JP7090080B2 - Hypervisor program - Google Patents

Description

The present invention relates to a hypervisor program that enables data communication between virtual machines.

In the field of information technology, virtualization technology that has merits such as cost reduction, power consumption reduction, and high agility has become widespread, and cloud computing such as Infrastructure as a Service (IAAS) and Software as a Service (SaaS) It is used as a basic technology. Also, in the communication service business, virtualization technology has become the basic technology of NFV (Network Function Virtualization), and with the progress of IoT (Internet of Things), it has become a control technology field for automobiles, factories, home appliances, etc. Is also expanding.

By using the virtualization technology, it is possible to operate a plurality of virtual computers on one physical computer. Specifically, the hypervisor running on the physical computer makes the virtual machine equipped with the virtual CPU (Central Processing Unit), virtual memory, virtual storage, and virtual NIC (Network Interface Card) function, and the guest OS is on this virtual computer. (Operating System) is running. The virtual machine can communicate with other virtual machines by using the functions of the virtual NIC and the virtual network provided by the hypervisor (Non-Patent Document 1).

Jian Wang et al., "XenLoop: A Transparent High Performance Inter-VM Network Loopback," [online], [Search June 14, 2017], Internet <URL: http://osnet.cs.binghamton.edu/publications/ wang08xenloop.pdf ＞

In communication via a virtual NIC and a virtual network, a handshake process for opening a communication path is required before starting transmission / reception of communication data. Also, from the application on the sending guest OS to the sending guest OS, from the sending guest OS to the sending virtual NIC, from the sending virtual NIC to the receiving virtual NIC, from the receiving virtual NIC to the receiving guest OS, and , Communication processing takes time because there are five data copies from the receiving side guest OS to the application on the receiving side guest OS. Non-Patent Document 1 describes a device for reducing the number of times data is copied, but further speeding up is required.

The present invention has been made in view of such a background, and it is an object of the present invention to provide a hypervisor program that enables high-speed data communication between virtual machines.

In order to solve the above-mentioned problems, the present invention is a hypervisor that operates a plurality of virtual machines on a physical computer and mediates data communication between the virtual machines, and is a data transmission side of the virtual machines. When the transmission side virtual machine is notified of the transmission memory area, the reception side virtual machine which is the data receiving side of the virtual machine is interrupted to notify the reception request, and the reception side virtual computer notifies the reception memory area. When the notification is received, the hypervisor program for realizing a hypervisor having a memory copy unit that copies the data in the transmission memory area to the reception memory area is used.

By doing so, the physical computer can transmit data from the transmission memory area to the reception memory area with one copy. This makes it possible to transmit data from the transmitting side virtual machine to the receiving side virtual machine at high speed.

According to the present invention, it is possible to provide a hypervisor program that enables high-speed data communication between virtual machines.

It is a figure which shows the whole structure of the host computer which concerns on 1st Embodiment. It is a sequence diagram which shows the flow of the data transmission process from a virtual machine to a virtual machine started by the virtual machine on the receiving side which concerns on 1st Embodiment. It is a sequence diagram which shows the flow of the data transmission processing from the virtual machine to the virtual machine which concerns on the modification 3 of 1st Embodiment. It is a sequence diagram which shows the flow of the data transmission processing from virtual machine to virtual machine which the virtual machine of the transmission side which concerns on 2nd Embodiment starts. It is a figure which shows the whole structure of the host computer which concerns on 3rd Embodiment. It is a figure for demonstrating the state of mapping between the virtual memory of the virtual computer and the physical memory of a host computer which concerns on 3rd Embodiment. It is a sequence diagram which shows the flow of the data transmission process by changing the memory mapping from the virtual machine to the virtual machine which concerns on 3rd Embodiment. It is a figure which shows the state of mapping between the virtual memory of a virtual computer and the physical memory of a host computer at the time when the virtual computer secures the received memory page which concerns on 3rd Embodiment. It is a figure which shows the state of the mapping between the virtual memory of a virtual computer and the physical memory of a host computer at the time of changing the memory mapping which concerns on 3rd Embodiment. It is a sequence diagram which shows the flow of the data transmission process by changing the mapping of a plurality of memory pages between a virtual machine and a virtual machine which concerns on modification 2 of 3rd Embodiment. It is a figure which illustrates the data structure of the virtual computer database stored in the storage which concerns on 4th Embodiment. It is a figure which illustrates the data structure of the information flow control management database stored in the storage which concerns on 4th Embodiment. It is a sequence diagram which shows the flow of the data transmission processing from the virtual machine with the information flow control to the virtual machine which concerns on 4th Embodiment. FIG. 5 is a sequence diagram showing a flow of data transmission processing by changing a memory mapping from a virtual machine to a virtual machine with information flow control according to a fifth embodiment.

Hereinafter, embodiments (embodiments) for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an overall configuration of the host computer 10 according to the first embodiment. The host computer (physical computer) 10 includes a CPU 31, a memory 32, a storage 33, an input / output unit 34, a hypervisor 20, and a virtual computer (60, 70).

The CPU 31 executes a program stored in the storage 33 to operate the hypervisor 20 and the virtual machines (60, 70) on the hypervisor 20, which will be described later. The memory 32 stores data necessary for processing executed by the CPU 31. The storage 33 stores programs and data of the hypervisor 20 and virtual machines (60, 70). The input / output unit 34 exchanges data with other calculators, displays (not shown), and keyboards (not shown).

