int kvm_vgic_hyp_init()

in kvm/vgic/vgic-init.c [522:597]

• 59 lines of code
• 12 McCabe index (conditional complexity)

int kvm_vgic_hyp_init(void)
{
	bool has_mask;
	int ret;

	if (!gic_kvm_info)
		return -ENODEV;

	has_mask = !gic_kvm_info->no_maint_irq_mask;

	if (has_mask && !gic_kvm_info->maint_irq) {
		kvm_err("No vgic maintenance irq\n");
		return -ENXIO;
	}

	/*
	 * If we get one of these oddball non-GICs, taint the kernel,
	 * as we have no idea of how they *really* behave.
	 */
	if (gic_kvm_info->no_hw_deactivation) {
		kvm_info("Non-architectural vgic, tainting kernel\n");
		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
		kvm_vgic_global_state.no_hw_deactivation = true;
	}

	switch (gic_kvm_info->type) {
	case GIC_V2:
		ret = vgic_v2_probe(gic_kvm_info);
		break;
	case GIC_V3:
		ret = vgic_v3_probe(gic_kvm_info);
		if (!ret) {
			static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
			kvm_info("GIC system register CPU interface enabled\n");
		}
		break;
	default:
		ret = -ENODEV;
	}

	kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;

	kfree(gic_kvm_info);
	gic_kvm_info = NULL;

	if (ret)
		return ret;

	if (!has_mask)
		return 0;

	ret = request_percpu_irq(kvm_vgic_global_state.maint_irq,
				 vgic_maintenance_handler,
				 "vgic", kvm_get_running_vcpus());
	if (ret) {
		kvm_err("Cannot register interrupt %d\n",
			kvm_vgic_global_state.maint_irq);
		return ret;
	}

	ret = cpuhp_setup_state(CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
				"kvm/arm/vgic:starting",
				vgic_init_cpu_starting, vgic_init_cpu_dying);
	if (ret) {
		kvm_err("Cannot register vgic CPU notifier\n");
		goto out_free_irq;
	}

	kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
	return 0;

out_free_irq:
	free_percpu_irq(kvm_vgic_global_state.maint_irq,
			kvm_get_running_vcpus());
	return ret;
}