
, out
);
402 vq_err(vq
, "Unexpected header len for TX: "
403 "%zd expected %zd\n",
404 iov_length(nvq
->hdr
, s
), hdr_size
);
408 zcopy_used
= zcopy
&& len
>= VHOST_GOODCOPY_LEN
409 && (nvq
->upend_idx
+ 1) % UIO_MAXIOV
!=
411 && vhost_net_tx_select_zcopy(net
);
413 /* use msg_control to pass vhost zerocopy ubuf info to skb */
415 struct ubuf_info
*ubuf
;
416 ubuf
= nvq
->ubuf_info
+ nvq
->upend_idx
;
418 vq
->heads
[nvq
->upend_idx
].id
= head
;
419 vq
->heads
[nvq
->upend_idx
].len
= VHOST_DMA_IN_PROGRESS
;
420 ubuf
->callback
= vhost_zerocopy_callback
;
421 ubuf
->ctx
= nvq
->ubufs
;
422 ubuf
->desc
= nvq
->upend_idx
;
423 msg
.msg_control
= ubuf
;
424 msg
.msg_controllen
= sizeof(ubuf
);
426 atomic_inc(&ubufs
->refcount
);
427 nvq
->upend_idx
= (nvq
->upend_idx
+ 1) % UIO_MAXIOV
;
429 msg
.msg_control
= NULL
;
432 /* TODO: Check specific error and bomb out unless ENOBUFS? */
433 err
= sock
->ops
->sendmsg(NULL
, sock
, &msg
, len
);
434 if (unlikely(err
< 0)) {
436 vhost_net_ubuf_put(ubufs
);
437 nvq
->upend_idx
= ((unsigned)nvq
->upend_idx
- 1)
440 vhost_discard_vq_desc(vq
, 1);
444 pr_debug("Truncated TX packet: "
445 " len %d != %zd\n", err
, len
);
447 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
449 vhost_zerocopy_signal_used(net
, vq
);
451 vhost_net_tx_packet(net
);
452 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
453 vhost_poll_queue(&vq
->poll
);
458 mutex_unlock(&vq
->mutex
);
461 static int peek_head_len(struct sock
*sk
)
463 struct sk_buff
*head
;
467 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
468 head
= skb_peek(&sk
->sk_receive_queue
);
471 if (vlan_tx_tag_present(head
))
475 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
479 /* This is a multi-buffer version of vhost_get_desc, that works if
480 * vq has read descriptors only.
481 * @vq - the relevant virtqueue
482 * @datalen - data length we'll be reading
483 * @iovcount - returned count of io vectors we fill
485 * @log_num - log offset
486 * @quota - headcount quota, 1 for big buffer
487 * returns number of buffer heads allocated, negative on error
489 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
490 struct vring_used_elem
*heads
,
493 struct vhost_log
*log
,
497 unsigned int out
, in
;
503 while (datalen
> 0 && headcount
< quota
) {
504 if (unlikely(seg
>= UIO_MAXIOV
)) {
508 r
= vhost_get_vq_desc(vq
->dev
, vq
, vq
->iov
+ seg
,
509 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
519 if (unlikely(out
|| in
<= 0)) {
520 vq_err(vq
, "unexpected descriptor format for RX: "
521 "out %d, in %d\n", out
, in
);
529 heads
[headcount
].id
= d
;
530 heads
[headcount
].len
= iov_length(vq
->iov
+ seg
, in
);
531 datalen
-= heads
[headcount
].len
;
535 heads
[headcount
- 1].len
+= datalen
;
541 if (unlikely(datalen
> 0)) {
547 vhost_discard_vq_desc(vq
, headcount
);
551 /* Expects to be always run from workqueue - which acts as
552 * read-size critical section for our kind of RCU. */
553 static void handle_rx(struct vhost_net
*net
)
555 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
556 struct vhost_virtqueue
*vq
= &nvq
->vq
;
557 unsigned uninitialized_var(in
), log
;
558 struct vhost_log
*vq_log
;
559 struct msghdr msg
= {
562 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
565 .msg_flags
= MSG_DONTWAIT
,
567 struct virtio_net_hdr_mrg_rxbuf hdr
= {
569 .hdr
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
571 size_t total_len
= 0;
574 size_t vhost_hlen
, sock_hlen
;
575 size_t vhost_len
, sock_len
;
578 mutex_lock(&vq
->mutex
);
579 sock
= vq
->private_data
;
582 vhost_disable_notify(&net
->dev
, vq
);
584 vhost_hlen
= nvq
->vhost_hlen
;
585 sock_hlen
= nvq
->sock_hlen
;
587 vq_log
= unlikely(vhost_has_feature(&net
->dev
, VHOST_F_LOG_ALL
)) ?
