JP7754769B2 - Management device, management program, and electronic control device - Google Patents

Description

The present invention relates to a management device that manages the state transitions of a computer running multiple virtual machines, a management program executed by the management device, and an electronic control device equipped with the management device.

Patent Document 1 discloses a technology for individually transitioning the functions of multiple guest operating systems to a power-saving state. Note that in this specification, operating system is sometimes abbreviated as OS. In the following, the technology disclosed in Patent Document 1 will be referred to as the "conventional technology." In this conventional technology, conditions for transitioning to a power-saving state are set for each individual OS, and an OS that meets these conditions is transitioned to a power-saving state. In this conventional technology, when all OSes have transitioned to a power-saving state, the hypervisor is transitioned to a power-saving state and hardware resources are stopped.

JP 2012-178006 A

In conventional technology, hardware resources can only be stopped when all guest OSs satisfy the transition conditions. Therefore, if multiple guest OSs are equipped with functions that result in a relatively large time difference in the timing of their transition to a power-saving state, it may take a relatively long time for all guest OSs to satisfy the transition conditions, which could result in insufficient power-saving effects. For example, if a guest OS is equipped with the functions of an electronic control unit installed in a vehicle, the transition conditions may include the state of the vehicle's power supply. Note that in this specification, the electronic control unit may sometimes be abbreviated as ECU.

Vehicle power sources include the +B power source, which is on when the battery is connected, and the ignition power source, which is on when the engine is running. Note that in this specification, ignition is sometimes abbreviated as IG. If a guest OS on a hypervisor is equipped with an ECU function whose transition condition is the +B power source state and an ECU function whose transition condition is the IG power source state, even if the engine is stopped and the guest OS whose transition condition is the IG power source state can transition to a power-saving state, hardware resources cannot be shut down unless the transition condition of the guest OS whose transition condition is the +B power source state is met. As a result, significant power-saving effects cannot be achieved. This problem becomes more pronounced the greater the time difference between the transition timings of each guest OS.

The present invention was made in consideration of the above circumstances, and its purpose is to provide a management device, management program, and electronic control device that can enhance power saving effects.

The management device described in claim 1 manages state transitions of a computer (3) running multiple virtual machines (11-14). Each of the multiple virtual machines transitions from a wake-up state, in which it performs a specified operation, to a sleep state, in which it stops operating, when predetermined sleep conditions are met. The computer can transition between a normal state, in which it performs normal operation, and multiple power-saving states that consume less power than the normal state.

The management device includes a state management table that displays information about the state of each of the multiple virtual machines, an access management table that displays information about the hardware (4-8) of the computer accessed by each of the multiple virtual machines, and a transition condition table that displays information about the transition conditions for transitioning the computer to each of the multiple power-saving states. The management device references the state management table, access management table, and transition condition table, and transitions the computer to one of the multiple power-saving states that is currently available and consumes the least amount of power.

With this configuration, each time one of the multiple virtual machines is able to transition to a sleep state, the computer's state transitions to the power-saving state with the lowest power consumption among the states available at that time. In other words, with this configuration, the computer's state can be transitioned in stages to further reduce power consumption, i.e., multi-stage power-saving transitions can be realized. Therefore, with this configuration, it is possible to achieve the maximum possible power-saving effect for the computer even if all virtual machines have not transitioned to a sleep state. Therefore, with this configuration, the power-saving effect can be significantly improved compared to conventional technology.

FIG. 2 is a diagram illustrating a configuration of an integrated ECU according to an embodiment. FIG. 1 is a diagram schematically illustrating an example of a status management table according to an embodiment; FIG. 1 is a diagram illustrating an example of an access management table according to an embodiment. FIG. 1 is a diagram schematically illustrating an example of a transition condition table according to an embodiment. FIG. 10 is a diagram schematically illustrating the contents of a determination process according to an embodiment.

Hereinafter, embodiments of a management device, a management program, and an electronic control device will be described with reference to the drawings.
As shown in Figure 1, the integrated ECU 1 of this embodiment is mounted on a vehicle such as an automobile, and the functions of multiple ECUs, which conventionally operated independently, are mounted on the chip of a single microcomputer 3 via a hypervisor 2. In this case, the functions of the multiple ECUs are mounted in units called virtual machines. Note that in this specification, the microcomputer may be abbreviated as "micon," the hypervisor may be abbreviated as "HV," and the virtual machine may be abbreviated as "VM."

