[PATCH v4 07/11] KVM: x86/mmu: Pivot on "TDP MMU enabled" when handling direct page faults

[Sean Christopherson]

When handling direct page faults, pivot on the TDP MMU being globally
enabled instead of checking if the target MMU is a TDP MMU.  Now that the
TDP MMU is all-or-nothing, if the TDP MMU is enabled, KVM will reach
direct_page_fault() if and only if the MMU is a TDP MMU.  When TDP is
enabled (obviously required for the TDP MMU), only non-nested TDP page
faults reach direct_page_fault(), i.e. nonpaging MMUs are impossible, as
NPT requires paging to be enabled and EPT faults use ept_page_fault().

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
 arch/x86/kvm/mmu/mmu.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 5710be4d328b..fe3aa890a487 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3324,7 +3324,7 @@ static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 	do {
 		u64 new_spte;
 
-		if (is_tdp_mmu(vcpu->arch.mmu))
+		if (is_tdp_mmu_enabled())
 			sptep = kvm_tdp_mmu_fast_pf_get_last_sptep(vcpu, fault->addr, &spte);
 		else
 			sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte);
@@ -4252,7 +4252,6 @@ static bool is_page_fault_stale(struct kvm_vcpu *vcpu,
 
 static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 {
-	bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu);
 	int r;
 
 	fault->gfn = fault->addr >> PAGE_SHIFT;
@@ -4275,7 +4274,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 
 	r = RET_PF_RETRY;
 
-	if (is_tdp_mmu_fault)
+	if (is_tdp_mmu_enabled())
 		read_lock(&vcpu->kvm->mmu_lock);
 	else
 		write_lock(&vcpu->kvm->mmu_lock);
@@ -4287,13 +4286,13 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	if (r)
 		goto out_unlock;
 
-	if (is_tdp_mmu_fault)
+	if (is_tdp_mmu_enabled())
 		r = kvm_tdp_mmu_map(vcpu, fault);
 	else
 		r = __direct_map(vcpu, fault);
 
 out_unlock:
-	if (is_tdp_mmu_fault)
+	if (is_tdp_mmu_enabled())
 		read_unlock(&vcpu->kvm->mmu_lock);
 	else
 		write_unlock(&vcpu->kvm->mmu_lock);
-- 
2.38.0.rc1.362.ged0d419d3c-goog