1 /* Copyright (C) 2009 Red Hat, Inc.
2 * Author: Michael S. Tsirkin <mst@redhat.com>
4 * This work is licensed under the terms of the GNU GPL, version 2.
6 * virtio-net server in host kernel.
9 #include <linux/compat.h>
10 #include <linux/eventfd.h>
11 #include <linux/vhost.h>
12 #include <linux/virtio_net.h>
13 #include <linux/miscdevice.h>
14 #include <linux/module.h>
15 #include <linux/moduleparam.h>
16 #include <linux/mutex.h>
17 #include <linux/workqueue.h>
18 #include <linux/file.h>
19 #include <linux/slab.h>
21 #include <linux/net.h>
22 #include <linux/if_packet.h>
23 #include <linux/if_arp.h>
24 #include <linux/if_tun.h>
25 #include <linux/if_macvlan.h>
26 #include <linux/if_vlan.h>
32 static int experimental_zcopytx = 1;
33 module_param(experimental_zcopytx, int, 0444);
34 MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
35 " 1 -Enable; 0 - Disable");
37 /* Max number of bytes transferred before requeueing the job.
38 * Using this limit prevents one virtqueue from starving others. */
39 #define VHOST_NET_WEIGHT 0x80000
41 /* MAX number of TX used buffers for outstanding zerocopy */
42 #define VHOST_MAX_PEND 128
43 #define VHOST_GOODCOPY_LEN 256
46 * For transmit, used buffer len is unused; we override it to track buffer
47 * status internally; used for zerocopy tx only.
49 /* Lower device DMA failed */
50 #define VHOST_DMA_FAILED_LEN 3
51 /* Lower device DMA done */
52 #define VHOST_DMA_DONE_LEN 2
53 /* Lower device DMA in progress */
54 #define VHOST_DMA_IN_PROGRESS 1
56 #define VHOST_DMA_CLEAR_LEN 0
58 #define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN)
61 VHOST_NET_FEATURES = VHOST_FEATURES |
62 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
63 (1ULL << VIRTIO_NET_F_MRG_RXBUF),
72 struct vhost_net_ubuf_ref {
73 /* refcount follows semantics similar to kref:
74 * 0: object is released
75 * 1: no outstanding ubufs
76 * >1: outstanding ubufs
79 wait_queue_head_t wait;
80 struct vhost_virtqueue *vq;
83 struct vhost_net_virtqueue {
84 struct vhost_virtqueue vq;
85 /* hdr is used to store the virtio header.
86 * Since each iovec has >= 1 byte length, we never need more than
87 * header length entries to store the header. */
88 struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
91 /* vhost zerocopy support fields below: */
92 /* last used idx for outstanding DMA zerocopy buffers */
94 /* first used idx for DMA done zerocopy buffers */
96 /* an array of userspace buffers info */
97 struct ubuf_info *ubuf_info;
98 /* Reference counting for outstanding ubufs.
99 * Protected by vq mutex. Writers must also take device mutex. */
100 struct vhost_net_ubuf_ref *ubufs;
104 struct vhost_dev dev;
105 struct vhost_net_virtqueue vqs[VHOST_NET_VQ_MAX];
106 struct vhost_poll poll[VHOST_NET_VQ_MAX];
107 /* Number of TX recently submitted.
108 * Protected by tx vq lock. */
110 /* Number of times zerocopy TX recently failed.
