tree: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue head: ce41d078aaa9cf15cbbb4a42878cc6160d76525e commit: ce41d078aaa9cf15cbbb4a42878cc6160d76525e [210/210] KVM: x86: synthesize CPUID leaf 0x80000021h if useful config: x86_64-randconfig-a014 (https://download.01.org/0day-ci/archive/20220310/202203101604.2rV6WBqW-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 276ca87382b8f16a65bddac700202924228982f6) 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://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=ce41d078aaa9cf15cbbb4a42878cc6160d76525e git remote add kvm https://git.kernel.org/pub/scm/virt/kvm/kvm.git git fetch --no-tags kvm queue git checkout ce41d078aaa9cf15cbbb4a42878cc6160d76525e # 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=x86_64 SHELL=/bin/bash arch/x86/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/x86/kvm/cpuid.c:739:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough] default: ^ arch/x86/kvm/cpuid.c:739:2: note: insert 'break;' to avoid fall-through default: ^ break; 1 warning generated. vim +739 arch/x86/kvm/cpuid.c e53c95e8d41ef9 Sean Christopherson 2020-03-02 707 e53c95e8d41ef9 Sean Christopherson 2020-03-02 708 static struct kvm_cpuid_entry2 *do_host_cpuid(struct kvm_cpuid_array *array, aa10a7dc8858f6 Sean Christopherson 2020-03-02 709 u32 function, u32 index) 00b27a3efb1160 Avi Kivity 2011-11-23 710 { e53c95e8d41ef9 Sean Christopherson 2020-03-02 711 struct kvm_cpuid_entry2 *entry; e53c95e8d41ef9 Sean Christopherson 2020-03-02 712 e53c95e8d41ef9 Sean Christopherson 2020-03-02 713 if (array->nent >= array->maxnent) aa10a7dc8858f6 Sean Christopherson 2020-03-02 714 return NULL; e53c95e8d41ef9 Sean Christopherson 2020-03-02 715 e53c95e8d41ef9 Sean Christopherson 2020-03-02 716 entry = &array->entries[array->nent++]; aa10a7dc8858f6 Sean Christopherson 2020-03-02 717 2746a6b72ab9a9 Paolo Bonzini 2021-10-28 718 memset(entry, 0, sizeof(*entry)); 00b27a3efb1160 Avi Kivity 2011-11-23 719 entry->function = function; 00b27a3efb1160 Avi Kivity 2011-11-23 720 entry->index = index; 2746a6b72ab9a9 Paolo Bonzini 2021-10-28 721 switch (function & 0xC0000000) { 2746a6b72ab9a9 Paolo Bonzini 2021-10-28 722 case 0x40000000: 2746a6b72ab9a9 Paolo Bonzini 2021-10-28 723 /* Hypervisor leaves are always synthesized by __do_cpuid_func. */ 2746a6b72ab9a9 Paolo Bonzini 2021-10-28 724 return entry; 2746a6b72ab9a9 Paolo Bonzini 2021-10-28 725 ce41d078aaa9cf Paolo Bonzini 2021-10-21 726 case 0x80000000: ce41d078aaa9cf Paolo Bonzini 2021-10-21 727 /* ce41d078aaa9cf Paolo Bonzini 2021-10-21 728 * 0x80000021 is sometimes synthesized by __do_cpuid_func, which ce41d078aaa9cf Paolo Bonzini 2021-10-21 729 * would result in out-of-bounds calls to do_host_cpuid. ce41d078aaa9cf Paolo Bonzini 2021-10-21 730 */ ce41d078aaa9cf Paolo Bonzini 2021-10-21 731 { ce41d078aaa9cf Paolo Bonzini 2021-10-21 732 static int max_cpuid_80000000; ce41d078aaa9cf Paolo Bonzini 2021-10-21 733 if (!READ_ONCE(max_cpuid_80000000)) ce41d078aaa9cf Paolo Bonzini 2021-10-21 734 WRITE_ONCE(max_cpuid_80000000, cpuid_eax(0x80000000)); ce41d078aaa9cf Paolo Bonzini 2021-10-21 735 if (function > READ_ONCE(max_cpuid_80000000)) ce41d078aaa9cf Paolo Bonzini 2021-10-21 736 return entry; ce41d078aaa9cf Paolo Bonzini 2021-10-21 737 } ce41d078aaa9cf Paolo Bonzini 2021-10-21 738 2746a6b72ab9a9 Paolo Bonzini 2021-10-28 @739 default: 2746a6b72ab9a9 Paolo Bonzini 2021-10-28 740 break; 2746a6b72ab9a9 Paolo Bonzini 2021-10-28 741 } ab8bcf64971180 Paolo Bonzini 2019-06-24 742 00b27a3efb1160 Avi Kivity 2011-11-23 743 cpuid_count(entry->function, entry->index, 00b27a3efb1160 Avi Kivity 2011-11-23 744 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); d9aadaf689928b Paolo Bonzini 2019-07-04 745 d9aadaf689928b Paolo Bonzini 2019-07-04 746 switch (function) { d9aadaf689928b Paolo Bonzini 2019-07-04 747 case 4: d9aadaf689928b Paolo Bonzini 2019-07-04 748 case 7: d9aadaf689928b Paolo Bonzini 2019-07-04 749 case 0xb: d9aadaf689928b Paolo Bonzini 2019-07-04 750 case 0xd: a06dcd625d6181 Jim Mattson 2019-09-12 751 case 0xf: a06dcd625d6181 Jim Mattson 2019-09-12 752 case 0x10: a06dcd625d6181 Jim Mattson 2019-09-12 753 case 0x12: d9aadaf689928b Paolo Bonzini 2019-07-04 754 case 0x14: a06dcd625d6181 Jim Mattson 2019-09-12 755 case 0x17: a06dcd625d6181 Jim Mattson 2019-09-12 756 case 0x18: 690a757d610e50 Jing Liu 2022-01-05 757 case 0x1d: 690a757d610e50 Jing Liu 2022-01-05 758 case 0x1e: a06dcd625d6181 Jim Mattson 2019-09-12 759 case 0x1f: d9aadaf689928b Paolo Bonzini 2019-07-04 760 case 0x8000001d: d9aadaf689928b Paolo Bonzini 2019-07-04 761 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; d9aadaf689928b Paolo Bonzini 2019-07-04 762 break; d9aadaf689928b Paolo Bonzini 2019-07-04 763 } aa10a7dc8858f6 Sean Christopherson 2020-03-02 764 aa10a7dc8858f6 Sean Christopherson 2020-03-02 765 return entry; 00b27a3efb1160 Avi Kivity 2011-11-23 766 } 00b27a3efb1160 Avi Kivity 2011-11-23 767 :::::: The code at line 739 was first introduced by commit :::::: 2746a6b72ab9a92bd188c4ac3e4122ee1c18f754 KVM: x86: skip host CPUID call for hypervisor leaves :::::: TO: Paolo Bonzini <pbonzini@xxxxxxxxxx> :::::: CC: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
