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/rcupdate.h>
19 #include <linux/file.h>
20 #include <linux/slab.h>
22 #include <linux/net.h>
23 #include <linux/if_packet.h>
24 #include <linux/if_arp.h>
25 #include <linux/if_tun.h>
26 #include <linux/if_macvlan.h>
27 #include <linux/if_vlan.h>
33 static int experimental_zcopytx = 1;
34 module_param(experimental_zcopytx, int, 0444);
35 MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
36 " 1 -Enable; 0 - Disable");
38 /* Max number of bytes transferred before requeueing the job.
39 * Using this limit prevents one virtqueue from starving others. */
40 #define VHOST_NET_WEIGHT 0x80000
42 /* MAX number of TX used buffers for outstanding zerocopy */
43 #define VHOST_MAX_PEND 128
44 #define VHOST_GOODCOPY_LEN 256
47 * For transmit, used buffer len is unused; we override it to track buffer
48 * status internally; used for zerocopy tx only.
50 /* Lower device DMA failed */
51 #define VHOST_DMA_FAILED_LEN 3
52 /* Lower device DMA done */
53 #define VHOST_DMA_DONE_LEN 2
54 /* Lower device DMA in progress */
55 #define VHOST_DMA_IN_PROGRESS 1
57 #define VHOST_DMA_CLEAR_LEN 0
59 #define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN)
62 VHOST_NET_FEATURES = VHOST_FEATURES |
63 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
64 (1ULL << VIRTIO_NET_F_MRG_RXBUF),
73 struct vhost_net_ubuf_ref {
75 wait_queue_head_t wait;
76 struct vhost_virtqueue *vq;
79 struct vhost_net_virtqueue {
80 struct vhost_virtqueue vq;
81 /* hdr is used to store the virtio header.
82 * Since each iovec has >= 1 byte length, we never need more than
83 * header length entries to store the header. */
84 struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
87 /* vhost zerocopy support fields below: */
88 /* last used idx for outstanding DMA zerocopy buffers */
90 /* first used idx for DMA done zerocopy buffers */
92 /* an array of userspace buffers info */
93 struct ubuf_info *ubuf_info;
94 /* Reference counting for outstanding ubufs.
95 * Protected by vq mutex. Writers must also take device mutex. */
96 struct vhost_net_ubuf_ref *ubufs;
100 struct vhost_dev dev;
101 struct vhost_net_virtqueue vqs[VHOST_NET_VQ_MAX];
102 struct vhost_poll poll[VHOST_NET_VQ_MAX];
103 /* Number of TX recently submitted.
104 * Protected by tx vq lock. */
106 /* Number of times zerocopy TX recently failed.
107 * Protected by tx vq lock. */
108 unsigned tx_zcopy_err;
109 /* Flush in progress. Protected by tx vq lock. */
113 static unsigned vhost_net_zcopy_mask __read_mostly;
115 static void vhost_net_enable_zcopy(int vq)
117 vhost_net_zcopy_mask |= 0x1 << vq;
120 static void vhost_net_zerocopy_done_signal(struct kref *kref)
122 struct vhost_net_ubuf_ref *ubufs;
124 ubufs = container_of(kref, struct vhost_net_ubuf_ref, kref);
125 wake_up(&ubufs->wait);
128 static struct vhost_net_ubuf_ref *
129 vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy)
131 struct vhost_net_ubuf_ref *ubufs;
132 /* No zero copy backend? Nothing to count. */
135 ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL);
137 return ERR_PTR(-ENOMEM);
138 kref_init(&ubufs->kref);
139 init_waitqueue_head(&ubufs->wait);
144 static void vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
146 kref_put(&ubufs->kref, vhost_net_zerocopy_done_signal);
149 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs)
151 kref_put(&ubufs->kref, vhost_net_zerocopy_done_signal);
152 wait_event(ubufs->wait, !atomic_read(&ubufs->kref.refcount));
