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>
20 #include <linux/vmalloc.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 ((__force __virtio32)3)
52 /* Lower device DMA done */
53 #define VHOST_DMA_DONE_LEN ((__force __virtio32)2)
54 /* Lower device DMA in progress */
55 #define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1)
57 #define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0)
59 #define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)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
) |
65 (1ULL << VIRTIO_F_VERSION_1
),
74 struct vhost_net_ubuf_ref
{
75 /* refcount follows semantics similar to kref:
76 * 0: object is released
77 * 1: no outstanding ubufs
78 * >1: outstanding ubufs
81 wait_queue_head_t wait
;
82 struct vhost_virtqueue
*vq
;
85 struct vhost_net_virtqueue
{
86 struct vhost_virtqueue vq
;
89 /* vhost zerocopy support fields below: */
90 /* last used idx for outstanding DMA zerocopy buffers */
92 /* first used idx for DMA done zerocopy buffers */
94 /* an array of userspace buffers info */
95 struct ubuf_info
*ubuf_info
;
96 /* Reference counting for outstanding ubufs.
97 * Protected by vq mutex. Writers must also take device mutex. */
98 struct vhost_net_ubuf_ref
*ubufs
;
102 struct vhost_dev dev
;
103 struct vhost_net_virtqueue vqs
[VHOST_NET_VQ_MAX
];
104 struct vhost_poll poll
[VHOST_NET_VQ_MAX
];
105 /* Number of TX recently submitted.
106 * Protected by tx vq lock. */
108 /* Number of times zerocopy TX recently failed.
109 * Protected by tx vq lock. */
110 unsigned tx_zcopy_err
;
111 /* Flush in progress. Protected by tx vq lock. */
115 static unsigned vhost_net_zcopy_mask __read_mostly
;
117 static void vhost_net_enable_zcopy(int vq
)
119 vhost_net_zcopy_mask
|= 0x1 << vq
;
122 static struct vhost_net_ubuf_ref
*
123 vhost_net_ubuf_alloc(struct vhost_virtqueue
*vq
, bool zcopy
)
125 struct vhost_net_ubuf_ref
*ubufs
;
126 /* No zero copy backend? Nothing to count. */
129 ubufs
= kmalloc(sizeof(*ubufs
), GFP_KERNEL
);
131 return ERR_PTR(-ENOMEM
);
132 atomic_set(&ubufs
->refcount
, 1);
133 init_waitqueue_head(&ubufs
->wait
);
138 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref
*ubufs
)
140 int r
= atomic_sub_return(1, &ubufs
->refcount
);
142 wake_up(&ubufs
->wait
);
146 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref
*ubufs
)
148 vhost_net_ubuf_put(ubufs
);
149 wait_event(ubufs
->wait
, !atomic_read(&ubufs
->refcount
));
152 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref
*ubufs
)
154 vhost_net_ubuf_put_and_wait(ubufs
);
158 static void vhost_net_clear_ubuf_info(struct vhost_net
*n
)
162 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
163 kfree(n
->vqs
[i
].ubuf_info
);
164 n
->vqs
[i
].ubuf_info
= NULL
;
168 static int vhost_net_set_ubuf_info(struct vhost_net
*n
)
173 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
174 zcopy
= vhost_net_zcopy_mask
& (0x1 << i
);
177 n
->vqs
[i
].ubuf_info
= kmalloc(sizeof(*n
->vqs
[i
].ubuf_info
) *
178 UIO_MAXIOV
, GFP_KERNEL
);
179 if (!n
->vqs
[i
].ubuf_info
)
185 vhost_net_clear_ubuf_info(n
);
189 static void vhost_net_vq_reset(struct vhost_net
*n
)
193 vhost_net_clear_ubuf_info(n
);
195 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
196 n
->vqs
[i
].done_idx
= 0;
197 n
->vqs
[i
].upend_idx
= 0;
198 n
->vqs
[i
].ubufs
= NULL
;
199 n
->vqs
[i
].vhost_hlen
= 0;
200 n
->vqs
[i
].sock_hlen
= 0;
205 static void vhost_net_tx_packet(struct vhost_net
*net
)
208 if (net
->tx_packets
< 1024)
211 net
->tx_zcopy_err
= 0;
214 static void vhost_net_tx_err(struct vhost_net
*net
)
219 static bool vhost_net_tx_select_zcopy(struct vhost_net
*net
)
221 /* TX flush waits for outstanding DMAs to be done.
222 * Don't start new DMAs.
224 return !net
->tx_flush
&&
225 net
->tx_packets
/ 64 >= net
->tx_zcopy_err
;
228 static bool vhost_sock_zcopy(struct socket
*sock
)
230 return unlikely(experimental_zcopytx
) &&
231 sock_flag(sock
->sk
, SOCK_ZEROCOPY
);
234 /* In case of DMA done not in order in lower device driver for some reason.
235 * upend_idx is used to track end of used idx, done_idx is used to track head
236 * of used idx. Once lower device DMA done contiguously, we will signal KVM
239 static void vhost_zerocopy_signal_used(struct vhost_net
*net
,
240 struct vhost_virtqueue
*vq
)
242 struct vhost_net_virtqueue
*nvq
=
243 container_of(vq
, struct vhost_net_virtqueue
, vq
);
247 for (i
= nvq
->done_idx
; i
!= nvq
->upend_idx
; i
= (i
+ 1) % UIO_MAXIOV
) {
248 if (vq
->heads
[i
].len
== VHOST_DMA_FAILED_LEN
)
249 vhost_net_tx_err(net
);
250 if (VHOST_DMA_IS_DONE(vq
->heads
[i
].len
)) {
251 vq
->heads
[i
].len
= VHOST_DMA_CLEAR_LEN
;
257 add
= min(UIO_MAXIOV
- nvq
->done_idx
, j
);
258 vhost_add_used_and_signal_n(vq
->dev
, vq
,
259 &vq
->heads
[nvq
->done_idx
], add
);
260 nvq
->done_idx
= (nvq
->done_idx
+ add
) % UIO_MAXIOV
;
265 static void vhost_zerocopy_callback(struct ubuf_info
*ubuf
, bool success
)
267 struct vhost_net_ubuf_ref
*ubufs
= ubuf
->ctx
;
268 struct vhost_virtqueue
*vq
= ubufs
->vq
;
273 /* set len to mark this desc buffers done DMA */
274 vq
->heads
[ubuf
->desc
].len
= success
?
275 VHOST_DMA_DONE_LEN
: VHOST_DMA_FAILED_LEN
;
276 cnt
= vhost_net_ubuf_put(ubufs
);
279 * Trigger polling thread if guest stopped submitting new buffers:
280 * in this case, the refcount after decrement will eventually reach 1.
281 * We also trigger polling periodically after each 16 packets
282 * (the value 16 here is more or less arbitrary, it's tuned to trigger
283 * less than 10% of times).
285 if (cnt
<= 1 || !(cnt
% 16))
286 vhost_poll_queue(&vq
->poll
);
288 rcu_read_unlock_bh();
291 /* Expects to be always run from workqueue - which acts as
292 * read-size critical section for our kind of RCU. */
293 static void handle_tx(struct vhost_net
*net
)
295 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
296 struct vhost_virtqueue
*vq
= &nvq
->vq
;
299 struct msghdr msg
= {
304 .msg_flags
= MSG_DONTWAIT
,
306 size_t len
, total_len
= 0;
310 struct vhost_net_ubuf_ref
*uninitialized_var(ubufs
);
311 bool zcopy
, zcopy_used
;
313 mutex_lock(&vq
->mutex
);
314 sock
= vq
->private_data
;
318 vhost_disable_notify(&net
->dev
, vq
);
320 hdr_size
= nvq
->vhost_hlen
;
324 /* Release DMAs done buffers first */
326 vhost_zerocopy_signal_used(net
, vq
);
328 /* If more outstanding DMAs, queue the work.