The hypervisor 20 virtualizes the CPU 31, the memory 32, the storage 33, and the input / output unit 34 to operate a virtual computer. The hypervisor 20 includes a memory copy unit 21 that copies data in the virtual memory of the virtual machine 60 to the virtual memory of the virtual machine 70, and mediates data communication between the virtual machines (60, 70).

The virtual computer 60 is a virtual computer on the hypervisor 20, and is an application running on a virtual CPU 61, a virtual memory 62, a virtual storage (not shown), a virtual input / output unit (not shown), a guest OS65, and a guest OS65. (Not shown) is included. The virtual CPU 61, the virtual memory 62, the virtual storage (not shown), and the virtual input / output unit (not shown) are virtual CPUs, memories, storage, and input / output units provided by the hypervisor 20 and included in the virtual computer 60. ..

The guest OS 65 is an OS that operates on virtual hardware of a virtual CPU 61, a virtual memory 62, a virtual storage (not shown), and a virtual input / output unit (not shown). When the guest OS 65 requests a service from the hypervisor 20, it calls the service using HVC (Hypervisor Call). When the hypervisor 20 requests the guest OS 65, it notifies by using an interrupt. The guest OS 65 accesses the virtual memory 62 as the physical memory of the virtual computer 60, but in reality, the address on the virtual memory 62 is converted into the address on the memory 32 of the host computer 10 by the CPU 31 and the hypervisor 20. To access the memory 32.

The virtual computer 70 also has the same configuration as the virtual computer 60, and includes a virtual CPU 71, a virtual memory 72, and a guest OS 75. The number of virtual machines (60, 70) on the hypervisor 20 may be three or more. The memory copy unit 21 copies the data of the memory 32 corresponding to the virtual memory 62 to the memory 32 corresponding to the virtual memory 72.

<< First embodiment: Data transmission by copying between virtual memories started by the receiving side virtual computer >>
FIG. 2 is a sequence diagram showing a flow of data transmission processing from the virtual machine 60 to the virtual machine 70, which is started by the virtual machine 70 on the receiving side according to the first embodiment. With reference to FIG. 2, the process in which the memory copy unit 21 of the hypervisor 20 copies the data in the virtual memory 62 of the virtual computer 60 to the virtual memory 72 of the virtual computer 70 will be described.

In step S101, a reception memory area, which is an area in which the virtual machine 70 on the receiving side receives data, is secured.
In step S102, the virtual machine 70 notifies the hypervisor 20 of the reception memory area using the HVC and requests data reception. Specifically, the virtual computer 70 sets the address and size of the received memory area in a specific register of the virtual CPU 71, and executes HVC for notifying the received memory area. The hypervisor 20 transfers the HVC to the memory copy unit 21 that executes the memory copy process.

In step S103, the memory copy unit 21 notifies the virtual machine 60 on the transmitting side that a transmission request has been made by using an interrupt.
In step S104, the virtual machine 60 in which the transmission request interrupt occurs secures a transmission memory area for storing transmission data.

In step S105, the virtual machine 60 sets transmission data in the transmission memory area.
In step S106, the virtual machine 60 sets the address and size of the transmission memory area in the register, notifies the transmission memory area, and executes HVC for requesting data transmission.

In step S107, the memory copy unit 21 copies data from the transmission memory area to the reception memory area. Specifically, the memory copy unit 21 copies the data on the memory 32 of the host computer 10 corresponding to the transmission memory area of the virtual computer 60 to the position (address) of the memory 32 corresponding to the reception memory area of the virtual machine 70. ..
In step S108, the memory copy unit 21 notifies the virtual machine 60 that the copy is completed by using an interrupt. The type (interrupt vector) is different between the interrupt in step S103 and the interrupt in step S108.

In step S109, the memory copy unit 21 notifies the virtual machine 70 that the copy has been completed by using an interrupt. After that, the virtual machine 70 can access the transmission data. The interrupt in step S108 and the interrupt in step S109 are of the same type (interrupt vector).
In the first embodiment, the memory copy is performed only once in step S107, and data can be transmitted from the virtual memory 62 of the virtual computer 60 to the virtual memory 72 of the virtual computer 70 at high speed.

<< Modification 1: Notification of copy completion using HVC response >>
In the first embodiment described above, the memory copy unit 21 uses an interrupt to notify the virtual machine 60 of the completion of copying (see step S108). Instead of the interrupt, the memory copy unit 21 may use the response (return value) of the HVC (see step S106) notifying the transmission memory area. Specifically, the memory copy unit 21 receives the notification of the transmission memory area by the HVC in step S106, subsequently executes the copy process of step S107, and notifies the virtual machine 60 of the copy completion as a response of the HVC of step S106. do.

<< Modification 2: Deformation Example 2: When the size of the transmission memory area is small >>
In the first embodiment, copying from the transmission memory area to the reception memory area is completed only once. When the transmission memory area of the virtual machine 60 on the transmission side is small and the data cannot be transmitted by one copy, the transmission data can be copied to the reception memory area by repeating steps S104 to S107.

