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
)
81 VHOST_NET_BACKEND_FEATURES
= (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2
)
90 struct vhost_net_ubuf_ref
{
91 /* refcount follows semantics similar to kref:
92 * 0: object is released
93 * 1: no outstanding ubufs
94 * >1: outstanding ubufs
97 wait_queue_head_t wait
;
98 struct vhost_virtqueue
*vq
;
101 #define VHOST_NET_BATCH 64
102 struct vhost_net_buf
{
108 struct vhost_net_virtqueue
{
109 struct vhost_virtqueue vq
;
112 /* vhost zerocopy support fields below: */
113 /* last used idx for outstanding DMA zerocopy buffers */
115 /* For TX, first used idx for DMA done zerocopy buffers
116 * For RX, number of batched heads
119 /* Number of XDP frames batched */
121 /* an array of userspace buffers info */
122 struct ubuf_info
*ubuf_info
;
123 /* Reference counting for outstanding ubufs.
124 * Protected by vq mutex. Writers must also take device mutex. */
125 struct vhost_net_ubuf_ref
*ubufs
;
126 struct ptr_ring
*rx_ring
;
127 struct vhost_net_buf rxq
;
128 /* Batched XDP buffs */
129 struct xdp_buff
*xdp
;
133 struct vhost_dev dev
;
134 struct vhost_net_virtqueue vqs
[VHOST_NET_VQ_MAX
];
135 struct vhost_poll poll
[VHOST_NET_VQ_MAX
];
136 /* Number of TX recently submitted.
137 * Protected by tx vq lock. */
139 /* Number of times zerocopy TX recently failed.
140 * Protected by tx vq lock. */
141 unsigned tx_zcopy_err
;
142 /* Flush in progress. Protected by tx vq lock. */
144 /* Private page frag */
145 struct page_frag page_frag
;
146 /* Refcount bias of page frag */
150 static unsigned vhost_net_zcopy_mask __read_mostly
;
152 static void *vhost_net_buf_get_ptr(struct vhost_net_buf
*rxq
)
154 if (rxq
->tail
!= rxq
->head
)
155 return rxq
->queue
[rxq
->head
];
160 static int vhost_net_buf_get_size(struct vhost_net_buf
*rxq
)
162 return rxq
->tail
- rxq
->head
;
165 static int vhost_net_buf_is_empty(struct vhost_net_buf
*rxq
)
167 return rxq
->tail
== rxq
->head
;
170 static void *vhost_net_buf_consume(struct vhost_net_buf
*rxq
)
172 void *ret
= vhost_net_buf_get_ptr(rxq
);
177 static int vhost_net_buf_produce(struct vhost_net_virtqueue
*nvq
)
179 struct vhost_net_buf
*rxq
= &nvq
->rxq
;
182 rxq
->tail
= ptr_ring_consume_batched(nvq
->rx_ring
, rxq
->queue
,
187 static void vhost_net_buf_unproduce(struct vhost_net_virtqueue
*nvq
)
189 struct vhost_net_buf
*rxq
= &nvq
->rxq
;
191 if (nvq
->rx_ring
&& !vhost_net_buf_is_empty(rxq
)) {
192 ptr_ring_unconsume(nvq
->rx_ring
, rxq
->queue
+ rxq
->head
,
193 vhost_net_buf_get_size(rxq
),
195 rxq
->head
= rxq
->tail
= 0;
199 static int vhost_net_buf_peek_len(void *ptr
)
201 if (tun_is_xdp_frame(ptr
)) {
202 struct xdp_frame
*xdpf
= tun_ptr_to_xdp(ptr
);
207 return __skb_array_len_with_tag(ptr
);
210 static int vhost_net_buf_peek(struct vhost_net_virtqueue
*nvq
)
212 struct vhost_net_buf
*rxq
= &nvq
->rxq
;
214 if (!vhost_net_buf_is_empty(rxq
))
217 if (!vhost_net_buf_produce(nvq
))
221 return vhost_net_buf_peek_len(vhost_net_buf_get_ptr(rxq
));
224 static void vhost_net_buf_init(struct vhost_net_buf
*rxq
)
226 rxq
->head
= rxq
->tail
= 0;
229 static void vhost_net_enable_zcopy(int vq
)
231 vhost_net_zcopy_mask
|= 0x1 << vq
;
234 static struct vhost_net_ubuf_ref
*
235 vhost_net_ubuf_alloc(struct vhost_virtqueue
*vq
, bool zcopy
)
237 struct vhost_net_ubuf_ref
*ubufs
;
238 /* No zero copy backend? Nothing to count. */
241 ubufs
= kmalloc(sizeof(*ubufs
), GFP_KERNEL
);
243 return ERR_PTR(-ENOMEM
);
244 atomic_set(&ubufs
->refcount
, 1);
245 init_waitqueue_head(&ubufs
->wait
);
250 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref
*ubufs
)
252 int r
= atomic_sub_return(1, &ubufs
->refcount
);
254 wake_up(&ubufs
->wait
);
258 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref
*ubufs
)
260 vhost_net_ubuf_put(ubufs
);
261 wait_event(ubufs
->wait
, !atomic_read(&ubufs
->refcount
));
264 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref
*ubufs
)
266 vhost_net_ubuf_put_and_wait(ubufs
);
270 static void vhost_net_clear_ubuf_info(struct vhost_net
*n
)
274 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
275 kfree(n
->vqs
[i
].ubuf_info
);
276 n
->vqs
[i
].ubuf_info
= NULL
;
280 static int vhost_net_set_ubuf_info(struct vhost_net
*n
)
285 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
286 zcopy
= vhost_net_zcopy_mask
& (0x1 << i
);
289 n
->vqs
[i
].ubuf_info
=
290 kmalloc_array(UIO_MAXIOV
,
291 sizeof(*n
->vqs
[i
].ubuf_info
),
293 if (!n
->vqs
[i
].ubuf_info
)
299 vhost_net_clear_ubuf_info(n
);
303 static void vhost_net_vq_reset(struct vhost_net
*n
)
307 vhost_net_clear_ubuf_info(n
);
309 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
310 n
->vqs
[i
].done_idx
= 0;
311 n
->vqs
[i
].upend_idx
= 0;
312 n
->vqs
[i
].ubufs
= NULL
;
313 n
->vqs
[i
].vhost_hlen
= 0;
314 n
->vqs
[i
].sock_hlen
= 0;
315 vhost_net_buf_init(&n
->vqs
[i
].rxq
);
320 static void vhost_net_tx_packet(struct vhost_net
*net
)
323 if (net
->tx_packets
< 1024)
326 net
->tx_zcopy_err
= 0;
329 static void vhost_net_tx_err(struct vhost_net
*net
)
334 static bool vhost_net_tx_select_zcopy(struct vhost_net
*net
)
336 /* TX flush waits for outstanding DMAs to be done.
