Invention Grant
- Patent Title: Direct memory access filter for virtualized operating systems
- Patent Title (中): 用于虚拟化操作系统的直接内存访问过滤器
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Application No.: US12242761Application Date: 2008-09-30
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Publication No.: US08151032B2Publication Date: 2012-04-03
- Inventor: Jacob Oshins
- Applicant: Jacob Oshins
- Applicant Address: US WA Redmond
- Assignee: Microsoft Corporation
- Current Assignee: Microsoft Corporation
- Current Assignee Address: US WA Redmond
- Agency: Lee & Hayes, PLLC
- Main IPC: G06F12/00
- IPC: G06F12/00

Abstract:
Described techniques increase runtime performance of workloads executing on a hypervisor by executing virtualization-aware code in an otherwise non virtualization-aware guest operating system. In one implementation, the virtualization-aware code allows workloads direct access to physical hardware devices, while allowing the system memory allocated to the workloads to be overcommitted. In one implementation, a DMA filter driver is inserted into an I/O driver stack to ensure that the target guest physical memory of a DMA transfer is resident before the transfer begins. The DMA filter driver may utilize a cache to track which pages of memory are resident. The cache may also indicate which pages of memory are in use by one or more transfers, enabling the hypervisor to avoid appropriating pages of memory during a transfer.
Public/Granted literature
- US20090327576A1 Direct Memory Access Filter for Virtualized Operating Systems Public/Granted day:2009-12-31
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