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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>
22
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>
32
33#include <net/sock.h>
34#include <net/xdp.h>
35
36#include "vhost.h"
37
38static int experimental_zcopytx = 0;
39module_param(experimental_zcopytx, int, 0444);
40MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
41 " 1 -Enable; 0 - Disable");
42
43
44
45#define VHOST_NET_WEIGHT 0x80000
46
47
48
49
50
51#define VHOST_NET_PKT_WEIGHT 256
52
53
54#define VHOST_MAX_PEND 128
55#define VHOST_GOODCOPY_LEN 256
56
57
58
59
60
61
62#define VHOST_DMA_FAILED_LEN ((__force __virtio32)3)
63
64#define VHOST_DMA_DONE_LEN ((__force __virtio32)2)
65
66#define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1)
67
68#define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0)
69
70#define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN)
71
72enum {
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)
77};
78
79enum {
80 VHOST_NET_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2)
81};
82
83enum {
84 VHOST_NET_VQ_RX = 0,
85 VHOST_NET_VQ_TX = 1,
86 VHOST_NET_VQ_MAX = 2,
87};
88
89struct vhost_net_ubuf_ref {
90
91
92
93
94
95 atomic_t refcount;
96 wait_queue_head_t wait;
97 struct vhost_virtqueue *vq;
98};
99
100#define VHOST_NET_BATCH 64
101struct vhost_net_buf {
102 void **queue;
103 int tail;
104 int head;
105};
106
107struct vhost_net_virtqueue {
108 struct vhost_virtqueue vq;
109 size_t vhost_hlen;
110 size_t sock_hlen;
111
112
113 int upend_idx;
114
115
116
117 int done_idx;
118
119 int batched_xdp;
120
121 struct ubuf_info *ubuf_info;
122
123
124 struct vhost_net_ubuf_ref *ubufs;
125 struct ptr_ring *rx_ring;
126 struct vhost_net_buf rxq;
127
128 struct xdp_buff *xdp;
129};
130
131struct vhost_net {
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
136
137 unsigned tx_packets;
138
139
140 unsigned tx_zcopy_err;
141
142 bool tx_flush;
143
144 struct page_frag page_frag;
145
146 int refcnt_bias;
147};
148
149static unsigned vhost_net_zcopy_mask __read_mostly;
150
151static void *vhost_net_buf_get_ptr(struct vhost_net_buf *rxq)
152{
153 if (rxq->tail != rxq->head)
154 return rxq->queue[rxq->head];
155 else
156 return NULL;
157}
158
159static int vhost_net_buf_get_size(struct vhost_net_buf *rxq)
160{
161 return rxq->tail - rxq->head;
162}
163
164static int vhost_net_buf_is_empty(struct vhost_net_buf *rxq)
165{
166 return rxq->tail == rxq->head;
167}
168
169static void *vhost_net_buf_consume(struct vhost_net_buf *rxq)
170{
171 void *ret = vhost_net_buf_get_ptr(rxq);
172 ++rxq->head;
173 return ret;
174}
175
176static int vhost_net_buf_produce(struct vhost_net_virtqueue *nvq)
177{
178 struct vhost_net_buf *rxq = &nvq->rxq;
179
180 rxq->head = 0;
181 rxq->tail = ptr_ring_consume_batched(nvq->rx_ring, rxq->queue,
182 VHOST_NET_BATCH);
183 return rxq->tail;
184}
185
186static void vhost_net_buf_unproduce(struct vhost_net_virtqueue *nvq)
187{
188 struct vhost_net_buf *rxq = &nvq->rxq;
189
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),
193 tun_ptr_free);
194 rxq->head = rxq->tail = 0;
195 }
196}
197
198static int vhost_net_buf_peek_len(void *ptr)
199{
200 if (tun_is_xdp_frame(ptr)) {
201 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
202
203 return xdpf->len;
204 }
205
206 return __skb_array_len_with_tag(ptr);
207}
208
209static int vhost_net_buf_peek(struct vhost_net_virtqueue *nvq)
210{
211 struct vhost_net_buf *rxq = &nvq->rxq;
212
213 if (!vhost_net_buf_is_empty(rxq))
214 goto out;
215
216 if (!vhost_net_buf_produce(nvq))
217 return 0;
218
219out:
220 return vhost_net_buf_peek_len(vhost_net_buf_get_ptr(rxq));
221}
222
223static void vhost_net_buf_init(struct vhost_net_buf *rxq)
224{
225 rxq->head = rxq->tail = 0;
226}
227
228static void vhost_net_enable_zcopy(int vq)
229{
230 vhost_net_zcopy_mask |= 0x1 << vq;
231}
232
233static struct vhost_net_ubuf_ref *
234vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy)
235{
236 struct vhost_net_ubuf_ref *ubufs;
237
238 if (!zcopy)
239 return NULL;
240 ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL);
241 if (!ubufs)
242 return ERR_PTR(-ENOMEM);
243 atomic_set(&ubufs->refcount, 1);
244 init_waitqueue_head(&ubufs->wait);
245 ubufs->vq = vq;
246 return ubufs;
247}
248
249static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
250{
251 int r = atomic_sub_return(1, &ubufs->refcount);
252 if (unlikely(!r))
253 wake_up(&ubufs->wait);
254 return r;
255}
256
257static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs)
258{
259 vhost_net_ubuf_put(ubufs);
