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 socket
*sock
= sk
->sk_socket
;
485 struct sk_buff
*head
;
489 if (sock
->ops
->peek_len
)
490 return sock
->ops
->peek_len(sock
);
492 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
493 head
= skb_peek(&sk
->sk_receive_queue
);
496 if (skb_vlan_tag_present(head
))
500 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
504 static int sk_has_rx_data(struct sock
*sk
)
506 struct socket
*sock
= sk
->sk_socket
;
508 if (sock
->ops
->peek_len
)
509 return sock
->ops
->peek_len(sock
);
511 return skb_queue_empty(&sk
->sk_receive_queue
);
514 static int vhost_net_rx_peek_head_len(struct vhost_net
*net
, struct sock
*sk
)
516 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
517 struct vhost_virtqueue
*vq
= &nvq
->vq
;
518 unsigned long uninitialized_var(endtime
);
519 int len
= peek_head_len(sk
);
521 if (!len
&& vq
->busyloop_timeout
) {
522 /* Both tx vq and rx socket were polled here */
523 mutex_lock(&vq
->mutex
);
524 vhost_disable_notify(&net
->dev
, vq
);
527 endtime
= busy_clock() + vq
->busyloop_timeout
;
529 while (vhost_can_busy_poll(&net
->dev
, endtime
) &&
530 !sk_has_rx_data(sk
) &&
531 vhost_vq_avail_empty(&net
->dev
, vq
))
532 cpu_relax_lowlatency();
536 if (vhost_enable_notify(&net
->dev
, vq
))
537 vhost_poll_queue(&vq
->poll
);
538 mutex_unlock(&vq
->mutex
);
540 len
= peek_head_len(sk
);
546 /* This is a multi-buffer version of vhost_get_desc, that works if
547 * vq has read descriptors only.
548 * @vq - the relevant virtqueue
549 * @datalen - data length we'll be reading
550 * @iovcount - returned count of io vectors we fill
552 * @log_num - log offset
553 * @quota - headcount quota, 1 for big buffer
554 * returns number of buffer heads allocated, negative on error
556 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
557 struct vring_used_elem
*heads
,
560 struct vhost_log
*log
,
564 unsigned int out
, in
;
569 /* len is always initialized before use since we are always called with
572 u32
uninitialized_var(len
);
574 while (datalen
> 0 && headcount
< quota
) {
575 if (unlikely(seg
>= UIO_MAXIOV
)) {
579 r
= vhost_get_vq_desc(vq
, vq
->iov
+ seg
,
580 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
590 if (unlikely(out
|| in
<= 0)) {
591 vq_err(vq
, "unexpected descriptor format for RX: "
592 "out %d, in %d\n", out
, in
);
600 heads
[headcount
].id
= cpu_to_vhost32(vq
, d
);
601 len
= iov_length(vq
->iov
+ seg
, in
);
602 heads
[headcount
].len
= cpu_to_vhost32(vq
, len
);
607 heads
[headcount
- 1].len
= cpu_to_vhost32(vq
, len
+ datalen
);
613 if (unlikely(datalen
> 0)) {
619 vhost_discard_vq_desc(vq
, headcount
);
623 /* Expects to be always run from workqueue - which acts as
624 * read-size critical section for our kind of RCU. */
625 static void handle_rx(struct vhost_net
*net
)
627 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
628 struct vhost_virtqueue
*vq
= &nvq
->vq
;
629 unsigned uninitialized_var(in
), log
;
630 struct vhost_log
*vq_log
;
631 struct msghdr msg
= {
634 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
636 .msg_flags
= MSG_DONTWAIT
,
638 struct virtio_net_hdr hdr
= {
640 .gso_type
= VIRTIO_NET_HDR_GSO_NONE
642 size_t total_len
= 0;
645 size_t vhost_hlen
, sock_hlen
;
646 size_t vhost_len
, sock_len
;
648 struct iov_iter fixup
;
649 __virtio16 num_buffers
;
651 mutex_lock(&vq
->mutex
);
652 sock
= vq
->private_data
;
655 vhost_disable_notify(&net
->dev
, vq
);
656 vhost_net_disable_vq(net
, vq
);
658 vhost_hlen
= nvq
->vhost_hlen
;
659 sock_hlen
= nvq
->sock_hlen
;
661 vq_log
= unlikely(vhost_has_feature(vq
, VHOST_F_LOG_ALL
)) ?
