Consider these classical titles:
Commentarii de bello Gallico (Caesar)
Commentarii de bello civili (Caesar)
De inventione (Cicero)
De oratore ad Quintum fratrem libri tres (Cicero)
De re publica (Cicero)
Using the preposition de to denote the topic of a work is the typical choice in classical Latin.
The best option alongside de is to use an adjective: ...
The genitive is fine (carmen amoris, fabula amoris, etc.; I personally couldn't care less what anybody would like to call that genitive).
My own preference here would be with et or atque instead of -que: Carmen glaciei et/atque ignis.
The option with de is not wrong (carmen de bello Troiano), it just strikes me as a bit too formal in this context.