Abstract: This document describes tools capable of making a portion of operating-system memory associated with a protection agent unalterable or inaccessible from an operating-system privilege mode. In some embodiments, these tools are capable of creating a protection-agent privilege mode by requesting that a virtual machine monitor protect this portion of operating-system memory. In other embodiments, these tools are capable of creating the protection-agent privilege mode by virtualizing a physical processor into multiple virtual processors, at least one of which is a protection-agent virtual processor designed to run the protection agent. By making this portion of operating-system memory unalterable or inaccessible from the operating-system privilege mode, the protection agent may be less vulnerable to attacks by entities operating within the operating-system privilege mode.

Abstract: This document describes tools capable of enabling a protection agent to determine, from memory inaccessible from an operating-system privilege mode, whether one or more resources of an operating system have been modified. In some instances, these tools may enable the protection agent to reside within a virtual machine monitor. In other instances, the tools may enable the protection agent to reside within a distinct virtual partition provided by the virtual machine monitor. By operating outside of the operating-system privilege mode, the protection agent may be less vulnerable to attacks by entities operating within the operating-system privilege mode.

Abstract: This document describes tools capable of enabling a protection agent to determine, from memory inaccessible from an operating-system privilege mode, whether one or more resources of an operating system have been modified. In some instances, these tools may enable the protection agent to reside within a virtual machine monitor. In other instances, the tools may enable the protection agent to reside within a distinct virtual partition provided by the virtual machine monitor. By operating outside of the operating-system privilege mode, the protection agent may be less vulnerable to attacks by entities operating within the operating-system privilege mode.

Abstract: Efficient power management of a system with virtual machines is disclosed. In particular, such efficient power management may enable coordination of system-wide power changes with virtual machines. Additionally, such efficient power management may enable coherent power changes in a system with a virtual machine monitor. Furthermore, such efficient power management may enable dynamic control and communication of power state changes.

Abstract: An operating system is described that is capable of ascertaining whether it is executing in a virtual machine environment and is further capable of modifying its behavior to operate more efficiently and provide optimal behavior in a virtual machine environment. An operating system is enlightened so that it is aware of VMMs or hypervisors, taking on behavior that is optimal to that environment. The VMM or hypervisor informs the operating system of the optimal behavior, and vice versa.

Abstract: Resource management architectures implemented in computer systems to manage resources are described. In one embodiment, a general architecture includes a resource manager and multiple resource providers that support one or more resource consumers such as a system component or application. Each provider is associated with a resource and acts as the manager for the resource when interfacing with the resource manager. The resource manager arbitrates access to the resources provided by the resource providers on behalf of the consumers. A policy manager sets various policies that are used by the resource manager to allocate resources. One policy is a priority-based policy that distinguishes among which applications and/or users have priority over others to use the resources. A resource consumer creates an “activity” at the resource manager and builds one or more “configurations” that describe various sets of preferred resources required to perform the activity.

Abstract: Resource management architectures implemented in computer systems to manage resources are described. In one embodiment, a general architecture includes a resource manager and multiple resource providers that support one or more resource consumers such as a system component or application. Each provider is associated with a resource and acts as the manager for the resource when interfacing with the resource manager. The resource manager arbitrates access to the resources provided by the resource providers on behalf of the consumers. A policy manager sets various policies that are used by the resource manager to allocate resources. One policy is a priority-based policy that distinguishes among which applications and/or users have priority over others to use the resources. A resource consumer creates an “activity” at the resource manager and builds one or more “configurations” that describe various sets of preferred resources required to perform the activity.

Abstract: An improved compressed file system is provided. In a preferred embodiment of the present invention, a memory cache is used for storing uncompressed data that is sent to or received from a compressed logical drive. When writing data to the compressed logical drive, the preferred embodiment of the present invention determines whether to use write-behind caching or write-through caching.

Abstract: The present invention is directed to a facility for performing selected operations as part of a booting process of a computer system only during iterations of the booting process that immediately follow failed iterations of the booting process. At the beginning of the booting process, the facility copies a persistent instance of a flag indicating whether the iteration of the booting process at the current iteration of the booting process immediately follows fail to a temporary instance of the flag. The facility then assigns the persistent instance of the flag to the set condition so that, if the current iteration of the booting process fails before completing, the flag will reflect that the current iteration of the booting process failed. When each selected operation is encountered during the current iteration of the booting process, the facility performs that selected operation only if the temporary instance of the flag is set.

Abstract: An improved compressed file system is provided. In a preferred embodiment of the present invention, a memory cache is used for storing uncompressed data that is sent to or received from a compressed logical drive. When writing data to the compressed logical drive, the preferred embodiment of the present invention determines whether to use write-behind caching or write-through caching.

Abstract: In a computer network including a plurality of interconnected computers, one of the computers being a sleeping computer in a power down state, the sleeping computer having a list of packets to listen for stored on a network interface card associated with the sleeping computer, a method of waking the sleeping computer from the computer network. An incoming packet of information is transmitted from one of the computers in the network to the sleeping computer. When the network interface card of the sleeping computer detects the incoming packet, it compares the incoming packet to the list of packets stored on the network interface card. If the incoming packet matches one of the packets in the list of packets stored on the network interface card, or if the incoming packet is directly addressed to the sleeping computer, then a signal is issued to wake the sleeping computer. Otherwise, the incoming packet is discarded and the sleeping computer is not awaken.

Abstract: A computer includes a housing, a processor positioned in the housing, and an external bus adapter configured to allow the processor to access consumer electronics devices positioned outside of the housing using an external bus. The processor is configured to produce a first digital audio signal, to mix the first digital audio signal with a second digital audio signal to produce a unified digital audio signal, and to transmit the unified digital audio signal to a consumer electronics device using the external bus.