155 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs)
157 vhost_net_ubuf_put_and_wait(ubufs);
161 static void vhost_net_clear_ubuf_info(struct vhost_net *n)
165 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
166 kfree(n->vqs[i].ubuf_info);
167 n->vqs[i].ubuf_info = NULL;
171 int vhost_net_set_ubuf_info(struct vhost_net *n)
176 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
177 zcopy = vhost_net_zcopy_mask & (0x1 << i);
180 n->vqs[i].ubuf_info = kmalloc(sizeof(*n->vqs[i].ubuf_info) *
181 UIO_MAXIOV, GFP_KERNEL);
182 if (!n->vqs[i].ubuf_info)
188 vhost_net_clear_ubuf_info(n);
192 void vhost_net_vq_reset(struct vhost_net *n)
196 vhost_net_clear_ubuf_info(n);
198 for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
199 n->vqs[i].done_idx = 0;
200 n->vqs[i].upend_idx = 0;
201 n->vqs[i].ubufs = NULL;
202 n->vqs[i].vhost_hlen = 0;
203 n->vqs[i].sock_hlen = 0;
208 static void vhost_net_tx_packet(struct vhost_net *net)
211 if (net->tx_packets < 1024)
214 net->tx_zcopy_err = 0;
217 static void vhost_net_tx_err(struct vhost_net *net)
222 static bool vhost_net_tx_select_zcopy(struct vhost_net *net)
224 /* TX flush waits for outstanding DMAs to be done.
225 * Don't start new DMAs.
227 return !net->tx_flush &&
228 net->tx_packets / 64 >= net->tx_zcopy_err;
231 static bool vhost_sock_zcopy(struct socket *sock)
233 return unlikely(experimental_zcopytx) &&
234 sock_flag(sock->sk, SOCK_ZEROCOPY);
237 /* Pop first len bytes from iovec. Return number of segments used. */
238 static int move_iovec_hdr(struct iovec *from, struct iovec *to,
239 size_t len, int iov_count)
244 while (len && seg < iov_count) {
245 size = min(from->iov_len, len);
246 to->iov_base = from->iov_base;
248 from->iov_len -= size;
249 from->iov_base += size;
257 /* Copy iovec entries for len bytes from iovec. */
258 static void copy_iovec_hdr(const struct iovec *from, struct iovec *to,
259 size_t len, int iovcount)
264 while (len && seg < iovcount) {
265 size = min(from->iov_len, len);
266 to->iov_base = from->iov_base;
275 /* In case of DMA done not in order in lower device driver for some reason.
276 * upend_idx is used to track end of used idx, done_idx is used to track head
277 * of used idx. Once lower device DMA done contiguously, we will signal KVM
280 static int vhost_zerocopy_signal_used(struct vhost_net *net,
281 struct vhost_virtqueue *vq)
283 struct vhost_net_virtqueue *nvq =
284 container_of(vq, struct vhost_net_virtqueue, vq);
288 for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
289 if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
290 vhost_net_tx_err(net);
291 if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
292 vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
293 vhost_add_used_and_signal(vq->dev, vq,
304 static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success)
306 struct vhost_net_ubuf_ref *ubufs = ubuf->ctx;
307 struct vhost_virtqueue *vq = ubufs->vq;
308 int cnt = atomic_read(&ubufs->kref.refcount);
310 /* set len to mark this desc buffers done DMA */
311 vq->heads[ubuf->desc].len = success ?
312 VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;
313 vhost_net_ubuf_put(ubufs);
316 * Trigger polling thread if guest stopped submitting new buffers:
317 * in this case, the refcount after decrement will eventually reach 1
319 * We also trigger polling periodically after each 16 packets
320 * (the value 16 here is more or less arbitrary, it's tuned to trigger
321 * less than 10% of times).