260 wait_event(ubufs->wait, !atomic_read(&ubufs->refcount));
261}
262
263static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs)
264{
265 vhost_net_ubuf_put_and_wait(ubufs);
266 kfree(ubufs);
267}
268
269static void vhost_net_clear_ubuf_info(struct vhost_net *n)
270{
271 int i;
272
273 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
274 kfree(n->vqs[i].ubuf_info);
275 n->vqs[i].ubuf_info = NULL;
276 }
277}
278
279static int vhost_net_set_ubuf_info(struct vhost_net *n)
280{
281 bool zcopy;
282 int i;
283
284 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
285 zcopy = vhost_net_zcopy_mask & (0x1 << i);
286 if (!zcopy)
287 continue;
288 n->vqs[i].ubuf_info =
289 kmalloc_array(UIO_MAXIOV,
290 sizeof(*n->vqs[i].ubuf_info),
291 GFP_KERNEL);
292 if (!n->vqs[i].ubuf_info)
293 goto err;
294 }
295 return 0;
296
297err:
298 vhost_net_clear_ubuf_info(n);
299 return -ENOMEM;
300}
301
302static void vhost_net_vq_reset(struct vhost_net *n)
303{
304 int i;
305
306 vhost_net_clear_ubuf_info(n);
307
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);
315 }
316
317}
318
319static void vhost_net_tx_packet(struct vhost_net *net)
320{
321 ++net->tx_packets;
322 if (net->tx_packets < 1024)
323 return;
324 net->tx_packets = 0;
325 net->tx_zcopy_err = 0;
326}
327
328static void vhost_net_tx_err(struct vhost_net *net)
329{
330 ++net->tx_zcopy_err;
331}
332
333static bool vhost_net_tx_select_zcopy(struct vhost_net *net)
334{
335
336
337
338 return !net->tx_flush &&
339 net->tx_packets / 64 >= net->tx_zcopy_err;
340}
341
342static bool vhost_sock_zcopy(struct socket *sock)
343{
344 return unlikely(experimental_zcopytx) &&
345 sock_flag(sock->sk, SOCK_ZEROCOPY);
346}
347
348static bool vhost_sock_xdp(struct socket *sock)
349{
350 return sock_flag(sock->sk, SOCK_XDP);
351}
352
353
354
355
356
357
358static void vhost_zerocopy_signal_used(struct vhost_net *net,
359 struct vhost_virtqueue *vq)
360{
361 struct vhost_net_virtqueue *nvq =
362 container_of(vq, struct vhost_net_virtqueue, vq);
363 int i, add;
364 int j = 0;
365
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;
371 ++j;
372 } else
373 break;
374 }
375 while (j) {
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;
380 j -= add;
381 }
382}
383
384static void vhost_zerocopy_callback(struct sk_buff *skb,
385 struct ubuf_info *ubuf, bool success)
386{
387 struct vhost_net_ubuf_ref *ubufs = ubuf->ctx;
388 struct vhost_virtqueue *vq = ubufs->vq;
389 int cnt;
390
391 rcu_read_lock_bh();
392
393
394 vq->heads[ubuf->desc].len = success ?
395 VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;
396 cnt = vhost_net_ubuf_put(ubufs);
397
398
399
400
401
402
403
404
405 if (cnt <= 1 || !(cnt % 16))
406 vhost_poll_queue(&vq->poll);
407
408 rcu_read_unlock_bh();
409}
410
411static inline unsigned long busy_clock(void)
412{
413 return local_clock() >> 10;
414}
415
416static bool vhost_can_busy_poll(unsigned long endtime)
417{
418 return likely(!need_resched() && !time_after(busy_clock(), endtime) &&
419 !signal_pending(current));
420}
421
422static void vhost_net_disable_vq(struct vhost_net *n,
423 struct vhost_virtqueue *vq)
424{
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))
429 return;
430 vhost_poll_stop(poll);
431}
432
433static int vhost_net_enable_vq(struct vhost_net *n,
434 struct vhost_virtqueue *vq)
435{
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);
439 struct socket *sock;
440
441 sock = vhost_vq_get_backend(vq);
442 if (!sock)
443 return 0;
444
445 return vhost_poll_start(poll, sock->file);
446}
447
448static void vhost_net_signal_used(struct vhost_net_virtqueue *nvq)
449{
450 struct vhost_virtqueue *vq = &nvq->vq;
451 struct vhost_dev *dev = vq->dev;
452
453 if (!nvq->done_idx)
454 return;
455
456 vhost_add_used_and_signal_n(dev, vq, vq->heads, nvq->done_idx);
457 nvq->done_idx = 0;
458}
459
460static void vhost_tx_batch(struct vhost_net *net,
461 struct vhost_net_virtqueue *nvq,
462 struct socket *sock,
463 struct msghdr *msghdr)
464{
465 struct tun_msg_ctl ctl = {
466 .type = TUN_MSG_PTR,
467 .num = nvq->batched_xdp,
468 .ptr = nvq->xdp,
469 };
470 int i, err;
471
472 if (nvq->batched_xdp == 0)
473 goto signal_used;
474
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");
479
480
481
482
483
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;
487 nvq->done_idx = 0;
488 return;
489 }
490
491signal_used:
492 vhost_net_signal_used(nvq);
493 nvq->batched_xdp = 0;
494}
495
496static int sock_has_rx_data(struct socket *sock)
497{
498 if (unlikely(!sock))
499 return 0;
500
501 if (sock->ops->peek_len)
502 return sock->ops->peek_len(sock);
503
