Andrew P Nicholas

US Patent:

7581229, Aug 25, 2009

Filed:

Mar 11, 2005

Appl. No.:

11/078065

Inventors:

Douglas A. Watkins - Bellevue WA, US
Andrew Ernest Nicholas - Bellevue WA, US

Assignee:

Microsoft Corporation - Redmond WA

International Classification:

G06F 9/44
G06F 9/455

US Classification:

719321, 718 1, 703 23, 703 27

Abstract:

A host operating system can take ownership of a device. The host can project the presence of a device proxy (VDP) into a guest operating system. The VDP provides a set of device functions corresponding to the particular device class. Interactions with the VDP in the guest are forwarded to a Virtual Service Provider (VSP) in the host. The VSP maps a set of device class functions onto physical devices through a hardware abstraction and emulation layer. Functions supported directly by a physical device can be delivered to the device by the hardware abstraction layer (HAL). Functions not directly supported can be implemented through the hardware emulation layer (HEL). A uniform and robust set of functions may be made available in the guest regardless of hardware changes in the host, migration to a new host, or use of the device by other competing operating systems.

US Patent:

8533709, Sep 10, 2013

Filed:

Aug 4, 2005

Appl. No.:

11/197614

Inventors:

Andrew Ernest Nicholas - Bellevue WA, US
Rene Antonio Vega - Kirkland WA, US

Assignee:

Microsoft Cororation - Redmond WA

International Classification:

G06F 9/455

US Classification:

718 1

Abstract:

A catch-up mode that runs a virtual programmable interrupt timer faster than a nominal rate to prevent time loss in a virtual machine can be implemented. If time loss is determined, a catch-up mode can be initiated to cause increased firings, beyond a nominal rate, of the programmable interrupt timer to adjust the clock of the virtual machine to the clock of the host system. The virtual programmable interrupt timer can also be readjusted to a predetermined nominal rate when the time loss in the guest operating system is determined approximately within a predetermined tolerance range. The catch-up mode can be monitored to avoid “interrupt storms” on the virtual machine. The virtual programmable interrupt timer can be altered by the guest operating system to accommodate different operating systems.

US Patent:

8607009, Dec 10, 2013

Filed:

Jul 13, 2006

Appl. No.:

11/487031

Inventors:

Andrew Ernest Nicholas - Bellevue WA, US
Aaron S. Giles - Issaquah WA, US
Eric P. Traut - Bellevue WA, US
Idan Avraham - Seattle WA, US
Xiongjian Fu - Sammamish WA, US
Osama M. Salem - Sammamish WA, US

Assignee:

Microsoft Corporation - Redmond WA

International Classification:

G06F 12/00

US Classification:

711162, 711 6, 711E12103

Abstract:

Various mechanisms are disclosed herein for the saving and restoring of virtual machine environment state. For example, virtual machine state can be either be saved or (multiple) snapshots can be taken of the virtual machine state. In the latter case, virtual processors can be allowed to run while the memory of the virtual machine state is being saved. In either case, virtual devices associated with the virtual machine environment can be quiesced such that these devices can prepare themselves to be saved. Once such virtual devices and memory are saved, they can also be restored. For example, restoration of memory can occur while virtual processors are running at the same time. And, moreover, restoration can occur in batches of pages, thus optimizing the response time for restoring saved data.

US Patent:

8612633, Dec 17, 2013

Filed:

Mar 31, 2010

Appl. No.:

12/752014

Inventors:

Lawrence R. Cleeton - Sammamish WA, US
Andrei Warkentin - Sammamish WA, US
Andrew Nicholas - Bellevue WA, US
Rene Antonio Vega - Kirkland WA, US
Jacob Oshins - Seattle WA, US
John A. Starks - Seattle WA, US

Assignee:

Microsoft Corporation - Redmond WA

International Classification:

G06F 3/00
G06F 9/455

US Classification:

710 5, 703 24, 703 25, 718 1

Abstract:

Techniques for reducing virtual machine input/output emulation overhead and decreasing the attack surface of a virtual machine architecture are disclosed.

US Patent:

20110246986, Oct 6, 2011

Filed:

Mar 31, 2010

Appl. No.:

12/751991

Inventors:

Andrew Nicholas - Bellevue WA, US
Rich Yampell - Bellevue WA, US
Jacob Oshins - Seattle WA, US
Rene Antonio Vega - Kirkland WA, US

Assignee:

Microsoft Corporation - Redmond WA

International Classification:

G06F 9/455

US Classification:

718 1

Abstract:

Techniques for creating crash data in a virtualized environment are disclosed. In an embodiment of the present disclosure the techniques can be used when a guest operating system within a virtual machine may not have a sufficient mechanism for generating crash data.

US Patent:

20120278800, Nov 1, 2012

Filed:

Apr 27, 2011

Appl. No.:

13/095671

Inventors:

Andrew Nicholas - Bellevue WA, US
Rene Antonio Vega - Scotts Valley CA, US
Shuvabrata Ganguly - Seattle WA, US
Ellsworth Davis Walker - Seattle WA, US
Manish Chablani - Redmond WA, US

Assignee:

Microsoft Corporation - Redmond WA

International Classification:

G06F 9/455

US Classification:

718 1

Abstract:

In an exemplary embodiment, one or more virtual processors can be added or removed from a virtual machine based on CPU pressure measured within the virtual machine. In addition to the foregoing, other techniques are described in the detailed description, claims, and figures that form a part of this document.