1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (C) 2009 Red Hat, Inc.
3 * Author: Michael S. Tsirkin <mst@redhat.com>
5 * virtio-net server in host kernel.
8 #include <linux/compat.h>
9 #include <linux/eventfd.h>
10 #include <linux/vhost.h>
11 #include <linux/virtio_net.h>
12 #include <linux/miscdevice.h>
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/mutex.h>
16 #include <linux/workqueue.h>
17 #include <linux/file.h>
18 #include <linux/slab.h>
19 #include <linux/sched/clock.h>
20 #include <linux/sched/signal.h>
21 #include <linux/vmalloc.h>
23 #include <linux/net.h>
24 #include <linux/if_packet.h>
25 #include <linux/if_arp.h>
26 #include <linux/if_tun.h>
27 #include <linux/if_macvlan.h>
28 #include <linux/if_tap.h>
29 #include <linux/if_vlan.h>
30 #include <linux/skb_array.h>
31 #include <linux/skbuff.h>
38 static int experimental_zcopytx
= 0;
39 module_param(experimental_zcopytx
, int, 0444);
40 MODULE_PARM_DESC(experimental_zcopytx
, "Enable Zero Copy TX;"
41 " 1 -Enable; 0 - Disable");
43 /* Max number of bytes transferred before requeueing the job.
44 * Using this limit prevents one virtqueue from starving others. */
45 #define VHOST_NET_WEIGHT 0x80000
47 /* Max number of packets transferred before requeueing the job.
48 * Using this limit prevents one virtqueue from starving others with small
51 #define VHOST_NET_PKT_WEIGHT 256
53 /* MAX number of TX used buffers for outstanding zerocopy */
54 #define VHOST_MAX_PEND 128
55 #define VHOST_GOODCOPY_LEN 256
58 * For transmit, used buffer len is unused; we override it to track buffer
59 * status internally; used for zerocopy tx only.
61 /* Lower device DMA failed */
62 #define VHOST_DMA_FAILED_LEN ((__force __virtio32)3)
63 /* Lower device DMA done */
64 #define VHOST_DMA_DONE_LEN ((__force __virtio32)2)
65 /* Lower device DMA in progress */
66 #define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1)
68 #define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0)
70 #define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN)
73 VHOST_NET_FEATURES
= VHOST_FEATURES
|
74 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR
) |
75 (1ULL << VIRTIO_NET_F_MRG_RXBUF
) |
76 (1ULL << VIRTIO_F_ACCESS_PLATFORM
)
80 VHOST_NET_BACKEND_FEATURES
= (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2
)
89 struct vhost_net_ubuf_ref
{
90 /* refcount follows semantics similar to kref:
91 * 0: object is released
92 * 1: no outstanding ubufs
93 * >1: outstanding ubufs
96 wait_queue_head_t wait
;
97 struct vhost_virtqueue
*vq
;
100 #define VHOST_NET_BATCH 64
101 struct vhost_net_buf
{
107 struct vhost_net_virtqueue
{
108 struct vhost_virtqueue vq
;
111 /* vhost zerocopy support fields below: */
112 /* last used idx for outstanding DMA zerocopy buffers */
114 /* For TX, first used idx for DMA done zerocopy buffers
115 * For RX, number of batched heads
118 /* Number of XDP frames batched */
120 /* an array of userspace buffers info */
121 struct ubuf_info
*ubuf_info
;
122 /* Reference counting for outstanding ubufs.
123 * Protected by vq mutex. Writers must also take device mutex. */
124 struct vhost_net_ubuf_ref
*ubufs
;
125 struct ptr_ring
*rx_ring
;
126 struct vhost_net_buf rxq
;
127 /* Batched XDP buffs */
128 struct xdp_buff
*xdp
;
132 struct vhost_dev dev
;
133 struct vhost_net_virtqueue vqs
[VHOST_NET_VQ_MAX
];
134 struct vhost_poll poll
[VHOST_NET_VQ_MAX
];
135 /* Number of TX recently submitted.
136 * Protected by tx vq lock. */
138 /* Number of times zerocopy TX recently failed.
139 * Protected by tx vq lock. */
140 unsigned tx_zcopy_err
;
141 /* Flush in progress. Protected by tx vq lock. */
143 /* Private page frag */
144 struct page_frag page_frag
;
145 /* Refcount bias of page frag */
149 static unsigned vhost_net_zcopy_mask __read_mostly
;
151 static void *vhost_net_buf_get_ptr(struct vhost_net_buf
*rxq
)
153 if (rxq
->tail
!= rxq
->head
)
154 return rxq
->queue
[rxq
->head
];
159 static int vhost_net_buf_get_size(struct vhost_net_buf
*rxq
)
161 return rxq
->tail
- rxq
->head
;
164 static int vhost_net_buf_is_empty(struct vhost_net_buf
*rxq
)
166 return rxq
->tail
== rxq
->head
;
169 static void *vhost_net_buf_consume(struct vhost_net_buf
*rxq
)
171 void *ret
= vhost_net_buf_get_ptr(rxq
);
176 static int vhost_net_buf_produce(struct vhost_net_virtqueue
*nvq
)
178 struct vhost_net_buf
*rxq
= &nvq
->rxq
;
181 rxq
->tail
= ptr_ring_consume_batched(nvq
->rx_ring
, rxq
->queue
,
186 static void vhost_net_buf_unproduce(struct vhost_net_virtqueue
*nvq
)
188 struct vhost_net_buf
*rxq
= &nvq
->rxq
;
190 if (nvq
->rx_ring
&& !vhost_net_buf_is_empty(rxq
)) {
191 ptr_ring_unconsume(nvq
->rx_ring
, rxq
->queue
+ rxq
->head
,
192 vhost_net_buf_get_size(rxq
),
194 rxq
->head
= rxq
->tail
= 0;
198 static int vhost_net_buf_peek_len(void *ptr
)
200 if (tun_is_xdp_frame(ptr
)) {
201 struct xdp_frame
*xdpf
= tun_ptr_to_xdp(ptr
);
206 return __skb_array_len_with_tag(ptr
);
209 static int vhost_net_buf_peek(struct vhost_net_virtqueue
*nvq
)
211 struct vhost_net_buf
*rxq
= &nvq
->rxq
;
213 if (!vhost_net_buf_is_empty(rxq
))
216 if (!vhost_net_buf_produce(nvq
))
220 return vhost_net_buf_peek_len(vhost_net_buf_get_ptr(rxq
));
223 static void vhost_net_buf_init(struct vhost_net_buf
*rxq
)
225 rxq
->head
= rxq
->tail
= 0;
228 static void vhost_net_enable_zcopy(int vq
)
230 vhost_net_zcopy_mask
|= 0x1 << vq
;
233 static struct vhost_net_ubuf_ref
*
234 vhost_net_ubuf_alloc(struct vhost_virtqueue
*vq
, bool zcopy
)
236 struct vhost_net_ubuf_ref
*ubufs
;
237 /* No zero copy backend? Nothing to count. */
240 ubufs
= kmalloc(sizeof(*ubufs
), GFP_KERNEL
);
242 return ERR_PTR(-ENOMEM
);
243 atomic_set(&ubufs
->refcount
, 1);
244 init_waitqueue_head(&ubufs
->wait
);
249 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref
*ubufs
)
251 int r
= atomic_sub_return(1, &ubufs
->refcount
);
253 wake_up(&ubufs
->wait
);
257 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref
*ubufs
)
259 vhost_net_ubuf_put(ubufs
);
260 wait_event(ubufs
->wait
, !atomic_read(&ubufs
->refcount
));
263 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref
*ubufs
)
265 vhost_net_ubuf_put_and_wait(ubufs
);
269 static void vhost_net_clear_ubuf_info(struct vhost_net
*n
)
273 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
274 kfree(n
->vqs
[i
].ubuf_info
);
275 n
->vqs
[i
].ubuf_info
= NULL
;
279 static int vhost_net_set_ubuf_info(struct vhost_net
*n
)
284 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
285 zcopy
= vhost_net_zcopy_mask
& (0x1 << i
);
288 n
->vqs
[i
].ubuf_info
=
289 kmalloc_array(UIO_MAXIOV
,
290 sizeof(*n
->vqs
[i
].ubuf_info
),
292 if (!n
->vqs
[i
].ubuf_info
)
298 vhost_net_clear_ubuf_info(n
);
302 static void vhost_net_vq_reset(struct vhost_net
*n
)
306 vhost_net_clear_ubuf_info(n
);
308 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
309 n
->vqs
[i
].done_idx
= 0;
310 n
->vqs
[i
].upend_idx
= 0;
311 n
->vqs
[i
].ubufs
= NULL
;
312 n
->vqs
[i
].vhost_hlen
= 0;
313 n
->vqs
[i
].sock_hlen
= 0;
314 vhost_net_buf_init(&n
->vqs
[i
].rxq
);
319 static void vhost_net_tx_packet(struct vhost_net
*net
)
322 if (net
->tx_packets
< 1024)
325 net
->tx_zcopy_err
= 0;
328 static void vhost_net_tx_err(struct vhost_net
*net
)
333 static bool vhost_net_tx_select_zcopy(struct vhost_net
*net
)
335 /* TX flush waits for outstanding DMAs to be done.
336 * Don't start new DMAs.
338 return !net
->tx_flush
&&
339 net
->tx_packets
/ 64 >= net
->tx_zcopy_err
;
342 static bool vhost_sock_zcopy(struct socket
*sock
)
344 return unlikely(experimental_zcopytx
) &&
345 sock_flag(sock
->sk
, SOCK_ZEROCOPY
);
348 static bool vhost_sock_xdp(struct socket
*sock
)
350 return sock_flag(sock
->sk
, SOCK_XDP
);
353 /* In case of DMA done not in order in lower device driver for some reason.
354 * upend_idx is used to track end of used idx, done_idx is used to track head
355 * of used idx. Once lower device DMA done contiguously, we will signal KVM
358 static void vhost_zerocopy_signal_used(struct vhost_net
*net
,
359 struct vhost_virtqueue
*vq
)
361 struct vhost_net_virtqueue
*nvq
=
362 container_of(vq
, struct vhost_net_virtqueue
, vq
);
366 for (i
= nvq
->done_idx
; i
!= nvq
->upend_idx
; i
= (i
+ 1) % UIO_MAXIOV
) {
367 if (vq
->heads
[i
].len
== VHOST_DMA_FAILED_LEN
)
368 vhost_net_tx_err(net
);
369 if (VHOST_DMA_IS_DONE(vq
->heads
[i
].len
)) {
370 vq
->heads
[i
].len
= VHOST_DMA_CLEAR_LEN
;
376 add
= min(UIO_MAXIOV
- nvq
->done_idx
, j
);
377 vhost_add_used_and_signal_n(vq
->dev
, vq
,
378 &vq
->heads
[nvq
->done_idx
], add
);
379 nvq
->done_idx
= (nvq
->done_idx
+ add
) % UIO_MAXIOV
;
384 static void vhost_zerocopy_callback(struct sk_buff
*skb
,
385 struct ubuf_info
*ubuf
, bool success
)
387 struct vhost_net_ubuf_ref
*ubufs
= ubuf
->ctx
;
388 struct vhost_virtqueue
*vq
= ubufs
->vq
;
393 /* set len to mark this desc buffers done DMA */
394 vq
->heads
[ubuf
->desc
].len
= success
?
395 VHOST_DMA_DONE_LEN
: VHOST_DMA_FAILED_LEN
;
396 cnt
= vhost_net_ubuf_put(ubufs
);
399 * Trigger polling thread if guest stopped submitting new buffers:
400 * in this case, the refcount after decrement will eventually reach 1.
401 * We also trigger polling periodically after each 16 packets
402 * (the value 16 here is more or less arbitrary, it's tuned to trigger
403 * less than 10% of times).
405 if (cnt
<= 1 || !(cnt
% 16))
406 vhost_poll_queue(&vq
->poll
);
408 rcu_read_unlock_bh();
411 static inline unsigned long busy_clock(void)
413 return local_clock() >> 10;
416 static bool vhost_can_busy_poll(unsigned long endtime
)
418 return likely(!need_resched() && !time_after(busy_clock(), endtime
) &&
419 !signal_pending(current
));
422 static void vhost_net_disable_vq(struct vhost_net
*n
,
423 struct vhost_virtqueue
*vq
)
425 struct vhost_net_virtqueue
*nvq
=
426 container_of(vq
, struct vhost_net_virtqueue
, vq
);
427 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
428 if (!vhost_vq_get_backend(vq
))
430 vhost_poll_stop(poll
);
433 static int vhost_net_enable_vq(struct vhost_net
*n
,
434 struct vhost_virtqueue
*vq
)
436 struct vhost_net_virtqueue
*nvq
=
437 container_of(vq
, struct vhost_net_virtqueue
, vq
);
438 struct vhost_poll
*poll
= n
->poll
+ (nvq
- n
->vqs
);
441 sock
= vhost_vq_get_backend(vq
);
445 return vhost_poll_start(poll
, sock
->file
);
448 static void vhost_net_signal_used(struct vhost_net_virtqueue
*nvq
)
450 struct vhost_virtqueue
*vq
= &nvq
->vq
;
451 struct vhost_dev
*dev
= vq
->dev
;
456 vhost_add_used_and_signal_n(dev
, vq
, vq
->heads
, nvq
->done_idx
);
460 static void vhost_tx_batch(struct vhost_net
*net
,
461 struct vhost_net_virtqueue
*nvq
,
463 struct msghdr
*msghdr
)
465 struct tun_msg_ctl ctl
= {
467 .num
= nvq
->batched_xdp
,
472 if (nvq
->batched_xdp
== 0)
475 msghdr
->msg_control
= &ctl
;
476 err
= sock
->ops
->sendmsg(sock
, msghdr
, 0);
477 if (unlikely(err
< 0)) {
478 vq_err(&nvq
->vq
, "Fail to batch sending packets\n");
480 /* free pages owned by XDP; since this is an unlikely error path,
481 * keep it simple and avoid more complex bulk update for the
484 for (i
= 0; i
< nvq
->batched_xdp
; ++i
)
485 put_page(virt_to_head_page(nvq
->xdp
[i
].data
));
486 nvq
->batched_xdp
= 0;
492 vhost_net_signal_used(nvq
);
493 nvq
->batched_xdp
= 0;
496 static int sock_has_rx_data(struct socket
*sock
)
501 if (sock
->ops
->peek_len
)
502 return sock
->ops
->peek_len(sock
);
504 return skb_queue_empty(&sock
->sk
->sk_receive_queue
);
507 static void vhost_net_busy_poll_try_queue(struct vhost_net
*net
,
508 struct vhost_virtqueue
*vq
)
510 if (!vhost_vq_avail_empty(&net
->dev
, vq
)) {
511 vhost_poll_queue(&vq
->poll
);
512 } else if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
513 vhost_disable_notify(&net
->dev
, vq
);
514 vhost_poll_queue(&vq
->poll
);
518 static void vhost_net_busy_poll(struct vhost_net
*net
,
519 struct vhost_virtqueue
*rvq
,
520 struct vhost_virtqueue
*tvq
,
524 unsigned long busyloop_timeout
;
525 unsigned long endtime
;
527 struct vhost_virtqueue
*vq
= poll_rx
? tvq
: rvq
;
529 /* Try to hold the vq mutex of the paired virtqueue. We can't
530 * use mutex_lock() here since we could not guarantee a
531 * consistenet lock ordering.
