1 /* Copyright (C) 2009 Red Hat, Inc.
2 * Author: Michael S. Tsirkin <mst@redhat.com>
4 * This work is licensed under the terms of the GNU GPL, version 2.
6 * virtio-net server in host kernel.
9 #include <linux/compat.h>
10 #include <linux/eventfd.h>
11 #include <linux/vhost.h>
12 #include <linux/virtio_net.h>
13 #include <linux/miscdevice.h>
14 #include <linux/module.h>
15 #include <linux/moduleparam.h>
16 #include <linux/mutex.h>
17 #include <linux/workqueue.h>
18 #include <linux/file.h>
19 #include <linux/slab.h>
21 #include <linux/net.h>
22 #include <linux/if_packet.h>
23 #include <linux/if_arp.h>
24 #include <linux/if_tun.h>
25 #include <linux/if_macvlan.h>
26 #include <linux/if_vlan.h>
32 static int experimental_zcopytx
= 1;
33 module_param(experimental_zcopytx
, int, 0444);
34 MODULE_PARM_DESC(experimental_zcopytx
, "Enable Zero Copy TX;"
35 " 1 -Enable; 0 - Disable");
37 /* Max number of bytes transferred before requeueing the job.
38 * Using this limit prevents one virtqueue from starving others. */
39 #define VHOST_NET_WEIGHT 0x80000
41 /* MAX number of TX used buffers for outstanding zerocopy */
42 #define VHOST_MAX_PEND 128
43 #define VHOST_GOODCOPY_LEN 256
46 * For transmit, used buffer len is unused; we override it to track buffer
47 * status internally; used for zerocopy tx only.
49 /* Lower device DMA failed */
50 #define VHOST_DMA_FAILED_LEN 3
51 /* Lower device DMA done */
52 #define VHOST_DMA_DONE_LEN 2
53 /* Lower device DMA in progress */
54 #define VHOST_DMA_IN_PROGRESS 1
56 #define VHOST_DMA_CLEAR_LEN 0
58 #define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN)
61 VHOST_NET_FEATURES
= VHOST_FEATURES
|
62 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR
) |
63 (1ULL << VIRTIO_NET_F_MRG_RXBUF
),
72 struct vhost_net_ubuf_ref
{
74 wait_queue_head_t wait
;
75 struct vhost_virtqueue
*vq
;
78 struct vhost_net_virtqueue
{
79 struct vhost_virtqueue vq
;
80 /* hdr is used to store the virtio header.
81 * Since each iovec has >= 1 byte length, we never need more than
82 * header length entries to store the header. */
83 struct iovec hdr
[sizeof(struct virtio_net_hdr_mrg_rxbuf
)];
86 /* vhost zerocopy support fields below: */
87 /* last used idx for outstanding DMA zerocopy buffers */
89 /* first used idx for DMA done zerocopy buffers */
91 /* an array of userspace buffers info */
92 struct ubuf_info
*ubuf_info
;
93 /* Reference counting for outstanding ubufs.
94 * Protected by vq mutex. Writers must also take device mutex. */
95 struct vhost_net_ubuf_ref
*ubufs
;
100 struct vhost_net_virtqueue vqs
[VHOST_NET_VQ_MAX
];
101 struct vhost_poll poll
[VHOST_NET_VQ_MAX
];
102 /* Number of TX recently submitted.
103 * Protected by tx vq lock. */
105 /* Number of times zerocopy TX recently failed.
