reproduce (this is a W=1 build):
        # https://github.com/intel/tdx/commit/765f146fe3ca453ecbec8aaa4545f82f6878c488
        git remote add intel-tdx https://github.com/intel/tdx.git
        git fetch --no-tags intel-tdx guest-filter
        git checkout 765f146fe3ca453ecbec8aaa4545f82f6878c488
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/coco/tdx/