533 if (!mutex_trylock(&vq
->mutex
))
536 vhost_disable_notify(&net
->dev
, vq
);
537 sock
= vhost_vq_get_backend(rvq
);
539 busyloop_timeout
= poll_rx
? rvq
->busyloop_timeout
:
540 tvq
->busyloop_timeout
;
543 endtime
= busy_clock() + busyloop_timeout
;
545 while (vhost_can_busy_poll(endtime
)) {
546 if (vhost_has_work(&net
->dev
)) {
547 *busyloop_intr
= true;
551 if ((sock_has_rx_data(sock
) &&
552 !vhost_vq_avail_empty(&net
->dev
, rvq
)) ||
553 !vhost_vq_avail_empty(&net
->dev
, tvq
))
561 if (poll_rx
|| sock_has_rx_data(sock
))
562 vhost_net_busy_poll_try_queue(net
, vq
);
563 else if (!poll_rx
) /* On tx here, sock has no rx data. */
564 vhost_enable_notify(&net
->dev
, rvq
);
566 mutex_unlock(&vq
->mutex
);
569 static int vhost_net_tx_get_vq_desc(struct vhost_net
*net
,
570 struct vhost_net_virtqueue
*tnvq
,
571 unsigned int *out_num
, unsigned int *in_num
,
572 struct msghdr
*msghdr
, bool *busyloop_intr
)
574 struct vhost_net_virtqueue
*rnvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
575 struct vhost_virtqueue
*rvq
= &rnvq
->vq
;
576 struct vhost_virtqueue
*tvq
= &tnvq
->vq
;
578 int r
= vhost_get_vq_desc(tvq
, tvq
->iov
, ARRAY_SIZE(tvq
->iov
),
579 out_num
, in_num
, NULL
, NULL
);
581 if (r
== tvq
->num
&& tvq
->busyloop_timeout
) {
582 /* Flush batched packets first */
583 if (!vhost_sock_zcopy(vhost_vq_get_backend(tvq
)))
584 vhost_tx_batch(net
, tnvq
,
585 vhost_vq_get_backend(tvq
),
588 vhost_net_busy_poll(net
, rvq
, tvq
, busyloop_intr
, false);
590 r
= vhost_get_vq_desc(tvq
, tvq
->iov
, ARRAY_SIZE(tvq
->iov
),
591 out_num
, in_num
, NULL
, NULL
);
597 static bool vhost_exceeds_maxpend(struct vhost_net
*net
)
599 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
600 struct vhost_virtqueue
*vq
= &nvq
->vq
;
602 return (nvq
->upend_idx
+ UIO_MAXIOV
- nvq
->done_idx
) % UIO_MAXIOV
>
603 min_t(unsigned int, VHOST_MAX_PEND
, vq
->num
>> 2);
606 static size_t init_iov_iter(struct vhost_virtqueue
*vq
, struct iov_iter
*iter
,
607 size_t hdr_size
, int out
)
609 /* Skip header. TODO: support TSO. */
610 size_t len
= iov_length(vq
->iov
, out
);
612 iov_iter_init(iter
, WRITE
, vq
->iov
, out
, len
);
613 iov_iter_advance(iter
, hdr_size
);
615 return iov_iter_count(iter
);
618 static int get_tx_bufs(struct vhost_net
*net
,
619 struct vhost_net_virtqueue
*nvq
,
621 unsigned int *out
, unsigned int *in
,
622 size_t *len
, bool *busyloop_intr
)
624 struct vhost_virtqueue
*vq
= &nvq
->vq
;
627 ret
= vhost_net_tx_get_vq_desc(net
, nvq
, out
, in
, msg
, busyloop_intr
);
629 if (ret
< 0 || ret
== vq
->num
)
633 vq_err(vq
, "Unexpected descriptor format for TX: out %d, int %d\n",
639 *len
= init_iov_iter(vq
, &msg
->msg_iter
, nvq
->vhost_hlen
, *out
);
641 vq_err(vq
, "Unexpected header len for TX: %zd expected %zd\n",
642 *len
, nvq
->vhost_hlen
);
649 static bool tx_can_batch(struct vhost_virtqueue
*vq
, size_t total_len
)
651 return total_len
< VHOST_NET_WEIGHT
&&
652 !vhost_vq_avail_empty(vq
->dev
, vq
);
655 static bool vhost_net_page_frag_refill(struct vhost_net
*net
, unsigned int sz
,
656 struct page_frag
*pfrag
, gfp_t gfp
)
659 if (pfrag
->offset
+ sz
<= pfrag
->size
)
661 __page_frag_cache_drain(pfrag
->page
, net
->refcnt_bias
);
665 net
->refcnt_bias
= 0;
666 if (SKB_FRAG_PAGE_ORDER
) {
667 /* Avoid direct reclaim but allow kswapd to wake */
668 pfrag
->page
= alloc_pages((gfp
& ~__GFP_DIRECT_RECLAIM
) |
669 __GFP_COMP
| __GFP_NOWARN
|
671 SKB_FRAG_PAGE_ORDER
);
672 if (likely(pfrag
->page
)) {
673 pfrag
->size
= PAGE_SIZE
<< SKB_FRAG_PAGE_ORDER
;
677 pfrag
->page
= alloc_page(gfp
);
678 if (likely(pfrag
->page
)) {
679 pfrag
->size
= PAGE_SIZE
;
685 net
->refcnt_bias
= USHRT_MAX
;
686 page_ref_add(pfrag
->page
, USHRT_MAX
- 1);
690 #define VHOST_NET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
692 static int vhost_net_build_xdp(struct vhost_net_virtqueue
*nvq
,
693 struct iov_iter
*from
)
695 struct vhost_virtqueue
*vq
= &nvq
->vq
;
696 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
,
698 struct socket
*sock
= vhost_vq_get_backend(vq
);
699 struct page_frag
*alloc_frag
= &net
->page_frag
;
700 struct virtio_net_hdr
*gso
;
701 struct xdp_buff
*xdp
= &nvq
->xdp
[nvq
->batched_xdp
];
702 struct tun_xdp_hdr
*hdr
;
703 size_t len
= iov_iter_count(from
);
704 int headroom
= vhost_sock_xdp(sock
) ? XDP_PACKET_HEADROOM
: 0;
705 int buflen
= SKB_DATA_ALIGN(sizeof(struct skb_shared_info
));
706 int pad
= SKB_DATA_ALIGN(VHOST_NET_RX_PAD
+ headroom
+ nvq
->sock_hlen
);
707 int sock_hlen
= nvq
->sock_hlen
;
711 if (unlikely(len
< nvq
->sock_hlen
))
714 if (SKB_DATA_ALIGN(len
+ pad
) +
715 SKB_DATA_ALIGN(sizeof(struct skb_shared_info
)) > PAGE_SIZE
)
718 buflen
+= SKB_DATA_ALIGN(len
+ pad
);
719 alloc_frag
->offset
= ALIGN((u64
)alloc_frag
->offset
, SMP_CACHE_BYTES
);