663 mergeable
= vhost_has_feature(vq
, VIRTIO_NET_F_MRG_RXBUF
);
665 while ((sock_len
= vhost_net_rx_peek_head_len(net
, sock
->sk
))) {
666 sock_len
+= sock_hlen
;
667 vhost_len
= sock_len
+ vhost_hlen
;
668 headcount
= get_rx_bufs(vq
, vq
->heads
, vhost_len
,
670 likely(mergeable
) ? UIO_MAXIOV
: 1);
671 /* On error, stop handling until the next kick. */
672 if (unlikely(headcount
< 0))
674 /* On overrun, truncate and discard */
675 if (unlikely(headcount
> UIO_MAXIOV
)) {
676 iov_iter_init(&msg
.msg_iter
, READ
, vq
->iov
, 1, 1);
677 err
= sock
->ops
->recvmsg(sock
, &msg
,
678 1, MSG_DONTWAIT
| MSG_TRUNC
);
679 pr_debug("Discarded rx packet: len %zd\n", sock_len
);
682 /* OK, now we need to know about added descriptors. */
684 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
685 /* They have slipped one in as we were
686 * doing that: check again. */
687 vhost_disable_notify(&net
->dev
, vq
);
690 /* Nothing new? Wait for eventfd to tell us
694 /* We don't need to be notified again. */
695 iov_iter_init(&msg
.msg_iter
, READ
, vq
->iov
, in
, vhost_len
);
696 fixup
= msg
.msg_iter
;
697 if (unlikely((vhost_hlen
))) {
698 /* We will supply the header ourselves
701 iov_iter_advance(&msg
.msg_iter
, vhost_hlen
);
703 err
= sock
->ops
->recvmsg(sock
, &msg
,
704 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
705 /* Userspace might have consumed the packet meanwhile:
706 * it's not supposed to do this usually, but might be hard
707 * to prevent. Discard data we got (if any) and keep going. */
708 if (unlikely(err
!= sock_len
)) {
709 pr_debug("Discarded rx packet: "
710 " len %d, expected %zd\n", err
, sock_len
);
711 vhost_discard_vq_desc(vq
, headcount
);
714 /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
715 if (unlikely(vhost_hlen
)) {
716 if (copy_to_iter(&hdr
, sizeof(hdr
),
717 &fixup
) != sizeof(hdr
)) {
718 vq_err(vq
, "Unable to write vnet_hdr "
719 "at addr %p\n", vq
->iov
->iov_base
);
723 /* Header came from socket; we'll need to patch
724 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF
726 iov_iter_advance(&fixup
, sizeof(hdr
));
728 /* TODO: Should check and handle checksum. */
730 num_buffers
= cpu_to_vhost16(vq
, headcount
);
731 if (likely(mergeable
) &&
732 copy_to_iter(&num_buffers
, sizeof num_buffers
,
733 &fixup
) != sizeof num_buffers
) {
734 vq_err(vq
, "Failed num_buffers write");
735 vhost_discard_vq_desc(vq
, headcount
);
738 vhost_add_used_and_signal_n(&net
->dev
, vq
, vq
->heads
,
740 if (unlikely(vq_log
))
741 vhost_log_write(vq
, vq_log
, log
, vhost_len
);
742 total_len
+= vhost_len
;
743 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
744 vhost_poll_queue(&vq
->poll
);
748 vhost_net_enable_vq(net
, vq
);
750 mutex_unlock(&vq
->mutex
);
753 static void handle_tx_kick(struct vhost_work
*work
)
755 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
757 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
762 static void handle_rx_kick(struct vhost_work
*work
)
764 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
