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
)
73 struct vhost_net_ubuf_ref
{
74 /* refcount follows semantics similar to kref:
75 * 0: object is released
76 * 1: no outstanding ubufs
77 * >1: outstanding ubufs
80 wait_queue_head_t wait
;
81 struct vhost_virtqueue
*vq
;
84 struct vhost_net_virtqueue
{
85 struct vhost_virtqueue vq
;
88 /* vhost zerocopy support fields below: */
89 /* last used idx for outstanding DMA zerocopy buffers */
91 /* first used idx for DMA done zerocopy buffers */
93 /* an array of userspace buffers info */
94 struct ubuf_info
*ubuf_info
;
95 /* Reference counting for outstanding ubufs.
96 * Protected by vq mutex. Writers must also take device mutex. */
97 struct vhost_net_ubuf_ref
*ubufs
;
101 struct vhost_dev dev
;
102 struct vhost_net_virtqueue vqs
[VHOST_NET_VQ_MAX
];
103 struct vhost_poll poll
[VHOST_NET_VQ_MAX
];
104 /* Number of TX recently submitted.
105 * Protected by tx vq lock. */
107 /* Number of times zerocopy TX recently failed.
108 * Protected by tx vq lock. */
109 unsigned tx_zcopy_err
;
110 /* Flush in progress. Protected by tx vq lock. */
114 static unsigned vhost_net_zcopy_mask __read_mostly
;
116 static void vhost_net_enable_zcopy(int vq
)
118 vhost_net_zcopy_mask
|= 0x1 << vq
;
121 static struct vhost_net_ubuf_ref
*
122 vhost_net_ubuf_alloc(struct vhost_virtqueue
*vq
, bool zcopy
)
124 struct vhost_net_ubuf_ref
*ubufs
;
125 /* No zero copy backend? Nothing to count. */
128 ubufs
= kmalloc(sizeof(*ubufs
), GFP_KERNEL
);
130 return ERR_PTR(-ENOMEM
);
131 atomic_set(&ubufs
->refcount
, 1);
132 init_waitqueue_head(&ubufs
->wait
);
137 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref
*ubufs
)
139 int r
= atomic_sub_return(1, &ubufs
->refcount
);
141 wake_up(&ubufs
->wait
);
145 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref
*ubufs
)
147 vhost_net_ubuf_put(ubufs
);
148 wait_event(ubufs
->wait
, !atomic_read(&ubufs
->refcount
));
151 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref
*ubufs
)
153 vhost_net_ubuf_put_and_wait(ubufs
);
157 static void vhost_net_clear_ubuf_info(struct vhost_net
*n
)
161 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
162 kfree(n
->vqs
[i
].ubuf_info
);
163 n
->vqs
[i
].ubuf_info
= NULL
;
167 static int vhost_net_set_ubuf_info(struct vhost_net
*n
)
172 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
173 zcopy
= vhost_net_zcopy_mask
& (0x1 << i
);
176 n
->vqs
[i
].ubuf_info
= kmalloc(sizeof(*n
->vqs
[i
].ubuf_info
) *
177 UIO_MAXIOV
, GFP_KERNEL
);
178 if (!n
->vqs
[i
].ubuf_info
)
184 vhost_net_clear_ubuf_info(n
);
188 static void vhost_net_vq_reset(struct vhost_net
*n
)
192 vhost_net_clear_ubuf_info(n
);
194 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
195 n
->vqs
[i
].done_idx
= 0;
196 n
->vqs
[i
].upend_idx
= 0;
197 n
->vqs
[i
].ubufs
= NULL
;
198 n
->vqs
[i
].vhost_hlen
= 0;
199 n
->vqs
[i
].sock_hlen
= 0;
204 static void vhost_net_tx_packet(struct vhost_net
*net
)
207 if (net
->tx_packets
< 1024)
210 net
->tx_zcopy_err
= 0;
213 static void vhost_net_tx_err(struct vhost_net
*net
)
218 static bool vhost_net_tx_select_zcopy(struct vhost_net
*net
)
220 /* TX flush waits for outstanding DMAs to be done.
221 * Don't start new DMAs.
223 return !net
->tx_flush
&&
224 net
->tx_packets
/ 64 >= net
->tx_zcopy_err
;
227 static bool vhost_sock_zcopy(struct socket
*sock
)
229 return unlikely(experimental_zcopytx
) &&
230 sock_flag(sock
->sk
, SOCK_ZEROCOPY
);
233 /* In case of DMA done not in order in lower device driver for some reason.
234 * upend_idx is used to track end of used idx, done_idx is used to track head
235 * of used idx. Once lower device DMA done contiguously, we will signal KVM
238 static void vhost_zerocopy_signal_used(struct vhost_net
*net
,
239 struct vhost_virtqueue
*vq
)
241 struct vhost_net_virtqueue
*nvq
=
242 container_of(vq
, struct vhost_net_virtqueue
, vq
);
246 for (i
= nvq
->done_idx
; i
!= nvq
->upend_idx
; i
= (i
+ 1) % UIO_MAXIOV
) {
247 if (vq
->heads
[i
].len
== VHOST_DMA_FAILED_LEN
)
248 vhost_net_tx_err(net
);
249 if (VHOST_DMA_IS_DONE(vq
->heads
[i
].len
)) {
250 vq
->heads
[i
].len
= VHOST_DMA_CLEAR_LEN
;
256 add
= min(UIO_MAXIOV
- nvq
->done_idx
, j
);
257 vhost_add_used_and_signal_n(vq
->dev
, vq
,
258 &vq
->heads
[nvq
->done_idx
], add
);
259 nvq
->done_idx
= (nvq
->done_idx
+ add
) % UIO_MAXIOV
;
264 static void vhost_zerocopy_callback(struct ubuf_info
*ubuf
, bool success
)
266 struct vhost_net_ubuf_ref
*ubufs
= ubuf
->ctx
;
267 struct vhost_virtqueue
*vq
= ubufs
->vq
;
272 /* set len to mark this desc buffers done DMA */
273 vq
->heads
[ubuf
->desc
].len
= success
?
274 VHOST_DMA_DONE_LEN
: VHOST_DMA_FAILED_LEN
;
275 cnt
= vhost_net_ubuf_put(ubufs
);
278 * Trigger polling thread if guest stopped submitting new buffers:
279 * in this case, the refcount after decrement will eventually reach 1.
280 * We also trigger polling periodically after each 16 packets
281 * (the value 16 here is more or less arbitrary, it's tuned to trigger
282 * less than 10% of times).
284 if (cnt
<= 1 || !(cnt
% 16))
285 vhost_poll_queue(&vq
->poll
);
287 rcu_read_unlock_bh();
290 static inline unsigned long busy_clock(void)
292 return local_clock() >> 10;
295 static bool vhost_can_busy_poll(struct vhost_dev
*dev
,
296 unsigned long endtime
)
298 return likely(!need_resched()) &&
299 likely(!time_after(busy_clock(), endtime
)) &&
300 likely(!signal_pending(current
)) &&
301 !vhost_has_work(dev
);
304 static void vhost_net_disable_vq(struct vhost_net
*n
,
305 struct vhost_virtqueue
*vq
)
307 struct vhost_net_virtqueue
*nvq
=
308 container_of(vq
, struct vhost_net_virtqueue
, vq
);
309 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
310 if (!vq
->private_data
)
312 vhost_poll_stop(poll
);
315 static int vhost_net_enable_vq(struct vhost_net
*n
,
316 struct vhost_virtqueue
*vq
)
318 struct vhost_net_virtqueue
*nvq
=
319 container_of(vq
, struct vhost_net_virtqueue
, vq
);
320 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
323 sock
= vq
->private_data
;
327 return vhost_poll_start(poll
, sock
->file
);
330 static int vhost_net_tx_get_vq_desc(struct vhost_net
*net
,
331 struct vhost_virtqueue
*vq
,
332 struct iovec iov
[], unsigned int iov_size
,
333 unsigned int *out_num
, unsigned int *in_num
)
335 unsigned long uninitialized_var(endtime
);
336 int r
= vhost_get_vq_desc(vq
, vq
->iov
, ARRAY_SIZE(vq
->iov
),
337 out_num
, in_num
, NULL
, NULL
);
339 if (r
== vq
->num
&& vq
->busyloop_timeout
) {
