1. A method comprising: observing communication from plurality of paravirtualized virtual machines (VMs) to driver domains that are isolated from the plurality of VMs, the communication comprising at least one resource request from the plurality of VMs to the driver domains, comprising observing communication from said plurality of VMs requesting access to a shared resource that is accessible by the plurality of VMs, wherein a device driver for said shared resource is arranged in said driver domains; and determining, based on said communication between the plurality of VMs and the plurality of driver domains, CPU utilization of said plurality of driver domains attributable to the plurality of VMs, including determining a share of CPU execution attributed to each of the VMs during a predetermined time interval.