[kbuild-all] [linux-stable-rc:linux-4.19.y 3355/9999] arch/arm/kvm/../../../virt/kvm/eventfd.c:48:1: warning: no previous prototype for 'kvm_arch_irqfd_allowed'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.19.y head: d694d4388e889e15298d8de938fb4e61e4df75bf commit: d5f6539381c765291f96b744549b2dfb688a3f4a [3355/9999] kvm: Check irqchip mode before assign irqfd config: arm-axm55xx_defconfig (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 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 git checkout d5f6539381c765291f96b744549b2dfb688a3f4a # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): 48 | kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args) | ^~~~~~~~~~~~~~~~~~~~~~ vim +/kvm_arch_irqfd_allowed +48 arch/arm/kvm/../../../virt/kvm/eventfd.c 46 47 bool __attribute__((weak)) 49 { 50 return true; 51 } 52 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org