Patent ID: 7539841

Claim:
A processing system comprising: a memory for storing program instructions and data; a processor for executing said program instructions, said program instructions including multiple operating systems executing within multiple virtual machines, wherein said program instructions further comprise hypervisor program instructions for managing said virtual machines, and wherein said hypervisor program instructions comprise program instructions for maintaining a reverse mapping structure that maps machine memory blocks within said processing system to physical memory blocks used within each virtual machine, said reverse mapping structure containing an indication for each active machine memory block of each virtual machine using said active machine memory block and one or more associated physical memory blocks within each virtual machine; determining that a particular machine memory block is physically unavailable for access due to a power management state change or a hardware failure; responsive to determining that said particular machine memory block is physically unavailable for access, reading said reverse mapping structure for each of said virtual machines, to determine a set of affected virtual machines that are using said particular machine memory block and associated physical memory blocks; and preventing further failure within said processing system due to said physical unavailability of said particular machine memory block by taking preventative action for each of said set of affected virtual machines.