VSOCK: Introduce vhost-vsock.ko
authorAsias He <asias@redhat.com>
Wed, 2 Dec 2015 06:44:02 +0000 (14:44 +0800)
committerDavid S. Miller <davem@davemloft.net>
Thu, 3 Dec 2015 20:05:55 +0000 (15:05 -0500)
VM sockets vhost transport implementation. This module runs in host
kernel.

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/vhost/vsock.c [new file with mode: 0644]
drivers/vhost/vsock.h [new file with mode: 0644]

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
new file mode 100644 (file)
index 0000000..65b1cf8
--- /dev/null
@@ -0,0 +1,631 @@
+/*
+ * 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/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;
+};
+
+static u32 vhost_transport_get_local_cid(void)
+{
+       u32 cid = VHOST_VSOCK_DEFAULT_HOST_CID;
+       return 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;
+                       }
+                       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? */
+               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) {
+               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_DGRAM)
+               pkt->len = le32_to_cpu(pkt->hdr.len) & 0XFFFF;
+       else 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);
+}
+
+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;
+                       }
+                       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;
+               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 (file)
index 0000000..0ddb107
--- /dev/null
@@ -0,0 +1,4 @@
+#ifndef VHOST_VSOCK_H
+#define VHOST_VSOCK_H
+#define VHOST_VSOCK_SET_GUEST_CID _IOW(VHOST_VIRTIO, 0x60, __u32)
+#endif