CN107368353A - A kind of method and apparatus for realizing virutal machine memory heat addition - Google Patents

Abstract

The embodiment of the invention discloses a kind of method and apparatus for realizing virutal machine memory heat addition, methods described includes：Virutal machine memory heat addition is carried out according to the memory size of each node in virtual machine；After virutal machine memory heat is added successfully, the memory information and the current memory information of the virtual machine that are preserved in database are updated by the source code for changing virtual machine manager, to keep the consistent of the current memory information of the memory information and virtual machine preserved in the database.The embodiment of the present invention can effectively increase the application scenarios of virtual machine (vm) migration function, reduce migration limitation.

Description

A method and device for realizing hot addition of virtual machine memory

technical field

The invention relates to virtual machine technology, in particular to a method and device for realizing hot addition of virtual machine memory.

Background technique

To upgrade the configuration of a traditional server, it often needs to be shut down; in a virtualized environment, it is easier to upgrade the configuration online, both technically and operationally, so that customers can still upgrade the configuration when the server load exceeds the estimate. Ability to guarantee service availability. The Linux kernel has implemented memory hot-swapping support. When a Linux system runs in a physical or virtual environment, as long as the host can provide a memory hot-swapping mechanism, the Linux kernel can increase or decrease memory accordingly. Combined with the technology of the open source emulator qemu memory and CPU hot swap, it can realize the online system upgrade without interrupting the business in the production environment. If the application programming interface (Application Programming Interface, API) provided by the open source emulator qemu is directly called to perform memory hot plugging, the C function library libvirt cannot perceive each addition, and cannot open a virtual machine (Virtual Machine, VM). snapshot and migrate.

Contents of the invention

In order to solve the above-mentioned technical problems, the embodiments of the present invention provide a method and an apparatus for realizing hot addition of memory of a virtual machine, which can be adopted.

In order to achieve the purpose of the present invention, on the one hand, the embodiment of the present invention provides a method for realizing hot addition of virtual machine memory, including:

According to the memory size of each node in the virtual machine, perform hot addition of virtual machine memory; after the hot addition of virtual machine memory is successful, the memory information stored in the database and the current memory of the virtual machine are compared by modifying the source code of the virtual machine manager The information is updated to keep the memory information stored in the database consistent with the current memory information of the virtual machine.

Compared with the prior art, the embodiment of the present invention performs virtual machine memory hot addition according to the memory size of each node in the virtual machine; after the virtual machine memory hot addition succeeds, the source code of the virtual machine manager is modified to save The memory information of the virtual machine and the current memory information of the virtual machine are updated to keep the memory information saved in the database consistent with the current memory information of the virtual machine. The embodiment of the present invention can effectively increase the application scenarios of the virtual machine migration function, and reduce migration restrictions.

Further, the virtual machine is created using an open source simulator qemu;

The virtual machine manager is a virtualization tool libvirt.

Further, the hot adding of virtual machine memory according to the memory size of each node in the virtual machine includes:

Obtain the non-uniform memory access numa node topology information of the virtual machine;

If it is learned that there is only one numa node in the virtual machine according to the numa node topology information, then directly perform memory hot addition; if it is learned that there are multiple numa nodes in the virtual machine according to the numa node topology information, then obtain the minimum memory numa nodes, and hot add memory to the numa node with the smallest memory.

Further, updating the memory information stored in the database and the current memory information of the virtual machine by modifying the source code of the virtual machine manager includes:

The virtual machine is managed by calling a kernel-based kvm virtualization interface;

By modifying the source code of the virtualization tool libvirt, the memory information in the Extensible Markup Language XML is updated.

Further, the hot adding of virtual machine memory includes:

The Libvirt sends the memory hot-add event to qemu through the socket;

The qemu performs memory hot-add according to the memory hot-add event;

After performing the memory hot-add, it also includes:

If the execution of the memory hot addition fails, a processing result is returned through libvirt; if the execution of the memory hot addition is successful, the memory information in the XML of the virtual machine is updated.

On the other hand, the embodiment of the present invention also provides an apparatus for implementing virtual machine memory hot addition, including:

The management module is used to perform virtual machine memory hot addition according to the memory size of each node in the virtual machine; after the virtual machine memory hot addition is successful, the memory information stored in the database and the memory information stored in the database are modified by modifying the source code of the virtual machine manager. The current memory information of the virtual machine is updated to keep the memory information stored in the database consistent with the current memory information of the virtual machine.

