reproduce (this is a W=1 build):
        # https://github.com/sean-jc/linux/commit/bac6bf1a9360d8301e58c5ea06be70c71a665b75
        git remote add sean-jc https://github.com/sean-jc/linux
        git fetch --no-tags sean-jc x86/svm_handler_nospec
        git checkout bac6bf1a9360d8301e58c5ea06be70c71a665b75

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/kvm/