reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/commit/?id=844a375408e66647ee7b0c1ee710b6e5a60b59db
        git remote add arm-perf https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git
        git fetch --no-tags arm-perf kvm/protected-memory
        git checkout 844a375408e66647ee7b0c1ee710b6e5a60b59db

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash arch/arm64/