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9e380825ab
The meth for calculating the # of outstanding buffers gives incorrect results when vq->upend_idx wraps around zero. Fix that. Signed-off-by: Shirley Ma <xma@us.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
882 lines
22 KiB
C
882 lines
22 KiB
C
/* Copyright (C) 2009 Red Hat, Inc.
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* Author: Michael S. Tsirkin <mst@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2.
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*
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* virtio-net server in host kernel.
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*/
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#include <linux/compat.h>
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#include <linux/eventfd.h>
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#include <linux/vhost.h>
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#include <linux/virtio_net.h>
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#include <linux/miscdevice.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/mutex.h>
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#include <linux/workqueue.h>
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#include <linux/rcupdate.h>
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#include <linux/file.h>
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#include <linux/slab.h>
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#include <linux/net.h>
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#include <linux/if_packet.h>
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#include <linux/if_arp.h>
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#include <linux/if_tun.h>
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#include <linux/if_macvlan.h>
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#include <net/sock.h>
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#include "vhost.h"
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static int experimental_zcopytx;
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module_param(experimental_zcopytx, int, 0444);
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MODULE_PARM_DESC(experimental_zcopytx, "Enable Experimental Zero Copy TX");
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/* Max number of bytes transferred before requeueing the job.
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* Using this limit prevents one virtqueue from starving others. */
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#define VHOST_NET_WEIGHT 0x80000
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/* MAX number of TX used buffers for outstanding zerocopy */
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#define VHOST_MAX_PEND 128
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#define VHOST_GOODCOPY_LEN 256
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enum {
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VHOST_NET_VQ_RX = 0,
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VHOST_NET_VQ_TX = 1,
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VHOST_NET_VQ_MAX = 2,
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};
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enum vhost_net_poll_state {
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VHOST_NET_POLL_DISABLED = 0,
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VHOST_NET_POLL_STARTED = 1,
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VHOST_NET_POLL_STOPPED = 2,
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};
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struct vhost_net {
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struct vhost_dev dev;
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struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX];
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struct vhost_poll poll[VHOST_NET_VQ_MAX];
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/* Tells us whether we are polling a socket for TX.
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* We only do this when socket buffer fills up.
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* Protected by tx vq lock. */
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enum vhost_net_poll_state tx_poll_state;
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};
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static bool vhost_sock_zcopy(struct socket *sock)
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{
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return unlikely(experimental_zcopytx) &&
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sock_flag(sock->sk, SOCK_ZEROCOPY);
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}
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/* Pop first len bytes from iovec. Return number of segments used. */
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static int move_iovec_hdr(struct iovec *from, struct iovec *to,
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size_t len, int iov_count)
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{
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int seg = 0;
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size_t size;
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while (len && seg < iov_count) {
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size = min(from->iov_len, len);
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to->iov_base = from->iov_base;
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to->iov_len = size;
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from->iov_len -= size;
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from->iov_base += size;
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len -= size;
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++from;
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++to;
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++seg;
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}
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return seg;
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}
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/* Copy iovec entries for len bytes from iovec. */
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static void copy_iovec_hdr(const struct iovec *from, struct iovec *to,
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size_t len, int iovcount)
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{
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int seg = 0;
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size_t size;
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while (len && seg < iovcount) {
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size = min(from->iov_len, len);
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to->iov_base = from->iov_base;
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to->iov_len = size;
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len -= size;
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++from;
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++to;
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++seg;
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}
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}
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/* Caller must have TX VQ lock */
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static void tx_poll_stop(struct vhost_net *net)
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{
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if (likely(net->tx_poll_state != VHOST_NET_POLL_STARTED))
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return;
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vhost_poll_stop(net->poll + VHOST_NET_VQ_TX);
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net->tx_poll_state = VHOST_NET_POLL_STOPPED;
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}
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/* Caller must have TX VQ lock */
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static void tx_poll_start(struct vhost_net *net, struct socket *sock)
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{
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if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED))
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return;
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vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file);
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net->tx_poll_state = VHOST_NET_POLL_STARTED;
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}
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/* Expects to be always run from workqueue - which acts as
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* read-size critical section for our kind of RCU. */
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static void handle_tx(struct vhost_net *net)
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{
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struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
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unsigned out, in, s;
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int head;
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struct msghdr msg = {
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.msg_name = NULL,
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.msg_namelen = 0,
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.msg_control = NULL,
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.msg_controllen = 0,
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.msg_iov = vq->iov,
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.msg_flags = MSG_DONTWAIT,
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};
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size_t len, total_len = 0;
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int err, wmem;
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size_t hdr_size;
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struct socket *sock;
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struct vhost_ubuf_ref *uninitialized_var(ubufs);
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bool zcopy;
