KVM: Optimize kvm_mmu_unprotect_page_virt() for tdp

We know no pages are protected, so we can short-circuit the whole thing
(including fairly nasty guest memory accesses).

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 6f38178af926..eca41ae9f453 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2694,6 +2694,9 @@ int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
         gpa_t gpa;
         int r;
 
+        if (tdp_enabled)
+                return 0;
+
         gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
 
         spin_lock(&vcpu->kvm->mmu_lock);