106 * Protected by tx vq lock. */
107 unsigned tx_zcopy_err
;
108 /* Flush in progress. Protected by tx vq lock. */
112 static unsigned vhost_net_zcopy_mask __read_mostly
;
114 static void vhost_net_enable_zcopy(int vq
)
116 vhost_net_zcopy_mask
|= 0x1 << vq
;
119 static void vhost_net_zerocopy_done_signal(struct kref
*kref
)
121 struct vhost_net_ubuf_ref
*ubufs
;
123 ubufs
= container_of(kref
, struct vhost_net_ubuf_ref
, kref
);
124 wake_up(&ubufs
->wait
);
127 static struct vhost_net_ubuf_ref
*
128 vhost_net_ubuf_alloc(struct vhost_virtqueue
*vq
, bool zcopy
)
130 struct vhost_net_ubuf_ref
*ubufs
;
131 /* No zero copy backend? Nothing to count. */
134 ubufs
= kmalloc(sizeof(*ubufs
), GFP_KERNEL
);
136 return ERR_PTR(-ENOMEM
);
137 kref_init(&ubufs
->kref
);
138 init_waitqueue_head(&ubufs
->wait
);
143 static void vhost_net_ubuf_put(struct vhost_net_ubuf_ref
*ubufs
)
145 kref_put(&ubufs
->kref
, vhost_net_zerocopy_done_signal
);
148 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref
*ubufs
)
150 kref_put(&ubufs
->kref
, vhost_net_zerocopy_done_signal
);
151 wait_event(ubufs
->wait
, !atomic_read(&ubufs
->kref
.refcount
));
154 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref
*ubufs
)
156 vhost_net_ubuf_put_and_wait(ubufs
);
160 static void vhost_net_clear_ubuf_info(struct vhost_net
*n
)
164 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
165 kfree(n
->vqs
[i
].ubuf_info
);
166 n
->vqs
[i
].ubuf_info
= NULL
;
170 static int vhost_net_set_ubuf_info(struct vhost_net
*n
)
175 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
176 zcopy
= vhost_net_zcopy_mask
& (0x1 << i
);
179 n
->vqs
[i
].ubuf_info
= kmalloc(sizeof(*n
->vqs
[i
].ubuf_info
) *
180 UIO_MAXIOV
, GFP_KERNEL
);
181 if (!n
->vqs
[i
].ubuf_info
)
187 vhost_net_clear_ubuf_info(n
);
191 static void vhost_net_vq_reset(struct vhost_net
*n
)
195 vhost_net_clear_ubuf_info(n
);
197 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
198 n
->vqs
[i
].done_idx
= 0;
199 n
->vqs
[i
].upend_idx
= 0;
200 n
->vqs
[i
].ubufs
= NULL
;
201 n
->vqs
[i
].vhost_hlen
= 0;
202 n
->vqs
[i
].sock_hlen
= 0;
207 static void vhost_net_tx_packet(struct vhost_net
*net
)
210 if (net
->tx_packets
< 1024)
213 net
->tx_zcopy_err
= 0;
216 static void vhost_net_tx_err(struct vhost_net
*net
)
221 static bool vhost_net_tx_select_zcopy(struct vhost_net
*net
)
223 /* TX flush waits for outstanding DMAs to be done.
224 * Don't start new DMAs.
226 return !net
->tx_flush
&&
227 net
->tx_packets
/ 64 >= net
->tx_zcopy_err
;
230 static bool vhost_sock_zcopy(struct socket
*sock
)
232 return unlikely(experimental_zcopytx
) &&
233 sock_flag(sock
->sk
, SOCK_ZEROCOPY
);
236 /* Pop first len bytes from iovec. Return number of segments used. */
237 static int move_iovec_hdr(struct iovec
*from
, struct iovec
*to
,
238 size_t len
, int iov_count
)
243 while (len
&& seg
< iov_count
) {
244 size
= min(from
->iov_len
, len
);
245 to
->iov_base
= from
->iov_base
;
247 from
->iov_len
-= size
;
248 from
->iov_base
+= size
;
256 /* Copy iovec entries for len bytes from iovec. */
257 static void copy_iovec_hdr(const struct iovec
*from
, struct iovec
*to
,
258 size_t len
, int iovcount
)
263 while (len
&& seg
< iovcount
) {
264 size
= min(from
->iov_len
, len
);
265 to
->iov_base
= from
->iov_base
;
274 /* In case of DMA done not in order in lower device driver for some reason.
275 * upend_idx is used to track end of used idx, done_idx is used to track head
276 * of used idx. Once lower device DMA done contiguously, we will signal KVM
279 static 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
;
309 int cnt
= atomic_read(&ubufs
->kref
.refcount
);
311 /* set len to mark this desc buffers done DMA */
312 vq
->heads
[ubuf
->desc
].len
= success
?
313 VHOST_DMA_DONE_LEN
: VHOST_DMA_FAILED_LEN
;
314 vhost_net_ubuf_put(ubufs
);
317 * Trigger polling thread if guest stopped submitting new buffers:
318 * in this case, the refcount after decrement will eventually reach 1
320 * We also trigger polling periodically after each 16 packets
321 * (the value 16 here is more or less arbitrary, it's tuned to trigger
322 * less than 10% of times).
