reproduce (this is a W=1 build):
        # https://github.com/avpatel/linux/commit/d031623b217ef2181892909a4ceb47568fe73a1e
        git remote add avpatel https://github.com/avpatel/linux.git
        git fetch --no-tags avpatel riscv_trace_support_v2
        git checkout d031623b217ef2181892909a4ceb47568fe73a1e

        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=$HOME/0day COMPILER=gcc-10.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash drivers/hwtracing/rvtrace/