How to send/upload a file from Host OS to guest OS in KVM?(not folder sharing)

I have to make a configuration file available to guest OS running on top of KVM hyper-visor. I have already read about folder sharing options between host and guest in KVM with 'qemu' and 9P virtio support. I would like to know about any simple procedure which can help in one time file transfer from host to guest. Please let me know, how to transfer file while guest OS is running as well as a possible way to make the file available to guest OS by the time it starts running(like packaging the file and integrating with the disk-image if possible). Host OS will be linux.