Subject: Re: [PATCH v3 3/4] VSOCK: Introduce vhost-vsock.ko

From: Alex Bennée <[email-masked]>
Date: Fri, 11 Dec 2015 13:45:29 +0000

Stefan Hajnoczi <[email-masked]> writes:

> From: Asias He <[email-masked]>
>
> VM sockets vhost transport implementation. This module runs in host
> kernel.

As per previous checkpatch comments.

>
> Signed-off-by: Asias He <[email-masked]>
> Signed-off-by: Stefan Hajnoczi <[email-masked]>
> ---
> v3:
>  * Remove unneeded variable used to store return value
>    (Fengguang Wu <[email-masked]> and Julia Lawall
>    <[email-masked]>)
> v2:
>  * Add missing total_tx_buf decrement
>  * Support flexible rx/tx descriptor layout
>  * Refuse to assign reserved CIDs
>  * Refuse guest CID if already in use
>  * Only accept correctly addressed packets
> ---
>  drivers/vhost/vsock.c | 628 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/vhost/vsock.h |   4 +
>  2 files changed, 632 insertions(+)
>  create mode 100644 drivers/vhost/vsock.c
>  create mode 100644 drivers/vhost/vsock.h
>
> diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
> new file mode 100644
> index 0000000..3c0034a
> --- /dev/null
> +++ b/drivers/vhost/vsock.c
> @@ -0,0 +1,628 @@
> +/*
> + * vhost transport for vsock
> + *
> + * Copyright (C) 2013-2015 Red Hat, Inc.
> + * Author: Asias He <[email-masked]>
> + *         Stefan Hajnoczi <[email-masked]>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.
> + */
> +#include <linux/miscdevice.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <net/sock.h>
> +#include <linux/virtio_vsock.h>
> +#include <linux/vhost.h>
> +
> +#include <net/af_vsock.h>
> +#include "vhost.h"
> +#include "vsock.h"
> +
> +#define VHOST_VSOCK_DEFAULT_HOST_CID	2
> +
> +static int vhost_transport_socket_init(struct vsock_sock *vsk,
> +				       struct vsock_sock *psk);
> +
> +enum {
> +	VHOST_VSOCK_FEATURES = VHOST_FEATURES,
> +};
> +
> +/* Used to track all the vhost_vsock instances on the system. */
> +static LIST_HEAD(vhost_vsock_list);
> +static DEFINE_MUTEX(vhost_vsock_mutex);
> +
> +struct vhost_vsock_virtqueue {
> +	struct vhost_virtqueue vq;
> +};
> +
> +struct vhost_vsock {
> +	/* Vhost device */
> +	struct vhost_dev dev;
> +	/* Vhost vsock virtqueue*/
> +	struct vhost_vsock_virtqueue vqs[VSOCK_VQ_MAX];
> +	/* Link to global vhost_vsock_list*/
> +	struct list_head list;
> +	/* Head for pkt from host to guest */
> +	struct list_head send_pkt_list;
> +	/* Work item to send pkt */
> +	struct vhost_work send_pkt_work;
> +	/* Wait queue for send pkt */
> +	wait_queue_head_t queue_wait;
> +	/* Used for global tx buf limitation */
> +	u32 total_tx_buf;
> +	/* Guest contex id this vhost_vsock instance handles */
> +	u32 guest_cid;
> +};

As with 2/4 there is a fair bit of redundancy in the comments but I
don't see any obvious grouping here that could streamline it.