341 endtime
= busy_clock() + vq
->busyloop_timeout
;
342 while (vhost_can_busy_poll(vq
->dev
, endtime
) &&
343 vhost_vq_avail_empty(vq
->dev
, vq
))
344 cpu_relax_lowlatency();
346 r
= vhost_get_vq_desc(vq
, vq
->iov
, ARRAY_SIZE(vq
->iov
),
347 out_num
, in_num
, NULL
, NULL
);
353 /* Expects to be always run from workqueue - which acts as
354 * read-size critical section for our kind of RCU. */
355 static void handle_tx(struct vhost_net
*net
)
357 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
358 struct vhost_virtqueue
*vq
= &nvq
->vq
;
361 struct msghdr msg
= {
366 .msg_flags
= MSG_DONTWAIT
,
368 size_t len
, total_len
= 0;
372 struct vhost_net_ubuf_ref
*uninitialized_var(ubufs
);
373 bool zcopy
, zcopy_used
;
375 mutex_lock(&vq
->mutex
);
376 sock
= vq
->private_data
;
380 vhost_disable_notify(&net
->dev
, vq
);
382 hdr_size
= nvq
->vhost_hlen
;
386 /* Release DMAs done buffers first */
388 vhost_zerocopy_signal_used(net
, vq
);
390 /* If more outstanding DMAs, queue the work.
391 * Handle upend_idx wrap around
393 if (unlikely((nvq
->upend_idx
+ vq
->num
- VHOST_MAX_PEND
)
394 % UIO_MAXIOV
== nvq
->done_idx
))
397 head
= vhost_net_tx_get_vq_desc(net
, vq
, vq
->iov
,
400 /* On error, stop handling until the next kick. */
401 if (unlikely(head
< 0))
403 /* Nothing new? Wait for eventfd to tell us they refilled. */
404 if (head
== vq
->num
) {
405 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
406 vhost_disable_notify(&net
->dev
, vq
);
412 vq_err(vq
, "Unexpected descriptor format for TX: "
413 "out %d, int %d\n", out
, in
);
416 /* Skip header. TODO: support TSO. */
417 len
= iov_length(vq
->iov
, out
);
418 iov_iter_init(&msg
.msg_iter
, WRITE
, vq
->iov
, out
, len
);
419 iov_iter_advance(&msg
.msg_iter
, hdr_size
);
421 if (!msg_data_left(&msg
)) {
422 vq_err(vq
, "Unexpected header len for TX: "
423 "%zd expected %zd\n",
427 len
= msg_data_left(&msg
);
429 zcopy_used
= zcopy
&& len
>= VHOST_GOODCOPY_LEN
430 && (nvq
->upend_idx
+ 1) % UIO_MAXIOV
!=
432 && vhost_net_tx_select_zcopy(net
);
434 /* use msg_control to pass vhost zerocopy ubuf info to skb */
436 struct ubuf_info
*ubuf
;
437 ubuf
= nvq
->ubuf_info
+ nvq
->upend_idx
;
439 vq
->heads
[nvq
->upend_idx
].id
= cpu_to_vhost32(vq
, head
);
440 vq
->heads
[nvq
->upend_idx
].len
= VHOST_DMA_IN_PROGRESS
;
441 ubuf
->callback
= vhost_zerocopy_callback
;
442 ubuf
->ctx
= nvq
->ubufs
;
443 ubuf
->desc
= nvq
->upend_idx
;
444 msg
.msg_control
= ubuf
;
445 msg
.msg_controllen
= sizeof(ubuf
);
447 atomic_inc(&ubufs
->refcount
);
448 nvq
->upend_idx
= (nvq
->upend_idx
+ 1) % UIO_MAXIOV
;
450 msg
.msg_control
= NULL
;
453 /* TODO: Check specific error and bomb out unless ENOBUFS? */
454 err
= sock
->ops
->sendmsg(sock
, &msg
, len
);
455 if (unlikely(err
< 0)) {
457 vhost_net_ubuf_put(ubufs
);
458 nvq
->upend_idx
= ((unsigned)nvq
->upend_idx
- 1)
461 vhost_discard_vq_desc(vq
, 1);
465 pr_debug("Truncated TX packet: "
466 " len %d != %zd\n", err
, len
);
468 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
470 vhost_zerocopy_signal_used(net
, vq
);
472 vhost_net_tx_packet(net
);
473 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
474 vhost_poll_queue(&vq
->poll
);
479 mutex_unlock(&vq
->mutex
);
482 static int peek_head_len(struct sock
