JPH0464095B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] This is a control method for recording program events in a virtual machine. In a virtual machine, the fact that there is a general-purpose register update record designation is memorized when moving to a monitor program, and in that case, when a general-purpose register is updated during monitoring, the fact that the update has occurred is memorized. When returning to the virtual machine with the updated display displayed, a predetermined interrupt is generated. With the above configuration, there is no need to simulate program event recording control using the monitor program, and control efficiency is improved.

[Industrial application field]

The present invention relates to a method for controlling program event recording of a virtual machine in a computer.

In computers, methods for controlling one or more other virtual computer systems, so-called virtual computers, are well known.

In that case, each virtual machine uses a monitor program (hereinafter referred to as
A virtual machine that is under the control of a virtual machine (referred to as a VM monitor) and to which control is handed over by the VM monitor is executed on the central processing unit of the real machine.

In a virtual machine, the operating system of the virtual system performs system management of the virtual machine, but the VM monitor intervenes in cases where the results of its control may affect other virtual machines. It is necessary to maintain the integrity of the entire actual computer system by

However, such intervention generally increases control overhead and tends to be a factor in degrading the performance of the virtual machine.

[Problems to be solved by conventional technology and invention]

FIG. 2 is a block diagram showing an example of the configuration of a computer system.

The central processing unit 1 executes the program of the VM monitor 3 on the main storage device 2 and operates the virtual machines by passing control to the program in the virtual machine area 4 allocated to each virtual machine.

The central processing unit 1 has a program status word (hereinafter referred to as PSW) 5 and a control register 6 as specification information for program event recording (hereinafter referred to as PER).

As is well known, PER is a function whose purpose is to record the state of general-purpose registers of the central processing unit 1 during the execution of a required program for program debugging, etc. When bit 7 is on, control register 6 etc.
The detailed PER specification becomes effective, and records are collected according to the specification.

In that case, the predetermined 1 of the control register 6
If the designation bit 8 is on, it is designated to detect and record updates to, for example, 16 general-purpose registers provided in the central processing unit 1. The general-purpose registers to be monitored at this time are specified by associating 16 bits of the register specifying section 9 with each general-purpose register and turning on each bit.

An update detection circuit 10 is provided to monitor updates of general-purpose registers, and the circuit 10 detects updates of general-purpose registers using a known appropriate method, and when the general-purpose register is a register specified by the register specifying section 9, If the AND signal 11 of control bit 7 and designated bit 8 is on, the interrupt signal line 12 causes a so-called
Generates a PER interrupt signal.

An appropriate routine of the management program activated by the interrupt stores the updated contents of the general-purpose register in a predetermined storage area of the main memory.

In the virtual machine, use the above PER function,
When monitoring updates to general-purpose registers, by specifying the configuration using the configuration of the central processing unit 1, it is usually possible to detect updates to the specified register and generate an interrupt in the same way as described above. , in that case, the management program records information in a predetermined area of the virtual machine area 4 for the virtual machine.
You can perform PER.

However, as mentioned above, it is necessary for the VM monitor 3 to intervene and simulate certain processing, and in that case, as is well known, the PSW 5
The contents of various control registers including the control register 6 and the control register 6 are saved and saved in the virtual machine control area 13, and then replaced with the contents for executing the VM monitor 3.

Therefore, even if the general-purpose register specified in the PER of the virtual machine is updated by executing the VM monitor 3, it will generally not be detected by a PER interrupt.

For this reason, when the VM monitor 3 updates the general-purpose registers of the virtual machine, it identifies the contents of the PSW 5, control register 6, etc. of the virtual machine saved in the virtual machine control area 13.
It was necessary to simulate even the control functions leading to the PER interrupt, and this overhead was a factor in reducing the efficiency of virtual machine control.

[Means for solving problems]

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

In the figure, 20 is a designated display register, 21 is an update display register, and 22 is a VM status register.

[Effect]

The VM status register 22 is set to turn on the output signal line 24 when control is passed to the virtual machine, and is reset to off when transitioning to the VM monitor.