720 if (unlikely(!vhost_net_page_frag_refill(net
, buflen
,
721 alloc_frag
, GFP_KERNEL
)))
724 buf
= (char *)page_address(alloc_frag
->page
) + alloc_frag
->offset
;
725 copied
= copy_page_from_iter(alloc_frag
->page
,
727 offsetof(struct tun_xdp_hdr
, gso
),
729 if (copied
!= sock_hlen
)
735 if ((gso
->flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
736 vhost16_to_cpu(vq
, gso
->csum_start
) +
737 vhost16_to_cpu(vq
, gso
->csum_offset
) + 2 >
738 vhost16_to_cpu(vq
, gso
->hdr_len
)) {
739 gso
->hdr_len
= cpu_to_vhost16(vq
,
740 vhost16_to_cpu(vq
, gso
->csum_start
) +
741 vhost16_to_cpu(vq
, gso
->csum_offset
) + 2);
743 if (vhost16_to_cpu(vq
, gso
->hdr_len
) > len
)
748 copied
= copy_page_from_iter(alloc_frag
->page
,
749 alloc_frag
->offset
+ pad
,
754 xdp_init_buff(xdp
, buflen
, NULL
);
755 xdp_prepare_buff(xdp
, buf
, pad
, len
, true);
756 hdr
->buflen
= buflen
;
759 alloc_frag
->offset
+= buflen
;
766 static void handle_tx_copy(struct vhost_net
*net
, struct socket
*sock
)
768 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
769 struct vhost_virtqueue
*vq
= &nvq
->vq
;
772 struct msghdr msg
= {
777 .msg_flags
= MSG_DONTWAIT
,
779 size_t len
, total_len
= 0;
782 bool sock_can_batch
= (sock
->sk
->sk_sndbuf
== INT_MAX
);
785 bool busyloop_intr
= false;
787 if (nvq
->done_idx
== VHOST_NET_BATCH
)
788 vhost_tx_batch(net
, nvq
, sock
, &msg
);
790 head
= get_tx_bufs(net
, nvq
, &msg
, &out
, &in
, &len
,
792 /* On error, stop handling until the next kick. */
793 if (unlikely(head
< 0))
795 /* Nothing new? Wait for eventfd to tell us they refilled. */
796 if (head
== vq
->num
) {
797 if (unlikely(busyloop_intr
)) {
798 vhost_poll_queue(&vq
->poll
);
799 } else if (unlikely(vhost_enable_notify(&net
->dev
,
801 vhost_disable_notify(&net
->dev
, vq
);
809 /* For simplicity, TX batching is only enabled if
810 * sndbuf is unlimited.
812 if (sock_can_batch
) {
813 err
= vhost_net_build_xdp(nvq
, &msg
.msg_iter
);
816 } else if (unlikely(err
!= -ENOSPC
)) {
817 vhost_tx_batch(net
, nvq
, sock
, &msg
);
818 vhost_discard_vq_desc(vq
, 1);
819 vhost_net_enable_vq(net
, vq
);
823 /* We can't build XDP buff, go for single
824 * packet path but let's flush batched
827 vhost_tx_batch(net
, nvq
, sock
, &msg
);
828 msg
.msg_control
= NULL
;
830 if (tx_can_batch(vq
, total_len
))
831 msg
.msg_flags
|= MSG_MORE
;
833 msg
.msg_flags
&= ~MSG_MORE
;
836 err
= sock
->ops
->sendmsg(sock
, &msg
, len
);
837 if (unlikely(err
< 0)) {
838 if (err
== -EAGAIN
|| err
== -ENOMEM
|| err
== -ENOBUFS
) {
839 vhost_discard_vq_desc(vq
, 1);
840 vhost_net_enable_vq(net
, vq
);
843 pr_debug("Fail to send packet: err %d", err
);
844 } else if (unlikely(err
!= len
))
845 pr_debug("Truncated TX packet: len %d != %zd\n",
848 vq
->heads
[nvq
->done_idx
].id
= cpu_to_vhost32(vq
, head
);
849 vq
->heads
[nvq
->done_idx
].len
= 0;
851 } while (likely(!vhost_exceeds_weight(vq
, ++sent_pkts
, total_len
)));
853 vhost_tx_batch(net
, nvq
, sock
, &msg
);
856 static void handle_tx_zerocopy(struct vhost_net
*net
, struct socket
*sock
)
858 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
859 struct vhost_virtqueue
*vq
= &nvq
->vq
;
862 struct msghdr msg
= {
867 .msg_flags
= MSG_DONTWAIT
,
869 struct tun_msg_ctl ctl
;
870 size_t len
, total_len
= 0;
872 struct vhost_net_ubuf_ref
*ubufs
;
873 struct ubuf_info
*ubuf
;
880 /* Release DMAs done buffers first */
881 vhost_zerocopy_signal_used(net
, vq
);
883 busyloop_intr
= false;
884 head
= get_tx_bufs(net
, nvq
, &msg
, &out
, &in
, &len
,
886 /* On error, stop handling until the next kick. */
887 if (unlikely(head
< 0))
889 /* Nothing new? Wait for eventfd to tell us they refilled. */
890 if (head
== vq
->num
) {
891 if (unlikely(busyloop_intr
)) {
892 vhost_poll_queue(&vq
->poll
);
893 } else if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
894 vhost_disable_notify(&net
->dev
, vq
);
900 zcopy_used
= len
>= VHOST_GOODCOPY_LEN
901 && !vhost_exceeds_maxpend(net
)
902 && vhost_net_tx_select_zcopy(net
);
904 /* use msg_control to pass vhost zerocopy ubuf info to skb */
906 ubuf
= nvq
->ubuf_info
+ nvq
->upend_idx
;
907 vq
->heads
[nvq
->upend_idx
].id
= cpu_to_vhost32(vq
, head
);
908 vq
->heads
[nvq
->upend_idx
].len
= VHOST_DMA_IN_PROGRESS
;
909 ubuf
->callback
= vhost_zerocopy_callback
;
910 ubuf
->ctx
= nvq
->ubufs
;
911 ubuf
->desc
= nvq
->upend_idx
;
912 ubuf
->flags
= SKBFL_ZEROCOPY_FRAG
;
913 refcount_set(&ubuf
->refcnt
, 1);
914 msg
.msg_control
= &ctl
;
915 ctl
.type
= TUN_MSG_UBUF
;
917 msg
.msg_controllen
= sizeof(ctl
);
919 atomic_inc(&ubufs
->refcount
);
920 nvq
->upend_idx
= (nvq
->upend_idx
+ 1) % UIO_MAXIOV
;
922 msg
.msg_control
= NULL
;
926 if (tx_can_batch(vq
, total_len
) &&
927 likely(!vhost_exceeds_maxpend(net
))) {
928 msg
.msg_flags
|= MSG_MORE
;
930 msg
.msg_flags
&= ~MSG_MORE
;
933 err
= sock
->ops