324 if (cnt
<= 2 || !(cnt
% 16))
325 vhost_poll_queue(&vq
->poll
);
328 /* Expects to be always run from workqueue - which acts as
329 * read-size critical section for our kind of RCU. */
330 static void handle_tx(struct vhost_net
*net
)
332 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
333 struct vhost_virtqueue
*vq
= &nvq
->vq
;
336 struct msghdr msg
= {
342 .msg_flags
= MSG_DONTWAIT
,
344 size_t len
, total_len
= 0;
348 struct vhost_net_ubuf_ref
*uninitialized_var(ubufs
);
349 bool zcopy
, zcopy_used
;
351 mutex_lock(&vq
->mutex
);
352 sock
= vq
->private_data
;
356 vhost_disable_notify(&net
->dev
, vq
);
358 hdr_size
= nvq
->vhost_hlen
;
362 /* Release DMAs done buffers first */
364 vhost_zerocopy_signal_used(net
, vq
);
366 /* If more outstanding DMAs, queue the work.
367 * Handle upend_idx wrap around
369 if (unlikely((nvq
->upend_idx
+ vq
->num
- VHOST_MAX_PEND
)
370 % UIO_MAXIOV
== nvq
->done_idx
))
373 head
= vhost_get_vq_desc(&net
->dev
, vq
, vq
->iov
,
377 /* On error, stop handling until the next kick. */
378 if (unlikely(head
< 0))
380 /* Nothing new? Wait for eventfd to tell us they refilled. */
381 if (head
== vq
->num
) {
382 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
383 vhost_disable_notify(&net
->dev
, vq
);
389 vq_err(vq
, "Unexpected descriptor format for TX: "
390 "out %d, int %d\n", out
, in
);
393 /* Skip header. TODO: support TSO. */
394 s
= move_iovec_hdr(vq
->iov
, nvq
->hdr
, hdr_size
, out
);
395 msg
.msg_iovlen
= out
;
396 len
= iov_length(vq
->iov
, out
);
399 vq_err(vq
, "Unexpected header len for TX: "
400 "%zd expected %zd\n",
401 iov_length(nvq
->hdr
, s
), hdr_size
);
405 zcopy_used
= zcopy
&& len
>= VHOST_GOODCOPY_LEN
406 && (nvq
->upend_idx
+ 1) % UIO_MAXIOV
!=
408 && vhost_net_tx_select_zcopy(net
);
410 /* use msg_control to pass vhost zerocopy ubuf info to skb */
412 struct ubuf_info
*ubuf
;
413 ubuf
= nvq
->ubuf_info
+ nvq
->upend_idx
;
415 vq
->heads
[nvq
->upend_idx
].id
= head
;
416 vq
->heads
[nvq
->upend_idx
].len
= VHOST_DMA_IN_PROGRESS
;
417 ubuf
->callback
= vhost_zerocopy_callback
;
418 ubuf
->ctx
= nvq
->ubufs
;
419 ubuf
->desc
= nvq
->upend_idx
;
420 msg
.msg_control
= ubuf
;
421 msg
.msg_controllen
= sizeof(ubuf
);
423 kref_get(&ubufs
->kref
);
424 nvq
->upend_idx
= (nvq
->upend_idx
+ 1) % UIO_MAXIOV
;
426 msg
.msg_control
= NULL
;
429 /* TODO: Check specific error and bomb out unless ENOBUFS? */
430 err
= sock
->ops
->sendmsg(NULL
, sock
, &msg
, len
);
431 if (unlikely(err
< 0)) {
433 vhost_net_ubuf_put(ubufs
);
434 nvq
->upend_idx
= ((unsigned)nvq
->upend_idx
- 1)
437 vhost_discard_vq_desc(vq
, 1);
441 pr_debug("Truncated TX packet: "
442 " len %d != %zd\n", err
, len
);
444 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
446 vhost_zerocopy_signal_used(net
, vq
);
448 vhost_net_tx_packet(net
);
449 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
450 vhost_poll_queue(&vq
->poll
);
455 mutex_unlock(&vq
->mutex
);
458 static int peek_head_len(struct sock
*sk
)
460 struct sk_buff
*head
;
464 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
465 head
= skb_peek(&sk
->sk_receive_queue
);
468 if (vlan_tx_tag_present(head
))
472 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
476 /* This is a multi-buffer version of vhost_get_desc, that works if
477 * vq has read descriptors only.
478 * @vq - the relevant virtqueue
479 * @datalen - data length we'll be reading
480 * @iovcount - returned count of io vectors we fill
482 * @log_num - log offset
483 * @quota - headcount quota, 1 for big buffer
484 * returns number of buffer heads allocated, negative on error
486 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
487 struct vring_used_elem
*heads
,
490 struct vhost_log
*log
,
494 unsigned int out
, in
;
500 while (datalen
> 0 && headcount
< quota
) {
501 if (unlikely(seg
>= UIO_MAXIOV
)) {
505 d
= vhost_get_vq_desc(vq
->dev
, vq
, vq
->iov
+ seg
,
506 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
512 if (unlikely(out
|| in
<= 0)) {
513 vq_err(vq
, "unexpected descriptor format for RX: "
514 "out %d, in %d\n", out
, in
);
522 heads
[headcount
].id
= d
;
523 heads
[headcount
].len
= iov_length(vq
->iov
+ seg
, in
);
524 datalen
-= heads
[headcount
].len
;
528 heads
[headcount
- 1].len
+= datalen
;
534 vhost_discard_vq_desc(vq
, headcount
);
538 /* Expects to be always run from workqueue - which acts as
539 * read-size critical section for our kind of RCU. */
540 static void handle_rx(struct vhost_net
*net
)
542 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
543 struct vhost_virtqueue
*vq
= &nvq
->vq
;
544 unsigned uninitialized_var(in
), log
;
545 struct vhost_log
*vq_log
;
546 struct msghdr msg
= {
549 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
552 .msg_flags
= MSG_DONTWAIT
,
554 struct virtio_net_hdr_mrg_rxbuf hdr
= {
556 .hdr
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
558 size_t total_len
= 0;
561 size_t vhost_hlen
, sock_hlen
;
562 size_t vhost_len
, sock_len
;
565 mutex_lock(&vq
->mutex
);
566 sock
= vq
->private_data
;
569 vhost_disable_notify(&net
->dev
, vq
);
571 vhost_hlen
= nvq
->vhost_hlen
;
572 sock_hlen
= nvq
->sock_hlen
;
574 vq_log
= unlikely(vhost_has_feature(&net
->dev
, VHOST_F_LOG_ALL
)) ?
576 mergeable
= vhost_has_feature(&net
->dev
, VIRTIO_NET_F_MRG_RXBUF
);
578 while ((sock_len
= peek_head_len(sock
->sk
))) {
579 sock_len
+= sock_hlen
;
580 vhost_len
= sock_len
+ vhost_hlen
;
581 headcount
= get_rx_bufs(vq
, vq
->heads
, vhost_len
,
583 likely(mergeable
) ? UIO_MAXIOV
: 1);
584 /* On error, stop handling until the next kick. */
585 if (unlikely(headcount
< 0))
587 /* OK, now we need to know about added descriptors. */
589 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
590 /* They have slipped one in as we were
591 * doing that: check again. */
592 vhost_disable_notify(&net
->dev
, vq
);
595 /* Nothing new? Wait for eventfd to tell us
599 /* We don't need to be notified again. */
600 if (unlikely((vhost_hlen
)))
601 /* Skip header. TODO: support TSO. */
602 move_iovec_hdr(vq
->iov
, nvq
->hdr
, vhost_hlen
, in
);
604 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
605 * needed because recvmsg can modify msg_iov. */
606 copy_iovec_hdr(vq
->iov
, nvq
->hdr
, sock_hlen
, in
);
608 err
= sock
->ops
->recvmsg(NULL
, sock
, &msg
,
609 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
610 /* Userspace might have consumed the packet meanwhile:
611 * it's not supposed to do this usually, but might be hard
612 * to prevent. Discard data we got (if any) and keep going. */
613 if (unlikely(err
!= sock_len
)) {
614 pr_debug("Discarded rx packet: "
615 " len %d, expected %zd\n", err
, sock_len
);
616 vhost_discard_vq_desc(vq
, headcount
);
619 if (unlikely(vhost_hlen
) &&
620 memcpy_toiovecend(nvq
->hdr
, (unsigned char *)&hdr
, 0,
622 vq_err(vq
, "Unable to write vnet_hdr at addr %p\n",
626 /* TODO: Should check and handle checksum. */
627 if (likely(mergeable