In this embodiment, the functions of four ECUs, namely, the engine ECU, air conditioning ECU, central gateway ECU, and body ECU, are exemplified as the functions of the multiple ECUs provided in the integrated ECU 1. However, the integrated ECU 1 may have the functions of two or three ECUs, or may have the functions of five or more ECUs. Note that in this specification, the central gateway is sometimes abbreviated as CGW. In this case, the engine ECU is realized by VM11, the air conditioning ECU is realized by VM12, the CGW ECU is realized by VM13, and the body ECU is realized by VM14.

VMs 11 to 14 are assigned a VMID, which is identification information for identifying each of them. In this embodiment, VM 11 is assigned "VMID=1", VM 12 is assigned "VMID=2", VM 13 is assigned "VMID=3", and VM 14 is assigned "VMID=4". Microcomputer 3 is an example of a computer, and its hardware includes two CPUs 4 and 5 and various peripherals. Note that microcomputer 3 may be configured with one CPU or three or more CPUs. Note that in this specification, hardware may be abbreviated as HW.

The various peripherals include a CAN communication interface 6 for CAN communication, an Ethernet communication I/F 7 for Ethernet communication, a timer 8, and the like. CAN is an abbreviation for Controller Area Network and is a registered trademark. Ethernet is also a registered trademark. In this specification, interface is sometimes abbreviated as I/F. Each piece of HW provided in the microcomputer 3 is assigned an HWID, which is identification information for identifying it. In this embodiment, CPU 4 is assigned "HWID=1", CPU 5 is assigned "HWID=2", CAN communication I/F 6 is assigned "HWID=3", Ethernet communication I/F 7 is assigned "HWID=4", and timer 8 is assigned "HWID=5".

The microcomputer 3 can determine the status of the vehicle power supply, which is a power source installed in the vehicle, based on the presence or absence of a response from a specified input terminal. The vehicle power supply includes the +B power supply 9, which is turned on when the battery is connected, and the IG power supply 10, which is turned on when the engine is running. The microcomputer 3 can also determine the status of CAN and Ethernet communications via the CAN communication I/F 6 and Ethernet communication I/F 7, specifically the presence or absence of communication. Specifically, the microcomputer 3 can determine that there is no communication if, for example, there is no response to communication for a specified period of time.

HV2 operates VMs 11-14 on microcomputer 3 and functions as a management device that controls the state transitions of microcomputer 3. In this case, integrated ECU 1 is an example of an electronic control device that includes microcomputer 3, VMs 11-14 that operate on microcomputer 3, and HV2 that functions as a management device. HV2 and VMs 11-14 are both realized by the CPU of microcomputer 3 executing computer programs stored on non-transient physical storage media and performing processes corresponding to the computer programs; in other words, they are realized by software. Of the computer programs mentioned above, the program executed by HV2 corresponds to the management program.

When predetermined sleep conditions are met, each of VMs 11-14 transitions from a wake-up state, in which a predetermined operation is performed, to a sleep state, in which the predetermined operation is stopped. The predetermined operation corresponds to various operations for realizing the functions of the ECU corresponding to each of VMs 11-14. For example, in the case of VM 11, it is an operation for controlling the engine, and in the case of VM 12, it is an operation for controlling the air conditioner.

Sleep conditions can include, for example, the state of the vehicle power supply and the state of CAN and Ethernet communications. In this embodiment, the sleep conditions for VM11 and VM12 include the state of the IG power supply 10, and the sleep conditions for VM13 and VM14 include the state of the +B power supply 9. When the sleep conditions are met, each of VM11 to VM14 sends a state transition request to HV2. The state transition request includes the VMID of the VM that sent it to identify the sender of the request. When HV2 receives a state transition request, it executes the determination process described below.

The microcomputer 3 can transition between a normal state in which it operates normally and multiple power-saving states that consume less power than the normal state. The multiple power-saving states include "HALT," "STOP," "PERIPHERALSTOP," and "DEEPSTOP." The degree of power saving, that is, the degree to which the power consumption of the microcomputer 3 is reduced, is as shown in Figure 4, which will be described later. That is, "HALT" has the smallest power saving degree and "DEEPSTOP" has the largest power saving degree. The power saving degrees of "STOP" and "PERIPHERALSTOP" are intermediate between these two.

