[PATCH 27/27] arm/arm64: KVM: Report correct FSC for unsupported fault types

[Christoffer Dall]

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: Peter Maydell <peter.maydell at linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
---
 arch/arm/include/asm/kvm_emulate.h   | 5 +++++
 arch/arm/kvm/mmu.c                   | 8 +++++---
 arch/arm64/include/asm/kvm_emulate.h | 5 +++++
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
index 69b7469..b9db269 100644
--- a/arch/arm/include/asm/kvm_emulate.h
+++ b/arch/arm/include/asm/kvm_emulate.h
@@ -149,6 +149,11 @@ 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;
 }
 
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index bb06f76..eea0306 100644
--- a/arch/arm/kvm/mmu.c
+++ b/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;
 	}
 
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index fdc3e21..5674a55 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -174,6 +174,11 @@ 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;
 }
 
-- 
2.0.0