Migrating a memory page by modifying a page migration state of a state machine associated with a DMA mapper based on a state notification from an operating system kernel

摘要

An atomic memory migration apparatus and method are provided. With the apparatus and method, all active DMA mappings to a given physical page of memory are identified and future mappings/unmappings to the physical page are serialized with migrations of current mappings. The identified DMA mappings are then disabled at the bus level and the physical page is migrated to a new memory page. All existing DMA mappings are also migrated to the new page. After migration is completed, the DMA mappings, which have now been migrated to the new page, are reenabled at the bus level.