reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://github.com/agraf/linux-2.6/commit/dc3f33bb180826ee0bcd0ecc79cad842ff3ffccf
        git remote add agraf-2.6 https://github.com/agraf/linux-2.6.git
        git fetch --no-tags agraf-2.6 kvm-kho-gmem-test
        git checkout dc3f33bb180826ee0bcd0ecc79cad842ff3ffccf
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash arch/arm64/kvm/ virt/