JPS59125450A - Virtual computer control system - Google Patents

Abstract

PURPOSE:To reduce the switching of virtual computers and to improve the use efficiency of an actual processor by indicating the continuation of the allocation of virtual computers. CONSTITUTION:A virtual computer switching control mechanism 2 decides a virtual computer to be allocated next in a switching opportunity of respective virtual computers. Then, the processor state of the virtual computer to which the actual processor is allocated so far is read out of a processor state register group 3 on the basis of the result of the decision and saved in a virtual computer control table 1 as saved information 14. Then, saved information 14 corresponding to a virtual computer to which the actual processor is allocated newly is fetched from the virtual computer control table 1. Then, it is stored in the processor state register group 3 of the actual processor to perform switching to the virtual computer. Further, the identification number VMID of the new virtual computer is set in a virtual computer identification number register 5 and the state of the virtual computer is updated into ''in execution''.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a virtual machine control method, and in particular, to a virtual machine control method for allocating processors and virtual machines in a virtual machine system.
This relates to the virtual machine+HII m method that performs tlJ #lI.

In general, a virtual computer system is a technology that virtually creates multiple δ4 computer systems on one computer system, and in this virtual computer system, a virtual processor in each virtual computer on the system Real processors are sequentially allocated to the real processors.

Therefore, the virtual machine can actually execute processing only when a real processor is assigned.

The following processing is required to switch the virtual machine, that is, to switch the assignment of the virtual processor on the virtual machine W to the real processor.

In other words, since the processor state of the virtual machine to which a real processor is currently assigned, i.e., which is currently being executed, is on the real processor, this is saved as the state of the virtual processor to the save area corresponding to the virtual machine (- 1. After this, the saved processor information of the virtual machine to which a new real processor is to be assigned, that is, the state of the virtual processor, is loaded onto the real processor, and the virtual machine becomes executable for the first time.

As described above, in a virtual computer system, a relatively large overhead is required when switching the assignment of virtual processors to real processors, so it is undesirable to unnecessarily increase the number of times the virtual machines are switched.

On the other hand, even if there is no process to be executed for a long time in a virtual computer, it is not desirable to allocate a real processor to the virtual computer from the viewpoint of effective utilization of the real processor.

Conventional virtual machine control methods include a virtual machine control table that stores time slice values for each virtual machine, and a process switching control mechanism that detects the idle state of the virtual machine running on a real processor and outputs an idle detection signal. a time slice timer that outputs a time slice signal t1 after a specified time indicated by the corresponding time slice value has elapsed since the real processor was allocated to the virtual machine; and the idle detection signal. The present invention includes a virtual hand W for determining and switching a virtual machine to be assigned to the real processor when NFC is supplied and when the time slice expiration signal is supplied, and a machine switching control mechanism.

In other words, in conventional virtual machine control methods, the method for switching virtual machines is to switch to another virtual machine when there is no more processing to be executed on the virtual machine, that is, when an idle state is detected. and,
Virtual needle! A method is known in which a real processor is assigned to a virtual machine at fixed intervals, regardless of whether there is a process to be executed on the machine.

However, the method of switching to another executable virtual machine upon detecting an idle state has the following drawbacks.

In other words, when multiple programs are being executed within - virtual machines, other programs can often be executed after waiting a short period of time; It is often not a good idea to switch computers. On the other hand, with a method that mechanically allocates a real processor to each virtual computer for a fixed period of time, it is difficult to switch computers when only a single program is running on the virtual computer. Once an input/output operation request is issued from a program on the virtual metering PA and this program enters the waiting state, the virtual metering machine remains in an idle state until the input/output operation is completed.

In other words, input/output operations are generally extremely slow compared to the processor's operating time, so assigning an extra processor to this virtual needle 4 will wastefully monopolize the real processor. .

That is, the conventional virtual needle cutter control method often has the drawbacks of large overhead and low utilization efficiency of the real processor.

An object of the present invention is to provide a virtual machine control method that can reduce overhead and improve the efficiency of using real processors.

That is, an object of the present invention has been made in view of the above points, and it is an object of the present invention to provide a virtual computer control method that reduces the switching of n virtual machines and increases the efficiency of using real processors.

That is, an object of the present invention is, for example, to set virtual machine switching as instruction information for a virtual machine running with a single program, and to set virtual machine switching as instruction information for a virtual machine running with multiple programs. By instructing continuation of allocation, the number of times virtual machines are switched is reduced, and the wasted time of real processors is also reduced.The virtual machine system reduces the overhead of switching virtual machines and makes effective use of real processors. The objective is to provide a virtual computer control method that can be implemented.

The virtual machine control method of the present invention includes a virtual machine control table that stores a time slice value and instruction information for switching or continuing for each virtual machine, and detects all idle states of the virtual machine running on a real processor. a process switching I11 control mechanism that outputs an idle detection signal when the real processor is allocated to the virtual machine, and outputs a time slice expiration signal after a specified time specified by the corresponding time slice value has elapsed since the virtual machine was assigned the real processor; a virtual time slice timer that should be re-allocated to the real processor when the idle detection signal is supplied, the corresponding instruction information instructs to continue, and when the time slice expiration signal is supplied. Decided on the calculator! The system includes a virtual machine switching control mechanism for increasing the number of computers.