> +
> +static u32 vhost_transport_get_local_cid(void)
> +{
> +	return VHOST_VSOCK_DEFAULT_HOST_CID;
> +}
> +
> +static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
> +{
> +	struct vhost_vsock *vsock;
> +
> +	mutex_lock(&vhost_vsock_mutex);
> +	list_for_each_entry(vsock, &vhost_vsock_list, list) {
> +		if (vsock->guest_cid == guest_cid) {
> +			mutex_unlock(&vhost_vsock_mutex);
> +			return vsock;
> +		}
> +	}
> +	mutex_unlock(&vhost_vsock_mutex);
> +
> +	return NULL;
> +}
> +
> +static void
> +vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
> +			    struct vhost_virtqueue *vq)
> +{
> +	bool added = false;
> +
> +	mutex_lock(&vq->mutex);
> +	vhost_disable_notify(&vsock->dev, vq);
> +	for (;;) {
> +		struct virtio_vsock_pkt *pkt;
> +		struct iov_iter iov_iter;
> +		unsigned out, in;
> +		struct sock *sk;
> +		size_t nbytes;
> +		size_t len;
> +		int head;
> +
> +		if (list_empty(&vsock->send_pkt_list)) {
> +			vhost_enable_notify(&vsock->dev, vq);
> +			break;
> +		}
> +
> +		head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
> +					 &out, &in, NULL, NULL);
> +		pr_debug("%s: head = %d\n", __func__, head);
> +		if (head < 0)
> +			break;
> +
> +		if (head == vq->num) {
> +			if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
> +				vhost_disable_notify(&vsock->dev, vq);
> +				continue;

Why are we doing this? If we enable something we then disable it? A
comment as to what is going on here would be useful.

> +			}
> +			break;
> +		}
> +
> +		pkt = list_first_entry(&vsock->send_pkt_list,
> +				       struct virtio_vsock_pkt, list);
> +		list_del_init(&pkt->list);
> +
> +		if (out) {
> +			virtio_transport_free_pkt(pkt);
> +			vq_err(vq, "Expected 0 output buffers, got %u\n", out);
> +			break;
> +		}
> +
> +		len = iov_length(&vq->iov[out], in);
> +		iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len);
> +
> +		nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
> +		if (nbytes != sizeof(pkt->hdr)) {
> +			virtio_transport_free_pkt(pkt);
> +			vq_err(vq, "Faulted on copying pkt hdr\n");
> +			break;
> +		}
> +
> +		nbytes = copy_to_iter(pkt->buf, pkt->len, &iov_iter);
> +		if (nbytes != pkt->len) {
> +			virtio_transport_free_pkt(pkt);
> +			vq_err(vq, "Faulted on copying pkt buf\n");
> +			break;
> +		}
> +
