First we need to get kernel source code. It can easily get with
$ apt-get install linux-source-$(uname -r)
after that, this command will download kernel source code to
usr/src/linux-source....
. The source code should inside a .tar file and we need to untar.
$ ls usr/src/linux-source....
$ sudo tar -xf linux-source......tar.b2
$ cd linux-source...
Now we can modify KVM. After modification we need to compile the KVM module. To do this:
sudo make modules -j6 SUBDIRS=arch/x86/kvm/
sudo make -j6 M=arch/x86/kvm/
after that we need to change kernel module, first remove the kvm module
$ sudo rmmod kvm_intel; sudo rmmod kvm
after add kernel module to system
$ sudo insmod arch/x86/kvm/kvm.ko; sudo insmod arch/x86/kvm/kvm-intel.ko