In other words, the virtual computer control method of the present invention includes, in a virtual computer system that stores a plurality of virtual computers, a virtual computer switching control means that determines a virtual computer to be assigned to a real processor and switches the virtual computers based on this determination; a time slice timer that generates a time slice expiry signal to the virtual machine switching control means when a specified time has elapsed since the virtual machine was assigned a real processor; and a time slice timer that detects an idle state in the virtual machine running on the real processor. a virtual machine control table that stores state information of each virtual machine and save information as a processor state, as well as instruction information for specifying an operation when an idle state is detected; When an idle state is detected in a virtual machine that is being executed and has been assigned a real processor, the instruction information on the virtual machine control table corresponding to the virtual machine that has been assigned a real processor is referred to, and its contents are If the instruction information specifies switching according to the above, by activating the virtual machine switching control mechanism,
If the real processor is switched to another virtual machine and the instruction information specifies to continue, the allocation of the real processor to the other virtual machine is not switched and the time slice timer is generated. The virtual machine is configured to be switched in response to a time slice expiration signal.

In other words, the virtual machine control method of the present invention determines whether to switch virtual machines when an idle state of a running virtual machine is detected, or to continue assigning virtual machines until a certain period of time elapses without switching. The configuration is configured such that instruction information indicating whether the virtual machine should be used is maintained for each virtual machine, and when an idle state is detected in a virtual machine, switching to another virtual machine or continuation of the virtual machine is controlled according to this instruction information. be done.

Next, the configuration and operation of an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

In the virtual computer control method shown in FIG.

The virtual machine control table 1 has an entry corresponding to each virtual machine, and each entry includes status information 12 indicating whether the corresponding virtual machine is operable, and a time slice value 13a of the corresponding virtual machine. In addition to save information 14 which is the state of the processor at the time when the allocation of the real processor to the processor is cancelled, it is used to store instruction information 11 indicating the process to be performed when an idle state is detected.

When the value 1.1'' is set as the instruction information 11, it indicates that the virtual machine should be switched when an idle state is detected.
If the value 101 is set as instruction information 11, it indicates that even if an idle state is detected, the allocation should continue without switching the virtual machine and processing should continue. shall be.

In addition, at the time of switching each virtual machine, the virtual machine switching control mechanism 2 determines the next virtual machine to which a real processor should be assigned, and based on this decision, the virtual machine to which a real processor has been assigned until just before is switched. The processor state of the processor is read from the processor state register group 3, and saved as save information 14 in the virtual machine control table 1, and the save information 14 corresponding to the virtual machine to which a new real processor is to be assigned is saved in the virtual machine control table. Extracted from l, processor status register of real processor #
By storing the information in 3, virtual machines can also be switched. At the same time, the virtual machine identification number VMID indicating the virtual machine to which the real processor has been newly assigned is set in the virtual machine identification number register 5, and the state of the virtual machine is also updated to 1 during one execution.

At this time, the time slice timer 7 is also initialized. That is, the virtual machine switching control mechanism 2 uses the virtual machine identification number VMID on the virtual machine control table 1.
The time slice value 13 corresponding to the time slice value 13 is set in the time slice timer 7 by supplying the time slice value setting signal 72.

The time slice timer 7 is a timer that counts down based on a clock signal, and when a specified time elapses,
A time slice expiry signal 71 is generated and notified to the virtual machine switching control mechanism 2.

A time slice expiration signal 71 from the time slice timer 7 is applied to the virtual machine switching control mechanism 2, and is used as a trigger for switching the virtual machine. That is, when the time slice expires, the real processor is taken away from the virtual machine that has been occupied with the real processor, and allocated to another virtual machine that can execute the real processor.

However, in the embodiment shown in FIG. 1, all input/output operations generated by programs on the virtual machine are performed by firmware, and for this processing, the processor state of the running virtual machine is saved and input/output operations are performed by the firmware. It is said that there is no need for processing such as loading the operating environment of the disposable chopsticks program for processing the motion.

Namely, virtual needles! Input/output requests to virtual input/output devices issued by programs on the machine are processed by the firmware without saving the processor state of the virtual machine.
An input/output interrupt that is converted into an input/output request to the corresponding real device, executed, and applied to the real processor upon completion of the input/output is also processed by the firmware as a virtual input/output request without saving the state of the virtual machine. This is converted into an input/output interrupt for the machine and is also reflected in the state of the virtual machine. That is, a process is performed to change the state of the virtual machine to an executable state, and it is also used as a trigger for switching the virtual machine.

The virtual machine switching control mechanism 2 started with this opportunity will allocate a real processor to this virtual machine if there is no other executable virtual machine.

Furthermore, as a matter of course, the virtual machine switching control mechanism 2 itself is realized by hardware or firmware, and there is no need to use the real processor provided to the virtual machine for this to operate.