323 if (cnt <= 2 || !(cnt % 16))
324 vhost_poll_queue(&vq->poll);
327 /* Expects to be always run from workqueue - which acts as
328 * read-size critical section for our kind of RCU. */
329 static void handle_tx(struct vhost_net *net)
331 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
332 struct vhost_virtqueue *vq = &nvq->vq;
335 struct msghdr msg = {
341 .msg_flags = MSG_DONTWAIT,
343 size_t len, total_len = 0;
347 struct vhost_net_ubuf_ref *uninitialized_var(ubufs);
348 bool zcopy, zcopy_used;
350 /* TODO: check that we are running from vhost_worker? */
351 sock = rcu_dereference_check(vq->private_data, 1);
355 mutex_lock(&vq->mutex);
356 vhost_disable_notify(&net->dev, vq);
358 hdr_size = nvq->vhost_hlen;
362 /* Release DMAs done buffers first */
364 vhost_zerocopy_signal_used(net, vq);
366 head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
370 /* On error, stop handling until the next kick. */
371 if (unlikely(head < 0))
373 /* Nothing new? Wait for eventfd to tell us they refilled. */
374 if (head == vq->num) {
377 /* If more outstanding DMAs, queue the work.
378 * Handle upend_idx wrap around
380 num_pends = likely(nvq->upend_idx >= nvq->done_idx) ?
381 (nvq->upend_idx - nvq->done_idx) :
382 (nvq->upend_idx + UIO_MAXIOV -
384 if (unlikely(num_pends > VHOST_MAX_PEND))
386 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
387 vhost_disable_notify(&net->dev, vq);
393 vq_err(vq, "Unexpected descriptor format for TX: "
394 "out %d, int %d\n", out, in);
397 /* Skip header. TODO: support TSO. */
398 s = move_iovec_hdr(vq->iov, nvq->hdr, hdr_size, out);
399 msg.msg_iovlen = out;
400 len = iov_length(vq->iov, out);
403 vq_err(vq, "Unexpected header len for TX: "
404 "%zd expected %zd\n",
405 iov_length(nvq->hdr, s), hdr_size);
408 zcopy_used = zcopy && (len >= VHOST_GOODCOPY_LEN ||
409 nvq->upend_idx != nvq->done_idx);
411 /* use msg_control to pass vhost zerocopy ubuf info to skb */
413 vq->heads[nvq->upend_idx].id = head;
414 if (!vhost_net_tx_select_zcopy(net) ||
415 len < VHOST_GOODCOPY_LEN) {
416 /* copy don't need to wait for DMA done */
417 vq->heads[nvq->upend_idx].len =
419 msg.msg_control = NULL;
420 msg.msg_controllen = 0;
423 struct ubuf_info *ubuf;
424 ubuf = nvq->ubuf_info + nvq->upend_idx;
426 vq->heads[nvq->upend_idx].len =
427 VHOST_DMA_IN_PROGRESS;
428 ubuf->callback = vhost_zerocopy_callback;
429 ubuf->ctx = nvq->ubufs;
430 ubuf->desc = nvq->upend_idx;
431 msg.msg_control = ubuf;
432 msg.msg_controllen = sizeof(ubuf);
434 kref_get(&ubufs->kref);
436 nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
438 msg.msg_control = NULL;
439 /* TODO: Check specific error and bomb out unless ENOBUFS? */
440 err = sock->ops->sendmsg(NULL, sock, &msg, len);
441 if (unlikely(err < 0)) {
444 vhost_net_ubuf_put(ubufs);
445 nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
448 vhost_discard_vq_desc(vq, 1);
452 pr_debug("Truncated TX packet: "
453 " len %d != %zd\n", err, len);
455 vhost_add_used_and_signal(&net->dev, vq, head, 0);
457 vhost_zerocopy_signal_used(net, vq);
459 vhost_net_tx_packet(net);
460 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
461 vhost_poll_queue(&vq->poll);
466 mutex_unlock(&vq->mutex);
469 static int peek_head_len(struct sock *sk)
471 struct sk_buff *head;
475 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
476 head = skb_peek(&sk->sk_receive_queue);
479 if (vlan_tx_tag_present(head))
483 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
487 /* This is a multi-buffer version of vhost_get_desc, that works if
488 * vq has read descriptors only.