The designation display register 20 inputs the AND signal 11 of the control bit 7 of the PSW 5 and the designation bit 8 of the control register 6, and uses the input/output signals of the VM status register 22 to indicate that there is a transition from the virtual machine to the VM monitor. is set to the state of the input signal when detected.

The update display register 21 is the designated display register 2.
It is set to an on output by the logical product of the output of 0 and a signal sent from the update detection circuit 10 to the signal line 26, which indicates that any general-purpose register has been updated.

When the update display register 21 is turned on and a switching signal is issued for the VM status register 22 in order to migrate to a virtual machine, a PER interrupt signal is generated by the AND of both signals. Ru.

With the above configuration, if the general-purpose register update record is specified as PER in the virtual machine, and the general-purpose register is updated by moving to the VM monitor,
Afterwards, when control is returned to the virtual machine,
A PER interrupt will now occur.

Therefore, there is no need for the VM monitor to simulate the PER control function, and control overhead can be reduced.

〔Example〕

In FIG. 1, the PSW 5 of the central processing unit 1,
It is assumed that the control register 6, update detection circuit 10, etc. operate in the same manner as in the prior art except as described below.

The VM status register 22 is set by a signal line 23 to turn on an output line 24 when control is passed to the virtual machine, and is reset to OFF by a signal line 25 when transitioning to the VM monitor.

The designated display register 20 receives the AND signal 11 of the control bit 7 of the PSW 5 and the designated bit 8 of the control register 6, and detects from the input/output signal of the VM status register 22 that there is a transition from the virtual machine to the VM monitor. and is set to the state of the input signal.

Therefore, the designated display register 20 is set to ON when control is transferred from the virtual machine to the VM monitor 3 if the general-purpose register update record is designated in the virtual machine.

The update display register 21 is the designated display register 2.
0 output and the signal line 26 from the update detection circuit 10
is set on by the AND of the on signals of .

Here, an on signal is output to the signal line 26 when the update detection circuit 10 detects that any general-purpose register has been updated, and therefore the update display register 21 is connected to the VM monitor 3. Turns on when a general-purpose register is updated by executing , and general-purpose register update record is specified as the PER of the interrupted virtual machine at that time.

When the update display register 21 is turned on, when an on signal is output to the signal line 23 to change the VM state register 22 to the VM state in order to migrate to a virtual machine, the result is determined by the AND of both signals. An interrupt signal is then generated on signal line 27. This signal becomes an interrupt signal of the PER interrupt, which is equivalent to the interrupt signal 12 generated by the update detection circuit 10.

Designated display register 20 and update display register 2
1 is reset by signal line 23.

With the above configuration, if the general-purpose register update record is specified as PER in the virtual machine, and the general-purpose register is updated by moving to the VM monitor,
Afterwards, when control is returned to the virtual machine,
A PER interrupt will now occur.

[Effect of idea]

As is clear from the above explanation, in a computer system running a virtual machine, VM monitor control for simulating PER interrupts is no longer necessary, and the overhead of virtual machine control can be reduced. There is a significant industrial effect of improving performance.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention;
The figure is a block diagram of an example of a conventional configuration. In the figure, 1 is a processing device, 2 is a main storage device,
3 is VM monitor, 4 is virtual machine area, 5 is
PSW, 6 is control register, 7 is control bit, 8
9 is a designation bit, 9 is a register designation section, 10 is an update detection circuit, 20 is a designation display register, 21 is an update display register, and 22 is a VM status register.

Claims (1)

[Scope of Claims] 1. In the computers 1 and 2 that execute the virtual machine 4 and the monitor program 3 that controls the virtual machine, when control is transferred from the virtual machine to the monitor program, the general-purpose register of the virtual machine A first register 20 that holds program event recording specification information that specifies update event recording for a general-purpose register. A second register 21 that holds information indicating that a register has been updated, and a predetermined interrupt when control is transferred to the virtual machine when there is an update indication in the second register 21. A program event recording control method comprising means for generating a program event.