329 * Handle upend_idx wrap around
331 if (unlikely((nvq
->upend_idx
+ vq
->num
- VHOST_MAX_PEND
)
332 % UIO_MAXIOV
== nvq
->done_idx
))
335 head
= vhost_get_vq_desc(vq
, vq
->iov
,
339 /* On error, stop handling until the next kick. */
340 if (unlikely(head
< 0))
342 /* Nothing new? Wait for eventfd to tell us they refilled. */
343 if (head
== vq
->num
) {
344 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
345 vhost_disable_notify(&net
->dev
, vq
);
351 vq_err(vq
, "Unexpected descriptor format for TX: "
352 "out %d, int %d\n", out
, in
);
355 /* Skip header. TODO: support TSO. */
356 len
= iov_length(vq
->iov
, out
);
357 iov_iter_init(&msg
.msg_iter
, WRITE
, vq
->iov
, out
, len
);
358 iov_iter_advance(&msg
.msg_iter
, hdr_size
);
360 if (!iov_iter_count(&msg
.msg_iter
)) {
361 vq_err(vq
, "Unexpected header len for TX: "
362 "%zd expected %zd\n",
366 len
= iov_iter_count(&msg
.msg_iter
);
368 zcopy_used
= zcopy
&& len
>= VHOST_GOODCOPY_LEN
369 && (nvq
->upend_idx
+ 1) % UIO_MAXIOV
!=
371 && vhost_net_tx_select_zcopy(net
);
373 /* use msg_control to pass vhost zerocopy ubuf info to skb */
375 struct ubuf_info
*ubuf
;
376 ubuf
= nvq
->ubuf_info
+ nvq
->upend_idx
;
378 vq
->heads
[nvq
->upend_idx
].id
= cpu_to_vhost32(vq
, head
);
379 vq
->heads
[nvq
->upend_idx
].len
= VHOST_DMA_IN_PROGRESS
;
380 ubuf
->callback
= vhost_zerocopy_callback
;
381 ubuf
->ctx
= nvq
->ubufs
;
382 ubuf
->desc
= nvq
->upend_idx
;
383 msg
.msg_control
= ubuf
;
384 msg
.msg_controllen
= sizeof(ubuf
);
386 atomic_inc(&ubufs
->refcount
);
387 nvq
->upend_idx
= (nvq
->upend_idx
+ 1) % UIO_MAXIOV
;
389 msg
.msg_control
= NULL
;
392 /* TODO: Check specific error and bomb out unless ENOBUFS? */
393 err
= sock
->ops
->sendmsg(sock
, &msg
, len
);
394 if (unlikely(err
< 0)) {
396 vhost_net_ubuf_put(ubufs
);
397 nvq
->upend_idx
= ((unsigned)nvq
->upend_idx
- 1)
400 vhost_discard_vq_desc(vq
, 1);
404 pr_debug("Truncated TX packet: "
405 " len %d != %zd\n", err
, len
);
407 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
409 vhost_zerocopy_signal_used(net
, vq
);
411 vhost_net_tx_packet(net
);
412 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
413 vhost_poll_queue(&vq
->poll
);
418 mutex_unlock(&vq
->mutex
);
421 static int peek_head_len(struct sock
*sk
)
423 struct sk_buff
*head
;
427 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
428 head
= skb_peek(&sk
->sk_receive_queue
);
431 if (skb_vlan_tag_present(head
))
435 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
439 /* This is a multi-buffer version of vhost_get_desc, that works if
440 * vq has read descriptors only.
