Hi Yu, FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant. tree: https://gitee.com/openeuler/kernel.git OLK-5.10 head: d96e94294726506c2893c3a71305c65168c22526 commit: 8a7e6f51a756aa6e88ebd5da8a5f3b6744cd07b5 [27211/30000] KVM: x86: Introduce kvm_post_set_cr4 to post handle the CR4 emulation config: x86_64-rhel-8.3-rust (https://download.01.org/0day-ci/archive/20240828/202408281404.nd7rLidC-lkp@i...) compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240828/202408281404.nd7rLidC-lkp@i...) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202408281404.nd7rLidC-lkp@intel.com/ All warnings (new ones prefixed by >>): arch/x86/kvm/x86.c:893:6: warning: no previous prototype for function 'kvm_post_set_cr0' [-Wmissing-prototypes] 893 | void kvm_post_set_cr0(struct kvm_vcpu *vcpu, unsigned long old_cr0, unsigned long cr0) | ^ arch/x86/kvm/x86.c:893:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 893 | void kvm_post_set_cr0(struct kvm_vcpu *vcpu, unsigned long old_cr0, unsigned long cr0) | ^ | static

...

arch/x86/kvm/x86.c:1076:6: warning: no previous prototype for function 'kvm_post_set_cr4' [-Wmissing-prototypes] 1076 | void kvm_post_set_cr4(struct kvm_vcpu *vcpu, unsigned long old_cr4, unsigned long cr4) | ^ arch/x86/kvm/x86.c:1076:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1076 | void kvm_post_set_cr4(struct kvm_vcpu *vcpu, unsigned long old_cr4, unsigned long cr4) | ^ | static 2 warnings generated.

vim +/kvm_post_set_cr4 +1076 arch/x86/kvm/x86.c 1075

1076 void kvm_post_set_cr4(struct kvm_vcpu *vcpu, unsigned long old_cr4, unsigned long cr4) 1077 { 1078 unsigned long mmu_role_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE | 1079 X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE; 1080 1081 if (((cr4 ^ old_cr4) & mmu_role_bits) || 1082 (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE))) 1083 kvm_mmu_reset_context(vcpu); 1084 } 1085

-- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki