Re: [PATCH 09/24] kvm: x86/mmu: Don't redundantly clear TDP MMU pt memory

Paolo Bonzini
2021-01-26T14:17:14Z

On 12/01/21 19:10, Ben Gardon wrote:
> The KVM MMU caches already guarantee that shadow page table memory will
> be zeroed, so there is no reason to re-zero the page in the TDP MMU page
> fault handler.
>
> No functional change intended.
>
> Reviewed-by: Peter Feiner <pfeiner@google.com>
>
> Signed-off-by: Ben Gardon <bgardon@google.com>
> ---
> arch/x86/kvm/mmu/tdp_mmu.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
> index 411938e97a00..55df596696c7 100644
> --- a/arch/x86/kvm/mmu/tdp_mmu.c
> +++ b/arch/x86/kvm/mmu/tdp_mmu.c
> @@ -665,7 +665,6 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
> sp = alloc_tdp_mmu_page(vcpu, iter.gfn, iter.level);
> list_add(&sp->link, &vcpu->kvm->arch.tdp_mmu_pages);
> child_pt = sp->spt;
> - clear_page(child_pt);
> new_spte = make_nonleaf_spte(child_pt,
> !shadow_accessed_mask);
>
>

Queued, thanks.

Paolo