JPH07225694A - Virtual computer system - Google Patents

Abstract

PURPOSE:To provide a virtual computer system capable of smoothly performing a processing even when the same peripheral equipment is alternately utilized from plural OSes. CONSTITUTION:A virtual computer 1 is provided with a table 14 for storing the state of the peripheral equipment 4 controlled by a real device controller 3 and the state of the peripheral equipment controlled by a quest device driver 6. Then, by monitoring the respective device drivers 3 and 6 accessing the peripheral equipment 4 by the virtual machine monitor 1, checking the table 14 for storing the states of the peripheral equipment and permitting access only when conditions are valid, the access of the peripheral equipment by the plural OSes is smoothly performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a virtual computer which uses a plurality of different OSs on one real computer, and more particularly,
The service of the parent OS can be used directly from the application on the guest OS.
The present invention relates to a virtual computer system capable of efficiently controlling peripheral devices of a real computer.

[0002]

2. Description of the Related Art In a virtual computer system in which a plurality of OSs are operated at the same time, it is usual to prevent the hardware of a real computer from simultaneously issuing input / output requests from two or more OSs. For example, JP-A-3-131
In Japanese Patent Publication No. 936, a table for managing access to an input / output device by a guest OS is provided in a virtual machine monitor so that requests from two or more OSs to the input / output device do not occur at the same time. There is.

However, in the conventional method, when the application on the guest OS needs to alternately use the access to the peripheral device by the service of the parent OS and the access to the peripheral device by the service of the guest OS, There is a possibility that each OS may not be able to perform processing smoothly because each OS cannot access another OS until the OS starts using the peripheral device and finishes and releases the processing.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to enable a plurality of OSs to be operated at the same time, and to use a guest OS service and a parent OS service alternately from an application on the guest OS to provide one peripheral device. It is to provide a virtual computer system that enables smooth use of peripheral devices even when accessed.

[0005]

In order to solve the above-mentioned problems, according to the present invention, a parent OS for controlling a real computer and the parent O
A virtual machine monitor that monitors the operation of S, and one or more guest OSs that operate under the control of the virtual machine monitor
In the virtual machine system consisting of applications operating on the guest OS, an interface is provided so that the application on the guest OS can directly use the function of the parent OS. Also, the parent O that controls the actual computer
S, a virtual machine monitor for monitoring the operation of the parent OS,
An interface that allows a function of the guest OS to be directly used by an application on the parent OS in a virtual computer system including one or more guest OSs that operate under the control of the virtual machine monitor and an application that runs on the parent OS To provide. Further, a parent OS that controls the real computer, a real device handler that controls the peripheral device, a virtual computer monitor that monitors the operation of the parent OS, and one or more units that operate under the control of the virtual computer monitor. In a virtual computer system including a guest OS, a guest device driver that controls a peripheral device of a real computer from the guest OS, and an application that operates in the guest OS,
The virtual computer monitor is provided with a table for storing the state of the peripheral device controlled by the real device controller and the state of the peripheral device controlled by the guest device drive, and the contents of the table are monitored to operate the actual peripheral device. The means to do is provided.

[0006]

A parent OS that controls a real computer, a virtual computer monitor that monitors the operation of the parent OS, one or more guest OSs that operate under the control of the virtual computer monitor, and a guest OS that operates. In a virtual machine system including applications, a specific interrupt is generated from an application on a guest OS, and control is transferred to a virtual machine monitor. When a specific interrupt occurs, the virtual machine monitor activates the parent OS, requests the service of the parent OS, and executes the service. By returning to the guest OS after the service of the parent OS ends, the guest O
The application on S can directly use the function of the parent OS.

A parent OS that controls the real computer, a virtual computer monitor that monitors the operation of the parent OS, and one or more guest OSs that operate under the control of the virtual computer monitor
Then, in the virtual computer system composed of the application operating on the parent OS, the control is transferred to the virtual computer monitor by generating a specific interrupt from the application on the parent OS. When a specific interrupt occurs, the virtual machine monitor activates the guest OS and
Request the service of and perform the service. Guest OS
By returning to the parent OS after the above service is finished, the function of the guest OS can be directly used from the application on the parent OS.