> +		vhost_add_used(vq, head, pkt->len); /* TODO should this
> be sizeof(pkt->hdr) + pkt->len? */

TODO needs sorting our or removing.

> +		added = true;
> +
> +		virtio_transport_dec_tx_pkt(pkt);
> +		vsock->total_tx_buf -= pkt->len;
> +
> +		sk = sk_vsock(pkt->trans->vsk);
> +		/* Release refcnt taken in vhost_transport_send_pkt */
> +		sock_put(sk);
> +
> +		virtio_transport_free_pkt(pkt);
> +	}
> +	if (added)
> +		vhost_signal(&vsock->dev, vq);
> +	mutex_unlock(&vq->mutex);
> +
> +	if (added)
> +		wake_up(&vsock->queue_wait);
> +}
> +
> +static void vhost_transport_send_pkt_work(struct vhost_work *work)
> +{
> +	struct vhost_virtqueue *vq;
> +	struct vhost_vsock *vsock;
> +
> +	vsock = container_of(work, struct vhost_vsock, send_pkt_work);
> +	vq = &vsock->vqs[VSOCK_VQ_RX].vq;
> +
> +	vhost_transport_do_send_pkt(vsock, vq);
> +}
> +
> +static int
> +vhost_transport_send_pkt(struct vsock_sock *vsk,
> +			 struct virtio_vsock_pkt_info *info)
> +{
> +	u32 src_cid, src_port, dst_cid, dst_port;
> +	struct virtio_transport *trans;
> +	struct virtio_vsock_pkt *pkt;
> +	struct vhost_virtqueue *vq;
> +	struct vhost_vsock *vsock;
> +	u32 pkt_len = info->pkt_len;
> +	DEFINE_WAIT(wait);
> +
> +	src_cid = vhost_transport_get_local_cid();
> +	src_port = vsk->local_addr.svm_port;
> +	if (!info->remote_cid) {
> +		dst_cid	= vsk->remote_addr.svm_cid;
> +		dst_port = vsk->remote_addr.svm_port;
> +	} else {
> +		dst_cid = info->remote_cid;
> +		dst_port = info->remote_port;
> +	}
> +
> +	/* Find the vhost_vsock according to guest context id  */
> +	vsock = vhost_vsock_get(dst_cid);
> +	if (!vsock)
> +		return -ENODEV;
> +
> +	trans = vsk->trans;
> +	vq = &vsock->vqs[VSOCK_VQ_RX].vq;
> +
> +	/* we can send less than pkt_len bytes */
> +	if (pkt_len > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE)
> +		pkt_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
> +
> +	/* virtio_transport_get_credit might return less than pkt_len credit */
> +	pkt_len = virtio_transport_get_credit(trans, pkt_len);
> +
> +	/* Do not send zero length OP_RW pkt*/
> +	if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
> +		return pkt_len;
> +
> +	/* Respect global tx buf limitation */
> +	mutex_lock(&vq->mutex);
> +	while (pkt_len + vsock->total_tx_buf >
> VIRTIO_VSOCK_MAX_TX_BUF_SIZE) {