504 return skb_queue_empty(&sock->sk->sk_receive_queue);
505}
506
507static void vhost_net_busy_poll_try_queue(struct vhost_net *net,
508 struct vhost_virtqueue *vq)
509{
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);
515 }
516}
517
518static void vhost_net_busy_poll(struct vhost_net *net,
519 struct vhost_virtqueue *rvq,
520 struct vhost_virtqueue *tvq,
521 bool *busyloop_intr,
522 bool poll_rx)
523{
524 unsigned long busyloop_timeout;
525 unsigned long endtime;
526 struct socket *sock;
527 struct vhost_virtqueue *vq = poll_rx ? tvq : rvq;
528
529
530
531
532
533 if (!mutex_trylock(&vq->mutex))
534 return;
535
536 vhost_disable_notify(&net->dev, vq);
537 sock = vhost_vq_get_backend(rvq);
538
539 busyloop_timeout = poll_rx ? rvq->busyloop_timeout:
540 tvq->busyloop_timeout;
541
542 preempt_disable();
543 endtime = busy_clock() + busyloop_timeout;
544
545 while (vhost_can_busy_poll(endtime)) {
546 if (vhost_has_work(&net->dev)) {
547 *busyloop_intr = true;
548 break;
549 }
550
551 if ((sock_has_rx_data(sock) &&
552 !vhost_vq_avail_empty(&net->dev, rvq)) ||
553 !vhost_vq_avail_empty(&net->dev, tvq))
554 break;
555
556 cpu_relax();
557 }
558
559 preempt_enable();
560
561 if (poll_rx || sock_has_rx_data(sock))
562 vhost_net_busy_poll_try_queue(net, vq);
563 else if (!poll_rx)
564 vhost_enable_notify(&net->dev, rvq);
565
566 mutex_unlock(&vq->mutex);
567}
568
569static 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)
573{
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;
577
578 int r = vhost_get_vq_desc(tvq, tvq->iov, ARRAY_SIZE(tvq->iov),
579 out_num, in_num, NULL, NULL);
580
581 if (r == tvq->num && tvq->busyloop_timeout) {
582
583 if (!vhost_sock_zcopy(vhost_vq_get_backend(tvq)))
584 vhost_tx_batch(net, tnvq,
585 vhost_vq_get_backend(tvq),
586 msghdr);
587
588 vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, false);
589
590 r = vhost_get_vq_desc(tvq, tvq->iov, ARRAY_SIZE(tvq->iov),
591 out_num, in_num, NULL, NULL);
592 }
593
594 return r;
595}
596
597static bool vhost_exceeds_maxpend(struct vhost_net *net)
598{
599 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
600 struct vhost_virtqueue *vq = &nvq->vq;
601
602 return (nvq->upend_idx + UIO_MAXIOV - nvq->done_idx) % UIO_MAXIOV >
603 min_t(unsigned int, VHOST_MAX_PEND, vq->num >> 2);
604}
605
606static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter,
607 size_t hdr_size, int out)
608{
609
610 size_t len = iov_length(vq->iov, out);
611
612 iov_iter_init(iter, WRITE, vq->iov, out, len);
613 iov_iter_advance(iter, hdr_size);
614
615 return iov_iter_count(iter);
616}
617
618static int get_tx_bufs(struct vhost_net *net,
619 struct vhost_net_virtqueue *nvq,
620 struct msghdr *msg,
621 unsigned int *out, unsigned int *in,
622 size_t *len, bool *busyloop_intr)
623{
624 struct vhost_virtqueue *vq = &nvq->vq;
625 int ret;
626
627 ret = vhost_net_tx_get_vq_desc(net, nvq, out, in, msg, busyloop_intr);
628
629 if (ret < 0 || ret == vq->num)
630 return ret;
631
632 if (*in) {
633 vq_err(vq, "Unexpected descriptor format for TX: out %d, int %d\n",
634 *out, *in);
635 return -EFAULT;
636 }
637
638
639 *len = init_iov_iter(vq, &msg->msg_iter, nvq->vhost_hlen, *out);
640 if (*len == 0) {
641 vq_err(vq, "Unexpected header len for TX: %zd expected %zd\n",
642 *len, nvq->vhost_hlen);
643 return -EFAULT;
644 }
645
646 return ret;
647}
648
649static bool tx_can_batch(struct vhost_virtqueue *vq, size_t total_len)
650{
651 return total_len < VHOST_NET_WEIGHT &&
652 !vhost_vq_avail_empty(vq->dev, vq);
653}
654
655static bool vhost_net_page_frag_refill(struct vhost_net *net, unsigned int sz,
656 struct page_frag *pfrag, gfp_t gfp)
657{
658 if (pfrag->page) {
659 if (pfrag->offset + sz <= pfrag->size)
660 return true;
661 __page_frag_cache_drain(pfrag->page, net->refcnt_bias);
662 }
663
664 pfrag->offset = 0;
665 net->refcnt_bias = 0;
666 if (SKB_FRAG_PAGE_ORDER) {
667
668 pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
669 __GFP_COMP | __GFP_NOWARN |
670 __GFP_NORETRY,
671 SKB_FRAG_PAGE_ORDER);
672 if (likely(pfrag->page)) {
673 pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
674 goto done;
675 }
676 }
677 pfrag->page = alloc_page(gfp);
678 if (likely(pfrag->page)) {
679 pfrag->size = PAGE_SIZE;
680 goto done;
681 }
682 return false;
683
684done:
685 net->refcnt_bias = USHRT_MAX;
686 page_ref_add(pfrag->page, USHRT_MAX - 1);
687 return true;
688}
689
690#define VHOST_NET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
691
692static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq,
693 struct iov_iter *from)
694{
