Methods and systems to manage machine state in virtual machine operations

• US 20040123288A1
• Filed: 12/19/2002
• Published: 06/24/2004
• Est. Priority Date: 12/19/2002
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Neiger, Gilbert, Bennett, Steven M., Jeyasingh, Stalinselvaraj, Uhlig, Richard A., Cota-Robles, Erik C., Kagi, Alain, Kozuch, Michael A.
• Granted Patent: US 7,793,286 B2
• Time in Patent Office: Days
• US Class Current: 718/1
• CPC Class Codes: G06F 2009/4557 Distribution of virtual machine instances; Migration and load balancing
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects

Abstract

Methods and systems are provided to control transitions between a virtual machine (VM) and Virtual Machine Monitor (VMM). A processor uses state action indicators to load and/or store associated elements of machine state before completing the transition. The state action indicators may be stored in a Virtual Machine Control Structure (VMCS), predetermined, and/or calculated dynamically. In some embodiments, the values loaded can be directly acquired from the VMCS, predetermined and/or calculated dynamically. In some embodiments, the values stored may be acquired directly from machine state, predetermined and/or calculated dynamically.

Claims

1. A method to manage a Virtual Machine (VM) operation, comprising:

identifying a VM transition operation to be processed;

identifying one or more state-action indicators; and

using one or more values of the one or more state-action indicators to determine at least one action on one or more associated elements of a machine state, if necessary.

2. The method of claim 1 wherein in identifying, the one or more state-action indicators is associated with at least one of the VM transition operation, the one or more associated elements of the machine state, and a second element of the machine state.

3. The method of claim 1 wherein in using, the at least one action includes at least one of loading the one or more associated elements of the machine state, storing the one more associated elements of the machine state, and taking no action.

4. The method of claim 1 wherein in identifying, the one or more state action indicators is at least one of:

one or more read values in a Virtual Machine Control Structure (VMCS);

one or more fixed values; and

one or more calculated values based on at least one of;

the one or more associated elements of the machine state;

a second element of the machine state;

an element associated with a state of the VM;

an element associated with a state of a Virtual Machine Monitor (VMM);

a control indicator value; and

a field value in the VMCS.

5. The method of claim 1 wherein in identifying, the one or more state-action indicators is at least one of a data structure describing the at least one associated element of the machine state, and one or more bits in a control vector.

6. The method of claim 1 wherein in using, each at least one action performs at least one of:

storing the one or more associated elements of the machine state to one or more fields in a Virtual Machine Control Structure (VMCS);

storing one or more fixed values to one or more fields in the VMCS; and

storing one or more calculated values to one or more fields in the VMCS.

7. The method of claim 6 wherein in storing the one or more calculated values, the one or more calculated values is determined by:

examining values of at least one of;

an element of the machine state;

a value in a virtual machine control structure (VMCS); and

a control indicator; and

transforming the examined values to form the one or more calculated values.

8. The method of claim 1 wherein in using, each at least one action performs at least one of:

loading the one or more associated elements of the machine state from one or more fields in a Virtual Machine Control Structure (VMCS);

loading one or more calculated machine state values into the one or more associated elements of the machine state; and

loading one or more fixed values into the one or more associated elements of the machine state.

9. The method of claim 8 wherein in loading the one or more calculated machine state values, the one or more calculated machine state values is determined by:

examining values of at least one of;

an element of the machine state;

a value in the Virtual Machine Control Structure (VMCS); and

a control indicator; and

transforming the examined values to form the one or more calculated machine state values.

10. The method of claim 1 wherein in identifying the VM transition operation, the VM transition operation is at least one of a VM entry and a VM exit.

11. A system for managing a Virtual Machine (VM), comprising:

a VM;

a Virtual Machine Monitor (VMM);

a computing device; and

wherein upon a VM transition, the computing device determines one or more state action indicators, the one or more state indicators is used by the computing device to determine at least one action that causes the computing device to store and/or load one or more associated elements of the computing device'"'"'s state, if necessary, before the VM transition is completed.

12. The system of claim 11, wherein the computing device determines one or more values of the one or more state action indicators by at least one of:

acquiring one or more field values from a Virtual Machine Control Structure (VMCS);

determining one or more fixed values; and

calculating one or more calculated values.

13. The system of claim 11, wherein the computing device accesses a Virtual Machine Control Structure (VMCS) that includes two sets of control bits, the first set of control bits are used by the computing device to identify elements of the computing device'"'"'s state to store and elements of the computing device'"'"'s state to load on an entry to the VM, the second set of control bits are used by the computing device to identify elements of the computing device'"'"'s state to store and elements of the computing device'"'"'s state to load on an exit from the VM.

14. The system of claim 11 wherein in storing the one or more associated elements of the computing device'"'"'s state further comprises:

storing the one or more associated elements of the computing device'"'"'s state to one or more fields in a Virtual Machine Control Structure (VMCS);

storing one or more fixed values to the one or more fields in the VMCS; and

storing one or more calculated values to the one or more fields in the VMCS.

15. The system of claim 14 wherein in storing the one or more calculated values, the one or more calculated values is determined by:

examining values of at least one of;

an element of the computing device'"'"'s state;

a value in the VMCS; and

a control indicator; and

transforming the examined values to form the one or more calculated values.

16. The system of claim 11 wherein in loading the one or more associated elements of the computing device'"'"'s state further comprises:

loading at the one or more associated elements of the computing device'"'"'s state from one or more fields in a Virtual Machine Control Structure (VMCS) into the one or more associated elements of the computing device'"'"'s state;

loading one or more calculated values into the one or more associated elements of the computing device'"'"'s state; and

loading one or more fixed values into the one or more associated elements of the computing device'"'"'s state.

17. The system of claim 16 wherein in loading the one or more calculated values, the one or more calculated values is determined by:

examining values of at least one of;

an element of the computing device'"'"'s state;

a value in the VMCS; and

a control indicator value; and

transforming the examined values to form the one or more calculated values.

18. An article having a machine accessible medium having associated instructions, wherein the instructions, when executed, result in a machine comprising at least one component performing:

detecting a need for a Virtual Machine (VM) transition;

resolving one or more state-action indicators and one or more state-action indicator values; and

executing at least one action on the one or more associated elements of a machine state based on the one or more resolved state-action indicator values.

19. The article of claim 18 wherein in detecting, the VM transition is at least one of a VM exit from a Virtual Machine Monitor (VMM) and a VM entry into a VM.

20. The article of claim 18 wherein resolving the one or more state action indicators, the at least one state action indicator is resolved by performing at least one of:

reading at least one indicator value from a Virtual Machine Control Structure (VMCS);

determining one or more fixed values; and

calculating one or more calculated values.

21. The article of claim 20 wherein in calculating, the one or more calculated values is determined by performing at least one of:

using the one or more associated elements of the machine state;

using a second element of the machine state;

using an element associated with a state of the VM;

using an element associated with a state of the VMM;

using a control indicator value; and

using a field value in the VMCS.

22. The article of claim 18 wherein in executing, the at least one action is executed by performing at least one of:

storing the one or more associated elements of machine state;

storing one or more fixed store values;

storing one or more calculated store values;

loading one or more values from one or more fields in a Virtual Machine Control Structure (VMCS) into the one or more associated elements of machine state;

loading one or more fixed load values into the one or more associated elements of machine state; and

loading one or more calculated load values into the one or more associated elements of machine state.

23. The article of claim 18 further comprising completing the VM transition after the at least one action is executed.