*sk
)
484 struct sk_buff
*head
;
488 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
489 head
= skb_peek(&sk
->sk_receive_queue
);
492 if (skb_vlan_tag_present(head
))
496 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
500 static int vhost_net_rx_peek_head_len(struct vhost_net
*net
, struct sock
*sk
)
502 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
503 struct vhost_virtqueue
*vq
= &nvq
->vq
;
504 unsigned long uninitialized_var(endtime
);
505 int len
= peek_head_len(sk
);
507 if (!len
&& vq
->busyloop_timeout
) {
508 /* Both tx vq and rx socket were polled here */
509 mutex_lock(&vq
->mutex
);
510 vhost_disable_notify(&net
->dev
, vq
);
513 endtime
= busy_clock() + vq
->busyloop_timeout
;
515 while (vhost_can_busy_poll(&net
->dev
, endtime
) &&
516 skb_queue_empty(&sk
->sk_receive_queue
) &&
517 vhost_vq_avail_empty(&net
->dev
, vq
))
518 cpu_relax_lowlatency();
522 if (vhost_enable_notify(&net
->dev
, vq
))
523 vhost_poll_queue(&vq
->poll
);
524 mutex_unlock(&vq
->mutex
);
526 len
= peek_head_len(sk
);
532 /* This is a multi-buffer version of vhost_get_desc, that works if
533 * vq has read descriptors only.
534 * @vq - the relevant virtqueue
535 * @datalen - data length we'll be reading
536 * @iovcount - returned count of io vectors we fill
538 * @log_num - log offset
539 * @quota - headcount quota, 1 for big buffer
540 * returns number of buffer heads allocated, negative on error
542 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
543 struct vring_used_elem
*heads
,
546 struct vhost_log
*log
,
550 unsigned int out
, in
;
555 /* len is always initialized before use since we are always called with
558 u32
uninitialized_var(len
);
560 while (datalen
> 0 && headcount
< quota
) {
561 if (unlikely(seg
>= UIO_MAXIOV
)) {
565 r
= vhost_get_vq_desc(vq
, vq
->iov
+ seg
,
566 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
576 if (unlikely(out
|| in
<= 0)) {
577 vq_err(vq
, "unexpected descriptor format for RX: "
578 "out %d, in %d\n", out
, in
);
586 heads
[headcount
].id
= cpu_to_vhost32(vq
, d
);
587 len
= iov_length(vq
->iov
+ seg
, in
);
588 heads
[headcount
].len
= cpu_to_vhost32(vq
, len
);
593 heads
[headcount
- 1].len
= cpu_to_vhost32(vq
, len
+ datalen
);
599 if (unlikely(datalen
> 0)) {
605 vhost_discard_vq_desc(vq
, headcount
);
609 /* Expects to be always run from workqueue - which acts as
610 * read-size critical section for our kind of RCU. */
611 static void handle_rx(struct vhost_net
*net
)
613 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
614 struct vhost_virtqueue
*vq
= &nvq
->vq
;
615 unsigned uninitialized_var(in
), log
;
616 struct vhost_log
*vq_log
;
617 struct msghdr msg
= {
620 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
622 .msg_flags
= MSG_DONTWAIT
,
624 struct virtio_net_hdr hdr
= {
626 .gso_type
= VIRTIO_NET_HDR_GSO_NONE
628 size_t total_len
= 0;
631 size_t vhost_hlen
, sock_hlen
;
632 size_t vhost_len
, sock_len
;
634 struct iov_iter fixup
;
635 __virtio16 num_buffers
;
637 mutex_lock(&vq
->mutex
);
638 sock
= vq
->private_data
;
641 vhost_disable_notify(&net
->dev
, vq
);
642 vhost_net_disable_vq(net
, vq
);
644 vhost_hlen
= nvq
->vhost_hlen
;
645 sock_hlen
= nvq
->sock_hlen
;
647 vq_log
= unlikely(vhost_has_feature(vq
, VHOST_F_LOG_ALL
)) ?
