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/sched/clock.h>
21 #include <linux/sched/signal.h>
22 #include <linux/vmalloc.h>
24 #include <linux/net.h>
25 #include <linux/if_packet.h>
26 #include <linux/if_arp.h>
27 #include <linux/if_tun.h>
28 #include <linux/if_macvlan.h>
29 #include <linux/if_tap.h>
30 #include <linux/if_vlan.h>
31 #include <linux/skb_array.h>
32 #include <linux/skbuff.h>
39 static int experimental_zcopytx
= 1;
40 module_param(experimental_zcopytx
, int, 0444);
41 MODULE_PARM_DESC(experimental_zcopytx
, "Enable Zero Copy TX;"
42 " 1 -Enable; 0 - Disable");
44 /* Max number of bytes transferred before requeueing the job.
45 * Using this limit prevents one virtqueue from starving others. */
46 #define VHOST_NET_WEIGHT 0x80000
48 /* Max number of packets transferred before requeueing the job.
49 * Using this limit prevents one virtqueue from starving others with small
52 #define VHOST_NET_PKT_WEIGHT 256
54 /* MAX number of TX used buffers for outstanding zerocopy */
55 #define VHOST_MAX_PEND 128
56 #define VHOST_GOODCOPY_LEN 256
59 * For transmit, used buffer len is unused; we override it to track buffer
60 * status internally; used for zerocopy tx only.
62 /* Lower device DMA failed */
63 #define VHOST_DMA_FAILED_LEN ((__force __virtio32)3)
64 /* Lower device DMA done */
65 #define VHOST_DMA_DONE_LEN ((__force __virtio32)2)
66 /* Lower device DMA in progress */
67 #define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1)
69 #define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0)
71 #define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN)
74 VHOST_NET_FEATURES
= VHOST_FEATURES
|
75 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR
) |
76 (1ULL << VIRTIO_NET_F_MRG_RXBUF
) |
77 (1ULL << VIRTIO_F_IOMMU_PLATFORM
)
86 struct vhost_net_ubuf_ref
{
87 /* refcount follows semantics similar to kref:
88 * 0: object is released
89 * 1: no outstanding ubufs
90 * >1: outstanding ubufs
93 wait_queue_head_t wait
;
94 struct vhost_virtqueue
*vq
;
97 #define VHOST_RX_BATCH 64
98 struct vhost_net_buf
{
104 struct vhost_net_virtqueue
{
105 struct vhost_virtqueue vq
;
108 /* vhost zerocopy support fields below: */
109 /* last used idx for outstanding DMA zerocopy buffers */
111 /* For TX, first used idx for DMA done zerocopy buffers
112 * For RX, number of batched heads
115 /* an array of userspace buffers info */
116 struct ubuf_info
*ubuf_info
;
117 /* Reference counting for outstanding ubufs.
118 * Protected by vq mutex. Writers must also take device mutex. */
119 struct vhost_net_ubuf_ref
*ubufs
;
120 struct ptr_ring
*rx_ring
;
121 struct vhost_net_buf rxq
;
125 struct vhost_dev dev
;
126 struct vhost_net_virtqueue vqs
[VHOST_NET_VQ_MAX
];
127 struct vhost_poll poll
[VHOST_NET_VQ_MAX
];
128 /* Number of TX recently submitted.
129 * Protected by tx vq lock. */
131 /* Number of times zerocopy TX recently failed.
132 * Protected by tx vq lock. */
133 unsigned tx_zcopy_err
;
134 /* Flush in progress. Protected by tx vq lock. */
138 static unsigned vhost_net_zcopy_mask __read_mostly
;
140 static void *vhost_net_buf_get_ptr(struct vhost_net_buf
*rxq
)
142 if (rxq
->tail
!= rxq
->head
)
143 return rxq
->queue
[rxq
->head
];
148 static int vhost_net_buf_get_size(struct vhost_net_buf
*rxq
)
150 return rxq
->tail
- rxq
->head
;
153 static int vhost_net_buf_is_empty(struct vhost_net_buf
*rxq
)
155 return rxq
->tail
== rxq
->head
;
158 static void *vhost_net_buf_consume(struct vhost_net_buf
*rxq
)
160 void *ret
= vhost_net_buf_get_ptr(rxq
);
165 static int vhost_net_buf_produce(struct vhost_net_virtqueue
*nvq
)
167 struct vhost_net_buf
*rxq
= &nvq
->rxq
;
170 rxq
->tail
= ptr_ring_consume_batched(nvq
->rx_ring
, rxq
->queue
,
175 static void vhost_net_buf_unproduce(struct vhost_net_virtqueue
*nvq
)
177 struct vhost_net_buf
*rxq
= &nvq
->rxq
;
179 if (nvq
->rx_ring
&& !vhost_net_buf_is_empty(rxq
)) {
180 ptr_ring_unconsume(nvq
->rx_ring
, rxq
->queue
+ rxq
->head
,
181 vhost_net_buf_get_size(rxq
),
183 rxq
->head
= rxq
->tail