441 * @vq - the relevant virtqueue
442 * @datalen - data length we'll be reading
443 * @iovcount - returned count of io vectors we fill
445 * @log_num - log offset
446 * @quota - headcount quota, 1 for big buffer
447 * returns number of buffer heads allocated, negative on error
449 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
450 struct vring_used_elem
*heads
,
453 struct vhost_log
*log
,
457 unsigned int out
, in
;
462 /* len is always initialized before use since we are always called with
465 u32
uninitialized_var(len
);
467 while (datalen
> 0 && headcount
< quota
) {
468 if (unlikely(seg
>= UIO_MAXIOV
)) {
472 r
= vhost_get_vq_desc(vq
, vq
->iov
+ seg
,
473 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
483 if (unlikely(out
|| in
<= 0)) {
484 vq_err(vq
, "unexpected descriptor format for RX: "
485 "out %d, in %d\n", out
, in
);
493 heads
[headcount
].id
= cpu_to_vhost32(vq
, d
);
494 len
= iov_length(vq
->iov
+ seg
, in
);
495 heads
[headcount
].len
= cpu_to_vhost32(vq
, len
);
500 heads
[headcount
- 1].len
= cpu_to_vhost32(vq
, len
+ datalen
);
506 if (unlikely(datalen
> 0)) {
512 vhost_discard_vq_desc(vq
, headcount
);
516 /* Expects to be always run from workqueue - which acts as
517 * read-size critical section for our kind of RCU. */
518 static void handle_rx(struct vhost_net
*net
)
520 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
521 struct vhost_virtqueue
*vq
= &nvq
->vq
;
522 unsigned uninitialized_var(in
), log
;
523 struct vhost_log
*vq_log
;
524 struct msghdr msg
= {
527 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
529 .msg_flags
= MSG_DONTWAIT
,
531 struct virtio_net_hdr hdr
= {
533 .gso_type
= VIRTIO_NET_HDR_GSO_NONE
535 size_t total_len
= 0;
538 size_t vhost_hlen
, sock_hlen
;
539 size_t vhost_len
, sock_len
;
541 struct iov_iter fixup
;
542 __virtio16 num_buffers
;
544 mutex_lock(&vq
->mutex
);
545 sock
= vq
->private_data
;
548 vhost_disable_notify(&net
->dev
, vq
);
550 vhost_hlen
= nvq
->vhost_hlen
;
551 sock_hlen
= nvq
->sock_hlen
;
553 vq_log
= unlikely(vhost_has_feature(vq
, VHOST_F_LOG_ALL
)) ?
555 mergeable
= vhost_has_feature(vq
, VIRTIO_NET_F_MRG_RXBUF
);
557 while ((sock_len
= peek_head_len(sock
->sk
))) {
558 sock_len
+= sock_hlen
;
559 vhost_len
= sock_len
+ vhost_hlen
;
560 headcount
= get_rx_bufs(vq
, vq
->heads
, vhost_len
,
562 likely(mergeable
) ? UIO_MAXIOV
: 1);
563 /* On error, stop handling until the next kick. */
564 if (unlikely(headcount
< 0))
566 /* On overrun, truncate and discard */
567 if (unlikely(headcount
> UIO_MAXIOV
)) {
568 iov_iter_init(&msg
.msg_iter
, READ
, vq
->iov
, 1, 1);
569 err
= sock
->ops
->recvmsg(sock
, &msg
,
570 1, MSG_DONTWAIT
| MSG_TRUNC
);
571 pr_debug("Discarded rx packet: len %zd\n", sock_len
);
574 /* OK, now we need to know about added descriptors. */
576 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
577 /* They have slipped one in as we were
578 * doing that: check again. */
579 vhost_disable_notify(&net
->dev
, vq
);
582 /* Nothing new? Wait for eventfd to tell us
586 /* We don't need to be notified again. */
587 iov_iter_init(&msg
.msg_iter
, READ
, vq
->iov
, in
, vhost_len
);
588 fixup
= msg
.msg_iter
;
589 if (unlikely((vhost_hlen
))) {
590 /* We will supply the header ourselves
593 iov_iter_advance(&msg
.msg_iter
, vhost_hlen
);
595 /* It'll come from socket; we'll need to patch
596 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF
598 iov_iter_advance(&fixup
, sizeof(hdr
));
600 err
= sock
->ops
->recvmsg(sock
, &msg
,
601 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
602 /* Userspace might have consumed the packet meanwhile:
603 * it's not supposed to do this usually, but might be hard
604 * to prevent. Discard data we got (if any) and keep going. */
605 if (unlikely(err
!= sock_len
)) {
606 pr_debug("Discarded rx packet: "
607 " len %d, expected %zd\n", err
