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authorBen Gardon <bgardon@google.com>2021-02-02 10:57:21 -0800
committerPaolo Bonzini <pbonzini@redhat.com>2021-02-04 05:27:41 -0500
commit0f99ee2c7a58fc281c084d3acc0f0013bec7ec5a (patch)
tree6100d8999ff841beb77ef0235c010e0c01528ba0
parent1af4a96025b33587ca953c7ef12a1b20c6e70412 (diff)
downloadpowerpc-0f99ee2c7a58fc281c084d3acc0f0013bec7ec5a.tar.gz
KVM: x86/mmu: Skip no-op changes in TDP MMU functions
Skip setting SPTEs if no change is expected. Reviewed-by: Peter Feiner <pfeiner@google.com> Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20210202185734.1680553-16-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/mmu/tdp_mmu.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index c8a1149cb229de..aeb05f626b556b 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -888,7 +888,8 @@ static bool wrprot_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
continue;
if (!is_shadow_present_pte(iter.old_spte) ||
- !is_last_spte(iter.old_spte, iter.level))
+ !is_last_spte(iter.old_spte, iter.level) ||
+ !(iter.old_spte & PT_WRITABLE_MASK))
continue;
new_spte = iter.old_spte & ~PT_WRITABLE_MASK;
@@ -1065,7 +1066,8 @@ static bool set_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
if (tdp_mmu_iter_cond_resched(kvm, &iter, false))
continue;
- if (!is_shadow_present_pte(iter.old_spte))
+ if (!is_shadow_present_pte(iter.old_spte) ||
+ iter.old_spte & shadow_dirty_mask)
continue;
new_spte = iter.old_spte | shadow_dirty_mask;