Hi Jing, Thank you for the patch! Yet something to improve: [auto build test ERROR on d0732b0f8884d9cc0eca0082bbaef043f3fef7fb] url: https://github.com/0day-ci/linux/commits/Jing-Zhang/KVM-stats-Add-VM-dirt... base: d0732b0f8884d9cc0eca0082bbaef043f3fef7fb config: powerpc-allyesconfig (attached as .config) compiler: powerpc-linux-gcc (GCC) 10.3.0 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 # https://github.com/0day-ci/linux/commit/85679ee0cff16eaae940baba21e08ad6e... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jing-Zhang/KVM-stats-Add-VM-dirty_pages-stats-for-the-number-of-dirty-pages/20210811-063544 git checkout 85679ee0cff16eaae940baba21e08ad6e9944698 # save the attached .config to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash 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 >>): arch/powerpc/kvm/book3s_hv_rm_mmu.c: In function 'kvmppc_update_dirty_map': 112 | kvm->stat.generic.dirty_pages += npages; | ^~~ arch/powerpc/kvm/book3s_hv_rm_mmu.c:112:2: note: each undeclared identifier is reported only once for each function it appears in vim +/kvm +112 arch/powerpc/kvm/book3s_hv_rm_mmu.c 100 101 /* Update the dirty bitmap of a memslot */ 102 void kvmppc_update_dirty_map(const struct kvm_memory_slot *memslot, 103 unsigned long gfn, unsigned long psize) 104 { 105 unsigned long npages; 106 107 if (!psize || !memslot->dirty_bitmap) 108 return; 109 npages = (psize + PAGE_SIZE - 1) / PAGE_SIZE; 110 gfn -= memslot->base_gfn; 111 set_dirty_bits_atomic(memslot->dirty_bitmap, gfn, npages); 113 } 114 EXPORT_SYMBOL_GPL(kvmppc_update_dirty_map); 115 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org