KVM: x86/mmu: Don't redundantly clear TDP MMU pt memory

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>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210202185734.1680553-5-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 05e6e2c..810de32 100644 (file)
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -655,7 +655,6 @@ 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);