Hi Jason, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 42eb8fdac2fc5d62392dcfcf0253753e821a97b0 commit: 34aff14580d1b02971adfd63be994f9c045919aa xen: Remove Xen PVH/PVHVM dependency on PCI date: 11 months ago config: i386-buildonly-randconfig-r005-20211118 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c46becf500df2a7fb4b4fce16178a036c344315a) 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/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 34aff14580d1b02971adfd63be994f9c045919aa # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=i386 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 >>): void __init xen_pvh_init(struct boot_params *boot_params) ^ arch/x86/xen/enlighten_pvh.c:26:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void __init xen_pvh_init(struct boot_params *boot_params) ^ static void __init mem_map_via_hcall(struct boot_params *boot_params_p) ^ arch/x86/xen/enlighten_pvh.c:42:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void __init mem_map_via_hcall(struct boot_params *boot_params_p) ^ static 2 warnings generated. vim +/xen_pvh_init +26 arch/x86/xen/enlighten_pvh.c 8cee3974b35bfb Maran Wilson 2018-12-10 25 72813bfbf0276a Roger Pau Monne 2019-04-23 @26 void __init xen_pvh_init(struct boot_params *boot_params) 8cee3974b35bfb Maran Wilson 2018-12-10 27 { 8cee3974b35bfb Maran Wilson 2018-12-10 28 u32 msr; 8cee3974b35bfb Maran Wilson 2018-12-10 29 u64 pfn; 8cee3974b35bfb Maran Wilson 2018-12-10 30 8cee3974b35bfb Maran Wilson 2018-12-10 31 xen_pvh = 1; c9f804d64bb93c Roger Pau Monne 2019-04-23 32 xen_domain_type = XEN_HVM_DOMAIN; 8cee3974b35bfb Maran Wilson 2018-12-10 33 xen_start_flags = pvh_start_info.flags; 8cee3974b35bfb Maran Wilson 2018-12-10 34 8cee3974b35bfb Maran Wilson 2018-12-10 35 msr = cpuid_ebx(xen_cpuid_base() + 2); 8cee3974b35bfb Maran Wilson 2018-12-10 36 pfn = __pa(hypercall_page); 8cee3974b35bfb Maran Wilson 2018-12-10 37 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32)); 72813bfbf0276a Roger Pau Monne 2019-04-23 38 72813bfbf0276a Roger Pau Monne 2019-04-23 39 xen_efi_init(boot_params); 8cee3974b35bfb Maran Wilson 2018-12-10 40 } a43fb7da53007e Maran Wilson 2018-12-10 41 a43fb7da53007e Maran Wilson 2018-12-10 @42 void __init mem_map_via_hcall(struct boot_params *boot_params_p) :::::: The code at line 26 was first introduced by commit :::::: 72813bfbf0276a97c82af038efb5f02dcdd9e310 xen/pvh: correctly setup the PV EFI interface for dom0 :::::: TO: Roger Pau Monne <roger.pau(a)citrix.com&gt; :::::: CC: Boris Ostrovsky <boris.ostrovsky(a)oracle.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org