766 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
771 static void handle_tx_net(struct vhost_work
*work
)
773 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
774 poll
[VHOST_NET_VQ_TX
].work
);
778 static void handle_rx_net(struct vhost_work
*work
)
780 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
781 poll
[VHOST_NET_VQ_RX
].work
);
785 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
788 struct vhost_dev
*dev
;
789 struct vhost_virtqueue
**vqs
;
792 n
= kmalloc(sizeof *n
, GFP_KERNEL
| __GFP_NOWARN
| __GFP_REPEAT
);
794 n
= vmalloc(sizeof *n
);
798 vqs
= kmalloc(VHOST_NET_VQ_MAX
* sizeof(*vqs
), GFP_KERNEL
);
805 vqs
[VHOST_NET_VQ_TX
] = &n
->vqs
[VHOST_NET_VQ_TX
].vq
;
806 vqs
[VHOST_NET_VQ_RX
] = &n
->vqs
[VHOST_NET_VQ_RX
].vq
;
807 n
->vqs
[VHOST_NET_VQ_TX
].vq
.handle_kick
= handle_tx_kick
;
808 n
->vqs
[VHOST_NET_VQ_RX
].vq
.handle_kick
= handle_rx_kick
;
809 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
810 n
->vqs
[i
].ubufs
= NULL
;
811 n
->vqs
[i
].ubuf_info
= NULL
;
812 n
->vqs
[i
].upend_idx
= 0;
813 n
->vqs
[i
].done_idx
= 0;
814 n
->vqs
[i
].vhost_hlen
= 0;
815 n
->vqs
[i
].sock_hlen
= 0;
817 vhost_dev_init(dev
, vqs
, VHOST_NET_VQ_MAX
);
819 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, POLLOUT
, dev
);
820 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, POLLIN
, dev
);
827 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
828 struct vhost_virtqueue
*vq
)
832 mutex_lock(&vq
->mutex
);
833 sock
= vq
->private_data
;
834 vhost_net_disable_vq(n
, vq
);
835 vq
->private_data
= NULL
;
836 mutex_unlock(&vq
->mutex
);
840 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
841 struct socket
**rx_sock
)
843 *tx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_TX
].vq
);
844 *rx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_RX
].vq
);
847 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
849 vhost_poll_flush(n
->poll
+ index
);
850 vhost_poll_flush(&n
->vqs
[index
].vq
.poll
);
853 static void vhost_net_flush(struct vhost_net
*n
)
855 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
856 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
857 if (n
->vqs
[VHOST_NET_VQ_TX
].ubufs
) {
858 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
860 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
861 /* Wait for all lower device DMAs done. */
862 vhost_net_ubuf_put_and_wait(n
->vqs
[VHOST_NET_VQ_TX
].ubufs
);
863 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
865 atomic_set(&n
->vqs
[VHOST_NET_VQ_TX
].ubufs
->refcount
, 1);
866 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
870 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
872 struct vhost_net
*n
= f
->private_data
;
873 struct socket
*tx_sock
;
874 struct socket
*rx_sock
;
876 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
878 vhost_dev_stop(&n
->dev
);
879 vhost_dev_cleanup(&n
->dev
, false);
880 vhost_net_vq_reset(n
);
885 /* Make sure no callbacks are outstanding */
886 synchronize_rcu_bh();
887 /* We do an extra flush before freeing memory,