337 * Don't start new DMAs.
339 return !net
->tx_flush
&&
340 net
->tx_packets
/ 64 >= net
->tx_zcopy_err
;
343 static bool vhost_sock_zcopy(struct socket
*sock
)
345 return unlikely(experimental_zcopytx
) &&
346 sock_flag(sock
->sk
, SOCK_ZEROCOPY
);
349 static bool vhost_sock_xdp(struct socket
*sock
)
351 return sock_flag(sock
->sk
, SOCK_XDP
);
354 /* In case of DMA done not in order in lower device driver for some reason.
355 * upend_idx is used to track end of used idx, done_idx is used to track head
356 * of used idx. Once lower device DMA done contiguously, we will signal KVM
359 static void vhost_zerocopy_signal_used(struct vhost_net
*net
,
360 struct vhost_virtqueue
*vq
)
362 struct vhost_net_virtqueue
*nvq
=
363 container_of(vq
, struct vhost_net_virtqueue
, vq
);
367 for (i
= nvq
->done_idx
; i
!= nvq
->upend_idx
; i
= (i
+ 1) % UIO_MAXIOV
) {
368 if (vq
->heads
[i
].len
== VHOST_DMA_FAILED_LEN
)
369 vhost_net_tx_err(net
);
370 if (VHOST_DMA_IS_DONE(vq
->heads
[i
].len
)) {
371 vq
->heads
[i
].len
= VHOST_DMA_CLEAR_LEN
;
377 add
= min(UIO_MAXIOV
- nvq
->done_idx
, j
);
378 vhost_add_used_and_signal_n(vq
->dev
, vq
,
379 &vq
->heads
[nvq
->done_idx
], add
);
380 nvq
->done_idx
= (nvq
->done_idx
+ add
) % UIO_MAXIOV
;
385 static void vhost_zerocopy_callback(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 (!vq
->private_data
)
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
= vq
->private_data
;
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");
483 vhost_net_signal_used(nvq
);
484 nvq
->batched_xdp
= 0;
487 static int sock_has_rx_data(struct socket
*sock
)
492 if (sock
->ops
->peek_len
)
493 return sock
->ops
->peek_len(sock
);
495 return skb_queue_empty(&sock
->sk
->sk_receive_queue
);
498 static void vhost_net_busy_poll_try_queue(struct vhost_net
*net
,
499 struct vhost_virtqueue
*vq
)
501 if (!vhost_vq_avail_empty(&net
->dev
, vq
)) {
502 vhost_poll_queue(&vq
->poll
);
503 } else if (unlikely(vhost_enable_notify(&net
->dev
, vq
))) {
504 vhost_disable_notify(&net
->dev
, vq
);
505 vhost_poll_queue(&vq
->poll
);
509 static void vhost_net_busy_poll(struct vhost_net
*net
,
510 struct vhost_virtqueue
*rvq
,
511 struct vhost_virtqueue
*tvq
,
515 unsigned long busyloop_timeout
;
516 unsigned long endtime
;
518 struct vhost_virtqueue
*vq
= poll_rx
? tvq
: rvq
;
520 /* Try to hold the vq mutex of the paired virtqueue. We can't
521 * use mutex_lock() here since we could not guarantee a
522 * consistenet lock ordering.
524 if (!mutex_trylock(&vq
->mutex
))
527 vhost_disable_notify(&net
->dev
, vq
);
528 sock
= rvq
->private_data
;
530 busyloop_timeout
= poll_rx
? rvq
->busyloop_timeout
:
531 tvq
->busyloop_timeout
;
534 endtime
= busy_clock() + busyloop_timeout
;
536 while (vhost_can_busy_poll(endtime
)) {
537 if (vhost_has_work(&net
->dev
)) {
538 *busyloop_intr
= true;
542 if ((sock_has_rx_data(sock
) &&
543 !vhost_vq_avail_empty(&net
->dev
, rvq
)) ||
544 !vhost_vq_avail_empty(&net
->dev
, tvq
))
552 if (poll_rx
|| sock_has_rx_data(sock
))
553 vhost_net_busy_poll_try_queue(net
, vq
);
554 else if (!poll_rx
) /* On tx here, sock has no rx data. */
555 vhost_enable_notify(&net
->dev
, rvq
);
557 mutex_unlock(&vq
->mutex
);
560 static int vhost_net_tx_get_vq_desc(struct vhost_net
*net
,
561 struct vhost_net_virtqueue
*tnvq
,
562 unsigned int *out_num
, unsigned int *in_num
,
563 struct msghdr
*msghdr
, bool *busyloop_intr
)
565 struct vhost_net_virtqueue
*rnvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
566 struct vhost_virtqueue
*rvq
= &rnvq
->vq
;
567 struct vhost_virtqueue
*tvq
= &tnvq
->vq
;
569 int r
= vhost_get_vq_desc(tvq
, tvq
->iov
, ARRAY_SIZE(tvq
->iov
),
570 out_num
, in_num
, NULL
, NULL
);
572 if (r
== tvq
->num
&& tvq
->busyloop_timeout
) {
573 /* Flush batched packets first */
574 if (!vhost_sock_zcopy(tvq
->private_data
))
575 vhost_tx_batch(net
, tnvq
, tvq
->private_data
, msghdr
);
577 vhost_net_busy_poll(net
, rvq
, tvq
, busyloop_intr
, false);
579 r
= vhost_get_vq_desc(tvq
, tvq
->iov
, ARRAY_SIZE(tvq
->iov
),
580 out_num
, in_num
, NULL
, NULL
);
586 static bool vhost_exceeds_maxpend(struct vhost_net
*net
)
588 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
589 struct vhost_virtqueue
*vq
= &nvq
->vq
;
591 return (nvq
->upend_idx
+ UIO_MAXIOV
- nvq
->done_idx
) % UIO_MAXIOV
>
592 min_t(unsigned int, VHOST_MAX_PEND
, vq
->num
>> 2);
595 static size_t init_iov_iter(struct vhost_virtqueue
*vq
, struct iov_iter
*iter
,
596 size_t hdr_size
, int out
)
598 /* Skip header. TODO: support TSO. */
599 size_t len
= iov_length(vq
->iov
, out
);
601 iov_iter_init(iter
, WRITE
, vq
->iov
, out
, len
);
602 iov_iter_advance(iter
, hdr_size