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/* TODO: check that we are running from vhost_worker? */
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sock = rcu_dereference_check(vq->private_data, 1);
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if (!sock)
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return;
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wmem = atomic_read(&sock->sk->sk_wmem_alloc);
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if (wmem >= sock->sk->sk_sndbuf) {
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mutex_lock(&vq->mutex);
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tx_poll_start(net, sock);
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mutex_unlock(&vq->mutex);
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return;
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}
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mutex_lock(&vq->mutex);
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vhost_disable_notify(&net->dev, vq);
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if (wmem < sock->sk->sk_sndbuf / 2)
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tx_poll_stop(net);
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hdr_size = vq->vhost_hlen;
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zcopy = vhost_sock_zcopy(sock);
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for (;;) {
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/* Release DMAs done buffers first */
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if (zcopy)
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vhost_zerocopy_signal_used(vq);
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head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
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ARRAY_SIZE(vq->iov),
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&out, &in,
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NULL, NULL);
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/* On error, stop handling until the next kick. */
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if (unlikely(head < 0))
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break;
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/* Nothing new? Wait for eventfd to tell us they refilled. */
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if (head == vq->num) {
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int num_pends;
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wmem = atomic_read(&sock->sk->sk_wmem_alloc);
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if (wmem >= sock->sk->sk_sndbuf * 3 / 4) {
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tx_poll_start(net, sock);
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set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
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break;
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}
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/* If more outstanding DMAs, queue the work.
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* Handle upend_idx wrap around
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*/
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num_pends = likely(vq->upend_idx >= vq->done_idx) ?
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(vq->upend_idx - vq->done_idx) :
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(vq->upend_idx + UIO_MAXIOV - vq->done_idx);
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if (unlikely(num_pends > VHOST_MAX_PEND)) {
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tx_poll_start(net, sock);
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set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
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break;
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}
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if (unlikely(vhost_enable_notify(&net->dev, vq))) {
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vhost_disable_notify(&net->dev, vq);
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continue;
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}
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break;
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}
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if (in) {
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vq_err(vq, "Unexpected descriptor format for TX: "
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"out %d, int %d\n", out, in);
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break;
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}
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/* Skip header. TODO: support TSO. */
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s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out);
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msg.msg_iovlen = out;
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len = iov_length(vq->iov, out);
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/* Sanity check */
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if (!len) {
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vq_err(vq, "Unexpected header len for TX: "
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"%zd expected %zd\n",
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iov_length(vq->hdr, s), hdr_size);
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break;
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}
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/* use msg_control to pass vhost zerocopy ubuf info to skb */
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if (zcopy) {
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vq->heads[vq->upend_idx].id = head;
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if (len < VHOST_GOODCOPY_LEN) {
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/* copy don't need to wait for DMA done */
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vq->heads[vq->upend_idx].len =
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VHOST_DMA_DONE_LEN;
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msg.msg_control = NULL;
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msg.msg_controllen = 0;
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ubufs = NULL;
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} else {
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struct ubuf_info *ubuf = &vq->ubuf_info[head];
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vq->heads[vq->upend_idx].len = len;
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ubuf->callback = vhost_zerocopy_callback;
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ubuf->arg = vq->ubufs;
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ubuf->desc = vq->upend_idx;
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msg.msg_control = ubuf;
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msg.msg_controllen = sizeof(ubuf);
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ubufs = vq->ubufs;
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kref_get(&ubufs->kref);
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}
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vq->upend_idx = (vq->upend_idx + 1) % UIO_MAXIOV;
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}
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/* TODO: Check specific error and bomb out unless ENOBUFS? */
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err = sock->ops->sendmsg(NULL, sock, &msg, len);
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if (unlikely(err < 0)) {
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if (zcopy) {
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if (ubufs)
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vhost_ubuf_put(ubufs);
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vq->upend_idx = ((unsigned)vq->upend_idx - 1) %
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UIO_MAXIOV;
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}
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vhost_discard_vq_desc(vq, 1);
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tx_poll_start(net, sock);
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break;
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}
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if (err != len)
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pr_debug("Truncated TX packet: "
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" len %d != %zd\n", err, len);
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if (!zcopy)
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vhost_add_used_and_signal(&net->dev, vq, head, 0);
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total_len += len;
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if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
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vhost_poll_queue(&vq->poll);
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break;
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}
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}
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mutex_unlock(&vq->mutex);
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}
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static int peek_head_len(struct sock *sk)
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{
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struct sk_buff *head;
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int len = 0;
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unsigned long flags;
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spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
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head = skb_peek(&sk->sk_receive_queue);
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if (likely(head))
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len = head->len;
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spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
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return len;
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}
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/* This is a multi-buffer version of vhost_get_desc, that works if
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* vq has read descriptors only.
