ARM: KVM: abstract (and fix) external abort detection away

Bit 8 is cache maintenance, bit 9 is external abort.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <cdall@cs.columbia.edu>

arch/arm/include/asm/kvm_arm.h

@@ -211,4 +211,7 @@
 
 #define HSR_HVC_IMM_MASK	((1UL << 16) - 1)
 
+#define HSR_DABT_CM		(1U << 8)
+#define HSR_DABT_EA		(1U << 9)
+
 #endif /* __ARM_KVM_ARM_H__ */

arch/arm/include/asm/kvm_emulate.h

@@ -110,4 +110,9 @@ static inline int kvm_vcpu_dabt_get_rd(struct kvm_vcpu *vcpu)
 	return (kvm_vcpu_get_hsr(vcpu) & HSR_SRT_MASK) >> HSR_SRT_SHIFT;
 }
 
+static inline bool kvm_vcpu_dabt_isextabt(struct kvm_vcpu *vcpu)
+{
+	return kvm_vcpu_get_hsr(vcpu) & HSR_DABT_EA;
+}
+
 #endif /* __ARM_KVM_EMULATE_H__ */

arch/arm/kvm/mmio.c

@@ -65,7 +65,7 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	unsigned long rt, len;
 	bool is_write, sign_extend;
 
-	if ((kvm_vcpu_get_hsr(vcpu) >> 8) & 1) {
+	if (kvm_vcpu_dabt_isextabt(vcpu)) {
 		/* cache operation on I/O addr, tell guest unsupported */
 		kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
 		return 1;