static int kvm_psci_0_2_call()

in kvm/psci.c [225:306]

• 56 lines of code
• 13 McCabe index (conditional complexity)

static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
{
	struct kvm *kvm = vcpu->kvm;
	u32 psci_fn = smccc_get_function(vcpu);
	unsigned long val;
	int ret = 1;

	val = kvm_psci_check_allowed_function(vcpu, psci_fn);
	if (val)
		goto out;

	switch (psci_fn) {
	case PSCI_0_2_FN_PSCI_VERSION:
		/*
		 * Bits[31:16] = Major Version = 0
		 * Bits[15:0] = Minor Version = 2
		 */
		val = KVM_ARM_PSCI_0_2;
		break;
	case PSCI_0_2_FN_CPU_SUSPEND:
	case PSCI_0_2_FN64_CPU_SUSPEND:
		val = kvm_psci_vcpu_suspend(vcpu);
		break;
	case PSCI_0_2_FN_CPU_OFF:
		kvm_psci_vcpu_off(vcpu);
		val = PSCI_RET_SUCCESS;
		break;
	case PSCI_0_2_FN_CPU_ON:
		kvm_psci_narrow_to_32bit(vcpu);
		fallthrough;
	case PSCI_0_2_FN64_CPU_ON:
		mutex_lock(&kvm->lock);
		val = kvm_psci_vcpu_on(vcpu);
		mutex_unlock(&kvm->lock);
		break;
	case PSCI_0_2_FN_AFFINITY_INFO:
		kvm_psci_narrow_to_32bit(vcpu);
		fallthrough;
	case PSCI_0_2_FN64_AFFINITY_INFO:
		val = kvm_psci_vcpu_affinity_info(vcpu);
		break;
	case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
		/*
		 * Trusted OS is MP hence does not require migration
	         * or
		 * Trusted OS is not present
		 */
		val = PSCI_0_2_TOS_MP;
		break;
	case PSCI_0_2_FN_SYSTEM_OFF:
		kvm_psci_system_off(vcpu);
		/*
		 * We shouldn't be going back to guest VCPU after
		 * receiving SYSTEM_OFF request.
		 *
		 * If user space accidentally/deliberately resumes
		 * guest VCPU after SYSTEM_OFF request then guest
		 * VCPU should see internal failure from PSCI return
		 * value. To achieve this, we preload r0 (or x0) with
		 * PSCI return value INTERNAL_FAILURE.
		 */
		val = PSCI_RET_INTERNAL_FAILURE;
		ret = 0;
		break;
	case PSCI_0_2_FN_SYSTEM_RESET:
		kvm_psci_system_reset(vcpu);
		/*
		 * Same reason as SYSTEM_OFF for preloading r0 (or x0)
		 * with PSCI return value INTERNAL_FAILURE.
		 */
		val = PSCI_RET_INTERNAL_FAILURE;
		ret = 0;
		break;
	default:
		val = PSCI_RET_NOT_SUPPORTED;
		break;
	}

out:
	smccc_set_retval(vcpu, val, 0, 0, 0);
	return ret;
}