VIRTUAL MACHINE CONTROL DEVICE, VIRTUAL MACHINE CONTROL METHOD, AND VIRTUAL MACHINE CONTROL PROGRAM

• US 20100333100A1
• Filed: 04/22/2009
• Published: 12/30/2010
• Est. Priority Date: 04/28/2008
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Miyazaki, Ryota, Kato, Kazuomi, Saito, Masahiko
• Granted Patent: US 8,468,533 B2
• Time in Patent Office: Days
• US Class Current: 718/103
• CPC Class Codes: G06F 9/4881 Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues

Abstract

In a case where a task execution unit (100) of a first virtual machine (10) executes a dummy task (110) according to task scheduling by an operating system, it notifies a virtual machine control unit (30) of a priority acquired by a priority acquisition unit (122) and a switching indication to switch the first virtual machine (10) currently in operation to a second virtual machine (20). The virtual machine control unit (30) receives the priority and the switching indication notified by the task execution unit (100) and switches the first virtual machine (10) currently in operation to the second virtual machine (20). According to this configuration, it becomes possible to reduce overheads needed to switch virtual machines.

Claims

1. A virtual machine control device, comprising:

a plurality of virtual machines each having an operating system that carries out scheduling of tasks to be executed according to priorities of the tasks; and

a virtual machine control unit that controls switching of the plurality of virtual machines, wherein;

each of the plurality of virtual machines includes

a task execution unit that executes a switching task to perform switching processing by which a virtual machine currently in operation is switched to another virtual machine as a switching target,

a priority acquisition unit that acquires a priority of a task having a highest priority among executable tasks in the currently running virtual machine, and

a priority setting unit that sets the priority acquired by the priority acquisition unit of the another virtual machine to a priority of the switching task;

the task execution unit notifies the virtual machine control unit of the priority acquired by the priority acquisition unit and a switching indication to switch the virtual machine currently in operation to the another virtual machine in a case where the switching task is executed according to task scheduling by the operating system; and

the virtual machine control unit receives the priority and the switching indication notified by the task execution unit and switches the virtual machine currently in operation to the another virtual machine.

2. The virtual machine control device according to claim 1, wherein:

the task execution unit generates the switching task at start-up of the plurality of virtual machines and sets a highest priority to the priority of the generated switching task.

3. The virtual machine control device according to claim 1,

wherein the virtual machine control unit includes:

an interruption reception unit that receives an interruption notice notifying an interruption to the plurality of virtual machines and determines a virtual machine as an interruption target among the plurality of virtual machines using an interruption cause contained in the interruption notice; and

an interruption priority storing determination unit that determines whether a priority correlated with the interruption cause is to be set to a priority of the virtual machine as the interruption target.

4. The virtual machine control device according to claim 3, wherein:

the interruption priority storing determination unit determines whether the virtual machine determined as the interruption target by the interruption reception unit is same as a virtual machine that was operating before the interruption; and

the virtual machine control unit further includes a virtual machine priority setting unit that sets, in a case where it is determined that the virtual machine as the interruption target is not same as the virtual machine that was operating before the interruption, the priority correlated with the interruption cause to the priority of the virtual machine as the interruption target.

5. The virtual machine control device according to claim 3, further comprising:

a priority storing unit that stores the priority notified by the task execution unit,

wherein the virtual machine control unit compares the priority correlated with the interruption cause with the priority stored in the priority storing unit and, in a case where the priority correlated with the interruption cause is higher than the priority stored in the priority storing unit, sets the priority correlated with the interruption cause to the priority of the virtual machine as the interruption target.

6. The virtual machine control device according to claim 1, further comprising:

an execution context storing unit that stores an execution context of each virtual machine,

wherein the virtual machine control unit saves an execution context corresponding to a virtual machine before switching into the execution context storing unit and restores an execution context corresponding to a virtual machine after switching from the execution context storing unit.

7. The virtual machine control device according to claim 6, further comprising:

a priority storing unit that stores the priority notified by the task execution unit, wherein;

the virtual machine control unit saves an execution context corresponding to a virtual machine before switching into the execution context storing unit, stores the priority notified by the task execution unit into the priority storing unit, and restores an execution context corresponding to a virtual machine after switching from the execution context storing unit in a case where the virtual machine control unit receives the priority and the switching indication notified by the task execution unit;

the task execution unit included in the virtual machine after the switching resumes the switching task that has been suspended; and

the priority setting unit included in the virtual machine after the switching acquires the priority of the virtual machine before the switching stored in the priority storing unit and sets the acquired priority to the priority of the switching task.

8. The virtual machine control device according to claim 6, wherein:

the execution context storing unit stores the execution context saved by the virtual machine control unit for each virtual machine;

the task execution unit notifies the virtual machine control unit of a failure priority indicating an occurrence of a failure in a virtual machine currently in operation in a case where the failure occurs in the virtual machine currently in operation; and

the virtual machine control unit restores an oldest execution context among execution contexts stored in the execution context storing unit in a case where the virtual machine control unit receives the failure priority notified by the task execution unit.

9. A virtual machine control method of controlling switching of a plurality of virtual machines each including an operation operating system that carries out scheduling of tasks to be executed according to priorities of the tasks, comprising:

a task executing step of executing a switching task to perform switching processing by which a virtual machine currently in operation is switched to another virtual machine as a switching target;

a priority acquiring step of acquiring a priority of a task having a highest priority among executable tasks in the currently running virtual machine;

a priority setting step of setting the priority acquired in the priority acquiring step by the another virtual machine to a priority of the switching task;

a notifying step of notifying the priority acquired in the priority acquiring step and a switching indication to switch the virtual machine currently in operation to the another virtual machine in a case where the switching task is executed according to task scheduling by the operating system; and

a switching step of receiving the priority and the switching indication notified in the notifying step and switching the virtual machine currently in operation to the another virtual machine.

10. A computer readable recording medium storing a virtual machine control program for causing a computer to function as at least:

a plurality of virtual machines each having an operating system that carries out scheduling of tasks to be executed according to priorities of the tasks; and

a virtual machine control unit that controls switching of the plurality of virtual machines, wherein;

each of the plurality of virtual machines includes

a task execution unit that executes a switching task to perform switching processing by which a virtual machine currently in operation is switched to another virtual machine as a switching target,

a priority acquisition unit that acquires a priority of a task having a highest priority among executable tasks in the currently running virtual machine, and

a priority setting unit that sets the priority acquired by the priority acquisition unit of the another virtual machine to a priority of the switching task;

the task execution unit notifies the virtual machine control unit of the priority acquired by the priority acquisition unit and a switching indication to switch the virtual machine currently in operation to the another virtual machine in a case where the switching task is executed according to task scheduling by the operating system; and

the virtual machine control unit receives the priority and the switching indication notified by the task execution unit and switches the virtual machine currently in operation to the another virtual machine.