Hi Jason, I love your patch! Perhaps something to improve: [auto build test WARNING on vhost/linux-next] [also build test WARNING on linus/master v5.9-rc1 next-20200821] [cannot apply to linux/master] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Jason-Wang/vDPA-API-for-reportin... base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next config: ia64-allmodconfig (attached as .config) compiler: ia64-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 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=ia64 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 >>): 577 | struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa) | ^~~~~~~~~~~~~~~~~~~~~~ # https://github.com/0day-ci/linux/commit/fba5ff6281e9d46144860bcc558068b55... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jason-Wang/vDPA-API-for-reporting-IOVA-range/20200821-173030 git checkout fba5ff6281e9d46144860bcc558068b5516e5e62 vim +/vdpasim_get_iova_range +577 drivers/vdpa/vdpa_sim/vdpa_sim.c 576 578 { 579 struct vdpa_iova_range range = { 580 .first = 0ULL, 581 .last = ULLONG_MAX, 582 }; 583 584 return range; 585 } 586 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org