[0008] Further, access from the application on the guest OS to the peripheral device through the parent OS and the guest OS
Even if you access the peripherals through
The virtual machine monitor is provided with a table that stores the state of the peripheral devices controlled by the real device controller and the state of the peripheral devices controlled by the guest device driver, and the virtual machine monitor allows each device drive to access the peripheral device. By monitoring and checking the table storing the state of the peripheral device when either device driver accesses the peripheral device, and permitting access to the peripheral device only when the condition is satisfied, a plurality of OSs can be obtained. To enable smooth access to peripheral devices.

[0009]

1 is a block diagram of an embodiment of the present invention.
In the figure, component 1 is a virtual computer monitor, 2 is a parent OS, 3
Is a real device driver, 4 is a peripheral device of a real computer, 5 is a guest OS, 6 is a guest device driver, 7 is a guest OS application, 11 is hardware access from the real device driver, and 12 is hardware from the guest device driver. Access to clothing, 13 is guest O
A parent OS is called from the S application, 14 is a state management table of peripheral devices in the virtual machine monitor, and 15 is a system timer.

FIG. 2 is a flow chart showing the operation of the present invention. In the figure, the numbers 200 to 215 indicate the processing contents.

The virtual machine monitor 1 has a higher privilege than the parent OS 2 and the guest OS 5 and monitors the operation of each OS. When booting, first boot the parent OS. It is assumed that the parent OS does not support the high privilege level supervisor mode. After booting the parent OS, the program of the virtual machine is started by the parent OS. The virtual machine program itself uses the supervisor mode, so the virtual machine monitor 1
Can have a higher privilege level than the parent OS. Note that the following description will be continued assuming that the guest OS also does not use the supervisor mode. Virtual machine monitor 1 is CP
Access to peripheral devices is detected by monitoring I / O access from U. In addition, a call from the application to the OS is detected by monitoring the software interrupt. Further, the virtual machine monitor detects an interrupt from a peripheral device by monitoring a hardware interrupt.

The parent OS 2 is an original OS designed to use a real computer having the peripheral device 4, and the peripheral device 4 is controlled by a program called a real device driver 3. The arrow 11 indicates the peripheral device 4 by the actual device driver.
Indicates access to. The access 11 is monitored by the virtual machine monitor as described above.

The guest OS 5 is an OS created for the hardware different from the hardware for the parent OS 2, and can run the guest OS application 7. The guest OS 5 accesses the peripheral device 4 by the guest device driver 6. Here, it is assumed that the guest device driver 6 is made to be able to control the peripheral device 4.

Originally, in order to operate the guest OS application 7 on a real computer having the peripheral device 4, it is necessary to remake the application 7 for the parent OS. However, when the scale of the application 7 is large, the time and effort for changing the application 7 becomes very large. Therefore, the virtual computer monitor 1 is operated on the real computer having the peripheral device 4, and the guest OS 5 and the guest O are managed under the control of the virtual computer monitor 1.
By using the application for S5, it is possible to use the application 7 on different hardware.

When the computer hardware is different, the memory map is often different. So virtual computer monitor 1
Has a function of realizing a memory map for operating the guest OS 5 and the guest OS application 7.

First, the operation when the guest OS application 7 requests a service from the guest OS 5 will be described. The guest OS application 7 requests the service of the OS to the guest OS 5 in the form of software interrupt. The services of the OS include, for example, a read / write request to an external storage device and an input / output request to an input / output device.

When the software interrupt instruction is executed in process 200, the virtual machine monitor 1 is started in process 201. The virtual machine monitor 1 determines the type of interrupt, and if it is a service request to the guest OS 5, the control is transferred to the interrupt processing routine of the guest OS 5 in process 202. The guest OS 5 uses the guest device driver 6 of step 203 to access the peripheral device 4 and execute the service. After the service ends, in step 205, the guest OS 5 returns to the guest OS application 7.

