Re: [PATCH] KVM: Remove unnecessary export of kvm_{inc,dec}_notifier_count()

From: Maxim Levitsky
Date: Sun Sep 05 2021 - 03:13:21 EST


On Thu, 2021-09-02 at 10:59 -0700, Sean Christopherson wrote:
> Don't export KVM's MMU notifier count helpers, under no circumstance
> should any downstream module, including x86's vendor code, have a
> legitimate reason to piggyback KVM's MMU notifier logic. E.g in the x86
> case, only KVM's MMU should be elevating the notifier count, and that
> code is always built into the core kvm.ko module.
>
> Fixes: edb298c663fc ("KVM: x86/mmu: bump mmu notifier count in kvm_zap_gfn_range")
> Cc: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> virt/kvm/kvm_main.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 3e67c93ca403..140c7d311021 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -638,7 +638,6 @@ void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start,
> max(kvm->mmu_notifier_range_end, end);
> }
> }
> -EXPORT_SYMBOL_GPL(kvm_inc_notifier_count);
>
> static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
> const struct mmu_notifier_range *range)
> @@ -690,8 +689,6 @@ void kvm_dec_notifier_count(struct kvm *kvm, unsigned long start,
> */
> kvm->mmu_notifier_count--;
> }
> -EXPORT_SYMBOL_GPL(kvm_dec_notifier_count);
> -
>
> static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
> const struct mmu_notifier_range *range)

Ah, I somehow thought when I wrote this that those two will be used by kvm_amd.

Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>

Best regards,
Maxim Levitsky