HV2 has a state management table, an access management table, and a transition condition table. Each of these tables only needs to be readable and writable by HV2, and may be stored in various storage devices provided in the microcomputer 3, or in various storage devices provided external to the microcomputer 3. The state management table is a table that shows information about the state of each of the multiple VMs 11-14, and has the contents shown in Figure 2, for example.

In other words, the state management table associates VMIDs with VM states. VM states include the wakeup state and sleep state mentioned above. Note that in Figure 2, the wakeup state and sleep state are abbreviated as wakeup and sleep, respectively. There are as many VMIDs as there are VMs installed on the HV2.

The state management table shown in FIG. 2 indicates that VM11, assigned VMID=1, and VM12, assigned VMID=2, are in a sleep state, while VM13, assigned VMID=3, and VM14, assigned VMID=4, are in a wake-up state. The state management table is updated when the sleep condition is met for at least one of the multiple VMs 11-14. Specifically, when a state transition request is sent from one of VMs 11-14, the state management table is updated so that the state of the VM associated with the VMID corresponding to the VM that sent the state transition request becomes a sleep state.

The access management table is a table that shows information about the hardware of the microcomputer 3 that is accessed by each of the multiple VMs 11-14, and has the contents shown in Figure 3, for example. In other words, the access management table links information about the CPU and peripherals with the VMIDs of the multiple VMs 11-14 that access them.

Specifically, the access management table contains elements such as information about the HW of the microcomputer 3, the access VM, and the access status. Information about the HW of the microcomputer 3 includes the HWID and hardware type. The hardware type is broadly categorized into "CPU" and "peripheral," and each HW is identified by its own unique name. In Figure 3, "CPU[1]" represents CPU 4, "CPU[2]" represents CPU 5, "CAN" represents CAN communication I/F 6, "Ethernet" represents Ethernet communication I/F 7, and "timer" represents timer 8.

The VMID of the VM that accesses the corresponding HW is entered in the Access VM field. In this case, since VMs 11 and 12 are accessing CPU 4, "1, 2" are entered in the Access VM field corresponding to "HWID=1", and since VMs 13 and 14 are accessing CPU 5, "3, 4" are entered in the Access VM field corresponding to "HWID=2".

In this case, since VMs 11 and 13 are accessing CAN communication I/F 6, "1, 3" is entered in the access VM item corresponding to "HWID=3", since VM 12 is accessing Ethernet communication I/F 7, "2" is entered in the access VM item corresponding to "HWID=4", and since VMs 11 and 14 are accessing timer 8, "1, 4" is entered in the access VM item corresponding to "HWID=5".

The access state is represented as "Yes" when there is access to the corresponding HW, and as "No" when there is no access to the corresponding HW. The access state is updated as follows. That is, when all of the VMs with the VMIDs listed in the access VM transition to the sleep state, the access state is updated from "Yes" to "No." In other words, if even one of the VMs with the VMIDs listed in the access VM is in the wake-up state, the access state remains "Yes." According to the access management table shown in Figure 3, it can be seen that because VMs 11 and 12 have transitioned to the sleep state, the access states of CPU 4 and Ethernet communication I/F 7 are "No," and the access states of the other HW are "Yes."

The transition condition table is a table that displays information about the transition conditions, which are the conditions for transitioning the microcomputer 3 to each of multiple power saving states, and may have the contents shown in Figure 4, for example. Such a transition condition table can be created based on the hardware manual for the microcomputer 3. The transition condition table contains elements such as the power saving state name, which is the name of the power saving state defined for the microcomputer 3, the transition conditions, which are the conditions for transitioning to each power saving state, and the degree of power saving in each power saving state. Note that, below, each power saving state will be referred to by its power saving state name.

The transition condition for "HALT" is "there is no access from the sole VM to the sole CPU," and the degree of power saving is "small." For example, in the case of a CPU accessed by two VMs, "HALT" can be used to transition when there is no access from one of the two VMs. By temporarily stopping the CPU during the gap when the other of the two VMs is not operating, i.e., not accessing the CPU, the power consumption of the microcontroller 3 is reduced.

The transition condition for "STOP" is "no access from any VMs to a single CPU," and the power saving level is "medium." For example, for a CPU accessed by two VMs, "STOP" can be transitioned to when there is no access from either of the two VMs, and by stopping that CPU, the power consumption of the microcontroller 3 is reduced. In this case, the HV2 will stop accessing the stopped CPU, further reducing power consumption accordingly.