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* @vq - the relevant virtqueue
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* @datalen - data length we'll be reading
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* @iovcount - returned count of io vectors we fill
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* @log - vhost log
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* @log_num - log offset
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* @quota - headcount quota, 1 for big buffer
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* returns number of buffer heads allocated, negative on error
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*/
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static int get_rx_bufs(struct vhost_virtqueue *vq,
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struct vring_used_elem *heads,
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int datalen,
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unsigned *iovcount,
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struct vhost_log *log,
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unsigned *log_num,
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unsigned int quota)
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{
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unsigned int out, in;
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int seg = 0;
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int headcount = 0;
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unsigned d;
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int r, nlogs = 0;
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while (datalen > 0 && headcount < quota) {
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if (unlikely(seg >= UIO_MAXIOV)) {
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r = -ENOBUFS;
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goto err;
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}
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d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
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ARRAY_SIZE(vq->iov) - seg, &out,
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&in, log, log_num);
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if (d == vq->num) {
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r = 0;
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goto err;
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}
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if (unlikely(out || in <= 0)) {
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vq_err(vq, "unexpected descriptor format for RX: "
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"out %d, in %d\n", out, in);
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r = -EINVAL;
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goto err;
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}
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if (unlikely(log)) {
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nlogs += *log_num;
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log += *log_num;
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}
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heads[headcount].id = d;
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heads[headcount].len = iov_length(vq->iov + seg, in);
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datalen -= heads[headcount].len;
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++headcount;
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seg += in;
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}
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heads[headcount - 1].len += datalen;
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*iovcount = seg;
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if (unlikely(log))
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*log_num = nlogs;
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return headcount;
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err:
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vhost_discard_vq_desc(vq, headcount);
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return r;
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}
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/* Expects to be always run from workqueue - which acts as
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* read-size critical section for our kind of RCU. */
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static void handle_rx(struct vhost_net *net)
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{
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struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