695 struct vhost_virtqueue *vq = &nvq->vq;
696 struct vhost_net *net = container_of(vq->dev, struct vhost_net,
697 dev);
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;
708 void *buf;
709 int copied;
710
711 if (unlikely(len < nvq->sock_hlen))
712 return -EFAULT;
713
714 if (SKB_DATA_ALIGN(len + pad) +
715 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
716 return -ENOSPC;
717
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)))
722 return -ENOMEM;
723
724 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
725 copied = copy_page_from_iter(alloc_frag->page,
726 alloc_frag->offset +
727 offsetof(struct tun_xdp_hdr, gso),
728 sock_hlen, from);
729 if (copied != sock_hlen)
730 return -EFAULT;
731
732 hdr = buf;
733 gso = &hdr->gso;
734
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);
742
743 if (vhost16_to_cpu(vq, gso->hdr_len) > len)
744 return -EINVAL;
745 }
746
747 len -= sock_hlen;
748 copied = copy_page_from_iter(alloc_frag->page,
749 alloc_frag->offset + pad,
750 len, from);
751 if (copied != len)
752 return -EFAULT;
753
754 xdp_init_buff(xdp, buflen, NULL);
755 xdp_prepare_buff(xdp, buf, pad, len, true);
756 hdr->buflen = buflen;
757
758 --net->refcnt_bias;
759 alloc_frag->offset += buflen;
760
761 ++nvq->batched_xdp;
762
763 return 0;
764}
765
766static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
767{
768 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
769 struct vhost_virtqueue *vq = &nvq->vq;
770 unsigned out, in;
771 int head;
772 struct msghdr msg = {
773 .msg_name = NULL,
774 .msg_namelen = 0,
775 .msg_control = NULL,
776 .msg_controllen = 0,
777 .msg_flags = MSG_DONTWAIT,
778 };
779 size_t len, total_len = 0;
780 int err;
781 int sent_pkts = 0;
782 bool sock_can_batch = (sock->sk->sk_sndbuf == INT_MAX);
783
784 do {
785 bool busyloop_intr = false;
786
787 if (nvq->done_idx == VHOST_NET_BATCH)
788 vhost_tx_batch(net, nvq, sock, &msg);
789
790 head = get_tx_bufs(net, nvq, &msg, &out, &in, &len,
791 &busyloop_intr);
792
793 if (unlikely(head < 0))
794 break;
795
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,
800 vq))) {
801 vhost_disable_notify(&net->dev, vq);
802 continue;
803 }
804 break;
805 }
806
807 total_len += len;
808
809
810
811
812 if (sock_can_batch) {
813 err = vhost_net_build_xdp(nvq, &msg.msg_iter);
814 if (!err) {
815 goto done;
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);
820 break;
821 }
822
823
824
825
826
827 vhost_tx_batch(net, nvq, sock, &msg);
828 msg.msg_control = NULL;
829 } else {
830 if (tx_can_batch(vq, total_len))
831 msg.msg_flags |= MSG_MORE;
832 else
833 msg.msg_flags &= ~MSG_MORE;
834 }
835
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);
841 break;
842 }
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",
846 err, len);
847done:
848 vq->heads[nvq->done_idx].id = cpu_to_vhost32(vq, head);
849 vq->heads[nvq->done_idx].len = 0;
850 ++nvq->done_idx;
851 } while (likely(!vhost_exceeds_weight(vq, ++sent_pkts, total_len)));
852
853 vhost_tx_batch(net, nvq, sock, &msg);
854}
855
856static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
857{
858 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
859 struct vhost_virtqueue *vq = &nvq->vq;
860 unsigned out, in;
861 int head;
862 struct msghdr msg = {
863 .msg_name = NULL,
864 .msg_namelen = 0,
865 .msg_control = NULL,
866 .msg_controllen = 0,
867 .msg_flags = MSG_DONTWAIT,
868 };
869 struct tun_msg_ctl ctl;
870 size_t len, total_len = 0;
871 int err;
872 struct vhost_net_ubuf_ref *ubufs;
873 struct ubuf_info *ubuf;
874 bool zcopy_used;
875 int sent_pkts = 0;
876
877 do {
878 bool busyloop_intr;
879
880
881 vhost_zerocopy_signal_used(net, vq);
882
883 busyloop_intr = false;
884 head = get_tx_bufs(net, nvq, &msg, &out, &in, &len,
885 &busyloop_intr);
886
887 if (unlikely(head < 0))
888 break;
889
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);
895 continue;
896 }
897 break;
898 }
899
900 zcopy_used = len >= VHOST_GOODCOPY_LEN
901 && !vhost_exceeds_maxpend(net)
902 && vhost_net_tx_select_zcopy(net);
903
904
905 if (zcopy_used) {
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;
916 ctl.ptr = ubuf;
917 msg.msg_controllen = sizeof(ctl);
918 ubufs = nvq->ubufs;
919 atomic_inc(&ubufs->refcount);
920 nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
921 } else {
922 msg.msg_control = NULL;
923 ubufs = NULL;
924 }
925 total_len += len;
926 if (tx_can_batch(vq, total_len) &&
927 likely(!vhost_exceeds_maxpend(net))) {
928 msg.msg_flags |= MSG_MORE;
929 } else {
930 msg.msg_flags &= ~MSG_MORE;
931 }
932
933 err = sock->ops->sendmsg(sock, &msg, len);
