Hi Marc,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   88bb507a74ea7d75fa49edd421eaa710a7d80598
commit: 1db9d9ded771389aae5760d20dd1bac113451b9c KVM: arm64: Add kimg_hyp_va() helper
date:   3 months ago
config: arm64-randconfig-r024-20210202 (attached as .config)
compiler: aarch64-linux-gcc (GCC) 9.3.0
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/?id=1db9d9ded771389aae5760d20dd1bac113451b9c
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 1db9d9ded771389aae5760d20dd1bac113451b9c
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   arch/arm64/kvm/va_layout.c:138:6: warning: no previous prototype for 'kvm_patch_vector_branch' [-Wmissing-prototypes]
     138 | void kvm_patch_vector_branch(struct alt_instr *alt,
         |      ^~~~~~~~~~~~~~~~~~~~~~~
>> arch/arm64/kvm/va_layout.c:249:6: warning: no previous prototype for 'kvm_update_kimg_phys_offset' [-Wmissing-prototypes]
     249 | void kvm_update_kimg_phys_offset(struct alt_instr *alt,
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/kvm_update_kimg_phys_offset +249 arch/arm64/kvm/va_layout.c

   248	
 > 249	void kvm_update_kimg_phys_offset(struct alt_instr *alt,

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org