In step S107 of the repeating process, the hypervisor 20 copies the current data to a position following the previously copied data in the received memory area.
In step S106, the virtual machine 60 on the transmitting side notifies the hypervisor 20 of the end of transmission by setting the size of the transmission memory area to 0. Upon receiving the notification of the completion of transmission, the hypervisor 20 finishes the iterative process without performing the process of step S107, and proceeds to step S108. The hypervisor 20 may proceed to step S109 instead of proceeding to step S108.

<< Modification of the first embodiment 3: When the size of the received memory area is small >>
When the virtual machine 70 on the receiving side does not know the size of the transmission data, the reception memory area is smaller than the transmission memory area, and the copy is not completed by one copy. In such a case, the memory copy unit 21 copies in a plurality of times.

FIG. 3 is a sequence diagram showing a flow of data transmission processing from the virtual machine 60 to the virtual machine 70 according to the third modification of the first embodiment. With reference to FIG. 3, when the received memory area is smaller than the transmitted memory area, the memory copy unit 21 of the hypervisor 20 divides the data in the virtual memory 62 of the virtual computer 60 into a plurality of times and uses the virtual computer 70. The process of copying to the virtual memory 72 will be described.

Steps S121 to S126 are the same as steps S101 to S106, respectively.
In step S127, the memory copy unit 21 copies data from the transmission memory area to the reception memory area to the transmission memory by the size of the reception memory.

In step S128, the memory copy unit 21 notifies the virtual machine 70 that the reception memory area is insufficient by using an interrupt.
Step S129 and step S130 are the same as step S101 and step S102, respectively.

In step S131, the memory copy unit 21 copies data from the next position copied in step S127 to the receive memory area in the transmission memory area. The size to be copied is the size of the area in which the copy has not been completed if the size of the area in the transmission memory area where the copy has not been completed is equal to or less than the size of the receive memory area. If not, the size to copy is the size of the receive memory area. In the following, the description will be continued on the assumption that the size of the area in the transmission memory area for which copying has not been completed is equal to or less than the size of the reception memory area.

Step S132 and step S133 are the same as those of step S108 and step S109, respectively.
In step S131, if the size of the area in the transmission memory area for which copying has not been completed is larger than the size of the reception memory area, the processes of steps S128 to S131 are repeated.

As described above, even when the reception memory area is smaller than the transmission memory area, data can be transmitted from the virtual memory 62 of the virtual computer 60 to the virtual memory 72 of the virtual computer 70. When data is transmitted using the network function, there is an upper limit to the size of one communication data (communication packet). If a reception memory area larger than this size is secured, data transmission can be performed at a higher speed than data transmission via a network.

In the third modification of the first embodiment described above, the memory copy unit 21 uses an interrupt to notify the virtual machine 70 of the completion of copying (see step S133). Instead of the interrupt, the memory copy unit 21 may use the response of the HVC (see step S130) notifying the received memory area. Specifically, when the memory copy unit 21 receives the notification of the received memory area by the HVC in step S130 and subsequently completes the copy process in step S131, the virtual computer 70 is notified of the copy completion as a reply from the HVC in step S130. Notice.

Further, in the modification 3 of the first embodiment described above, the memory copy unit 21 uses an interrupt to notify the virtual machine 70 of the lack of area (see step S128). Instead of the interrupt, the memory copy unit 21 may use the response of the HVC (see step S130) notifying the received memory area. Specifically, if the memory copy unit 21 receives the notification of the received memory area by the HVC in step S130, and subsequently the copy process in step S131 is not completed, the virtual computer 70 is notified of the lack of area as a reply from the HVC in step S130. Notice. Hereinafter, the virtual machine 70 and the memory copy unit 21 repeat steps S129 to S131.

<< Second embodiment: Data transmission by copying between virtual memories started by the transmitting virtual machine >>
FIG. 4 is a sequence diagram showing a flow of data transmission processing from the virtual machine 60 to the virtual machine 70, which is started by the virtual machine 60 on the transmitting side according to the second embodiment. With reference to FIG. 4, the process in which the memory copy unit 21 of the hypervisor 20 copies the data in the virtual memory 62 of the virtual computer 60 to the virtual memory 72 of the virtual computer 70 will be described.

Steps S201 to S203 are the same as steps S104 to S106 shown in FIG.
In step S204, the memory copy unit 21 notifies the virtual machine 70 on the receiving side of the reception request by using an interrupt.

Step S205 and step S206 are the same as step S101 and step S102 shown in FIG. 2, respectively.
Steps S207 to S209 are the same as steps S107 to S109 shown in FIG.

In the second embodiment, the memory copy process is performed only once in step S207, and data can be transmitted from the virtual memory 62 of the virtual computer 60 to the virtual memory 72 of the virtual computer 70 at high speed.

<< Modification 1: Notification of copy completion using HVC response >>
In the second embodiment described above, the memory copy unit 21 uses an interrupt to notify the virtual machine 70 of the completion of copying (see step S209). Instead of the interrupt, the memory copy unit 21 may use the response of the HVC (see step S206) notifying the received memory area. Specifically, the memory copy unit 21 receives the notification of the received memory area by the HVC in step S206, subsequently executes the copy process of step S207, and notifies the virtual machine 70 of the copy completion as a response of the HVC of step S206. do.

