Abstract: In one embodiment, a method includes transitioning control to a virtual machine (VM) upon receiving a request from a virtual machine monitor (VMM), determining that the request to transition control is associated with a request to be informed of an open event window, performing an event window check to determine whether an even window of the VM is open, and transitioning control to the VMM if the event window check indicates that the event window of the VM is open.

Abstract: In one embodiment, a method for handling privileged events in a virtual machine environment includes detecting an occurrence of a privileged event, determining which one of multiple virtual machine monitors (VMMs) is to handle the privileged event, and transitioning control to this VMM.

Abstract: Methods and systems to provide support for single stepping a virtual machine in a virtual machine environment are disclosed. An exemplary method may include receiving a request to transition control to a virtual machine (VM) from a virtual machine monitor (VMM), determining that a single-stepping indicator is set to a single stepping value, and transitioning control to the VM. Further, if an execution of a first instruction in the VM completes successfully, control is transitioned to the VMM following the successful completion of the execution of the first instruction.

Abstract: In one embodiment, a method for supporting address translation in a virtual-machine environment includes creating a guest translation data structure to be used by a guest operating system for address translation operations, creating an active translation data structure based on the guest translation data structure, and periodically modifying the content of the active translation data structure to conform to the content of the guest translations data structure. The content of the active translation data structure is used by a processor to cache address translations in a translation-lookaside buffer (TLB).

Abstract: In one embodiment, information pertaining to a first fault occurring during operation of a virtual machine (VM) is stored in a first field. A second fault is detected while delivering the first fault to the VM, and a determination is made as to whether the second fault is associated with a transition of control to a virtual machine monitor (VMM). If this determination is positive, information pertaining to the second fault is stored in a second field, and control is transitioned to the VMM.

Abstract: In one embodiment, an apparatus includes a set of multiplex blocks coupled with an interrupt controller and multiple interrupt request lines, and a virtual machine monitor block (VMM) coupled to the set of multiplex blocks. Each multiplex block corresponds to a distinct interrupt request line. Each multiplex block is to route the interrupt request signal received via the corresponding interrupt request line either to the interrupt controller or the VMM block depending on a current configuration value of this multiplex block.

Abstract: A method and apparatus for constructing host processor soft devices independent of the host processor operating system are provided. In one embodiment, a driver of a soft device is implemented in a virtual machine monitor (VMM), and the soft device is made available for use by one or more virtual machines coupled to the VMM. In an alternative embodiment, a software component of a soft device is implemented in a first virtual machine that is coupled to a VMM, and the soft device is made available for use by a second virtual machine coupled to the VMM.

Abstract: Embodiments of apparatuses, methods, and systems for delivering an interrupt to a virtual processor are disclosed. In one embodiment, an apparatus includes an interface to receive an interrupt request, delivery logic, and exit logic. The delivery logic is to determine, based on an attribute of the interrupt request, whether the interrupt request is to be delivered to the virtual processor. The exit logic is to transfer control to a host if the delivery logic determines that the interrupt request is not to be delivered to the virtual processor.

Abstract: In one embodiment, a method includes recognizing an interrupt pending during an operation of guest software, determining that the interrupt is to cause a transition of control to a virtual machine monitor (VMM), determining whether the interrupt is to be acknowledged prior to the transition of control to the VMM, and if the interrupt is to be acknowledged, acknowledging the interrupt and transitioning control to the VMM.

Abstract: In one embodiment, a method for providing power management via virtualization includes monitoring the utilization of a host platform device by one or more virtual machines and managing power consumption of the host platform device based on the results of monitoring.

Abstract: Transitions among schedulable entities executing in a computer system are tracked in computer hardware or in a virtual machine monitor. In one aspect, the schedulable entities are operating system processes and threads, virtual machines, and instruction streams executing on the hardware. In another aspect, the schedulable entities are processes or threads executing within the virtual machines under the control of the virtual machine monitor. The virtual machine monitor derives scheduling information from the transitions to enable a virtual machine system to guarantee adequate scheduling quality of service to real-time applications executing in virtual machines that contain both real-time and non-real-time applications. In still another aspect, a parent virtual machine monitor in a recursive virtualization system can use the scheduling information to schedule a child virtual machine monitor that controls multiple virtual machines.