489 * @vq - the relevant virtqueue
490 * @datalen - data length we'll be reading
491 * @iovcount - returned count of io vectors we fill
493 * @log_num - log offset
494 * @quota - headcount quota, 1 for big buffer
495 * returns number of buffer heads allocated, negative on error
497 static int get_rx_bufs(struct vhost_virtqueue *vq,
498 struct vring_used_elem *heads,
501 struct vhost_log *log,
505 unsigned int out, in;
511 while (datalen > 0 && headcount < quota) {
512 if (unlikely(seg >= UIO_MAXIOV)) {
516 d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
517 ARRAY_SIZE(vq->iov) - seg, &out,
523 if (unlikely(out || in <= 0)) {
524 vq_err(vq, "unexpected descriptor format for RX: "
525 "out %d, in %d\n", out, in);
533 heads[headcount].id = d;
534 heads[headcount].len = iov_length(vq->iov + seg, in);
535 datalen -= heads[headcount].len;
539 heads[headcount - 1].len += datalen;
545 vhost_discard_vq_desc(vq, headcount);
549 /* Expects to be always run from workqueue - which acts as
550 * read-size critical section for our kind of RCU. */
551 static void handle_rx(struct vhost_net *net)
553 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX];
554 struct vhost_virtqueue *vq = &nvq->vq;
555 unsigned uninitialized_var(in), log;
556 struct vhost_log *vq_log;
557 struct msghdr msg = {
560 .msg_control = NULL, /* FIXME: get and handle RX aux data. */
563 .msg_flags = MSG_DONTWAIT,
565 struct virtio_net_hdr_mrg_rxbuf hdr = {
567 .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
569 size_t total_len = 0;
572 size_t vhost_hlen, sock_hlen;
573 size_t vhost_len, sock_len;
574 /* TODO: check that we are running from vhost_worker? */
575 struct socket *sock = rcu_dereference_check(vq->private_data, 1);
580 mutex_lock(&vq->mutex);
581 vhost_disable_notify(&net->dev, vq);
582 vhost_hlen = nvq->vhost_hlen;
583 sock_hlen = nvq->sock_hlen;
585 vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
587 mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);
589 while ((sock_len = peek_head_len(sock->sk))) {
590 sock_len += sock_hlen;
591 vhost_len = sock_len + vhost_hlen;
592 headcount = get_rx_bufs(vq, vq->heads, vhost_len,
594 likely(mergeable) ? UIO_MAXIOV : 1);
595 /* On error, stop handling until the next kick. */
596 if (unlikely(headcount < 0))
598 /* OK, now we need to know about added descriptors. */
600 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
601 /* They have slipped one in as we were
602 * doing that: check again. */
603 vhost_disable_notify(&net->dev, vq);
606 /* Nothing new? Wait for eventfd to tell us
610 /* We don't need to be notified again. */
611 if (unlikely((vhost_hlen)))
612 /* Skip header. TODO: support TSO. */
613 move_iovec_hdr(vq->iov, nvq->hdr, vhost_hlen, in);
615 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
616 * needed because recvmsg can modify msg_iov. */
617 copy_iovec_hdr(vq->iov, nvq->hdr, sock_hlen, in);
619 err = sock->ops->recvmsg(NULL, sock, &msg,
620 sock_len, MSG_DONTWAIT | MSG_TRUNC);
621 /* Userspace might have consumed the packet meanwhile:
622 * it's not supposed to do this usually, but might be hard
623 * to prevent. Discard data we got (if any) and keep going. */
624 if (unlikely(err != sock_len)) {
625 pr_debug("Discarded rx packet: "
626 " len %d, expected %zd\n", err, sock_len);
627 vhost_discard_vq_desc(vq, headcount);
630 if (unlikely(vhost_hlen) &&
631 memcpy_toiovecend(nvq->hdr, (unsigned char *)&hdr, 0,
633 vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
