How to generate kernel header files like Ubuntu prebuilt standard kernel header files?

Ubuntu-12.0.4-lts with virtualbox installed building with latest linux kernel tree. When make install, it always spits below error when build virtualbox modules

run-parts: executing /etc/kernel/postinst.d/dkms 3.12.0+ /boot/vmlinuz-3.12.0+ ERROR (dkms apport): kernel package linux-headers-3.12.0+ is not supported

The Ubuntu system prebuilt kernel header is as below:

#ls /usr/src/linux-headers-3.2.0-23

arch  block  crypto  Documentation  drivers  firmware  fs  include
init  ipc  Kbuild  Kconfig  kernel  lib  Makefile  mm  net  samples

scripts security sound tools ubuntu usr virt

But the latest kernel headers looks like this, and building virtualbox modules still bad

# cd linux-3.12.0 && make headers_install
# cat usr/include/
include

Can I ask how to generate kernel headers with latest linux kernel tree to successfully build virtualbox modules?

thanks

?????????,??????????

--bill