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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>
23
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>
33
34#include <net/sock.h>
35#include <net/xdp.h>
36
37#include "vhost.h"
38
39static int experimental_zcopytx;
40module_param(experimental_zcopytx, int, 0444);
41MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
42 " 1 -Enable; 0 - Disable");
43
44
45
46#define VHOST_NET_WEIGHT 0x80000
47
48
49
50
51
52#define VHOST_NET_PKT_WEIGHT 256
53
54
55#define VHOST_MAX_PEND 128
56#define VHOST_GOODCOPY_LEN 256
57
58
59
60
61
62
63#define VHOST_DMA_FAILED_LEN ((__force __virtio32)3)
64
65#define VHOST_DMA_DONE_LEN ((__force __virtio32)2)
66
67#define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1)
68
69#define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0)
70
71#define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN)
72
73enum {
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)
78};
79
80enum {
81 VHOST_NET_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2)
82};
83
84enum {
85 VHOST_NET_VQ_RX = 0,
86 VHOST_NET_VQ_TX = 1,
87 VHOST_NET_VQ_MAX = 2,
88};
89
90struct vhost_net_ubuf_ref {
91
92
93
94
95
96 atomic_t refcount;
97 wait_queue_head_t wait;
98 struct vhost_virtqueue *vq;
99};
100
101#define VHOST_NET_BATCH 64
102struct vhost_net_buf {
103 void **queue;
104 int tail;
105 int head;
106};
107
108struct vhost_net_virtqueue {
109 struct vhost_virtqueue vq;
110 size_t vhost_hlen;
111 size_t sock_hlen;
112
113
114 int upend_idx;
115
116
117
118 int done_idx;
119
120 int batched_xdp;
121
122 struct ubuf_info *ubuf_info;
123
124
125 struct vhost_net_ubuf_ref *ubufs;
126 struct ptr_ring *rx_ring;
127 struct vhost_net_buf rxq;
128
129 struct xdp_buff *xdp;
130};
131
132struct vhost_net {
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
137
138 unsigned tx_packets;
139
140
141 unsigned tx_zcopy_err;
142
143 bool tx_flush;
144
145 struct page_frag page_frag;
146
147 int refcnt_bias;
148};
149
150static unsigned vhost_net_zcopy_mask __read_mostly;
151
152static void *vhost_net_buf_get_ptr(struct vhost_net_buf *rxq)
153{
154 if (rxq->tail != rxq->head)
155 return rxq->queue[rxq->head];
156 else
157 return NULL;
158}
159
160static int vhost_net_buf_get_size(struct vhost_net_buf *rxq)
161{
162 return rxq->tail - rxq->head;
163}
164
165static int vhost_net_buf_is_empty(struct vhost_net_buf *rxq)
166{
167 return rxq->tail == rxq->head;
168}
169
170static void *vhost_net_buf_consume(struct vhost_net_buf *rxq)
171{
172 void *ret = vhost_net_buf_get_ptr(rxq);
173 ++rxq->head;
174 return ret;
175}
176
177static int vhost_net_buf_produce(struct vhost_net_virtqueue *nvq)
178{
179 struct vhost_net_buf *rxq = &nvq->rxq;
180
181 rxq->head = 0;
182 rxq->tail = ptr_ring_consume_batched(nvq->rx_ring, rxq->queue,
183 VHOST_NET_BATCH);
184 return rxq->tail;
185}
186
187static void vhost_net_buf_unproduce(struct vhost_net_virtqueue *nvq)
188{
189 struct vhost_net_buf *rxq = &nvq->rxq;
190
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),
194 tun_ptr_free);
195 rxq->head = rxq->tail = 0;
196 }
197}
198
199static int vhost_net_buf_peek_len(void *ptr)
200{
201 if (tun_is_xdp_frame(ptr)) {
202 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
203
204 return xdpf->len;
205 }
206
207 return __skb_array_len_with_tag(ptr);
208}
209
210static int vhost_net_buf_peek(struct vhost_net_virtqueue *nvq)
211{
212 struct vhost_net_buf *rxq = &nvq->rxq;
213
214 if (!vhost_net_buf_is_empty(rxq))
215 goto out;
216
217 if (!vhost_net_buf_produce(nvq))
218 return 0;
219
220out:
221 return vhost_net_buf_peek_len(vhost_net_buf_get_ptr(rxq));
222}
223
224static void vhost_net_buf_init(struct vhost_net_buf *rxq)
225{
226 rxq->head = rxq->tail = 0;
227}
228
229static void vhost_net_enable_zcopy(int vq)
230{
231 vhost_net_zcopy_mask |= 0x1 << vq;
232}
233
234static struct vhost_net_ubuf_ref *
235vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy)
236{
237 struct vhost_net_ubuf_ref *ubufs;
238
239 if (!zcopy)
240 return NULL;
241 ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL);
242 if (!ubufs)
243 return ERR_PTR(-ENOMEM);
244 atomic_set(&ubufs->refcount, 1);
245 init_waitqueue_head(&ubufs->wait);
246 ubufs->vq = vq;
247 return ubufs;
248}
249
250static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
251{
252 int r = atomic_sub_return(1, &ubufs->refcount);
253 if (unlikely(!r))
254 wake_up(&ubufs->wait);
255 return r;
256}
257
258static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs)
259{
260 vhost_net_ubuf_put(ubufs);
261 wait_event(ubufs->wait, !atomic_read(&ubufs->refcount));
262}
263
264static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs)
265{
266 vhost_net_ubuf_put_and_wait(ubufs);
267 kfree(ubufs);
268}
269
270static void vhost_net_clear_ubuf_info(struct vhost_net *n)
271{
272 int i;
273
274 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
275 kfree(n->vqs[i].ubuf_info);
276 n->vqs[i].ubuf_info = NULL;
277 }
278}
279
280static int vhost_net_set_ubuf_info(struct vhost_net *n)
281{
282 bool zcopy;
283 int i;
284
285 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