);
604 return iov_iter_count(iter
);
607 static bool vhost_exceeds_weight(int pkts
, int total_len
)
609 return total_len
>= VHOST_NET_WEIGHT
||
610 pkts
>= VHOST_NET_PKT_WEIGHT
;
613 static int get_tx_bufs(struct vhost_net
*net
,
614 struct vhost_net_virtqueue
*nvq
,
616 unsigned int *out
, unsigned int *in
,
617 size_t *len
, bool *busyloop_intr
)
619 struct vhost_virtqueue
*vq
= &nvq
->vq
;
622 ret
= vhost_net_tx_get_vq_desc(net
, nvq
, out
, in
, msg
, busyloop_intr
);
624 if (ret
< 0 || ret
== vq
->num
)
628 vq_err(vq
, "Unexpected descriptor format for TX: out %d, int %d\n",
634 *len
= init_iov_iter(vq
, &msg
->msg_iter
, nvq
->vhost_hlen
, *out
);
636 vq_err(vq
, "Unexpected header len for TX: %zd expected %zd\n",
637 *len
, nvq
->vhost_hlen
);
644 static bool tx_can_batch(struct vhost_virtqueue
*vq
, size_t total_len
)
646 return total_len
< VHOST_NET_WEIGHT
&&
647 !vhost_vq_avail_empty(vq
->dev
, vq
);
650 #define SKB_FRAG_PAGE_ORDER get_order(32768)
652 static bool vhost_net_page_frag_refill(struct vhost_net
*net
, unsigned int sz
,
653 struct page_frag
*pfrag
, gfp_t gfp
)
656 if (pfrag
->offset
+ sz
<= pfrag
->size
)
658 __page_frag_cache_drain(pfrag
->page
, net
->refcnt_bias
);
662 net
->refcnt_bias
= 0;
663 if (SKB_FRAG_PAGE_ORDER
) {
664 /* Avoid direct reclaim but allow kswapd to wake */
665 pfrag
->page
= alloc_pages((gfp
& ~__GFP_DIRECT_RECLAIM
) |
666 __GFP_COMP
| __GFP_NOWARN
|
668 SKB_FRAG_PAGE_ORDER
);
669 if (likely(pfrag
->page
)) {
670 pfrag
->size
= PAGE_SIZE
<< SKB_FRAG_PAGE_ORDER
;
674 pfrag
->page
= alloc_page(gfp
);
675 if (likely(pfrag
->page
)) {
676 pfrag
->size
= PAGE_SIZE
;
682 net
->refcnt_bias
= USHRT_MAX
;
683 page_ref_add(pfrag
->page
, USHRT_MAX
- 1);
687 #define VHOST_NET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
689 static int vhost_net_build_xdp(struct vhost_net_virtqueue
*nvq
,
690 struct iov_iter
*from
)
692 struct vhost_virtqueue
*vq
= &nvq
->vq
;
693 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
,
695 struct socket
*sock
= vq
->private_data
;
696 struct page_frag
*alloc_frag
= &net
->page_frag
;
697 struct virtio_net_hdr
*gso
;
698 struct xdp_buff
*xdp
= &nvq
->xdp
[nvq
->batched_xdp
];
699 struct tun_xdp_hdr
*hdr
;
700 size_t len
= iov_iter_count(from
);
701 int headroom
= vhost_sock_xdp(sock
) ? XDP_PACKET_HEADROOM
: 0;
702 int buflen
= SKB_DATA_ALIGN(sizeof(struct skb_shared_info
));
703 int pad
= SKB_DATA_ALIGN(VHOST_NET_RX_PAD
+ headroom
+ nvq
->sock_hlen
);
704 int sock_hlen
= nvq
->sock_hlen
;
708 if (unlikely(len
< nvq
->sock_hlen
))
711 if (SKB_DATA_ALIGN(len
+ pad
) +
712 SKB_DATA_ALIGN(sizeof(struct skb_shared_info
)) > PAGE_SIZE
)
715 buflen
+= SKB_DATA_ALIGN(len
+ pad
);
716 alloc_frag
->offset
= ALIGN((u64
)alloc_frag
->offset
, SMP_CACHE_BYTES
);
717 if (unlikely(!vhost_net_page_frag_refill(net
, buflen
,
718 alloc_frag
, GFP_KERNEL
)))
721 buf
= (char *)page_address(alloc_frag
->page
) + alloc_frag
->offset
;
722 copied
= copy_page_from_iter(alloc_frag
->page
,
724 offsetof(struct tun_xdp_hdr
, gso
),
726 if (copied
!= sock_hlen
)
732 if ((gso
->flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
733 vhost16_to_cpu(vq
, gso
->csum_start
) +
734 vhost16_to_cpu(vq
, gso
->csum_offset
) + 2 >
735 vhost16_to_cpu(vq
, gso
->hdr_len
)) {
736 gso
->hdr_len
= cpu_to_vhost16(vq
,
737 vhost16_to_cpu(vq
, gso
->csum_start
) +
738 vhost16_to_cpu(vq
, gso
->csum_offset
) + 2);
740 if (vhost16_to_cpu(vq
, gso
->hdr_len
) > len
)
745 copied
= copy_page_from_iter(alloc_frag
->page
,
746 alloc_frag
->offset
+ pad
,
751 xdp
->data_hard_start
= buf
;
752 xdp
->data
= buf
+ pad
;
753 xdp
->data_end
= xdp
->data
+ len
;
754 hdr
->buflen
= buflen
;
757 alloc_frag
->offset
+= buflen
;
764 static void handle_tx_copy(struct vhost_net
*net
, struct socket
*sock
)
766 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
767 struct vhost_virtqueue
*vq
= &nvq
->vq
;
770 struct msghdr msg
= {
775 .msg_flags
= MSG_DONTWAIT
,
777 size_t len
, total_len
= 0;
780 bool sock_can_batch
= (sock
->sk
->sk_sndbuf
== INT_MAX
);
783 bool busyloop_intr
= false;
785 if (nvq
->done_idx
== VHOST_NET_BATCH
)
786 vhost_tx_batch(net
, nvq
, sock
, &msg
);
788 head
= get_tx_bufs(net
, nvq
, &msg
, &out
, &in
, &len
,
790 /* On error, stop handling until the next kick. */
791 if (unlikely(head
< 0))
793 /* Nothing new? Wait for eventfd to tell us they refilled. */
794 if (head
== vq
->num
) {
795 if (unlikely(busyloop_intr
)) {
796 vhost_poll_queue(&vq
->poll
);
797 } else if (unlikely(vhost_enable_notify(&net
->dev
,
799 vhost_disable_notify(&net
->dev
, vq
);
807 /* For simplicity, TX batching is only enabled if
808 * sndbuf is unlimited.