649 mergeable
= vhost_has_feature(vq
, VIRTIO_NET_F_MRG_RXBUF
);
651 while ((sock_len
= vhost_net_rx_peek_head_len(net
, sock
->sk
))) {
652 sock_len
+= sock_hlen
;
653 vhost_len
= sock_len
+ vhost_hlen
;
654 headcount
= get_rx_bufs(vq
, vq
->heads
, vhost_len
,
656 likely(mergeable
) ? UIO_MAXIOV
: 1);
657 /* On error, stop handling until the next kick. */
658 if (unlikely(headcount
< 0))
660 /* On overrun, truncate and discard */
661 if (unlikely(headcount
> UIO_MAXIOV
)) {
662 iov_iter_init(&msg
.msg_iter
, READ
, vq
->iov
, 1, 1);
663 err
= sock
->ops
->recvmsg(sock
, &msg
,
664 1, MSG_DONTWAIT
| MSG_TRUNC
);
665 pr_debug("Discarded rx packet: len %zd\n", sock_len
);
668 /* OK, now we need to know about added descriptors. */
670 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
671 /* They have slipped one in as we were
672 * doing that: check again. */
673 vhost_disable_notify(&net
->dev
, vq
);
676 /* Nothing new? Wait for eventfd to tell us
680 /* We don't need to be notified again. */
681 iov_iter_init(&msg
.msg_iter
, READ
, vq
->iov
, in
, vhost_len
);
682 fixup
= msg
.msg_iter
;
683 if (unlikely((vhost_hlen
))) {
684 /* We will supply the header ourselves
687 iov_iter_advance(&msg
.msg_iter
, vhost_hlen
);
689 err
= sock
->ops
->recvmsg(sock
, &msg
,
690 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
691 /* Userspace might have consumed the packet meanwhile:
692 * it's not supposed to do this usually, but might be hard
693 * to prevent. Discard data we got (if any) and keep going. */
694 if (unlikely(err
!= sock_len
)) {
695 pr_debug("Discarded rx packet: "
696 " len %d, expected %zd\n", err
, sock_len
);
697 vhost_discard_vq_desc(vq
, headcount
);
700 /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
701 if (unlikely(vhost_hlen
)) {
702 if (copy_to_iter(&hdr
, sizeof(hdr
),
703 &fixup
) != sizeof(hdr
)) {
704 vq_err(vq
, "Unable to write vnet_hdr "
705 "at addr %p\n", vq
->iov
->iov_base
);
709 /* Header came from socket; we'll need to patch
710 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF
712 iov_iter_advance(&fixup
, sizeof(hdr
));
714 /* TODO: Should check and handle checksum. */
716 num_buffers
= cpu_to_vhost16(vq
, headcount
);
717 if (likely(mergeable
) &&
718 copy_to_iter(&num_buffers
, sizeof num_buffers
,
719 &fixup
) != sizeof num_buffers
) {
720 vq_err(vq
, "Failed num_buffers write");
721 vhost_discard_vq_desc(vq
, headcount
);
724 vhost_add_used_and_signal_n(&net
->dev
, vq
, vq
->heads
,
726 if (unlikely(vq_log
))
727 vhost_log_write(vq
, vq_log
, log
, vhost_len
);
728 total_len
+= vhost_len
;
729 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
730 vhost_poll_queue(&vq
->poll
);
734 vhost_net_enable_vq(net
, vq
);
736 mutex_unlock(&vq
->mutex
);
739 static void handle_tx_kick(struct vhost_work
*work
)
741 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
743 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
748 static void handle_rx_kick(struct vhost_work
*work
)
750 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
