Hi Claudio, I love your patch! Yet something to improve: [auto build test ERROR on kvm/queue] [also build test ERROR on v5.17-rc2 next-20220204] [cannot apply to kvms390/next s390/features] [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/Claudio-Imbrenda/KVM-s390-pv-implement-lazy-destroy-for-reboot/20220204-235609 base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue config: s390-randconfig-r044-20220131 (https://download.01.org/0day-ci/archive/20220205/202202050525.5A9HirW8-lkp@intel.com/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a73e4ce6a59b01f0e37037761c1e6889d539d233) 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 # install s390 cross compiling tool for clang build # apt-get install binutils-s390x-linux-gnu # https://github.com/0day-ci/linux/commit/9ee65f25ad996d38f6935360c99a89e72024174b git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Claudio-Imbrenda/KVM-s390-pv-implement-lazy-destroy-for-reboot/20220204-235609 git checkout 9ee65f25ad996d38f6935360c99a89e72024174b # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang 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 All errors (new ones prefixed by >>): In file included from arch/s390/kvm/pv.c:9: In file included from include/linux/kvm_host.h:41: In file included from include/linux/kvm_para.h:5: In file included from include/uapi/linux/kvm_para.h:37: In file included from arch/s390/include/asm/kvm_para.h:25: In file included from arch/s390/include/asm/diag.h:12: In file included from include/linux/if_ether.h:19: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __raw_readb(PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x)) ^ include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16' #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) ^ In file included from arch/s390/kvm/pv.c:9: In file included from include/linux/kvm_host.h:41: In file included from include/linux/kvm_para.h:5: In file included from include/uapi/linux/kvm_para.h:37: In file included from arch/s390/include/asm/kvm_para.h:25: In file included from arch/s390/include/asm/diag.h:12: In file included from include/linux/if_ether.h:19: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32' #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x)) ^ In file included from arch/s390/kvm/pv.c:9: In file included from include/linux/kvm_host.h:41: In file included from include/linux/kvm_para.h:5: In file included from include/uapi/linux/kvm_para.h:37: In file included from arch/s390/include/asm/kvm_para.h:25: In file included from arch/s390/include/asm/diag.h:12: In file included from include/linux/if_ether.h:19: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:75: include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ >> arch/s390/kvm/pv.c:255:3: error: implicit declaration of function 'mmu_notifier_register' [-Werror,-Wimplicit-function-declaration] mmu_notifier_register(&kvm->arch.pv.mmu_notifier, kvm->mm); ^ arch/s390/kvm/pv.c:255:3: note: did you mean 'mmu_notifier_release'? include/linux/mmu_notifier.h:679:20: note: 'mmu_notifier_release' declared here static inline void mmu_notifier_release(struct mm_struct *mm) ^ 12 warnings and 1 error generated. vim +/mmu_notifier_register +255 arch/s390/kvm/pv.c 210 211 int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc) 212 { 213 struct uv_cb_cgc uvcb = { 214 .header.cmd = UVC_CMD_CREATE_SEC_CONF, 215 .header.len = sizeof(uvcb) 216 }; 217 int cc, ret; 218 u16 dummy; 219 220 ret = kvm_s390_pv_alloc_vm(kvm); 221 if (ret) 222 return ret; 223 224 /* Inputs */ 225 uvcb.guest_stor_origin = 0; /* MSO is 0 for KVM */ 226 uvcb.guest_stor_len = kvm->arch.pv.guest_len; 227 uvcb.guest_asce = kvm->arch.gmap->asce; 228 uvcb.guest_sca = (unsigned long)kvm->arch.sca; 229 uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base; 230 uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var; 231 232 cc = uv_call_sched(0, (u64)&uvcb); 233 *rc = uvcb.header.rc; 234 *rrc = uvcb.header.rrc; 235 KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x", 236 uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc); 237 238 /* Outputs */ 239 kvm->arch.pv.handle = uvcb.guest_handle; 240 241 atomic_inc(&kvm->mm->context.protected_count); 242 if (cc) { 243 if (uvcb.header.rc & UVC_RC_NEED_DESTROY) { 244 kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy); 245 } else { 246 atomic_dec(&kvm->mm->context.protected_count); 247 kvm_s390_pv_dealloc_vm(kvm); 248 } 249 return -EIO; 250 } 251 kvm->arch.gmap->guest_handle = uvcb.guest_handle; 252 /* Add the notifier only once. No races because we hold kvm->lock */ 253 if (kvm->arch.pv.mmu_notifier.ops != &kvm_s390_pv_mmu_notifier_ops) { 254 kvm->arch.pv.mmu_notifier.ops = &kvm_s390_pv_mmu_notifier_ops; > 255 mmu_notifier_register(&kvm->arch.pv.mmu_notifier, kvm->mm); 256 } 257 return 0; 258 } 259 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org