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unsigned uninitialized_var(in), log;
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struct vhost_log *vq_log;
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struct msghdr msg = {
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.msg_name = NULL,
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.msg_namelen = 0,
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.msg_control = NULL, /* FIXME: get and handle RX aux data. */
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.msg_controllen = 0,
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.msg_iov = vq->iov,
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.msg_flags = MSG_DONTWAIT,
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};
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struct virtio_net_hdr_mrg_rxbuf hdr = {
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.hdr.flags = 0,
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.hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
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};
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size_t total_len = 0;
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int err, headcount, mergeable;
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size_t vhost_hlen, sock_hlen;
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size_t vhost_len, sock_len;
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/* TODO: check that we are running from vhost_worker? */
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struct socket *sock = rcu_dereference_check(vq->private_data, 1);
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if (!sock)
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return;
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mutex_lock(&vq->mutex);
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vhost_disable_notify(&net->dev, vq);
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vhost_hlen = vq->vhost_hlen;
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sock_hlen = vq->sock_hlen;
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vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
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vq->log : NULL;
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mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);
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while ((sock_len = peek_head_len(sock->sk))) {
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sock_len += sock_hlen;
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vhost_len = sock_len + vhost_hlen;
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headcount = get_rx_bufs(vq, vq->heads, vhost_len,
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&in, vq_log, &log,
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likely(mergeable) ? UIO_MAXIOV : 1);
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/* On error, stop handling until the next kick. */
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if (unlikely(headcount < 0))
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break;
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/* OK, now we need to know about added descriptors. */
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if (!headcount) {
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if (unlikely(vhost_enable_notify(&net->dev, vq))) {
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/* They have slipped one in as we were
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* doing that: check again. */
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vhost_disable_notify(&net->dev, vq);
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continue;
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}
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/* Nothing new? Wait for eventfd to tell us
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* they refilled. */
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break;
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}
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/* We don't need to be notified again. */
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if (unlikely((vhost_hlen)))
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/* Skip header. TODO: support TSO. */
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move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in);
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else
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/* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
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* needed because recvmsg can modify msg_iov. */
