tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: f1baf68e1383f6ed93eb9cff2866d46562607a43 commit: faff44069ff538ccdfef187c4d7ec83d22dfb3a4 x86/hyperv: Add Write/Read MSR registers via ghcb page date: 4 months ago config: x86_64-randconfig-s022 (https://download.01.org/0day-ci/archive/20220211/202202111322.CtsKURBj-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.4-dirty # 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 faff44069ff538ccdfef187c4d7ec83d22dfb3a4 # save the config file to linux build tree mkdir build_dir make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/hv/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) drivers/hv/vmbus_drv.c: note: in included file (through arch/x86/include/asm/msr.h, arch/x86/include/asm/processor.h, arch/x86/include/asm/timex.h, ...): arch/x86/include/asm/paravirt.h:221:9: sparse: sparse: cast truncates bits from constant value (c000000000000000 becomes 0) vim +221 arch/x86/include/asm/paravirt.h d3561b7fa0fb0fc include/asm-i386/paravirt.h Rusty Russell 2006-12-07 218 47edb65178cb705 arch/x86/include/asm/paravirt.h Andy Lutomirski 2015-07-23 219 static inline void wrmsrl(unsigned msr, u64 val) 47edb65178cb705 arch/x86/include/asm/paravirt.h Andy Lutomirski 2015-07-23 220 { 47edb65178cb705 arch/x86/include/asm/paravirt.h Andy Lutomirski 2015-07-23 @221 wrmsr(msr, (u32)val, (u32)(val>>32)); 47edb65178cb705 arch/x86/include/asm/paravirt.h Andy Lutomirski 2015-07-23 222 } 47edb65178cb705 arch/x86/include/asm/paravirt.h Andy Lutomirski 2015-07-23 223 :::::: The code at line 221 was first introduced by commit :::::: 47edb65178cb7056c2eea0b6c41a7d8c84547192 x86/asm/msr: Make wrmsrl() a function :::::: TO: Andy Lutomirski <luto(a)kernel.org&gt; :::::: CC: Ingo Molnar <mingo(a)kernel.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org