Abstract: In one embodiment, an apparatus includes a set of multiplex blocks coupled with an interrupt controller and multiple interrupt request lines, and a virtual machine monitor block (VMM) coupled to the set of multiplex blocks. Each multiplex block corresponds to a distinct interrupt request line. Each multiplex block is to route the interrupt request signal received via the corresponding interrupt request line either to the interrupt controller or the VMM block depending on a current configuration value of this multiplex block.

Abstract: In one embodiment, a command pertaining to one or more portions of a register is received from guest software. Further, a determination is made as to whether the guest software has access to all of the requested portions of the register based on indicators within a mask field that correspond to the requested portions of the register. If the guest software has access to all of the requested portions of the register, the command received from the guest software is executed on the requested portions of the register.

Abstract: In one embodiment, when it is determined that a modification of content of an active address translation data structure is required, an entry in the active address translation data structure is modified to conform to a corresponding entry in a guest address translation data structure. During the modification, a bit field including one or more access control indicators in the entry of the active address translation data structure is not overwritten with corresponding data from the guest address translation data structure.

Abstract: In some embodiments, the invention involves a system to deprivilege components of a virtual machine monitor and enable deprivileged service virtual machines (SVMs) to handle selected trapped events. An embodiment of the invention is a hybrid VMM operating on a platform with hardware virtualization support. The hybrid VMM utilizes features from both hypervisor-based and host-based VMM architectures. In at least one embodiment, the functionality of a traditional VMM is partitioned into a small platform-dependent part called a micro-hypervisor (MH) and one or more platform-independent parts called service virtual machines (SVMs). The micro-hypervisor operates at a higher virtual machine (VM) privilege level than any SVM, while the SVM and other VMs may still have access to any instruction set architecture (ISA) privilege level. Other embodiments are described and claimed.

Abstract: In one embodiment, a method for resolving address space conflicts includes detecting that a guest operating system attempts to access a region occupied by a first portion of a virtual machine monitor and relocating the first portion of the virtual machine monitor within the first address space to allow the guest operating system to access the region previously occupied by the first portion of the virtual machine monitor.

Abstract: In one embodiment, a method includes transitioning control to a virtual machine (VM) from a virtual machine monitor (VMM), determining that a VMM timer indicator is set to an enabling value, and identifying a VMM timer value configured by the VMM. The method further includes periodically comparing a current value of a timing source with the VMM timer value, generating an internal event if the current value of the timing source has reached the VMM timer value, and transitioning control to the VMM in response to the internal event without incurring an event handling procedure in any one of the VMM and the VM.

Abstract: One embodiment of the invention is method for resolving address space conflicts between a virtual machine monitor and a guest operating system. The method includes allocating an address space for the operating system and an address space for the monitor. The method also includes mapping a portion of the monitor into the address space allocated for the operating system and the address space allocated for the monitor, and locating another portion of the monitor in the address space allocated for the monitor. The method also includes detecting that the operating system attempts to access a region occupied by the portion of the monitor within the address space allocated for the operating system, and relocating that portion of the monitor within that address space to allow the operating system to access the region previously occupied by that portion of the monitor.

Abstract: A method for managing IO requests from a virtual machine to access IO resources on a physical machine includes determining a request priority associated with an IO request. The IO request is placed in an appropriate queue in response to determining the request priority.

Abstract: In one embodiment, an apparatus includes a set of multiplex blocks coupled with an interrupt controller and multiple interrupt request lines, and a virtual machine monitor block (VMM) coupled to the set of multiplex blocks. Each multiplex block corresponds to a distinct interrupt request line. Each multiplex block is to route the interrupt request signal received via the corresponding interrupt request line either to the interrupt controller or the VMM block depending on a current configuration value of this multiplex block.