reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=ca9ddf0b7d74a71b6d71ea5355825922b89f5fd7
        git remote add kvm https://git.kernel.org/pub/scm/virt/kvm/kvm.git
        git fetch --no-tags kvm queue
        git checkout ca9ddf0b7d74a71b6d71ea5355825922b89f5fd7
        # 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/