Safe userspace device access for network function virtualization using an IOMMU to map supervisor memory to a reserved range of application virtual addresses

摘要

A device access system includes a memory having a supervisor memory, a processor, an input output memory management unit (IOMMU), and a supervisor. The supervisor includes a supervisor driver, which executes on the processor to allocate the supervisor memory and reserve a range of application virtual addresses. The supervisor driver programs the IOMMU to map the supervisor memory to the reserved range. A device is granted access to the reserved range, which is protected in host page table entries such that an application cannot modify data within the range. The supervisor driver configures the device to use the supervisor memory and receive a request including a virtual address and length from the application to use the device. The supervisor driver validates the request by verifying that the virtual address and length do not overlap the range reserved by the supervisor, and responsive to validating the request, submits the request to the device.