tree: https://github.com/intel/tdx.git tdx/guest-rebased head: e3995864d37c56f431c93fc3dc454d9c65f5e9ea commit: 756e9ea1c2ce5a460d5e3edc980255eea5f0fecf [108/133] x86/tdx: Enable direct iomap MMIO optimizations config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20220114/202201140431.dg81It8G-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/intel/tdx/commit/756e9ea1c2ce5a460d5e3edc980255eea5f0fecf git remote add intel-tdx https://github.com/intel/tdx.git git fetch --no-tags intel-tdx tdx/guest-rebased git checkout 756e9ea1c2ce5a460d5e3edc980255eea5f0fecf # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/kernel/ 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 >>): arch/x86/kernel/tdx.c:268:5: warning: no previous prototype for 'tdx_hcall_set_notify_intr' [-Wmissing-prototypes] 268 | int tdx_hcall_set_notify_intr(u8 vector) | ^~~~~~~~~~~~~~~~~~~~~~~~~ arch/x86/kernel/tdx.c:509:14: warning: no previous prototype for 'tdx_write_msr' [-Wmissing-prototypes] 509 | void notrace tdx_write_msr(unsigned int msr, u32 low, u32 high) | ^~~~~~~~~~~~~ 692 | unsigned long tdx_mmio_readq(void __iomem *addr) | ^~~~~~~~~~~~~~ vim +/tdx_mmio_readq +692 arch/x86/kernel/tdx.c 691 693 { 694 unsigned long val; 695 696 if (tdx_virt_mmio(8, false, (unsigned long)addr, &val)) 697 return 0xffffffffffffffff; 698 return val; 699 } 700 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org