The transition condition for "PERIPHERALSTOP" is "no access from VMs to any peripherals," and the power saving level is "medium." "PERIPHERALSTOP" can be transitioned to when there is no access from any VM to any peripherals, i.e., the CAN communication I/F 6, Ethernet communication I/F 7, and timer 8. By stopping all peripherals, the power consumption of the microcontroller 3 is reduced.

The transition conditions for "DEEPSTOP" are that "all CPUs are not accessed by VMs" and "all peripherals are not accessed by VMs," and the degree of power saving is "large." "DEEPSTOP" can be transitioned to when all CPUs and peripherals are not accessed by any VMs, and by stopping all CPUs and all peripherals, in other words, stopping almost all functions, the power consumption of the microcontroller 3 is reduced. In this case, the HV2 also enters sleep state and stops its functions.

The HV2 references the above-mentioned tables, namely the state management table, the access management table, and the transition condition table, and transitions the microcomputer 3 to one of the multiple power-saving states that is currently available and consumes the least amount of power. Such state transitions of the microcomputer 3 are realized by the HV2 executing a determination process. As described above, the determination process is executed when the HV2 receives a state transition request sent from VMs 11-14, and is, for example, the process shown in Figure 5.

First, in step S101, the VMID of the VM that sent the state transition request is obtained. The VMID is obtained by reading the VMID included in the received state transition request. After step S101 is executed, the process proceeds to step S102, where the state management table is updated. Specifically, in step S102, the state management table is updated so that the state of the VM corresponding to the VMID that matches the VMID obtained in step S101 is set to sleep.

After step S102 is executed, the process proceeds to step S103, where the information corresponding to the first HWID in the access management table, i.e., "HWID=1," is obtained. After step S103 is executed, the process proceeds to step S104, where it is determined whether all VMs listed as access VMs in the information obtained in step S103 are in a sleep state. This determination can be made based on the state management table.

Here, if all VMs are in a sleep state, step S104 results in "YES" and the process proceeds to step S105. On the other hand, if all VMs are not in a sleep state, in other words, if at least one VM is in a wake-up state, step S104 results in "NO", and the process proceeds to step S106 without executing step S105. In step S105, the access state corresponding to the HWID obtained in step S103 is set to "none."

In step S106, it is determined whether the information acquired in step S103 is the last information, that is, whether there is any HW for which information has not been acquired other than the HW corresponding to the information acquired in step S103. If the information acquired in step S103 is not the last information, step S106 returns "NO" and the process proceeds to step S107. In step S107, the information corresponding to the next HWID from the information corresponding to the HWID in the access management table is acquired.

Here, "next" refers to the information corresponding to the HWID in the access management table that has not yet been obtained in this series of processes and has the smallest HWID number. After step S107 is executed, the process returns to step S104. On the other hand, if the information obtained in step S103 is the last information, step S106 returns "YES" and the process proceeds to step S108. In step S108, it is determined whether there is a power saving state to which a transition can be made at that time, based on the access status of each HW in the access management table and the transition conditions in the transition condition table.

If there is no power-saving state to which a transition can be made, step S108 returns "NO" and the process ends. On the other hand, if there is a power-saving state to which a transition can be made, step S108 returns "YES" and the process proceeds to step S109. In step S109, the state of the microcomputer 3 is transitioned to the state with the greatest degree of power saving among the power-saving states to which a transition can be made. After step S109 is executed, the process ends.

Next, we will explain the specific flow of operation of each part when the determination process is executed by HV2. Note that here we assume a case where VMs 11, 12, 13, and 14 send state transition requests to HV2 in this order, i.e., they transition to sleep state in this order. First, when VM 11 sends a state transition request to HV2, HV2, upon receiving it, updates the state of the VM corresponding to "VMID=1" in the state management table to "sleep."

Then, HV2 checks the access management table for HWID=1 to 5 in order and updates the access state. At this time, only VM11 is in the sleep state, and the other VMs 12 to 14 are in the wake-up state, so all access states remain "Yes" and are not updated. HV2 then compares the access states in the access management table with the transition conditions in the transition condition table. At this time, VM11 is no longer accessing CPU4, so the transition condition to "HALT" is met. Note that at this time, the transition conditions to other power-saving states are not met. Therefore, HV2 transitions the state of microcomputer 3 to "HALT."