= 0;
187 static int vhost_net_buf_peek_len(void *ptr
)
189 if (tun_is_xdp_frame(ptr
)) {
190 struct xdp_frame
*xdpf
= tun_ptr_to_xdp(ptr
);
195 return __skb_array_len_with_tag(ptr
);
198 static int vhost_net_buf_peek(struct vhost_net_virtqueue
*nvq
)
200 struct vhost_net_buf
*rxq
= &nvq
->rxq
;
202 if (!vhost_net_buf_is_empty(rxq
))
205 if (!vhost_net_buf_produce(nvq
))
209 return vhost_net_buf_peek_len(vhost_net_buf_get_ptr(rxq
));
212 static void vhost_net_buf_init(struct vhost_net_buf
*rxq
)
214 rxq
->head
= rxq
->tail
= 0;
217 static void vhost_net_enable_zcopy(int vq
)
219 vhost_net_zcopy_mask
|= 0x1 << vq
;
222 static struct vhost_net_ubuf_ref
*
223 vhost_net_ubuf_alloc(struct vhost_virtqueue
*vq
, bool zcopy
)
225 struct vhost_net_ubuf_ref
*ubufs
;
226 /* No zero copy backend? Nothing to count. */
229 ubufs
= kmalloc(sizeof(*ubufs
), GFP_KERNEL
);
231 return ERR_PTR(-ENOMEM
);
232 atomic_set(&ubufs
->refcount
, 1);
233 init_waitqueue_head(&ubufs
->wait
);
238 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref
*ubufs
)
240 int r
= atomic_sub_return(1, &ubufs
->refcount
);
242 wake_up(&ubufs
->wait
);
246 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref
*ubufs
)
248 vhost_net_ubuf_put(ubufs
);
249 wait_event(ubufs
->wait
, !atomic_read(&ubufs
->refcount
));
252 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref
*ubufs
)
254 vhost_net_ubuf_put_and_wait(ubufs
);
258 static void vhost_net_clear_ubuf_info(struct vhost_net
*n
)
262 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
263 kfree(n
->vqs
[i
].ubuf_info
);
264 n
->vqs
[i
].ubuf_info
= NULL
;
268 static int vhost_net_set_ubuf_info(struct vhost_net
*n
)
273 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
274 zcopy
= vhost_net_zcopy_mask
& (0x1 << i
);
277 n
->vqs
[i
].ubuf_info
=
278 kmalloc_array(UIO_MAXIOV
,
279 sizeof(*n
->vqs
[i
].ubuf_info
),
281 if (!n
->vqs
[i
].ubuf_info
)
287 vhost_net_clear_ubuf_info(n
);
291 static void vhost_net_vq_reset(struct vhost_net
*n
)
295 vhost_net_clear_ubuf_info(n
);
297 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
298 n
->vqs
[i
].done_idx
= 0;
299 n
->vqs
[i
].upend_idx
= 0;
300 n
->vqs
[i
].ubufs
= NULL
;
301 n
->vqs
[i
].vhost_hlen
= 0;
302 n
->vqs
[i
].sock_hlen
= 0;
303 vhost_net_buf_init(&n
->vqs
[i
].rxq
);
308 static void vhost_net_tx_packet(struct vhost_net
*net
)
311 if (net
->tx_packets
< 1024)
314 net
->tx_zcopy_err
= 0;
317 static void vhost_net_tx_err(struct vhost_net
*net
)
322 static bool vhost_net_tx_select_zcopy(struct vhost_net
*net
)
324 /* TX flush waits for outstanding DMAs to be done.
325 * Don't start new DMAs.
327 return !net
->tx_flush
&&
328 net
->tx_packets
/ 64 >= net
->tx_zcopy_err
;
331 static bool vhost_sock_zcopy(struct socket
*sock
)
333 return unlikely(experimental_zcopytx
) &&
334 sock_flag(sock
->sk
, SOCK_ZEROCOPY
);
337 /* In case of DMA done not in order in lower device driver for some reason.
338 * upend_idx is used to track end of used idx, done_idx is used to track head
339 * of used idx. Once lower device DMA done contiguously, we will signal KVM
342 static void vhost_zerocopy_signal_used(struct vhost_net
*net
,
343 struct vhost_virtqueue
*vq
)
345 struct vhost_net_virtqueue
*nvq
=
346 container_of(vq
, struct vhost_net_virtqueue
, vq
);
350 for (i
= nvq
->done_idx
; i
!= nvq
->upend_idx
; i
= (i
+ 1) % UIO_MAXIOV
) {
351 if (vq
->heads
[i
].len
== VHOST_DMA_FAILED_LEN
)
352 vhost_net_tx_err(net
);
353 if (VHOST_DMA_IS_DONE(vq
->heads
[i
].len
)) {
354 vq
->heads
[i
].len
= VHOST_DMA_CLEAR_LEN
;
360 add
= min(UIO_MAXIOV
- nvq
->done_idx
, j
);
361 vhost_add_used_and_signal_n(vq
->dev
, vq
,
362 &vq
->heads
[nvq
->done_idx
], add
);
363 nvq
->done_idx
= (nvq
->done_idx
+ add
) % UIO_MAXIOV
;
368 static void vhost_zerocopy_callback(struct ubuf_info
*ubuf
, bool success
)
370 struct vhost_net_ubuf_ref
*ubufs
= ubuf
->ctx
;
371 struct vhost_virtqueue
*vq
= ubufs
->vq
;
376 /* set len to mark this desc buffers done DMA */
377 vq
->heads
[ubuf
->desc
].len
= success
?
378 VHOST_DMA_DONE_LEN
: VHOST_DMA_FAILED_LEN
;
379 cnt
= vhost_net_ubuf_put(ubufs
);
382 * Trigger polling thread if guest stopped submitting new buffers:
383 * in this case, the refcount after decrement will eventually reach 1.
384 * We also trigger polling periodically after each 16 packets
385 * (the value 16 here is more or less arbitrary, it's tuned to trigger
386 * less than 10% of times).
388 if (cnt
<= 1 || !(cnt
% 16))
389 vhost_poll_queue(&vq
->poll
);
391 rcu_read_unlock_bh();
394 static inline unsigned long busy_clock(void)
396 return local_clock() >> 10;
399 static bool vhost_can_busy_poll(struct vhost_dev
*dev
,
400 unsigned long endtime
)
402 return likely(!need_resched()) &&
403 likely(!time_after(busy_clock(), endtime
)) &&
404 likely(!signal_pending(current
)) &&
405 !vhost_has_work(dev
);
408 static void vhost_net_disable_vq(struct vhost_net
*n
,
409 struct vhost_virtqueue
*vq
)
411 struct vhost_net_virtqueue
*nvq
=
412 container_of(vq
, struct vhost_net_virtqueue
, vq
);
413 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
414 if (!vq
->private_data
)
416 vhost_poll_stop(poll
);
419 static int vhost_net_enable_vq(struct vhost_net
*n
,
420 struct vhost_virtqueue
*vq
)
422 struct vhost_net_virtqueue
*nvq
=
423 container_of(vq
, struct vhost_net_virtqueue
, vq
);
424 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
427 sock
= vq
->private_data
;
431 return vhost_poll_start(poll
, sock
->file
);
434 static int vhost_net_tx_get_vq_desc(struct vhost_net
*net
,
435 struct vhost_virtqueue
*vq
,
436 struct iovec iov
[], unsigned int iov_size
,
437 unsigned int *out_num
, unsigned int *in_num
)
439 unsigned long uninitialized_var(endtime
);
440 int r
= vhost_get_vq_desc(vq
, vq
->iov
, ARRAY_SIZE(vq
->iov
),
441 out_num
, in_num
, NULL
, NULL
);
443 if (r
== vq
->num
&& vq
->busyloop_timeout
) {
445 endtime
= busy_clock() + vq
->busyloop_timeout
;
446 while (vhost_can_busy_poll(vq
->dev
, endtime
) &&
447 vhost_vq_avail_empty(vq
->dev
, vq
))
450 r
= vhost_get_vq_desc(vq
, vq
->iov
, ARRAY_SIZE(vq
->iov
),
451 out_num
, in_num
, NULL
, NULL
);
457 static bool vhost_exceeds_maxpend(struct vhost_net
*net
)
459 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
460 struct vhost_virtqueue
*vq
= &nvq
->vq
;
462 return (nvq
->upend_idx
+ UIO_MAXIOV
- nvq
->done_idx
) % UIO_MAXIOV
>
463 min_t(unsigned int, VHOST_MAX_PEND
, vq
->num
>> 2);
466 /* Expects to be always run from workqueue - which acts as
467 * read-size critical section for our kind of RCU. */
468 static void handle_tx(struct vhost_net
*net
)
470 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
471 struct vhost_virtqueue
*vq
= &nvq
->vq
;
474 struct msghdr msg
= {
479 .msg_flags
= MSG_DONTWAIT
,
481 size_t len
, total_len
= 0;
485 struct vhost_net_ubuf_ref
*uninitialized_var(ubufs
);
486 bool zcopy
, zcopy_used
;
489 mutex_lock(&vq
->mutex
);
490 sock
= vq
->private_data
;
494 if (!vq_iotlb_prefetch(vq
))
497 vhost_disable_notify(&net
->dev
, vq
);
498 vhost_net_disable_vq(net
, vq
);
500 hdr_size
= nvq
->vhost_hlen
;
504 /* Release DMAs done buffers first */
506 vhost_zerocopy_signal_used(net
, vq
);
509 head
= vhost_net_tx_get_vq_desc(net
, vq
, vq
->iov
,
512 /* On error, stop handling until the next kick. */
513 if (unlikely(head
< 0))
515 /* Nothing new? Wait for eventfd to tell us they refilled. */
516 if (head
== vq
->num
) {
517 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
518 vhost_disable_notify(&net
->dev
, vq
);
524 vq_err(vq
, "Unexpected descriptor format for TX: "
525 "out %d, int %d\n", out
, in
);
528 /* Skip header. TODO: support TSO. */
529 len
= iov_length(vq
->iov
, out
);
530 iov_iter_init(&msg
.msg_iter
, WRITE
, vq
->iov
, out
, len
);
531 iov_iter_advance(&msg
.msg_iter