Next, a case where the guest OS application 7 requests the service of the parent OS 2 will be described. In process 200, the guest OS application 7 requests an OS service in the form of a software interrupt. When the software interrupt instruction is executed, the virtual machine monitor 1 is activated in step 201. The virtual machine monitor 1 determines the type of interrupt. Here, a specific interrupt number is determined in advance, and in the case of the specific interrupt number, it is understood that the interrupt requests the service of the parent OS 2. When an interrupt occurs and the request is a service request to the parent OS2, the virtual machine monitor 1 first executes the interrupt processing routine of the parent OS2 in the process 212, and then the operable memory map of the parent OS2 is first executed. After setting, the control is transferred to the interrupt processing routine of the parent OS2. In step 213, the parent OS 2 accesses the peripheral device 4 by using the real device driver 3 and executes the service. After the service ends, a program for calling the virtual computer monitor 1 is executed to transfer control to the virtual computer monitor 1. Here, the instruction to return from the interrupt process may be monitored by the virtual machine monitor 1 to detect the end of the interrupt process. The virtual machine monitor 1 sets the memory map executable by the guest OS 2 and then returns to the guest OS application 7.

With the above method, the service of the parent OS 2 can be received from the guest OS application 7. The advantage of this method is that even if the file structure of the floppy disk used in the guest OS 5 and the file structure of the floppy disk used in the parent OS are different, the floppy disk for the guest OS is inserted in one disk drive and the other floppy disk is used. Parent OS for disk drive
It is possible to insert a floppy disk for use and allow the application 7 of the guest OS to freely access the floppy disk having both data structures to read and write data and files.

Next, problems and solutions for accessing one peripheral device by two or more different OSs and device drives will be described. As a general method, when one OS accesses a peripheral device, another OS normally prohibits access to the peripheral device, which is called exclusive control.
However, in peripheral devices such as a floppy disk and a hard disk that read / write data by rotating a medium with a motor, the motor is often kept rotating for several seconds to several minutes even after the reading / writing of data is completed. This requires a certain amount of time to start and stop the motor, so once the floppy disk has been accessed and the motor has been spun, leave it in the spun state for a while and then move it to the floppy disk. In many systems, the motor is stopped to reduce power consumption and prevent mechanical wear of the disk drive only when access is not made within a certain period. When the start and stop of the motor are controlled by software by the device driver, a problem may occur.

In the real computer system of this embodiment, the system timer 15 controls the floppy disk motor. When the device driver 3 reads and writes a floppy disk, the device driver 3 first sets a counter in the work area of the device driver 3 to a specific value and then activates the floppy disk motor. It takes a certain amount of time to start the motor, so wait for the time before reading / writing the floppy disk.

Next, when reading and writing the floppy disk, the state of the motor is detected, and when the motor is in the off state, the counter is set and then the motor is started to perform reading and writing. Also, when the motor is rotating, the counter can be set to a constant value and reading and writing can be performed immediately.

The motor is stopped by a system timer interrupt. A system timer 15 is provided in the peripheral device 4 of the real computer, and a system timer interrupt is generated at a rate of several tens of times per second. In the case of a real computer, when a system timer interrupt occurs, control is transferred to the system timer interrupt processing routine of the parent OS and the system timer processing is performed. When the floppy disk motor is controlled by the system timer interrupt, the value of the motor control counter is first decremented by 1 in the system timer interrupt processing routine. If it reaches 0, stop the motor. Here, if the system timer occurs 20 times per second, or if it is desired to stop the floppy disk motor when there is no access for 10 seconds, the device driver may set the initial value of the counter to 200.

When the guest OS 5 accesses the floppy disk, the control is performed in substantially the same sequence as the parent OS.

Here, the parent O is assigned to one disk drive.
Set the floppy disk with the file structure of S2,
A floppy disk having the file structure of the guest OS is set in another disk drive, and the guest OS 5 and the parent OS are alternated from the guest OS application 7.
Consider the case of accessing both floppy disks using the second service. Here, the guest device driver 6 and the real device driver 3 each have a counter for motor control prepared therein, and the system timer 15
When an interrupt is received from the virtual machine monitor, the virtual machine monitor performs both the interrupt processing routine on the guest OS 5 side and the interrupt processing routine on the parent OS 2 side. Further, the motors of the disk drives are controlled to start and stop at the same time for all the drives.