637 /* TODO: Should check and handle checksum. */
638 if (likely(mergeable) &&
639 memcpy_toiovecend(nvq->hdr, (unsigned char *)&headcount,
640 offsetof(typeof(hdr), num_buffers),
641 sizeof hdr.num_buffers)) {
642 vq_err(vq, "Failed num_buffers write");
643 vhost_discard_vq_desc(vq, headcount);
646 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
648 if (unlikely(vq_log))
649 vhost_log_write(vq, vq_log, log, vhost_len);
650 total_len += vhost_len;
651 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
652 vhost_poll_queue(&vq->poll);
657 mutex_unlock(&vq->mutex);
660 static void handle_tx_kick(struct vhost_work *work)
662 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
664 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
669 static void handle_rx_kick(struct vhost_work *work)
671 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
673 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
678 static void handle_tx_net(struct vhost_work *work)
680 struct vhost_net *net = container_of(work, struct vhost_net,
681 poll[VHOST_NET_VQ_TX].work);
685 static void handle_rx_net(struct vhost_work *work)
687 struct vhost_net *net = container_of(work, struct vhost_net,
688 poll[VHOST_NET_VQ_RX].work);
692 static int vhost_net_open(struct inode *inode, struct file *f)
694 struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
695 struct vhost_dev *dev;
696 struct vhost_virtqueue **vqs;
701 vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
708 vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq;
709 vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq;
710 n->vqs[VHOST_NET_VQ_TX].vq.handle_kick = handle_tx_kick;
711 n->vqs[VHOST_NET_VQ_RX].vq.handle_kick = handle_rx_kick;
712 for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
713 n->vqs[i].ubufs = NULL;
714 n->vqs[i].ubuf_info = NULL;
715 n->vqs[i].upend_idx = 0;
716 n->vqs[i].done_idx = 0;
717 n->vqs[i].vhost_hlen = 0;
718 n->vqs[i].sock_hlen = 0;
720 r = vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);
727 vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
728 vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
735 static void vhost_net_disable_vq(struct vhost_net *n,
736 struct vhost_virtqueue *vq)
738 struct vhost_net_virtqueue *nvq =
739 container_of(vq, struct vhost_net_virtqueue, vq);
740 struct vhost_poll *poll = n->poll + (nvq - n->vqs);
741 if (!vq->private_data)
743 vhost_poll_stop(poll);
746 static int vhost_net_enable_vq(struct vhost_net *n,
747 struct vhost_virtqueue *vq)
749 struct vhost_net_virtqueue *nvq =
750 container_of(vq, struct vhost_net_virtqueue, vq);
751 struct vhost_poll *poll = n->poll + (nvq - n->vqs);
754 sock = rcu_dereference_protected(vq->private_data,
755 lockdep_is_held(&vq->mutex));
759 return vhost_poll_start(poll, sock->file);
762 static struct socket *vhost_net_stop_vq(struct vhost_net *n,
763 struct vhost_virtqueue *vq)
767 mutex_lock(&vq->mutex);
768 sock = rcu_dereference_protected(vq->private_data,
769 lockdep_is_held(&vq->mutex));
770 vhost_net_disable_vq(n, vq);
771 rcu_assign_pointer(vq->private_data, NULL);
772 mutex_unlock(&vq->mutex);
776 static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
777 struct socket **rx_sock)
779 *tx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_TX].vq);
780 *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq);
783 static void vhost_net_flush_vq(struct vhost_net *n, int index)
785 vhost_poll_flush(n->poll + index);
786 vhost_poll_flush(&n->vqs[index].vq.poll);
