JPH02148155A - Input/output processing system - Google Patents

Abstract

PURPOSE:To efficiently operate a virtual computer system by directly executing an input/output (I/O) instruction on a virtual computer without taking it into consideration whether channel command word (CCW) executed on the virtual computer is related to the constitution of a real machine system or not. CONSTITUTION:A data processor to process the I/O instruction consists of an I/O privileged mode latch 1, a CCW register 2, a decoder 3, a discriminant circuit 4, an inhibit circuit 5, an I/O interrupt circuit 6, a bus selecting circuit 7, a multiplexer 8, and channels 9. The I/O instruction processing is directly executed on the virtual computer without taking it into consideration whether CCW which cannot be executed on the virtual computer is included or not. Thus, the virtual computer system is efficiently operated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an input/output processing method in a computer system, and particularly to an input/output processing method suitable for direct execution of input/output instructions (work instructions) in a virtual computer. Regarding.

[Conventional technology]

IO command processing in a computer system is described, for example, in Japanese Patent Laid-Open No. 47-26045.

An input/output operation is started by an IO start command such as a 5SCH command, a channel address word (CAW) is read from a fixed address in the main memory specified by the command, and the CAW is
Read channel command ff6 (cCW) from. CA
W points to the beginning of the CCW sequence to be executed, and one CCW
The CW controls the input/output operation of one block. By chaining the CCWs, input/output operations of multiple blocks are
This can be done with 5 SCH instructions. Conventionally, in the execution of this CCW, there was no distinction between privileged mode and non-privileged mode, and all CCWs were executed.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not give any consideration to direct execution of all IO instructions on a virtual machine.

Virtual machines generally operate in two modes: a guest mode in which a real computer directly executes the virtual machine's instruction sequence, and a host mode in which software simulates an instruction that cannot be directly executed if it appears in the virtual machine's instruction sequence. This is realized by the operating mode. Examples of instructions that cannot be directly executed on this virtual machine include instructions for manipulating the resources of the computer system and instructions for controlling interrupts.

By the way, CCW also includes commands for manipulating the resources of a computer system. An example of this is set channel path group ID. This command is a command for setting which path belongs to the same data processing device for an IO control device connected to multiple data processing devices in a data processing device that has a path selection and path reconnection function. It is. This set channel path group ID is used by the operating system (O8) when defining the configuration of the computer system.

If a CCW including this command is executed on a virtual machine, it will change the configuration of the real computer system.
A CCW sequence including this command cannot be directly executed on a virtual machine.

Generally, the above set channel path group I is applied to the CCW column activated by an IO start instruction such as a 5SCH instruction.
It is unclear whether D is included. Therefore, conventionally 5
The SCH instruction itself cannot be executed directly on a virtual machine; O8 determines whether it is running on a virtual machine, and if it is running on a virtual machine, sets, channels, paths, groups, etc. It was necessary to avoid issuing CCW strings containing IDs.

The purpose of the present invention is to enable direct execution of instructions on a virtual machine, and to configure a virtual machine system in which an O8 does not need to be aware of whether or not it is running on a virtual machine. It is in.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an IO privilege mode in a data processing device, and provides a
A CW etc. is defined as a privileged CCW that can be executed only in the IO privileged mode. Further, the setting of the IO privilege mode is determined by the mode of the data processing device at the time of issuing the ■○ instruction, and is held until the series of CCWs activated by the IO instruction is completed.

[For production]

When issuing all IO commands in host mode, IO privilege mode is turned ON. All CCWs are executed at this time. When an IO command is issued in guest mode, IO privileged mode is turned off. At this time.

Execution of privileged CCWs and the like related to the configuration of the computer system is suppressed, and the fact that the execution of the CCWs is suppressed is reported to software. The software simulates the CCW.

