It has been a while since I worked with VM, and I can only recall one vendor product that bothered to check to see if it was running on an unauthorized CPU under VM.
In order to do that check, a program would first do the normal CPU serial number check. Even when the VM directory provides a virtual CPU serial number, the high order byte is X'FF', so a program checking the CPU serial number knows it is running on a virtual machine. I seem to recall that there is a machine instruction of some sort that when running under VM will return the real CPU serial and model information. The virtual machine must have the authority to issue that instruction. If it did not have the authority, some sort of error is returned or condition code set. The vendor product therefore required that if it was used on a virtual machine, the virtual machine have the authority to issue the necessary machine instruction. If it did not, the product considered the product to be running on an unauthorized CPU. Jeffrey Holst Systems Administator Senior Technology and Operations, Shared Services PNC Bank The contents of this email are the property of PNC. If it was not addressed to you, you have no legal right to read it. If you think you received it in error, please notify the sender. Do not forward or copy without permission of the sender. This message may be considered a commercial electronic message under Canadian law or this message may contain an advertisement of a product or service and thus may constitute a commercial electronic mail message under US law. You may unsubscribe at any time from receiving commercial electronic messages from PNC at http://pages.e.pnc.com/globalunsub/ PNC, 249 Fifth Avenue, Pittsburgh, PA 15222; pnc.com ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