810 if (sock_can_batch
) {
811 err
= vhost_net_build_xdp(nvq
, &msg
.msg_iter
);
814 } else if (unlikely(err
!= -ENOSPC
)) {
815 vhost_tx_batch(net
, nvq
, sock
, &msg
);
816 vhost_discard_vq_desc(vq
, 1);
817 vhost_net_enable_vq(net
, vq
);
821 /* We can't build XDP buff, go for single
822 * packet path but let's flush batched
825 vhost_tx_batch(net
, nvq
, sock
, &msg
);
826 msg
.msg_control
= NULL
;
828 if (tx_can_batch(vq
, total_len
))
829 msg
.msg_flags
|= MSG_MORE
;
831 msg
.msg_flags
&= ~MSG_MORE
;
834 /* TODO: Check specific error and bomb out unless ENOBUFS? */
835 err
= sock
->ops
->sendmsg(sock
, &msg
, len
);
836 if (unlikely(err
< 0)) {
837 vhost_discard_vq_desc(vq
, 1);
838 vhost_net_enable_vq(net
, vq
);
842 pr_debug("Truncated TX packet: len %d != %zd\n",
845 vq
->heads
[nvq
->done_idx
].id
= cpu_to_vhost32(vq
, head
);
846 vq
->heads
[nvq
->done_idx
].len
= 0;
848 if (vhost_exceeds_weight(++sent_pkts
, total_len
)) {
849 vhost_poll_queue(&vq
->poll
);
854 vhost_tx_batch(net
, nvq
, sock
, &msg
);
857 static void handle_tx_zerocopy(struct vhost_net
*net
, struct socket
*sock
)
859 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
860 struct vhost_virtqueue
*vq
= &nvq
->vq
;
863 struct msghdr msg
= {
868 .msg_flags
= MSG_DONTWAIT
,
870 struct tun_msg_ctl ctl
;
871 size_t len
, total_len
= 0;
873 struct vhost_net_ubuf_ref
*uninitialized_var(ubufs
);
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 struct ubuf_info
*ubuf
;
907 ubuf
= nvq
->ubuf_info
+ nvq
->upend_idx
;
909 vq
->heads
[nvq
->upend_idx
].id
= cpu_to_vhost32(vq
, head
);
910 vq
->heads
[nvq
->upend_idx
].len
= VHOST_DMA_IN_PROGRESS
;
911 ubuf
->callback
= vhost_zerocopy_callback
;
912 ubuf
->ctx
= nvq
->ubufs
;
913 ubuf
->desc
= nvq
->upend_idx
;
914 refcount_set(&ubuf
->refcnt
, 1);
915 msg
.msg_control
= &ctl
;
916 ctl
.type
= TUN_MSG_UBUF
;
918 msg
.msg_controllen
= sizeof(ctl
);
920 atomic_inc(&ubufs
->refcount
);
921 nvq
->upend_idx
= (nvq
->upend_idx
+ 1) % UIO_MAXIOV
;
923 msg
.msg_control
= NULL
;
927 if (tx_can_batch(vq
, total_len
) &&
928 likely(!vhost_exceeds_maxpend(net
))) {
929 msg
.msg_flags
|= MSG_MORE
;
931 msg
.msg_flags
&= ~MSG_MORE
;
934 /* TODO: Check specific error and bomb out unless ENOBUFS? */
935 err
= sock
->ops
->sendmsg(sock
, &msg
, len
);
936 if (unlikely(err
< 0)) {
938 vhost_net_ubuf_put(ubufs
);
939 nvq
->upend_idx
= ((unsigned)nvq
->upend_idx
- 1)
942 vhost_discard_vq_desc(vq
, 1);
943 vhost_net_enable_vq(net
, vq
);
947 pr_debug("Truncated TX packet: "
948 " len %d != %zd\n", err
, len
);
950 vhost_add_used_and_signal(&net
->dev
, vq
, head
, 0);
952 vhost_zerocopy_signal_used(net
, vq
);
953 vhost_net_tx_packet(net
);
954 if (unlikely(vhost_exceeds_weight(++sent_pkts
, total_len
))) {
955 vhost_poll_queue(&vq
->poll
);
961 /* Expects to be always run from workqueue - which acts as
962 * read-size critical section for our kind of RCU. */
963 static void handle_tx(struct vhost_net
*net
)
965 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
966 struct vhost_virtqueue
*vq
= &nvq
->vq
;
969 mutex_lock_nested(&vq
->mutex
, VHOST_NET_VQ_TX
);
970 sock
= vq
->private_data
;
974 if (!vq_iotlb_prefetch(vq
))
977 vhost_disable_notify(&net
->dev
, vq
);
978 vhost_net_disable_vq(net
, vq
);
980 if (vhost_sock_zcopy(sock
))
981 handle_tx_zerocopy(net
, sock
);
983 handle_tx_copy(net
, sock
);
986 mutex_unlock(&vq
->mutex
);
989 static int peek_head_len(struct vhost_net_virtqueue
*rvq
, struct sock