111 * Protected by tx vq lock. */
112 unsigned tx_zcopy_err;
113 /* Flush in progress. Protected by tx vq lock. */
117 static unsigned vhost_net_zcopy_mask __read_mostly;
119 static void vhost_net_enable_zcopy(int vq)
121 vhost_net_zcopy_mask |= 0x1 << vq;
124 static struct vhost_net_ubuf_ref *
125 vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy)
127 struct vhost_net_ubuf_ref *ubufs;
128 /* No zero copy backend? Nothing to count. */
131 ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL);
133 return ERR_PTR(-ENOMEM);
134 atomic_set(&ubufs->refcount, 1);
135 init_waitqueue_head(&ubufs->wait);
140 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
142 int r = atomic_sub_return(1, &ubufs->refcount);
144 wake_up(&ubufs->wait);
148 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs)
150 vhost_net_ubuf_put(ubufs);
151 wait_event(ubufs->wait, !atomic_read(&ubufs->refcount));
154 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs)
156 vhost_net_ubuf_put_and_wait(ubufs);
160 static void vhost_net_clear_ubuf_info(struct vhost_net *n)
164 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
165 kfree(n->vqs[i].ubuf_info);
166 n->vqs[i].ubuf_info = NULL;
170 static int vhost_net_set_ubuf_info(struct vhost_net *n)
175 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
176 zcopy = vhost_net_zcopy_mask & (0x1 << i);
179 n->vqs[i].ubuf_info = kmalloc(sizeof(*n->vqs[i].ubuf_info) *
180 UIO_MAXIOV, GFP_KERNEL);
181 if (!n->vqs[i].ubuf_info)
187 vhost_net_clear_ubuf_info(n);
191 static void vhost_net_vq_reset(struct vhost_net *n)
195 vhost_net_clear_ubuf_info(n);
197 for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
198 n->vqs[i].done_idx = 0;
199 n->vqs[i].upend_idx = 0;
200 n->vqs[i].ubufs = NULL;
201 n->vqs[i].vhost_hlen = 0;
202 n->vqs[i].sock_hlen = 0;
207 static void vhost_net_tx_packet(struct vhost_net *net)
210 if (net->tx_packets < 1024)
213 net->tx_zcopy_err = 0;
216 static void vhost_net_tx_err(struct vhost_net *net)
221 static bool vhost_net_tx_select_zcopy(struct vhost_net *net)
223 /* TX flush waits for outstanding DMAs to be done.
224 * Don't start new DMAs.
226 return !net->tx_flush &&
227 net->tx_packets / 64 >= net->tx_zcopy_err;
230 static bool vhost_sock_zcopy(struct socket *sock)
232 return unlikely(experimental_zcopytx) &&
233 sock_flag(sock->sk, SOCK_ZEROCOPY);
236 /* Pop first len bytes from iovec. Return number of segments used. */
237 static int move_iovec_hdr(struct iovec *from, struct iovec *to,
238 size_t len, int iov_count)
243 while (len && seg < iov_count) {
244 size = min(from->iov_len, len);
245 to->iov_base = from->iov_base;
247 from->iov_len -= size;
248 from->iov_base += size;
256 /* Copy iovec entries for len bytes from iovec. */
257 static void copy_iovec_hdr(const struct iovec *from, struct iovec *to,
258 size_t len, int iovcount)
263 while (len && seg < iovcount) {
264 size = min(from->iov_len, len);
265 to->iov_base = from->iov_base;
274 /* In case of DMA done not in order in lower device driver for some reason.
275 * upend_idx is used to track end of used idx, done_idx is used to track head
276 * of used idx. Once lower device DMA done contiguously, we will signal KVM
279 static void vhost_zerocopy_signal_used(struct vhost_net *net,
280 struct vhost_virtqueue *vq)
282 struct vhost_net_virtqueue *nvq =
283 container_of(vq, struct vhost_net_virtqueue, vq);
287 for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
288 if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
289 vhost_net_tx_err(net);
290 if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
291 vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
297 add = min(UIO_MAXIOV - nvq->done_idx, j);
298 vhost_add_used_and_signal_n(vq->dev, vq,
299 &vq->heads[nvq->done_idx], add);
300 nvq->done_idx = (nvq->done_idx + add) % UIO_MAXIOV;
305 static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success)
307 struct vhost_net_ubuf_ref *ubufs = ubuf->ctx;
308 struct vhost_virtqueue *vq = ubufs->vq;
313 /* set len to mark this desc buffers done DMA */
314 vq->heads[ubuf->desc].len = success ?
