1. In a computer system comprising a host hardware platform, virtualization software running on the host hardware platform, and a virtual machine running on the virtualization software, a method for tracking data correspondences which comprises: monitoring data movement operations of the computer system; and storing information regarding the data movement operations in a data correspondence structure, the information for each of the data movement operations including data correspondence information between a data location in a virtual memory of the virtual machine and a data location in a physical component that is accessible by the computer system, wherein the information for each of the data movement operations further comprises confidence information that provides an estimate of a chance of validity of the data correspondence information for that data movement operation.