This presentation is based on the technical hurdles we overcame when building a commercial product on the introspection capabilities of the Xen hypervisor. Mihai Dontu will relate the importance of the x86 emulator, the need for a more focused effort on its completeness and correctness, the problems encountered, and the solutions adopted. He will also approach the subject of performance, for which hypervisor features that were not meant to be in the hot path had to be punctually reworked to solve a key requirement for making a theoretical product a commercial reality.