From: Avi Kivity <avi@redhat.com>
Date: Thu, 27 Aug 2009 10:37:06 +0000 (+0300)
Subject: KVM: Optimize kvm_mmu_unprotect_page_virt() for tdp
X-Git-Tag: firefly_0821_release~12973^2~13
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=60f24784a92c25c269a5e741a8ce8ff63e887be8;p=firefly-linux-kernel-4.4.55.git

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>
---

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);