286 zcopy = vhost_net_zcopy_mask & (0x1 << i);
287 if (!zcopy)
288 continue;
289 n->vqs[i].ubuf_info =
290 kmalloc_array(UIO_MAXIOV,
291 sizeof(*n->vqs[i].ubuf_info),
292 GFP_KERNEL);
293 if (!n->vqs[i].ubuf_info)
294 goto err;
295 }
296 return 0;
297
298err:
299 vhost_net_clear_ubuf_info(n);
300 return -ENOMEM;
301}
302
303static void vhost_net_vq_reset(struct vhost_net *n)
304{
305 int i;
306
307 vhost_net_clear_ubuf_info(n);
308
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);
316 }
317
318}
319
320static void vhost_net_tx_packet(struct vhost_net *net)
321{
322 ++net->tx_packets;
323 if (net->tx_packets < 1024)
324 return;
325 net->tx_packets = 0;
326 net->tx_zcopy_err = 0;
327}
328
329static void vhost_net_tx_err(struct vhost_net *net)
330{
331 ++net->tx_zcopy_err;
332}
333
334static bool vhost_net_tx_select_zcopy(struct vhost_net *net)
335{
336
337
338
339 return !net->tx_flush &&
340 net->tx_packets / 64 >= net->tx_zcopy_err;
341}
342
343static bool vhost_sock_zcopy(struct socket *sock)
344{
345 return unlikely(experimental_zcopytx) &&
346 sock_flag(sock->sk, SOCK_ZEROCOPY);
347}
348
349static bool vhost_sock_xdp(struct socket *sock)
350{
351 return sock_flag(sock->sk, SOCK_XDP);
352}
353
354
355
356
357
358
359static void vhost_zerocopy_signal_used(struct vhost_net *net,
360 struct vhost_virtqueue *vq)
361{
362 struct vhost_net_virtqueue *nvq =
363 container_of(vq, struct vhost_net_virtqueue, vq);
364 int i, add;
365 int j = 0;
366
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;
372 ++j;
373 } else
374 break;
375 }
376 while (j) {
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;
381 j -= add;
382 }
383}
384
385static void vhost_zerocopy_callback(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 (!vq->private_data)
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 = vq->private_data;
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 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 return;
480 }
481
482signal_used:
483 vhost_net_signal_used(nvq);
484 nvq->batched_xdp = 0;
485}
486
487static int sock_has_rx_data(struct socket *sock)
488{
489 if (unlikely(!sock))
490 return 0;
491
492 if (sock->ops->peek_len)
493 return sock->ops->peek_len(sock);
494
495 return skb_queue_empty(&sock->sk->sk_receive_queue);
496}
497
498static void vhost_net_busy_poll_try_queue(struct vhost_net *net,
499 struct vhost_virtqueue *vq)
500{
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);
506 }
507}
508
509static void vhost_net_busy_poll(struct vhost_net *net,
510 struct vhost_virtqueue *rvq,
511 struct vhost_virtqueue *tvq,
512 bool *busyloop_intr,
513 bool poll_rx)
514{
515 unsigned long busyloop_timeout;
516 unsigned long endtime;
517 struct socket *sock;
518 struct vhost_virtqueue *vq = poll_rx ? tvq : rvq;
519
520
521
522
523
524 if (!mutex_trylock(&vq->mutex))
525 return;
526
527 vhost_disable_notify(&net->dev, vq);
528 sock = rvq->private_data;
529
530 busyloop_timeout = poll_rx ? rvq->busyloop_timeout:
531 tvq->busyloop_timeout;
532
533 preempt_disable();
534 endtime = busy_clock() + busyloop_timeout;
535
536 while (vhost_can_busy_poll(endtime)) {
537 if (vhost_has_work(&net->dev)) {
538 *busyloop_intr = true;
539 break;
540 }
541
542 if ((sock_has_rx_data(sock) &&
543 !vhost_vq_avail_empty(&net->dev, rvq)) ||
544 !vhost_vq_avail_empty(&net->dev, tvq))
545 break;
546
547 cpu_relax();
548 }
549
550 preempt_enable();
551
552 if (poll_rx || sock_has_rx_data(sock))
553 vhost_net_busy_poll_try_queue(net, vq);
554 else if (!poll_rx)
555 vhost_enable_notify(&net->dev, rvq);
556
557 mutex_unlock(&vq->mutex);
558}
559
560static 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)
564{
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;
568
569 int r = vhost_get_vq_desc(tvq, tvq->iov, ARRAY_SIZE(tvq->iov),
570 out_num, in_num, NULL, NULL);
571
572 if (r == tvq->num && tvq->busyloop_timeout) {
573
574 if (!vhost_sock_zcopy(tvq->private_data))
575 vhost_tx_batch(net, tnvq, tvq->private_data, msghdr);
576
577 vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, false);
578
579 r = vhost_get_vq_desc(tvq, tvq->iov, ARRAY_SIZE(tvq->iov),
580 out_num, in_num, NULL, NULL);
581 }
582
583 return r;
584}
585
586static bool vhost_exceeds_maxpend(struct vhost_net *net)
587{
588 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
589 struct vhost_virtqueue *vq = &nvq->vq;
590
591 return (nvq->upend_idx + UIO_MAXIOV - nvq->done_idx) % UIO_MAXIOV >
592 min_t(unsigned int, VHOST_MAX_PEND, vq->num >> 2);
593}
594
595static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter,
596 size_t hdr_size, int out)
597{
598
599 size_t len = iov_length(vq->iov, out);
600
601 iov_iter_init(iter, WRITE, vq->iov, out, len);
602 iov_iter_advance(iter, hdr_size);
603
604 return iov_iter_count(iter);
605}
606
607static int get_tx_bufs(struct vhost_net *net,
608 struct vhost_net_virtqueue *nvq,
609 struct msghdr *msg,
610 unsigned int *out, unsigned int *in,
611 size_t *len, bool *busyloop_intr)
612{
613 struct vhost_virtqueue *vq = &nvq->vq;
614 int ret;
615
616 ret = vhost_net_tx_get_vq_desc(net, nvq, out, in, msg, busyloop_intr);
617
618 if (ret < 0 || ret == vq->num)
619 return ret;
620