589 mergeable
= vhost_has_feature(&net
->dev
, VIRTIO_NET_F_MRG_RXBUF
);
591 while ((sock_len
= peek_head_len(sock
->sk
))) {
592 sock_len
+= sock_hlen
;
593 vhost_len
= sock_len
+ vhost_hlen
;
594 headcount
= get_rx_bufs(vq
, vq
->heads
, vhost_len
,
596 likely(mergeable
) ? UIO_MAXIOV
: 1);
597 /* On error, stop handling until the next kick. */
598 if (unlikely(headcount
< 0))
600 /* On overrun, truncate and discard */
601 if (unlikely(headcount
> UIO_MAXIOV
)) {
603 err
= sock
->ops
->recvmsg(NULL
, sock
, &msg
,
604 1, MSG_DONTWAIT
| MSG_TRUNC
);
605 pr_debug("Discarded rx packet: len %zd\n", sock_len
);
608 /* OK, now we need to know about added descriptors. */
610 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
611 /* They have slipped one in as we were
612 * doing that: check again. */
613 vhost_disable_notify(&net
->dev
, vq
);
616 /* Nothing new? Wait for eventfd to tell us
620 /* We don't need to be notified again. */
621 if (unlikely((vhost_hlen
)))
622 /* Skip header. TODO: support TSO. */
623 move_iovec_hdr(vq
->iov
, nvq
->hdr
, vhost_hlen
, in
);
625 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
626 * needed because recvmsg can modify msg_iov. */
627 copy_iovec_hdr(vq
->iov
, nvq
->hdr
, sock_hlen
, in
);
629 err
= sock
->ops
->recvmsg(NULL
, sock
, &msg
,
630 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
631 /* Userspace might have consumed the packet meanwhile:
632 * it's not supposed to do this usually, but might be hard
633 * to prevent. Discard data we got (if any) and keep going. */
634 if (unlikely(err
!= sock_len
)) {
635 pr_debug("Discarded rx packet: "
636 " len %d, expected %zd\n", err
, sock_len
);
637 vhost_discard_vq_desc(vq
, headcount
);
640 if (unlikely(vhost_hlen
) &&
641 memcpy_toiovecend(nvq
->hdr
, (unsigned char *)&hdr
, 0,
643 vq_err(vq
, "Unable to write vnet_hdr at addr %p\n",
647 /* TODO: Should check and handle checksum. */
648 if (likely(mergeable
) &&
649 memcpy_toiovecend(nvq
->hdr
, (unsigned char *)&headcount
,
650 offsetof(typeof(hdr
), num_buffers
),
651 sizeof hdr
.num_buffers
)) {
652 vq_err(vq
, "Failed num_buffers write");
653 vhost_discard_vq_desc(vq
, headcount
);
656 vhost_add_used_and_signal_n(&net
->dev
, vq
, vq
->heads
,
658 if (unlikely(vq_log
))
659 vhost_log_write(vq
, vq_log
, log
, vhost_len
);
660 total_len
+= vhost_len
;
661 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
662 vhost_poll_queue(&vq
->poll
);
667 mutex_unlock(&vq
->mutex
);
670 static void handle_tx_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_rx_kick(struct vhost_work
*work
)
681 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
683 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
688 static void handle_tx_net(struct vhost_work
*work
)
690 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
691 poll
[VHOST_NET_VQ_TX
].work
);
695 static void handle_rx_net(struct vhost_work
*work
)
697 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
698 poll
[VHOST_NET_VQ_RX
].work
);
