System and method for preventing user O.S. in VMM system from deenergizing device being used by service O.S.

1. A method comprising:

providing a user operating system (UOS) in a computer and configured to establish a low power state, wherein at least one device associated with the computer is caused to enter a reduced energy consumption mode;

providing a virtual machine monitor (VMM) in the computer;

providing a service operating system (SOS) in the computer; and

selectively preventing the UOS from causing a device to enter the reduced energy consumption mode.

2. The method of claim 1 , comprising using the VMM to intercept reduced energy consumption mode calls from the UOS.

3. The method of claim 2 , wherein the VMM determines whether a UOS call to BIOS is related to a device with which the SOS should interact prior to entering the reduced energy consumption mode, and if so, the VMM prevents the call from passing to BIOS until the SOS has completed its interaction with the device.

4. The method of claim 3 , wherein the VMM informs the UOS that the device enters the reduced operating mode prior to completion of interaction between the device and SOS.

5. The method of claim 3 , wherein the VMM determines whether a UOS call to BIOS, intended to cause a device to enter the reduced energy consumption mode, is related to a device with which the SOS should interact at least in part based on a device identification in a call from the UOS indicating the device is a virtual device.

6. The method of claim 5 , wherein the device identification sent in the call from the UOS is derived from a UOS advanced configuration and power interface (ACPI) table associated with the UOS.

7. The method of claim 6 , wherein the UOS ACPI table is the same as an ACPI table in BIOS except for virtual device identifications in the UOS ACPI table being reflected as real device identifications in the table in BIOS.

8. The method of claim 7 , wherein an SOS ACPI table is associated with the SOS, the SOS ACPI table having a real device identification for each device in the UOS ACPI table having a virtual device identification and a virtual device identification for each device in the UOS ACPI table having a real device identification.

9. The method of claim 7 , wherein an SOS ACPI table is associated with the SOS, the SOS ACPI table having a real device identification for at least one device in the UOS ACPI table having a real device identification.

10. A computer, comprising:

at least one user operating system (UOS);

at least one service operating system (SOS) configured for operating simultaneously with the UOS;

a virtual machine monitor configured for coordinating operation of the UOS and SOS; and

at least one device reconfigurable in response to a call originated by the UOS, wherein the call is intercepted by the virtual machine monitor and if the call is for a real device from the UOS, the virtual machine monitor immediately sends the call on for execution thereof, and otherwise the virtual machine monitor delays sending the call on until the SOS has no further need of the device.

11. The computer of claim 10 , further comprising:

at least one basic input output system (BIOS) configured to communicate with the virtual machine monitor and to receive the call from the UOS, wherein if the virtual machine monitor delays sending the call to the BIOS until the SOS has no further need of the device, the virtual machine monitor sends the call to BIOS for execution thereof when the SOS has no further need of the device.

12. The computer of claim 11 , wherein the virtual machine monitor signals to the UOS that the call has been executed prior to the SOS having no further need of the device.

13. The computer of claim 11 , wherein the virtual machine monitor delays sending the call to the BIOS at least in part based on a device identification in the call from the UOS indicating the device is a virtual device.

14. The computer of claim 13 , wherein the device identification sent in the call from the UOS is derived from a UOS advanced configuration and power interface (ACPI) table associated with the UOS.

15. The computer of claim 14 , wherein the UOS ACPI table is the same as an ACPI table in BIOS except for virtual device identifications in the UOS ACPI table being reflected as real device identifications in the table in BIOS.

16. The computer of claim 15 , wherein an SOS ACPI table is associated with the SOS, the SOS ACPI table having a real device identification for each device in the UOS ACPI table having a virtual device identification and a virtual device identification for each device in the UOS ACPI table having a real device identification.

17. The computer of claim 15 , wherein an SOS ACPI table is associated with the SOS, the SOS ACPI table having a real device identification for at least one device in the UOS ACPI table having a real device identification.

18. A tangible computer readable medium executable by a digital processor to:

intercept at least one call from a user operating system (UOS) to a basic input out system (BIOS) to configure a connected device into a demanded mode;

determine whether a service O.S. (SOS) is in need of the device and if so:

inform the UOS that the device has been configured as ordered, while allowing the SOS to complete its task with the device;

otherwise and at the completion of the SOS task with the device, pass the call to BIOS to configure the device in the demanded mode.

19. The tangible computer readable medium of claim 18 , wherein the digital processor, to determine whether the SOS is in need of the device, uses a device identification in a call from the UOS indicating the device is a virtual device.

20. The tangible computer readable medium of claim 19 , wherein the device identification sent in the call from the UOS is derived from a UOS advanced configuration and power interface (ACPI) table associated with the UOS.

21. The tangible computer readable medium of claim 20 , wherein the UOS ACPI table is the same as an ACPI table in BIOS except for virtual device identifications in the UOS ACPI table being reflected as real device identifications in the table in BIOS.