tree: https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git sev-es-client-tip-5.9 head: 7e2e0f5fb47e16dec0e6b81ce2ee36abb4c28eb9 commit: d77c36d3ce62e768feca12a9e9d2a8ddef7be2f8 [49/76] x86/sev-es: Add Runtime #VC Exception Handler config: x86_64-randconfig-r002-20200818 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 790878f291fa5dc58a1c560cb6cc76fd1bfd1c5a) 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 git checkout d77c36d3ce62e768feca12a9e9d2a8ddef7be2f8 # 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 warnings (new ones prefixed by >>): DEFINE_IDTENTRY_VC_IST(exc_vmm_communication) ^ arch/x86/include/asm/idtentry.h:380:32: note: expanded from macro 'DEFINE_IDTENTRY_VC_IST' DEFINE_IDTENTRY_RAW_ERRORCODE(ist_##func) ^ <scratch space>:270:1: note: expanded from here ist_exc_vmm_communication ^ arch/x86/kernel/sev-es.c:594:1: note: declare 'static' if the function is not intended to be used outside of this translation unit arch/x86/include/asm/idtentry.h:380:2: note: expanded from macro 'DEFINE_IDTENTRY_VC_IST' DEFINE_IDTENTRY_RAW_ERRORCODE(ist_##func) ^ arch/x86/include/asm/idtentry.h:167:19: note: expanded from macro 'DEFINE_IDTENTRY_RAW_ERRORCODE' __visible noinstr void func(struct pt_regs *regs, unsigned long error_code) ^ 1 warning generated. # https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git/commit/?id... git remote add joro https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git git fetch --no-tags joro sev-es-client-tip-5.9 git checkout d77c36d3ce62e768feca12a9e9d2a8ddef7be2f8 vim +/ist_exc_vmm_communication +594 arch/x86/kernel/sev-es.c 592 593 /* This handler runs on the #VC fall-back stack. It can cause further #VC exceptions */ 595 { 596 instrumentation_begin(); 597 panic("Can't handle #VC exception from unsupported context\n"); 598 instrumentation_end(); 599 } 600 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org