752 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
757 static void handle_tx_net(struct vhost_work
*work
)
759 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
760 poll
[VHOST_NET_VQ_TX
].work
);
764 static void handle_rx_net(struct vhost_work
*work
)
766 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
767 poll
[VHOST_NET_VQ_RX
].work
);
771 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
774 struct vhost_dev
*dev
;
775 struct vhost_virtqueue
**vqs
;
778 n
= kmalloc(sizeof *n
, GFP_KERNEL
| __GFP_NOWARN
| __GFP_REPEAT
);
780 n
= vmalloc(sizeof *n
);
784 vqs
= kmalloc(VHOST_NET_VQ_MAX
* sizeof(*vqs
), GFP_KERNEL
);
791 vqs
[VHOST_NET_VQ_TX
] = &n
->vqs
[VHOST_NET_VQ_TX
].vq
;
792 vqs
[VHOST_NET_VQ_RX
] = &n
->vqs
[VHOST_NET_VQ_RX
].vq
;
793 n
->vqs
[VHOST_NET_VQ_TX
].vq
.handle_kick
= handle_tx_kick
;
794 n
->vqs
[VHOST_NET_VQ_RX
].vq
.handle_kick
= handle_rx_kick
;
795 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
796 n
->vqs
[i
].ubufs
= NULL
;
797 n
->vqs
[i
].ubuf_info
= NULL
;
798 n
->vqs
[i
].upend_idx
= 0;
799 n
->vqs
[i
].done_idx
= 0;
800 n
->vqs
[i
].vhost_hlen
= 0;
801 n
->vqs
[i
].sock_hlen
= 0;
803 vhost_dev_init(dev
, vqs
, VHOST_NET_VQ_MAX
);
805 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, POLLOUT
, dev
);
806 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, POLLIN
, dev
);
813 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
814 struct vhost_virtqueue
*vq
)
818 mutex_lock(&vq
->mutex
);
819 sock
= vq
->private_data
;
820 vhost_net_disable_vq(n
, vq
);
821 vq
->private_data
= NULL
;
822 mutex_unlock(&vq
->mutex
);
826 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
827 struct socket
**rx_sock
)
829 *tx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_TX
].vq
);
830 *rx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_RX
].vq
);
833 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
835 vhost_poll_flush(n
->poll
+ index
);
836 vhost_poll_flush(&n
->vqs
[index
].vq
.poll
);
839 static void vhost_net_flush(struct vhost_net
*n
)
841 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
842 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
843 if (n
->vqs
[VHOST_NET_VQ_TX
].ubufs
) {
844 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
846 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
847 /* Wait for all lower device DMAs done. */
848 vhost_net_ubuf_put_and_wait(n
->vqs
[VHOST_NET_VQ_TX
].ubufs
);
849 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
851 atomic_set(&n
->vqs
[VHOST_NET_VQ_TX
].ubufs
->refcount
, 1);
852 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
856 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
858 struct vhost_net
*n
= f
->private_data
;
859 struct socket
*tx_sock
;
860 struct socket
*rx_sock
;
862 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
864 vhost_dev_stop(&n
->dev
);
865 vhost_dev_cleanup(&n
->dev
, false);
866 vhost_net_vq_reset(n
);
871 /* Make sure no callbacks are outstanding */
872 synchronize_rcu_bh();
873 /* We do an extra flush before freeing memory,
