1. A method comprising: executing an application in a user-mode hardware-protected isolation container (UMHPIC), the UMHPIC protected by a security-enabled processor that provides at least an exit gate for passing execution out of the UMHPIC and an entry gate for returning execution into the UMHPIC; facilitating, by an UMHPIC-aware platform adaptation layer executing in the UMHPIC, a system service request interaction between the application and one or more components of a host platform executing outside of the UMHPIC; and performing, by a secure services component of the UMHPIC-aware platform adaptation layer, a security-relevant action as part of the facilitating.