Provided is a method and apparatus for registering requests to access
physical memory in a physical address mapping framework. Specifically, a
device can register in the physical address mapping framework before
accessing physical memory, thus permitting an operating system to
identify the device when it is necessary to relocate pages in physical
memory. The physical address mapping framework can be any structure that
permits registration. For example, the structure can be a list or a tree.
When relocating physical memory, all accesses registered in the physical
address mapping framework are restricted. Then, the device is notified to
stop accessing physical memory via information stored in the physical
address mapping framework. After the relocation, the device is notified
to resume accessing physical memory via information stored in the
physical address mapping framework.