789 static void vhost_net_flush(struct vhost_net *n)
791 vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
792 vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
793 if (n->vqs[VHOST_NET_VQ_TX].ubufs) {
794 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
796 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
797 /* Wait for all lower device DMAs done. */
798 vhost_net_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs);
799 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
801 kref_init(&n->vqs[VHOST_NET_VQ_TX].ubufs->kref);
802 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
806 static int vhost_net_release(struct inode *inode, struct file *f)
808 struct vhost_net *n = f->private_data;
809 struct socket *tx_sock;
810 struct socket *rx_sock;
812 vhost_net_stop(n, &tx_sock, &rx_sock);
814 vhost_dev_stop(&n->dev);
815 vhost_dev_cleanup(&n->dev, false);
816 vhost_net_vq_reset(n);
821 /* We do an extra flush before freeing memory,
822 * since jobs can re-queue themselves. */
829 static struct socket *get_raw_socket(int fd)
832 struct sockaddr_ll sa;
833 char buf[MAX_ADDR_LEN];
835 int uaddr_len = sizeof uaddr, r;
836 struct socket *sock = sockfd_lookup(fd, &r);
839 return ERR_PTR(-ENOTSOCK);
841 /* Parameter checking */
842 if (sock->sk->sk_type != SOCK_RAW) {
843 r = -ESOCKTNOSUPPORT;
847 r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
852 if (uaddr.sa.sll_family != AF_PACKET) {
862 static struct socket *get_tap_socket(int fd)
864 struct file *file = fget(fd);
868 return ERR_PTR(-EBADF);
869 sock = tun_get_socket(file);
872 sock = macvtap_get_socket(file);
878 static struct socket *get_socket(int fd)
882 /* special case to disable backend */
885 sock = get_raw_socket(fd);
888 sock = get_tap_socket(fd);
891 return ERR_PTR(-ENOTSOCK);
894 static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
896 struct socket *sock, *oldsock;
897 struct vhost_virtqueue *vq;
898 struct vhost_net_virtqueue *nvq;
899 struct vhost_net_ubuf_ref *ubufs, *oldubufs = NULL;
902 mutex_lock(&n->dev.mutex);
903 r = vhost_dev_check_owner(&n->dev);
907 if (index >= VHOST_NET_VQ_MAX) {
911 vq = &n->vqs[index].vq;
912 nvq = &n->vqs[index];
913 mutex_lock(&vq->mutex);
915 /* Verify that ring has been setup correctly. */
916 if (!vhost_vq_access_ok(vq)) {
920 sock = get_socket(fd);
926 /* start polling new socket */
927 oldsock = rcu_dereference_protected(vq->private_data,
928 lockdep_is_held(&vq->mutex));
929 if (sock != oldsock) {
930 ubufs = vhost_net_ubuf_alloc(vq,
931 sock && vhost_sock_zcopy(sock));
937 vhost_net_disable_vq(n, vq);
938 rcu_assign_pointer(vq->private_data, sock);
939 r = vhost_init_used(vq);
942 r = vhost_net_enable_vq(n, vq);
946 oldubufs = nvq->ubufs;
954 mutex_unlock(&vq->mutex);
957 vhost_net_ubuf_put_wait_and_free(oldubufs);
958 mutex_lock(&vq->mutex);
959 vhost_zerocopy_signal_used(n, vq);
960 mutex_unlock(&vq->mutex);
964 vhost_net_flush_vq(n, index);
968 mutex_unlock(&n->dev.mutex);
972 rcu_assign_pointer(vq->private_data, oldsock);
973 vhost_net_enable_vq(n, vq);
975 vhost_net_ubuf_put_wait_and_free(ubufs);
979 mutex_unlock(&vq->mutex);
981 mutex_unlock(&n->dev.mutex);
985 static long vhost_net_reset_owner(struct vhost_net *n)
987 struct socket *tx_sock = NULL;
988 struct socket *rx_sock = NULL;
990 struct vhost_memory *memory;
992 mutex_lock(&n->dev.mutex);
993 err = vhost_dev_check_owner(&n->dev);
996 memory = vhost_dev_reset_owner_prepare();
1001 vhost_net_stop(n, &tx_sock, &rx_sock);