) &&
628 memcpy_toiovecend(nvq
->hdr
, (unsigned char *)&headcount
,
629 offsetof(typeof(hdr
), num_buffers
),
630 sizeof hdr
.num_buffers
)) {
631 vq_err(vq
, "Failed num_buffers write");
632 vhost_discard_vq_desc(vq
, headcount
);
635 vhost_add_used_and_signal_n(&net
->dev
, vq
, vq
->heads
,
637 if (unlikely(vq_log
))
638 vhost_log_write(vq
, vq_log
, log
, vhost_len
);
639 total_len
+= vhost_len
;
640 if (unlikely(total_len
>= VHOST_NET_WEIGHT
)) {
641 vhost_poll_queue(&vq
->poll
);
646 mutex_unlock(&vq
->mutex
);
649 static void handle_tx_kick(struct vhost_work
*work
)
651 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
653 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
658 static void handle_rx_kick(struct vhost_work
*work
)
660 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
662 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
667 static void handle_tx_net(struct vhost_work
*work
)
669 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
670 poll
[VHOST_NET_VQ_TX
].work
);
674 static void handle_rx_net(struct vhost_work
*work
)
676 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
677 poll
[VHOST_NET_VQ_RX
].work
);
681 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
683 struct vhost_net
*n
= kmalloc(sizeof *n
, GFP_KERNEL
);
684 struct vhost_dev
*dev
;
685 struct vhost_virtqueue
**vqs
;
690 vqs
= kmalloc(VHOST_NET_VQ_MAX
* sizeof(*vqs
), GFP_KERNEL
);
697 vqs
[VHOST_NET_VQ_TX
] = &n
->vqs
[VHOST_NET_VQ_TX
].vq
;
698 vqs
[VHOST_NET_VQ_RX
] = &n
->vqs
[VHOST_NET_VQ_RX
].vq
;
699 n
->vqs
[VHOST_NET_VQ_TX
].vq
.handle_kick
= handle_tx_kick
;
700 n
->vqs
[VHOST_NET_VQ_RX
].vq
.handle_kick
= handle_rx_kick
;
701 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
702 n
->vqs
[i
].ubufs
= NULL
;
703 n
->vqs
[i
].ubuf_info
= NULL
;
704 n
->vqs
[i
].upend_idx
= 0;
705 n
->vqs
[i
].done_idx
= 0;
706 n
->vqs
[i
].vhost_hlen
= 0;
707 n
->vqs
[i
].sock_hlen
= 0;
709 r
= vhost_dev_init(dev
, vqs
, VHOST_NET_VQ_MAX
);
716 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, POLLOUT
, dev
);
717 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, POLLIN
, dev
);
724 static void vhost_net_disable_vq(struct vhost_net
*n
,
725 struct vhost_virtqueue
*vq
)
727 struct vhost_net_virtqueue
*nvq
=
728 container_of(vq
, struct vhost_net_virtqueue
, vq
);
729 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
730 if (!vq
->private_data
)
732 vhost_poll_stop(poll
);
735 static int vhost_net_enable_vq(struct vhost_net
*n
,
736 struct vhost_virtqueue
*vq
)
738 struct vhost_net_virtqueue
*nvq
=
739 container_of(vq
, struct vhost_net_virtqueue
, vq
);
740 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
743 sock
= vq
->private_data
;
747 return vhost_poll_start(poll
, sock
->file
);
750 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
751 struct vhost_virtqueue
*vq
)
755 mutex_lock(&vq
->mutex
);
756 sock
= vq
->private_data
;
757 vhost_net_disable_vq(n
, vq
);
758 vq
->private_data
= NULL
;
759 mutex_unlock(&vq
->mutex
);
763 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
764 struct socket
**rx_sock
)
766 *tx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_TX
].vq
);
767 *rx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_RX
].vq
);
770 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
772 vhost_poll_flush(n
->poll
+ index
);
773 vhost_poll_flush(&n
->vqs
[index
].vq
.poll
);
776 static void vhost_net_flush(struct vhost_net
*n
)
778 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
779 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
780 if (n
->vqs
[VHOST_NET_VQ_TX
].ubufs
) {