The application 7 for the guest OS is the parent O
When the floppy disk having the file structure of the guest OS 5 set in another disk drive by the guest OS 5 is accessed after the reading and writing of the floppy disk having the file structure of the parent OS 2 by S 2, the floppy disk by the parent OS 2 is accessed. Shortly after the disk is accessed, the interrupt processing routine by the system timer 15 may forcibly stop the motor even though the guest OS 5 is using the floppy disk.

The above-mentioned problem is that the virtual computer monitor is provided with a table for holding the states of the motors by both OSs,
When the device driver of either OS tries to stop the motor, the contents of the above table are checked, and the motor is actually stopped only when the motor is stopped by the device driver of any OS. Can be solved by doing.

The virtual machine monitor 1 has a management table 14 inside, and further monitors the access 11 from the real device driver 3 to the peripheral device 4 and the access 12 from the guest device driver 6 to the peripheral device 4. This is realized by the CPU utilizing the function of detecting access to a specific I / O port.

I / for controlling the floppy disk motor
When there is access to the O port, the virtual computer monitor 1 is called, and when the motor is started, the management table 14 is set with information about which OS used to start the motor. In order to know from which OS the I / O port is accessed, there is a method of providing a flag for identifying the OS currently operating and managing the flag by the virtual 86 monitor. Further, it is possible to identify which OS is being executed by checking the address where the program being executed at the time of accessing the I / O port is located.

By the timer interruption by the system timer 15, the virtual machine monitor 1 is caused to perform both the interruption processing routine of the guest OS 5 and the interruption processing routine of the parent OS 2. The motor is stopped when the system timer 15 generates a timer interrupt and the interrupt processing routine depresses the counter so that the value of the counter becomes zero. When the interrupt processing routine accesses the I / O port and tries to stop the motor, the virtual computer monitor detects it and sets in the management table 14 which OS the motor will be in the stopped state. Next, the state of the motor by another OS is checked, and only when it is confirmed that the state of the motor is in the stopped state in all the OSs, the I / O port is actually accessed to bring the motor into the stopped state. In addition, other OS
If at least one of the motors is in the rotating state, the table 14 is only set and the I / O port is not actually accessed.

The present invention can be applied not only to an external storage device, but also to a system in which the computer itself shuts off the power of the computer by a relay. For example, if the power is cut off from the guest OS 5 while the parent OS 2 is operating, a system failure may occur. However, in the virtual computer monitor 1,
It is possible to avoid the occurrence of a failure by preparing a flag having a power-off status of each OS and turning off the power of the real computer only when the power is turned off in all OSs.

FIG. 3 is a block diagram of an embodiment of the present invention. In the figure, components 1 to 15 are the same as the components in FIG. Reference numeral 307 is a parent OS application, and 313 is a call of the guest OS from the parent OS application.

Normally, the application of the parent OS rarely needs the service of the guest OS, but the parent O
If the development environment of S is better than that of the guest OS, it is possible to develop software for supporting the application of the guest OS on the parent OS. For example,
When reading and writing the floppy disk for the guest OS is required, the guest OS is moved from the moving application on the parent OS.
There are cases where you want to use the service of.

In that case, a means for requesting the service of the guest OS from the application of the parent OS is required. Next, the parent OS application 307 is the guest O
The case of requesting the service of S5 will be described. The parent OS application 307 requests OS services in the form of software interrupts. When the software interrupt instruction is executed, the virtual machine monitor 1 is activated. The virtual machine monitor 1 determines the type of interrupt. Here, a specific interrupt number is determined in advance, and in the case of the specific interrupt number, it is understood that the interrupt requests the service of the guest OS 5. An interrupt occurs, and that is the guest OS
In the case of a service request to the guest OS 5, the virtual machine monitor 1 first sets an operable memory map of the guest OS 5 in order to execute the interrupt processing routine of the guest OS 5, and then the guest OS 5 executes the interrupt processing routine. Transfer control. The guest OS 5 uses the guest device driver 6 to access the peripheral device 4 and execute the service. After the service ends, a program for calling the virtual computer monitor 1 is executed to transfer control to the virtual computer monitor 1. Here, the instruction to return from the interrupt process may be monitored by the virtual machine monitor 1 to detect the end of the interrupt process. The virtual machine monitor 1 sets the memory map executable by the parent OS 2 and then returns to the parent OS application 307.

