KVM: x86/mmu: Refactor is_tdp_mmu_root into is_tdp_mmu

This change simplifies the call sites slightly and also abstracts away
the implementation detail of looking at root_hpa as the mechanism for
determining if the mmu is the TDP MMU.
Suggested-by: NSean Christopherson <seanjc@google.com>
Signed-off-by: NDavid Matlack <dmatlack@google.com>
Message-Id: <20210617231948.2591431-4-dmatlack@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/mmu.c

@@ -3608,7 +3608,7 @@ static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep)
 		return reserved;
 	}
 
-	if (is_tdp_mmu_root(vcpu->arch.mmu->root_hpa))
+	if (is_tdp_mmu(vcpu->arch.mmu))
 		leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes, &root);
 	else
 		leaf = get_walk(vcpu, addr, sptes, &root);
@@ -3780,7 +3780,7 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
 static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 			     bool prefault, int max_level, bool is_tdp)
 {
-	bool is_tdp_mmu_fault = is_tdp_mmu_root(vcpu->arch.mmu->root_hpa);
+	bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu);
 	bool write = error_code & PFERR_WRITE_MASK;
 	bool map_writable;
 

arch/x86/kvm/mmu/tdp_mmu.h

@@ -86,9 +86,10 @@ void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm);
 static inline bool is_tdp_mmu_enabled(struct kvm *kvm) { return kvm->arch.tdp_mmu_enabled; }
 static inline bool is_tdp_mmu_page(struct kvm_mmu_page *sp) { return sp->tdp_mmu_page; }
 
-static inline bool is_tdp_mmu_root(hpa_t hpa)
+static inline bool is_tdp_mmu(struct kvm_mmu *mmu)
 {
 	struct kvm_mmu_page *sp;
+	hpa_t hpa = mmu->root_hpa;
 
 	if (WARN_ON(!VALID_PAGE(hpa)))
 		return false;
@@ -104,7 +105,7 @@ static inline bool kvm_mmu_init_tdp_mmu(struct kvm *kvm) { return false; }
 static inline void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm) {}
 static inline bool is_tdp_mmu_enabled(struct kvm *kvm) { return false; }
 static inline bool is_tdp_mmu_page(struct kvm_mmu_page *sp) { return false; }
-static inline bool is_tdp_mmu_root(hpa_t hpa) { return false; }
+static inline bool is_tdp_mmu(struct kvm_mmu *mmu) { return false; }
 #endif
 
 #endif /* __KVM_X86_MMU_TDP_MMU_H */