Hi Uros, Thank you for the patch! Yet something to improve: [auto build test ERROR on tip/master] [also build test ERROR on next-20201215] [cannot apply to tip/x86/core kvm/linux-next v5.10] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Uros-Bizjak/x86-KVM-VMX-Introduc... base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git d1c29f5debd4633eb0e9ea1bc00aaad48b077a9b config: i386-tinyconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/60a11e7e63e120b5fd41b5346cf5a05ea... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Uros-Bizjak/x86-KVM-VMX-Introduce-and-use-try_cmpxchg64/20201216-024049 git checkout 60a11e7e63e120b5fd41b5346cf5a05ea71c7cb2 # 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 >>): ld: arch/x86/events/core.o: in function `x86_perf_event_update': ld: kernel/sched/clock.o: in function `sched_clock_local.constprop.0': ld: kernel/sched/clock.o: in function `sched_clock_cpu': clock.c:(.text+0x293): undefined reference to `cmpxchg8b_emu' ld: kernel/events/core.o: in function `perf_swevent_set_period': core.c:(.text+0x8cbb): undefined reference to `cmpxchg8b_emu' ld: fs/inode.o:inode.c:(.text+0x10ca): more undefined references to `cmpxchg8b_emu' follow --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org