Hi Abhishek, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on tip/auto-latest] [also build test WARNING on linux/master tip/x86/core kvm/linux-next linus/master v5.8-rc3 next-20200702] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Abhishek-Bhardwaj/x86-speculation-l1tf-Add-KConfig-for-setting-the-L1D-cache-flush-mode/20200703-002135 base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 7e44a91e0445a854af5d34ca0f5baceccd518e73 config: x86_64-defconfig (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 003a086ffc0d1affbb8300b36225fb8150a2d40a) 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 # 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 All warnings (new ones prefixed by >>): >> arch/x86/kernel/cpu/bugs.c:1402:6: warning: 'CONFIG_KVM_VMENTRY_L1D_FLUSH' is not defined, evaluates to 0 [-Wundef] #if (CONFIG_KVM_VMENTRY_L1D_FLUSH == 1) ^ arch/x86/kernel/cpu/bugs.c:1404:8: warning: 'CONFIG_KVM_VMENTRY_L1D_FLUSH' is not defined, evaluates to 0 [-Wundef] #elif (CONFIG_KVM_VMENTRY_L1D_FLUSH == 2) ^ arch/x86/kernel/cpu/bugs.c:1406:8: warning: 'CONFIG_KVM_VMENTRY_L1D_FLUSH' is not defined, evaluates to 0 [-Wundef] #elif (CONFIG_KVM_VMENTRY_L1D_FLUSH == 3) ^ 3 warnings generated. vim +/CONFIG_KVM_VMENTRY_L1D_FLUSH +1402 arch/x86/kernel/cpu/bugs.c 1396 1397 /* Default mitigation for L1TF-affected CPUs */ 1398 enum l1tf_mitigations l1tf_mitigation __ro_after_init = L1TF_MITIGATION_FLUSH; 1399 #if IS_ENABLED(CONFIG_KVM_INTEL) 1400 EXPORT_SYMBOL_GPL(l1tf_mitigation); 1401 #endif > 1402 #if (CONFIG_KVM_VMENTRY_L1D_FLUSH == 1) 1403 enum vmx_l1d_flush_state l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_NEVER; 1404 #elif (CONFIG_KVM_VMENTRY_L1D_FLUSH == 2) 1405 enum vmx_l1d_flush_state l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_COND; 1406 #elif (CONFIG_KVM_VMENTRY_L1D_FLUSH == 3) 1407 enum vmx_l1d_flush_state l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_ALWAYS; 1408 #else 1409 enum vmx_l1d_flush_state l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_AUTO; 1410 #endif 1411 EXPORT_SYMBOL_GPL(l1tf_vmx_mitigation); 1412 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org