arm/arm64: KVM: Report correct FSC for unsupported fault types

When we catch something that's not a permission fault or a translation
fault, we log the unsupported FSC in the kernel log, but we were masking
off the bottom bits of the FSC which was not very helpful.

Also correctly report the FSC for data and instruction faults rather
than telling people it was a DFCS, which doesn't exist in the ARM ARM.
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

arch/arm/include/asm/kvm_emulate.h

@@ -148,6 +148,11 @@ static inline bool kvm_vcpu_trap_is_iabt(struct kvm_vcpu *vcpu)
 }
 
 static inline u8 kvm_vcpu_trap_get_fault(struct kvm_vcpu *vcpu)
+{
+	return kvm_vcpu_get_hsr(vcpu) & HSR_FSC;
+}
+
+static inline u8 kvm_vcpu_trap_get_fault_type(struct kvm_vcpu *vcpu)
 {
 	return kvm_vcpu_get_hsr(vcpu) & HSR_FSC_TYPE;
 }

arch/arm/kvm/mmu.c

@@ -882,10 +882,12 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
 			      kvm_vcpu_get_hfar(vcpu), fault_ipa);
 
 	/* Check the stage-2 fault is trans. fault or write fault */
-	fault_status = kvm_vcpu_trap_get_fault(vcpu);
+	fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
 	if (fault_status != FSC_FAULT && fault_status != FSC_PERM) {
-		kvm_err("Unsupported fault status: EC=%#x DFCS=%#lx\n",
-			kvm_vcpu_trap_get_class(vcpu), fault_status);
+		kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
+			kvm_vcpu_trap_get_class(vcpu),
+			(unsigned long)kvm_vcpu_trap_get_fault(vcpu),
+			(unsigned long)kvm_vcpu_get_hsr(vcpu));
 		return -EFAULT;
 	}
 

arch/arm64/include/asm/kvm_emulate.h

@@ -173,6 +173,11 @@ static inline bool kvm_vcpu_trap_is_iabt(const struct kvm_vcpu *vcpu)
 }
 
 static inline u8 kvm_vcpu_trap_get_fault(const struct kvm_vcpu *vcpu)
+{
+	return kvm_vcpu_get_hsr(vcpu) & ESR_EL2_FSC;
+}
+
+static inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vcpu)
 {
 	return kvm_vcpu_get_hsr(vcpu) & ESR_EL2_FSC_TYPE;
 }