934 if (unlikely(err < 0)) {
935 if (zcopy_used) {
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)
939 % UIO_MAXIOV;
940 }
941 if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) {
942 vhost_discard_vq_desc(vq, 1);
943 vhost_net_enable_vq(net, vq);
944 break;
945 }
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);
950 if (!zcopy_used)
951 vhost_add_used_and_signal(&net->dev, vq, head, 0);
952 else
953 vhost_zerocopy_signal_used(net, vq);
954 vhost_net_tx_packet(net);
955 } while (likely(!vhost_exceeds_weight(vq, ++sent_pkts, total_len)));
956}
957
958
959
960static void handle_tx(struct vhost_net *net)
961{
962 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
963 struct vhost_virtqueue *vq = &nvq->vq;
964 struct socket *sock;
965
966 mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_TX);
967 sock = vhost_vq_get_backend(vq);
968 if (!sock)
969 goto out;
970
971 if (!vq_meta_prefetch(vq))
972 goto out;
973
974 vhost_disable_notify(&net->dev, vq);
975 vhost_net_disable_vq(net, vq);
976
977 if (vhost_sock_zcopy(sock))
978 handle_tx_zerocopy(net, sock);
979 else
980 handle_tx_copy(net, sock);
981
982out:
983 mutex_unlock(&vq->mutex);
984}
985
986static int peek_head_len(struct vhost_net_virtqueue *rvq, struct sock *sk)
987{
988 struct sk_buff *head;
989 int len = 0;
990 unsigned long flags;
991
992 if (rvq->rx_ring)
993 return vhost_net_buf_peek(rvq);
994
995 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
996 head = skb_peek(&sk->sk_receive_queue);
997 if (likely(head)) {
998 len = head->len;
999 if (skb_vlan_tag_present(head))
1000 len += VLAN_HLEN;
1001 }
1002
1003 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
1004 return len;
1005}
1006
1007static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk,
1008 bool *busyloop_intr)
1009{
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);
1015
1016 if (!len && rvq->busyloop_timeout) {
1017
1018 vhost_net_signal_used(rnvq);
1019
1020 vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, true);
1021
1022 len = peek_head_len(rnvq, sk);
1023 }
1024
1025 return len;
1026}
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038static int get_rx_bufs(struct vhost_virtqueue *vq,
1039 struct vring_used_elem *heads,
1040 int datalen,
1041 unsigned *iovcount,
1042 struct vhost_log *log,
1043 unsigned *log_num,
1044 unsigned int quota)
1045{
1046 unsigned int out, in;
1047 int seg = 0;
1048 int headcount = 0;
1049 unsigned d;
1050 int r, nlogs = 0;
1051
1052
1053
1054 u32 len;
1055
1056 while (datalen > 0 && headcount < quota) {
1057 if (unlikely(seg >= UIO_MAXIOV)) {
1058 r = -ENOBUFS;
1059 goto err;
1060 }
1061 r = vhost_get_vq_desc(vq, vq->iov + seg,
1062 ARRAY_SIZE(vq->iov) - seg, &out,
1063 &in, log, log_num);
1064 if (unlikely(r < 0))
1065 goto err;
1066
1067 d = r;
1068 if (d == vq->num) {
1069 r = 0;
1070 goto err;
1071 }
1072 if (unlikely(out || in <= 0)) {
1073 vq_err(vq, "unexpected descriptor format for RX: "
1074 "out %d, in %d\n", out, in);
1075 r = -EINVAL;
1076 goto err;
1077 }
1078 if (unlikely(log)) {
1079 nlogs += *log_num;
1080 log += *log_num;
1081 }
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);
1085 datalen -= len;
1086 ++headcount;
1087 seg += in;
1088 }
1089 heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen);
1090 *iovcount = seg;
1091 if (unlikely(log))
1092 *log_num = nlogs;
1093
1094
1095 if (unlikely(datalen > 0)) {
1096 r = UIO_MAXIOV + 1;
1097 goto err;
1098 }
1099 return headcount;
1100err:
1101 vhost_discard_vq_desc(vq, headcount);
1102 return r;
1103}
1104
1105
1106
1107static void handle_rx(struct vhost_net *net)
1108{
1109 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX];
1110 struct vhost_virtqueue *vq = &nvq->vq;
1111 unsigned in, log;
1112 struct vhost_log *vq_log;
1113 struct msghdr msg = {
1114 .msg_name = NULL,
1115 .msg_namelen = 0,
1116 .msg_control = NULL,
1117 .msg_controllen = 0,
1118 .msg_flags = MSG_DONTWAIT,
1119 };
1120 struct virtio_net_hdr hdr = {
1121 .flags = 0,
1122 .gso_type = VIRTIO_NET_HDR_GSO_NONE
1123 };
1124 size_t total_len = 0;
1125 int err, mergeable;
1126 s16 headcount;
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;
1133 int recv_pkts = 0;
1134
1135 mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
1136 sock = vhost_vq_get_backend(vq);
1137 if (!sock)
1138 goto out;
1139
1140 if (!vq_meta_prefetch(vq))
1141 goto out;
1142
1143 vhost_disable_notify(&net->dev, vq);
1144 vhost_net_disable_vq(net, vq);
1145
1146 vhost_hlen = nvq->vhost_hlen;
1147 sock_hlen = nvq->sock_hlen;
1148
1149 vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ?