*sk
)
991 struct sk_buff
*head
;
996 return vhost_net_buf_peek(rvq
);
998 spin_lock_irqsave(&sk
->sk_receive_queue
.lock
, flags
);
999 head
= skb_peek(&sk
->sk_receive_queue
);
1002 if (skb_vlan_tag_present(head
))
1006 spin_unlock_irqrestore(&sk
->sk_receive_queue
.lock
, flags
);
1010 static int vhost_net_rx_peek_head_len(struct vhost_net
*net
, struct sock
*sk
,
1011 bool *busyloop_intr
)
1013 struct vhost_net_virtqueue
*rnvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
1014 struct vhost_net_virtqueue
*tnvq
= &net
->vqs
[VHOST_NET_VQ_TX
];
1015 struct vhost_virtqueue
*rvq
= &rnvq
->vq
;
1016 struct vhost_virtqueue
*tvq
= &tnvq
->vq
;
1017 int len
= peek_head_len(rnvq
, sk
);
1019 if (!len
&& rvq
->busyloop_timeout
) {
1020 /* Flush batched heads first */
1021 vhost_net_signal_used(rnvq
);
1022 /* Both tx vq and rx socket were polled here */
1023 vhost_net_busy_poll(net
, rvq
, tvq
, busyloop_intr
, true);
1025 len
= peek_head_len(rnvq
, sk
);
1031 /* This is a multi-buffer version of vhost_get_desc, that works if
1032 * vq has read descriptors only.
1033 * @vq - the relevant virtqueue
1034 * @datalen - data length we'll be reading
1035 * @iovcount - returned count of io vectors we fill
1037 * @log_num - log offset
1038 * @quota - headcount quota, 1 for big buffer
1039 * returns number of buffer heads allocated, negative on error
1041 static int get_rx_bufs(struct vhost_virtqueue
*vq
,
1042 struct vring_used_elem
*heads
,
1045 struct vhost_log
*log
,
1049 unsigned int out
, in
;
1054 /* len is always initialized before use since we are always called with
1057 u32
uninitialized_var(len
);
1059 while (datalen
> 0 && headcount
< quota
) {
1060 if (unlikely(seg
>= UIO_MAXIOV
)) {
1064 r
= vhost_get_vq_desc(vq
, vq
->iov
+ seg
,
1065 ARRAY_SIZE(vq
->iov
) - seg
, &out
,
1067 if (unlikely(r
< 0))
1075 if (unlikely(out
|| in
<= 0)) {
1076 vq_err(vq
, "unexpected descriptor format for RX: "
1077 "out %d, in %d\n", out
, in
);
1081 if (unlikely(log
)) {
1085 heads
[headcount
].id
= cpu_to_vhost32(vq
, d
);
1086 len
= iov_length(vq
->iov
+ seg
, in
);
1087 heads
[headcount
].len
= cpu_to_vhost32(vq
, len
);
1092 heads
[headcount
- 1].len
= cpu_to_vhost32(vq
, len
+ datalen
);
1097 /* Detect overrun */
1098 if (unlikely(datalen
> 0)) {
1104 vhost_discard_vq_desc(vq
, headcount
);
1108 /* Expects to be always run from workqueue - which acts as
1109 * read-size critical section for our kind of RCU. */
1110 static void handle_rx(struct vhost_net
*net
)
1112 struct vhost_net_virtqueue
*nvq
= &net
->vqs
[VHOST_NET_VQ_RX
];
1113 struct vhost_virtqueue
*vq
= &nvq
->vq
;
1114 unsigned uninitialized_var(in
), log
;
1115 struct vhost_log
*vq_log
;
1116 struct msghdr msg
= {
1119 .msg_control
= NULL
, /* FIXME: get and handle RX aux data. */
1120 .msg_controllen
= 0,
1121 .msg_flags
= MSG_DONTWAIT
,
1123 struct virtio_net_hdr hdr
= {
1125 .gso_type
= VIRTIO_NET_HDR_GSO_NONE
1127 size_t total_len
= 0;
1130 size_t vhost_hlen
, sock_hlen
;
1131 size_t vhost_len
, sock_len
;
1132 bool busyloop_intr
= false;
1133 struct socket
*sock
;
1134 struct iov_iter fixup
;
1135 __virtio16 num_buffers
;
1138 mutex_lock_nested(&vq
->mutex
, VHOST_NET_VQ_RX
);
1139 sock
= vq
->private_data
;
1143 if (!vq_iotlb_prefetch(vq
))
1146 vhost_disable_notify(&net
->dev
, vq
);
1147 vhost_net_disable_vq(net
, vq
);
1149 vhost_hlen
= nvq
->vhost_hlen
;
1150 sock_hlen
= nvq
->sock_hlen
;
1152 vq_log
= unlikely(vhost_has_feature(vq
, VHOST_F_LOG_ALL
)) ?
