Patent•
Switching between multiple software entities using different operating modes of a processor in a computer system
21 Apr 2004-
TL;DR: In this article, a switching routine is implemented to switch from one operating mode to another and to transfer control from one software entity to another, such as a host operating system and a virtual machine monitor.
Abstract: A processor has multiple operating modes, such as the long/compatibility mode, the long/64-bit mode and the legacy modes of the x86-64 microprocessor. Different software entities execute in different ones of these operating modes. A switching routine is implemented to switch from one operating mode to another and to transfer control from one software entity to another. The software entities may be, for example, a host operating system and a virtual machine monitor. Thus, for example, a virtual computer system may comprise a 64-bit host operating system and a 32-bit virtual machine monitor, executing on an x86-64 microprocessor in long mode and legacy mode, respectively, with the virtual machine monitor supporting an x86 virtual machine. The switching routine may be implemented partially or completely in an identity-mapped memory page. Execution of the switching routine may be initiated by a driver that is installed in the host operating system of a virtual computer system.
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Patent•
15 Mar 2012TL;DR: In this article, a high-level object-oriented specification language for configurable components of a cloud-based deployment is proposed, which allows configurable component models to be modeled by a class definition that includes a group of configurable class parameters.
Abstract: A high-level object-oriented specification language allows configurable components of a cloud-based deployment to be modeled by a class definition that includes a group of configurable class parameters. The object-oriented specification language supports extension of an existing base class definition to create new class definitions, and supports inheritance of class parameters from the existing base class definition by the new class definitions. A cloud-based deployment can be customized based on class definitions used in configuring one or more generic deployments, such as by modifying class parameter values of the class definitions, varying interrelationships between the classes, and supplementing existing class parameters with new class parameters. The high-level object-oriented specification language supports class definitions that model hardware and virtual resources as well as software roles and service roles served by software applications and services in a cloud-based deployment. Syntax for specifying dependency and connectivity between classes is also provided.
221 citations
Patent•
29 Aug 2006TL;DR: Hierarchical virtualization as discussed by the authors uses a hypervisor that maintains a first partition and uses a virtualization stack within the first partition to create and control a second partition, where a child partition can have exclusive control over a portion or all of its resources with respect to a parent partition.
Abstract: Hierarchical virtualization is disclosed, where such virtualization can be accomplished with a multi-level mechanism. The hierarchical virtualization includes using a hypervisor that maintains a first partition and using a virtualization stack within the first partition to create and control a second partition. Multiple virtualization stacks can subsist within the first partition, and each such virtualization stack can create and control multiple partitions. In one particular implementation, a child partition can have exclusive control over a portion or all of its resources with respect to a parent partition. The hypervisor as the ultimate arbiter in such a virtualized environment enforces such a setup and is able to communicate directly within any partition within the virtualized hierarchy.
146 citations
Patent•
26 Apr 201178 citations
References
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Patent•
10 Sep 1998TL;DR: In this paper, a virtual machine monitor (VMM) is included in a computer system that has a protected host operating system (HOS) and a VMM is connected to the VMM.
Abstract: A virtual machine monitor (VMM) is included in a computer system that has a protected host operating system (HOS). A virtual machine running at least one application via a virtual operating system is connected to the VMM. Both the HOS and the VMM have separate operating contexts and disjoint address spaces, but are both co-resident at system level. A driver that is downloadable into the HOS at system level forms a total context switch between the VMM and HOS contexts. A user-level emulator accepts commands from the VMM via the system-level driver and processes these commands as remote procedure calls. The emulator is able to issue host operating system calls and thereby access the physical system devices via the host operating system. The host operating system itself thus handles execution of certain VMM instructions, such as accessing physical devices.
402 citations
Patent•
30 Jun 2004TL;DR: In this article, a virtualized computing system and methods for transitioning in real time between long supermode and legacy supermode in the x86-64 architecture are presented. But the transition code for the processor mode context switch on this page is not executed.
Abstract: The present invention provides a virtualized computing systems and methods for transitioning in real time between LONG SUPER-MODE and LEGACY SUPER-MODE in the x86-64 architecture. In doing so, a virtual machine, which relies on the traditional 32-bit modes, i.e., REAL MODE and PROTECTED MODE (V86 SUB-MODE, RING-0 SUB-MODE, and RING-3 SUB-MODE), is able to run alongside other applications on x86-64 computer hardware (i.e., 64-bit). The method of performing a temporary processor mode context switch includes the steps of the virtual machine monitor's setting up a “virtual=real” page, placing the transition code for performing the processor mode context switch on this page, jumping to this page, disabling the memory management unit (MMU) of the x86-64 computer hardware, modifying the mode control register to set either the LONG SUPER-MODE bit or LEGACY SUPER-MODE bit, loading a new page table, and reactivating the MMU of the x86-64 computer hardware.
46 citations