int kvm_arch_init_vm(struct kvm *kvm)
{
	INIT_LIST_HEAD(&kvm->arch.active_mmu_pages);
	INIT_LIST_HEAD(&kvm->arch.assigned_dev_head);

	/* Reserve bit 0 of irq_sources_bitmap for userspace irq source */
	set_bit(KVM_USERSPACE_IRQ_SOURCE_ID, &kvm->arch.irq_sources_bitmap);

	spin_lock_init(&kvm->arch.tsc_write_lock);

	return 0;
}

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.