1154 mergeable
= vhost_has_feature(vq
, VIRTIO_NET_F_MRG_RXBUF
);
1156 while ((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
);
1240 total_len
+= vhost_len
;
1241 if (unlikely(vhost_exceeds_weight(++recv_pkts
, total_len
))) {
1242 vhost_poll_queue(&vq
->poll
);
1246 if (unlikely(busyloop_intr
))
1247 vhost_poll_queue(&vq
->poll
);
1249 vhost_net_enable_vq(net
, vq
);
1251 vhost_net_signal_used(nvq
);
1252 mutex_unlock(&vq
->mutex
);
1255 static void handle_tx_kick(struct vhost_work
*work
)
1257 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
1259 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
1264 static void handle_rx_kick(struct vhost_work
*work
)
1266 struct vhost_virtqueue
*vq
= container_of(work
, struct vhost_virtqueue
,
1268 struct vhost_net
*net
= container_of(vq
->dev
, struct vhost_net
, dev
);
1273 static void handle_tx_net(struct vhost_work
*work
)
1275 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
1276 poll
[VHOST_NET_VQ_TX
].work
);
1280 static void handle_rx_net(struct vhost_work
*work
)
1282 struct vhost_net
*net
= container_of(work
, struct vhost_net
,
1283 poll
[VHOST_NET_VQ_RX
].work
);
1287 static int vhost_net_open(struct inode
*inode
, struct file
*f
)
1289 struct vhost_net
*n
;
1290 struct vhost_dev
*dev
;
1291 struct vhost_virtqueue
**vqs
;
1293 struct xdp_buff
*xdp
;
1296 n
= kvmalloc(sizeof *n
, GFP_KERNEL
| __GFP_RETRY_MAYFAIL
);
1299 vqs
= kmalloc_array(VHOST_NET_VQ_MAX
, sizeof(*vqs
), GFP_KERNEL
);
1305 queue
= kmalloc_array(VHOST_NET_BATCH
, sizeof(void *),
1312 n
->vqs
[VHOST_NET_VQ_RX
].rxq
.queue
= queue
;
1314 xdp
= kmalloc_array(VHOST_NET_BATCH
, sizeof(*xdp
), GFP_KERNEL
);
1321 n
->vqs
[VHOST_NET_VQ_TX
].xdp
= xdp
;
1324 vqs
[VHOST_NET_VQ_TX
] = &n
->vqs
[VHOST_NET_VQ_TX
].vq
;
1325 vqs
[VHOST_NET_VQ_RX
] = &n
->vqs
[VHOST_NET_VQ_RX
].vq
;
1326 n
->vqs
[VHOST_NET_VQ_TX
].vq
.handle_kick
= handle_tx_kick
;
1327 n
->vqs
[VHOST_NET_VQ_RX
].vq
.handle_kick
= handle_rx_kick
;
1328 for (i
= 0; i
< VHOST_NET_VQ_MAX
; i
++) {
1329 n
->vqs
[i
].ubufs
= NULL
;
1330 n
->vqs
[i
].ubuf_info
= NULL
;
1331 n
->vqs
[i
].upend_idx
= 0;
1332 n
->vqs
[i
].done_idx
= 0;
1333 n
->vqs
[i
].batched_xdp
= 0;
1334 n
->vqs
[i
].vhost_hlen
= 0;
1335 n
->vqs
[i
].sock_hlen
= 0;
1336 n
->vqs
[i
].rx_ring
= NULL
;
1337 vhost_net_buf_init(&n
->vqs
[i
].rxq
);
1339 vhost_dev_init(dev
, vqs
, VHOST_NET_VQ_MAX
);
1341 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_TX
, handle_tx_net
, EPOLLOUT
, dev
);
1342 vhost_poll_init(n
->poll
+ VHOST_NET_VQ_RX
, handle_rx_net
, EPOLLIN
, dev
);
1344 f
->private_data
= n
;
1345 n
->page_frag
.page
= NULL
;
1351 static struct socket
*vhost_net_stop_vq(struct vhost_net
*n
,
1352 struct vhost_virtqueue
*vq
)
1354 struct socket
*sock
;
1355 struct vhost_net_virtqueue
*nvq
=
1356 container_of(vq
, struct vhost_net_virtqueue
, vq
);
1358 mutex_lock(&vq
->mutex
);
1359 sock
= vq
->private_data
;
1360 vhost_net_disable_vq(n
, vq
);
1361 vq
->private_data
= NULL
;
1362 vhost_net_buf_unproduce(nvq
);
1363 nvq
->rx_ring
= NULL
;
1364 mutex_unlock(&vq
->mutex
);
1368 static void vhost_net_stop(struct vhost_net
*n
, struct socket
**tx_sock
,
1369 struct socket
**rx_sock
)
1371 *tx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_TX
].vq
);
1372 *rx_sock
= vhost_net_stop_vq(n
, &n
->vqs
[VHOST_NET_VQ_RX
].vq
);
1375 static void vhost_net_flush_vq(struct vhost_net
*n
, int index
)
1377 vhost_poll_flush(n
->poll
+ index
);
1378 vhost_poll_flush(&n
->vqs
[index
].vq
.poll
);
1381 static void vhost_net_flush(struct vhost_net
*n
)
1383 vhost_net_flush_vq(n
, VHOST_NET_VQ_TX
);
1384 vhost_net_flush_vq(n
, VHOST_NET_VQ_RX
);
1385 if (n
->vqs
[VHOST_NET_VQ_TX
].ubufs
) {
1386 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1388 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1389 /* Wait for all lower device DMAs done. */
1390 vhost_net_ubuf_put_and_wait(n
->vqs
[VHOST_NET_VQ_TX
].ubufs
);
1391 mutex_lock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1392 n
->tx_flush
= false;
1393 atomic_set(&n
->vqs
[VHOST_NET_VQ_TX
].ubufs
->refcount
, 1);
1394 mutex_unlock(&n
->vqs
[VHOST_NET_VQ_TX
].vq
.mutex
);
1398 static int vhost_net_release(struct inode
*inode
, struct file
*f
)
1400 struct vhost_net
*n
= f
->private_data
;
1401 struct socket
*tx_sock
;
1402 struct socket
*rx_sock
;
