tree: https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git sev-es-kexec head: 3467dc3cdbe65c619cd9b5c8db47da63b0655300 commit: f5fa86f9ca509214e22902fd1865e813d0d856b3 [9/12] x86/sev: Use AP Jump Table blob to stop CPU config: x86_64-randconfig-a004-20210702 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 9eb613b2de3163686b1a4bd1160f15ac56a4b083) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git/commit/?id=f5fa86f9ca509214e22902fd1865e813d0d856b3 git remote add joro https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git git fetch --no-tags joro sev-es-kexec git checkout f5fa86f9ca509214e22902fd1865e813d0d856b3 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): >> arch/x86/kernel/sev.c:698:17: warning: no previous prototype for function 'sev_jumptable_ap_park' [-Wmissing-prototypes] void __noreturn sev_jumptable_ap_park(void) ^ arch/x86/kernel/sev.c:698:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void __noreturn sev_jumptable_ap_park(void) ^ static arch/x86/kernel/sev.c:803:13: warning: no previous prototype for function 'sev_es_setup_ap_jump_table_data' [-Wmissing-prototypes] void __init sev_es_setup_ap_jump_table_data(void *base, u32 pa) ^ arch/x86/kernel/sev.c:803:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void __init sev_es_setup_ap_jump_table_data(void *base, u32 pa) ^ static 2 warnings generated. vim +/sev_jumptable_ap_park +698 arch/x86/kernel/sev.c 1aa9aa8ee517e0 arch/x86/kernel/sev-es.c Joerg Roedel 2020-09-08 697 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 @698 void __noreturn sev_jumptable_ap_park(void) 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 699 { 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 700 local_irq_disable(); 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 701 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 702 write_cr3(real_mode_header->trampoline_pgd); 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 703 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 704 /* Exiting long mode will fail if CR4.PCIDE is set. */ 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 705 if (boot_cpu_has(X86_FEATURE_PCID)) 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 706 cr4_clear_bits(X86_CR4_PCIDE); 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 707 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 708 asm volatile("xorq %%r15, %%r15\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 709 "xorq %%r14, %%r14\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 710 "xorq %%r13, %%r13\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 711 "xorq %%r12, %%r12\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 712 "xorq %%r11, %%r11\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 713 "xorq %%r10, %%r10\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 714 "xorq %%r9, %%r9\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 715 "xorq %%r8, %%r8\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 716 "xorq %%rsi, %%rsi\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 717 "xorq %%rdi, %%rdi\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 718 "xorq %%rsp, %%rsp\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 719 "xorq %%rbp, %%rbp\n" 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 720 "ljmpl *%0" : : 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 721 "m" (real_mode_header->sev_real_ap_park_asm), 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 722 "b" (sev_es_jump_table_pa >> 4)); 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 723 unreachable(); 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 724 } 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 725 STACK_FRAME_NON_STANDARD(sev_jumptable_ap_park); 700d0a170431bd arch/x86/kernel/sev.c Joerg Roedel 2021-06-24 726 :::::: The code at line 698 was first introduced by commit :::::: 700d0a170431bd18f1f3e1d10befe530bce97567 x86/sev: Park APs on AP Jump Table with GHCB protocol version 2 :::::: TO: Joerg Roedel :::::: CC: Joerg Roedel --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org