int kvm_reset_vcpu()

in kvm/reset.c [225:323]

• 74 lines of code
• 17 McCabe index (conditional complexity)

int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
{
	struct vcpu_reset_state reset_state;
	int ret;
	bool loaded;
	u32 pstate;

	mutex_lock(&vcpu->kvm->lock);
	reset_state = vcpu->arch.reset_state;
	WRITE_ONCE(vcpu->arch.reset_state.reset, false);
	mutex_unlock(&vcpu->kvm->lock);

	/* Reset PMU outside of the non-preemptible section */
	kvm_pmu_vcpu_reset(vcpu);

	preempt_disable();
	loaded = (vcpu->cpu != -1);
	if (loaded)
		kvm_arch_vcpu_put(vcpu);

	if (!kvm_arm_vcpu_sve_finalized(vcpu)) {
		if (test_bit(KVM_ARM_VCPU_SVE, vcpu->arch.features)) {
			ret = kvm_vcpu_enable_sve(vcpu);
			if (ret)
				goto out;
		}
	} else {
		kvm_vcpu_reset_sve(vcpu);
	}

	if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) ||
	    test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) {
		if (kvm_vcpu_enable_ptrauth(vcpu)) {
			ret = -EINVAL;
			goto out;
		}
	}

	if (!vcpu_allowed_register_width(vcpu)) {
		ret = -EINVAL;
		goto out;
	}

	switch (vcpu->arch.target) {
	default:
		if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
			pstate = VCPU_RESET_PSTATE_SVC;
		} else {
			pstate = VCPU_RESET_PSTATE_EL1;
		}

		if (kvm_vcpu_has_pmu(vcpu) && !kvm_arm_support_pmu_v3()) {
			ret = -EINVAL;
			goto out;
		}
		break;
	}

	/* Reset core registers */
	memset(vcpu_gp_regs(vcpu), 0, sizeof(*vcpu_gp_regs(vcpu)));
	memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs));
	vcpu->arch.ctxt.spsr_abt = 0;
	vcpu->arch.ctxt.spsr_und = 0;
	vcpu->arch.ctxt.spsr_irq = 0;
	vcpu->arch.ctxt.spsr_fiq = 0;
	vcpu_gp_regs(vcpu)->pstate = pstate;

	/* Reset system registers */
	kvm_reset_sys_regs(vcpu);

	/*
	 * Additional reset state handling that PSCI may have imposed on us.
	 * Must be done after all the sys_reg reset.
	 */
	if (reset_state.reset) {
		unsigned long target_pc = reset_state.pc;

		/* Gracefully handle Thumb2 entry point */
		if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
			target_pc &= ~1UL;
			vcpu_set_thumb(vcpu);
		}

		/* Propagate caller endianness */
		if (reset_state.be)
			kvm_vcpu_set_be(vcpu);

		*vcpu_pc(vcpu) = target_pc;
		vcpu_set_reg(vcpu, 0, reset_state.r0);
	}

	/* Reset timer */
	ret = kvm_timer_vcpu_reset(vcpu);
out:
	if (loaded)
		kvm_arch_vcpu_load(vcpu, smp_processor_id());
	preempt_enable();
	return ret;
}