315 VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;
316 cnt = vhost_net_ubuf_put(ubufs);
319 * Trigger polling thread if guest stopped submitting new buffers:
320 * in this case, the refcount after decrement will eventually reach 1.
321 * We also trigger polling periodically after each 16 packets
322 * (the value 16 here is more or less arbitrary, it's tuned to trigger
323 * less than 10% of times).
325 if (cnt <= 1 || !(cnt % 16))
326 vhost_poll_queue(&vq->poll);
328 rcu_read_unlock_bh();
331 /* Expects to be always run from workqueue - which acts as
332 * read-size critical section for our kind of RCU. */
333 static void handle_tx(struct vhost_net *net)
335 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
336 struct vhost_virtqueue *vq = &nvq->vq;
339 struct msghdr msg = {
345 .msg_flags = MSG_DONTWAIT,
347 size_t len, total_len = 0;
351 struct vhost_net_ubuf_ref *uninitialized_var(ubufs);
352 bool zcopy, zcopy_used;
354 mutex_lock(&vq->mutex);
355 sock = vq->private_data;
359 vhost_disable_notify(&net->dev, vq);
361 hdr_size = nvq->vhost_hlen;
365 /* Release DMAs done buffers first */
367 vhost_zerocopy_signal_used(net, vq);
369 /* If more outstanding DMAs, queue the work.
370 * Handle upend_idx wrap around
372 if (unlikely((nvq->upend_idx + vq->num - VHOST_MAX_PEND)
373 % UIO_MAXIOV == nvq->done_idx))
376 head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
380 /* On error, stop handling until the next kick. */
381 if (unlikely(head < 0))
383 /* Nothing new? Wait for eventfd to tell us they refilled. */
384 if (head == vq->num) {
385 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
386 vhost_disable_notify(&net->dev, vq);
392 vq_err(vq, "Unexpected descriptor format for TX: "
393 "out %d, int %d\n", out, in);
396 /* Skip header. TODO: support TSO. */
397 s = move_iovec_hdr(vq->iov, nvq->hdr, hdr_size, out);
398 msg.msg_iovlen = out;
399 len = iov_length(vq->iov, out);
402 vq_err(vq, "Unexpected header len for TX: "
403 "%zd expected %zd\n",
404 iov_length(nvq->hdr, s), hdr_size);
408 zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN
409 && (nvq->upend_idx + 1) % UIO_MAXIOV !=
411 && vhost_net_tx_select_zcopy(net);
413 /* use msg_control to pass vhost zerocopy ubuf info to skb */
415 struct ubuf_info *ubuf;
416 ubuf = nvq->ubuf_info + nvq->upend_idx;
418 vq->heads[nvq->upend_idx].id = head;
419 vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
420 ubuf->callback = vhost_zerocopy_callback;
421 ubuf->ctx = nvq->ubufs;
422 ubuf->desc = nvq->upend_idx;
423 msg.msg_control = ubuf;
424 msg.msg_controllen = sizeof(ubuf);
426 atomic_inc(&ubufs->refcount);
427 nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
429 msg.msg_control = NULL;
432 /* TODO: Check specific error and bomb out unless ENOBUFS? */
433 err = sock->ops->sendmsg(NULL, sock, &msg, len);
434 if (unlikely(err < 0)) {
436 vhost_net_ubuf_put(ubufs);
437 nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
440 vhost_discard_vq_desc(vq, 1);
444 pr_debug("Truncated TX packet: "
445 " len %d != %zd\n", err, len);
447 vhost_add_used_and_signal(&net->dev, vq, head, 0);
449 vhost_zerocopy_signal_used(net, vq);
451 vhost_net_tx_packet(net);
452 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
453 vhost_poll_queue(&vq->poll);
458 mutex_unlock(&vq->mutex);
461 static int peek_head_len(struct sock *sk)
463 struct sk_buff *head;
467 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
468 head = skb_peek(&sk->sk_receive_queue);
471 if (vlan_tx_tag_present(head))
475 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
479 /* This is a multi-buffer version of vhost_get_desc, that works if
480 * vq has read descriptors only.