I'm curious about the relationship between
VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE above and VIRTIO_VSOCK_MAX_TX_BUF_SIZE
just here. Why do we need to limit pkt_len to the smaller when really
all that matters is pkt_len + vsock->total_tx_buf >
VIRTIO_VSOCK_MAX_TX_BUF_SIZE?

> +		prepare_to_wait_exclusive(&vsock->queue_wait, &wait,
> +					  TASK_UNINTERRUPTIBLE);
> +		mutex_unlock(&vq->mutex);
> +		schedule();
> +		mutex_lock(&vq->mutex);
> +		finish_wait(&vsock->queue_wait, &wait);
> +	}
> +	vsock->total_tx_buf += pkt_len;
> +	mutex_unlock(&vq->mutex);
> +
> +	pkt = virtio_transport_alloc_pkt(vsk, info, pkt_len,
> +					 src_cid, src_port,
> +					 dst_cid, dst_port);
> +	if (!pkt) {
> +		mutex_lock(&vq->mutex);
> +		vsock->total_tx_buf -= pkt_len;
> +		mutex_unlock(&vq->mutex);
> +		virtio_transport_put_credit(trans, pkt_len);
> +		return -ENOMEM;
> +	}
> +
> +	pr_debug("%s:info->pkt_len= %d\n", __func__, pkt_len);
> +	/* Released in vhost_transport_do_send_pkt */
> +	sock_hold(&trans->vsk->sk);
> +	virtio_transport_inc_tx_pkt(pkt);
> +
> +	/* Queue it up in vhost work */
> +	mutex_lock(&vq->mutex);
> +	list_add_tail(&pkt->list, &vsock->send_pkt_list);
> +	vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
> +	mutex_unlock(&vq->mutex);
> +
> +	return pkt_len;
> +}
> +
> +static struct virtio_transport_pkt_ops vhost_ops = {
> +	.send_pkt = vhost_transport_send_pkt,
> +};
> +
> +static struct virtio_vsock_pkt *
> +vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
> +		      unsigned int out, unsigned int in)
> +{
> +	struct virtio_vsock_pkt *pkt;
> +	struct iov_iter iov_iter;
> +	size_t nbytes;
> +	size_t len;
> +
> +	if (in != 0) {
> +		vq_err(vq, "Expected 0 input buffers, got %u\n", in);
> +		return NULL;
> +	}
> +
> +	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
> +	if (!pkt)
> +		return NULL;
> +
> +	len = iov_length(vq->iov, out);
> +	iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);
> +
> +	nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
> +	if (nbytes != sizeof(pkt->hdr)) {
> +		vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
> +		       sizeof(pkt->hdr), nbytes);
> +		kfree(pkt);
> +		return NULL;
> +	}
> +
> +	if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM)
> +		pkt->len = le32_to_cpu(pkt->hdr.len);
> +
> +	/* No payload */
> +	if (!pkt->len)
> +		return pkt;
> +
> +	/* The pkt is too big */
> +	if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
> +		kfree(pkt);
> +		return NULL;
> +	}
> +
> +	pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
> +	if (!pkt->buf) {
> +		kfree(pkt);
> +		return NULL;
> +	}
> +
> +	nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
> +	if (nbytes != pkt->len) {
> +		vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
> +		       pkt->len, nbytes);
> +		virtio_transport_free_pkt(pkt);
> +		return NULL;
> +	}
> +
> +	return pkt;
> +}
> +
> +static void vhost_vsock_handle_ctl_kick(struct vhost_work *work)
> +{
> +	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
> +						  poll.work);
> +	struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
> +						 dev);
> +
> +	pr_debug("%s vq=%p, vsock=%p\n", __func__, vq, vsock);
> +}