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copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in);
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msg.msg_iovlen = in;
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err = sock->ops->recvmsg(NULL, sock, &msg,
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sock_len, MSG_DONTWAIT | MSG_TRUNC);
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/* Userspace might have consumed the packet meanwhile:
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* it's not supposed to do this usually, but might be hard
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* to prevent. Discard data we got (if any) and keep going. */
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if (unlikely(err != sock_len)) {
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pr_debug("Discarded rx packet: "
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" len %d, expected %zd\n", err, sock_len);
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vhost_discard_vq_desc(vq, headcount);
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continue;
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}
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if (unlikely(vhost_hlen) &&
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memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0,
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vhost_hlen)) {
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vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
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vq->iov->iov_base);
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break;
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}
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/* TODO: Should check and handle checksum. */
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if (likely(mergeable) &&
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memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount,
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offsetof(typeof(hdr), num_buffers),
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sizeof hdr.num_buffers)) {
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vq_err(vq, "Failed num_buffers write");
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vhost_discard_vq_desc(vq, headcount);
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break;
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}
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vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
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headcount);
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if (unlikely(vq_log))
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vhost_log_write(vq, vq_log, log, vhost_len);
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total_len += vhost_len;
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if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
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vhost_poll_queue(&vq->poll);
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break;
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}
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}
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mutex_unlock(&vq->mutex);
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}
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static void handle_tx_kick(struct vhost_work *work)
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{
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struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
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poll.work);
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struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
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handle_tx(net);
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}
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static void handle_rx_kick(struct vhost_work *work)
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{
|
|
struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
|
|
poll.work);
|
|
struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
|
|
|
|
handle_rx(net);
|
|
}
|
|
|
|
static void handle_tx_net(struct vhost_work *work)
|
|
{
|
|
struct vhost_net *net = container_of(work, struct vhost_net,
|
|
poll[VHOST_NET_VQ_TX].work);
|
|
handle_tx(net);
|
|
}
|
|
|
|
static void handle_rx_net(struct vhost_work *work)
|
|
{
|
|
struct vhost_net *net = container_of(work, struct vhost_net,
|
|
poll[VHOST_NET_VQ_RX].work);
|
|
handle_rx(net);
|
|
}
|
|
|
|
static int vhost_net_open(struct inode *inode, struct file *f)
|
|
{
|
|
struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
|
|
struct vhost_dev *dev;
|
|
int r;
|
|
|
|
if (!n)
|
|
return -ENOMEM;
|
|
|
|
dev = &n->dev;
|
|
n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
|
|
n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
|
|
r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
|
|
if (r < 0) {
|
|
kfree(n);
|
|
return r;
|
|
}
|
|
|
|
vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
|
|
vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
|
|
n->tx_poll_state = VHOST_NET_POLL_DISABLED;
|
|
|
|
f->private_data = n;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void vhost_net_disable_vq(struct vhost_net *n,
|
|
struct vhost_virtqueue *vq)
|
|
{
|
|
if (!vq->private_data)
|
|
return;
|
|
if (vq == n->vqs + VHOST_NET_VQ_TX) {
|
|
tx_poll_stop(n);
|
|
n->tx_poll_state = VHOST_NET_POLL_DISABLED;
|
|
} else
|
|
vhost_poll_stop(n->poll + VHOST_NET_VQ_RX);
|
|
}
|
|
|
|
static void vhost_net_enable_vq(struct vhost_net *n,
|
|
struct vhost_virtqueue *vq)
|
|
{
|
|
struct socket *sock;
|
|
|
|
sock = rcu_dereference_protected(vq->private_data,
|
|
lockdep_is_held(&vq->mutex));
|
|
if (!sock)
|
|
return;
|
|
if (vq == n->vqs + VHOST_NET_VQ_TX) {
|
|
n->tx_poll_state = VHOST_NET_POLL_STOPPED;
|
|
tx_poll_start(n, sock);
|
|
} else
|
|
vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file);
|
|
}
|
|
|
|
static struct socket *vhost_net_stop_vq(struct vhost_net *n,
|
|
struct vhost_virtqueue *vq)
|
|
{
|
|
struct socket *sock;
|
|
|
|
mutex_lock(&vq->mutex);
|
|
sock = rcu_dereference_protected(vq->private_data,
|
|
lockdep_is_held(&vq->mutex));
|
|
vhost_net_disable_vq(n, vq);
|
|
rcu_assign_pointer(vq->private_data, NULL);
|
|
mutex_unlock(&vq->mutex);
|
|
return sock;
|
|
}
|
|
|
|
static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
|
|
struct socket **rx_sock)
|
|
{
|
|
*tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX);
|
|
*rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX);
|
|
}
|
|
|
|
static void vhost_net_flush_vq(struct vhost_net *n, int index)
|
|
{
|
|
vhost_poll_flush(n->poll + index);
|
|
vhost_poll_flush(&n->dev.vqs[index].poll);
|
|
}
|
|
|
|
static void vhost_net_flush(struct vhost_net *n)
|
|
{
|
|
vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
|
|
vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
|
|
}
|
|
|
|
static int vhost_net_release(struct inode *inode, struct file *f)
|
|
{
|
|
struct vhost_net *n = f->private_data;
|
|
struct socket *tx_sock;
|
|
struct socket *rx_sock;
|
|
|
|
vhost_net_stop(n, &tx_sock, &rx_sock);
|
|
vhost_net_flush(n);
|
|
vhost_dev_cleanup(&n->dev);
|
|
if (tx_sock)
|
|
fput(tx_sock->file);
|
|
if (rx_sock)
|
|
fput(rx_sock->file);
|
|
/* We do an extra flush before freeing memory,
|
|
* since jobs can re-queue themselves. */
|
|
vhost_net_flush(n);
|
|
kfree(n);
|
|
return 0;
|
|
}
|
|
|
|
static struct socket *get_raw_socket(int fd)
|
|
{
|
|
struct {
|
|
struct sockaddr_ll sa;
|
|
char buf[MAX_ADDR_LEN];
|
|
} uaddr;
|
|
int uaddr_len = sizeof uaddr, r;
|
|
struct socket *sock = sockfd_lookup(fd, &r);
|
|
|
|
if (!sock)
|
|
return ERR_PTR(-ENOTSOCK);
|
|
|
|
/* Parameter checking */
|
|
if (sock->sk->sk_type != SOCK_RAW) {
|
|
r = -ESOCKTNOSUPPORT;
|
|
goto err;
|
|
}
|
|
|
|
r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
|
|
&uaddr_len, 0);
|
|
if (r)
|
|
goto err;
|
|
|
|
if (uaddr.sa.sll_family != AF_PACKET) {
|
|
r = -EPFNOSUPPORT;
|
|
goto err;
|
|
}
|
|
return sock;
|
|
err:
|
|
fput(sock->file);
|
|
return ERR_PTR(r);
|
|
}
|
|
|
|
static struct socket *get_tap_socket(int fd)
|
|
{
|
|
struct file *file = fget(fd);
|
|
struct socket *sock;
|
|
|
|
if (!file)
|
|
return ERR_PTR(-EBADF);
|
|
sock = tun_get_socket(file);
|
|
if (!IS_ERR(sock))
|
|
return sock;
|
|
sock = macvtap_get_socket(file);
|
|
if (IS_ERR(sock))
|
|
fput(file);
|
|
return sock;
|
|
}
|
|
|
|
static struct socket *get_socket(int fd)
|
|
{
|
|
struct socket *sock;
|
|
|
|
/* special case to disable backend */
|
|
if (fd == -1)
|
|
return NULL;
|
|
sock = get_raw_socket(fd);
|
|
if (!IS_ERR(sock))
|
|
return sock;
|
|
sock = get_tap_socket(fd);
|
|
if (!IS_ERR(sock))
|
|
return sock;
|
|
return ERR_PTR(-ENOTSOCK);
|
|
}
|
|
|
|
static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
|
|
{
|
|
struct socket *sock, *oldsock;
|
|
struct vhost_virtqueue *vq;
|
|
struct vhost_ubuf_ref *ubufs, *oldubufs = NULL;
|
|
int r;
|
|
|
|
mutex_lock(&n->dev.mutex);
|
|
r = vhost_dev_check_owner(&n->dev);
|
|
if (r)
|
|
goto err;
|
|
|
|
if (index >= VHOST_NET_VQ_MAX) {
|
|
r = -ENOBUFS;
|
|
goto err;
|
|
}
|
|
vq = n->vqs + index;
|
|
mutex_lock(&vq->mutex);
|
|
|
|
/* Verify that ring has been setup correctly. */
|
|
if (!vhost_vq_access_ok(vq)) {
|
|
r = -EFAULT;
|
|
goto err_vq;
|
|
}
|
|
sock = get_socket(fd);
|
|