481 * @vq - the relevant virtqueue
482 * @datalen - data length we'll be reading
483 * @iovcount - returned count of io vectors we fill
485 * @log_num - log offset
486 * @quota - headcount quota, 1 for big buffer
487 * returns number of buffer heads allocated, negative on error
489 static int get_rx_bufs(struct vhost_virtqueue *vq,
490 struct vring_used_elem *heads,
493 struct vhost_log *log,
497 unsigned int out, in;
503 while (datalen > 0 && headcount < quota) {
504 if (unlikely(seg >= UIO_MAXIOV)) {
508 r = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
509 ARRAY_SIZE(vq->iov) - seg, &out,
519 if (unlikely(out || in <= 0)) {
520 vq_err(vq, "unexpected descriptor format for RX: "
521 "out %d, in %d\n", out, in);
529 heads[headcount].id = d;
530 heads[headcount].len = iov_length(vq->iov + seg, in);
531 datalen -= heads[headcount].len;
535 heads[headcount - 1].len += datalen;
541 if (unlikely(datalen > 0)) {
547 vhost_discard_vq_desc(vq, headcount);
551 /* Expects to be always run from workqueue - which acts as
552 * read-size critical section for our kind of RCU. */
553 static void handle_rx(struct vhost_net *net)
555 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX];
556 struct vhost_virtqueue *vq = &nvq->vq;
557 unsigned uninitialized_var(in), log;
558 struct vhost_log *vq_log;
559 struct msghdr msg = {
562 .msg_control = NULL, /* FIXME: get and handle RX aux data. */
565 .msg_flags = MSG_DONTWAIT,
567 struct virtio_net_hdr_mrg_rxbuf hdr = {
569 .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
571 size_t total_len = 0;
574 size_t vhost_hlen, sock_hlen;
575 size_t vhost_len, sock_len;
578 mutex_lock(&vq->mutex);
579 sock = vq->private_data;
582 vhost_disable_notify(&net->dev, vq);
584 vhost_hlen = nvq->vhost_hlen;
585 sock_hlen = nvq->sock_hlen;
587 vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
589 mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);
591 while ((sock_len = peek_head_len(sock->sk))) {
592 sock_len += sock_hlen;
593 vhost_len = sock_len + vhost_hlen;
594 headcount = get_rx_bufs(vq, vq->heads, vhost_len,
596 likely(mergeable) ? UIO_MAXIOV : 1);
597 /* On error, stop handling until the next kick. */
598 if (unlikely(headcount < 0))
600 /* On overrun, truncate and discard */
601 if (unlikely(headcount > UIO_MAXIOV)) {
603 err = sock->ops->recvmsg(NULL, sock, &msg,
604 1, MSG_DONTWAIT | MSG_TRUNC);
605 pr_debug("Discarded rx packet: len %zd\n", sock_len);
608 /* OK, now we need to know about added descriptors. */
610 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
611 /* They have slipped one in as we were
612 * doing that: check again. */
613 vhost_disable_notify(&net->dev, vq);
616 /* Nothing new? Wait for eventfd to tell us
620 /* We don't need to be notified again. */
621 if (unlikely((vhost_hlen)))
622 /* Skip header. TODO: support TSO. */
623 move_iovec_hdr(vq->iov, nvq->hdr, vhost_hlen, in);
625 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
626 * needed because recvmsg can modify msg_iov. */
627 copy_iovec_hdr(vq->iov, nvq->hdr, sock_hlen, in);
629 err = sock->ops->recvmsg(NULL, sock, &msg,
630 sock_len, MSG_DONTWAIT | MSG_TRUNC);
631 /* Userspace might have consumed the packet meanwhile:
632 * it's not supposed to do this usually, but might be hard
633 * to prevent. Discard data we got (if any) and keep going. */
634 if (unlikely(err != sock_len)) {
635 pr_debug("Discarded rx packet: "
636 " len %d, expected %zd\n", err, sock_len);
637 vhost_discard_vq_desc(vq, headcount);