621 if (*in) {
622 vq_err(vq, "Unexpected descriptor format for TX: out %d, int %d\n",
623 *out, *in);
624 return -EFAULT;
625 }
626
627
628 *len = init_iov_iter(vq, &msg->msg_iter, nvq->vhost_hlen, *out);
629 if (*len == 0) {
630 vq_err(vq, "Unexpected header len for TX: %zd expected %zd\n",
631 *len, nvq->vhost_hlen);
632 return -EFAULT;
633 }
634
635 return ret;
636}
637
638static bool tx_can_batch(struct vhost_virtqueue *vq, size_t total_len)
639{
640 return total_len < VHOST_NET_WEIGHT &&
641 !vhost_vq_avail_empty(vq->dev, vq);
642}
643
644#define SKB_FRAG_PAGE_ORDER get_order(32768)
645
646static bool vhost_net_page_frag_refill(struct vhost_net *net, unsigned int sz,
647 struct page_frag *pfrag, gfp_t gfp)
648{
649 if (pfrag->page) {
650 if (pfrag->offset + sz <= pfrag->size)
651 return true;
652 __page_frag_cache_drain(pfrag->page, net->refcnt_bias);
653 }
654
655 pfrag->offset = 0;
656 net->refcnt_bias = 0;
657 if (SKB_FRAG_PAGE_ORDER) {
658
659 pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
660 __GFP_COMP | __GFP_NOWARN |
661 __GFP_NORETRY,
662 SKB_FRAG_PAGE_ORDER);
663 if (likely(pfrag->page)) {
664 pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
665 goto done;
666 }
667 }
668 pfrag->page = alloc_page(gfp);
669 if (likely(pfrag->page)) {
670 pfrag->size = PAGE_SIZE;
671 goto done;
672 }
673 return false;
674
675done:
676 net->refcnt_bias = USHRT_MAX;
677 page_ref_add(pfrag->page, USHRT_MAX - 1);
678 return true;
679}
680
681#define VHOST_NET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
682
683static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq,
684 struct iov_iter *from)
685{
686 struct vhost_virtqueue *vq = &nvq->vq;
687 struct vhost_net *net = container_of(vq->dev, struct vhost_net,
688 dev);
689 struct socket *sock = vq->private_data;
690 struct page_frag *alloc_frag = &net->page_frag;
691 struct virtio_net_hdr *gso;
692 struct xdp_buff *xdp = &nvq->xdp[nvq->batched_xdp];
693 struct tun_xdp_hdr *hdr;
694 size_t len = iov_iter_count(from);
695 int headroom = vhost_sock_xdp(sock) ? XDP_PACKET_HEADROOM : 0;
696 int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
697 int pad = SKB_DATA_ALIGN(VHOST_NET_RX_PAD + headroom + nvq->sock_hlen);
698 int sock_hlen = nvq->sock_hlen;
699 void *buf;
700 int copied;
701
702 if (unlikely(len < nvq->sock_hlen))
703 return -EFAULT;
704
705 if (SKB_DATA_ALIGN(len + pad) +
706 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
707 return -ENOSPC;
708
709 buflen += SKB_DATA_ALIGN(len + pad);
710 alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
711 if (unlikely(!vhost_net_page_frag_refill(net, buflen,
712 alloc_frag, GFP_KERNEL)))
713 return -ENOMEM;
714
715 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
716 copied = copy_page_from_iter(alloc_frag->page,
717 alloc_frag->offset +
718 offsetof(struct tun_xdp_hdr, gso),
719 sock_hlen, from);
720 if (copied != sock_hlen)
721 return -EFAULT;
722
723 hdr = buf;
724 gso = &hdr->gso;
725
726 if ((gso->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
727 vhost16_to_cpu(vq, gso->csum_start) +
728 vhost16_to_cpu(vq, gso->csum_offset) + 2 >
729 vhost16_to_cpu(vq, gso->hdr_len)) {
730 gso->hdr_len = cpu_to_vhost16(vq,
731 vhost16_to_cpu(vq, gso->csum_start) +
732 vhost16_to_cpu(vq, gso->csum_offset) + 2);
733
734 if (vhost16_to_cpu(vq, gso->hdr_len) > len)
735 return -EINVAL;
736 }
737
738 len -= sock_hlen;
739 copied = copy_page_from_iter(alloc_frag->page,
740 alloc_frag->offset + pad,
741 len, from);
742 if (copied != len)
743 return -EFAULT;
744
745 xdp->data_hard_start = buf;
746 xdp->data = buf + pad;
747 xdp->data_end = xdp->data + len;
748 hdr->buflen = buflen;
749
750 --net->refcnt_bias;
751 alloc_frag->offset += buflen;
752
753 ++nvq->batched_xdp;
754
755 return 0;
756}
757
758static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
759{
760 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
761 struct vhost_virtqueue *vq = &nvq->vq;
762 unsigned out, in;
763 int head;
764 struct msghdr msg = {
765 .msg_name = NULL,
766 .msg_namelen = 0,
767 .msg_control = NULL,
768 .msg_controllen = 0,
769 .msg_flags = MSG_DONTWAIT,
770 };
771 size_t len, total_len = 0;
772 int err;
773 int sent_pkts = 0;
774 bool sock_can_batch = (sock->sk->sk_sndbuf == INT_MAX);
775
776 do {
777 bool busyloop_intr = false;
778
779 if (nvq->done_idx == VHOST_NET_BATCH)
780 vhost_tx_batch(net, nvq, sock, &msg);
781
782 head = get_tx_bufs(net, nvq, &msg, &out, &in, &len,
783 &busyloop_intr);
784
785 if (unlikely(head < 0))
786 break;
787
788 if (head == vq->num) {
789 if (unlikely(busyloop_intr)) {
790 vhost_poll_queue(&vq->poll);
791 } else if (unlikely(vhost_enable_notify(&net->dev,
792 vq))) {
793 vhost_disable_notify(&net->dev, vq);
794 continue;
795 }
796 break;
797 }
798
799 total_len += len;
800
801
802
803
804 if (sock_can_batch) {
805 err = vhost_net_build_xdp(nvq, &msg.msg_iter);
806 if (!err) {
807 goto done;
808 } else if (unlikely(err != -ENOSPC)) {
809 vhost_tx_batch(net, nvq, sock, &msg);
810 vhost_discard_vq_desc(vq, 1);
811 vhost_net_enable_vq(net, vq);
812 break;
813 }
814
815
816
817
818
819 vhost_tx_batch(net, nvq, sock, &msg);
