reproduce (this is a W=1 build):
        # https://github.com/xinli-intel/linux-fred-public/commit/d5ef033653748ddab562afec7917735cee02dc42
        git remote add xinli-intel-fred-public https://github.com/xinli-intel/linux-fred-public.git
        git fetch --no-tags xinli-intel-fred-public fred-kvm-v10
        git checkout d5ef033653748ddab562afec7917735cee02dc42
        # apt-get install sparse
        # sparse: v0.6.5-rc1

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=x86_64 olddefconfig
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/kvm/