, hdr_size
);
533 if (!msg_data_left(&msg
)) {
534 vq_err(vq
, "Unexpected header len for TX: "
535 "%zd expected %zd\n",
539 len
= msg_data_left(&msg
);
541 zcopy_used
= zcopy
&& len
>= VHOST_GOODCOPY_LEN
542 && !vhost_exceeds_maxpend(net
)
543 && vhost_net_tx_select_zcopy(net
);
545 /* use msg_control to pass vhost zerocopy ubuf info to skb */
547 struct ubuf_info
*ubuf
;
548 ubuf
= nvq
->ubuf_info
+ nvq
->upend_idx
;
550 vq
->heads
[nvq
->upend_idx
].id
= cpu_to_vhost32(vq
, head
);
551 vq
->heads
[nvq
->upend_idx
].len
= VHOST_DMA_IN_PROGRESS
;
552 ubuf
->callback
= vhost_zerocopy_callback
;
553 ubuf
->ctx
= nvq
->ubufs
;
554 ubuf
->desc
= nvq
->upend_idx
;
555 refcount_set(&ubuf
->refcnt
, 1);
556 msg
.msg_control
= ubuf
;
557 msg
.msg_controllen
= sizeof(ubuf
);
559 atomic_inc(&ubufs
->refcount
);
560 nvq
->upend_idx
= (nvq
->upend_idx
+ 1) % UIO_MAXIOV
;
562 msg
.msg_control
= NULL
;
567 if (total_len
< VHOST_NET_WEIGHT
&&
568 !vhost_vq_avail_empty(&net
->dev
, vq
) &&
569 likely(!vhost_exceeds_maxpend(net
))) {
570 msg
.msg_flags
|= MSG_MORE
;
572 msg
.msg_flags
&= ~MSG_MORE
;
575 /* TODO: Check specific error and bomb out unless ENOBUFS? */
576 err
= sock
->ops
->sendmsg(sock
, &msg
, len
);
577 if (unlikely(err
< 0)) {
579 vhost_net_ubuf_put(ubufs
);
580 nvq
->upend_idx
= ((unsigned)nvq
->upend_idx
- 1)
583 vhost_discard_vq_desc(vq
, 1);
584 vhost_net_enable_vq(net
, vq
);
588 pr_debug("Truncated TX packet: "
589 " len %d != %zd\n", err
, len
);
591 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
593 vhost_zerocopy_signal_used(net
, vq
);
594 vhost_net_tx_packet(net
);
595 if (unlikely(total_len
>= VHOST_NET_WEIGHT
) ||
596 unlikely(++sent_pkts
>= VHOST_NET_PKT_WEIGHT
)) {
597 vhost_poll_queue(&vq
->poll
);
602 mutex_unlock(&vq
->mutex
);
605 static int peek_head_len(struct vhost_net_virtqueue
*rvq
, struct sock
*sk
)
607 struct sk_buff
*head
;
612 return vhost_net_buf_peek(rvq
);
614 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
615 head
= skb_peek(&sk
->sk_receive_queue
);
618 if (skb_vlan_tag_present(head
))
622 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
626 static int sk_has_rx_data(struct sock
*sk
)
628 struct socket
*sock
= sk
->sk_socket
;
630 if (sock
->ops
->peek_len
)
631 return sock
->ops
->peek_len(sock
);
633 return skb_queue_empty(&sk
->sk_receive_queue
);
636 static void vhost_rx_signal_used(struct vhost_net_virtqueue
*nvq
)
638 struct vhost_virtqueue
*vq
= &nvq
->vq
;
639 struct vhost_dev
*dev
= vq
->dev
;
644 vhost_add_used_and_signal_n(dev
, vq
, vq
->heads
, nvq
->done_idx
);
648 static int vhost_net_rx_peek_head_len(struct vhost_net
*net
, struct sock
*sk
)
650 struct vhost_net_virtqueue
*rvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
651 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
652 struct vhost_virtqueue
*vq
= &nvq
->vq
;
653 unsigned long uninitialized_var(endtime
);
654 int len
= peek_head_len(rvq
, sk
);
656 if (!len
&& vq
->busyloop_timeout
) {
657 /* Flush batched heads first */
658 vhost_rx_signal_used(rvq
);
659 /* Both tx vq and rx socket were polled here */
660 mutex_lock_nested(&vq
->mutex
, 1);
661 vhost_disable_notify(&net
->dev
, vq
);
664 endtime
= busy_clock() + vq
->busyloop_timeout
;
666 while (vhost_can_busy_poll(&net
->dev
, endtime
) &&
667 !sk_has_rx_data(sk
) &&
668 vhost_vq_avail_empty(&net
->dev
, vq
))
673 if (!vhost_vq_avail_empty(&net
->dev
, vq
))
674 vhost_poll_queue(&vq
->poll
);
675 else if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
676 vhost_disable_notify(&net
->dev
, vq
);
677 vhost_poll_queue(&vq
->poll
);
680 mutex_unlock(&vq
->mutex
);
682 len
= peek_head_len(rvq
, sk
);
688 /* This is a multi-buffer version of vhost_get_desc, that works if
689 * vq has read descriptors only.
