KVM: arm64: vgic-its: Introduce config option to guard ITS specific code

By now ITS code guarded with KVM_ARM_VGIC_V3 config option which was
introduced to hide everything specific to vgic-v3 from 32-bit world.
We are going to support vgic-v3 in 32-bit world and KVM_ARM_VGIC_V3
will gone, but we don't have support for ITS there yet and we need to
continue keeping ITS away.
Introduce the new config option to prevent ITS code being build in
32-bit mode when support for vgic-v3 is done.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

virt/kvm/arm/vgic/vgic-kvm-device.c

@@ -223,9 +223,12 @@ int kvm_register_vgic_device(unsigned long type)
 	case KVM_DEV_TYPE_ARM_VGIC_V3:
 		ret = kvm_register_device_ops(&kvm_arm_vgic_v3_ops,
 					      KVM_DEV_TYPE_ARM_VGIC_V3);
+
+#ifdef CONFIG_KVM_ARM_VGIC_V3_ITS
 		if (ret)
 			break;
 		ret = kvm_vgic_register_its_device();
+#endif
 		break;
 #endif
 	}

virt/kvm/arm/vgic/vgic-mmio-v3.c

@@ -42,6 +42,7 @@ u64 update_64bit_reg(u64 reg, unsigned int offset, unsigned int len,
 	return reg | ((u64)val << lower);
 }
 
+#ifdef CONFIG_KVM_ARM_VGIC_V3_ITS
 bool vgic_has_its(struct kvm *kvm)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
@@ -51,6 +52,7 @@ bool vgic_has_its(struct kvm *kvm)
 
 	return dist->has_its;
 }
+#endif
 
 static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
 					    gpa_t addr, unsigned int len)

virt/kvm/arm/vgic/vgic.h

@@ -84,11 +84,15 @@ void vgic_v3_enable(struct kvm_vcpu *vcpu);
 int vgic_v3_probe(const struct gic_kvm_info *info);
 int vgic_v3_map_resources(struct kvm *kvm);
 int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t dist_base_address);
+
+#ifdef CONFIG_KVM_ARM_VGIC_V3_ITS
 int vgic_register_its_iodevs(struct kvm *kvm);
 bool vgic_has_its(struct kvm *kvm);
 int kvm_vgic_register_its_device(void);
 void vgic_enable_lpis(struct kvm_vcpu *vcpu);
 int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi);
+#endif
+
 #else
 static inline void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu)
 {