640 if (unlikely(vhost_hlen) &&
641 memcpy_toiovecend(nvq->hdr, (unsigned char *)&hdr, 0,
643 vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
647 /* TODO: Should check and handle checksum. */
648 if (likely(mergeable) &&
649 memcpy_toiovecend(nvq->hdr, (unsigned char *)&headcount,
650 offsetof(typeof(hdr), num_buffers),
651 sizeof hdr.num_buffers)) {
652 vq_err(vq, "Failed num_buffers write");
653 vhost_discard_vq_desc(vq, headcount);
656 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
658 if (unlikely(vq_log))
659 vhost_log_write(vq, vq_log, log, vhost_len);
660 total_len += vhost_len;
661 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
662 vhost_poll_queue(&vq->poll);
667 mutex_unlock(&vq->mutex);
670 static void handle_tx_kick(struct vhost_work *work)
672 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
674 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
679 static void handle_rx_kick(struct vhost_work *work)
681 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
683 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
688 static void handle_tx_net(struct vhost_work *work)
690 struct vhost_net *net = container_of(work, struct vhost_net,
691 poll[VHOST_NET_VQ_TX].work);
695 static void handle_rx_net(struct vhost_work *work)
697 struct vhost_net *net = container_of(work, struct vhost_net,
698 poll[VHOST_NET_VQ_RX].work);
702 static int vhost_net_open(struct inode *inode, struct file *f)
704 struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
705 struct vhost_dev *dev;
706 struct vhost_virtqueue **vqs;
711 vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
718 vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq;
719 vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq;
720 n->vqs[VHOST_NET_VQ_TX].vq.handle_kick = handle_tx_kick;
721 n->vqs[VHOST_NET_VQ_RX].vq.handle_kick = handle_rx_kick;
722 for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
723 n->vqs[i].ubufs = NULL;
724 n->vqs[i].ubuf_info = NULL;
725 n->vqs[i].upend_idx = 0;
726 n->vqs[i].done_idx = 0;
727 n->vqs[i].vhost_hlen = 0;
728 n->vqs[i].sock_hlen = 0;
730 vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);
732 vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
733 vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
740 static void vhost_net_disable_vq(struct vhost_net *n,
741 struct vhost_virtqueue *vq)
743 struct vhost_net_virtqueue *nvq =
744 container_of(vq, struct vhost_net_virtqueue, vq);
745 struct vhost_poll *poll = n->poll + (nvq - n->vqs);
746 if (!vq->private_data)
748 vhost_poll_stop(poll);
751 static int vhost_net_enable_vq(struct vhost_net *n,
752 struct vhost_virtqueue *vq)
754 struct vhost_net_virtqueue *nvq =
755 container_of(vq, struct vhost_net_virtqueue, vq);
756 struct vhost_poll *poll = n->poll + (nvq - n->vqs);
759 sock = vq->private_data;
763 return vhost_poll_start(poll, sock->file);
766 static struct socket *vhost_net_stop_vq(struct vhost_net *n,
767 struct vhost_virtqueue *vq)
771 mutex_lock(&vq->mutex);
772 sock = vq->private_data;
773 vhost_net_disable_vq(n, vq);
774 vq->private_data = NULL;
775 mutex_unlock(&vq->mutex);
779 static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
780 struct socket **rx_sock)
782 *tx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_TX].vq);
783 *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq);
786 static void vhost_net_flush_vq(struct vhost_net *n, int index)
788 vhost_poll_flush(n->poll + index);