<< Modification 2: of the second embodiment: When the size of the received memory area is small >>
In the second embodiment described above, copying from the transmission memory area to the reception memory area is completed only once. When the reception memory area of the virtual machine 70 on the receiving side is small and the data cannot be transmitted by one copy executed in step S207, the same as steps S128 to S131 described in FIG. 3 following step S207. By repeating the process, the transmission data can be copied to the reception memory area. Further, the memory copy unit 21 may notify the virtual machine 70 of the lack of area by using the response of the HVC in step S130 instead of the interrupt in step S128.

Further, instead of the copy completion notification using the interrupt in step S209, the response of the HVC (see step S130) notifying the received memory area may be used. Specifically, when the memory copy unit 21 receives the notification of the received memory area by the HVC in step S130 and subsequently completes the copy process in step S131, the virtual computer 70 is notified of the copy completion as a reply from the HVC in step S130. Notice.

<< Third embodiment: Data transmission by changing the memory mapping >>
In the first and second embodiments, the hypervisor 20 copies data from the virtual memory 62 of the virtual computer 60 to the virtual memory 72 of the virtual computer 70, and transmits the data. Specifically, the hypervisor 20 copies data from the area of the memory 32 corresponding to the virtual memory 62 to the area of the memory 32 corresponding to the virtual memory 72. On the other hand, in the third embodiment, the hypervisor 20 changes the correspondence (memory mapping) between the virtual memory (62, 72) and the memory 32, thereby making the data copy unnecessary and transmitting the data.

FIG. 5 is a diagram showing the overall configuration of the host computer 10A according to the third embodiment. The hypervisor 20A includes a memory mapping unit 22 in place of the memory copy unit 21. Other configurations are the same as those of the host computer 10. The mapping (correspondence relationship) between the virtual memory (62, 72) and the memory 32 is managed by using the extended page table (41, 42, see FIG. 6) described later. The memory mapping unit 22 transmits data (memory page) from the virtual machine 60 to the virtual machine 70 by changing the extended page table (41, 42).

FIG. 6 is a diagram for explaining a state of mapping between the virtual memory of the virtual computer and the physical memory of the host computer according to the third embodiment. 100 and 300 on the left side of the virtual memory 62 of the virtual computer 60 shown in the upper left of FIG. 6 are the addresses of the virtual memory 62. It indicates that the transmission memory page corresponding to the transmission memory area starts from the address 300.

The extended page table 41 shown in the center of FIG. 6 is tabular data showing the correspondence between the page of the virtual memory 62 of the virtual computer 60 and the page of the memory 32, and is stored in the memory 32. The records (rows) of the extended page table are GPA (Guest Physical Address) 411, which is the logical address of the page constituting the virtual memory 62, and PA (Physical Address) 412, which is the physical address of the page constituting the memory 32. Includes attributes (columns). The GPA411 is a physical address when viewed from the virtual machine 60, but is a logical address (virtual physical address shown to the virtual machine 60) when viewed from the hypervisor 20A. In record 419, the transmission memory page of the virtual memory 62 having the GPA of 300 is mapped to the memory 32 having the PA of 440, and the data of the transmission memory page is the page of the memory 32 having the PA starting from 440 (FIG. 6). Indicates that it is stored in the host physical memory page). The same applies to record 418.

The extended page table 42 shown in the lower center of FIG. 6 is tabular data showing the correspondence between the page of the virtual memory 72 of the virtual computer 70 and the page of the memory 32, and is the extended page table 41 of the virtual computer 60. It has a similar configuration. Record 429 indicates that the page of virtual memory 72 with a GPA of 420 is mapped to the page of memory 32 with a PA of 900.

FIG. 7 is a sequence diagram showing a flow of data transmission processing by changing the memory mapping from the virtual machine 60 to the virtual machine 70 according to the third embodiment. With reference to FIG. 7, the memory mapping unit 22 of the hypervisor 20A transmits data by changing the memory mapping between the page on the virtual memory 62 of the virtual computer 60 and the page of the virtual memory 72 of the virtual computer 70. The process to be realized will be explained.

In step S301, a transmission memory page, which is an area in which the virtual machine 60 on the transmitting side transmits data, is secured. FIG. 6 shows the state of the memory mapping at this time, and the memory page of the virtual memory 62 starting from the address 300 of the virtual computer 60 is mapped to the memory page of the memory 32 starting from the address 440 of the host computer 10A. Indicates that you are.

In step S302, the virtual machine 60 sets transmission data in the transmission memory page. The set data is stored in the memory page of the memory 32 starting from the address 440.
In step S303, the virtual machine 60 notifies the hypervisor 20 of the transmission memory page using the HVC and requests data transmission. Specifically, the virtual computer 60 sets the address of the transmission memory page in a specific register of the virtual CPU 61, and executes HVC for notifying the transmission memory page and requesting data transmission. The hypervisor 20 transfers the HVC to the memory mapping unit 22 that executes the memory mapping change process.

In step S304, the memory mapping unit 22 notifies the virtual machine 70 on the receiving side of the reception request by using an interrupt.

