Hi Haiwei, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 325d0eab4f31c6240b59d5b2b8042c88f59405b5 commit: 0f990222108d214a0924d920e6095b58107d7b59 KVM: Check the allocation of pv cpu mask date: 9 days ago config: i386-randconfig-a003-20200920 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): git checkout 0f990222108d214a0924d920e6095b58107d7b59 # save the attached .config to linux build tree make W=1 ARCH=i386 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 >>): arch/x86/kernel/kvm.c: In function 'kvm_alloc_cpumask': 802 | apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/x86/kernel/kvm.c:802:35: note: each undeclared identifier is reported only once for each function it appears in # 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 0f990222108d214a0924d920e6095b58107d7b59 vim +/kvm_send_ipi_mask_allbutself +802 arch/x86/kernel/kvm.c 792 793 if (alloc) 794 for_each_possible_cpu(cpu) { 795 if (!zalloc_cpumask_var_node( 796 per_cpu_ptr(&__pv_cpu_mask, cpu), 797 GFP_KERNEL, cpu_to_node(cpu))) { 798 goto zalloc_cpumask_fail; 799 } 800 } 801 803 pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others; 804 return 0; 805 806 zalloc_cpumask_fail: 807 kvm_free_pv_cpu_mask(); 808 return -ENOMEM; 809 } 810 arch_initcall(kvm_alloc_cpumask); 811 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org