Hi Peter, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on vhost/linux-next] [also build test WARNING on linus/master v5.7-rc7] [cannot apply to kvm/linux-next tip/auto-latest linux/master next-20200522] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Peter-Xu/KVM-Dirty-ring-interfac... base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next config: x86_64-allyesconfig (attached as .config) compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0 reproduce (this is a W=1 build): # 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: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): bool kvm_dirty_ring_full(struct kvm_dirty_ring *ring) ^~~~~~~~~~~~~~~~~~~ -- arch/x86/kvm/vmx/vmx.c: In function 'init_rmode_identity_map': kvm_pfn_t identity_map_pfn; ^~~~~~~~~~~~~~~~ vim +/kvm_dirty_ring_full +33 arch/x86/kvm/../../../virt/kvm/dirty_ring.c 32 34 { 35 return kvm_dirty_ring_used(ring) >= ring->size; 36 } 37 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org