->sendmsg(sock
, &msg
, len
);
934 if (unlikely(err
< 0)) {
936 if (vq
->heads
[ubuf
->desc
].len
== VHOST_DMA_IN_PROGRESS
)
937 vhost_net_ubuf_put(ubufs
);
938 nvq
->upend_idx
= ((unsigned)nvq
->upend_idx
- 1)
941 if (err
== -EAGAIN
|| err
== -ENOMEM
|| err
== -ENOBUFS
) {
942 vhost_discard_vq_desc(vq
, 1);
943 vhost_net_enable_vq(net
, vq
);
946 pr_debug("Fail to send packet: err %d", err
);
947 } else if (unlikely(err
!= len
))
948 pr_debug("Truncated TX packet: "
949 " len %d != %zd\n", err
, len
);
951 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
953 vhost_zerocopy_signal_used(net
, vq
);
954 vhost_net_tx_packet(net
);
955 } while (likely(!vhost_exceeds_weight(vq
, ++sent_pkts
, total_len
)));
958 /* Expects to be always run from workqueue - which acts as
959 * read-size critical section for our kind of RCU. */
960 static void handle_tx(struct vhost_net
*net
)
962 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
963 struct vhost_virtqueue
*vq
= &nvq
->vq
;
966 mutex_lock_nested(&vq
->mutex
, VHOST_NET_VQ_TX
);
967 sock
= vhost_vq_get_backend(vq
);
971 if (!vq_meta_prefetch(vq
))
974 vhost_disable_notify(&net
->dev
, vq
);
975 vhost_net_disable_vq(net
, vq
);
977 if (vhost_sock_zcopy(sock
))
978 handle_tx_zerocopy(net
, sock
);
980 handle_tx_copy(net
, sock
);
983 mutex_unlock(&vq
->mutex
);
986 static int peek_head_len(struct vhost_net_virtqueue
*rvq
, struct sock
*sk
)
988 struct sk_buff
*head
;
993 return vhost_net_buf_peek(rvq
);
995 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
996 head
= skb_peek(&sk
->sk_receive_queue
);
999 if (skb_vlan_tag_present(head
))
1003 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
1007 static int vhost_net_rx_peek_head_len(struct vhost_net
*net
, struct sock
*sk
,
1008 bool *busyloop_intr
)
1010 struct vhost_net_virtqueue
*rnvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
1011 struct vhost_net_virtqueue
*tnvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
1012 struct vhost_virtqueue
*rvq
= &rnvq
->vq
;
1013 struct vhost_virtqueue
*tvq
= &tnvq
->vq
;
1014 int len
= peek_head_len(rnvq
, sk
);
1016 if (!len
&& rvq
->busyloop_timeout
) {
1017 /* Flush batched heads first */
1018 vhost_net_signal_used(rnvq
);
1019 /* Both tx vq and rx socket were polled here */
1020 vhost_net_busy_poll(net
, rvq
, tvq
, busyloop_intr
, true);
1022 len
= peek_head_len(rnvq
, sk
);
1028 /* This is a multi-buffer version of vhost_get_desc, that works if
1029 * vq has read descriptors only.
1030 * @vq - the relevant virtqueue
1031 * @datalen - data length we'll be reading
1032 * @iovcount - returned count of io vectors we fill
1034 * @log_num - log offset
1035 * @quota - headcount quota, 1 for big buffer
1036 * returns number of buffer heads allocated, negative on error
1038 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
1039 struct vring_used_elem
*heads
,
1042 struct vhost_log
*log
,
1046 unsigned int out
, in
;
1051 /* len is always initialized before use since we are always called with
1056 while (datalen
> 0 && headcount
< quota
) {
1057 if (unlikely(seg
>= UIO_MAXIOV
)) {
1061 r
= vhost_get_vq_desc(vq
, vq
->iov
+ seg
,
1062 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
1064 if (unlikely(r
< 0))
1072 if (unlikely(out
|| in
<= 0)) {
1073 vq_err(vq
, "unexpected descriptor format for RX: "
1074 "out %d, in %d\n", out
, in
);
1078 if (unlikely(log
)) {
1082 heads
[headcount
].id
= cpu_to_vhost32(vq
, d
);
1083 len
= iov_length(vq
->iov
+ seg
, in
);
1084 heads
[headcount
].len
= cpu_to_vhost32(vq
, len
);
1089 heads
[headcount
- 1].len
= cpu_to_vhost32(vq
, len
+ datalen
);
1094 /* Detect overrun */
1095 if (unlikely(datalen
> 0)) {
1101 vhost_discard_vq_desc(vq
, headcount
);
1105 /* Expects to be always run from workqueue - which acts as
1106 * read-size critical section for our kind of RCU. */
1107 static void handle_rx(struct vhost_net
*net
)
1109 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
1110 struct vhost_virtqueue
*vq
= &nvq
->vq
;
1112 struct vhost_log
*vq_log
;
1113 struct msghdr msg
= {
1116 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
1117 .msg_controllen
= 0,
1118 .msg_flags
= MSG_DONTWAIT
,
1120 struct virtio_net_hdr hdr
= {
1122 .gso_type
= VIRTIO_NET_HDR_GSO_NONE
1124 size_t total_len
= 0;
1127 size_t vhost_hlen
, sock_hlen
;
1128 size_t vhost_len
, sock_len
;
1129 bool busyloop_intr
= false;
1130 struct socket
*sock
;
1131 struct iov_iter fixup
;
1132 __virtio16 num_buffers
;
1135 mutex_lock_nested(&vq
->mutex
, VHOST_NET_VQ_RX
);
1136 sock
= vhost_vq_get_backend(vq
);
1140 if (!vq_meta_prefetch(vq
))
1143 vhost_disable_notify(&net
->dev
, vq
);
1144 vhost_net_disable_vq(net
, vq
);
1146 vhost_hlen
= nvq
->vhost_hlen
;
1147 sock_hlen
= nvq
->sock_hlen
;
1149 vq_log
= unlikely(vhost_has_feature(vq
, VHOST_F_LOG_ALL
)) ?
1151 mergeable
= vhost_has_feature(vq
, VIRTIO_NET_F_MRG_RXBUF
);
1154 sock_len
= vhost_net_rx_peek_head_len(net
, sock
->sk
,
1158 sock_len
+= sock_hlen
;
1159 vhost_len
= sock_len
+ vhost_hlen
;
1160 headcount
= get_rx_bufs(vq
, vq
->heads
+ nvq
->done_idx
,
1161 vhost_len
, &in
, vq_log
, &log
,
1162 likely(mergeable
) ? UIO_MAXIOV
: 1);
1163 /* On error, stop handling until the next kick. */
1164 if (unlikely(headcount
< 0))
1166 /* OK, now we need to know about added descriptors. */
1168 if (unlikely(busyloop_intr
)) {
1169 vhost_poll_queue(&vq
->poll
);
1170 } else if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
1171 /* They have slipped one in as we were
1172 * doing that: check again. */
1173 vhost_disable_notify(&net
->dev
, vq
);
1176 /* Nothing new? Wait for eventfd to tell us
1180 busyloop_intr
= false;
1182 msg
.msg_control
= vhost_net_buf_consume(&nvq
->rxq
);
1183 /* On overrun, truncate and discard */
1184 if (unlikely(headcount
> UIO_MAXIOV
)) {
1185 iov_iter_init(&msg
.msg_iter
, READ
, vq
->iov
, 1, 1);
1186 err
= sock
->ops
->recvmsg(sock
, &msg
,
1187 1, MSG_DONTWAIT
| MSG_TRUNC
);
1188 pr_debug("Discarded rx packet: len %zd\n", sock_len
);
1191 /* We don't need to be notified again. */
1192 iov_iter_init(&msg
.msg_iter
, READ
, vq
->iov
, in
, vhost_len
);
1193 fixup
= msg
.msg_iter
;
1194 if (unlikely((vhost_hlen
))) {
1195 /* We will supply the header ourselves
1196 * TODO: support TSO.
1198 iov_iter_advance(&msg
.msg_iter
, vhost_hlen
);
1200 err
= sock
->ops
->recvmsg(sock
, &msg
,
1201 sock_len
, MSG_DONTWAIT
| MSG_TRUNC
);
1202 /* Userspace might have consumed the packet meanwhile:
1203 * it's not supposed to do this usually, but might be hard
1204 * to prevent. Discard data we got (if any) and keep going. */
1205 if (unlikely(err
!= sock_len
)) {
1206 pr_debug("Discarded rx packet: "
1207 " len %d, expected %zd\n", err
, sock_len
);
1208 vhost_discard_vq_desc(vq
, headcount
);
1211 /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
1212 if (unlikely(vhost_hlen
)) {
1213 if (copy_to_iter(&hdr
, sizeof(hdr
),
1214 &fixup
) != sizeof(hdr
)) {
1215 vq_err(vq
, "Unable to write vnet_hdr "
1216 "at addr %p\n", vq
->iov
->iov_base
);
1220 /* Header came from socket; we'll need to patch
1221 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF
1223 iov_iter_advance(&fixup
, sizeof(hdr
));
1225 /* TODO: Should check and handle checksum. */
1227 num_buffers
= cpu_to_vhost16(vq
, headcount
);
1228 if (likely(mergeable
) &&
1229 copy_to_iter(&num_buffers
, sizeof num_buffers
,
1230 &fixup
) != sizeof num_buffers
) {
1231 vq_err(vq
, "Failed num_buffers write");
1232 vhost_discard_vq_desc(vq
, headcount
);
1235 nvq
->done_idx
+= headcount
;
1236 if (nvq
->done_idx
> VHOST_NET_BATCH
)
1237 vhost_net_signal_used(nvq
);
1238 if (unlikely(vq_log
))
1239 vhost_log_write(vq
, vq_log
, log
, vhost_len
,
1241 total_len
+= vhost_len
;
1242 } while (likely(!vhost_exceeds_weight(vq
, ++recv_pkts
, total_len
)));
1244 if (unlikely(busyloop_intr
))
1245 vhost_poll_queue(&vq
->poll
);
1247 vhost_net_enable_vq(net
, vq
);
1249 vhost_net_signal_used(nvq
);
1250 mutex_unlock(&vq
->mutex
);
1253 static void handle_tx_kick(struct vhost_work
*work
)
1255 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
1257 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
1262 static void handle_rx_kick(struct vhost_work
*work
)
1264 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
1266 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
1271 static void handle_tx_net(struct vhost_work
*work
)
1273 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
1274 poll
[VHOST_NET_VQ_TX
].work
);
1278 static void handle_rx_net(struct vhost_work
*work
)
1280 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
1281 poll
[VHOST_NET_VQ_RX
].work
);
1285 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
1287 struct vhost_net
*n
;
1288 struct vhost_dev
*dev
;
1289 struct vhost_virtqueue
**vqs
;
1291 struct xdp_buff
*xdp
;
1294 n
= kvmalloc(sizeof *n
, GFP_KERNEL
| __GFP_RETRY_MAYFAIL
);
1297 vqs
= kmalloc_array(VHOST_NET_VQ_MAX
, sizeof(*vqs
), GFP_KERNEL
);
1303 queue
= kmalloc_array(VHOST_NET_BATCH
, sizeof(void *),
1310 n
->vqs
[VHOST_NET_VQ_RX
].rxq
.queue
= queue
;
1312 xdp
= kmalloc_array(VHOST_NET_BATCH
, sizeof(*xdp
), GFP_KERNEL
);
1319 n
->vqs
[VHOST_NET_VQ_TX
].xdp
= xdp
;
1322 vqs
[VHOST_NET_VQ_TX
] = &n
->vqs
[VHOST_NET_VQ_TX
].vq
;
1323 vqs
[VHOST_NET_VQ_RX
] = &n
->vqs
[VHOST_NET_VQ_RX
].vq
;
1324 n
->vqs
[VHOST_NET_VQ_TX
].vq
.handle_kick
= handle_tx_kick
;
1325 n
->vqs
[VHOST_NET_VQ_RX
].vq
.handle_kick
= handle_rx_kick
;
1326 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
1327 n
->vqs
[i
].ubufs
= NULL
;
1328 n
->vqs
[i
].ubuf_info
= NULL
;
1329 n
->vqs
[i
].upend_idx
= 0;
1330 n
->vqs
[i
].done_idx
= 0;
1331 n
->vqs
[i
].batched_xdp
= 0;
1332 n
->vqs
[i
].vhost_hlen
= 0;
1333 n
->vqs
[i
].sock_hlen
= 0;
1334 n
->vqs
[i
].rx_ring
= NULL
;
1335 vhost_net_buf_init(&n
->vqs
[i
].rxq
);
1337 vhost_dev_init(dev
, vqs
, VHOST_NET_VQ_MAX
,
1338 UIO_MAXIOV
+ VHOST_NET_BATCH
,
1339 VHOST_NET_PKT_WEIGHT
, VHOST_NET_WEIGHT
, true,
1342 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, EPOLLOUT
, dev
);
1343 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, EPOLLIN
, dev
);
1345 f
->private_data
= n
;
1346 n
->page_frag
.page
= NULL
;
1352 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
1353 struct vhost_virtqueue
*vq
)
1355 struct socket
*sock
;
1356 struct vhost_net_virtqueue
*nvq
=
1357 container_of(vq
, struct vhost_net_virtqueue
, vq
);
1359 mutex_lock(&vq
->mutex
);
1360 sock
= vhost_vq_get_backend(vq
);
1361 vhost_net_disable_vq(n
, vq
);
1362 vhost_vq_set_backend(vq
, NULL
);
1363 vhost_net_buf_unproduce(nvq
);
1364 nvq
->rx_ring
= NULL
;
1365 mutex_unlock(&vq
->mutex
);
1369 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
1370 struct socket
**rx_sock
)
1372 *tx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_TX
].vq
);
1373 *rx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_RX
].vq
);
1376 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
1378 vhost_poll_flush(n
->poll
+ index
);
1379 vhost_poll_flush(&n
->vqs
[index
].vq
.poll
);
1382 static void vhost_net_flush(struct vhost_net
*n
)
1384 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
1385 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
1386 if (n
->vqs
[VHOST_NET_VQ_TX
].ubufs
) {
1387 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1389 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1390 /* Wait for all lower device DMAs done. */
1391 vhost_net_ubuf_put_and_wait(n
->vqs
[VHOST_NET_VQ_TX
].ubufs
);
1392 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1393 n
->tx_flush
= false;
1394 atomic_set(&n
->vqs
[VHOST_NET_VQ_TX
].ubufs
->refcount
, 1);
1395 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1399 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
1401 struct vhost_net
*n
= f
->private_data
;
1402 struct socket
*tx_sock
;
1403 struct socket
*rx_sock
;
1405 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
1407 vhost_dev_stop(&n
->dev
);
1408 vhost_dev_cleanup(&n
->dev
);
1409 vhost_net_vq_reset(n
);
1411 sockfd_put(tx_sock
);
1413 sockfd_put(rx_sock
);
1414 /* Make sure no callbacks are outstanding */
1416 /* We do an extra flush before freeing memory,
1417 * since jobs can re-queue themselves. */
1419 kfree(n
->vqs
[VHOST_NET_VQ_RX
].rxq
.queue
);
1420 kfree(n
->vqs
[VHOST_NET_VQ_TX
].xdp
);
1422 if (n
->page_frag
.page
)
1423 __page_frag_cache_drain(n
->page_frag
.page
, n
->refcnt_bias
);
1428 static struct socket
*get_raw_socket(int fd
)
1431 struct socket
*sock
= sockfd_lookup(fd
, &r
);
1434 return ERR_PTR(-ENOTSOCK
);
1436 /* Parameter checking */
1437 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
1438 r
= -ESOCKTNOSUPPORT
;
1442 if (sock
->sk
->sk_family
!= AF_PACKET
) {
1452 static struct ptr_ring
*get_tap_ptr_ring(int fd
)
1454 struct ptr_ring
*ring
;
1455 struct file
*file
= fget(fd
);
1459 ring
= tun_get_tx_ring(file
);
1462 ring
= tap_get_ptr_ring(file
);
1471 static struct socket
*get_tap_socket(int fd
)
1473 struct file
*file
= fget(fd
);
1474 struct socket
*sock
;
1477 return ERR_PTR(-EBADF
);
1478 sock
= tun_get_socket(file
);
1481 sock
= tap_get_socket(file
);
1487 static struct socket
*get_socket(int fd
)
1489 struct socket
*sock
;
1491 /* special case to disable backend */
1494 sock
= get_raw_socket(fd
);
1497 sock
= get_tap_socket(fd
);
1500 return ERR_PTR(-ENOTSOCK
);
1503 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
1505 struct socket
*sock
, *oldsock
;
1506 struct vhost_virtqueue
*vq
;
1507 struct vhost_net_virtqueue
*nvq
;
1508 struct vhost_net_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
1511 mutex_lock(&n
->dev
.mutex
);
1512 r
= vhost_dev_check_owner(&n
->dev
);
1516 if (index
>= VHOST_NET_VQ_MAX
) {
1520 vq
= &n
->vqs
[index
].vq
;
1521 nvq
= &n
->vqs
[index
];
1522 mutex_lock(&vq
->mutex
);
1524 /* Verify that ring has been setup correctly. */
1525 if (!vhost_vq_access_ok(vq
)) {
1529 sock
= get_socket(fd
);
1535 /* start polling new socket */
1536 oldsock
= vhost_vq_get_backend(vq
);
1537 if (sock
!= oldsock
) {
1538 ubufs
= vhost_net_ubuf_alloc(vq
,
1539 sock
&& vhost_sock_zcopy(sock
));
1540 if (IS_ERR(ubufs
)) {
1545 vhost_net_disable_vq(n
, vq
);
1546 vhost_vq_set_backend(vq
, sock
);
1547 vhost_net_buf_unproduce(nvq
);
1548 r
= vhost_vq_init_access(vq
);
1551 r
= vhost_net_enable_vq(n
, vq
);
1554 if (index
== VHOST_NET_VQ_RX
)
1555 nvq
->rx_ring
= get_tap_ptr_ring(fd
);
1557 oldubufs
= nvq
->ubufs
;
1561 n
->tx_zcopy_err
= 0;
1562 n
->tx_flush
= false;
1565 mutex_unlock(&vq
->mutex
);
1568 vhost_net_ubuf_put_wait_and_free(oldubufs
);
1569 mutex_lock(&vq
->mutex
);
1570 vhost_zerocopy_signal_used(n
, vq
);
1571 mutex_unlock(&vq
->mutex
);
1575 vhost_net_flush_vq(n
, index
);
1576 sockfd_put(oldsock
);
1579 mutex_unlock(&n
->dev
.mutex
);
1583 vhost_vq_set_backend(vq
, oldsock
);
1584 vhost_net_enable_vq(n
, vq
);
1586 vhost_net_ubuf_put_wait_and_free(ubufs
);
1591 mutex_unlock(&vq
->mutex
);
1593 mutex_unlock(&n
->dev
.mutex
);
1597 static long vhost_net_reset_owner(struct vhost_net
*n
)
1599 struct socket
*tx_sock
= NULL
;
1600 struct socket
*rx_sock
= NULL
;
1602 struct vhost_iotlb
*umem
;
1604 mutex_lock(&n
->dev
.mutex
);
1605 err
= vhost_dev_check_owner(&n
->dev
);
1608 umem
= vhost_dev_reset_owner_prepare();
1613 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
1615 vhost_dev_stop(&n
->dev
);
1616 vhost_dev_reset_owner(&n
->dev
, umem
);
1617 vhost_net_vq_reset(n
);
1619 mutex_unlock(&n
->dev
.mutex
);
1621 sockfd_put(tx_sock
);
1623 sockfd_put(rx_sock
);
1627 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
1629 size_t vhost_hlen
, sock_hlen
, hdr_len
;
1632 hdr_len
= (features
& ((1ULL << VIRTIO_NET_F_MRG_RXBUF
) |
1633 (1ULL << VIRTIO_F_VERSION_1
))) ?