820 msg.msg_control = NULL;
821 } else {
822 if (tx_can_batch(vq, total_len))
823 msg.msg_flags |= MSG_MORE;
824 else
825 msg.msg_flags &= ~MSG_MORE;
826 }
827
828
829 err = sock->ops->sendmsg(sock, &msg, len);
830 if (unlikely(err < 0)) {
831 vhost_discard_vq_desc(vq, 1);
832 vhost_net_enable_vq(net, vq);
833 break;
834 }
835 if (err != len)
836 pr_debug("Truncated TX packet: len %d != %zd\n",
837 err, len);
838done:
839 vq->heads[nvq->done_idx].id = cpu_to_vhost32(vq, head);
840 vq->heads[nvq->done_idx].len = 0;
841 ++nvq->done_idx;
842 } while (likely(!vhost_exceeds_weight(vq, ++sent_pkts, total_len)));
843
844 vhost_tx_batch(net, nvq, sock, &msg);
845}
846
847static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
848{
849 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
850 struct vhost_virtqueue *vq = &nvq->vq;
851 unsigned out, in;
852 int head;
853 struct msghdr msg = {
854 .msg_name = NULL,
855 .msg_namelen = 0,
856 .msg_control = NULL,
857 .msg_controllen = 0,
858 .msg_flags = MSG_DONTWAIT,
859 };
860 struct tun_msg_ctl ctl;
861 size_t len, total_len = 0;
862 int err;
863 struct vhost_net_ubuf_ref *uninitialized_var(ubufs);
864 bool zcopy_used;
865 int sent_pkts = 0;
866
867 do {
868 bool busyloop_intr;
869
870
871 vhost_zerocopy_signal_used(net, vq);
872
873 busyloop_intr = false;
874 head = get_tx_bufs(net, nvq, &msg, &out, &in, &len,
875 &busyloop_intr);
876
877 if (unlikely(head < 0))
878 break;
879
880 if (head == vq->num) {
881 if (unlikely(busyloop_intr)) {
882 vhost_poll_queue(&vq->poll);
883 } else if (unlikely(vhost_enable_notify(&net->dev, vq))) {
884 vhost_disable_notify(&net->dev, vq);
885 continue;
886 }
887 break;
888 }
889
890 zcopy_used = len >= VHOST_GOODCOPY_LEN
891 && !vhost_exceeds_maxpend(net)
892 && vhost_net_tx_select_zcopy(net);
893
894
895 if (zcopy_used) {
896 struct ubuf_info *ubuf;
897 ubuf = nvq->ubuf_info + nvq->upend_idx;
898
899 vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head);
900 vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
901 ubuf->callback = vhost_zerocopy_callback;
902 ubuf->ctx = nvq->ubufs;
903 ubuf->desc = nvq->upend_idx;
904 refcount_set(&ubuf->refcnt, 1);
905 msg.msg_control = &ctl;
906 ctl.type = TUN_MSG_UBUF;
907 ctl.ptr = ubuf;
908 msg.msg_controllen = sizeof(ctl);
909 ubufs = nvq->ubufs;
910 atomic_inc(&ubufs->refcount);
911 nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
912 } else {
913 msg.msg_control = NULL;
914 ubufs = NULL;
915 }
916 total_len += len;
917 if (tx_can_batch(vq, total_len) &&
918 likely(!vhost_exceeds_maxpend(net))) {
919 msg.msg_flags |= MSG_MORE;
920 } else {
921 msg.msg_flags &= ~MSG_MORE;
922 }
923
924
925 err = sock->ops->sendmsg(sock, &msg, len);
926 if (unlikely(err < 0)) {
927 if (zcopy_used) {
928 vhost_net_ubuf_put(ubufs);
929 nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
930 % UIO_MAXIOV;
931 }
932 vhost_discard_vq_desc(vq, 1);
933 vhost_net_enable_vq(net, vq);
934 break;
935 }
936 if (err != len)
937 pr_debug("Truncated TX packet: "
938 " len %d != %zd\n", err, len);
939 if (!zcopy_used)
940 vhost_add_used_and_signal(&net->dev, vq, head, 0);
941 else
942 vhost_zerocopy_signal_used(net, vq);
943 vhost_net_tx_packet(net);
944 } while (likely(!vhost_exceeds_weight(vq, ++sent_pkts, total_len)));
945}
946
947
948
949static void handle_tx(struct vhost_net *net)
950{
951 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
952 struct vhost_virtqueue *vq = &nvq->vq;
953 struct socket *sock;
954
955 mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_TX);
956 sock = vq->private_data;
957 if (!sock)
958 goto out;
959
960 if (!vq_iotlb_prefetch(vq))
961 goto out;
962
963 vhost_disable_notify(&net->dev, vq);
964 vhost_net_disable_vq(net, vq);
965
966 if (vhost_sock_zcopy(sock))
967 handle_tx_zerocopy(net, sock);
968 else
969 handle_tx_copy(net, sock);
970
971out:
972 mutex_unlock(&vq->mutex);
973}
974
975static int peek_head_len(struct vhost_net_virtqueue *rvq, struct sock *sk)
976{
977 struct sk_buff *head;
978 int len = 0;
979 unsigned long flags;
980
981 if (rvq->rx_ring)
982 return vhost_net_buf_peek(rvq);
983
984 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
985 head = skb_peek(&sk->sk_receive_queue);
986 if (likely(head)) {
987 len = head->len;
988 if (skb_vlan_tag_present(head))
989 len += VLAN_HLEN;
990 }
991
992 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
993 return len;
994}
995
996static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk,
997 bool *busyloop_intr)
998{
999 struct vhost_net_virtqueue *rnvq = &net->vqs[VHOST_NET_VQ_RX];
1000 struct vhost_net_virtqueue *tnvq = &net->vqs[VHOST_NET_VQ_TX];
1001 struct vhost_virtqueue *rvq = &rnvq->vq;
1002 struct vhost_virtqueue *tvq = &tnvq->vq;
1003 int len = peek_head_len(rnvq, sk);
1004
1005 if (!len && rvq->busyloop_timeout) {
1006
1007 vhost_net_signal_used(rnvq);
1008
1009 vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, true);
1010
1011 len = peek_head_len(rnvq, sk);
1012 }
1013
1014 return len;
1015}
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027static int get_rx_bufs(struct vhost_virtqueue *vq,
1028 struct vring_used_elem *heads,
1029 int datalen,
