Re: [PATCH -v3 1/2] KVM: introduce kvm_uninit_mmu_notifier()

[Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>]

I made this patch for the coalesced mmio's error handling work.

Though, I wanted to finish this work, I have no time this week any more.
I'll do the remaining part next week, sorry.


Takuya Yoshikawa wrote:
> We have kvm_init_mmu_notifier() for registering mmu notifier.
> This patch makes the counterpart for unregister.
> 
> Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
> ---
>  virt/kvm/kvm_main.c |   16 +++++++++++-----
>  1 files changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index e758ef7..64b792c 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -359,6 +359,11 @@ static int kvm_init_mmu_notifier(struct kvm *kvm)
>  	return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
>  }
>  
> +static void kvm_uninit_mmu_notifier(struct kvm *kvm)
> +{
> +	mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
> +}
> +
>  #else  /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
>  
>  static int kvm_init_mmu_notifier(struct kvm *kvm)
> @@ -366,6 +371,11 @@ static int kvm_init_mmu_notifier(struct kvm *kvm)
>  	return 0;
>  }
>  
> +static void kvm_uninit_mmu_notifier(struct kvm *kvm)
> +{
> +	kvm_arch_flush_shadow(kvm);
> +}
> +
>  #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
>  
>  static struct kvm *kvm_create_vm(void)
> @@ -485,11 +495,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
>  	for (i = 0; i < KVM_NR_BUSES; i++)
>  		kvm_io_bus_destroy(kvm->buses[i]);
>  	kvm_coalesced_mmio_free(kvm);
> -#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
> -	mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
> -#else
> -	kvm_arch_flush_shadow(kvm);
> -#endif
> +	kvm_uninit_mmu_notifier(kvm);
>  	kvm_arch_destroy_vm(kvm);
>  	hardware_disable_all();
>  	mmdrop(mm);