What:		/sys/firmware/cca/realm_guest
Date:		September 2026
Contact:	Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org>
Description:	Read-only. Present only when the kernel is running as an
		Arm Confidential Compute Architecture (CCA) Realm guest, in
		which case it reads 1. If the file does not exist, the kernel
		is not running as a Realm guest.