if (IS_ERR(sock)) {
|
|
r = PTR_ERR(sock);
|
|
goto err_vq;
|
|
}
|
|
|
|
/* start polling new socket */
|
|
oldsock = rcu_dereference_protected(vq->private_data,
|
|
lockdep_is_held(&vq->mutex));
|
|
if (sock != oldsock) {
|
|
ubufs = vhost_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock));
|
|
if (IS_ERR(ubufs)) {
|
|
r = PTR_ERR(ubufs);
|
|
goto err_ubufs;
|
|
}
|
|
oldubufs = vq->ubufs;
|
|
vq->ubufs = ubufs;
|
|
vhost_net_disable_vq(n, vq);
|
|
rcu_assign_pointer(vq->private_data, sock);
|
|
vhost_net_enable_vq(n, vq);
|
|
|
|
r = vhost_init_used(vq);
|
|
if (r)
|
|
goto err_vq;
|
|
}
|
|
|
|
mutex_unlock(&vq->mutex);
|
|
|
|
if (oldubufs) {
|
|
vhost_ubuf_put_and_wait(oldubufs);
|
|
mutex_lock(&vq->mutex);
|
|
vhost_zerocopy_signal_used(vq);
|
|
mutex_unlock(&vq->mutex);
|
|
}
|
|
|
|
if (oldsock) {
|
|
vhost_net_flush_vq(n, index);
|
|
fput(oldsock->file);
|
|
}
|
|
|
|
mutex_unlock(&n->dev.mutex);
|
|
return 0;
|
|
|
|
err_ubufs:
|
|
fput(sock->file);
|
|
err_vq:
|
|
mutex_unlock(&vq->mutex);
|
|
err:
|
|
mutex_unlock(&n->dev.mutex);
|
|
return r;
|
|
}
|
|
|
|
static long vhost_net_reset_owner(struct vhost_net *n)
|
|
{
|
|
struct socket *tx_sock = NULL;
|
|
struct socket *rx_sock = NULL;
|
|
long err;
|
|
|
|
mutex_lock(&n->dev.mutex);
|
|
err = vhost_dev_check_owner(&n->dev);
|
|
if (err)
|
|
goto done;
|
|
vhost_net_stop(n, &tx_sock, &rx_sock);
|
|
vhost_net_flush(n);
|
|
err = vhost_dev_reset_owner(&n->dev);
|
|
done:
|
|
mutex_unlock(&n->dev.mutex);
|
|
if (tx_sock)
|
|
fput(tx_sock->file);
|
|
if (rx_sock)
|
|
fput(rx_sock->file);
|
|
return err;
|
|
}
|
|
|
|
static int vhost_net_set_features(struct vhost_net *n, u64 features)
|
|
{
|
|
size_t vhost_hlen, sock_hlen, hdr_len;
|
|
int i;
|
|
|
|
hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
|
|
sizeof(struct virtio_net_hdr_mrg_rxbuf) :
|
|
sizeof(struct virtio_net_hdr);
|
|
if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
|
|
/* vhost provides vnet_hdr */
|
|
vhost_hlen = hdr_len;
|
|
sock_hlen = 0;
|
|
} else {
|
|
/* socket provides vnet_hdr */
|
|
vhost_hlen = 0;
|
|
sock_hlen = hdr_len;
|
|
}
|
|
mutex_lock(&n->dev.mutex);
|
|
if ((features & (1 << VHOST_F_LOG_ALL)) &&
|
|
!vhost_log_access_ok(&n->dev)) {
|
|
mutex_unlock(&n->dev.mutex);
|
|
return -EFAULT;
|
|
}
|
|
n->dev.acked_features = features;
|
|
smp_wmb();
|
|
for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
|
|
mutex_lock(&n->vqs[i].mutex);
|
|
n->vqs[i].vhost_hlen = vhost_hlen;
|
|
n->vqs[i].sock_hlen = sock_hlen;
|
|
mutex_unlock(&n->vqs[i].mutex);
|
|
}
|
|
vhost_net_flush(n);
|
|
mutex_unlock(&n->dev.mutex);
|
|
return 0;
|
|
}
|
|
|
|
static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
|
|
unsigned long arg)
|
|
{
|
|
struct vhost_net *n = f->private_data;
|
|
void __user *argp = (void __user *)arg;
|
|
u64 __user *featurep = argp;
|
|
struct vhost_vring_file backend;
|
|
u64 features;
|
|
int r;
|
|
|
|
switch (ioctl) {
|
|
case VHOST_NET_SET_BACKEND:
|
|
if (copy_from_user(&backend, argp, sizeof backend))
|
|
return -EFAULT;
|
|
return vhost_net_set_backend(n, backend.index, backend.fd);
|
|
case VHOST_GET_FEATURES:
|
|
features = VHOST_FEATURES;
|
|
if (copy_to_user(featurep, &features, sizeof features))
|
|
return -EFAULT;
|
|
return 0;
|
|
case VHOST_SET_FEATURES:
|
|
if (copy_from_user(&features, featurep, sizeof features))
|
|
return -EFAULT;
|
|
if (features & ~VHOST_FEATURES)
|
|
return -EOPNOTSUPP;
|
|
return vhost_net_set_features(n, features);
|
|
case VHOST_RESET_OWNER:
|
|
return vhost_net_reset_owner(n);
|
|
default:
|
|
mutex_lock(&n->dev.mutex);
|
|
r = vhost_dev_ioctl(&n->dev, ioctl, arg);
|
|
vhost_net_flush(n);
|
|
mutex_unlock(&n->dev.mutex);
|
|
return r;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
|
|
unsigned long arg)
|
|
{
|
|
return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
|
|
}
|
|
#endif
|
|
|
|
static const struct file_operations vhost_net_fops = {
|
|
.owner = THIS_MODULE,
|
|
.release = vhost_net_release,
|
|
.unlocked_ioctl = vhost_net_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = vhost_net_compat_ioctl,
|
|
#endif
|
|
.open = vhost_net_open,
|
|
.llseek = noop_llseek,
|
|
};
|
|
|
|
static struct miscdevice vhost_net_misc = {
|
|
MISC_DYNAMIC_MINOR,
|
|
"vhost-net",
|
|
&vhost_net_fops,
|
|
};
|
|
|
|
static int vhost_net_init(void)
|
|
{
|
|
if (experimental_zcopytx)
|
|
vhost_enable_zcopy(VHOST_NET_VQ_TX);
|
|
return misc_register(&vhost_net_misc);
|
|
}
|
|
module_init(vhost_net_init);
|
|
|
|
static void vhost_net_exit(void)
|
|
{
|
|
misc_deregister(&vhost_net_misc);
|
|
}
|
|
module_exit(vhost_net_exit);
|
|
|
|
MODULE_VERSION("0.0.1");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_AUTHOR("Michael S. Tsirkin");
|
|
MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
|