Memory overcommit by using an emulated IOMMU in a computer system with a host IOMMU
US8631170B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 2010 |
| Grant date | Jan 14, 2014 |
| Priority date | — |
| Expiry date | Jan 1, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/151
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and system for managing direct memory access (DMA) in a computer system that hosts virtual machines and allows memory overcommit. The computer receives an indication that a bus address is to be used by a device to perform DMA to a buffer. In response to the indication, the computer determines a host device identifier for the device, and pins a memory page addressed by a host address that is associated with the bus address and a guest address. The computer also records, in a host I/O memory management unit (IOMMU), a mapping of the bus address and the host device identifier to the host address. After the device completes the DMA, the computer removes the mapping from the host IOMMU to prevent further direct access to the host address.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.