VSOCK: Introduce vhost_vsock.ko

VM sockets vhost transport implementation.  This driver runs on the
host.

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 722 insertions, 0 deletions

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
new file mode 100644
index 000000000000..028ca16c2d36
--- /dev/null
+++ b/drivers/vhost/vsock.c
@@ -0,0 +1,722 @@
+/*
+ * vhost transport for vsock
+ *
+ * Copyright (C) 2013-2015 Red Hat, Inc.
+ * Author: Asias He <asias@redhat.com>
+ *         Stefan Hajnoczi <stefanha@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+#include <linux/miscdevice.h>
+#include <linux/atomic.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/vmalloc.h>
+#include <net/sock.h>
+#include <linux/virtio_vsock.h>
+#include <linux/vhost.h>
+
+#include <net/af_vsock.h>
+#include "vhost.h"
+
+#define VHOST_VSOCK_DEFAULT_HOST_CID    2
+
+enum {
+        VHOST_VSOCK_FEATURES = VHOST_FEATURES,
+};
+
+/* Used to track all the vhost_vsock instances on the system. */
+static DEFINE_SPINLOCK(vhost_vsock_lock);
+static LIST_HEAD(vhost_vsock_list);
+
+struct vhost_vsock {
+        struct vhost_dev dev;
+        struct vhost_virtqueue vqs[2];
+
+        /* Link to global vhost_vsock_list, protected by vhost_vsock_lock */
+        struct list_head list;
+
+        struct vhost_work send_pkt_work;
+        spinlock_t send_pkt_list_lock;
+        struct list_head send_pkt_list; /* host->guest pending packets */
+
+        atomic_t queued_replies;
+
+        u32 guest_cid;
+};
+
+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;
+
+        spin_lock_bh(&vhost_vsock_lock);
+        list_for_each_entry(vsock, &vhost_vsock_list, list) {
+                u32 other_cid = vsock->guest_cid;
+
+                /* Skip instances that have no CID yet */
+                if (other_cid == 0)
+                        continue;
+
+                if (other_cid == guest_cid) {
+                        spin_unlock_bh(&vhost_vsock_lock);
+                        return vsock;
+                }
+        }
+        spin_unlock_bh(&vhost_vsock_lock);
+
+        return NULL;
+}
+
+static void
+vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
+                            struct vhost_virtqueue *vq)
+{
+        struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
+        bool added = false;
+        bool restart_tx = false;
+
+        mutex_lock(&vq->mutex);
+
+        if (!vq->private_data)
+                goto out;
+
+        /* Avoid further vmexits, we're already processing the virtqueue */
+        vhost_disable_notify(&vsock->dev, vq);
+
+        for (;;) {
+                struct virtio_vsock_pkt *pkt;
+                struct iov_iter iov_iter;
+                unsigned out, in;
+                size_t nbytes;
+                size_t len;
+                int head;
+
+                spin_lock_bh(&vsock->send_pkt_list_lock);
+                if (list_empty(&vsock->send_pkt_list)) {
+                        spin_unlock_bh(&vsock->send_pkt_list_lock);
+                        vhost_enable_notify(&vsock->dev, vq);
+                        break;
+                }
+
+                pkt = list_first_entry(&vsock->send_pkt_list,
+                                       struct virtio_vsock_pkt, list);
+                list_del_init(&pkt->list);
+                spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+                head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
+                                         &out, &in, NULL, NULL);
+                if (head < 0) {
+                        spin_lock_bh(&vsock->send_pkt_list_lock);
+                        list_add(&pkt->list, &vsock->send_pkt_list);
+                        spin_unlock_bh(&vsock->send_pkt_list_lock);
+                        break;
+                }
+
+                if (head == vq->num) {
+                        spin_lock_bh(&vsock->send_pkt_list_lock);
+                        list_add(&pkt->list, &vsock->send_pkt_list);
+                        spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+                        /* We cannot finish yet if more buffers snuck in while
+                         * re-enabling notify.
