vhost_vring_ioctl
r = vhost_vring_ioctl(&n->dev, ioctl, argp);
r = vhost_vring_ioctl(&vs->dev, ioctl, argp);
r = vhost_vring_ioctl(&n->dev, ioctl, argp);
r = vhost_vring_ioctl(&v->vdev, cmd, argp);
EXPORT_SYMBOL_GPL(vhost_vring_ioctl);
long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);