tree: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue head: c1dc20e254b421a2463da7f053b37d822788224a commit: 1fb7f06d81d209b3ad57a9720808ccaf1c9d55f6 [155/222] KVM: SVM: hyper-v: Remote TLB flush for SVM config: x86_64-allmodconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=1fb7f06d81d209... git remote add kvm https://git.kernel.org/pub/scm/virt/kvm/kvm.git git fetch --no-tags kvm queue git checkout 1fb7f06d81d209b3ad57a9720808ccaf1c9d55f6 # save the attached .config to linux build tree make W=1 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 >>): In file included from arch/x86/kvm/svm/svm.c:47: arch/x86/kvm/svm/svm_onhyperv.h: In function 'svm_hv_hardware_setup': 49 | svm_x86_ops.tlb_remote_flush = hv_remote_flush_tlb; | ^~~~~~~~~~~~~~~~~~~ | svm_flush_tlb arch/x86/kvm/svm/svm_onhyperv.h:49:34: note: each undeclared identifier is reported only once for each function it appears in 51 | hv_remote_flush_tlb_with_range; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +49 arch/x86/kvm/svm/svm_onhyperv.h 43 44 static inline void svm_hv_hardware_setup(void) 45 { 46 if (npt_enabled && 47 ms_hyperv.nested_features & HV_X64_NESTED_ENLIGHTENED_TLB) { 48 pr_info("kvm: Hyper-V enlightened NPT TLB flush enabled\n"); 50 svm_x86_ops.tlb_remote_flush_with_range = 52 } 53 } 54 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org