702 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
704 struct vhost_net
*n
= kmalloc(sizeof *n
, GFP_KERNEL
);
705 struct vhost_dev
*dev
;
706 struct vhost_virtqueue
**vqs
;
711 vqs
= kmalloc(VHOST_NET_VQ_MAX
* sizeof(*vqs
), GFP_KERNEL
);
718 vqs
[VHOST_NET_VQ_TX
] = &n
->vqs
[VHOST_NET_VQ_TX
].vq
;
719 vqs
[VHOST_NET_VQ_RX
] = &n
->vqs
[VHOST_NET_VQ_RX
].vq
;
720 n
->vqs
[VHOST_NET_VQ_TX
].vq
.handle_kick
= handle_tx_kick
;
721 n
->vqs
[VHOST_NET_VQ_RX
].vq
.handle_kick
= handle_rx_kick
;
722 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
723 n
->vqs
[i
].ubufs
= NULL
;
724 n
->vqs
[i
].ubuf_info
= NULL
;
725 n
->vqs
[i
].upend_idx
= 0;
726 n
->vqs
[i
].done_idx
= 0;
727 n
->vqs
[i
].vhost_hlen
= 0;
728 n
->vqs
[i
].sock_hlen
= 0;
730 vhost_dev_init(dev
, vqs
, VHOST_NET_VQ_MAX
);
732 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, POLLOUT
, dev
);
733 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, POLLIN
, dev
);
740 static void vhost_net_disable_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
);
746 if (!vq
->private_data
)
748 vhost_poll_stop(poll
);
751 static int vhost_net_enable_vq(struct vhost_net
*n
,
752 struct vhost_virtqueue
*vq
)
754 struct vhost_net_virtqueue
*nvq
=
755 container_of(vq
, struct vhost_net_virtqueue
, vq
);
756 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
759 sock
= vq
->private_data
;
763 return vhost_poll_start(poll
, sock
->file
);
766 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
767 struct vhost_virtqueue
*vq
)
771 mutex_lock(&vq
->mutex
);
772 sock
= vq
->private_data
;
773 vhost_net_disable_vq(n
, vq
);
774 vq
->private_data
= NULL
;
775 mutex_unlock(&vq
->mutex
);
779 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
780 struct socket
**rx_sock
)
782 *tx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_TX
].vq
);
783 *rx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_RX
].vq
);
786 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
788 vhost_poll_flush(n
->poll
+ index
);
789 vhost_poll_flush(&n
->vqs
[index
].vq
.poll
);
792 static void vhost_net_flush(struct vhost_net
*n
)
794 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
795 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
796 if (n
->vqs
[VHOST_NET_VQ_TX
].ubufs
) {
797 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
799 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
800 /* Wait for all lower device DMAs done. */
801 vhost_net_ubuf_put_and_wait(n
->vqs
[VHOST_NET_VQ_TX
].ubufs
);
802 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
804 atomic_set(&n
->vqs
[VHOST_NET_VQ_TX
].ubufs
->refcount
, 1);
805 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
809 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
811 struct vhost_net
*n
= f
->private_data
;
812 struct socket
*tx_sock
;
813 struct socket
*rx_sock
;
815 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
817 vhost_dev_stop(&n
->dev
);
818 vhost_dev_cleanup(&n
->dev
, false);
819 vhost_net_vq_reset(n
);
