VIRTUAL PERFORMANCE MONITORING DECOUPLED FROM HARDWARE PERFORMANCE-MONITORING UNITS

摘要

The current document is directed to virtualized PMUs provided by virtualization layers. The currently disclosed virtualized PMUs are decoupled from the underlying PMU hardware features of processors on which the virtualization layer executes. The decoupling is achieved, in part, by time multiplexing the underlying hardware PMU registers to provide a greater number of virtualized PMU registers than the number of hardware-PMU registers provided by at least some of the underlying hardware PMUs. The decoupling is also achieved by providing for monitoring, by the virtualized PMU registers, of computed processor events and approximated processor events in addition to the processor events monitored by the underlying hardware PMUs. In addition, the virtualized PMU registers are implemented, in certain implementations, to support a variety of different monitoring modes, including monitoring of processor events that occur only during execution of the virtualization layer and monitoring of hardware-thread-specific processor events.

主权项

1. A virtualization layer comprising computer instructions, stored in a physical data-storage device within a virtualized computer system that includes the one or more processors, one or more memories, and one or more physical data-storage devices, that, when executed by one or more of the one or more processors, control the virtualized computer system to:
provide a virtual hardware interface to one or more virtual machines that each includes a guest operating system and one or more application programs that execute within an execution environment provided by the guest operating system; and provide, as a component of the virtual hardware interface, a set of virtual performance monitoring registers that can be accessed by the one or more of the guest operating systems and that are not constrained to correspond in number or function to the hardware-level performance monitoring registers provided by any one of the one or more processors.