1030 unsigned *iovcount,
1031 struct vhost_log *log,
1032 unsigned *log_num,
1033 unsigned int quota)
1034{
1035 unsigned int out, in;
1036 int seg = 0;
1037 int headcount = 0;
1038 unsigned d;
1039 int r, nlogs = 0;
1040
1041
1042
1043 u32 uninitialized_var(len);
1044
1045 while (datalen > 0 && headcount < quota) {
1046 if (unlikely(seg >= UIO_MAXIOV)) {
1047 r = -ENOBUFS;
1048 goto err;
1049 }
1050 r = vhost_get_vq_desc(vq, vq->iov + seg,
1051 ARRAY_SIZE(vq->iov) - seg, &out,
1052 &in, log, log_num);
1053 if (unlikely(r < 0))
1054 goto err;
1055
1056 d = r;
1057 if (d == vq->num) {
1058 r = 0;
1059 goto err;
1060 }
1061 if (unlikely(out || in <= 0)) {
1062 vq_err(vq, "unexpected descriptor format for RX: "
1063 "out %d, in %d\n", out, in);
1064 r = -EINVAL;
1065 goto err;
1066 }
1067 if (unlikely(log)) {
1068 nlogs += *log_num;
1069 log += *log_num;
1070 }
1071 heads[headcount].id = cpu_to_vhost32(vq, d);
1072 len = iov_length(vq->iov + seg, in);
1073 heads[headcount].len = cpu_to_vhost32(vq, len);
1074 datalen -= len;
1075 ++headcount;
1076 seg += in;
1077 }
1078 heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen);
1079 *iovcount = seg;
1080 if (unlikely(log))
1081 *log_num = nlogs;
1082
1083
1084 if (unlikely(datalen > 0)) {
1085 r = UIO_MAXIOV + 1;
1086 goto err;
1087 }
1088 return headcount;
1089err:
1090 vhost_discard_vq_desc(vq, headcount);
1091 return r;
1092}
1093
1094
1095
1096static void handle_rx(struct vhost_net *net)
1097{
1098 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX];
1099 struct vhost_virtqueue *vq = &nvq->vq;
1100 unsigned uninitialized_var(in), log;
1101 struct vhost_log *vq_log;
1102 struct msghdr msg = {
1103 .msg_name = NULL,
1104 .msg_namelen = 0,
1105 .msg_control = NULL,
1106 .msg_controllen = 0,
1107 .msg_flags = MSG_DONTWAIT,
1108 };
1109 struct virtio_net_hdr hdr = {
1110 .flags = 0,
1111 .gso_type = VIRTIO_NET_HDR_GSO_NONE
1112 };
1113 size_t total_len = 0;
1114 int err, mergeable;
1115 s16 headcount;
1116 size_t vhost_hlen, sock_hlen;
1117 size_t vhost_len, sock_len;
1118 bool busyloop_intr = false;
1119 struct socket *sock;
1120 struct iov_iter fixup;
1121 __virtio16 num_buffers;
1122 int recv_pkts = 0;
1123
1124 mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
1125 sock = vq->private_data;
1126 if (!sock)
1127 goto out;
1128
1129 if (!vq_iotlb_prefetch(vq))
1130 goto out;
1131
1132 vhost_disable_notify(&net->dev, vq);
1133 vhost_net_disable_vq(net, vq);
1134
1135 vhost_hlen = nvq->vhost_hlen;
1136 sock_hlen = nvq->sock_hlen;
1137
1138 vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ?
1139 vq->log : NULL;
1140 mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
1141
1142 do {
1143 sock_len = vhost_net_rx_peek_head_len(net, sock->sk,
1144 &busyloop_intr);
1145 if (!sock_len)
1146 break;
1147 sock_len += sock_hlen;
1148 vhost_len = sock_len + vhost_hlen;
1149 headcount = get_rx_bufs(vq, vq->heads + nvq->done_idx,
1150 vhost_len, &in, vq_log, &log,
1151 likely(mergeable) ? UIO_MAXIOV : 1);
1152
1153 if (unlikely(headcount < 0))
1154 goto out;
1155
1156 if (!headcount) {
1157 if (unlikely(busyloop_intr)) {
1158 vhost_poll_queue(&vq->poll);
1159 } else if (unlikely(vhost_enable_notify(&net->dev, vq))) {
1160
1161
1162 vhost_disable_notify(&net->dev, vq);
1163 continue;
1164 }
1165
1166
1167 goto out;
1168 }
1169 busyloop_intr = false;
1170 if (nvq->rx_ring)
1171 msg.msg_control = vhost_net_buf_consume(&nvq->rxq);
1172
1173 if (unlikely(headcount > UIO_MAXIOV)) {
1174 iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1);
1175 err = sock->ops->recvmsg(sock, &msg,
1176 1, MSG_DONTWAIT | MSG_TRUNC);
1177 pr_debug("Discarded rx packet: len %zd\n", sock_len);
1178 continue;
1179 }
1180
1181 iov_iter_init(&msg.msg_iter, READ, vq->iov, in, vhost_len);
1182 fixup = msg.msg_iter;
1183 if (unlikely((vhost_hlen))) {
1184
1185
1186
1187 iov_iter_advance(&msg.msg_iter, vhost_hlen);
1188 }
1189 err = sock->ops->recvmsg(sock, &msg,
1190 sock_len, MSG_DONTWAIT | MSG_TRUNC);
1191
1192
1193
1194 if (unlikely(err != sock_len)) {
1195 pr_debug("Discarded rx packet: "
1196 " len %d, expected %zd\n", err, sock_len);
1197 vhost_discard_vq_desc(vq, headcount);
1198 continue;
1199 }
1200
1201 if (unlikely(vhost_hlen)) {
1202 if (copy_to_iter(&hdr, sizeof(hdr),
1203 &fixup) != sizeof(hdr)) {
1204 vq_err(vq, "Unable to write vnet_hdr "
1205 "at addr %p\n", vq->iov->iov_base);
1206 goto out;
1207 }
1208 } else {
1209
1210
1211
1212 iov_iter_advance(&fixup, sizeof(hdr));
1213 }
1214
1215
1216 num_buffers = cpu_to_vhost16(vq, headcount);
1217 if (likely(mergeable) &&
1218 copy_to_iter(&num_buffers, sizeof num_buffers,
1219 &fixup) != sizeof num_buffers) {
1220 vq_err(vq, "Failed num_buffers write");
1221 vhost_discard_vq_desc(vq, headcount);
1222 goto out;
1223 }
1224 nvq->done_idx += headcount;
1225 if (nvq->done_idx > VHOST_NET_BATCH)
1226 vhost_net_signal_used(nvq);
1227 if (unlikely(vq_log))
1228 vhost_log_write(vq, vq_log, log, vhost_len,
1229 vq->iov, in);
1230 total_len += vhost_len;
1231 } while (likely(!vhost_exceeds_weight(vq, ++recv_pkts, total_len)));
1232
1233 if (unlikely(busyloop_intr))
1234 vhost_poll_queue(&vq->poll);
1235 else if (!sock_len)
