Hi Liu,

[FYI, it's a private test report for your RFC patch.]
[auto build test ERROR on hch-configfs/for-next]
[cannot apply to joro-iommu/next awilliam-vfio/next linus/master v5.15-rc1 next-20210917]
[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/Liu-Yi-L/Introduce-dev-iommu-for-userspace-I-O-address-space-management/20210919-144631
base:   git://git.infradead.org/users/hch/configfs.git for-next
config: mips-allmodconfig (attached as .config)
compiler: mips-linux-gcc (GCC) 11.2.0
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://github.com/0day-ci/linux/commit/89ec01e705473b8e3b52112ef19dc2e5f4b1c3cc
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Liu-Yi-L/Introduce-dev-iommu-for-userspace-I-O-address-space-management/20210919-144631
        git checkout 89ec01e705473b8e3b52112ef19dc2e5f4b1c3cc
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=mips 

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

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "vfio_device_add_iova_cap" [drivers/iommu/iommufd/iommufd.ko] undefined!

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