Next, when VM12 sends a state transition request to HV2, HV2, upon receiving it, updates the state of the VM corresponding to "VMID=2" in the state management table to "Sleep." HV2 then sequentially checks HWID=1 to 5 in the access management table and updates the access state. At this time, because VM12, in addition to VM11, is in the sleep state, the access state of CPU [1] corresponding to "HWID=1," i.e., CPU 4, is updated to "None," and the access state of Ethernet corresponding to "HWID=4," i.e., Ethernet communication I/F 7, is updated to "None."

Then, HV2 compares the access status in the access management table with the transition conditions in the transition condition table. At this time, because VMs 11 and 12 no longer access CPU 4, the transition conditions to "STOP" in addition to "HALT" are met. Note that at this time, the transition conditions to other power-saving states are not met. Therefore, HV2 transitions the state of microcomputer 3 to "STOP," which is the state with the greatest degree of power saving among the available power-saving states.

Next, VM13 sends a state transition request to HV2. Upon receiving this, HV2 updates the state of the VM corresponding to "VMID=3" in the state management table to "Sleep." HV2 then checks HWID=1 to 5 in order in the access management table to update the access state. At this time, because VM13, in addition to VM11 and 12, is in the sleep state, the access state of the CAN corresponding to "HWID=3," i.e., the CAN communication I/F 6, is updated to "None." HV2 then compares the access state in the access management table with the transition conditions in the transition condition table, but because no new transition conditions are met, the state of the microcontroller 3 remains "STOP."

Next, when VM14 sends a state transition request to HV2, HV2 receives it and updates the state of the VM corresponding to "VMID=4" in the state management table to "Sleep." HV2 then checks HWID=1 to 5 in order in the access management table and updates the access state. At this time, because VM14, in addition to VM11 to 13, is in the sleep state, all access states are updated to "None."

Then, the HV2 compares the access states in the access management table with the transition conditions in the transition condition table. At this point, because VMs 11-14 no longer access all HW, the transition conditions for "PERIPHERALSTOP" and "DEEPSTOP" in addition to "HALT" and "STOP" are met. Therefore, the HV2 transitions the state of the microcomputer 3 to "DEEPSTOP," which is the state with the greatest degree of power saving among the available power saving states.

According to the present embodiment described above, the following effects can be obtained.
The HV2 refers to a state management table that shows information about the state of each of the multiple VMs 11 to 14, an access management table that shows information about the hardware that the microcontroller 3 has that is accessed by each of the multiple VMs 11 to 14, and a transition condition table that shows information about the transition conditions that are the conditions for transitioning the microcontroller 3 to each of the multiple power saving states, and performs a determination process to transition the microcontroller 3 to one of the multiple power saving states that is possible to transition to at that time and has the lowest power consumption.

With this configuration, each time one of the multiple VMs 11-14 is able to transition to a sleep state, the state of the microcomputer 3 transitions to the power-saving state with the lowest power consumption of those available at that time. In other words, with the above configuration, the state of the microcomputer 3 can be transitioned in stages to further reduce power consumption, i.e., multi-stage power-saving transitions can be realized. Therefore, with the above configuration, it is possible to obtain the power-saving effect of the microcomputer 3 to the extent possible, even if all VMs 11-14 have not transitioned to a sleep state. Therefore, with this embodiment, the power-saving effect can be significantly improved compared to conventional technology.

In addition, in this case, when any of VMs 11 to 14 are able to transition to a sleep state, HV2 transitions the state of microcontroller 3 to a power-saving state that does not affect the operation of VMs other than the VM that is able to transition to a sleep state, i.e., VMs in a wake-up state. In this way, when any of VMs 11 to 14 transition to a sleep state, it is possible to prevent the continuation of a specified operation by another VM that is currently executing that operation from being interrupted.

In the above configuration, the sleep conditions for VM11 and VM12 include the state of the IG power supply 10, and the sleep conditions for VM13 and VM14 include the state of the +B power supply 9. In such a case, there is a high possibility that a relatively large time difference will occur between the transition timing of VM11, 12 and VM13, 14 to the sleep state. In conventional technology, in such a case, there is a risk that a sufficient power saving effect will not be obtained. In contrast, according to this embodiment, even if a relatively large time difference occurs between the transition timing of each VM to the sleep state, a sufficient power saving effect can be obtained because multi-stage power saving transitions are performed as described above.

The state management table of this embodiment represents information about the state of each of the multiple VMs 11-14, and is updated when the sleep conditions are met for at least one of the multiple VMs 11-14. This state management table makes it possible to manage the sleep state for each VM, and realizes the multi-stage power saving transition control described above when multiple VMs 11-14 are installed on the microcomputer 3, as in this embodiment.

