This patch is for XenServer.
1. Local testing on XenServer 6.0.2
2. Successfully got up system VMs
3. Successfully created a CentOS VM
4. Created VM snapshot and reverted to snapshot
5. Manipulated guest_os_hypervisor table for mapping, and checked for correct propagation of platform emulator.
Signed off by :- Nitin Mehta<nitin.mehta@citrix.com>