Hi Matthew, I love your patch! Perhaps something to improve: [auto build test WARNING on v5.18-rc4] [cannot apply to s390/features kvms390/next awilliam-vfio/next next-20220427] [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/intel-lab-lkp/linux/commits/Matthew-Rosato/KVM-s390-enable-zPCI-for-interpretive-execution/20220427-041853 base: af2d861d4cd2a4da5137f795ee3509e6f944a25b config: s390-defconfig (https://download.01.org/0day-ci/archive/20220427/202204271653.1ZoYsV9W-lkp@xxxxxxxxx/config) compiler: s390-linux-gcc (GCC) 11.3.0 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/intel-lab-lkp/linux/commit/e6d8c620090a7b184afdf5b5123d10ac45776eaf git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Matthew-Rosato/KVM-s390-enable-zPCI-for-interpretive-execution/20220427-041853 git checkout e6d8c620090a7b184afdf5b5123d10ac45776eaf # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash arch/s390/kvm/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> arch/s390/kvm/pci.c:14:5: warning: no previous prototype for 'kvm_s390_pci_dev_open' [-Wmissing-prototypes] 14 | int kvm_s390_pci_dev_open(struct zpci_dev *zdev) | ^~~~~~~~~~~~~~~~~~~~~ >> arch/s390/kvm/pci.c:29:6: warning: no previous prototype for 'kvm_s390_pci_dev_release' [-Wmissing-prototypes] 29 | void kvm_s390_pci_dev_release(struct zpci_dev *zdev) | ^~~~~~~~~~~~~~~~~~~~~~~~ vim +/kvm_s390_pci_dev_open +14 arch/s390/kvm/pci.c 13 > 14 int kvm_s390_pci_dev_open(struct zpci_dev *zdev) 15 { 16 struct kvm_zdev *kzdev; 17 18 kzdev = kzalloc(sizeof(struct kvm_zdev), GFP_KERNEL); 19 if (!kzdev) 20 return -ENOMEM; 21 22 kzdev->zdev = zdev; 23 zdev->kzdev = kzdev; 24 25 return 0; 26 } 27 EXPORT_SYMBOL_GPL(kvm_s390_pci_dev_open); 28 > 29 void kvm_s390_pci_dev_release(struct zpci_dev *zdev) -- 0-DAY CI Kernel Test Service https://01.org/lkp