Hi Janakarajan, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on tip/x86/core] [also build test WARNING on v4.15] [cannot apply to kvm/linux-next next-20180202] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Janakarajan-Natarajan/Support-Perf-Extensions-on-AMD-KVM-guests/20180202-231344 reproduce: # apt-get install sparse make ARCH=x86_64 allmodconfig make C=1 CF=-D__CHECK_ENDIAN__ sparse warnings: (new ones prefixed by >>) >> arch/x86/kvm/cpuid.c:58:6: sparse: symbol 'perf_ext_supported' was not declared. Should it be Please review and possibly fold the followup patch. --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation