Hi Hui,

[FYI, it's a private test report for your RFC patch.]
[auto build test ERROR on linus/master]
[also build test ERROR on v5.13-rc7 next-20210623]
[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/Hui-Zhu/virtio-mem-Add-support-of-memory_hotplug-memmap_on_memory/20210623-200242
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 0c18f29aae7ce3dadd26d8ee3505d07cc982df75
config: x86_64-randconfig-a001-20210622 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project b259740801d3515810ecc15bf0c24b0d476a1608)
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
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/7c3e5b6a98dff36b10e34c1b20773850c587e2b2
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Hui-Zhu/virtio-mem-Add-support-of-memory_hotplug-memmap_on_memory/20210623-200242
        git checkout 7c3e5b6a98dff36b10e34c1b20773850c587e2b2
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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: "mhp_supports_memmap_on_memory" [drivers/virtio/virtio_mem.ko] undefined!

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