where is headers_install in KBUILD

[YU Bo]

Hello,
Now i want to compile kernel and test userspace program fastly and i find
a good guide link:
https://vincent.bernat.ch/en/blog/2014-eudyptula-boot
In the article, author compile kernel with KBUILD(custom install vmlinux...)

1. export KBUILD_OPTPUT=$HOME/src/kernel-build
Is this generate a copy of linux kernel source, right?
2. edit .config and make
3. sudo make modules_install install {INSTALL_MOD_PATH,INSTALL_PATH}=$HOME/src/kernel-dev

Ok, I did it and booted a VM with qemu, it is cool.
But, my "question" is:  when i test some program which needs kernel headers,
where to install those headers file?
In Documention/kbuild/headers_install.rst, i learn it :
	make headers_install INSTALL_HDR_PATH=/usr
In my case, Is it ok to do that?I do not think it will work.
May i:
	make headers_install INSTALL_HDR_PATH=$HOME/src/kernel-headers
is it Ok?

Thank you very much!
Bo