/* vhost_user.c */
int vhost_user_msg_handler(int vid, int fd);
int vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t perm);
-int vhost_user_host_notifier_ctrl(int vid, bool enable);
/* socket.c */
int read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds,