I still think there is a reasonable case to claim that this usage is right to check whether it is running as a guest. Look at what it is trying to do ... change the behavior of the platform w.r.t. logging of memory errors. How does that make any sense for a guest ... that doesn't even know what memory is present on the platform. Or have guarantees that what it sees as memory address 0x12345678 maps to the same set of cells in a DRAM from one second to the next? -Tony