This doesn't handle anything, it just prints debug stuff. Should this be
a NOP function?

> +
> +static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
> +{
> +	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
> +						  poll.work);
> +	struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
> +						 dev);
> +	struct virtio_vsock_pkt *pkt;
> +	int head;
> +	unsigned int out, in;
> +	bool added = false;
> +	u32 len;
> +
> +	mutex_lock(&vq->mutex);
> +	vhost_disable_notify(&vsock->dev, vq);
> +	for (;;) {
> +		head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
> +					 &out, &in, NULL, NULL);
> +		if (head < 0)
> +			break;
> +
> +		if (head == vq->num) {
> +			if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
> +				vhost_disable_notify(&vsock->dev, vq);
> +				continue;

Same question about the enable/disable dance as above.

> +			}
> +			break;
> +		}
> +
> +		pkt = vhost_vsock_alloc_pkt(vq, out, in);
> +		if (!pkt) {
> +			vq_err(vq, "Faulted on pkt\n");
> +			continue;
> +		}
> +
> +		len = pkt->len;
> +
> +		/* Only accept correctly addressed packets */
> +		if (le32_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid &&
> +		    le32_to_cpu(pkt->hdr.dst_cid) == vhost_transport_get_local_cid())
> +			virtio_transport_recv_pkt(pkt);
> +		else
> +			virtio_transport_free_pkt(pkt);
> +
> +		vhost_add_used(vq, head, len);
> +		added = true;
> +	}
> +	if (added)
> +		vhost_signal(&vsock->dev, vq);
> +	mutex_unlock(&vq->mutex);
> +}
> +
> +static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
> +{
> +	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
> +						poll.work);
> +	struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
> +						 dev);
> +
> +	vhost_transport_do_send_pkt(vsock, vq);
> +}
> +
> +static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
> +{
> +	struct vhost_virtqueue **vqs;
> +	struct vhost_vsock *vsock;
> +	int ret;
> +
> +	vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
> +	if (!vsock)
> +		return -ENOMEM;
> +
> +	pr_debug("%s:vsock=%p\n", __func__, vsock);
> +
> +	vqs = kmalloc(VSOCK_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
> +	if (!vqs) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	vqs[VSOCK_VQ_CTRL] = &vsock->vqs[VSOCK_VQ_CTRL].vq;
> +	vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX].vq;
> +	vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX].vq;
> +	vsock->vqs[VSOCK_VQ_CTRL].vq.handle_kick = vhost_vsock_handle_ctl_kick;
> +	vsock->vqs[VSOCK_VQ_TX].vq.handle_kick = vhost_vsock_handle_tx_kick;
> +	vsock->vqs[VSOCK_VQ_RX].vq.handle_kick = vhost_vsock_handle_rx_kick;
> +
> +	vhost_dev_init(&vsock->dev, vqs, VSOCK_VQ_MAX);
> +
> +	file->private_data = vsock;
> +	init_waitqueue_head(&vsock->queue_wait);
> +	INIT_LIST_HEAD(&vsock->send_pkt_list);
> +	vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
> +
> +	mutex_lock(&vhost_vsock_mutex);
> +	list_add_tail(&vsock->list, &vhost_vsock_list);
> +	mutex_unlock(&vhost_vsock_mutex);
> +	return 0;
> +
> +out:
> +	kfree(vsock);
> +	return ret;
> +}
> +
> +static void vhost_vsock_flush(struct vhost_vsock *vsock)
> +{
> +	int i;
> +
> +	for (i = 0; i < VSOCK_VQ_MAX; i++)
> +		vhost_poll_flush(&vsock->vqs[i].vq.poll);
> +	vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
> +}
> +
> +static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
> +{
> +	struct vhost_vsock *vsock = file->private_data;
> +
> +	mutex_lock(&vhost_vsock_mutex);
> +	list_del(&vsock->list);
> +	mutex_unlock(&vhost_vsock_mutex);
> +
> +	vhost_dev_stop(&vsock->dev);
> +	vhost_vsock_flush(vsock);
> +	vhost_dev_cleanup(&vsock->dev, false);
> +	kfree(vsock->dev.vqs);
> +	kfree(vsock);
> +	return 0;
> +}
> +
> +static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u32 guest_cid)
> +{
> +	struct vhost_vsock *other;
> +
> +	/* Refuse reserved CIDs */
> +	if (guest_cid <= VMADDR_CID_HOST) {
> +		return -EINVAL;
> +	}
> +
> +	/* Refuse if CID is already in use */
> +	other = vhost_vsock_get(guest_cid);
> +	if (other && other != vsock) {
> +		return -EADDRINUSE;
> +	}
> +
> +	mutex_lock(&vhost_vsock_mutex);
> +	vsock->guest_cid = guest_cid;
> +	pr_debug("%s:guest_cid=%d\n", __func__, guest_cid);
> +	mutex_unlock(&vhost_vsock_mutex);
> +
> +	return 0;
> +}
> +
> +static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
> +{
> +	struct vhost_virtqueue *vq;
> +	int i;
> +
> +	if (features & ~VHOST_VSOCK_FEATURES)
> +		return -EOPNOTSUPP;
> +
> +	mutex_lock(&vsock->dev.mutex);
> +	if ((features & (1 << VHOST_F_LOG_ALL)) &&
> +	    !vhost_log_access_ok(&vsock->dev)) {
> +		mutex_unlock(&vsock->dev.mutex);
> +		return -EFAULT;
> +	}
> +
> +	for (i = 0; i < VSOCK_VQ_MAX; i++) {
> +		vq = &vsock->vqs[i].vq;
> +		mutex_lock(&vq->mutex);
> +		vq->acked_features = features;

Is this a user supplied flag? Should it be masked to valid values?

> +		mutex_unlock(&vq->mutex);
> +	}
> +	mutex_unlock(&vsock->dev.mutex);
> +	return 0;
> +}
> +
> +static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
> +				  unsigned long arg)
> +{
> +	struct vhost_vsock *vsock = f->private_data;
> +	void __user *argp = (void __user *)arg;
> +	u64 __user *featurep = argp;
> +	u32 __user *cidp = argp;
> +	u32 guest_cid;
> +	u64 features;
> +	int r;
> +
> +	switch (ioctl) {
> +	case VHOST_VSOCK_SET_GUEST_CID:
> +		if (get_user(guest_cid, cidp))
> +			return -EFAULT;
> +		return vhost_vsock_set_cid(vsock, guest_cid);
> +	case VHOST_GET_FEATURES:
> +		features = VHOST_VSOCK_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;
> +		return vhost_vsock_set_features(vsock, features);
> +	default:
> +		mutex_lock(&vsock->dev.mutex);
> +		r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
> +		if (r == -ENOIOCTLCMD)
> +			r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
> +		else
> +			vhost_vsock_flush(vsock);
> +		mutex_unlock(&vsock->dev.mutex);
> +		return r;
> +	}
> +}
> +
> +static const struct file_operations vhost_vsock_fops = {
> +	.owner          = THIS_MODULE,
> +	.open           = vhost_vsock_dev_open,
> +	.release        = vhost_vsock_dev_release,
> +	.llseek		= noop_llseek,
> +	.unlocked_ioctl = vhost_vsock_dev_ioctl,
> +};
> +
> +static struct miscdevice vhost_vsock_misc = {
> +	.minor = MISC_DYNAMIC_MINOR,
> +	.name = "vhost-vsock",
> +	.fops = &vhost_vsock_fops,
> +};
> +
> +static int
> +vhost_transport_socket_init(struct vsock_sock *vsk, struct vsock_sock *psk)
> +{
> +	struct virtio_transport *trans;
> +	int ret;
> +
> +	ret = virtio_transport_do_socket_init(vsk, psk);
> +	if (ret)
> +		return ret;
> +
> +	trans = vsk->trans;
> +	trans->ops = &vhost_ops;
> +
> +	return ret;
> +}
> +
> +static struct vsock_transport vhost_transport = {
> +	.get_local_cid            = vhost_transport_get_local_cid,
> +
> +	.init                     = vhost_transport_socket_init,
> +	.destruct                 = virtio_transport_destruct,
> +	.release                  = virtio_transport_release,
> +	.connect                  = virtio_transport_connect,
> +	.shutdown                 = virtio_transport_shutdown,
> +
> +	.dgram_enqueue            = virtio_transport_dgram_enqueue,
> +	.dgram_dequeue            = virtio_transport_dgram_dequeue,
> +	.dgram_bind               = virtio_transport_dgram_bind,
> +	.dgram_allow              = virtio_transport_dgram_allow,
> +
> +	.stream_enqueue           = virtio_transport_stream_enqueue,
> +	.stream_dequeue           = virtio_transport_stream_dequeue,
> +	.stream_has_data          = virtio_transport_stream_has_data,
> +	.stream_has_space         = virtio_transport_stream_has_space,
> +	.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
> +	.stream_is_active         = virtio_transport_stream_is_active,
> +	.stream_allow             = virtio_transport_stream_allow,
> +
> +	.notify_poll_in           = virtio_transport_notify_poll_in,
> +	.notify_poll_out          = virtio_transport_notify_poll_out,
> +	.notify_recv_init         = virtio_transport_notify_recv_init,
> +	.notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
> +	.notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
> +	.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
> +	.notify_send_init         = virtio_transport_notify_send_init,
> +	.notify_send_pre_block    = virtio_transport_notify_send_pre_block,
> +	.notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
> +	.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
> +
> +	.set_buffer_size          = virtio_transport_set_buffer_size,
> +	.set_min_buffer_size      = virtio_transport_set_min_buffer_size,
> +	.set_max_buffer_size      = virtio_transport_set_max_buffer_size,
> +	.get_buffer_size          = virtio_transport_get_buffer_size,
> +	.get_min_buffer_size      = virtio_transport_get_min_buffer_size,
> +	.get_max_buffer_size      = virtio_transport_get_max_buffer_size,
> +};
> +
> +static int __init vhost_vsock_init(void)
> +{
> +	int ret;
> +
> +	ret = vsock_core_init(&vhost_transport);
> +	if (ret < 0)
> +		return ret;
> +	return misc_register(&vhost_vsock_misc);
> +};
> +
> +static void __exit vhost_vsock_exit(void)
> +{
> +	misc_deregister(&vhost_vsock_misc);
> +	vsock_core_exit();
> +};
> +
> +module_init(vhost_vsock_init);
> +module_exit(vhost_vsock_exit);
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Asias He");
> +MODULE_DESCRIPTION("vhost transport for vsock ");
> diff --git a/drivers/vhost/vsock.h b/drivers/vhost/vsock.h
> new file mode 100644
> index 0000000..0ddb107
> --- /dev/null
> +++ b/drivers/vhost/vsock.h
> @@ -0,0 +1,4 @@
> +#ifndef VHOST_VSOCK_H
> +#define VHOST_VSOCK_H
> +#define VHOST_VSOCK_SET_GUEST_CID _IOW(VHOST_VIRTIO, 0x60, __u32)
> +#endif
> --
> 2.5.0

--
Alex Bennée