690 * @vq - the relevant virtqueue
691 * @datalen - data length we'll be reading
692 * @iovcount - returned count of io vectors we fill
694 * @log_num - log offset
695 * @quota - headcount quota, 1 for big buffer
696 * returns number of buffer heads allocated, negative on error
698 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
699 struct vring_used_elem
*heads
,
702 struct vhost_log
*log
,
706 unsigned int out
, in
;
711 /* len is always initialized before use since we are always called with
714 u32
uninitialized_var(len
);
716 while (datalen
> 0 && headcount
< quota
) {
717 if (unlikely(seg
>= UIO_MAXIOV
)) {
721 r
= vhost_get_vq_desc(vq
, vq
->iov
+ seg
,
722 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
732 if (unlikely(out
|| in
<= 0)) {
733 vq_err(vq
, "unexpected descriptor format for RX: "
734 "out %d, in %d\n", out
, in
);
742 heads
[headcount
].id
= cpu_to_vhost32(vq
, d
);
743 len
= iov_length(vq
->iov
+ seg
, in
);
744 heads
[headcount
].len
= cpu_to_vhost32(vq
, len
);
749 heads
[headcount
- 1].len
= cpu_to_vhost32(vq
, len
+ datalen
);
755 if (unlikely(datalen
> 0)) {
761 vhost_discard_vq_desc(vq
, headcount
);
765 /* Expects to be always run from workqueue - which acts as
766 * read-size critical section for our kind of RCU. */
767 static void handle_rx(struct vhost_net
*net
)
769 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
770 struct vhost_virtqueue
*vq
= &nvq
->vq
;
771 unsigned uninitialized_var(in
), log
;
772 struct vhost_log
*vq_log
;
773 struct msghdr msg
= {
776 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
778 .msg_flags
= MSG_DONTWAIT
,
780 struct virtio_net_hdr hdr
= {
782 .gso_type
= VIRTIO_NET_HDR_GSO_NONE
784 size_t total_len
= 0;
787 size_t vhost_hlen
, sock_hlen
;
788 size_t vhost_len
, sock_len
;
790 struct iov_iter fixup
;
791 __virtio16 num_buffers
;
794 mutex_lock_nested(&vq
->mutex
, 0);
795 sock
= vq
->private_data
;
799 if (!vq_iotlb_prefetch(vq
))
802 vhost_disable_notify(&net
->dev
, vq
);
803 vhost_net_disable_vq(net
, vq
);
805 vhost_hlen
= nvq
->vhost_hlen
;
806 sock_hlen
= nvq
->sock_hlen
;
808 vq_log
= unlikely(vhost_has_feature(vq
, VHOST_F_LOG_ALL
)) ?
810 mergeable
= vhost_has_feature(vq
, VIRTIO_NET_F_MRG_RXBUF
);
812 while ((sock_len
= vhost_net_rx_peek_head_len(net
, sock
->sk
))) {
813 sock_len
+= sock_hlen
;
814 vhost_len
= sock_len
+ vhost_hlen
;
815 headcount
= get_rx_bufs(vq
, vq
->heads
+ nvq
->done_idx
,
816 vhost_len
, &in
, vq_log
, &log
,
817 likely(mergeable
) ? UIO_MAXIOV
: 1);
818 /* On error, stop handling until the next kick. */
819 if (unlikely(headcount
< 0))
821 /* OK, now we need to know about added descriptors. */
823 if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
824 /* They have slipped one in as we were
825 * doing that: check again. */
826 vhost_disable_notify(&net
->dev
, vq
);
829 /* Nothing new? Wait for eventfd to tell us
834 msg
.msg_control
= vhost_net_buf_consume(&nvq
->rxq
);
835 /* On overrun, truncate and discard */
836 if (unlikely(headcount
> UIO_MAXIOV
)) {
837 iov_iter_init(&msg
.msg_iter
, READ
, vq
->iov
, 1, 1);
838 err
= sock
->ops
->recvmsg(sock
, &msg
,
839 1, MSG_DONTWAIT
| MSG_TRUNC
);
840 pr_debug("Discarded rx packet: len %zd\n", sock_len
);
843 /* We don't need to be notified again. */
844 iov_iter_init(&msg
.msg_iter
, READ
, vq
->iov
, in
, vhost_len
);
845 fixup
= msg
.msg_iter
;
846 if (unlikely((vhost_hlen
))) {
847 /* We will supply the header ourselves
850 iov_iter_advance(&msg
.msg_iter
, vhost_hlen
);
852 err
= sock
->ops
->recvmsg(sock
, &msg
,
853 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
854 /* Userspace might have consumed the packet meanwhile:
855 * it's not supposed to do this usually, but might be hard
856 * to prevent. Discard data we got (if any) and keep going. */
857 if (unlikely(err
!= sock_len
)) {
858 pr_debug("Discarded rx packet: "
859 " len %d, expected %zd\n", err
, sock_len
);
860 vhost_discard_vq_desc(vq
, headcount
);
863 /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
864 if (unlikely(vhost_hlen
)) {
865 if (copy_to_iter(&hdr
, sizeof(hdr
),
866 &fixup
) != sizeof(hdr
)) {
867 vq_err(vq
