On Fri, May 23, 2014 at 12:57 AM, Mathew Li <mathew.li100@xxxxxxxxx> wrote: > Hi All, > > I want to learn KVM code. Apologies for asking really simple > questions. I have Ubuntu 12.04 32bit installed on my laptop. As I > understand there are two modules of the KVM. One is called kvm.ko and > other arch specific e.g. in my case it is kvm-intel.ko. These modules > are already present in my system. I can do modinfo and it lists them. > > What I want to do is modify KVM code to add print statements to > understand things better. But I don't know what code to modify and how > to rebuild these two modules for my system, so that they have my print > statements. Could you please guide me what code do I need to download > and how to compile that to get the modules regenerated for my system? > If I need to download the whole Linux kernel then where in Linux > kernel KVM code lives? I don't want to compile the whole linux kernel, > I just want to compile these modules for my system. > > Thanks a lot for any help you could provide. > > Thanks! > Matt If you are using the latest kernel, then arch/x86/kvm and virt/kvm are the two directories you should look at, and also some header files are under the include/linux directory. Since kvm is a part of the mainline kernel, I don't think you need to download anything else other than the mainline kernel. But, to use kvm, I think you should install Qemu, which is a user-level tool. If you compile kvm as a kernel module, then each time you insert your printk statements, you don't need to compile the whole kernel, just compile the specific directory you have made changes in. For example, if you have changed arch/x86/kvm directory, you can use the command: `make modules SUBDIRS=arch/x86/kvm`. Once you are done, just copy the generated module: kvm.ko, kvm-intel.ko to /lib/modules/your-kernel-version/kernel/arch/x86/kvm/. Remove the existing kvm.ko/kvm-intel.ko, and install the new modules. -Jidong -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