Furthermore, the process switching control mechanism 4 controls the allocation of processors to each process within the virtual machine.
When there are no more executable processes within the virtual machine,
That is, when the processor becomes idle within the virtual machine, this is detected and the idle detection signal 41 is output. This idle detection signal 41 is applied to one input of the AND gate 6, and the instruction information 11 from the virtual machine n machine control table l is applied to the other input. 'J4. The voltage is applied to the machine switching control mechanism 2.

Now, when a certain virtual machine is being executed (the value of the instruction information 11 stored in the virtual machine control table l which is stored here and addressed by this virtual machine identification number VMID) is applied to the AND gate 6. ) When the process switching control mechanism 4 detects an idle state and outputs an idle detection signal 41, this idle detection signal 41 is applied to the AND gate 6.

At this time, when the instruction information 11 of the entry corresponding to the running virtual machine among the instruction information 11 stored in the virtual machine control table 1 has a value of 111, that is, when the virtual machine is switched when an idle state is detected, If so, the AND gate 6 outputs the value 111f;r as the virtual machine switching signal 61, thereby causing the virtual machine switching controller! 2 is activated.

The activated virtual machine switching control mechanism 2 changes the state of the virtual machine to which the real processor is currently allocated to the waiting state.

Next, the status information 12 of the virtual machine control table 1 is searched 7 to determine an executable virtual machine.

After this, the processor state of the virtual machine to which the real processor has been assigned so far is saved as the save information 14 in the virtual machine control table 1, and then the saved information 14 of the determined virtual machine is returned to the real processor. Finally, the switch to the selected virtual machine is completed.

When the process switching control mechanism 4 detects an idle state, the instruction information 11 corresponding to the virtual machine that is being executed, that is, to which a real processor has been assigned in the virtual machine control table 1, instructs to continue the virtual machine assignment. )", the fl@ of the corresponding instruction information 11 is 1.
Since the computer game)6ii''(J'; This means that machine n waits for the idle state to be released until the real processor is assigned υ'!.

If the instruction information 11 instructs the continuation of the @If calculation (8), this virtual computer can take over the real processor only if it is assigned to this virtual computer. The tight slice timer 7 is set when the tight slice value 13 is consumed, i.e., when the Oi idea calculator is assigned the processor.
This is limited to when the timeout signal 71 is generated, or when this virtual machine, p1, which has a high priority, becomes executable.

The embodiments of the present invention have been described above, but as is clear from the above description, the gist of the present invention is to determine a virtual machine to be assigned to a real processor in a virtual computer system that implements a plurality of virtual machines, and a virtual computer switching control means for switching virtual computers based on this determination.

After the virtual machine is assigned a real processor,
a time slice timer that generates a virtual machine switching signal to the virtual machine switching control means when a specified time has elapsed; a process switching control means that detects an idle state in a virtual machine running on a real processor; In addition to storing state information and save information as the processor state, it also has a virtual machine control table that stores instruction information for specifying operations when an idle state is detected. When an idle state is detected in a computer, the instruction information on the virtual machine control table corresponding to the virtual computer to which a real processor is assigned is referred to, and the instruction information specifies switching according to the contents. In this case, the real processor is switched to another virtual machine by activating the virtual machine switching control mechanism,
If the instruction information specifies continuation, do not switch the allocation of the real processor to another virtual machine, but switch the virtual machine using the time slice expiration signal generated by the time slice timer as a trigger. According to
The purpose of the present invention is to realize a virtual machine switching control method that reduces the overhead of virtual machine switching and also increases the efficiency of using real processors. Since it is unrelated, it is omitted to simplify the explanation, but it will be obvious to those skilled in the art that it can be realized in any number of ways.

The virtual machine control method of the present invention stores instruction information in the virtual machine control table, so that even if an idle state is detected, if the instruction information instructs to continue, the virtual machine will not be switched. As a result, the number of times virtual machines are switched can be reduced, which has the effect of reducing overhead and improving the efficiency of using real processors.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. 1...Virtual computer control table, 2...
- Virtual machine switching control mechanism, 3... Processor status register, 4... Process switching control mechanism,
5...Virtual machine identification number register, 6...
...and gate, 7...time slice timer, 11...instruction information, 12...state information, 13...time slice value, 14.・・・・・・
- Evacuation information, 41...Idle detection signal, 61
. . . Virtual needle n machine switching signal, 71.° . . . ° Time slice end signal, 72 . . . Time slice value setting signal.

Claims (1)

[Claims] A virtual machine control table that stores a time slice value and instruction information for instructing whether to switch or continue for each virtual machine, and a process switch that detects an idle state in the virtual machine running on a real processor and outputs an idle detection signal. a control mechanism; a time slice timer that outputs a time slice expiration signal after a specified time indicated by the corresponding time slice value has elapsed since the real processor was allocated to the virtual computer; A virtual computer for determining and switching a virtual computer to be allocated to the real processor when the corresponding instruction information instructs to continue and when the time slice expiry signal is supplied. A virtual computer control method comprising: a switching control mechanism.