KVM: arm/arm64: vgic: Check return value for kvm_register_vgic_device

kvm_register_device_ops() can return an error, so lets check its return
value and propagate this up the call chain.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

virt/kvm/arm/vgic/vgic-v2.c

@@ -332,20 +332,25 @@ int vgic_v2_probe(const struct gic_kvm_info *info)
 	vtr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VTR);
 	kvm_vgic_global_state.nr_lr = (vtr & 0x3f) + 1;
 
+	ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);
+	if (ret) {
+		kvm_err("Cannot register GICv2 KVM device\n");
+		iounmap(kvm_vgic_global_state.vctrl_base);
+		return ret;
+	}
+
 	ret = create_hyp_io_mappings(kvm_vgic_global_state.vctrl_base,
 				     kvm_vgic_global_state.vctrl_base +
 					 resource_size(&info->vctrl),
 				     info->vctrl.start);
-
 	if (ret) {
 		kvm_err("Cannot map VCTRL into hyp\n");
+		kvm_unregister_device_ops(KVM_DEV_TYPE_ARM_VGIC_V2);
 		iounmap(kvm_vgic_global_state.vctrl_base);
 		return ret;
 	}
 
 	kvm_vgic_global_state.can_emulate_gicv2 = true;
-	kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);
-
 	kvm_vgic_global_state.vcpu_base = info->vcpu.start;
 	kvm_vgic_global_state.type = VGIC_V2;
 	kvm_vgic_global_state.max_gic_vcpus = VGIC_V2_MAX_CPUS;