The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 14, 2014
Filed:
Sep. 16, 2010
Michael Tsirkin, Yokneam, IL;
Christopher M. Wright, Portland, OR (US);
Michael Tsirkin, Yokneam, IL;
Christopher M. Wright, Portland, OR (US);
Red Hat Israel, Ltd., Raanana, IL;
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.