1003 vhost_dev_reset_owner(&n->dev, memory);
1004 vhost_net_vq_reset(n);
1006 mutex_unlock(&n->dev.mutex);
1008 fput(tx_sock->file);
1010 fput(rx_sock->file);
1014 static int vhost_net_set_features(struct vhost_net *n, u64 features)
1016 size_t vhost_hlen, sock_hlen, hdr_len;
1019 hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
1020 sizeof(struct virtio_net_hdr_mrg_rxbuf) :
1021 sizeof(struct virtio_net_hdr);
1022 if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
1023 /* vhost provides vnet_hdr */
1024 vhost_hlen = hdr_len;
1027 /* socket provides vnet_hdr */
1029 sock_hlen = hdr_len;
1031 mutex_lock(&n->dev.mutex);
1032 if ((features & (1 << VHOST_F_LOG_ALL)) &&
1033 !vhost_log_access_ok(&n->dev)) {
1034 mutex_unlock(&n->dev.mutex);
1037 n->dev.acked_features = features;
1039 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
1040 mutex_lock(&n->vqs[i].vq.mutex);
1041 n->vqs[i].vhost_hlen = vhost_hlen;
1042 n->vqs[i].sock_hlen = sock_hlen;
1043 mutex_unlock(&n->vqs[i].vq.mutex);
1046 mutex_unlock(&n->dev.mutex);
1050 static long vhost_net_set_owner(struct vhost_net *n)
1054 mutex_lock(&n->dev.mutex);
1055 if (vhost_dev_has_owner(&n->dev)) {
1059 r = vhost_net_set_ubuf_info(n);
1062 r = vhost_dev_set_owner(&n->dev);
1064 vhost_net_clear_ubuf_info(n);
1067 mutex_unlock(&n->dev.mutex);
1071 static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
1074 struct vhost_net *n = f->private_data;
1075 void __user *argp = (void __user *)arg;
1076 u64 __user *featurep = argp;
1077 struct vhost_vring_file backend;
1082 case VHOST_NET_SET_BACKEND:
1083 if (copy_from_user(&backend, argp, sizeof backend))
1085 return vhost_net_set_backend(n, backend.index, backend.fd);
1086 case VHOST_GET_FEATURES:
1087 features = VHOST_NET_FEATURES;
1088 if (copy_to_user(featurep, &features, sizeof features))
1091 case VHOST_SET_FEATURES:
1092 if (copy_from_user(&features, featurep, sizeof features))
1094 if (features & ~VHOST_NET_FEATURES)
1096 return vhost_net_set_features(n, features);
1097 case VHOST_RESET_OWNER:
1098 return vhost_net_reset_owner(n);
1099 case VHOST_SET_OWNER:
1100 return vhost_net_set_owner(n);
1102 mutex_lock(&n->dev.mutex);
1103 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
1104 if (r == -ENOIOCTLCMD)
1105 r = vhost_vring_ioctl(&n->dev, ioctl, argp);
1108 mutex_unlock(&n->dev.mutex);
1113 #ifdef CONFIG_COMPAT
1114 static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
1117 return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1121 static const struct file_operations vhost_net_fops = {
1122 .owner = THIS_MODULE,
1123 .release = vhost_net_release,
1124 .unlocked_ioctl = vhost_net_ioctl,
1125 #ifdef CONFIG_COMPAT
1126 .compat_ioctl = vhost_net_compat_ioctl,
1128 .open = vhost_net_open,
1129 .llseek = noop_llseek,
1132 static struct miscdevice vhost_net_misc = {
1133 .minor = VHOST_NET_MINOR,
1134 .name = "vhost-net",
1135 .fops = &vhost_net_fops,
1138 static int vhost_net_init(void)
1140 if (experimental_zcopytx)
1141 vhost_net_enable_zcopy(VHOST_NET_VQ_TX);
1142 return misc_register(&vhost_net_misc);
1144 module_init(vhost_net_init);
1146 static void vhost_net_exit(void)
1148 misc_deregister(&vhost_net_misc);
1150 module_exit(vhost_net_exit);
1152 MODULE_VERSION("0.0.1");
1153 MODULE_LICENSE("GPL v2");
1154 MODULE_AUTHOR("Michael S. Tsirkin");
1155 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1156 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
1157 MODULE_ALIAS("devname:vhost-net");