, sock_len
);
608 vhost_discard_vq_desc(vq
, headcount
);
611 /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
612 if (unlikely(vhost_hlen
) &&
613 copy_to_iter(&hdr
, sizeof(hdr
), &fixup
) != sizeof(hdr
)) {
614 vq_err(vq
, "Unable to write vnet_hdr at addr %p\n",
618 /* TODO: Should check and handle checksum. */
620 num_buffers
= cpu_to_vhost16(vq
, headcount
);
621 if (likely(mergeable
) &&
622 copy_to_iter(&num_buffers
, 2, &fixup
) != 2) {
623 vq_err(vq
, "Failed num_buffers write");
624 vhost_discard_vq_desc(vq
, headcount
);
627 vhost_add_used_and_signal_n(&net
->dev
, vq
, vq
->heads
,
629 if (unlikely(vq_log
))
630 vhost_log_write(vq
, vq_log
, log
, vhost_len
);
631 total_len
+= vhost_len
;
632 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
633 vhost_poll_queue(&vq
->poll
);
638 mutex_unlock(&vq
->mutex
);
641 static void handle_tx_kick(struct vhost_work
*work
)
643 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
645 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
650 static void handle_rx_kick(struct vhost_work
*work
)
652 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
654 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
659 static void handle_tx_net(struct vhost_work
*work
)
661 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
662 poll
[VHOST_NET_VQ_TX
].work
);
666 static void handle_rx_net(struct vhost_work
*work
)
668 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
669 poll
[VHOST_NET_VQ_RX
].work
);
673 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
676 struct vhost_dev
*dev
;
677 struct vhost_virtqueue
**vqs
;
680 n
= kmalloc(sizeof *n
, GFP_KERNEL
| __GFP_NOWARN
| __GFP_REPEAT
);
682 n
= vmalloc(sizeof *n
);
686 vqs
= kmalloc(VHOST_NET_VQ_MAX
* sizeof(*vqs
), GFP_KERNEL
);
693 vqs
[VHOST_NET_VQ_TX
] = &n
->vqs
[VHOST_NET_VQ_TX
].vq
;
694 vqs
[VHOST_NET_VQ_RX
] = &n
->vqs
[VHOST_NET_VQ_RX
].vq
;
695 n
->vqs
[VHOST_NET_VQ_TX
].vq
.handle_kick
= handle_tx_kick
;
696 n
->vqs
[VHOST_NET_VQ_RX
].vq
.handle_kick
= handle_rx_kick
;
697 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
698 n
->vqs
[i
].ubufs
= NULL
;
699 n
->vqs
[i
].ubuf_info
= NULL
;
700 n
->vqs
[i
].upend_idx
= 0;
701 n
->vqs
[i
].done_idx
= 0;
702 n
->vqs
[i
].vhost_hlen
= 0;
703 n
->vqs
[i
].sock_hlen
= 0;
705 vhost_dev_init(dev
, vqs
, VHOST_NET_VQ_MAX
);
707 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, POLLOUT
, dev
);
708 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, POLLIN
, dev
);
715 static void vhost_net_disable_vq(struct vhost_net
*n
,
716 struct vhost_virtqueue
*vq
)
718 struct vhost_net_virtqueue
*nvq
=
719 container_of(vq
, struct vhost_net_virtqueue
, vq
);
720 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
721 if (!vq
->private_data
)
723 vhost_poll_stop(poll
);
726 static int vhost_net_enable_vq(struct vhost_net
*n
,
727 struct vhost_virtqueue
*vq
)
729 struct vhost_net_virtqueue
*nvq
=
730 container_of(vq
, struct vhost_net_virtqueue
, vq
);
731 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
734 sock
= vq
->private_data
;
738 return vhost_poll_start(poll
, sock
->file
);
741 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
742 struct vhost_virtqueue
*vq
)
746 mutex_lock(&vq
->mutex
);
747 sock
= vq
->private_data
;
748 vhost_net_disable_vq(n
, vq
);
749 vq
->private_data
= NULL
;
750 mutex_unlock(&vq
->mutex
);
754 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
755 struct socket
**rx_sock
)
757 *tx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_TX
].vq
);
758 *rx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_RX
].vq
);
761 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
763 vhost_poll_flush(n
->poll
+ index
);
764 vhost_poll_flush(&n
->vqs
[index
].vq
.poll
);
767 static void vhost_net_flush(struct vhost_net
*n
)
769 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
