The work described in this paper was made possible by many people. We thank our management for supporting this work. We acknowledge the many past and present members of the Xen* team in the Intel® Open Source Technology Center for the many hours they spent developing and testing this code. Felix Leung, Alberto Munoz, and Mary Xie have provided immeasurable help for the VT-i project. A special thanks goes to Ian Pratt and Keir Fraser for working the full virtualization issues with us. Leendert van Doorn is the creator of the VMXAssist logic to execute real mode code. Their guidance and assistance throughout the course of this project has been invaluable.