As a result, IO instruction processing can be directly executed on a virtual machine without considering whether or not a CCW that cannot be executed on a virtual machine is included.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. In the figure, 1 is an IO privilege mode latch, and 2 is a CCW register. 3
decodes the CCW's command and identifies the CCW as a privileged CC.
W (for example, a CCW related to configuration control such as a set channel path group ID). 4 is a determination circuit for determining whether the CCW is executable based on the outputs of the privileged mode latch 1 and the decoder 3; 5 is C according to the output of the judgment circuit 4.
A suppression circuit 6 is an IO interrupt circuit for reporting to software that the execution of the CCW has been suppressed. 7 is a path selection circuit, 8 is the output of the path selection circuit 7 and is output to CCW via an arbitrary channel.
9 is a channel.

The IO privilege mode latch 1 is set by the mode of the data processing device when an IO command such as the 5SC-H command is issued, and is held until the series of CCWs activated by the 5SC-H command are completed. When an IO command is issued in host mode, the IO privileged mode latch is set to '1'. Subsequently, the CCW is read from the main memory and set in the CCW register 2, and the decoder 3 converts the CCW into a privileged CCW. The output of the decoder 3 is ``1'' when it is privileged CCW, and is ``0'' otherwise. Enter the information and follow the instructions in Figure 2.

Determines whether the CCW set in CCW register 2 can be executed. That is, when the IO privilege mode latch 1 is "1", the determination circuit 4 determines that all CCWs are executable. At this time, the suppression circuit 5 does not operate, and the channel 9 is sent via the multiplexer 8 under the control of the path selection circuit 7.
CCW of CW register 2 is sent out.

On the other hand, in guest mode, IO privilege mode latch 1 is set to 140 I+. I in guest mode
Following the issuance of the O instruction, the CCW is read from the main memory and set in the CCW register 2. This CCW is decoded by the decoder 3 to determine whether it is a privileged CCW or not.
The decoded output of the decoder 3 is given to the determination circuit 4 together with the output of the IO privileged mode latch 1. As shown in FIG. 2, if the CCW is not a privileged CCW, the determination circuit 4 determines that it is executable, so execution of the CCW in the CCW register 2 is not inhibited. If the CCW is a privileged CCW, the 1 determination circuit 4 determines that it is not executable, so the inhibition circuit 5 operates and the execution of the CCW in the CCW register 2 is inhibited. Further, at this time, the output (unexecutable output) of the determination circuit 4 is simultaneously sent to the IO interrupt circuit 6, the IO interrupt circuit 6 operates, and an IO interrupt of a privileged CCW exception is generated.

Due to the IO interrupt of the privileged CCW exception, the software recognizes that the CCW cannot be directly executed on the virtual machine, and simulates the CCW.

With the configuration shown in Figure 1, in IO processing in guest mode, the CCW related to the configuration of the computer system is connected to a series of CCWs.
It is possible to execute an IO instruction without considering whether or not it exists in the queue, and it is possible to configure a virtual machine system where O8 does not need to consider whether it is running on a virtual machine or not. .

Note that in the above description, the setting of the IO privilege mode latch 1 is performed depending on the mode of the data processing device when the IO command is issued, but in general, it is not necessary to set the IO privilege mode latch 1 only when the IO command is issued.
The setting may be made by switching between host mode and guest mode of the data processing device.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, there is no need to consider whether or not the CCW executed on the virtual machine is related to the configuration of the real computer system.

Since IO instructions can be directly executed on the virtual machine, it is effective in increasing the efficiency of the virtual machine.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a diagram showing the operation of the determination circuit in FIG. 1. 1... IO privileged mode latch, 2... CCW register, 3... decoder, 4...
... Judgment circuit, 5... Suppression circuit, 6... IO interrupt circuit, 7... Path selection circuit, 8... Multiplexer, 9 channels.

Claims (2)

[Claims] (1) In a data processing device that processes input/output instructions (IO instructions), an IO privileged mode is provided, and when the IO privileged mode is ON, all channel command words (CCW) are executed, and when the IO privileged mode is OFF, all channel command words (CCW) are executed. At this time, only the CCW of a predetermined specific command is executed, and the CCW of other commands is executed.
W is an input/output processing method characterized by inhibiting execution and reporting to software that it cannot be executed. (2) Set the IO privilege mode when issuing the IO command,
2. The input/output processing method according to claim 1, wherein a series of CCW sequences activated by the IO instruction are held while being executed.