The microcomputer 3 of this embodiment includes, as its hardware, CPUs 4 and 5, and peripherals such as a CAN communication I/F 6, an Ethernet communication I/F 7, and a timer 8. The access management table of this embodiment links information about the CPUs 4 and 5 and each peripheral with VMIDs, which are identification information for identifying each of the multiple VMs 11-14 that access them. This makes it possible to have access HW information for each VM, and to gradually transition the power saving state of the microcomputer 3.

(Other embodiments)
The present invention is not limited to the embodiments described above and illustrated in the drawings, but can be arbitrarily modified, combined, or expanded without departing from the spirit of the invention.
The numerical values and the like shown in the above embodiment are examples and are not limited to these.
The present invention is not limited to applications for managing the state transitions of the microcomputer 3 that constitutes the integrated ECU 1 installed in a vehicle, but can be applied to general applications for managing the state transitions of a computer that runs multiple virtual machines.

While the present disclosure has been described with reference to exemplary embodiments, it is understood that the present disclosure is not limited to those embodiments or structures. The present disclosure also encompasses various modifications and variations within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

The control unit and method described in this disclosure may be implemented by a special-purpose computer provided by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and method described in this disclosure may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and method described in this disclosure may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible recording medium.

1...Integrated ECU, 2...Hypervisor, 3...Microcomputer, 4, 5...CPU, 6...CAN communication interface, 7...Ethernet communication I/F, 8...Timer, 11-14...Virtual machine.

Claims (5)

A management device (2) that manages state transitions of a computer (3) that runs multiple virtual machines (11 to 14),
When a predetermined sleep condition is satisfied, each of the plurality of virtual machines transitions from a wake-up state in which a predetermined operation is performed to a sleep state in which the operation is stopped,
the computer is capable of transitioning to one of a normal state in which it operates normally and a plurality of power-saving states in which it consumes less power than the normal state;
a state management table representing information about a state of each of the plurality of virtual machines;
an access management table representing information about hardware (4-8) of the computer to be accessed by each of the plurality of virtual machines;
a transition condition table representing information on transition conditions that are conditions for transitioning the computer to each of the plurality of power saving states;
Equipped with
A management device that refers to the state management table, the access management table, and the transition condition table, and transitions the computer to one of the multiple power saving states that can be transitioned to at that time and that consumes the least power. The management device described in claim 1, wherein the state management table is updated when the sleep condition is satisfied for at least one of the plurality of virtual machines. The computer includes a CPU (4, 5) and peripherals (6-8) as its hardware.
3. The management device according to claim 1, wherein the access management table associates information about the CPU and peripherals with identification information for identifying each of the plurality of virtual machines accessing them. A management program executed by a management device that manages state transitions of a computer running a plurality of virtual machines,
When a predetermined sleep condition is satisfied, each of the plurality of virtual machines transitions from a wake-up state in which a predetermined operation is performed to a sleep state in which the operation is stopped,
the computer is capable of transitioning to one of a normal state in which it operates normally and a plurality of power-saving states in which it consumes less power than the normal state;
The management device
a process of referring to a state management table that indicates information about the state of each of the plurality of virtual machines, an access management table that indicates information about hardware that the computer has and that is accessed by each of the plurality of virtual machines, and a transition condition table that indicates information about transition conditions that are conditions for transitioning the computer to each of the plurality of power saving states, and transitioning the computer to one of the plurality of power saving states that can be transitioned to at that time and that consumes the least amount of power;
A management program that runs the An electronic control device (1) including a computer (3), a plurality of virtual machines (11 to 14) running on the computer, and a management device (2) that manages state transitions of the computer,
When a predetermined sleep condition is satisfied, each of the plurality of virtual machines transitions from a wake-up state in which a predetermined operation is performed to a sleep state in which the operation is stopped,
the computer is capable of transitioning to one of a normal state in which it operates normally and a plurality of power-saving states in which it consumes less power than the normal state;
The management device
a state management table representing information about a state of each of the plurality of virtual machines;
an access management table representing information about hardware (4-8) of the computer to be accessed by each of the plurality of virtual machines;
a transition condition table representing information on transition conditions that are conditions for transitioning the computer to each of the plurality of power saving states;
Equipped with
An electronic control device that refers to the state management table, the access management table, and the transition condition table, and transitions the computer to one of the multiple power saving states that can be transitioned to at that time and that consumes the least power.