In step S305, the virtual machine 70 in which the reception request interrupt occurs secures the reception memory page. FIG. 8 is a diagram showing a state of mapping between the virtual memory of the virtual computer and the physical memory of the host computer at the time when the virtual computer 70 secures the received memory page according to the third embodiment. As shown by record 428 of the extended page table 42 of the virtual computer 70, the received memory page starting from the address 120 on the virtual memory 72 is a page starting from the address 700 on the memory 32 (described as the host physical memory page in FIG. 8). It is mapped to.

In step S306, the virtual machine 70 sets the address of the received memory page in a specific register and executes HVC for notifying the received memory page.

In step S307, the memory mapping unit 22 changes the memory mapping. Specifically, the memory mapping unit 22 performs the following processing. (1) A new memory page is secured on the memory 32. (2) The PA412 of the record 419 corresponding to the transmission memory page of the extended page table 41 of the virtual computer 60 is changed to the physical address of the memory page secured in (1). (3) The PA422 of the record 428 corresponding to the received memory page of the extended page table 42 of the virtual computer 70 is changed to the physical address to which the logical address of the transmitted memory page before the change in (2) is mapped. FIG. 9 is a diagram showing a state of mapping between the virtual memory of the virtual computer and the physical memory of the host computer at the time when the memory mapping is changed according to the third embodiment. Compared to FIG. 8, the PA412 of the record 419 is changed from 440 to 340, and the PA422 of the record 428 is changed from 700 to 440. The receive memory page has been modified to map to the page starting at address 440 to which the transmit memory page was mapped.

In step S308, the memory mapping unit 22 notifies the virtual machine 60 that the mapping change is completed by using an interrupt.
In step S309, the memory mapping unit 22 notifies the virtual machine 70 that the mapping change is completed by using an interrupt.

In the third embodiment, the page of the memory 32 of the host computer 10A accessed by the virtual computer 60 is switched to the page accessed by the virtual computer 70, so that data is transmitted from the virtual computer 60 to the virtual computer 70. .. There is no memory copy, and data can be transmitted at high speed. Further, the memory is not shared, and the data of the virtual machine 70 on the receiving side is not accessed from the virtual machine 60 on the transmitting side.

<< Modification 1: Notification of copy completion using HVC response >>
In the third embodiment described above, the memory mapping unit 22 uses an interrupt to notify the virtual machine 70 that the mapping change is completed (see step S309). Instead of the interrupt, the memory mapping unit 22 may use the response of the HVC (see step S306) notifying the received memory page. Specifically, the memory mapping unit 22 receives the notification of the received memory page by the HVC in step S306, subsequently executes the memory mapping change process of step S307, and virtualizes the completion of the mapping change as a response of the HVC of step S306. Notify the computer 70.

<< Modification 2: Data transmission by changing memory mapping using a plurality of pages >>
In the third embodiment described above, the number of pages to be transmitted is one, but a plurality of pages may be used. FIG. 10 is a sequence diagram showing a flow of data transmission processing by changing the mapping of a plurality of memory pages between the virtual machine 60 and the virtual machine 70 according to the second modification of the third embodiment.

In step S321, the virtual machine 60 on the transmitting side secures a plurality of continuous transmission memory pages which are areas for transmitting data.
In step S322, the virtual machine 60 sets transmission data in the transmission memory page.

In step S323, the virtual machine 60 notifies the hypervisor 20 of the transmission memory page using the HVC and requests data transmission. Specifically, the virtual computer 60 sets the address and the number of pages of the transmission memory page in a specific register of the virtual CPU 61, and executes HVC for notifying the transmission memory page. The hypervisor 20 transfers the HVC to the memory mapping unit 22 that executes the memory mapping change process.

In step S324, the memory mapping unit 22 notifies the virtual machine 70 on the receiving side of the reception request by using an interrupt.
In step S325, the virtual machine 70 in which the interrupt has occurred secures a received memory page. The virtual machine 70 may secure a plurality of consecutive received memory pages.

In step S326, the virtual computer 70 sets the address of the received memory memory and the number of pages in a specific register, and executes HVC for notifying the received memory page. The memory mapping unit 22 compares the number of pages of the transmission memory page with the number of pages of the reception memory page. Here, the description will be continued assuming that the number of pages of the transmission memory page and the number of pages of the reception memory page are different. If they are the same, the process proceeds to step S329.

The memory mapping unit 22 returns the number of pages of the transmission memory page in response to the HVC.
In step S327, the virtual machine 70 secures a continuous reception memory page with the number of pages corresponding to the response of the HVC.

In step S328, the virtual computer 70 sets the address of the received memory memory and the number of pages in the register, and executes HVC for notifying the received memory page.
In step S329, the memory mapping unit 22 changes the memory mapping. Specifically, the memory mapping unit 22 changes the PA412 of the record of the transmission memory page of the extended page table 41 for the virtual computer 60 on the transmission side to the address of the new memory page on the receiving side, as in step S307. The PA422 of the record of the received memory page of the extended page table 42 for the virtual computer 70 is changed to the address of the page on the memory 32 to which the transmitted memory page is mapped. The memory mapping unit 22 changes PA422 of a plurality of records in the extended page table 42 so that the continuous original transmission memory page is mapped to the continuous reception memory page.

In step S330, the memory mapping unit 22 notifies the virtual machine 60 that the mapping change is completed by using an interrupt.
In step S331, the memory mapping unit 22 notifies the virtual machine 70 that the mapping change is completed by using an interrupt.

In the second modification of the third embodiment described above, the memory mapping unit 22 uses an interrupt to notify the virtual machine 70 that the mapping change is completed (see step S331). Instead of the interrupt, the memory mapping unit 22 may use the response of the HVC (see step S328) notifying the received memory page. Specifically, the memory mapping unit 22 receives the notification of the received memory page by the HVC in step S328, subsequently executes the memory mapping change process of step S329, and virtualizes the completion of the mapping change as a response of the HVC of step S328. Notify the computer 70.

<< Fourth Embodiment: Data transmission by copying between virtual memories with information flow control >>
In the first to third embodiments, data is transmitted from the virtual machine 60 to the virtual machine 70. On the contrary, it is also possible to transmit from the virtual machine 70 to the virtual machine 60, and communication in both directions is possible. However, depending on the sensitivity of the information held by the virtual machine (60, 70) and the application of the virtual machine (60, 70), it may be desired to limit the communication to only one direction.

For example, when the virtual machine 70 processes high-density information and the virtual machine 60 processes general-level information, the virtual machine 60 is prohibited from transmitting data from the virtual machine 70 to the virtual machine 60. It is possible to prevent leakage of highly sensitive information. In addition, regardless of the high level of sensitivity, computers running dangerous programs such as malware should be dedicated to reception and data transmission should not be possible so that malware will not spread to other computers. can. The following describes data transmission by copying between virtual memories in which the direction of data transmission is restricted.

FIG. 11 is a diagram illustrating a data structure of the virtual machine database 51 stored on the storage 33 according to the fourth embodiment. The virtual machine database 51 is tabular data, one record (row) represents one virtual machine (60, 70), and the attributes (columns) of the virtual machine ID 511, hardware setting 512, and authentication information 513 are displayed. include.

The virtual machine ID 511 is identification information (ID, Identifire) of the virtual machines (60, 70).
The hardware setting 512 is the hardware setting information of the virtual computer (60, 70), and is the number of cores of the virtual CPU (61, 71), the size of the virtual memory (62, 72), and the virtual NIC (not shown). The MAC (Media Access Control) address, information indicating an area allocated to the virtual storage (not shown) of the virtual computer (60, 70) in the area (sector) of the storage 33, and the like are included.

The authentication information 513 is authentication information of the record and its contents, and is a hash value or a digital signature of the virtual computer ID 511 and the hardware setting 512. The authentication information 513 may be a hash value or a digital signature of data including the boot loader on the virtual storage, the kernel of the guest OS (65, 75), and the like, in addition to the virtual computer ID 511 and the hardware setting 512.

Before the virtual machine (60, 70) starts, the hypervisor (20, 20A) matches the hardware settings, boot loader, and guest OS kernel with the hash value or digital signature of authentication information 513, and the matching fails. In that case, the start of the virtual computer (60, 70) is stopped.

Record 519 indicates that the number of cores of the virtual CPU of the virtual computer whose virtual computer ID 511 is "VM # 60" is 1, and the MAC address of the virtual NIC starts with "3F34".

FIG. 12 is a diagram illustrating a data structure of the information flow control management database 52 stored on the storage 33 according to the fourth embodiment. The information flow control management database 52 is tabular data, one record (row) indicates the direction of data transmission between permitted virtual computers, and the attributes (columns) of the source 521 and the destination 522 are set. include. The source 521 is the virtual computer ID 511 of the virtual computer which is the data transmission source in the permitted data transmission direction, and the transmission destination 522 is the virtual computer ID 511 of the virtual computer which is the data transmission destination in the permitted data transmission direction.

Record 529 indicates that data can be transmitted from "VM # 60" to "VM # 70". The information flow control management database 52 includes only permitted data transmission directions and does not include unauthorized data transmission directions.

FIG. 13 is a sequence diagram showing a flow of data transmission processing from the virtual machine 60 to the virtual machine 70 with information flow control according to the fourth embodiment. With reference to FIG. 13, the process in which the memory copy unit 21 of the hypervisor 20 copies the data in the virtual memory 62 of the virtual computer 60 to the virtual memory 72 of the virtual computer 70 will be described.

Steps S401 to S403 are the same as steps S201 to S203 shown in FIG. 4, respectively.
In step S404, the memory copy unit 21 to which the HVC of step S403 is transferred from the hypervisor 20 determines whether data can be transmitted to the virtual computer 70 by referring to the information flow control management database 52. Specifically, the memory copy unit 21 searches for a record in which the source 521 is the virtual machine ID of the virtual machine 60 and the destination 522 is the virtual machine ID of the virtual machine 70. Subsequently, the memory copy unit 21 determines that transmission is possible if the record exists and proceeds to step S406, and if the record does not exist, determines that transmission is not possible and proceeds to step S405.

In step S405, the memory copy unit 21 notifies the virtual machine 60 that transmission is not possible by using an interrupt. An interrupt occurs in the virtual machine 60, and the data transmission process ends.
Steps S406 to S411 are the same as steps S204 to S209 shown in FIG. 4, respectively.

By doing so, the record exists in the information flow control management database 52, and the data can be transmitted only from the virtual machine of the permitted source 521 to the virtual machine of the destination 522. Data transmission from the virtual machine of the source 521 to the virtual machine of the destination 522, for which no record exists in the information flow control management database 52, is prohibited.

