While working with Openstack on both VMware virtual machines (with no virtualization instruction set exposed) and physical machines, I found virtual machine instances can be deployed seamlessly. On a machine that does not have virtualization instruction set exposed, KVM falls back to QEMU silently. That is why could I try out OpenStack on virtual machines before my hardware was ready. Because both KVM and QEMU support the same libvirt APIs, you would not notice any difference using command line like virsh, or Virtualization Manager. That is the beauty of standard APIs with different implementations, similar to the standard vSphere APIs that are implemented by both vCenter and ESXi.
My company has created products like vSearch ("Super vCenter"), vijavaNG APIs, EAM APIs, ICE tool. We also help clients with virtualization and cloud computing on customized development, training. Should you, or someone you know, need these products and services, please feel free to contact me: steve __AT__ doublecloud.org.
Me: Steve Jin, VMware vExpert who authored the VMware VI and vSphere SDK by Prentice Hall, and created the de factor open source vSphere Java API while working at VMware engineering. Companies like Cisco, EMC, NetApp, HP, Dell, VMware, are among the users of the API and other tools I developed for their products, internal IT orchestration, and test automation.