[PATCH v2 05/17] kvm: x86: Introduce KVM_REQ_LOAD_CR3

[Junaid Shahid <junaids@xxxxxxxxxx>]

The KVM_REQ_LOAD_CR3 request loads the hardware CR3 using the
current root_hpa.

Signed-off-by: Junaid Shahid <junaids@xxxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/mmu.c              | 3 +--
 arch/x86/kvm/mmu.h              | 7 +++++++
 arch/x86/kvm/x86.c              | 2 ++
 4 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 0869a684f852..42a6b5616ce2 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -54,6 +54,7 @@
 #define KVM_REQ_TRIPLE_FAULT		KVM_ARCH_REQ(2)
 #define KVM_REQ_MMU_SYNC		KVM_ARCH_REQ(3)
 #define KVM_REQ_CLOCK_UPDATE		KVM_ARCH_REQ(4)
+#define KVM_REQ_LOAD_CR3		KVM_ARCH_REQ(5)
 #define KVM_REQ_EVENT			KVM_ARCH_REQ(6)
 #define KVM_REQ_APF_HALT		KVM_ARCH_REQ(7)
 #define KVM_REQ_STEAL_UPDATE		KVM_ARCH_REQ(8)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5dde85c4f65a..8fddcb456a44 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4842,8 +4842,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
 	kvm_mmu_sync_roots(vcpu);
 	if (r)
 		goto out;
-	/* set_cr3() should ensure TLB has been flushed */
-	vcpu->arch.mmu.set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
+	kvm_mmu_load_cr3(vcpu);
 out:
 	return r;
 }
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index ef6763b9d9b6..605cce1246c4 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -96,6 +96,13 @@ static inline int kvm_mmu_reload(struct kvm_vcpu *vcpu)
 	return kvm_mmu_load(vcpu);
 }
 
+static inline void kvm_mmu_load_cr3(struct kvm_vcpu *vcpu)
+{
+	/* set_cr3() should ensure TLB has been flushed */
+	if (VALID_PAGE(vcpu->arch.mmu.root_hpa))
+		vcpu->arch.mmu.set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
+}
+
 /*
  * Currently, we have two sorts of write-protection, a) the first one
  * write-protects guest page to sync the guest modification, b) another one is
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2d1041b5739b..239c814c07c3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7280,6 +7280,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 		}
 		if (kvm_check_request(KVM_REQ_MMU_SYNC, vcpu))
 			kvm_mmu_sync_roots(vcpu);
+		if (kvm_check_request(KVM_REQ_LOAD_CR3, vcpu))
+			kvm_mmu_load_cr3(vcpu);
 		if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu))
 			kvm_vcpu_flush_tlb(vcpu, true);
 		if (kvm_check_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu)) {
-- 
2.18.0.rc1.242.g61856ae69a-goog