In the fourth embodiment, the memory copy unit 21 determines whether or not data transmission is possible in step S404. Unlike this, the memory copy unit 21 may determine whether or not the data can be transmitted before copying the data, for example, after the HVC notifying the received memory area in step S408.

If the memory copy unit 21 determines in step S404 that transmission is not possible, it notifies the virtual machine 60 using an interrupt in step S405. Instead of the interrupt, the memory copy unit 21 may use the response of the HVC (see step S403) notifying the transmission memory area. Specifically, the memory copy unit 21 receives a notification of the transmission memory area by the HVC in step S403, and subsequently, if transmission is not possible in step S404, notifies the virtual machine 60 that transmission is not possible as a reply from the HVC in step S403. do.

<< Fifth Embodiment: Data transmission by changing memory mapping accompanied by information flow control >>
Even in the data transmission by changing the memory mapping, the data transmission direction can be restricted as in the fourth embodiment. Similar to the fourth embodiment, the virtual computer database 51 (see FIG. 11) and the information flow control management database 52 (see FIG. 12) are stored in the storage 33.

FIG. 14 is a sequence diagram showing a flow of data transmission processing by changing the memory mapping from the virtual machine 60 to the virtual machine 70 with information flow control according to the fifth embodiment. With reference to FIG. 14, the memory mapping unit 22 of the hypervisor 20A transmits data by changing the memory mapping between the page on the virtual memory 62 of the virtual computer 60 and the page of the virtual memory 72 of the virtual computer 70. The process to be realized will be explained.

Steps S501 to S503 are the same as steps S301 to S303 shown in FIG. 7.
In step S504, the memory mapping unit 22 to which the HVC of step S503 is transferred from the hypervisor 20A determines whether data can be transmitted to the virtual computer 70 by referring to the information flow control management database 52. Specifically, the memory mapping unit 22 searches for a record in which the source 521 is the virtual machine ID of the virtual machine 60 and the destination 522 is the virtual machine ID of the virtual machine 70. Subsequently, the memory mapping unit 22 determines that transmission is possible if the record exists, and proceeds to step S506. If the record does not exist, the memory mapping unit 22 determines that transmission is not possible and proceeds to step S505.

In step S505, the memory mapping unit 22 notifies the virtual machine 60 that transmission is not possible by using an interrupt. An interrupt occurs in the virtual machine 60, and the data transmission process ends.
Steps S506 to S511 are the same as steps S304 to S309 described in FIG. 7.

By doing so, the record exists in the information flow control management database 52, and the data can be transmitted only from the virtual machine of the permitted source 521 to the virtual machine of the destination 522. Data transmission from the virtual machine of the source 521 to the virtual machine of the destination 522, for which no record exists in the information flow control management database 52, is prohibited.

In the fifth embodiment, the memory mapping unit 22 determines whether or not data transmission is possible in step S504. Unlike this, the memory mapping unit 22 may determine whether or not to transmit data before changing the memory mapping, for example, after the HVC notifying the received memory page in step S508.
If the memory mapping unit 22 determines in step S504 that transmission is not possible, the virtual machine 60 is notified by using an interrupt in step S505. Instead of the interrupt, the memory mapping unit 22 may use the response of the HVC (see step S503) notifying the transmission memory page.

≪Variation example≫
In the above-described embodiment, the HVC parameter for notifying the hypervisor (20, 20A) of the transmission memory area, the reception memory area, and the like by the virtual computer (60, 70) is set in a specific register. Parameters may be stored in memory and the address of the memory may be set in a specific register. Further, the hypervisor (20, 20A) stores the result at the time of HVC completion such as insufficient area in the memory, the number of pages of the transmission memory page (see step S326 in FIG. 10), copy completion, and the copied memory size. You may do it.

Further, when the hypervisor (20, 20A) notifies the virtual machine (60, 70) of a transmission request, a reception request, or the like, the notification is made using each type of interrupt (interrupt vector). There is only one type of interrupt (interrupt vector), and the type of notification such as a transmission request or a reception request may be notified via a specific register as an interrupt parameter. Alternatively, the notification type may be stored in a memory and the address of the memory may be set in a specific register. Further, the virtual machine (60, 70) may acquire the immediately preceding interrupt type by using the HVC.

In the above-described embodiment, the receiving-side virtual machine 70 receives the data transmitted by the transmitting-side virtual machine 60 as it is. Instead of transmitting and receiving data as it is, the hypervisor 20 may convert the data so that the virtual machine 70 receives the data. Examples of conversions include, but are not limited to, encryption, decryption, endian (byte order) conversion, data compression, data decompression, encoding, decoding and combinations thereof. The key required for encryption or decryption may be made accessible only to the hypervisor 20, and may be exclusively encrypted or decrypted by the hypervisor 20. If the virtual machine (60, 70) is connected to an external network such as the Internet and there is a risk of being attacked from the outside or infected with malware, do not put the key on the virtual machine (60, 70). This makes it possible to ensure the security of the data.

