Hi David, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: f4e087c666f54559cb4e530af1fbfc9967e14a15 commit: 3d7746bea92530e8695258a3cf3ddec7a135edd6 x86/xen: Fix xen_hvm_smp_init() when vector callback not available date: 2 days ago config: x86_64-randconfig-a003-20210116 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 5b42fd8dd4e7e29125a09a41a33af7c9cb57d144) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 3d7746bea92530e8695258a3cf3ddec7a135edd6 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): nopvspin = true; ^ 1 error generated. vim +/nopvspin +77 arch/x86/xen/smp_hvm.c 68 69 void __init xen_hvm_smp_init(void) 70 { 71 smp_ops.smp_prepare_boot_cpu = xen_hvm_smp_prepare_boot_cpu; 72 smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus; 73 smp_ops.smp_cpus_done = xen_smp_cpus_done; 74 smp_ops.cpu_die = xen_hvm_cpu_die; 75 76 if (!xen_have_vector_callback) { --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org