781 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
783 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
784 /* Wait for all lower device DMAs done. */
785 vhost_net_ubuf_put_and_wait(n
->vqs
[VHOST_NET_VQ_TX
].ubufs
);
786 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
788 kref_init(&n
->vqs
[VHOST_NET_VQ_TX
].ubufs
->kref
);
789 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
793 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
795 struct vhost_net
*n
= f
->private_data
;
796 struct socket
*tx_sock
;
797 struct socket
*rx_sock
;
799 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
801 vhost_dev_stop(&n
->dev
);
802 vhost_dev_cleanup(&n
->dev
, false);
803 vhost_net_vq_reset(n
);
808 /* We do an extra flush before freeing memory,
809 * since jobs can re-queue themselves. */
816 static struct socket
*get_raw_socket(int fd
)
819 struct sockaddr_ll sa
;
820 char buf
[MAX_ADDR_LEN
];
822 int uaddr_len
= sizeof uaddr
, r
;
823 struct socket
*sock
= sockfd_lookup(fd
, &r
);
826 return ERR_PTR(-ENOTSOCK
);
828 /* Parameter checking */
829 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
830 r
= -ESOCKTNOSUPPORT
;
834 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
,
839 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
849 static struct socket
*get_tap_socket(int fd
)
851 struct file
*file
= fget(fd
);
855 return ERR_PTR(-EBADF
);
856 sock
= tun_get_socket(file
);
859 sock
= macvtap_get_socket(file
);
865 static struct socket
*get_socket(int fd
)
869 /* special case to disable backend */
872 sock
= get_raw_socket(fd
);
875 sock
= get_tap_socket(fd
);
878 return ERR_PTR(-ENOTSOCK
);
881 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
883 struct socket
*sock
, *oldsock
;
884 struct vhost_virtqueue
*vq
;
885 struct vhost_net_virtqueue
*nvq
;
886 struct vhost_net_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
889 mutex_lock(&n
->dev
.mutex
);
890 r
= vhost_dev_check_owner(&n
->dev
);
894 if (index
>= VHOST_NET_VQ_MAX
) {
898 vq
= &n
->vqs
[index
].vq
;
899 nvq
= &n
->vqs
[index
];
900 mutex_lock(&vq
->mutex
);
902 /* Verify that ring has been setup correctly. */
903 if (!vhost_vq_access_ok(vq
)) {
907 sock
= get_socket(fd
);
913 /* start polling new socket */
914 oldsock
= vq
->private_data
;
915 if (sock
!= oldsock
) {
916 ubufs
= vhost_net_ubuf_alloc(vq
,
917 sock
&& vhost_sock_zcopy(sock
));
923 vhost_net_disable_vq(n
, vq
);
924 vq
->private_data
= sock
;
925 r
= vhost_init_used(vq
);
928 r
= vhost_net_enable_vq(n
, vq
);
932 oldubufs
= nvq
->ubufs
;
940 mutex_unlock(&vq
->mutex
);
943 vhost_net_ubuf_put_wait_and_free(oldubufs
);
944 mutex_lock(&vq
->mutex
);
945 vhost_zerocopy_signal_used(n
, vq
);
946 mutex_unlock(&vq
->mutex
);
950 vhost_net_flush_vq(n
, index
);
954 mutex_unlock(&n
->dev
.mutex
);
958 vq
->private_data
= oldsock
;
959 vhost_net_enable_vq(n
, vq
);
961 vhost_net_ubuf_put_wait_and_free(ubufs
);
965 mutex_unlock(&vq
->mutex
);
967 mutex_unlock(&n
->dev
.mutex
);
971 static long vhost_net_reset_owner(struct vhost_net
*n
)
973 struct socket
*tx_sock
= NULL
;
974 struct socket
*rx_sock
= NULL
;
976 struct vhost_memory
*memory
;
978 mutex_lock(&n
->dev
.mutex
);
979 err
= vhost_dev_check_owner(&n
->dev
);
982 memory
= vhost_dev_reset_owner_prepare();
987 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
989 vhost_dev_reset_owner(&n
->dev
, memory
);
990 vhost_net_vq_reset(n
);
992 mutex_unlock(&n
->dev
.mutex
);
1000 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
1002 size_t vhost_hlen
, sock_hlen
, hdr_len
;
1005 hdr_len
= (features
& (1 << VIRTIO_NET_F_MRG_RXBUF
)) ?
1006 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
1007 sizeof(struct virtio_net_hdr
);
1008 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
1009 /* vhost provides vnet_hdr */
1010 vhost_hlen
= hdr_len
;
1013 /* socket provides vnet_hdr */
1015 sock_hlen
= hdr_len
;
1017 mutex_lock(&n
->dev
.mutex
);
1018 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
1019 !vhost_log_access_ok(&n
->dev
)) {
1020 mutex_unlock(&n
->dev
.mutex
);
1023 n
->dev
.acked_features
= features
;
1025 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
1026 mutex_lock(&n
->vqs
[i
].vq
.mutex
);
1027 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
1028 n
->vqs
[i
].sock_hlen
= sock_hlen
;
1029 mutex_unlock(&n
->vqs
[i
].vq
.mutex
);
1032 mutex_unlock(&n
->dev
.mutex
);
1036 static long vhost_net_set_owner(struct vhost_net
*n
)
1040 mutex_lock(&n
->dev
.mutex
);
1041 if (vhost_dev_has_owner(&n
->dev
)) {
1045 r
= vhost_net_set_ubuf_info(n
);
1048 r
= vhost_dev_set_owner(&n
->dev
);
1050 vhost_net_clear_ubuf_info(n
);
1053 mutex_unlock(&n
->dev
.mutex
);
1057 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
1060 struct vhost_net
*n
= f
->private_data
;
1061 void __user
*argp
= (void __user
*)arg
;
1062 u64 __user
*featurep
= argp
;
1063 struct vhost_vring_file backend
;
1068 case VHOST_NET_SET_BACKEND
:
1069 if (copy_from_user(&backend
, argp
, sizeof backend
))
1071 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
1072 case VHOST_GET_FEATURES
:
1073 features
= VHOST_NET_FEATURES
;
1074 if (copy_to_user(featurep
, &features
, sizeof features
))
1077 case VHOST_SET_FEATURES
:
1078 if (copy_from_user(&features
, featurep
, sizeof features
))
1080 if (features
& ~VHOST_NET_FEATURES
)
1082 return vhost_net_set_features(n
, features
);
1083 case VHOST_RESET_OWNER
:
1084 return vhost_net_reset_owner(n
);
1085 case VHOST_SET_OWNER
:
1086 return vhost_net_set_owner(n
);
1088 mutex_lock(&n
->dev
.mutex
);
1089 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, argp
);
1090 if (r
== -ENOIOCTLCMD
)
1091 r
= vhost_vring_ioctl(&n
->dev
, ioctl
, argp
);
1094 mutex_unlock(&n
->dev
.mutex
);
1099 #ifdef CONFIG_COMPAT
1100 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
1103 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
1107 static const struct file_operations vhost_net_fops
= {
1108 .owner
= THIS_MODULE
,
1109 .release
= vhost_net_release
,
1110 .unlocked_ioctl
= vhost_net_ioctl
,
1111 #ifdef CONFIG_COMPAT
1112 .compat_ioctl
= vhost_net_compat_ioctl
,
1114 .open
= vhost_net_open
,
1115 .llseek
= noop_llseek
,
1118 static struct miscdevice vhost_net_misc
= {
1119 .minor
= VHOST_NET_MINOR
,
1120 .name
= "vhost-net",
1121 .fops
= &vhost_net_fops
,
1124 static int vhost_net_init(void)
1126 if (experimental_zcopytx
)
1127 vhost_net_enable_zcopy(VHOST_NET_VQ_TX
);
1128 return misc_register(&vhost_net_misc
);
1130 module_init(vhost_net_init
);
1132 static void vhost_net_exit(void)
1134 misc_deregister(&vhost_net_misc
);
1136 module_exit(vhost_net_exit
);
1138 MODULE_VERSION("0.0.1");
1139 MODULE_LICENSE("GPL v2");
1140 MODULE_AUTHOR("Michael S. Tsirkin");
1141 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1142 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
1143 MODULE_ALIAS("devname:vhost-net");