888 * since jobs can re-queue themselves. */
895 static struct socket
*get_raw_socket(int fd
)
898 struct sockaddr_ll sa
;
899 char buf
[MAX_ADDR_LEN
];
901 int uaddr_len
= sizeof uaddr
, r
;
902 struct socket
*sock
= sockfd_lookup(fd
, &r
);
905 return ERR_PTR(-ENOTSOCK
);
907 /* Parameter checking */
908 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
909 r
= -ESOCKTNOSUPPORT
;
913 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
,
918 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
928 static struct socket
*get_tap_socket(int fd
)
930 struct file
*file
= fget(fd
);
934 return ERR_PTR(-EBADF
);
935 sock
= tun_get_socket(file
);
938 sock
= macvtap_get_socket(file
);
944 static struct socket
*get_socket(int fd
)
948 /* special case to disable backend */
951 sock
= get_raw_socket(fd
);
954 sock
= get_tap_socket(fd
);
957 return ERR_PTR(-ENOTSOCK
);
960 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
962 struct socket
*sock
, *oldsock
;
963 struct vhost_virtqueue
*vq
;
964 struct vhost_net_virtqueue
*nvq
;
965 struct vhost_net_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
968 mutex_lock(&n
->dev
.mutex
);
969 r
= vhost_dev_check_owner(&n
->dev
);
973 if (index
>= VHOST_NET_VQ_MAX
) {
977 vq
= &n
->vqs
[index
].vq
;
978 nvq
= &n
->vqs
[index
];
979 mutex_lock(&vq
->mutex
);
981 /* Verify that ring has been setup correctly. */
982 if (!vhost_vq_access_ok(vq
)) {
986 sock
= get_socket(fd
);
992 /* start polling new socket */
993 oldsock
= vq
->private_data
;
994 if (sock
!= oldsock
) {
995 ubufs
= vhost_net_ubuf_alloc(vq
,
996 sock
&& vhost_sock_zcopy(sock
));
1002 vhost_net_disable_vq(n
, vq
);
1003 vq
->private_data
= sock
;
1004 r
= vhost_vq_init_access(vq
);
1007 r
= vhost_net_enable_vq(n
, vq
);
1011 oldubufs
= nvq
->ubufs
;
1015 n
->tx_zcopy_err
= 0;
1016 n
->tx_flush
= false;
1019 mutex_unlock(&vq
->mutex
);
1022 vhost_net_ubuf_put_wait_and_free(oldubufs
);
1023 mutex_lock(&vq
->mutex
);
1024 vhost_zerocopy_signal_used(n
, vq
);
1025 mutex_unlock(&vq
->mutex
);
1029 vhost_net_flush_vq(n
, index
);
1030 sockfd_put(oldsock
);
1033 mutex_unlock(&n
->dev
.mutex
);
1037 vq
->private_data
= oldsock
;
1038 vhost_net_enable_vq(n
, vq
);
1040 vhost_net_ubuf_put_wait_and_free(ubufs
);
1044 mutex_unlock(&vq
->mutex
);
1046 mutex_unlock(&n
->dev
.mutex
);
1050 static long vhost_net_reset_owner(struct vhost_net
*n
)
1052 struct socket
*tx_sock
= NULL
;
1053 struct socket
*rx_sock
= NULL
;
1055 struct vhost_memory
*memory
;
1057 mutex_lock(&n
->dev
.mutex
);
1058 err
= vhost_dev_check_owner(&n
->dev
);
1061 memory
= vhost_dev_reset_owner_prepare();
1066 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
1068 vhost_dev_reset_owner(&n
->dev
, memory
);
1069 vhost_net_vq_reset(n
);
1071 mutex_unlock(&n
->dev
.mutex
);
1073 sockfd_put(tx_sock
);
1075 sockfd_put(rx_sock
);
1079 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
1081 size_t vhost_hlen
, sock_hlen
, hdr_len
;
1084 hdr_len
= (features
& ((1ULL << VIRTIO_NET_F_MRG_RXBUF
) |
1085 (1ULL << VIRTIO_F_VERSION_1
))) ?
