KVM: ARM: vgic: abstract MISR decoding

Instead of directly dealing with the GICH_MISR bits, move the code to
its own function and use a couple of public flags to represent the
actual state.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index ccb9b59..4857508 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -87,6 +87,7 @@
 	void	(*sync_lr_elrsr)(struct kvm_vcpu *, int, struct vgic_lr);
 	u64	(*get_elrsr)(const struct kvm_vcpu *vcpu);
 	u64	(*get_eisr)(const struct kvm_vcpu *vcpu);
+	u32	(*get_interrupt_status)(const struct kvm_vcpu *vcpu);
 };
 
 struct vgic_dist {
@@ -165,6 +166,9 @@
 
 #define LR_EMPTY	0xff
 
+#define INT_STATUS_EOI		(1 << 0)
+#define INT_STATUS_UNDERFLOW	(1 << 1)
+
 struct kvm;
 struct kvm_vcpu;
 struct kvm_run;