With the above method, the service of the guest OS 5 can be received from the parent OS application 307. The advantage of this method is that even if the file structure of the floppy disk used in the parent OS2 and the file structure of the floppy disk used in the guest OS5 are different, the floppy disk for the guest OS is inserted in one disk drive and the other floppy disk is used. This is because a floppy disk for the parent OS is inserted in the disk drive, and the application 2 of the parent OS can freely access the floppy disk having both data structures to read and write data and files. .

[0036]

According to the present invention, a parent OS that controls a real computer, a virtual computer monitor that monitors the operation of the parent OS, and one or more guests that operate under the control of the virtual computer monitor In a virtual computer system consisting of an OS and an application running on the guest OS, the guest OS
By generating a specific interrupt from the above application, control is transferred to the virtual machine monitor, and the parent O
Start S to perform the service of the parent OS. By returning to the guest OS after the service of the parent OS ends, the application of the guest OS can directly use the function of the parent OS.

A parent OS that controls the real computer, a virtual computer monitor that monitors the operation of the parent OS, and one or more guest OSs that operate under the control of the virtual computer monitor
In a virtual machine system including an application running on the parent OS, a specific interrupt is generated from the application on the parent OS so that control is transferred to the virtual machine monitor, and the guest OS is started to start the guest OS. Get the service done. By returning to the parent OS after the service of the guest OS is terminated, the function of the guest OS can be directly used by the application on the parent OS.

Furthermore, the access of the peripheral device from the application on the guest OS through the parent OS and the guest OS
Even if you access the peripherals through
The virtual machine monitor is provided with a table that stores the status of the peripheral devices controlled by the real device controller and the status of the peripheral devices controlled by the guest device driver, and the virtual machine monitor allows each device driver to access the peripheral device. By monitoring and checking the table storing the state of the peripheral device when either device driver accesses the peripheral device, and permitting access to the peripheral device only when the condition is satisfied, a plurality of OSs can be obtained. The peripheral device can be smoothly accessed by.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of processing contents.

FIG. 3 is a configuration diagram showing an embodiment of the present invention.

[Explanation of symbols]

 1 ... Virtual machine monitor, 2 ... Parent OS, 3 ... Real device driver, 4 ... Peripheral device, 5 ... Guest OS, 6 ... Guest device driver, 7 ... Guest OS application, 11 ... Access by real device driver, 12 ... Access by guest device driver, 13 ... Interface to parent OS, 14 ... Management table, 200-215 ... Processing content, 307 ... Parent OS application, 313 ... Interface to guest OS.

Claims (3)

[Claims] 1. A parent OS that controls a real computer, a virtual computer monitor that monitors the operation of the parent OS, one or more guest OSs that operate under the control of the virtual computer monitor, and a guest OS. A virtual computer system comprising an operating application and having an interface that allows an application on a guest OS to directly use a function of a parent OS. 2. A parent OS that controls a real computer, a virtual computer monitor that monitors the operation of the parent OS, one or more guest OSs that operate under the control of the virtual computer monitor, and a parent OS. A virtual computer system comprising an operating application and having an interface that allows an application on a parent OS to directly use the functions of the guest OS. 3. A parent OS for controlling a real computer, a real device handler for controlling peripheral devices, a virtual computer monitor for monitoring the operation of the parent OS, and one operating under the control of the virtual computer monitor. One or more guest OS, a guest device driver that controls the peripheral device of the real computer from the guest OS, and an application that runs on the guest OS,
The virtual computer monitor is provided with a table that stores the state of the peripheral device controlled by the real device controller and the state of the peripheral device controlled by the guest device driver, and the contents of the table are monitored to operate the actual peripheral device. A virtual computer system comprising means for performing.