1236 vhost_net_enable_vq(net, vq);
1237out:
1238 vhost_net_signal_used(nvq);
1239 mutex_unlock(&vq->mutex);
1240}
1241
1242static void handle_tx_kick(struct vhost_work *work)
1243{
1244 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1245 poll.work);
1246 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
1247
1248 handle_tx(net);
1249}
1250
1251static void handle_rx_kick(struct vhost_work *work)
1252{
1253 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1254 poll.work);
1255 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
1256
1257 handle_rx(net);
1258}
1259
1260static void handle_tx_net(struct vhost_work *work)
1261{
1262 struct vhost_net *net = container_of(work, struct vhost_net,
1263 poll[VHOST_NET_VQ_TX].work);
1264 handle_tx(net);
1265}
1266
1267static void handle_rx_net(struct vhost_work *work)
1268{
1269 struct vhost_net *net = container_of(work, struct vhost_net,
1270 poll[VHOST_NET_VQ_RX].work);
1271 handle_rx(net);
1272}
1273
1274static int vhost_net_open(struct inode *inode, struct file *f)
1275{
1276 struct vhost_net *n;
1277 struct vhost_dev *dev;
1278 struct vhost_virtqueue **vqs;
1279 void **queue;
1280 struct xdp_buff *xdp;
1281 int i;
1282
1283 n = kvmalloc(sizeof *n, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1284 if (!n)
1285 return -ENOMEM;
1286 vqs = kmalloc_array(VHOST_NET_VQ_MAX, sizeof(*vqs), GFP_KERNEL);
1287 if (!vqs) {
1288 kvfree(n);
1289 return -ENOMEM;
1290 }
1291
1292 queue = kmalloc_array(VHOST_NET_BATCH, sizeof(void *),
1293 GFP_KERNEL);
1294 if (!queue) {
1295 kfree(vqs);
1296 kvfree(n);
1297 return -ENOMEM;
1298 }
1299 n->vqs[VHOST_NET_VQ_RX].rxq.queue = queue;
1300
1301 xdp = kmalloc_array(VHOST_NET_BATCH, sizeof(*xdp), GFP_KERNEL);
1302 if (!xdp) {
1303 kfree(vqs);
1304 kvfree(n);
1305 kfree(queue);
1306 return -ENOMEM;
1307 }
1308 n->vqs[VHOST_NET_VQ_TX].xdp = xdp;
1309
1310 dev = &n->dev;
1311 vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq;
1312 vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq;
1313 n->vqs[VHOST_NET_VQ_TX].vq.handle_kick = handle_tx_kick;
1314 n->vqs[VHOST_NET_VQ_RX].vq.handle_kick = handle_rx_kick;
1315 for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
1316 n->vqs[i].ubufs = NULL;
1317 n->vqs[i].ubuf_info = NULL;
1318 n->vqs[i].upend_idx = 0;
1319 n->vqs[i].done_idx = 0;
1320 n->vqs[i].batched_xdp = 0;
1321 n->vqs[i].vhost_hlen = 0;
1322 n->vqs[i].sock_hlen = 0;
1323 n->vqs[i].rx_ring = NULL;
1324 vhost_net_buf_init(&n->vqs[i].rxq);
1325 }
1326 vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX,
1327 UIO_MAXIOV + VHOST_NET_BATCH,
1328 VHOST_NET_PKT_WEIGHT, VHOST_NET_WEIGHT);
1329
1330 vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev);
1331 vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev);
1332
1333 f->private_data = n;
1334 n->page_frag.page = NULL;
1335 n->refcnt_bias = 0;
1336
1337 return 0;
1338}
1339
1340static struct socket *vhost_net_stop_vq(struct vhost_net *n,
1341 struct vhost_virtqueue *vq)
1342{
1343 struct socket *sock;
1344 struct vhost_net_virtqueue *nvq =
1345 container_of(vq, struct vhost_net_virtqueue, vq);
1346
1347 mutex_lock(&vq->mutex);
1348 sock = vq->private_data;
1349 vhost_net_disable_vq(n, vq);
1350 vq->private_data = NULL;
1351 vhost_net_buf_unproduce(nvq);
1352 nvq->rx_ring = NULL;
1353 mutex_unlock(&vq->mutex);
1354 return sock;
1355}
1356
1357static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
1358 struct socket **rx_sock)
1359{
1360 *tx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_TX].vq);
1361 *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq);
1362}
1363
1364static void vhost_net_flush_vq(struct vhost_net *n, int index)
1365{
1366 vhost_poll_flush(n->poll + index);
1367 vhost_poll_flush(&n->vqs[index].vq.poll);
1368}
1369
1370static void vhost_net_flush(struct vhost_net *n)
1371{
1372 vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
1373 vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
1374 if (n->vqs[VHOST_NET_VQ_TX].ubufs) {
1375 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
1376 n->tx_flush = true;
1377 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
1378
1379 vhost_net_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs);
1380 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
1381 n->tx_flush = false;
1382 atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1);
1383 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
1384 }
1385}
1386
1387static int vhost_net_release(struct inode *inode, struct file *f)
1388{
1389 struct vhost_net *n = f->private_data;
1390 struct socket *tx_sock;
1391 struct socket *rx_sock;
1392
1393 vhost_net_stop(n, &tx_sock, &rx_sock);
1394 vhost_net_flush(n);
1395 vhost_dev_stop(&n->dev);
1396 vhost_dev_cleanup(&n->dev);
1397 vhost_net_vq_reset(n);
1398 if (tx_sock)
1399 sockfd_put(tx_sock);
1400 if (rx_sock)
1401 sockfd_put(rx_sock);
1402
1403 synchronize_rcu_bh();
1404
1405
1406 vhost_net_flush(n);
1407 kfree(n->vqs[VHOST_NET_VQ_RX].rxq.queue);
1408 kfree(n->vqs[VHOST_NET_VQ_TX].xdp);
1409 kfree(n->dev.vqs);
1410 if (n->page_frag.page)
1411 __page_frag_cache_drain(n->page_frag.page, n->refcnt_bias);
1412 kvfree(n);