1150 vq->log : NULL;
1151 mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
1152
1153 do {
1154 sock_len = vhost_net_rx_peek_head_len(net, sock->sk,
1155 &busyloop_intr);
1156 if (!sock_len)
1157 break;
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
1164 if (unlikely(headcount < 0))
1165 goto out;
1166
1167 if (!headcount) {
1168 if (unlikely(busyloop_intr)) {
1169 vhost_poll_queue(&vq->poll);
1170 } else if (unlikely(vhost_enable_notify(&net->dev, vq))) {
1171
1172
1173 vhost_disable_notify(&net->dev, vq);
1174 continue;
1175 }
1176
1177
1178 goto out;
1179 }
1180 busyloop_intr = false;
1181 if (nvq->rx_ring)
1182 msg.msg_control = vhost_net_buf_consume(&nvq->rxq);
1183
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);
1189 continue;
1190 }
1191
1192 iov_iter_init(&msg.msg_iter, READ, vq->iov, in, vhost_len);
1193 fixup = msg.msg_iter;
1194 if (unlikely((vhost_hlen))) {
1195
1196
1197
1198 iov_iter_advance(&msg.msg_iter, vhost_hlen);
1199 }
1200 err = sock->ops->recvmsg(sock, &msg,
1201 sock_len, MSG_DONTWAIT | MSG_TRUNC);
1202
1203
1204
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);
1209 continue;
1210 }
1211
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);
1217 goto out;
1218 }
1219 } else {
1220
1221
1222
1223 iov_iter_advance(&fixup, sizeof(hdr));
1224 }
1225
1226
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);
1233 goto out;
1234 }
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 vq->iov, in);
1241 total_len += vhost_len;
1242 } while (likely(!vhost_exceeds_weight(vq, ++recv_pkts, total_len)));
1243
1244 if (unlikely(busyloop_intr))
1245 vhost_poll_queue(&vq->poll);
1246 else if (!sock_len)
1247 vhost_net_enable_vq(net, vq);
1248out:
1249 vhost_net_signal_used(nvq);
1250 mutex_unlock(&vq->mutex);
1251}
1252
1253static void handle_tx_kick(struct vhost_work *work)
1254{
1255 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1256 poll.work);
1257 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
1258
1259 handle_tx(net);
1260}
1261
1262static void handle_rx_kick(struct vhost_work *work)
1263{
1264 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1265 poll.work);
1266 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
1267
1268 handle_rx(net);
1269}
1270
1271static void handle_tx_net(struct vhost_work *work)
1272{
1273 struct vhost_net *net = container_of(work, struct vhost_net,
1274 poll[VHOST_NET_VQ_TX].work);
1275 handle_tx(net);
1276}
1277
1278static void handle_rx_net(struct vhost_work *work)
1279{
1280 struct vhost_net *net = container_of(work, struct vhost_net,
1281 poll[VHOST_NET_VQ_RX].work);
1282 handle_rx(net);
1283}
1284
1285static int vhost_net_open(struct inode *inode, struct file *f)
1286{
1287 struct vhost_net *n;
1288 struct vhost_dev *dev;
1289 struct vhost_virtqueue **vqs;
1290 void **queue;
1291 struct xdp_buff *xdp;
1292 int i;
1293
1294 n = kvmalloc(sizeof *n, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1295 if (!n)
1296 return -ENOMEM;
1297 vqs = kmalloc_array(VHOST_NET_VQ_MAX, sizeof(*vqs), GFP_KERNEL);
1298 if (!vqs) {
1299 kvfree(n);
1300 return -ENOMEM;
1301 }
1302
1303 queue = kmalloc_array(VHOST_NET_BATCH, sizeof(void *),
1304 GFP_KERNEL);
1305 if (!queue) {
1306 kfree(vqs);
1307 kvfree(n);
1308 return -ENOMEM;
1309 }
1310 n->vqs[VHOST_NET_VQ_RX].rxq.queue = queue;
1311
1312 xdp = kmalloc_array(VHOST_NET_BATCH, sizeof(*xdp), GFP_KERNEL);
1313 if (!xdp) {
1314 kfree(vqs);
1315 kvfree(n);
1316 kfree(queue);
1317 return -ENOMEM;
1318 }
1319 n->vqs[VHOST_NET_VQ_TX].xdp = xdp;
1320
1321 dev = &n->dev;
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);
1336 }
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,
1340 NULL);
1341
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);
1344
1345 f->private_data = n;
1346 n->page_frag.page = NULL;
1347 n->refcnt_bias = 0;
1348
1349 return 0;
1350}
1351
1352static struct socket *vhost_net_stop_vq(struct vhost_net *n,
1353 struct vhost_virtqueue *vq)
1354{
1355 struct socket *sock;
1356 struct vhost_net_virtqueue *nvq =
1357 container_of(vq, struct vhost_net_virtqueue, vq);
1358
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);
1366 return sock;
1367}
1368
1369static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
1370 struct socket **rx_sock)
1371{
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);
1374}
1375
1376static void vhost_net_flush_vq(struct vhost_net *n, int index)
1377{
1378 vhost_poll_flush(n->poll + index);
1379 vhost_poll_flush(&n->vqs[index].vq.poll);
