Hi Jason,

I love your patch! Yet something to improve:

[auto build test ERROR on vhost/linux-next]
[also build test ERROR on linux/master linus/master v5.5-rc6 next-20200117]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Jason-Wang/vDPA-support/20200117-170243
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
config: i386-randconfig-g003-20200117 (attached as .config)
compiler: gcc-7 (Debian 7.5.0-3) 7.5.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

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

All errors (new ones prefixed by >>):

   ld: drivers/vhost/vhost.o: in function `vhost_dev_reset_owner_prepare':
>> (.text+0x18b): undefined reference to `vhost_iotlb_alloc'
   ld: drivers/vhost/vhost.o: in function `vhost_init_device_iotlb':
   (.text+0x204): undefined reference to `vhost_iotlb_alloc'
>> ld: (.text+0x26c): undefined reference to `vhost_iotlb_free'
   ld: drivers/vhost/vhost.o: in function `iotlb_access_ok':
>> vhost.c:(.text+0x60e): undefined reference to `vhost_iotlb_itree_first'
   ld: drivers/vhost/vhost.o: in function `translate_desc':
   vhost.c:(.text+0x85f): undefined reference to `vhost_iotlb_itree_first'
   ld: drivers/vhost/vhost.o: in function `vhost_dev_cleanup':
>> (.text+0xd4a): undefined reference to `vhost_iotlb_free'
   ld: (.text+0xd59): undefined reference to `vhost_iotlb_free'
   ld: drivers/vhost/vhost.o: in function `vhost_chr_write_iter':
>> (.text+0x1c3b): undefined reference to `vhost_iotlb_del_range'
>> ld: (.text+0x1d78): undefined reference to `vhost_iotlb_add_range'
   ld: drivers/vhost/vhost.o: in function `vhost_dev_ioctl':
   (.text+0x3d6d): undefined reference to `vhost_iotlb_alloc'
   ld: (.text+0x3dd5): undefined reference to `vhost_iotlb_add_range'
   ld: (.text+0x3de4): undefined reference to `vhost_iotlb_free'
   ld: (.text+0x3e7e): undefined reference to `vhost_iotlb_free'

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0-DAY kernel test infrastructure                 Open Source Technology Center
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation