JPH02208739A - Control method for virtual computer system - Google Patents

Abstract

PURPOSE:To positively generate a contention generated at the time of multiprocessor by a virtual computer by switching the virtual computer, whenever a GATE instruction is executed. CONSTITUTION:A GATE instruction control part 6 simulates an (a)-4 instruction, and thereafter, a fact that a GATE instruction is executed is informed to a virtual computer schedule part 7, and the virtual computer schedule part 7 allocates resources of a real computer to a virtual computer 3-2 being different from a virtual computer 3-1 which executes the instruction until immediately before. When a GATE instruction (b)-3 is executed, the control is shifted to a VM use privileged instruction simulation 7. A VM use privileged instruction control part 6 simulates the (b)-3-instruction, and thereafter, a fact that the GATE instruction is executed is informed to the virtual computer schedule part 7, and the virtual computer schedule part 7 allocates the real computer to the virtual computer 3-1 being different from the virtual computer 3-2 which executes the instruction until immediately before. In such a way, whenever the GATE instruction is executed, the virtual computers are switched. Accordingly, a contention generated at the time of multi-processor can be generated by the virtual computer.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a control method for a virtual computer system, and in particular, to a method for controlling a virtual computer system.
The present invention relates to a control method for a virtual computer monitor that simulates a tightly coupled multiprocessor virtual computer on a real computer consisting of two CPUs.

[Conventional technology] In general, in a virtual computer system, one CPU
When trying to simulate a tightly-coupled multiprocessor using a virtual computer system, it is often not possible to sufficiently check the operation of the virtual computer system.

In the case of a tightly coupled multiprocessor, a GATE control instruction is used for exclusive control of the shared memory, but its operation cannot be confirmed sufficiently in some cases.

An example of this will be explained using FIG.

FIG. 3 shows the instruction execution sequences of processors a and b when two CPUs are configured as a tightly coupled multiprocessor.

The a processors are a-1, a-2, a-3, a-4, .
・a -n -a -s Na -xb processor is b
-1, b-2, -, b-X are executed.

If there is a possibility that a processing conflict may occur when processors a and b perform simultaneous reference and execution of the same memory, exclusive control of the processors is implemented to guarantee the processing. The GATE control command is used for this purpose.

Assume that this exists in lock processing instructions a-4, b-4 and unlock processing instructions a-x, b-x of the GATE control command. Therefore, a-4 to a-X section (hereinafter referred to as A section) and b-4 to b
-x interval (hereinafter referred to as B interval) operates exclusively.

Now, if the b-4 and b-x instructions are missing due to a program defect, in a tightly coupled multiprocessor made up of real computers, another processor will run in the B section while the A section is running, resulting in an exclusive The section that should be run exclusively is no longer run, causing the program to malfunction.

However, in a virtual computer system realized by a real computer consisting of one CPU, even though multiple virtual computers are logically realized, the actual CPU is one, so the A section is one processor. , and then Section B often runs. Therefore, program failures that may occur on a real computer often do not occur on a virtual computer system.

[Problems to be Solved by the Invention] Therefore, as described above, in the virtual computer system of the conventional technology, the lock processing section is run through on the real CPU without being affected by another virtual computer, so exclusive control is not possible. The drawback is that malfunctions that would occur on a real computer due to the lack of instructions do not occur on a virtual computer.

Therefore, in view of the above drawbacks, the technical problem of the present invention is to
An object of the present invention is to provide a control method for a virtual machine that can actively switch virtual machines when executing a TE instruction.

[Means for Solving the Problems] According to the present invention, in a control method for a virtual computer system consisting of a virtual computer monitor that realizes a tightly coupled multiprocessor in a real computer consisting of one CPU, the virtual computer A means is provided for transferring control of an operating system or a program running on the virtual machine to the virtual machine monitor each time a CPU occupancy control instruction is executed, and the virtual machine monitor actively controls the virtual machine being executed by the virtual machine monitor. A control method for a virtual computer system is obtained, which is characterized in that the virtual computer system switches to

[Example] Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, where 1 is a CP
U (central processing unit), 2 is a main storage device.

A VMM (virtual machine monitor) 3 is stored in the main storage device 2, and two VMs (virtual machines) 4-1 and 4-2, which are simulated by the VMM 3, are operating in the VMM3.

In addition, the VMM 3 includes a VM privileged instruction simulation unit 5, a GATE instruction control unit 6, a VM schedule unit (virtual machine schedule unit) 7, and a VM privileged instruction communication unit (virtual machine There is a privileged command communication department) 8.