1634 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
1635 sizeof(struct virtio_net_hdr
);
1636 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
1637 /* vhost provides vnet_hdr */
1638 vhost_hlen
= hdr_len
;
1641 /* socket provides vnet_hdr */
1643 sock_hlen
= hdr_len
;
1645 mutex_lock(&n
->dev
.mutex
);
1646 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
1647 !vhost_log_access_ok(&n
->dev
))
1650 if ((features
& (1ULL << VIRTIO_F_ACCESS_PLATFORM
))) {
1651 if (vhost_init_device_iotlb(&n
->dev
, true))
1655 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
1656 mutex_lock(&n
->vqs
[i
].vq
.mutex
);
1657 n
->vqs
[i
].vq
.acked_features
= features
;
1658 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
1659 n
->vqs
[i
].sock_hlen
= sock_hlen
;
1660 mutex_unlock(&n
->vqs
[i
].vq
.mutex
);
1662 mutex_unlock(&n
->dev
.mutex
);
1666 mutex_unlock(&n
->dev
.mutex
);
1670 static long vhost_net_set_owner(struct vhost_net
*n
)
1674 mutex_lock(&n
->dev
.mutex
);
1675 if (vhost_dev_has_owner(&n
->dev
)) {
1679 r
= vhost_net_set_ubuf_info(n
);
1682 r
= vhost_dev_set_owner(&n
->dev
);
1684 vhost_net_clear_ubuf_info(n
);
1687 mutex_unlock(&n
->dev
.mutex
);
1691 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
1694 struct vhost_net
*n
= f
->private_data
;
1695 void __user
*argp
= (void __user
*)arg
;
1696 u64 __user
*featurep
= argp
;
1697 struct vhost_vring_file backend
;
1702 case VHOST_NET_SET_BACKEND
:
1703 if (copy_from_user(&backend
, argp
, sizeof backend
))
1705 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
1706 case VHOST_GET_FEATURES
:
1707 features
= VHOST_NET_FEATURES
;
1708 if (copy_to_user(featurep
, &features
, sizeof features
))
1711 case VHOST_SET_FEATURES
:
1712 if (copy_from_user(&features
, featurep
, sizeof features
))
1714 if (features
& ~VHOST_NET_FEATURES
)
1716 return vhost_net_set_features(n
, features
);
1717 case VHOST_GET_BACKEND_FEATURES
:
1718 features
= VHOST_NET_BACKEND_FEATURES
;
1719 if (copy_to_user(featurep
, &features
, sizeof(features
)))
1722 case VHOST_SET_BACKEND_FEATURES
:
1723 if (copy_from_user(&features
, featurep
, sizeof(features
)))
1725 if (features
& ~VHOST_NET_BACKEND_FEATURES
)
1727 vhost_set_backend_features(&n
->dev
, features
);
1729 case VHOST_RESET_OWNER
:
1730 return vhost_net_reset_owner(n
);
1731 case VHOST_SET_OWNER
:
1732 return vhost_net_set_owner(n
);
1734 mutex_lock(&n
->dev
.mutex
);
1735 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, argp
);
1736 if (r
== -ENOIOCTLCMD
)
1737 r
= vhost_vring_ioctl(&n
->dev
, ioctl
, argp
);
1740 mutex_unlock(&n
->dev
.mutex
);
1745 static ssize_t
vhost_net_chr_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
1747 struct file
*file
= iocb
->ki_filp
;
1748 struct vhost_net
*n
= file
->private_data
;
1749 struct vhost_dev
*dev
= &n
->dev
;
1750 int noblock
= file
->f_flags
& O_NONBLOCK
;
1752 return vhost_chr_read_iter(dev
, to
, noblock
);
1755 static ssize_t
vhost_net_chr_write_iter(struct kiocb
*iocb
,
1756 struct iov_iter
*from
)
1758 struct file
*file
= iocb
->ki_filp
;
1759 struct vhost_net
*n
= file
->private_data
;
1760 struct vhost_dev
*dev
= &n
->dev
;
1762 return vhost_chr_write_iter(dev
, from
);
1765 static __poll_t
vhost_net_chr_poll(struct file
*file
, poll_table
*wait
)
1767 struct vhost_net
*n
= file
->private_data
;
1768 struct vhost_dev
*dev
= &n
->dev
;
1770 return vhost_chr_poll(file
, dev
, wait
);
1773 static const struct file_operations vhost_net_fops
= {
1774 .owner
= THIS_MODULE
,
1775 .release
= vhost_net_release
,
1776 .read_iter
= vhost_net_chr_read_iter
,
1777 .write_iter
= vhost_net_chr_write_iter
,
1778 .poll
= vhost_net_chr_poll
,
1779 .unlocked_ioctl
= vhost_net_ioctl
,
1780 .compat_ioctl
= compat_ptr_ioctl
,
1781 .open
= vhost_net_open
,
1782 .llseek
= noop_llseek
,
1785 static struct miscdevice vhost_net_misc
= {
1786 .minor
= VHOST_NET_MINOR
,
1787 .name
= "vhost-net",
1788 .fops
= &vhost_net_fops
,
1791 static int vhost_net_init(void)
1793 if (experimental_zcopytx
)
1794 vhost_net_enable_zcopy(VHOST_NET_VQ_TX
);
1795 return misc_register(&vhost_net_misc
);
1797 module_init(vhost_net_init
);
1799 static void vhost_net_exit(void)
1801 misc_deregister(&vhost_net_misc
);
1803 module_exit(vhost_net_exit
);
1805 MODULE_VERSION("0.0.1");
1806 MODULE_LICENSE("GPL v2");
1807 MODULE_AUTHOR("Michael S. Tsirkin");
1808 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1809 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
1810 MODULE_ALIAS("devname:vhost-net");