824 /* Make sure no callbacks are outstanding */
825 synchronize_rcu_bh();
826 /* We do an extra flush before freeing memory,
827 * since jobs can re-queue themselves. */
834 static struct socket
*get_raw_socket(int fd
)
837 struct sockaddr_ll sa
;
838 char buf
[MAX_ADDR_LEN
];
840 int uaddr_len
= sizeof uaddr
, r
;
841 struct socket
*sock
= sockfd_lookup(fd
, &r
);
844 return ERR_PTR(-ENOTSOCK
);
846 /* Parameter checking */
847 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
848 r
= -ESOCKTNOSUPPORT
;
852 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
,
857 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
867 static struct socket
*get_tap_socket(int fd
)
869 struct file
*file
= fget(fd
);
873 return ERR_PTR(-EBADF
);
874 sock
= tun_get_socket(file
);
877 sock
= macvtap_get_socket(file
);
883 static struct socket
*get_socket(int fd
)
887 /* special case to disable backend */
890 sock
= get_raw_socket(fd
);
893 sock
= get_tap_socket(fd
);
896 return ERR_PTR(-ENOTSOCK
);
899 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
901 struct socket
*sock
, *oldsock
;
902 struct vhost_virtqueue
*vq
;
903 struct vhost_net_virtqueue
*nvq
;
904 struct vhost_net_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
907 mutex_lock(&n
->dev
.mutex
);
908 r
= vhost_dev_check_owner(&n
->dev
);
912 if (index
>= VHOST_NET_VQ_MAX
) {
916 vq
= &n
->vqs
[index
].vq
;
917 nvq
= &n
->vqs
[index
];
918 mutex_lock(&vq
->mutex
);
920 /* Verify that ring has been setup correctly. */
921 if (!vhost_vq_access_ok(vq
)) {
925 sock
= get_socket(fd
);
931 /* start polling new socket */
932 oldsock
= vq
->private_data
;
933 if (sock
!= oldsock
) {
934 ubufs
= vhost_net_ubuf_alloc(vq
,
935 sock
&& vhost_sock_zcopy(sock
));
941 vhost_net_disable_vq(n
, vq
);
942 vq
->private_data
= sock
;
943 r
= vhost_init_used(vq
);
946 r
= vhost_net_enable_vq(n
, vq
);
950 oldubufs
= nvq
->ubufs
;
958 mutex_unlock(&vq
->mutex
);
961 vhost_net_ubuf_put_wait_and_free(oldubufs
);
962 mutex_lock(&vq
->mutex
);
963 vhost_zerocopy_signal_used(n
, vq
);
964 mutex_unlock(&vq
->mutex
);
968 vhost_net_flush_vq(n
, index
);
972 mutex_unlock(&n
->dev
.mutex
);
976 vq
->private_data
= oldsock
;
977 vhost_net_enable_vq(n
, vq
);
979 vhost_net_ubuf_put_wait_and_free(ubufs
);
983 mutex_unlock(&vq
->mutex
);
985 mutex_unlock(&n
->dev
.mutex
);
989 static long vhost_net_reset_owner(struct vhost_net
*n
)
991 struct socket
*tx_sock
= NULL
;
992 struct socket
*rx_sock
= NULL
;
994 struct vhost_memory
*memory
;
996 mutex_lock(&n
->dev
.mutex
);
997 err
= vhost_dev_check_owner(&n
->dev
);
1000 memory
= vhost_dev_reset_owner_prepare();
1005 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
1007 vhost_dev_reset_owner(&n
->dev
, memory
);
1008 vhost_net_vq_reset(n
);
1010 mutex_unlock(&n
->dev
.mutex
);
1012 sockfd_put(tx_sock
);
1014 sockfd_put(rx_sock
);
1018 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
1020 size_t vhost_hlen
, sock_hlen
, hdr_len
;
1023 hdr_len
= (features
& (1 << VIRTIO_NET_F_MRG_RXBUF
)) ?