The two virtual machines VM4-1.4-2 constitute a tightly coupled multiprocessor, on which the operating system 9 runs.

In the virtual computer system, first, the VMM3 is initialized. At that time, the VM privileged command communication unit 8 communicates with the central processing unit 1
In order to realize a virtual computer system, the instruction that must be simulated is notified to the VM (hereinafter referred to as a VM privileged instruction). Among the VM privileged instructions, there is GATE, which is usually considered unnecessary for virtual machine systems.
The control command is notified as a VM privileged command.

The GATE control instruction is a special instruction that allows the central processing unit to perform a comparison instruction and a storage operation in memory in one instruction, and is usually used for tightly coupled multiprocessor 7ATEvJa. Ru.

Here, GATE control means that multiple central processing units are connected to one MEM, such as in a tightly coupled multiprocessor.
When one central processing unit shares a main memory (main memory), one central processing unit can avoid external disturbances caused by the other central processing unit during execution, causing inconsistencies in operation. If there is a possibility of giving, lock the process and
This is a mechanism to prevent other central processing units from being disturbed.

Further, the selection of the VM privileged instruction is built into the central processing unit from the beginning, and by changing the operation mode of the central processing unit, an interrupt operation may be executed when the VM privileged instruction is executed. In this case, when designing the central processing unit, the VM
It is necessary to include the GATE instruction among the privileged instructions.

The VM privileged instruction simulation unit 5 is a part that is executed via an interrupt or directly when an instruction notified to the central processing unit 1 by the VM privileged instruction notification unit 8 is executed, and in particular, the GATE instruction is executed. When this is executed, the GATE command control unit 6 operates. The virtual machine scheduler 7 determines the operating order of the virtual machines and executes operations for allocating central processing units to real computers.

The operation of the embodiment of the present invention will be explained using the flow shown in FIG.

Now, the virtual machine 3-1 has instructions a-1, a-2゜8-3
．． ···Running. a-4 is a GATE control command.

When a-4 is executed, the VM privileged instruction simulation unit 5
control is transferred.

The VM privileged instruction control unit determines the instruction type of the a-4 step, and since it is a GATE instruction, the GATE instruction control unit 6 executes it.

The GATE instruction control unit 6 simulates the a-4 instruction. Thereafter, the execution of the GATE instruction is notified to the virtual machine scheduler 7, and the virtual machine scheduler 7 allocates resources to the large computer, which is a virtual machine 3-21 that is different from the virtual machine 3-1 that was being executed until just before. assign. In the virtual machine 3-2, steps b-1, b-2, b-3L
, step b-3 is the GATE control command.

When b-3 is executed, control is transferred to the VM privileged instruction simulation 7.

The VM privileged instruction control unit 6 simulates the b-3 instruction. After that, the execution of the GATE instruction is notified to the virtual machine schedule unit 7, and the virtual machine schedule unit 7 transfers the real computer to the virtual machine 3-1, which is different from the virtual machine 3-2 that was being executed just before. assign. As a result, the virtual machine 3-1 executes instructions a-5, a-6, . . . .

By performing the above control, it is possible to switch the virtual machine in a negative manner when executing the GATE instruction.

[Effects of the Invention] As explained above, virtual machines can be switched each time a GATE instruction is executed, and there is an effect that conflicts that occur when multiprocessors are used in virtual machines can be actively caused.

Computer monitor, 4-1.4-2...Virtual computer running on a virtual machine, 5...V in virtual computer monitor
Privileged instruction simulating unit for M, 6... GATE instruction control unit in the virtual machine monitor, 7... Virtual machine schedule unit in the virtual machine monitor, 8... Privileged instruction notification unit for VM in the virtual machine monitor, 9. ...Virtual computer 4-1.
Operating system running on 4-2.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of the present invention, FIG. 2 is a flowchart showing the operation of the present invention, and FIG. 3 is a flowchart showing the operation of the prior art. 1...Central processing unit, 2...Main storage device, 3...
Virtual Figure 1 Figure 3

Claims (1)

[Scope of Claims] 1) A control method for a virtual computer system comprising a virtual computer monitor realizing a tightly coupled multiprocessor virtual computer, comprising: controlling an operating system or program running on the virtual computer; A control method for a virtual computer system, characterized in that a means for transferring control to the virtual computer monitor is provided each time a CPU occupancy control instruction is executed, and the virtual computer to be executed by the virtual computer monitor is actively switched. .