, "Unable to write vnet_hdr "
868 "at addr %p\n", vq
->iov
->iov_base
);
872 /* Header came from socket; we'll need to patch
873 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF
875 iov_iter_advance(&fixup
, sizeof(hdr
));
877 /* TODO: Should check and handle checksum. */
879 num_buffers
= cpu_to_vhost16(vq
, headcount
);
880 if (likely(mergeable
) &&
881 copy_to_iter(&num_buffers
, sizeof num_buffers
,
882 &fixup
) != sizeof num_buffers
) {
883 vq_err(vq
, "Failed num_buffers write");
884 vhost_discard_vq_desc(vq
, headcount
);
887 nvq
->done_idx
+= headcount
;
888 if (nvq
->done_idx
> VHOST_RX_BATCH
)
889 vhost_rx_signal_used(nvq
);
890 if (unlikely(vq_log
))
891 vhost_log_write(vq
, vq_log
, log
, vhost_len
);
892 total_len
+= vhost_len
;
893 if (unlikely(total_len
>= VHOST_NET_WEIGHT
) ||
894 unlikely(++recv_pkts
>= VHOST_NET_PKT_WEIGHT
)) {
895 vhost_poll_queue(&vq
->poll
);
899 vhost_net_enable_vq(net
, vq
);
901 vhost_rx_signal_used(nvq
);
902 mutex_unlock(&vq
->mutex
);
905 static void handle_tx_kick(struct vhost_work
*work
)
907 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
909 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
914 static void handle_rx_kick(struct vhost_work
*work
)
916 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
918 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
923 static void handle_tx_net(struct vhost_work
*work
)
925 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
926 poll
[VHOST_NET_VQ_TX
].work
);
930 static void handle_rx_net(struct vhost_work
*work
)
932 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
933 poll
[VHOST_NET_VQ_RX
].work
);
937 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
940 struct vhost_dev
*dev
;
941 struct vhost_virtqueue
**vqs
;
945 n
= kvmalloc(sizeof *n
, GFP_KERNEL
| __GFP_RETRY_MAYFAIL
);
948 vqs
= kmalloc_array(VHOST_NET_VQ_MAX
, sizeof(*vqs
), GFP_KERNEL
);
954 queue
= kmalloc_array(VHOST_RX_BATCH
, sizeof(void *),
961 n
->vqs
[VHOST_NET_VQ_RX
].rxq
.queue
= queue
;
964 vqs
[VHOST_NET_VQ_TX
] = &n
->vqs
[VHOST_NET_VQ_TX
].vq
;
965 vqs
[VHOST_NET_VQ_RX
] = &n
->vqs
[VHOST_NET_VQ_RX
].vq
;
966 n
->vqs
[VHOST_NET_VQ_TX
].vq
.handle_kick
= handle_tx_kick
;
967 n
->vqs
[VHOST_NET_VQ_RX
].vq
.handle_kick
= handle_rx_kick
;
968 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
969 n
->vqs
[i
].ubufs
= NULL
;
970 n
->vqs
[i
].ubuf_info
= NULL
;
971 n
->vqs
[i
].upend_idx
= 0;
972 n
->vqs
[i
].done_idx
= 0;
973 n
->vqs
[i
].vhost_hlen
= 0;
974 n
->vqs
[i
].sock_hlen
= 0;
975 n
->vqs
[i
].rx_ring
= NULL
;
976 vhost_net_buf_init(&n
->vqs
[i
].rxq
);
978 vhost_dev_init(dev
, vqs
, VHOST_NET_VQ_MAX
);
980 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, EPOLLOUT
, dev
);
981 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, EPOLLIN
, dev
);
988 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
989 struct vhost_virtqueue
*vq
)
992 struct vhost_net_virtqueue
*nvq
=
993 container_of(vq
, struct vhost_net_virtqueue
, vq
);
995 mutex_lock(&vq
->mutex
);
996 sock
= vq
->private_data
;
997 vhost_net_disable_vq(n
, vq
);
998 vq
->private_data
= NULL
;
999 vhost_net_buf_unproduce(nvq
);
1000 nvq
->rx_ring
= NULL
;
1001 mutex_unlock(&vq
->mutex
);
1005 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
1006 struct socket
**rx_sock
)
1008 *tx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_TX
].vq
);
1009 *rx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_RX
].vq
);
1012 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
1014 vhost_poll_flush(n
->poll
+ index
);
1015 vhost_poll_flush(&n
->vqs
[index
].vq
.poll
);
1018 static void vhost_net_flush(struct vhost_net
*n
)
1020 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
1021 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
1022 if (n
->vqs
[VHOST_NET_VQ_TX
].ubufs
) {
1023 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1025 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1026 /* Wait for all lower device DMAs done. */
1027 vhost_net_ubuf_put_and_wait(n
->vqs
[VHOST_NET_VQ_TX
].ubufs
);
1028 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1029 n
->tx_flush
= false;