1380}
1381
1382static void vhost_net_flush(struct vhost_net *n)
1383{
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);
1388 n->tx_flush = true;
1389 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
1390
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);
1396 }
1397}
1398
1399static int vhost_net_release(struct inode *inode, struct file *f)
1400{
1401 struct vhost_net *n = f->private_data;
1402 struct socket *tx_sock;
1403 struct socket *rx_sock;
1404
1405 vhost_net_stop(n, &tx_sock, &rx_sock);
1406 vhost_net_flush(n);
1407 vhost_dev_stop(&n->dev);
1408 vhost_dev_cleanup(&n->dev);
1409 vhost_net_vq_reset(n);
1410 if (tx_sock)
1411 sockfd_put(tx_sock);
1412 if (rx_sock)
1413 sockfd_put(rx_sock);
1414
1415 synchronize_rcu();
1416
1417
1418 vhost_net_flush(n);
1419 kfree(n->vqs[VHOST_NET_VQ_RX].rxq.queue);
1420 kfree(n->vqs[VHOST_NET_VQ_TX].xdp);
1421 kfree(n->dev.vqs);
1422 if (n->page_frag.page)
1423 __page_frag_cache_drain(n->page_frag.page, n->refcnt_bias);
1424 kvfree(n);
1425 return 0;
1426}
1427
1428static struct socket *get_raw_socket(int fd)
1429{
1430 int r;
1431 struct socket *sock = sockfd_lookup(fd, &r);
1432
1433 if (!sock)
1434 return ERR_PTR(-ENOTSOCK);
1435
1436
1437 if (sock->sk->sk_type != SOCK_RAW) {
1438 r = -ESOCKTNOSUPPORT;
1439 goto err;
1440 }
1441
1442 if (sock->sk->sk_family != AF_PACKET) {
1443 r = -EPFNOSUPPORT;
1444 goto err;
1445 }
1446 return sock;
1447err:
1448 sockfd_put(sock);
1449 return ERR_PTR(r);
1450}
1451
1452static struct ptr_ring *get_tap_ptr_ring(int fd)
1453{
1454 struct ptr_ring *ring;
1455 struct file *file = fget(fd);
1456
1457 if (!file)
1458 return NULL;
1459 ring = tun_get_tx_ring(file);
1460 if (!IS_ERR(ring))
1461 goto out;
1462 ring = tap_get_ptr_ring(file);
1463 if (!IS_ERR(ring))
1464 goto out;
1465 ring = NULL;
1466out:
1467 fput(file);
1468 return ring;
1469}
1470
1471static struct socket *get_tap_socket(int fd)
1472{
1473 struct file *file = fget(fd);
1474 struct socket *sock;
1475
1476 if (!file)
1477 return ERR_PTR(-EBADF);
1478 sock = tun_get_socket(file);
1479 if (!IS_ERR(sock))
1480 return sock;
1481 sock = tap_get_socket(file);
1482 if (IS_ERR(sock))
1483 fput(file);
1484 return sock;
1485}
1486
1487static struct socket *get_socket(int fd)
1488{
1489 struct socket *sock;
1490
1491
1492 if (fd == -1)
1493 return NULL;
1494 sock = get_raw_socket(fd);
1495 if (!IS_ERR(sock))
1496 return sock;
1497 sock = get_tap_socket(fd);
1498 if (!IS_ERR(sock))
1499 return sock;
1500 return ERR_PTR(-ENOTSOCK);
1501}
1502
1503static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
1504{
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;
1509 int r;
1510
1511 mutex_lock(&n->dev.mutex);
1512 r = vhost_dev_check_owner(&n->dev);
1513 if (r)
1514 goto err;
1515
1516 if (index >= VHOST_NET_VQ_MAX) {
1517 r = -ENOBUFS;
1518 goto err;
1519 }
1520 vq = &n->vqs[index].vq;
1521 nvq = &n->vqs[index];
1522 mutex_lock(&vq->mutex);
1523
1524
1525 if (!vhost_vq_access_ok(vq)) {
1526 r = -EFAULT;
1527 goto err_vq;
1528 }
1529 sock = get_socket(fd);
1530 if (IS_ERR(sock)) {
1531 r = PTR_ERR(sock);
1532 goto err_vq;
1533 }
1534
1535
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)) {
1541 r = PTR_ERR(ubufs);
1542 goto err_ubufs;
1543 }
1544
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);
1549 if (r)
1550 goto err_used;
1551 r = vhost_net_enable_vq(n, vq);
1552 if (r)
1553 goto err_used;
1554 if (index == VHOST_NET_VQ_RX)
1555 nvq->rx_ring = get_tap_ptr_ring(fd);
1556
1557 oldubufs = nvq->ubufs;
1558 nvq->ubufs = ubufs;
1559
1560 n->tx_packets = 0;
1561 n->tx_zcopy_err = 0;
1562 n->tx_flush = false;
1563 }
1564
1565 mutex_unlock(&vq->mutex);
1566
1567 if (oldubufs) {
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);
1572 }
1573
1574 if (oldsock) {
1575 vhost_net_flush_vq(n, index);
1576 sockfd_put(oldsock);
1577 }
1578
1579 mutex_unlock(&n->dev.mutex);
1580 return 0;
1581
1582err_used:
1583 vhost_vq_set_backend(vq, oldsock);
1584 vhost_net_enable_vq(n, vq);
1585 if (ubufs)
1586 vhost_net_ubuf_put_wait_and_free(ubufs);
1587err_ubufs:
1588 if (sock)
1589 sockfd_put(sock);
1590err_vq:
1591 mutex_unlock(&vq->mutex);
1592err:
1593 mutex_unlock(&n->dev.mutex);
1594 return r;
1595}
1596
1597static long vhost_net_reset_owner(struct vhost_net *n)
1598{
1599 struct socket *tx_sock = NULL;
1600 struct socket *rx_sock = NULL;
1601 long err;
1602 struct vhost_iotlb *umem;
1603
1604 mutex_lock(&n->dev.mutex);
1605 err = vhost_dev_check_owner(&n->dev);