789 vhost_poll_flush(&n->vqs[index].vq.poll);
792 static void vhost_net_flush(struct vhost_net *n)
794 vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
795 vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
796 if (n->vqs[VHOST_NET_VQ_TX].ubufs) {
797 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
799 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
800 /* Wait for all lower device DMAs done. */
801 vhost_net_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs);
802 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
804 atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1);
805 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
809 static int vhost_net_release(struct inode *inode, struct file *f)
811 struct vhost_net *n = f->private_data;
812 struct socket *tx_sock;
813 struct socket *rx_sock;
815 vhost_net_stop(n, &tx_sock, &rx_sock);
817 vhost_dev_stop(&n->dev);
818 vhost_dev_cleanup(&n->dev, false);
819 vhost_net_vq_reset(n);
824 /* Make sure no callbacks are outstanding */
825 synchronize_rcu_bh();
826 /* We do an extra flush before freeing memory,
827 * since jobs can re-queue themselves. */
834 static struct socket *get_raw_socket(int fd)
837 struct sockaddr_ll sa;
838 char buf[MAX_ADDR_LEN];
840 int uaddr_len = sizeof uaddr, r;
841 struct socket *sock = sockfd_lookup(fd, &r);
844 return ERR_PTR(-ENOTSOCK);
846 /* Parameter checking */
847 if (sock->sk->sk_type != SOCK_RAW) {
848 r = -ESOCKTNOSUPPORT;
852 r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
857 if (uaddr.sa.sll_family != AF_PACKET) {
867 static struct socket *get_tap_socket(int fd)
869 struct file *file = fget(fd);
873 return ERR_PTR(-EBADF);
874 sock = tun_get_socket(file);
877 sock = macvtap_get_socket(file);
883 static struct socket *get_socket(int fd)
887 /* special case to disable backend */
890 sock = get_raw_socket(fd);
893 sock = get_tap_socket(fd);
896 return ERR_PTR(-ENOTSOCK);
899 static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
901 struct socket *sock, *oldsock;
902 struct vhost_virtqueue *vq;
903 struct vhost_net_virtqueue *nvq;
904 struct vhost_net_ubuf_ref *ubufs, *oldubufs = NULL;
907 mutex_lock(&n->dev.mutex);
908 r = vhost_dev_check_owner(&n->dev);
912 if (index >= VHOST_NET_VQ_MAX) {
916 vq = &n->vqs[index].vq;
917 nvq = &n->vqs[index];
918 mutex_lock(&vq->mutex);
920 /* Verify that ring has been setup correctly. */
921 if (!vhost_vq_access_ok(vq)) {
925 sock = get_socket(fd);
931 /* start polling new socket */
932 oldsock = vq->private_data;
933 if (sock != oldsock) {
934 ubufs = vhost_net_ubuf_alloc(vq,
935 sock && vhost_sock_zcopy(sock));
941 vhost_net_disable_vq(n, vq);
942 vq->private_data = sock;
943 r = vhost_init_used(vq);
946 r = vhost_net_enable_vq(n, vq);
950 oldubufs = nvq->ubufs;
958 mutex_unlock(&vq->mutex);
961 vhost_net_ubuf_put_wait_and_free(oldubufs);
962 mutex_lock(&vq->mutex);
963 vhost_zerocopy_signal_used(n, vq);
964 mutex_unlock(&vq->mutex);
968 vhost_net_flush_vq(n, index);
972 mutex_unlock(&n->dev.mutex);
976 vq->private_data = oldsock;
977 vhost_net_enable_vq(n, vq);
979 vhost_net_ubuf_put_wait_and_free(ubufs);
983 mutex_unlock(&vq->mutex);
985 mutex_unlock(&n->dev.mutex);
989 static long vhost_net_reset_owner(struct vhost_net *n)
991 struct socket *tx_sock = NULL;
992 struct socket *rx_sock = NULL;
994 struct vhost_memory *memory;
996 mutex_lock(&n->dev.mutex);
997 err = vhost_dev_check_owner(&n->dev);
1000 memory = vhost_dev_reset_owner_prepare();
1005 vhost_net_stop(n, &tx_sock, &rx_sock);