1030 atomic_set(&n
->vqs
[VHOST_NET_VQ_TX
].ubufs
->refcount
, 1);
1031 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1035 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
1037 struct vhost_net
*n
= f
->private_data
;
1038 struct socket
*tx_sock
;
1039 struct socket
*rx_sock
;
1041 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
1043 vhost_dev_stop(&n
->dev
);
1044 vhost_dev_cleanup(&n
->dev
);
1045 vhost_net_vq_reset(n
);
1047 sockfd_put(tx_sock
);
1049 sockfd_put(rx_sock
);
1050 /* Make sure no callbacks are outstanding */
1051 synchronize_rcu_bh();
1052 /* We do an extra flush before freeing memory,
1053 * since jobs can re-queue themselves. */
1055 kfree(n
->vqs
[VHOST_NET_VQ_RX
].rxq
.queue
);
1061 static struct socket
*get_raw_socket(int fd
)
1064 struct sockaddr_ll sa
;
1065 char buf
[MAX_ADDR_LEN
];
1068 struct socket
*sock
= sockfd_lookup(fd
, &r
);
1071 return ERR_PTR(-ENOTSOCK
);
1073 /* Parameter checking */
1074 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
1075 r
= -ESOCKTNOSUPPORT
;
1079 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
, 0);
1083 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
1093 static struct ptr_ring
*get_tap_ptr_ring(int fd
)
1095 struct ptr_ring
*ring
;
1096 struct file
*file
= fget(fd
);
1100 ring
= tun_get_tx_ring(file
);
1103 ring
= tap_get_ptr_ring(file
);
1112 static struct socket
*get_tap_socket(int fd
)
1114 struct file
*file
= fget(fd
);
1115 struct socket
*sock
;
1118 return ERR_PTR(-EBADF
);
1119 sock
= tun_get_socket(file
);
1122 sock
= tap_get_socket(file
);
1128 static struct socket
*get_socket(int fd
)
1130 struct socket
*sock
;
1132 /* special case to disable backend */
1135 sock
= get_raw_socket(fd
);
1138 sock
= get_tap_socket(fd
);
1141 return ERR_PTR(-ENOTSOCK
);
1144 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
1146 struct socket
*sock
, *oldsock
;
1147 struct vhost_virtqueue
*vq
;
1148 struct vhost_net_virtqueue
*nvq
;
1149 struct vhost_net_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
1152 mutex_lock(&n
->dev
.mutex
);
1153 r
= vhost_dev_check_owner(&n
->dev
);
1157 if (index
>= VHOST_NET_VQ_MAX
) {
1161 vq
= &n
->vqs
[index
].vq
;
1162 nvq
= &n
->vqs
[index
];
1163 mutex_lock(&vq
->mutex
);
1165 /* Verify that ring has been setup correctly. */
1166 if (!vhost_vq_access_ok(vq
)) {
1170 sock
= get_socket(fd
);
1176 /* start polling new socket */
1177 oldsock
= vq
->private_data
;
1178 if (sock
!= oldsock
) {
1179 ubufs
= vhost_net_ubuf_alloc(vq
,
1180 sock
&& vhost_sock_zcopy(sock
));
1181 if (IS_ERR(ubufs
)) {
1186 vhost_net_disable_vq(n
, vq
);
1187 vq
->private_data
= sock
;
1188 vhost_net_buf_unproduce(nvq
);
1189 r
= vhost_vq_init_access(vq
);
1192 r
= vhost_net_enable_vq(n
, vq
);
1195 if (index
== VHOST_NET_VQ_RX
)
1196 nvq
->rx_ring
= get_tap_ptr_ring(fd
);
1198 oldubufs
= nvq
->ubufs
;
1202 n
->tx_zcopy_err
= 0;
1203 n
->tx_flush
= false;
1206 mutex_unlock(&vq
->mutex
);
1209 vhost_net_ubuf_put_wait_and_free(oldubufs
);
1210 mutex_lock(&vq
->mutex
);
1211 vhost_zerocopy_signal_used(n
, vq
);
1212 mutex_unlock(&vq
->mutex
);
1216 vhost_net_flush_vq(n
, index
);
1217 sockfd_put(oldsock
);
1220 mutex_unlock(&n
->dev
.mutex
);
1224 vq
->private_data
= oldsock
;
1225 vhost_net_enable_vq(n
, vq
);
1227 vhost_net_ubuf_put_wait_and_free(ubufs
);
1231 mutex_unlock(&vq
->mutex
);
1233 mutex_unlock(&n
->dev
.mutex
);
1237 static long vhost_net_reset_owner(struct vhost_net
*n
)
1239 struct socket
*tx_sock
= NULL
;
1240 struct socket
*rx_sock
= NULL
;
1242 struct vhost_umem
*umem
;
1244 mutex_lock(&n
->dev
.mutex
);
1245 err
= vhost_dev_check_owner(&n
->dev
);
1248 umem
= vhost_dev_reset_owner_prepare();
1253 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
1255 vhost_dev_stop(&n
->dev
);
1256 vhost_dev_reset_owner(&n
->dev
, umem
);
1257 vhost_net_vq_reset(n
);
1259 mutex_unlock(&n
->dev
.mutex
);
1261 sockfd_put(tx_sock
);
1263 sockfd_put(rx_sock
);
1267 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
1269 size_t vhost_hlen
, sock_hlen
, hdr_len
;
1272 hdr_len
= (features
& ((1ULL << VIRTIO_NET_F_MRG_RXBUF
) |
1273 (1ULL << VIRTIO_F_VERSION_1
))) ?