1606 if (err)
1607 goto done;
1608 umem = vhost_dev_reset_owner_prepare();
1609 if (!umem) {
1610 err = -ENOMEM;
1611 goto done;
1612 }
1613 vhost_net_stop(n, &tx_sock, &rx_sock);
1614 vhost_net_flush(n);
1615 vhost_dev_stop(&n->dev);
1616 vhost_dev_reset_owner(&n->dev, umem);
1617 vhost_net_vq_reset(n);
1618done:
1619 mutex_unlock(&n->dev.mutex);
1620 if (tx_sock)
1621 sockfd_put(tx_sock);
1622 if (rx_sock)
1623 sockfd_put(rx_sock);
1624 return err;
1625}
1626
1627static int vhost_net_set_features(struct vhost_net *n, u64 features)
1628{
1629 size_t vhost_hlen, sock_hlen, hdr_len;
1630 int i;
1631
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
1638 vhost_hlen = hdr_len;
1639 sock_hlen = 0;
1640 } else {
1641
1642 vhost_hlen = 0;
1643 sock_hlen = hdr_len;
1644 }
1645 mutex_lock(&n->dev.mutex);
1646 if ((features & (1 << VHOST_F_LOG_ALL)) &&
1647 !vhost_log_access_ok(&n->dev))
1648 goto out_unlock;
1649
1650 if ((features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) {
1651 if (vhost_init_device_iotlb(&n->dev, true))
1652 goto out_unlock;
1653 }
1654
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);
1661 }
1662 mutex_unlock(&n->dev.mutex);
1663 return 0;
1664
1665out_unlock:
1666 mutex_unlock(&n->dev.mutex);
1667 return -EFAULT;
1668}
1669
1670static long vhost_net_set_owner(struct vhost_net *n)
1671{
1672 int r;
1673
1674 mutex_lock(&n->dev.mutex);
1675 if (vhost_dev_has_owner(&n->dev)) {
1676 r = -EBUSY;
1677 goto out;
1678 }
1679 r = vhost_net_set_ubuf_info(n);
1680 if (r)
1681 goto out;
1682 r = vhost_dev_set_owner(&n->dev);
1683 if (r)
1684 vhost_net_clear_ubuf_info(n);
1685 vhost_net_flush(n);
1686out:
1687 mutex_unlock(&n->dev.mutex);
1688 return r;
1689}
1690
1691static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
1692 unsigned long arg)
1693{
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;
1698 u64 features;
1699 int r;
1700
1701 switch (ioctl) {
1702 case VHOST_NET_SET_BACKEND:
1703 if (copy_from_user(&backend, argp, sizeof backend))
1704 return -EFAULT;
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))
1709 return -EFAULT;
1710 return 0;
1711 case VHOST_SET_FEATURES:
1712 if (copy_from_user(&features, featurep, sizeof features))
1713 return -EFAULT;
1714 if (features & ~VHOST_NET_FEATURES)
1715 return -EOPNOTSUPP;
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)))
1720 return -EFAULT;
1721 return 0;
1722 case VHOST_SET_BACKEND_FEATURES:
1723 if (copy_from_user(&features, featurep, sizeof(features)))
1724 return -EFAULT;
1725 if (features & ~VHOST_NET_BACKEND_FEATURES)
1726 return -EOPNOTSUPP;
1727 vhost_set_backend_features(&n->dev, features);
1728 return 0;
1729 case VHOST_RESET_OWNER:
1730 return vhost_net_reset_owner(n);
1731 case VHOST_SET_OWNER:
1732 return vhost_net_set_owner(n);
1733 default:
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);
1738 else
1739 vhost_net_flush(n);
1740 mutex_unlock(&n->dev.mutex);
1741 return r;
1742 }
1743}
1744
1745static ssize_t vhost_net_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1746{
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;
1751
1752 return vhost_chr_read_iter(dev, to, noblock);
1753}
1754
1755static ssize_t vhost_net_chr_write_iter(struct kiocb *iocb,
1756 struct iov_iter *from)
1757{
1758 struct file *file = iocb->ki_filp;
1759 struct vhost_net *n = file->private_data;
1760 struct vhost_dev *dev = &n->dev;
1761
1762 return vhost_chr_write_iter(dev, from);
1763}
1764
1765static __poll_t vhost_net_chr_poll(struct file *file, poll_table *wait)
1766{
1767 struct vhost_net *n = file->private_data;
1768 struct vhost_dev *dev = &n->dev;
1769
1770 return vhost_chr_poll(file, dev, wait);
1771}
1772
1773static 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,
1783};
1784
1785static struct miscdevice vhost_net_misc = {
1786 .minor = VHOST_NET_MINOR,
1787 .name = "vhost-net",
1788 .fops = &vhost_net_fops,
1789};
1790
1791static int vhost_net_init(void)
1792{
1793 if (experimental_zcopytx)
1794 vhost_net_enable_zcopy(VHOST_NET_VQ_TX);
1795 return misc_register(&vhost_net_misc);
1796}
1797module_init(vhost_net_init);
1798
1799static void vhost_net_exit(void)
1800{
1801 misc_deregister(&vhost_net_misc);
1802}
1803module_exit(vhost_net_exit);
1804
1805MODULE_VERSION("0.0.1");
1806MODULE_LICENSE("GPL v2");
1807MODULE_AUTHOR("Michael S. Tsirkin");
1808MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1809MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
1810MODULE_ALIAS("devname:vhost-net");
1811