1007 vhost_dev_reset_owner(&n->dev, memory);
1008 vhost_net_vq_reset(n);
1010 mutex_unlock(&n->dev.mutex);
1012 sockfd_put(tx_sock);
1014 sockfd_put(rx_sock);
1018 static int vhost_net_set_features(struct vhost_net *n, u64 features)
1020 size_t vhost_hlen, sock_hlen, hdr_len;
1023 hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
1024 sizeof(struct virtio_net_hdr_mrg_rxbuf) :
1025 sizeof(struct virtio_net_hdr);
1026 if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
1027 /* vhost provides vnet_hdr */
1028 vhost_hlen = hdr_len;
1031 /* socket provides vnet_hdr */
1033 sock_hlen = hdr_len;
1035 mutex_lock(&n->dev.mutex);
1036 if ((features & (1 << VHOST_F_LOG_ALL)) &&
1037 !vhost_log_access_ok(&n->dev)) {
1038 mutex_unlock(&n->dev.mutex);
1041 n->dev.acked_features = features;
1043 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
1044 mutex_lock(&n->vqs[i].vq.mutex);
1045 n->vqs[i].vhost_hlen = vhost_hlen;
1046 n->vqs[i].sock_hlen = sock_hlen;
1047 mutex_unlock(&n->vqs[i].vq.mutex);
1050 mutex_unlock(&n->dev.mutex);
1054 static long vhost_net_set_owner(struct vhost_net *n)
1058 mutex_lock(&n->dev.mutex);
1059 if (vhost_dev_has_owner(&n->dev)) {
1063 r = vhost_net_set_ubuf_info(n);
1066 r = vhost_dev_set_owner(&n->dev);
1068 vhost_net_clear_ubuf_info(n);
1071 mutex_unlock(&n->dev.mutex);
1075 static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
1078 struct vhost_net *n = f->private_data;
1079 void __user *argp = (void __user *)arg;
1080 u64 __user *featurep = argp;
1081 struct vhost_vring_file backend;
1086 case VHOST_NET_SET_BACKEND:
1087 if (copy_from_user(&backend, argp, sizeof backend))
1089 return vhost_net_set_backend(n, backend.index, backend.fd);
1090 case VHOST_GET_FEATURES:
1091 features = VHOST_NET_FEATURES;
1092 if (copy_to_user(featurep, &features, sizeof features))
1095 case VHOST_SET_FEATURES:
1096 if (copy_from_user(&features, featurep, sizeof features))
1098 if (features & ~VHOST_NET_FEATURES)
1100 return vhost_net_set_features(n, features);
1101 case VHOST_RESET_OWNER:
1102 return vhost_net_reset_owner(n);
1103 case VHOST_SET_OWNER:
1104 return vhost_net_set_owner(n);
1106 mutex_lock(&n->dev.mutex);
1107 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
1108 if (r == -ENOIOCTLCMD)
1109 r = vhost_vring_ioctl(&n->dev, ioctl, argp);
1112 mutex_unlock(&n->dev.mutex);
1117 #ifdef CONFIG_COMPAT
1118 static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
1121 return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1125 static const struct file_operations vhost_net_fops = {
1126 .owner = THIS_MODULE,
1127 .release = vhost_net_release,
1128 .unlocked_ioctl = vhost_net_ioctl,
1129 #ifdef CONFIG_COMPAT
1130 .compat_ioctl = vhost_net_compat_ioctl,
1132 .open = vhost_net_open,
1133 .llseek = noop_llseek,
1136 static struct miscdevice vhost_net_misc = {
1137 .minor = VHOST_NET_MINOR,
1138 .name = "vhost-net",
1139 .fops = &vhost_net_fops,
1142 static int vhost_net_init(void)
1144 if (experimental_zcopytx)
1145 vhost_net_enable_zcopy(VHOST_NET_VQ_TX);
1146 return misc_register(&vhost_net_misc);
1148 module_init(vhost_net_init);
1150 static void vhost_net_exit(void)
1152 misc_deregister(&vhost_net_misc);
1154 module_exit(vhost_net_exit);
1156 MODULE_VERSION("0.0.1");
1157 MODULE_LICENSE("GPL v2");
1158 MODULE_AUTHOR("Michael S. Tsirkin");
1159 MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
1160 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
1161 MODULE_ALIAS("devname:vhost-net");