1413 return 0;
1414}
1415
1416static struct socket *get_raw_socket(int fd)
1417{
1418 struct {
1419 struct sockaddr_ll sa;
1420 char buf[MAX_ADDR_LEN];
1421 } uaddr;
1422 int r;
1423 struct socket *sock = sockfd_lookup(fd, &r);
1424
1425 if (!sock)
1426 return ERR_PTR(-ENOTSOCK);
1427
1428
1429 if (sock->sk->sk_type != SOCK_RAW) {
1430 r = -ESOCKTNOSUPPORT;
1431 goto err;
1432 }
1433
1434 r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, 0);
1435 if (r < 0)
1436 goto err;
1437
1438 if (uaddr.sa.sll_family != AF_PACKET) {
1439 r = -EPFNOSUPPORT;
1440 goto err;
1441 }
1442 return sock;
1443err:
1444 sockfd_put(sock);
1445 return ERR_PTR(r);
1446}
1447
1448static struct ptr_ring *get_tap_ptr_ring(int fd)
1449{
1450 struct ptr_ring *ring;
1451 struct file *file = fget(fd);
1452
1453 if (!file)
1454 return NULL;
1455 ring = tun_get_tx_ring(file);
1456 if (!IS_ERR(ring))
1457 goto out;
1458 ring = tap_get_ptr_ring(file);
1459 if (!IS_ERR(ring))
1460 goto out;
1461 ring = NULL;
1462out:
1463 fput(file);
1464 return ring;
1465}
1466
1467static struct socket *get_tap_socket(int fd)
1468{
1469 struct file *file = fget(fd);
1470 struct socket *sock;
1471
1472 if (!file)
1473 return ERR_PTR(-EBADF);
1474 sock = tun_get_socket(file);
1475 if (!IS_ERR(sock))
1476 return sock;
1477 sock = tap_get_socket(file);
1478 if (IS_ERR(sock))
1479 fput(file);
1480 return sock;
1481}
1482
1483static struct socket *get_socket(int fd)
1484{
1485 struct socket *sock;
1486
1487
1488 if (fd == -1)
1489 return NULL;
1490 sock = get_raw_socket(fd);
1491 if (!IS_ERR(sock))
1492 return sock;
1493 sock = get_tap_socket(fd);
1494 if (!IS_ERR(sock))
1495 return sock;
1496 return ERR_PTR(-ENOTSOCK);
1497}
1498
1499static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
1500{
1501 struct socket *sock, *oldsock;
1502 struct vhost_virtqueue *vq;
1503 struct vhost_net_virtqueue *nvq;
1504 struct vhost_net_ubuf_ref *ubufs, *oldubufs = NULL;
1505 int r;
1506
1507 mutex_lock(&n->dev.mutex);
1508 r = vhost_dev_check_owner(&n->dev);
1509 if (r)
1510 goto err;
1511
1512 if (index >= VHOST_NET_VQ_MAX) {
1513 r = -ENOBUFS;
1514 goto err;
1515 }
1516 vq = &n->vqs[index].vq;
1517 nvq = &n->vqs[index];
1518 mutex_lock(&vq->mutex);
1519
1520
1521 if (!vhost_vq_access_ok(vq)) {
1522 r = -EFAULT;
1523 goto err_vq;
1524 }
1525 sock = get_socket(fd);
1526 if (IS_ERR(sock)) {
1527 r = PTR_ERR(sock);
1528 goto err_vq;
1529 }
1530
1531
1532 oldsock = vq->private_data;
1533 if (sock != oldsock) {
1534 ubufs = vhost_net_ubuf_alloc(vq,
1535 sock && vhost_sock_zcopy(sock));
1536 if (IS_ERR(ubufs)) {
1537 r = PTR_ERR(ubufs);
1538 goto err_ubufs;
1539 }
1540
1541 vhost_net_disable_vq(n, vq);
1542 vq->private_data = sock;
1543 vhost_net_buf_unproduce(nvq);
1544 r = vhost_vq_init_access(vq);
1545 if (r)
1546 goto err_used;
1547 r = vhost_net_enable_vq(n, vq);
1548 if (r)
1549 goto err_used;
1550 if (index == VHOST_NET_VQ_RX)
1551 nvq->rx_ring = get_tap_ptr_ring(fd);
1552
1553 oldubufs = nvq->ubufs;
1554 nvq->ubufs = ubufs;
1555
1556 n->tx_packets = 0;
1557 n->tx_zcopy_err = 0;
1558 n->tx_flush = false;
1559 }
1560
1561 mutex_unlock(&vq->mutex);
1562
1563 if (oldubufs) {
1564 vhost_net_ubuf_put_wait_and_free(oldubufs);
1565 mutex_lock(&vq->mutex);
1566 vhost_zerocopy_signal_used(n, vq);
1567 mutex_unlock(&vq->mutex);
1568 }
1569
1570 if (oldsock) {
1571 vhost_net_flush_vq(n, index);
1572 sockfd_put(oldsock);
1573 }
1574
1575 mutex_unlock(&n->dev.mutex);
1576 return 0;
1577
1578err_used:
1579 vq->private_data = oldsock;
1580 vhost_net_enable_vq(n, vq);
1581 if (ubufs)
1582 vhost_net_ubuf_put_wait_and_free(ubufs);
1583err_ubufs:
1584 if (sock)
1585 sockfd_put(sock);
1586err_vq:
1587 mutex_unlock(&vq->mutex);
1588err:
1589 mutex_unlock(&n->dev.mutex);
1590 return r;
1591}
1592
1593static long vhost_net_reset_owner(struct vhost_net *n)
1594{
1595 struct socket *tx_sock = NULL;
1596 struct socket *rx_sock = NULL;
1597 long err;
1598 struct vhost_umem *umem;
1599
1600 mutex_lock(&n->dev.mutex);
1601 err = vhost_dev_check_owner(&n->dev);
1602 if (err)
1603 goto done;
1604 umem = vhost_dev_reset_owner_prepare();
1605 if (!umem) {
1606 err = -ENOMEM;
1607 goto done;
1608 }
1609 vhost_net_stop(n, &tx_sock, &rx_sock);
1610 vhost_net_flush(n);
1611 vhost_dev_stop(&n->dev);
1612 vhost_dev_reset_owner(&n->dev, umem);
1613 vhost_net_vq_reset(n);
1614done:
1615 mutex_unlock(&n->dev.mutex);
1616 if (tx_sock)
1617 sockfd_put(tx_sock);
1618 if (rx_sock)
1619 sockfd_put(rx_sock);
1620 return err;
1621}
1622
1623static int vhost_net_set_backend_features(struct vhost_net *n, u64 features)
1624{
1625 int i;
1626
1627 mutex_lock(&n->dev.mutex);
1628 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
1629 mutex_lock(&n->vqs[i].vq.mutex);
1630 n->vqs[i].vq.acked_backend_features = features;
1631 mutex_unlock(&n->vqs[i].vq.mutex);
1632 }
1633 mutex_unlock(&n->dev.mutex);
1634
1635 return 0;
1636}
1637
1638static int vhost_net_set_features(struct vhost_net *n, u64 features)
1639{
1640 size_t vhost_hlen, sock_hlen, hdr_len;
1641 int i;
1642
1643 hdr_len = (features & ((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
1644 (1ULL << VIRTIO_F_VERSION_1))) ?