1274 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
1275 sizeof(struct virtio_net_hdr
);
1276 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
1277 /* vhost provides vnet_hdr */
1278 vhost_hlen
= hdr_len
;
1281 /* socket provides vnet_hdr */
1283 sock_hlen
= hdr_len
;
1285 mutex_lock(&n
->dev
.mutex
);
1286 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
1287 !vhost_log_access_ok(&n
->dev
))
1290 if ((features
& (1ULL << VIRTIO_F_IOMMU_PLATFORM
))) {
1291 if (vhost_init_device_iotlb(&n
->dev
, true))
1295 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
1296 mutex_lock(&n
->vqs
[i
].vq
.mutex
);
1297 n
->vqs
[i
].vq
.acked_features
= features
;
1298 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
1299 n
->vqs
[i
].sock_hlen
= sock_hlen
;
1300 mutex_unlock(&n
->vqs
[i
].vq
.mutex
);
1302 mutex_unlock(&n
->dev
.mutex
);
1306 mutex_unlock(&n
->dev
.mutex
);
1310 static long vhost_net_set_owner(struct vhost_net
*n
)
1314 mutex_lock(&n
->dev
.mutex
);
1315 if (vhost_dev_has_owner(&n
->dev
)) {
1319 r
= vhost_net_set_ubuf_info(n
);
1322 r
= vhost_dev_set_owner(&n
->dev
);
1324 vhost_net_clear_ubuf_info(n
);
1327 mutex_unlock(&n
->dev
.mutex
);
1331 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
1334 struct vhost_net
*n
= f
->private_data
;
1335 void __user
*argp
= (void __user
*)arg
;
1336 u64 __user
*featurep
= argp
;
1337 struct vhost_vring_file backend
;
1342 case VHOST_NET_SET_BACKEND
:
1343 if (copy_from_user(&backend
, argp
, sizeof backend
))
1345 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
1346 case VHOST_GET_FEATURES
:
1347 features
= VHOST_NET_FEATURES
;
1348 if (copy_to_user(featurep
, &features
, sizeof features
))
1351 case VHOST_SET_FEATURES
:
1352 if (copy_from_user(&features
, featurep
, sizeof features
))
1354 if (features
& ~VHOST_NET_FEATURES
)
1356 return vhost_net_set_features(n
, features
);
1357 case VHOST_RESET_OWNER
:
1358 return vhost_net_reset_owner(n
);
1359 case VHOST_SET_OWNER
:
1360 return vhost_net_set_owner(n
);
1362 mutex_lock(&n
->dev
.mutex
);
1363 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, argp
);
1364 if (r
== -ENOIOCTLCMD
)
1365 r
= vhost_vring_ioctl(&n
->dev
, ioctl
, argp
);
1368 mutex_unlock(&n
->dev
.mutex
);
1373 #ifdef CONFIG_COMPAT
1374 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
1377 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
1381 static ssize_t
vhost_net_chr_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
1383 struct file
*file
= iocb
->ki_filp
;
1384 struct vhost_net
*n
= file
->private_data
;
1385 struct vhost_dev
*dev
= &n
->dev
;
1386 int noblock
= file
->f_flags
& O_NONBLOCK
;
1388 return vhost_chr_read_iter(dev
, to
, noblock
);
1391 static ssize_t
vhost_net_chr_write_iter(struct kiocb
*iocb
,
1392 struct iov_iter
*from
)
1394 struct file
*file
= iocb
->ki_filp
;
1395 struct vhost_net
*n
= file
->private_data
;
1396 struct vhost_dev
*dev
= &n
->dev
;
1398 return vhost_chr_write_iter(dev
, from
);
1401 static __poll_t
vhost_net_chr_poll(struct file
*file
, poll_table
*wait
)
1403 struct vhost_net
*n
= file
->private_data
;
1404 struct vhost_dev
*dev
= &n
->dev
;
1406 return vhost_chr_poll(file
, dev
, wait
);
1409 static const struct file_operations vhost_net_fops
= {
1410 .owner
= THIS_MODULE
,
1411 .release
= vhost_net_release
,
1412 .read_iter
= vhost_net_chr_read_iter
,
1413 .write_iter
= vhost_net_chr_write_iter
,
1414 .poll
= vhost_net_chr_poll
,
1415 .unlocked_ioctl
= vhost_net_ioctl
,
1416 #ifdef CONFIG_COMPAT
1417 .compat_ioctl
= vhost_net_compat_ioctl
,
1419 .open
= vhost_net_open
,
1420 .llseek
= noop_llseek
,
1423 static struct miscdevice vhost_net_misc
= {
1424 .minor
= VHOST_NET_MINOR
,
1425 .name
= "vhost-net",
1426 .fops
= &vhost_net_fops
,
1429 static int vhost_net_init(void)
1431 if (experimental_zcopytx
)
1432 vhost_net_enable_zcopy(VHOST_NET_VQ_TX
);
1433 return misc_register(&vhost_net_misc
);
1435 module_init(vhost_net_init
);
1437 static void vhost_net_exit(void)
1439 misc_deregister(&vhost_net_misc
);
1441 module_exit(vhost_net_exit
);
1443 MODULE_VERSION("0.0.1");
1444 MODULE_LICENSE("GPL v2");
1445 MODULE_AUTHOR("Michael S. Tsirkin");
1446 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1447 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
1448 MODULE_ALIAS("devname:vhost-net");