1. In a processing system that monitors operational characteristics of virtualized execution environments, a method comprising: initiating performance monitoring in a primary domain; registering architectural states of a virtual domain with a primary domain performance monitoring component if said states are reported to said component synchronously with a performance monitoring interruption; registering system states of the virtual domain with the primary domain performance monitoring component if said states are reported to said component synchronously with a performance monitoring interruption; monitoring system activity within the virtual domain if the system states are not reported; and associating performance characteristics with the system and architectural states of the virtual domain.