JPH0754470B2 - Control method for virtual computer system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a virtual machine (VM) system, and in particular, a VM start instruction loads information in a VM information area into hardware of a real computer to execute VM running. A virtual computer system in a state.

[Conventional technology]

For a conventional virtual machine system in which the information of the VM information area in the main memory is loaded into the hardware of the real machine by the VM start instruction and the virtual machine is in the VM running state, see
Gazette, and IBM System / 370 XA Interpretive Execution (SA
22-7095-0) (IBM System / 370XA Interpretive Executi
on (SA22-7095-0).

[Problems to be solved by the invention]

In the above conventional technology, the VM information area (VMIR) has 256 bytes, and every time the VM boot instruction is issued, all the scheduled fields in the VMIR are loaded into the scheduled hardware of the real computer, Since the field in VMIR that does not change the hardware state before and after loading is also loaded, it is not considered that unnecessary reading of main memory and loading of read data to hardware occur. For this reason, it takes a lot of time to execute the VM start instruction each time.

The purpose of the present invention is to eliminate VM
To reduce the dispatch time.

[Means for solving problems]

For the above purpose, the VMIR field that does not need to be loaded and whose hardware status does not change even when the VMIR information is loaded,
This is achieved by the virtual machine monitor (VMM) specifying that the VM start instruction is controlled not to read the field of the VMIR that does not need to be loaded from the main memory and load it into the hardware.
VMM sets the load level that specifies which field of VMIR is loaded to the hardware in a predetermined main storage area in advance for each VM (virtual machine),
The above object is achieved by selecting a field to be loaded in the VMIR according to the load level when the VM start instruction is executed and loading it into the hardware. In addition,
This load level may be specified in the command word field of the VM start instruction itself.

[Action]

A load level specification means for specifying whether or not each field of the VM information area VMIR specified by the VM start instruction is loaded to the hardware is provided.
By setting the load level in the field of the instruction word of the boot instruction itself so that the field that is loaded into hardware and the field that is not loaded can be identified, there is no need to load it in hardware when the VM boot instruction is executed. The VMIR field read and hardware load operations can be omitted, and the processing time of the VM start instruction can be shortened.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. Operand address of VM start instruction is VM in main memory (MS) 1
It is the start address of the information area (VMIR) 2. In this embodiment, the load level designation area (LLIR) 3 is set to VMIR2.
It will be installed on the MS1 that follows, and the VMM will predetermine the load level before issuing the VM start instruction and store it in the LLIR3. Bits 0 to 23 of LLIR3 are prefix values PFX ... 100 VM main memory start address STA ... 101 〃 〃 upper limit address ULA ... 102 General-purpose registers GR14-15 ... 103,104 CPU timer CPUT ... 105 Clock comparator CKC ... 106 Corresponding to control registers CRO-15 ... 107-122 PSW ... 123.

To execute the VM start instruction, read LLIR3, and then bits 0-2
The field in VMIR2 corresponding to the bit that is '1' out of 3 is read and loaded into the predetermined hardware in CPU4. Table 1 shows the correspondence between VMIR2 fields and CPU4 hardware.

Next, the setting of LLIR3 is described.

When the VM is running, for example, when the time slice is used up, or when the PSW enters the WAIT state, the VM issues an interrupt and the control is transferred to the VMM. In this case, VMM
Then dispatch the VM. Ie the next VM to be executed
Is different from the VM that was running immediately before, but at this time,
Normally, all the predetermined fields of VMIR2 must be loaded to the hardware of CPU4, so VMM sets all the bits (bits 0 to 23) of LLIR3 to "1" before issuing the VM start instruction. .

On the other hand, while VM is running, an instruction that VM cannot directly execute appears,
When an interrupt occurs to request the VMM to simulate the instruction, control is transferred to the VMM, and the simulation of the instruction is completed, the VMM is the VM that was executing immediately before.
To dispatch again. In such a case, normal CPU4
VM dedicated hardware inside, VPXR200A in this embodiment,
(The prefix register of the actual machine exists separately in PXR200B.), STAR201, and ULAR202 are not used in VMM, so these contents are the same as before VM was transferred to VMM. Therefore, bits 0, 1, and 2 of LLIR3 corresponding to these hardware are set to '0'. In other hardware as well, if there is no change during transition from VM to VMM and during VMM running, set the corresponding LLIR3 bit to '0'. As a result, in the VM start instruction, LLIR
The VMIR2 field in which the 3rd bit is '0' is not read from MS1 and the load operation to the hardware is not performed, so the processing time of VM start instruction is shortened and the overhead of VM dispatch can be reduced There is.

〔The invention's effect〕

According to the present invention, the VM information area VM specified by the VM start instruction
A load level designating means for designating whether or not each field of the IR is loaded into hardware is provided, and the VMM is configured to specify the load level before issuing the VM start instruction or in the field of the instruction word of the VM start instruction itself By setting so that the fields to be loaded into and those not to be loaded can be identified, it is possible to omit the VMIR field reading that does not need to be loaded into the hardware and the loading operation to the hardware when the VM start instruction is executed. Since the processing time of the start instruction can be shortened, the VM overhead can be reduced. Further, according to the present invention, even if the hardware register is not changed, when the virtual computer monitor changes the register of the virtual computer information storage area of the virtual computer in the main memory, the load level of the virtual computer is changed. Is specified in the main memory, there is an effect that only the changed portion can be loaded into the predetermined hardware.
Furthermore, since the load level is set in the main memory for multiple virtual machines, for example, the virtual machine monitor simulates the instructions of multiple virtual machines and sets the simulation results to set the virtual machine information. Even when the storage area is updated, there is an effect that only the changed portion can be loaded into the predetermined hardware for each virtual computer.

[Brief description of drawings]

FIG. 1 is a diagram showing an MS and VMIR, LLIR, and CPU in the MS according to an embodiment of the present invention. 1 ... Main memory (MS) 2 ... VM information area (VMIR) 3 ... Load level specification area (LLIR) 4 ... CPU

Claims (1)

[Claims] 1. A main memory which comprises a plurality of virtual machines and a virtual machine monitor which manages the plurality of virtual machines, and which stores information about the virtual machines when the virtual machine monitor dispatches the virtual machines. The virtual computer information storage area is designated, the virtual computer information storage area information is issued to the scheduled hardware of the real computer by issuing a virtual machine start instruction, and the virtual computer system enters the virtual machine running state. In the control method, the virtual computer information storage area is divided into a plurality of areas, and the virtual computer monitor displays a load level indicating which area information is to be loaded into the scheduled hardware of the real computer. It is specified in the main memory for each virtual computer, and when the virtual computer start instruction is issued, it is started by the virtual calculation start instruction. Control method of a virtual computer system, characterized by selectively load some or all of the information of the virtual computer information storage area on the intended hardware real machine according to a load level corresponding to the virtual machine.