1645 sizeof(struct virtio_net_hdr_mrg_rxbuf) :
1646 sizeof(struct virtio_net_hdr);
1647 if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
1648
1649 vhost_hlen = hdr_len;
1650 sock_hlen = 0;
1651 } else {
1652
1653 vhost_hlen = 0;
1654 sock_hlen = hdr_len;
1655 }
1656 mutex_lock(&n->dev.mutex);
1657 if ((features & (1 << VHOST_F_LOG_ALL)) &&
1658 !vhost_log_access_ok(&n->dev))
1659 goto out_unlock;
1660
1661 if ((features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) {
1662 if (vhost_init_device_iotlb(&n->dev, true))
1663 goto out_unlock;
1664 }
1665
1666 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
1667 mutex_lock(&n->vqs[i].vq.mutex);
1668 n->vqs[i].vq.acked_features = features;
1669 n->vqs[i].vhost_hlen = vhost_hlen;
1670 n->vqs[i].sock_hlen = sock_hlen;
1671 mutex_unlock(&n->vqs[i].vq.mutex);
1672 }
1673 mutex_unlock(&n->dev.mutex);
1674 return 0;
1675
1676out_unlock:
1677 mutex_unlock(&n->dev.mutex);
1678 return -EFAULT;
1679}
1680
1681static long vhost_net_set_owner(struct vhost_net *n)
1682{
1683 int r;
1684
1685 mutex_lock(&n->dev.mutex);
1686 if (vhost_dev_has_owner(&n->dev)) {
1687 r = -EBUSY;
1688 goto out;
1689 }
1690 r = vhost_net_set_ubuf_info(n);
1691 if (r)
1692 goto out;
1693 r = vhost_dev_set_owner(&n->dev);
1694 if (r)
1695 vhost_net_clear_ubuf_info(n);
1696 vhost_net_flush(n);
1697out:
1698 mutex_unlock(&n->dev.mutex);
1699 return r;
1700}
1701
1702static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
1703 unsigned long arg)
1704{
1705 struct vhost_net *n = f->private_data;
1706 void __user *argp = (void __user *)arg;
1707 u64 __user *featurep = argp;
1708 struct vhost_vring_file backend;
1709 u64 features;
1710 int r;
1711
1712 switch (ioctl) {
1713 case VHOST_NET_SET_BACKEND:
1714 if (copy_from_user(&backend, argp, sizeof backend))
1715 return -EFAULT;
1716 return vhost_net_set_backend(n, backend.index, backend.fd);
1717 case VHOST_GET_FEATURES:
1718 features = VHOST_NET_FEATURES;
1719 if (copy_to_user(featurep, &features, sizeof features))
1720 return -EFAULT;
1721 return 0;
1722 case VHOST_SET_FEATURES:
1723 if (copy_from_user(&features, featurep, sizeof features))
1724 return -EFAULT;
1725 if (features & ~VHOST_NET_FEATURES)
1726 return -EOPNOTSUPP;
1727 return vhost_net_set_features(n, features);
1728 case VHOST_GET_BACKEND_FEATURES:
1729 features = VHOST_NET_BACKEND_FEATURES;
1730 if (copy_to_user(featurep, &features, sizeof(features)))
1731 return -EFAULT;
1732 return 0;
1733 case VHOST_SET_BACKEND_FEATURES:
1734 if (copy_from_user(&features, featurep, sizeof(features)))
1735 return -EFAULT;
1736 if (features & ~VHOST_NET_BACKEND_FEATURES)
1737 return -EOPNOTSUPP;
1738 return vhost_net_set_backend_features(n, features);
1739 case VHOST_RESET_OWNER:
1740 return vhost_net_reset_owner(n);
1741 case VHOST_SET_OWNER:
1742 return vhost_net_set_owner(n);
1743 default:
1744 mutex_lock(&n->dev.mutex);
1745 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
1746 if (r == -ENOIOCTLCMD)
1747 r = vhost_vring_ioctl(&n->dev, ioctl, argp);
1748 else
1749 vhost_net_flush(n);
1750 mutex_unlock(&n->dev.mutex);
1751 return r;
1752 }
1753}
1754
1755#ifdef CONFIG_COMPAT
1756static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
1757 unsigned long arg)
1758{
1759 return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1760}
1761#endif
1762
1763static ssize_t vhost_net_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1764{
1765 struct file *file = iocb->ki_filp;
1766 struct vhost_net *n = file->private_data;
1767 struct vhost_dev *dev = &n->dev;
1768 int noblock = file->f_flags & O_NONBLOCK;
1769
1770 return vhost_chr_read_iter(dev, to, noblock);
1771}
1772
1773static ssize_t vhost_net_chr_write_iter(struct kiocb *iocb,
1774 struct iov_iter *from)
1775{
1776 struct file *file = iocb->ki_filp;
1777 struct vhost_net *n = file->private_data;
1778 struct vhost_dev *dev = &n->dev;
1779
1780 return vhost_chr_write_iter(dev, from);
1781}
1782
1783static __poll_t vhost_net_chr_poll(struct file *file, poll_table *wait)
1784{
1785 struct vhost_net *n = file->private_data;
1786 struct vhost_dev *dev = &n->dev;
1787
1788 return vhost_chr_poll(file, dev, wait);
1789}
1790
1791static const struct file_operations vhost_net_fops = {
1792 .owner = THIS_MODULE,
1793 .release = vhost_net_release,
1794 .read_iter = vhost_net_chr_read_iter,
1795 .write_iter = vhost_net_chr_write_iter,
1796 .poll = vhost_net_chr_poll,
1797 .unlocked_ioctl = vhost_net_ioctl,
1798#ifdef CONFIG_COMPAT
1799 .compat_ioctl = vhost_net_compat_ioctl,
1800#endif
1801 .open = vhost_net_open,
1802 .llseek = noop_llseek,
1803};
1804
1805static struct miscdevice vhost_net_misc = {
1806 .minor = VHOST_NET_MINOR,
1807 .name = "vhost-net",
1808 .fops = &vhost_net_fops,
1809};
1810
1811static int vhost_net_init(void)
1812{
1813 if (experimental_zcopytx)
1814 vhost_net_enable_zcopy(VHOST_NET_VQ_TX);
1815 return misc_register(&vhost_net_misc);
1816}
1817module_init(vhost_net_init);
1818
1819static void vhost_net_exit(void)
1820{
1821 misc_deregister(&vhost_net_misc);
1822}
1823module_exit(vhost_net_exit);
1824
1825MODULE_VERSION("0.0.1");
1826MODULE_LICENSE("GPL v2");
1827MODULE_AUTHOR("Michael S. Tsirkin");
1828MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1829MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
1830MODULE_ALIAS("devname:vhost-net");
1831