1404 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
1406 vhost_dev_stop(&n
->dev
);
1407 vhost_dev_cleanup(&n
->dev
);
1408 vhost_net_vq_reset(n
);
1410 sockfd_put(tx_sock
);
1412 sockfd_put(rx_sock
);
1413 /* Make sure no callbacks are outstanding */
1415 /* We do an extra flush before freeing memory,
1416 * since jobs can re-queue themselves. */
1418 kfree(n
->vqs
[VHOST_NET_VQ_RX
].rxq
.queue
);
1419 kfree(n
->vqs
[VHOST_NET_VQ_TX
].xdp
);
1421 if (n
->page_frag
.page
)
1422 __page_frag_cache_drain(n
->page_frag
.page
, n
->refcnt_bias
);
1427 static struct socket
*get_raw_socket(int fd
)
1430 struct sockaddr_ll sa
;
1431 char buf
[MAX_ADDR_LEN
];
1434 struct socket
*sock
= sockfd_lookup(fd
, &r
);
1437 return ERR_PTR(-ENOTSOCK
);
1439 /* Parameter checking */
1440 if (sock
->sk
->sk_type
!= SOCK_RAW
) {
1441 r
= -ESOCKTNOSUPPORT
;
1445 r
= sock
->ops
->getname(sock
, (struct sockaddr
*)&uaddr
.sa
, 0);
1449 if (uaddr
.sa
.sll_family
!= AF_PACKET
) {
1459 static struct ptr_ring
*get_tap_ptr_ring(int fd
)
1461 struct ptr_ring
*ring
;
1462 struct file
*file
= fget(fd
);
1466 ring
= tun_get_tx_ring(file
);
1469 ring
= tap_get_ptr_ring(file
);
1478 static struct socket
*get_tap_socket(int fd
)
1480 struct file
*file
= fget(fd
);
1481 struct socket
*sock
;
1484 return ERR_PTR(-EBADF
);
1485 sock
= tun_get_socket(file
);
1488 sock
= tap_get_socket(file
);
1494 static struct socket
*get_socket(int fd
)
1496 struct socket
*sock
;
1498 /* special case to disable backend */
1501 sock
= get_raw_socket(fd
);
1504 sock
= get_tap_socket(fd
);
1507 return ERR_PTR(-ENOTSOCK
);
1510 static long vhost_net_set_backend(struct vhost_net
*n
, unsigned index
, int fd
)
1512 struct socket
*sock
, *oldsock
;
1513 struct vhost_virtqueue
*vq
;
1514 struct vhost_net_virtqueue
*nvq
;
1515 struct vhost_net_ubuf_ref
*ubufs
, *oldubufs
= NULL
;
1518 mutex_lock(&n
->dev
.mutex
);
1519 r
= vhost_dev_check_owner(&n
->dev
);
1523 if (index
>= VHOST_NET_VQ_MAX
) {
1527 vq
= &n
->vqs
[index
].vq
;
1528 nvq
= &n
->vqs
[index
];
1529 mutex_lock(&vq
->mutex
);
1531 /* Verify that ring has been setup correctly. */
1532 if (!vhost_vq_access_ok(vq
)) {
1536 sock
= get_socket(fd
);
1542 /* start polling new socket */
1543 oldsock
= vq
->private_data
;
1544 if (sock
!= oldsock
) {
1545 ubufs
= vhost_net_ubuf_alloc(vq
,
1546 sock
&& vhost_sock_zcopy(sock
));
1547 if (IS_ERR(ubufs
)) {
1552 vhost_net_disable_vq(n
, vq
);
1553 vq
->private_data
= sock
;
1554 vhost_net_buf_unproduce(nvq
);
1555 r
= vhost_vq_init_access(vq
);
1558 r
= vhost_net_enable_vq(n
, vq
);
1561 if (index
== VHOST_NET_VQ_RX
)
1562 nvq
->rx_ring
= get_tap_ptr_ring(fd
);
1564 oldubufs
= nvq
->ubufs
;
1568 n
->tx_zcopy_err
= 0;
1569 n
->tx_flush
= false;
1572 mutex_unlock(&vq
->mutex
);
1575 vhost_net_ubuf_put_wait_and_free(oldubufs
);
1576 mutex_lock(&vq
->mutex
);
1577 vhost_zerocopy_signal_used(n
, vq
);
1578 mutex_unlock(&vq
->mutex
);
1582 vhost_net_flush_vq(n
, index
);
1583 sockfd_put(oldsock
);
1586 mutex_unlock(&n
->dev
.mutex
);
1590 vq
->private_data
= oldsock
;
1591 vhost_net_enable_vq(n
, vq
);
1593 vhost_net_ubuf_put_wait_and_free(ubufs
);
1598 mutex_unlock(&vq
->mutex
);
1600 mutex_unlock(&n
->dev
.mutex
);
1604 static long vhost_net_reset_owner(struct vhost_net
*n
)
1606 struct socket
*tx_sock
= NULL
;
1607 struct socket
*rx_sock
= NULL
;
1609 struct vhost_umem
*umem
;
1611 mutex_lock(&n
->dev
.mutex
);
1612 err
= vhost_dev_check_owner(&n
->dev
);
1615 umem
= vhost_dev_reset_owner_prepare();
1620 vhost_net_stop(n
, &tx_sock
, &rx_sock
);
1622 vhost_dev_stop(&n
->dev
);
1623 vhost_dev_reset_owner(&n
->dev
, umem
);
1624 vhost_net_vq_reset(n
);
1626 mutex_unlock(&n
->dev
.mutex
);
1628 sockfd_put(tx_sock
);
1630 sockfd_put(rx_sock
);
1634 static int vhost_net_set_backend_features(struct vhost_net
*n
, u64 features
)
1638 mutex_lock(&n
->dev
.mutex
);
1639 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
1640 mutex_lock(&n
->vqs
[i
].vq
.mutex
);
1641 n
->vqs
[i
].vq
.acked_backend_features
= features
;
1642 mutex_unlock(&n
->vqs
[i
].vq
.mutex
);
1644 mutex_unlock(&n
->dev
.mutex
);
1649 static int vhost_net_set_features(struct vhost_net
*n
, u64 features
)
1651 size_t vhost_hlen
, sock_hlen
, hdr_len
;
1654 hdr_len
= (features
& ((1ULL << VIRTIO_NET_F_MRG_RXBUF
) |
1655 (1ULL << VIRTIO_F_VERSION_1
))) ?
