Re: [PATCH v5 05/14] KVM: X86: Implement ring-based dirty memory tracking

[Peter Xu]

On Fri, Mar 06, 2020 at 07:32:20PM +0800, kbuild test robot wrote:
> Hi Peter,
> 
> Thank you for the patch! Yet something to improve:
> 
> [auto build test ERROR on tip/auto-latest]
> [also build test ERROR on linus/master v5.6-rc4]
> [cannot apply to kvm/linux-next linux/master vhost/linux-next next-20200305]
> [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/20200305-053531
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 6f2bc932d8ff72b1a0a5c66f3dad04ccba576a8b
> 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@xxxxxxxxx>
> 
> All errors (new ones prefixed by >>):
> 
>    arch/s390/../../virt/kvm/kvm_main.o: In function `kvm_reset_dirty_gfn':
> >> kvm_main.c:(.text+0x6a60): undefined reference to `kvm_arch_mmu_enable_log_dirty_pt_masked'

It turns out that when I wanted to fix the build error previously, I
did the compilation test (using a ppc64 host) without using the
correct config file, so KVM is not enabled at all...

I'll fix it (again) this time by moving kvm_reset_dirty_gfn() into
kvm_dirty_ring.c (and some other macro touch-ups).  I'll probably also
move KVM_DIRTY_LOG_PAGE_OFFSET==0 definition to uapi/linux/kvm.h.

Thanks,

-- 
Peter Xu