In the third modification of the first embodiment shown in FIG. 3, the hypervisor 20 notifies the virtual machine 70 on the receiving side of the shortage of the received memory area and the completion of copying by using an interrupt (step S128 and step S133). reference). Instead of the interrupt, the hypervisor 20 may notify using a specific part of the received memory area. For example, if the first byte of the received memory area is 1, the received memory area is insufficient, and if it is 2, the copy is completed, and the hypervisor 20 may notify the virtual machine 70. In this case, the data is copied after the second byte. In other embodiments and modifications, the hypervisor 20 may notify the virtual machines (60, 70) of a transmission request, a reception request, copy completion, and the like via a specific portion of the memory area.

In the above embodiment, the transmitting side is fixed to the virtual machine 60, and the receiving side is fixed to the virtual machine 70. The virtual machine (60, 70) may be able to specify a communication partner. For example, in the second embodiment shown in FIG. 4, the virtual machine 60 on the transmitting side may be able to specify the virtual machine on the receiving side. As a method of designation, a virtual machine on the receiving side may be designated as a parameter of the HVC (step S203) for notifying the transmission memory area. In this case, the hypervisor 20 notifies the receiving side virtual machine of the receiving side virtual machine via the parameters of the reception request interrupt (step S204), the interrupt type (interrupt vector), and the specific part of the receiving memory area. You may try to do it.

Further, the virtual machine 70 on the receiving side may be able to specify a communication partner. In the first embodiment shown in FIG. 2, the virtual machine 70 may set the virtual machine on the transmitting side in the parameter of the HVC (step S102) for notifying the received memory area or in a specific part of the received memory area.

In the above-described embodiment and its modification, there is one virtual machine on the transmitting side and one virtual machine on the receiving side. On the other hand, one transmitting virtual machine may be able to transmit data to a plurality of virtual machines. In the data transmission by the memory copy in the second embodiment, the memory copy unit 21 copies the data from the transmission memory area to each reception memory area of the plurality of receiving virtual machines. Further, in the data transmission by changing the memory mapping in the third embodiment, the memory mapping unit 22 maps the received memory page of each of the plurality of receiving virtual computers to the host physical memory page corresponding to the transmitted memory page before the change. do.

In the above-described embodiment and its modification, the guest OS (65, 75) is running on the virtual computer (60, 70), and the application is running on it. Even if there is no guest OS and the application runs directly on the virtual machine (60, 70), the application executes HVC and processes the interrupt to transmit the data set in the virtual memory (62, 72). can do.

≪Effect≫
The hypervisor 20 of the first and second embodiments realizes data transmission from the virtual machine 60 to the virtual computer 70 by copying data from the transmission memory area on the memory 32 to the reception memory area. The number of data copies is reduced compared to conventional data transmission, and high-speed transmission is possible. When the hypervisor 20A of the third embodiment changes the memory mapping and transmits the data, the data is not copied and can be transmitted at a higher speed.

In the fourth and fifth embodiments, the data transmission direction is limited to one direction, and it is possible to prevent the leakage of highly sensitive information and dangerous data such as malware.

10,10A Host calculator 20 Hypervisor 21 Memory copy unit 22 Memory mapping unit 31 CPU
32 Memory 41, 42 Extended page table 51 Virtual computer database 52 Information flow control management database 60 (sender) Virtual computer 61, 71 Virtual CPU
62,72 Virtual memory 70 (Receiving side) Virtual computer

Claims (5)

A hypervisor that operates multiple virtual computers on a physical computer and mediates data communication between the virtual computers.
Upon receiving a notification of the transmission memory area from the transmitting side virtual machine which is the data transmitting side of the virtual machine, the receiving side virtual machine which is the data receiving side of the virtual machine is interrupted to notify the reception request.
A hypervisor having a memory copy unit that copies data in the transmission memory area to the reception memory area when the reception side virtual computer notifies the reception memory area.
Hypervisor program to make it work. A hypervisor that operates multiple virtual computers on a physical computer and mediates data communication between the virtual computers.
When the receiving memory area is notified from the receiving side virtual machine which is the data receiving side of the virtual machine, the transmitting request is interrupted and notified to the transmitting side virtual machine which is the data transmitting side of the virtual machine.
A hypervisor having a memory copy unit that copies data in the transmission memory area to the reception memory area when notified of the transmission memory area from the transmission side virtual computer.
Hypervisor program to make it work. The memory copy unit is
The data in the transmission memory area is subjected to conversion processing of any one or a plurality of combinations of encryption, decryption, endian conversion, data compression, data decompression, encoding and decoding, and the data after this conversion processing. To the received memory area,
The hypervisor program according to claim 1 or 2. A hypervisor that operates multiple virtual computers on a physical computer and mediates data communication between the virtual computers.
The virtual machine operates on a logical address managed by the hypervisor and mapped to a physical address.
The hypervisor is
When the transmission memory page is notified from the transmitting side virtual computer which is the data transmitting side of the virtual computer, and the receiving memory page is notified from the receiving side virtual computer which is the data receiving side of the virtual computer, the above-mentioned The physical address of the logical address mapping destination of the receive memory page is changed to the physical address of the mapping destination of the logical address of the transmission memory page, and the physical address of the mapping destination of the logical address of the transmission memory page is changed to another physical address. Hypervisor with memory mapping to change,
Hypervisor program to make it work. The hypervisor is
Notifying the completion of transmission / reception by interrupting the transmitting side virtual machine and the receiving side virtual machine.
The hypervisor program according to any one of claims 1 to 4.

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