HardWare Performance Counter (HWPC) Sensor is a tool that monitor the Intel CPU performance counter and the power consumption of CPU.
Hwpc-sensor use the RAPL (Running Average Power Limit) technology to monitor CPU power consumption. This technology is only available on Intel Sandy Bridge architecture or higher.
The sensor use the perf API of the Linux kernel. It is only available on Linux and need to have root access to be used.
The sensor couldn’t be used in a virtual machine, it must access (via Linux kernel API) to the real CPU register to read performance counter values.
HwPC sensor is an open-source project developed by the Spirals research group (University of Lille 1 and Inria).
The documentation is available here