Peripheral device with resource isolation

A peripheral device package for use in a host computing device has a plurality of compute elements and a plurality of resources shared by the plurality of compute elements. A datastructure is stored in a hidden memory of the peripheral device package. The data structure holds metadata about ownership of resources of the peripheral device package by a plurality of user runtime processes of the host computing device which use the compute elements. At least one of the user runtime processes is a secure user runtime process. The peripheral device package has a command processor configured to use the datastructure to enforce isolation of the resources used by the secure user runtime process.