1656 sizeof(struct virtio_net_hdr_mrg_rxbuf
) :
1657 sizeof(struct virtio_net_hdr
);
1658 if (features
& (1 << VHOST_NET_F_VIRTIO_NET_HDR
)) {
1659 /* vhost provides vnet_hdr */
1660 vhost_hlen
= hdr_len
;
1663 /* socket provides vnet_hdr */
1665 sock_hlen
= hdr_len
;
1667 mutex_lock(&n
->dev
.mutex
);
1668 if ((features
& (1 << VHOST_F_LOG_ALL
)) &&
1669 !vhost_log_access_ok(&n
->dev
))
1672 if ((features
& (1ULL << VIRTIO_F_IOMMU_PLATFORM
))) {
1673 if (vhost_init_device_iotlb(&n
->dev
, true))
1677 for (i
= 0; i
< VHOST_NET_VQ_MAX
; ++i
) {
1678 mutex_lock(&n
->vqs
[i
].vq
.mutex
);
1679 n
->vqs
[i
].vq
.acked_features
= features
;
1680 n
->vqs
[i
].vhost_hlen
= vhost_hlen
;
1681 n
->vqs
[i
].sock_hlen
= sock_hlen
;
1682 mutex_unlock(&n
->vqs
[i
].vq
.mutex
);
1684 mutex_unlock(&n
->dev
.mutex
);
1688 mutex_unlock(&n
->dev
.mutex
);
1692 static long vhost_net_set_owner(struct vhost_net
*n
)
1696 mutex_lock(&n
->dev
.mutex
);
1697 if (vhost_dev_has_owner(&n
->dev
)) {
1701 r
= vhost_net_set_ubuf_info(n
);
1704 r
= vhost_dev_set_owner(&n
->dev
);
1706 vhost_net_clear_ubuf_info(n
);
1709 mutex_unlock(&n
->dev
.mutex
);
1713 static long vhost_net_ioctl(struct file
*f
, unsigned int ioctl
,
1716 struct vhost_net
*n
= f
->private_data
;
1717 void __user
*argp
= (void __user
*)arg
;
1718 u64 __user
*featurep
= argp
;
1719 struct vhost_vring_file backend
;
1724 case VHOST_NET_SET_BACKEND
:
1725 if (copy_from_user(&backend
, argp
, sizeof backend
))
1727 return vhost_net_set_backend(n
, backend
.index
, backend
.fd
);
1728 case VHOST_GET_FEATURES
:
1729 features
= VHOST_NET_FEATURES
;
1730 if (copy_to_user(featurep
, &features
, sizeof features
))
1733 case VHOST_SET_FEATURES
:
1734 if (copy_from_user(&features
, featurep
, sizeof features
))
1736 if (features
& ~VHOST_NET_FEATURES
)
1738 return vhost_net_set_features(n
, features
);
1739 case VHOST_GET_BACKEND_FEATURES
:
1740 features
= VHOST_NET_BACKEND_FEATURES
;
1741 if (copy_to_user(featurep
, &features
, sizeof(features
)))
1744 case VHOST_SET_BACKEND_FEATURES
:
1745 if (copy_from_user(&features
, featurep
, sizeof(features
)))
1747 if (features
& ~VHOST_NET_BACKEND_FEATURES
)
1749 return vhost_net_set_backend_features(n
, features
);
1750 case VHOST_RESET_OWNER
:
1751 return vhost_net_reset_owner(n
);
1752 case VHOST_SET_OWNER
:
1753 return vhost_net_set_owner(n
);
1755 mutex_lock(&n
->dev
.mutex
);
1756 r
= vhost_dev_ioctl(&n
->dev
, ioctl
, argp
);
1757 if (r
== -ENOIOCTLCMD
)
1758 r
= vhost_vring_ioctl(&n
->dev
, ioctl
, argp
);
1761 mutex_unlock(&n
->dev
.mutex
);
1766 #ifdef CONFIG_COMPAT
1767 static long vhost_net_compat_ioctl(struct file
*f
, unsigned int ioctl
,
1770 return vhost_net_ioctl(f
, ioctl
, (unsigned long)compat_ptr(arg
));
1774 static ssize_t
vhost_net_chr_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
1776 struct file
*file
= iocb
->ki_filp
;
1777 struct vhost_net
*n
= file
->private_data
;
1778 struct vhost_dev
*dev
= &n
->dev
;
1779 int noblock
= file
->f_flags
& O_NONBLOCK
;
1781 return vhost_chr_read_iter(dev
, to
, noblock
);
1784 static ssize_t
vhost_net_chr_write_iter(struct kiocb
*iocb
,
1785 struct iov_iter
*from
)
1787 struct file
*file
= iocb
->ki_filp
;
1788 struct vhost_net
*n
= file
->private_data
;
1789 struct vhost_dev
*dev
= &n
->dev
;
1791 return vhost_chr_write_iter(dev
, from
);
1794 static __poll_t
vhost_net_chr_poll(struct file
*file
, poll_table
*wait
)
1796 struct vhost_net
*n
= file
->private_data
;
1797 struct vhost_dev
*dev
= &n
->dev
;
1799 return vhost_chr_poll(file
, dev
, wait
);
1802 static const struct file_operations vhost_net_fops
= {
1803 .owner
= THIS_MODULE
,
1804 .release
= vhost_net_release
,
1805 .read_iter
= vhost_net_chr_read_iter
,
1806 .write_iter
= vhost_net_chr_write_iter
,
1807 .poll
= vhost_net_chr_poll
,
1808 .unlocked_ioctl
= vhost_net_ioctl
,
1809 #ifdef CONFIG_COMPAT
1810 .compat_ioctl
= vhost_net_compat_ioctl
,
1812 .open
= vhost_net_open
,
1813 .llseek
= noop_llseek
,
1816 static struct miscdevice vhost_net_misc
= {
1817 .minor
= VHOST_NET_MINOR
,
1818 .name
= "vhost-net",
1819 .fops
= &vhost_net_fops
,
1822 static int vhost_net_init(void)
1824 if (experimental_zcopytx
)
1825 vhost_net_enable_zcopy(VHOST_NET_VQ_TX
);
1826 return misc_register(&vhost_net_misc
);
1828 module_init(vhost_net_init
);
1830 static void vhost_net_exit(void)
1832 misc_deregister(&vhost_net_misc
);
1834 module_exit(vhost_net_exit
);
1836 MODULE_VERSION("0.0.1");
1837 MODULE_LICENSE("GPL v2");
1838 MODULE_AUTHOR("Michael S. Tsirkin");
1839 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1840 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR
);
1841 MODULE_ALIAS("devname:vhost-net");