Hi Peter,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on kvm/linux-next]
[also build test ERROR on next-20200110]
[cannot apply to kvmarm/next vfio/next v5.5-rc5]
[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/Peter-Xu/KVM-Dirty-ring-interface/20200110-152053
base:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git linux-next
config: s390-alldefconfig (attached as .config)
compiler: s390-linux-gcc (GCC) 7.5.0
reproduce:
        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
        GCC_VERSION=7.5.0 make.cross ARCH=s390 

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

All errors (new ones prefixed by >>):

   arch/s390/../../virt/kvm/kvm_main.o: In function `mark_page_dirty_in_slot':
>> kvm_main.c:(.text+0x4d6): undefined reference to `kvm_dirty_ring_get'
>> kvm_main.c:(.text+0x4f0): undefined reference to `kvm_dirty_ring_push'
   arch/s390/../../virt/kvm/kvm_main.o: In function `kvm_vcpu_init':
>> kvm_main.c:(.text+0x1fe6): undefined reference to `kvm_dirty_ring_alloc'
>> kvm_main.c:(.text+0x204c): undefined reference to `kvm_dirty_ring_free'
   arch/s390/../../virt/kvm/kvm_main.o: In function `kvm_vcpu_uninit':
   kvm_main.c:(.text+0x20c0): undefined reference to `kvm_dirty_ring_free'
   arch/s390/../../virt/kvm/kvm_main.o: In function `kvm_reset_dirty_gfn':
>> kvm_main.c:(.text+0x6650): undefined reference to `kvm_arch_mmu_enable_log_dirty_pt_masked'
   arch/s390/../../virt/kvm/kvm_main.o: In function `kvm_vm_ioctl':
>> kvm_main.c:(.text+0x6b58): undefined reference to `kvm_dirty_ring_reset'

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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