KVM: arm64: Refactor __populate_fault_info()

Refactor __populate_fault_info() to introduce __get_fault_info() which
will be used once the host is wrapped in a stage 2.
Acked-by: NWill Deacon <will@kernel.org>
Signed-off-by: NQuentin Perret <qperret@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-25-qperret@google.com

arch/arm64/kvm/hyp/include/hyp/switch.h

@@ -160,18 +160,10 @@ static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar)
 	return true;
 }
 
-static inline bool __populate_fault_info(struct kvm_vcpu *vcpu)
+static inline bool __get_fault_info(u64 esr, struct kvm_vcpu_fault_info *fault)
 {
-	u8 ec;
-	u64 esr;
 	u64 hpfar, far;
 
-	esr = vcpu->arch.fault.esr_el2;
-	ec = ESR_ELx_EC(esr);
-
-	if (ec != ESR_ELx_EC_DABT_LOW && ec != ESR_ELx_EC_IABT_LOW)
-		return true;
-
 	far = read_sysreg_el2(SYS_FAR);
 
 	/*
@@ -194,11 +186,25 @@ static inline bool __populate_fault_info(struct kvm_vcpu *vcpu)
 		hpfar = read_sysreg(hpfar_el2);
 	}
 
-	vcpu->arch.fault.far_el2 = far;
-	vcpu->arch.fault.hpfar_el2 = hpfar;
+	fault->far_el2 = far;
+	fault->hpfar_el2 = hpfar;
 	return true;
 }
 
+static inline bool __populate_fault_info(struct kvm_vcpu *vcpu)
+{
+	u8 ec;
+	u64 esr;
+
+	esr = vcpu->arch.fault.esr_el2;
+	ec = ESR_ELx_EC(esr);
+
+	if (ec != ESR_ELx_EC_DABT_LOW && ec != ESR_ELx_EC_IABT_LOW)
+		return true;
+
+	return __get_fault_info(esr, &vcpu->arch.fault);
+}
+
 static inline void __hyp_sve_save_host(struct kvm_vcpu *vcpu)
 {
 	struct thread_struct *thread;