1086 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
1087 sizeof(struct virtio_net_hdr
);
1088 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
1089 /* vhost provides vnet_hdr */
1090 vhost_hlen
= hdr_len
;
1093 /* socket provides vnet_hdr */
1095 sock_hlen
= hdr_len
;
1097 mutex_lock(&n
->dev
.mutex
);
1098 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
1099 !vhost_log_access_ok(&n
->dev
)) {
1100 mutex_unlock(&n
->dev
.mutex
);
1103 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
1104 mutex_lock(&n
->vqs
[i
].vq
.mutex
);
1105 n
->vqs
[i
].vq
.acked_features
= features
;
1106 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
1107 n
->vqs
[i
].sock_hlen
= sock_hlen
;
1108 mutex_unlock(&n
->vqs
[i
].vq
.mutex
);
1110 mutex_unlock(&n
->dev
.mutex
);
1114 static long vhost_net_set_owner(struct vhost_net
*n
)
1118 mutex_lock(&n
->dev
.mutex
);
1119 if (vhost_dev_has_owner(&n
->dev
)) {
1123 r
= vhost_net_set_ubuf_info(n
);
1126 r
= vhost_dev_set_owner(&n
->dev
);
1128 vhost_net_clear_ubuf_info(n
);
1131 mutex_unlock(&n
->dev
.mutex
);
1135 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
1138 struct vhost_net
*n
= f
->private_data
;
1139 void __user
*argp
= (void __user
*)arg
;
1140 u64 __user
*featurep
= argp
;
1141 struct vhost_vring_file backend
;
1146 case VHOST_NET_SET_BACKEND
:
1147 if (copy_from_user(&backend
, argp
, sizeof backend
))
1149 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
1150 case VHOST_GET_FEATURES
:
1151 features
= VHOST_NET_FEATURES
;
1152 if (copy_to_user(featurep
, &features
, sizeof features
))
1155 case VHOST_SET_FEATURES
:
1156 if (copy_from_user(&features
, featurep
, sizeof features
))
1158 if (features
& ~VHOST_NET_FEATURES
)
1160 return vhost_net_set_features(n
, features
);
1161 case VHOST_RESET_OWNER
:
1162 return vhost_net_reset_owner(n
);
1163 case VHOST_SET_OWNER
:
1164 return vhost_net_set_owner(n
);
1166 mutex_lock(&n
->dev
.mutex
);
1167 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, argp
);
1168 if (r
== -ENOIOCTLCMD
)
1169 r
= vhost_vring_ioctl(&n
->dev
, ioctl
, argp
);
1172 mutex_unlock(&n
->dev
.mutex
);
1177 #ifdef CONFIG_COMPAT
1178 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
1181 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
1185 static const struct file_operations vhost_net_fops
= {
1186 .owner
= THIS_MODULE
,
1187 .release
= vhost_net_release
,
1188 .unlocked_ioctl
= vhost_net_ioctl
,
1189 #ifdef CONFIG_COMPAT
1190 .compat_ioctl
= vhost_net_compat_ioctl
,
1192 .open
= vhost_net_open
,
1193 .llseek
= noop_llseek
,
1196 static struct miscdevice vhost_net_misc
= {
1197 .minor
= VHOST_NET_MINOR
,
1198 .name
= "vhost-net",
1199 .fops
= &vhost_net_fops
,
1202 static int vhost_net_init(void)
1204 if (experimental_zcopytx
)
1205 vhost_net_enable_zcopy(VHOST_NET_VQ_TX
);
1206 return misc_register(&vhost_net_misc
);
1208 module_init(vhost_net_init
);
1210 static void vhost_net_exit(void)
1212 misc_deregister(&vhost_net_misc
);
1214 module_exit(vhost_net_exit
);
1216 MODULE_VERSION("0.0.1");
1217 MODULE_LICENSE("GPL v2");
1218 MODULE_AUTHOR("Michael S. Tsirkin");
1219 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1220 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
1221 MODULE_ALIAS("devname:vhost-net");