06725289 is referenced by 95 patents.

A subsystem that is able to address a second memory region initiates I/O requests directed to a device that is able to address a first memory region that is different from the second memory region. Requests for memory are mapped at least once, for example from virtual to physical page numbers. The I/O requests are conditionally remapped to pages in the first region as a function of how often they are involved in the I/O operations and would normally otherwise need to be copied. Remapping may also be made conditional on a function of availability of memory in the first region. In a preferred embodiment of the invention, the I/O requests are initiated by a subsystem within a virtual machine, which runs via an intermediate software layer such as a virtual machine monitor on an underlying hardware and software platform. A typical application of the invention is DMA.

Title
Transparent address remapping for high-speed I/O
Application Number
10/124783
Publication Number
6725289 (B1)
Application Date
April 17, 2002
Publication Date
April 20, 2004
Inventor
Kinshuk Govil
Palo Alto
CA, US
Michael Nelson
Alamo
CA, US
Carl A Waldspurger
Atherton
CA, US
Agent
Jeffrey Pearce
US
Assignee
VMware
CA, US
IPC
G06F 12/00
View Original Source