Techniques described herein provide a handshake mechanism and protocol for notifying an operating system whether system hardware supports persistent cache flushing. System firmware may determine whether the hardware is capable of supporting a full flush of processor caches and volatile memory buffers in the event of a power outage or asynchronous reset. If the hardware is capable, then persistent cache flushing may be selectively enabled and advertised to the operating system. Once persistent cache flushing is enabled, the operating system and applications may treat data committed to volatile processor caches as persistent. If disabled or not supported by system hardware, then the platform may not advertise support for persistent cache flushing to the operating system.