reproduce:
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # apt-get install sparse
        # sparse version: v0.6.4-47-g365b9520-dirty
        # https://github.com/kvm-riscv/linux/commit/48cf9d76ece38e3855f9a05929a0c094c2933c2d
        git remote add kvm-riscv https://github.com/kvm-riscv/linux.git
        git fetch --no-tags kvm-riscv riscv_kvm_queue
        git checkout 48cf9d76ece38e3855f9a05929a0c094c2933c2d
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        ~/lkp-tests/kbuild/make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=riscv olddefconfig
        ~/lkp-tests/kbuild/make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=riscv SHELL=/bin/bash arch/riscv/kvm/