1024 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
1025 sizeof(struct virtio_net_hdr
);
1026 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
1027 /* vhost provides vnet_hdr */
1028 vhost_hlen
= hdr_len
;
1031 /* socket provides vnet_hdr */
1033 sock_hlen
= hdr_len
;
1035 mutex_lock(&n
->dev
.mutex
);
1036 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
1037 !vhost_log_access_ok(&n
->dev
)) {
1038 mutex_unlock(&n
->dev
.mutex
);
1041 n
->dev
.acked_features
= features
;
1043 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
1044 mutex_lock(&n
->vqs
[i
].vq
.mutex
);
1045 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
1046 n
->vqs
[i
].sock_hlen
= sock_hlen
;
1047 mutex_unlock(&n
->vqs
[i
].vq
.mutex
);
1050 mutex_unlock(&n
->dev
.mutex
);
1054 static long vhost_net_set_owner(struct vhost_net
*n
)
1058 mutex_lock(&n
->dev
.mutex
);
1059 if (vhost_dev_has_owner(&n
->dev
)) {
1063 r
= vhost_net_set_ubuf_info(n
);
1066 r
= vhost_dev_set_owner(&n
->dev
);
1068 vhost_net_clear_ubuf_info(n
);
1071 mutex_unlock(&n
->dev
.mutex
);
1075 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
1078 struct vhost_net
*n
= f
->private_data
;
1079 void __user
*argp
= (void __user
*)arg
;
1080 u64 __user
*featurep
= argp
;
1081 struct vhost_vring_file backend
;
1086 case VHOST_NET_SET_BACKEND
:
1087 if (copy_from_user(&backend
, argp
, sizeof backend
))
1089 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
1090 case VHOST_GET_FEATURES
:
1091 features
= VHOST_NET_FEATURES
;
1092 if (copy_to_user(featurep
, &features
, sizeof features
))
1095 case VHOST_SET_FEATURES
:
1096 if (copy_from_user(&features
, featurep
, sizeof features
))
1098 if (features
& ~VHOST_NET_FEATURES
)
1100 return vhost_net_set_features(n
, features
);
1101 case VHOST_RESET_OWNER
:
1102 return vhost_net_reset_owner(n
);
1103 case VHOST_SET_OWNER
:
1104 return vhost_net_set_owner(n
);
1106 mutex_lock(&n
->dev
.mutex
);
1107 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, argp
);
1108 if (r
== -ENOIOCTLCMD
)
1109 r
= vhost_vring_ioctl(&n
->dev
, ioctl
, argp
);
1112 mutex_unlock(&n
->dev
.mutex
);
1117 #ifdef CONFIG_COMPAT
1118 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
1121 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
1125 static const struct file_operations vhost_net_fops
= {
1126 .owner
= THIS_MODULE
,
1127 .release
= vhost_net_release
,
1128 .unlocked_ioctl
= vhost_net_ioctl
,
1129 #ifdef CONFIG_COMPAT
1130 .compat_ioctl
= vhost_net_compat_ioctl
,
1132 .open
= vhost_net_open
,
1133 .llseek
= noop_llseek
,
1136 static struct miscdevice vhost_net_misc
= {
1137 .minor
= VHOST_NET_MINOR
,
1138 .name
= "vhost-net",
1139 .fops
= &vhost_net_fops
,
1142 static int vhost_net_init(void)
1144 if (experimental_zcopytx
)
1145 vhost_net_enable_zcopy(VHOST_NET_VQ_TX
);
1146 return misc_register(&vhost_net_misc
);
1148 module_init(vhost_net_init
);
1150 static void vhost_net_exit(void)
1152 misc_deregister(&vhost_net_misc
);
1154 module_exit(vhost_net_exit
);
1156 MODULE_VERSION("0.0.1");
1157 MODULE_LICENSE("GPL v2");
1158 MODULE_AUTHOR("Michael S. Tsirkin");
1159 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1160 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
1161 MODULE_ALIAS("devname:vhost-net");