874 * since jobs can re-queue themselves. */
881 static struct socket
*get_raw_socket(int fd
)
884 struct sockaddr_ll sa
;
885 char buf
[MAX_ADDR_LEN
];
887 int uaddr_len
= sizeof uaddr
, r
;
888 struct socket
*sock
= sockfd_lookup(fd
, &r
);
891 return ERR_PTR(-ENOTSOCK
);
893 /* Parameter checking */
894 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
895 r
= -ESOCKTNOSUPPORT
;
899 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
,
904 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
914 static struct socket
*get_tap_socket(int fd
)
916 struct file
*file
= fget(fd
);
920 return ERR_PTR(-EBADF
);
921 sock
= tun_get_socket(file
);
924 sock
= macvtap_get_socket(file
);
930 static struct socket
*get_socket(int fd
)
934 /* special case to disable backend */
937 sock
= get_raw_socket(fd
);
940 sock
= get_tap_socket(fd
);
943 return ERR_PTR(-ENOTSOCK
);
946 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
948 struct socket
*sock
, *oldsock
;
949 struct vhost_virtqueue
*vq
;
950 struct vhost_net_virtqueue
*nvq
;
951 struct vhost_net_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
954 mutex_lock(&n
->dev
.mutex
);
955 r
= vhost_dev_check_owner(&n
->dev
);
959 if (index
>= VHOST_NET_VQ_MAX
) {
963 vq
= &n
->vqs
[index
].vq
;
964 nvq
= &n
->vqs
[index
];
965 mutex_lock(&vq
->mutex
);
967 /* Verify that ring has been setup correctly. */
968 if (!vhost_vq_access_ok(vq
)) {
972 sock
= get_socket(fd
);
978 /* start polling new socket */
979 oldsock
= vq
->private_data
;
980 if (sock
!= oldsock
) {
981 ubufs
= vhost_net_ubuf_alloc(vq
,
982 sock
&& vhost_sock_zcopy(sock
));
988 vhost_net_disable_vq(n
, vq
);
989 vq
->private_data
= sock
;
990 r
= vhost_vq_init_access(vq
);
993 r
= vhost_net_enable_vq(n
, vq
);
997 oldubufs
= nvq
->ubufs
;
1001 n
->tx_zcopy_err
= 0;
1002 n
->tx_flush
= false;
1005 mutex_unlock(&vq
->mutex
);
1008 vhost_net_ubuf_put_wait_and_free(oldubufs
);
1009 mutex_lock(&vq
->mutex
);
1010 vhost_zerocopy_signal_used(n
, vq
);
1011 mutex_unlock(&vq
->mutex
);
1015 vhost_net_flush_vq(n
, index
);
1016 sockfd_put(oldsock
);
1019 mutex_unlock(&n
->dev
.mutex
);
1023 vq
->private_data
= oldsock
;
1024 vhost_net_enable_vq(n
, vq
);
1026 vhost_net_ubuf_put_wait_and_free(ubufs
);
1030 mutex_unlock(&vq
->mutex
);
1032 mutex_unlock(&n
->dev
.mutex
);
1036 static long vhost_net_reset_owner(struct vhost_net
*n
)
1038 struct socket
*tx_sock
= NULL
;
1039 struct socket
*rx_sock
= NULL
;
1041 struct vhost_memory
*memory
;
1043 mutex_lock(&n
->dev
.mutex
);
1044 err
= vhost_dev_check_owner(&n
->dev
);
1047 memory
= vhost_dev_reset_owner_prepare();
1052 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
1054 vhost_dev_reset_owner(&n
->dev
, memory
);
1055 vhost_net_vq_reset(n
);
1057 mutex_unlock(&n
->dev
.mutex
);
1059 sockfd_put(tx_sock
);
1061 sockfd_put(rx_sock
);
1065 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
1067 size_t vhost_hlen
, sock_hlen
, hdr_len
;
1070 hdr_len
= (features
& ((1ULL << VIRTIO_NET_F_MRG_RXBUF
) |
1071 (1ULL << VIRTIO_F_VERSION_1
))) ?
