Re: [PATCH 1/2] KVM: remove CONFIG_KVM_GENERIC_MMU_NOTIFIER

[kernel test robot <lkp@intel.com>]

Hi Paolo,

kernel test robot noticed the following build errors:

[auto build test ERROR on kvm/queue]
[also build test ERROR on kvm/next kvms390/next next-20260212]
[cannot apply to powerpc/topic/ppc-kvm kvmarm/next linus/master kvm/linux-next v6.16-rc1]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Paolo-Bonzini/KVM-remove-CONFIG_KVM_GENERIC_MMU_NOTIFIER/20260212-185546
base:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
patch link:    https://lore.kernel.org/r/20260212105211.1555876-2-pbonzini%40redhat.com
patch subject: [PATCH 1/2] KVM: remove CONFIG_KVM_GENERIC_MMU_NOTIFIER
config: x86_64-kexec (https://download.01.org/0day-ci/archive/20260212/202602121838.3VZCFFcb-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260212/202602121838.3VZCFFcb-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202602121838.3VZCFFcb-lkp@intel.com/

All errors (new ones prefixed by >>):

>> arch/x86/kvm/../../../virt/kvm/kvm_main.c:900:9: error: call to undeclared function 'mmu_notifier_register'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     900 |         return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
         |                ^
   arch/x86/kvm/../../../virt/kvm/kvm_main.c:900:9: note: did you mean 'mmu_notifier_release'?
   include/linux/mmu_notifier.h:598:20: note: 'mmu_notifier_release' declared here
     598 | static inline void mmu_notifier_release(struct mm_struct *mm)
         |                    ^
>> arch/x86/kvm/../../../virt/kvm/kvm_main.c:1220:3: error: call to undeclared function 'mmu_notifier_unregister'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1220 |                 mmu_notifier_unregister(&kvm->mmu_notifier, current->mm);
         |                 ^
   arch/x86/kvm/../../../virt/kvm/kvm_main.c:1220:3: note: did you mean 'preempt_notifier_unregister'?
   include/linux/preempt.h:357:6: note: 'preempt_notifier_unregister' declared here
     357 | void preempt_notifier_unregister(struct preempt_notifier *notifier);
         |      ^
   arch/x86/kvm/../../../virt/kvm/kvm_main.c:1283:2: error: call to undeclared function 'mmu_notifier_unregister'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1283 |         mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
         |         ^
   3 errors generated.


vim +/mmu_notifier_register +900 arch/x86/kvm/../../../virt/kvm/kvm_main.c

4c07b0a4b6df45 Avi Kivity 2009-12-20  896  
4c07b0a4b6df45 Avi Kivity 2009-12-20  897  static int kvm_init_mmu_notifier(struct kvm *kvm)
4c07b0a4b6df45 Avi Kivity 2009-12-20  898  {
4c07b0a4b6df45 Avi Kivity 2009-12-20  899  	kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
4c07b0a4b6df45 Avi Kivity 2009-12-20 @900  	return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
4c07b0a4b6df45 Avi Kivity 2009-12-20  901  }
4c07b0a4b6df45 Avi Kivity 2009-12-20  902  

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