+                         */
+                        if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
+                                vhost_disable_notify(&vsock->dev, vq);
+                                continue;
+                        }
+                        break;
+                }
+
+                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, sizeof(pkt->hdr) + pkt->len);
+                added = true;
+
+                if (pkt->reply) {
+                        int val;
+
+                        val = atomic_dec_return(&vsock->queued_replies);
+
+                        /* Do we have resources to resume tx processing? */
+                        if (val + 1 == tx_vq->num)
+                                restart_tx = true;
+                }
+
+                virtio_transport_free_pkt(pkt);
+        }
+        if (added)
+                vhost_signal(&vsock->dev, vq);
+
+out:
+        mutex_unlock(&vq->mutex);
+
+        if (restart_tx)
+                vhost_poll_queue(&tx_vq->poll);
+}
+
+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];
+
+        vhost_transport_do_send_pkt(vsock, vq);
+}
+
+static int
+vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt)
+{
+        struct vhost_vsock *vsock;
+        struct vhost_virtqueue *vq;
+        int len = pkt->len;
+
+        /* Find the vhost_vsock according to guest context id  */
+        vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid));
+        if (!vsock) {
+                virtio_transport_free_pkt(pkt);
+                return -ENODEV;
+        }
+
+        vq = &vsock->vqs[VSOCK_VQ_RX];
+
+        if (pkt->reply)
+                atomic_inc(&vsock->queued_replies);
+
+        spin_lock_bh(&vsock->send_pkt_list_lock);
+        list_add_tail(&pkt->list, &vsock->send_pkt_list);
+        spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+        vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
+        return len;
+}
+
+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;
+}
+
+/* Is there space left for replies to rx packets? */
+static bool vhost_vsock_more_replies(struct vhost_vsock *vsock)
+{
+        struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX];
+        int val;
+
+        smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
+        val = atomic_read(&vsock->queued_replies);
+
+        return val < vq->num;
+}
+
+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;
+
+        mutex_lock(&vq->mutex);
+
+        if (!vq->private_data)
+                goto out;
+
+        vhost_disable_notify(&vsock->dev, vq);
+        for (;;) {
+                if (!vhost_vsock_more_replies(vsock)) {
+                        /* Stop tx until the device processes already
+                         * pending replies.  Leave tx virtqueue
+                         * callbacks disabled.
+                         */
+                        goto no_more_replies;
+                }
+
+                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;
+                        }
+                        break;
+                }
+
+                pkt = vhost_vsock_alloc_pkt(vq, out, in);
+                if (!pkt) {
+                        vq_err(vq, "Faulted on pkt\n");
+                        continue;
+                }
+
+                /* Only accept correctly addressed packets */
+                if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
+                        virtio_transport_recv_pkt(pkt);
+                else
+                        virtio_transport_free_pkt(pkt);
+
+                vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
+                added = true;
+        }
+
+no_more_replies:
+        if (added)
+                vhost_signal(&vsock->dev, vq);
+
+out:
+        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_start(struct vhost_vsock *vsock)
+{
+        size_t i;
+        int ret;
+
+        mutex_lock(&vsock->dev.mutex);
+
+        ret = vhost_dev_check_owner(&vsock->dev);
+        if (ret)
+                goto err;
+
+        for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
+                struct vhost_virtqueue *vq = &vsock->vqs[i];
+
+                mutex_lock(&vq->mutex);
+
+                if (!vhost_vq_access_ok(vq)) {
+                        ret = -EFAULT;
+                        mutex_unlock(&vq->mutex);
+                        goto err_vq;
+                }
+
+                if (!vq->private_data) {
+                        vq->private_data = vsock;
+                        vhost_vq_init_access(vq);
+                }
+
+                mutex_unlock(&vq->mutex);
+        }
+
+        mutex_unlock(&vsock->dev.mutex);
+        return 0;
+
+err_vq:
+        for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
+                struct vhost_virtqueue *vq = &vsock->vqs[i];
+
+                mutex_lock(&vq->mutex);
+                vq->private_data = NULL;
+                mutex_unlock(&vq->mutex);
+        }
+err:
+        mutex_unlock(&vsock->dev.mutex);
+        return ret;
+}
+
+static int vhost_vsock_stop(struct vhost_vsock *vsock)
+{
+        size_t i;
+        int ret;
+
+        mutex_lock(&vsock->dev.mutex);
+
+        ret = vhost_dev_check_owner(&vsock->dev);
+        if (ret)
+                goto err;
+
+        for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
+                struct vhost_virtqueue *vq = &vsock->vqs[i];
+
+                mutex_lock(&vq->mutex);
+                vq->private_data = NULL;
+                mutex_unlock(&vq->mutex);
+        }
+
+err:
+        mutex_unlock(&vsock->dev.mutex);
+        return ret;
+}
+
+static void vhost_vsock_free(struct vhost_vsock *vsock)
+{
+        if (is_vmalloc_addr(vsock))
+                vfree(vsock);
+        else
+                kfree(vsock);
+}
+
+static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
+{
+        struct vhost_virtqueue **vqs;
+        struct vhost_vsock *vsock;
+        int ret;
+
+        /* This struct is large and allocation could fail, fall back to vmalloc
+         * if there is no other way.
+         */
+        vsock = kzalloc(sizeof(*vsock), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
+        if (!vsock) {
+                vsock = vmalloc(sizeof(*vsock));
+                if (!vsock)
+                        return -ENOMEM;
+        }
+
+        vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
+        if (!vqs) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        atomic_set(&vsock->queued_replies, 0);
+
+        vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
+        vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
+        vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
+        vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
+
+        vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs));
+
+        file->private_data = vsock;
+        spin_lock_init(&vsock->send_pkt_list_lock);
+        INIT_LIST_HEAD(&vsock->send_pkt_list);
+        vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
+
+        spin_lock_bh(&vhost_vsock_lock);
+        list_add_tail(&vsock->list, &vhost_vsock_list);
+        spin_unlock_bh(&vhost_vsock_lock);
+        return 0;
+
+out:
+        vhost_vsock_free(vsock);
+        return ret;
+}
+
+static void vhost_vsock_flush(struct vhost_vsock *vsock)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++)
+                if (vsock->vqs[i].handle_kick)
+                        vhost_poll_flush(&vsock->vqs[i].poll);
+        vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
+}
+
+static void vhost_vsock_reset_orphans(struct sock *sk)
+{
+        struct vsock_sock *vsk = vsock_sk(sk);
+
+        /* vmci_transport.c doesn't take sk_lock here either.  At least we're
+         * under vsock_table_lock so the sock cannot disappear while we're
+         * executing.
+         */
+
+        if (!vhost_vsock_get(vsk->local_addr.svm_cid)) {
+                sock_set_flag(sk, SOCK_DONE);
+                vsk->peer_shutdown = SHUTDOWN_MASK;
+                sk->sk_state = SS_UNCONNECTED;
+                sk->sk_err = ECONNRESET;
+                sk->sk_error_report(sk);
+        }
+}
+
+static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
+{
+        struct vhost_vsock *vsock = file->private_data;
+
+        spin_lock_bh(&vhost_vsock_lock);
+        list_del(&vsock->list);
+        spin_unlock_bh(&vhost_vsock_lock);
+
+        /* Iterating over all connections for all CIDs to find orphans is
+         * inefficient.  Room for improvement here. */
+        vsock_for_each_connected_socket(vhost_vsock_reset_orphans);
+
+        vhost_vsock_stop(vsock);
+        vhost_vsock_flush(vsock);
+        vhost_dev_stop(&vsock->dev);
+
+        spin_lock_bh(&vsock->send_pkt_list_lock);
+        while (!list_empty(&vsock->send_pkt_list)) {
+                struct virtio_vsock_pkt *pkt;
+
+                pkt = list_first_entry(&vsock->send_pkt_list,
+                                struct virtio_vsock_pkt, list);
+                list_del_init(&pkt->list);
+                virtio_transport_free_pkt(pkt);
+        }
+        spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+        vhost_dev_cleanup(&vsock->dev, false);
+        kfree(vsock->dev.vqs);
+        vhost_vsock_free(vsock);
+        return 0;
+}
+
+static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
+{
+        struct vhost_vsock *other;
+
+        /* Refuse reserved CIDs */
+        if (guest_cid <= VMADDR_CID_HOST ||
+            guest_cid == U32_MAX)
+                return -EINVAL;
+
+        /* 64-bit CIDs are not yet supported */
+        if (guest_cid > U32_MAX)
+                return -EINVAL;
+
+        /* Refuse if CID is already in use */
+        other = vhost_vsock_get(guest_cid);
+        if (other && other != vsock)
+                return -EADDRINUSE;
+
+        spin_lock_bh(&vhost_vsock_lock);
+        vsock->guest_cid = guest_cid;
+        spin_unlock_bh(&vhost_vsock_lock);
+
+        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 < ARRAY_SIZE(vsock->vqs); i++) {
+                vq = &vsock->vqs[i];
+                mutex_lock(&vq->mutex);
+                vq->acked_features = features;
+                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 guest_cid;
+        u64 features;
+        int start;
+        int r;
+
+        switch (ioctl) {
+        case VHOST_VSOCK_SET_GUEST_CID:
+                if (copy_from_user(&guest_cid, argp, sizeof(guest_cid)))
+                        return -EFAULT;
+                return vhost_vsock_set_cid(vsock, guest_cid);
+        case VHOST_VSOCK_SET_RUNNING:
+                if (copy_from_user(&start, argp, sizeof(start)))
+                        return -EFAULT;
+                if (start)
+                        return vhost_vsock_start(vsock);
+                else
+                        return vhost_vsock_stop(vsock);
+        case VHOST_GET_FEATURES:
+                features = VHOST_VSOCK_FEATURES;
+                if (copy_to_user(argp, &features, sizeof(features)))
+                        return -EFAULT;
+                return 0;
+        case VHOST_SET_FEATURES:
+                if (copy_from_user(&features, argp, 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 struct virtio_transport vhost_transport = {
+        .transport = {
+                .get_local_cid            = vhost_transport_get_local_cid,
+
+                .init                     = virtio_transport_do_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,
+        },
+
+        .send_pkt = vhost_transport_send_pkt,
+};
+
+static int __init vhost_vsock_init(void)
+{
+        int ret;
+
+        ret = vsock_core_init(&vhost_transport.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 ");