1072 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
1073 sizeof(struct virtio_net_hdr
);
1074 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
1075 /* vhost provides vnet_hdr */
1076 vhost_hlen
= hdr_len
;
1079 /* socket provides vnet_hdr */
1081 sock_hlen
= hdr_len
;
1083 mutex_lock(&n
->dev
.mutex
);
1084 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
1085 !vhost_log_access_ok(&n
->dev
)) {
1086 mutex_unlock(&n
->dev
.mutex
);
1089 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
1090 mutex_lock(&n
->vqs
[i
].vq
.mutex
);
1091 n
->vqs
[i
].vq
.acked_features
= features
;
1092 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
1093 n
->vqs
[i
].sock_hlen
= sock_hlen
;
1094 mutex_unlock(&n
->vqs
[i
].vq
.mutex
);
1096 mutex_unlock(&n
->dev
.mutex
);
1100 static long vhost_net_set_owner(struct vhost_net
*n
)
1104 mutex_lock(&n
->dev
.mutex
);
1105 if (vhost_dev_has_owner(&n
->dev
)) {
1109 r
= vhost_net_set_ubuf_info(n
);
1112 r
= vhost_dev_set_owner(&n
->dev
);
1114 vhost_net_clear_ubuf_info(n
);
1117 mutex_unlock(&n
->dev
.mutex
);
1121 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
1124 struct vhost_net
*n
= f
->private_data
;
1125 void __user
*argp
= (void __user
*)arg
;
1126 u64 __user
*featurep
= argp
;
1127 struct vhost_vring_file backend
;
1132 case VHOST_NET_SET_BACKEND
:
1133 if (copy_from_user(&backend
, argp
, sizeof backend
))
1135 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
1136 case VHOST_GET_FEATURES
:
1137 features
= VHOST_NET_FEATURES
;
1138 if (copy_to_user(featurep
, &features
, sizeof features
))
1141 case VHOST_SET_FEATURES
:
1142 if (copy_from_user(&features
, featurep
, sizeof features
))
1144 if (features
& ~VHOST_NET_FEATURES
)
1146 return vhost_net_set_features(n
, features
);
1147 case VHOST_RESET_OWNER
:
1148 return vhost_net_reset_owner(n
);
1149 case VHOST_SET_OWNER
:
1150 return vhost_net_set_owner(n
);
1152 mutex_lock(&n
->dev
.mutex
);
1153 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, argp
);
1154 if (r
== -ENOIOCTLCMD
)
1155 r
= vhost_vring_ioctl(&n
->dev
, ioctl
, argp
);
1158 mutex_unlock(&n
->dev
.mutex
);
1163 #ifdef CONFIG_COMPAT
1164 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
1167 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
1171 static const struct file_operations vhost_net_fops
= {
1172 .owner
= THIS_MODULE
,
1173 .release
= vhost_net_release
,
1174 .unlocked_ioctl
= vhost_net_ioctl
,
1175 #ifdef CONFIG_COMPAT
1176 .compat_ioctl
= vhost_net_compat_ioctl
,
1178 .open
= vhost_net_open
,
1179 .llseek
= noop_llseek
,
1182 static struct miscdevice vhost_net_misc
= {
1183 .minor
= VHOST_NET_MINOR
,
1184 .name
= "vhost-net",
1185 .fops
= &vhost_net_fops
,
1188 static int vhost_net_init(void)
1190 if (experimental_zcopytx
)
1191 vhost_net_enable_zcopy(VHOST_NET_VQ_TX
);
1192 return misc_register(&vhost_net_misc
);
1194 module_init(vhost_net_init
);
1196 static void vhost_net_exit(void)
1198 misc_deregister(&vhost_net_misc
);
1200 module_exit(vhost_net_exit
);
1202 MODULE_VERSION("0.0.1");
1203 MODULE_LICENSE("GPL v2");
1204 MODULE_AUTHOR("Michael S. Tsirkin");
1205 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1206 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
1207 MODULE_ALIAS("devname:vhost-net");