770 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
771 if (n
->vqs
[VHOST_NET_VQ_TX
].ubufs
) {
772 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
774 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
775 /* Wait for all lower device DMAs done. */
776 vhost_net_ubuf_put_and_wait(n
->vqs
[VHOST_NET_VQ_TX
].ubufs
);
777 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
779 atomic_set(&n
->vqs
[VHOST_NET_VQ_TX
].ubufs
->refcount
, 1);
780 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
784 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
786 struct vhost_net
*n
= f
->private_data
;
787 struct socket
*tx_sock
;
788 struct socket
*rx_sock
;
790 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
792 vhost_dev_stop(&n
->dev
);
793 vhost_dev_cleanup(&n
->dev
, false);
794 vhost_net_vq_reset(n
);
799 /* Make sure no callbacks are outstanding */
800 synchronize_rcu_bh();
801 /* We do an extra flush before freeing memory,
802 * since jobs can re-queue themselves. */
809 static struct socket
*get_raw_socket(int fd
)
812 struct sockaddr_ll sa
;
813 char buf
[MAX_ADDR_LEN
];
815 int uaddr_len
= sizeof uaddr
, r
;
816 struct socket
*sock
= sockfd_lookup(fd
, &r
);
819 return ERR_PTR(-ENOTSOCK
);
821 /* Parameter checking */
822 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
823 r
= -ESOCKTNOSUPPORT
;
827 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
,
832 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
842 static struct socket
*get_tap_socket(int fd
)
844 struct file
*file
= fget(fd
);
848 return ERR_PTR(-EBADF
);
849 sock
= tun_get_socket(file
);
852 sock
= macvtap_get_socket(file
);
858 static struct socket
*get_socket(int fd
)
862 /* special case to disable backend */
865 sock
= get_raw_socket(fd
);
868 sock
= get_tap_socket(fd
);
871 return ERR_PTR(-ENOTSOCK
);
874 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
876 struct socket
*sock
, *oldsock
;
877 struct vhost_virtqueue
*vq
;
878 struct vhost_net_virtqueue
*nvq
;
879 struct vhost_net_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
882 mutex_lock(&n
->dev
.mutex
);
883 r
= vhost_dev_check_owner(&n
->dev
);
887 if (index
>= VHOST_NET_VQ_MAX
) {
891 vq
= &n
->vqs
[index
].vq
;
892 nvq
= &n
->vqs
[index
];
893 mutex_lock(&vq
->mutex
);
895 /* Verify that ring has been setup correctly. */
896 if (!vhost_vq_access_ok(vq
)) {
900 sock
= get_socket(fd
);
906 /* start polling new socket */
907 oldsock
= vq
->private_data
;
908 if (sock
!= oldsock
) {
909 ubufs
= vhost_net_ubuf_alloc(vq
,
910 sock
&& vhost_sock_zcopy(sock
));
916 vhost_net_disable_vq(n
, vq
);
917 vq
->private_data
= sock
;
918 r
= vhost_init_used(vq
);
921 r
= vhost_net_enable_vq(n
, vq
);
925 oldubufs
= nvq
->ubufs
;
933 mutex_unlock(&vq
->mutex
);
936 vhost_net_ubuf_put_wait_and_free(oldubufs
);
937 mutex_lock(&vq
->mutex
);
938 vhost_zerocopy_signal_used(n
, vq
);
939 mutex_unlock(&vq
->mutex
);
943 vhost_net_flush_vq(n
, index
);
947 mutex_unlock(&n
->dev
.mutex
);
951 vq
->private_data
= oldsock
;
952 vhost_net_enable_vq(n
, vq
);
954 vhost_net_ubuf_put_wait_and_free(ubufs
);
958 mutex_unlock(&vq
->mutex
);
960 mutex_unlock(&n
->dev
.mutex
);
964 static long vhost_net_reset_owner(struct vhost_net
*n
)
966 struct socket
*tx_sock
= NULL
;
967 struct socket
*rx_sock
= NULL
;
969 struct vhost_memory
*memory
;
971 mutex_lock(&n
->dev
.mutex
);
972 err
= vhost_dev_check_owner(&n
->dev
);
975 memory
= vhost_dev_reset_owner_prepare();
980 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
982 vhost_dev_reset_owner(&n
->dev
, memory
);
983 vhost_net_vq_reset(n
);
985 mutex_unlock(&n
->dev
.mutex
);
993 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
995 size_t vhost_hlen
, sock_hlen
, hdr_len
;
998 hdr_len
= (features
& ((1ULL << VIRTIO_NET_F_MRG_RXBUF
) |
999 (1ULL << VIRTIO_F_VERSION_1
))) ?
