Got this reply from a previous post
There are possibilities to do vMotion between rev e & f CPUs ( BL25G1 / BL25G2) , you have to set RDTSCP CPU mask but consider, afterwards only vmotion between 32bit Vms work ( 64bit is not supported)
Use the RDTSCP mask to perform
C <-> D VMotion for 32-bit guest OS.
VMotion is not allowed for 64-bit guest OS.
The mask is supported. (Hinweis: von Vmware)
For instructions on how to apply this mask, see Section 3.5 - To Ignore RDTSCP Restrictions for VC 2.x / ESX 3.x in http://kb.vmware.com/kb/1993
steps
Choose Inventory > Virtual Machine > Edit Settings.
Click the Options tab, and select Advanced.
In the CPU Identification Mask area, click the Advanced button.
The CPU Identification Mask window opens.
Open the CPU Identification Mask window as indicated above.
Click the AMD Override tab.
In the Level 80000001 section, edit the edx row so that it contains the following:
\-- 0- -
-
-
-
-
-
Note: This mask is available, though not fully supported, for VMotion migration of virtual machines running 32-bit guest operating systems only. It is not available for 64-bit guest operating systems.
siehe attached Artikel
» Intel VMotion - KB 1991
» AMD VMotion - KB 1992
We have now moved to x64 bit machines. Is there any change to this or any work around for this issue