This is a note to let you know that I've just added the patch titled
KVM: x86/mmu: Don't redundantly clear TDP MMU pt memory
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-x86-mmu-don-t-redundantly-clear-tdp-mmu-pt-memor.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7ad0aa324fd19e916eae8be382c98efee1b759c6
Author: Ben Gardon <bgardon@xxxxxxxxxx>
Date: Tue Feb 2 10:57:10 2021 -0800
KVM: x86/mmu: Don't redundantly clear TDP MMU pt memory
[ Upstream commit 734e45b329d626d2c14e2bcf8be3d069a33c3316 ]
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@xxxxxxxxxx>
Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx>
Message-Id: <20210202185734.1680553-5-bgardon@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index f88404033e0c..136311be5890 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -706,7 +706,6 @@ 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);
