Method and apparatus to implement logical partitioning of PCI I/O slots

A method for enforcing logical partitioning of direct memory access addresses within a logically partitioned data processing system, the method comprising:

• said logically partitioned system including a hypervisor that permits simultaneous execution of independent operating system images in the logically partitioned system by creating and enforcing partitioning of a logically partitioned platform that includes processors, memory, and input/output slots,
• receiving a request within said hypervisor from a requesting device to access an input/output slot address;
• determining, by said hypervisor, a partition identifier of said requesting device;
• using, by said hypervisor, said partition identifier to prohibit devices within one logical partition from accessing the input/output slots assigned to a different logical partition;
• responsive to a determination that the request is a direct memory access operation, determining, by a DMA address checking component, whether the address is assigned to the same partition as the requesting device;
• responsive to a determination that the address is assigned to a different partition as the requesting device, denying by said DMA address checking component, access to the address;
• and
• processing non-direct-memory access requests by said hypervisor and processing direct memory access requests by said DMA address checking component.

A computer program product in a computer readable media for use in a logically partitioned data processing system for enforcing logical partitioning of direct memory access addresses within the data processing system, the computer program product comprising:

• said logically partitioned system including a hypervisor that permits simultaneous execution of independent operating system images in the logically partitioned system by creating and enforcing partitioning of a logically partitioned platform that includes processors, memory, and input/output slots,
• instructions for receiving a request within said hypervisor from a requesting device to access an input/output slot address;
• instructions for determining, by said hypervisor, a partition identifier of said requesting device;
• instructions for using, by said hypervisor, said partition identifier to prohibit devices within one logical partition from accessing the input/output slots assigned to a different logical partition;
• instructions, responsive to a determination that the request is a direct memory access operation, for determining, by a DMA address checking component, whether the address is assigned to the same partition as the requesting device;
• instructions, responsive to a determination that the address is assigned to a different partition as the requesting device, for denying, by said DMA address checking component access to the address;
• and
• instructions for processing non-direct-memory-access requests by said hypervisor and for processing direct-memory-access-requests by said DMA address checking component.