1000 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
1001 sizeof(struct virtio_net_hdr
);
1002 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
1003 /* vhost provides vnet_hdr */
1004 vhost_hlen
= hdr_len
;
1007 /* socket provides vnet_hdr */
1009 sock_hlen
= hdr_len
;
1011 mutex_lock(&n
->dev
.mutex
);
1012 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
1013 !vhost_log_access_ok(&n
->dev
)) {
1014 mutex_unlock(&n
->dev
.mutex
);
1017 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
1018 mutex_lock(&n
->vqs
[i
].vq
.mutex
);
1019 n
->vqs
[i
].vq
.acked_features
= features
;
1020 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
1021 n
->vqs
[i
].sock_hlen
= sock_hlen
;
1022 mutex_unlock(&n
->vqs
[i
].vq
.mutex
);
1024 mutex_unlock(&n
->dev
.mutex
);
1028 static long vhost_net_set_owner(struct vhost_net
*n
)
1032 mutex_lock(&n
->dev
.mutex
);
1033 if (vhost_dev_has_owner(&n
->dev
)) {
1037 r
= vhost_net_set_ubuf_info(n
);
1040 r
= vhost_dev_set_owner(&n
->dev
);
1042 vhost_net_clear_ubuf_info(n
);
1045 mutex_unlock(&n
->dev
.mutex
);
1049 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
1052 struct vhost_net
*n
= f
->private_data
;
1053 void __user
*argp
= (void __user
*)arg
;
1054 u64 __user
*featurep
= argp
;
1055 struct vhost_vring_file backend
;
1060 case VHOST_NET_SET_BACKEND
:
1061 if (copy_from_user(&backend
, argp
, sizeof backend
))
1063 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
1064 case VHOST_GET_FEATURES
:
1065 features
= VHOST_NET_FEATURES
;
1066 if (copy_to_user(featurep
, &features
, sizeof features
))
1069 case VHOST_SET_FEATURES
:
1070 if (copy_from_user(&features
, featurep
, sizeof features
))
1072 if (features
& ~VHOST_NET_FEATURES
)
1074 return vhost_net_set_features(n
, features
);
1075 case VHOST_RESET_OWNER
:
1076 return vhost_net_reset_owner(n
);
1077 case VHOST_SET_OWNER
:
1078 return vhost_net_set_owner(n
);
1080 mutex_lock(&n
->dev
.mutex
);
1081 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, argp
);
1082 if (r
== -ENOIOCTLCMD
)
1083 r
= vhost_vring_ioctl(&n
->dev
, ioctl
, argp
);
1086 mutex_unlock(&n
->dev
.mutex
);
1091 #ifdef CONFIG_COMPAT
1092 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
1095 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
1099 static const struct file_operations vhost_net_fops
= {
1100 .owner
= THIS_MODULE
,
1101 .release
= vhost_net_release
,
1102 .unlocked_ioctl
= vhost_net_ioctl
,
1103 #ifdef CONFIG_COMPAT
1104 .compat_ioctl
= vhost_net_compat_ioctl
,
1106 .open
= vhost_net_open
,
1107 .llseek
= noop_llseek
,
1110 static struct miscdevice vhost_net_misc
= {
1111 .minor
= VHOST_NET_MINOR
,
1112 .name
= "vhost-net",
1113 .fops
= &vhost_net_fops
,
1116 static int vhost_net_init(void)
1118 if (experimental_zcopytx
)
1119 vhost_net_enable_zcopy(VHOST_NET_VQ_TX
);
1120 return misc_register(&vhost_net_misc
);
1122 module_init(vhost_net_init
);
1124 static void vhost_net_exit(void)
1126 misc_deregister(&vhost_net_misc
);
1128 module_exit(vhost_net_exit
);
1130 MODULE_VERSION("0.0.1");
1131 MODULE_LICENSE("GPL v2");
1132 MODULE_AUTHOR("Michael S. Tsirkin");
1133 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1134 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
1135 MODULE_ALIAS("devname:vhost-net");