static u64 kvm_dr6_fixed(struct kvm_vcpu *vcpu)
{
	u64 fixed = DR6_FIXED_1;

	if (!guest_cpuid_has_rtm(vcpu))
		fixed |= DR6_RTM;
	return fixed;
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.