Further, the device also includes:

The virtual machine is created using the open source emulator qemu;

The virtual machine manager is a virtualization tool libvirt.

Further, the device also includes:

An acquisition module, configured to acquire the non-uniform memory access numa node topology information of the virtual machine;

An execution module, configured to directly perform memory hot-add if it is learned that there is only one numa node in the virtual machine according to the numa node topology information; if it is learned that there are multiple numa nodes in the virtual machine according to the numa node topology information , the numa node with the smallest memory is obtained, and memory hot-add is performed on the numa node with the smallest memory.

Further, the management module is also used for:

The virtual machine is managed by calling a kernel-based kvm virtualization interface;

By modifying the source code of the virtualization tool libvirt, the memory information in the Extensible Markup Language XML is updated.

Further, the management module is also used for:

The Libvirt sends the memory hot-add event to qemu through the socket;

The qemu performs memory hot-add according to the memory hot-add event;

After performing the memory hot-add, it also includes:

If the execution of the memory hot addition fails, a processing result is returned through libvirt; if the execution of the memory hot addition is successful, the memory information in the XML of the virtual machine is updated.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Description of drawings

The accompanying drawings are used to provide a further understanding of the technical solution of the present invention, and constitute a part of the description, and are used together with the embodiments of the application to explain the technical solution of the present invention, and do not constitute a limitation to the technical solution of the present invention.

FIG. 1 is a flow chart of a method for implementing hot addition of virtual machine memory according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a method for realizing hot addition of virtual machine memory according to an embodiment of the present invention;

FIG. 3 is a structural diagram of an apparatus for realizing hot addition of memory of a virtual machine according to an embodiment of the present invention.

detailed description

In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined arbitrarily with each other.

The steps shown in the flowcharts of the figures may be performed in a computer system, such as a set of computer-executable instructions. Also, although a logical order is shown in the flowcharts, in some cases the steps shown or described may be performed in an order different from that shown or described herein.

As shown in Figure 1, it is a flow chart of a method for implementing virtual machine memory hot addition in an embodiment of the present invention. This embodiment includes the following steps:

Step 100: performing virtual machine memory hot addition according to the memory size of each node in the virtual machine;

Step 101: After the virtual machine memory hot addition is successful, update the memory information stored in the database and the current memory information of the virtual machine by modifying the source code of the virtual machine manager, so as to keep the memory stored in the database The information is consistent with the current memory information of the virtual machine.

Specifically, the embodiment of the present invention is a virtualization product based on qemu and libvirt to realize hot addition of virtual machine memory, support migration and snapshot method. Call the API provided by the open source emulator qemu to perform memory hot plugging. To take a snapshot and migrate the virtual machine VM, you need to call the API of libvirt to implement each hot plugging. For memory hot plugging, the C function library libvirt must be aware of each addition, which must be reflected in the eXtensible Markup Language (XML).

In general, virtual machines in qemu are created through Libvirt. To support memory hot swap, you need to specify the maximum memory maxMemory configuration when creating a virtual machine, and you need to specify at least one non-uniform memory access (numa) node, which It is the numa node in the virtual machine, not the node in the host machine. When there are multiple numa nodes, when performing memory hot plugging, it will involve the issue of which node to add memory to, and how to keep the memory size consistent between each node.

The embodiment of the present invention adopts libvirt to update the memory and currentmemory in the XML after executing the memory hot plug, so that the information stored in the database is consistent with the real memory size of the VM.

The embodiment of the present invention adopts C language to carry out the realization of virtual machine memory hot adding method, uses open source emulator qemu to create virtual machine, uses libvirt to call kvm virtualization interface to manage virtual machine, by modifying libvirt source code to come to XML The memory information is updated to ensure the consistency of the virtual machine XML data saved in the libvirt and qemu processes after the hot memory addition, and the balance of the memory size among the various node nodes in the VM.

Among them, Kernel-based Virtual Machine (KVM) is a full-featured virtualization solution on the x86 hardware platform under Linux.

The virtual machine manager is a virtualization tool libvirt. libvirt is a set of free and open-source C function libraries that support mainstream virtualization tools under Linux. It aims to provide a set of convenient and reliable programming interfaces for various virtual machine monitoring programs such as qemu.

The method of the embodiment of the present invention improves the memory hot adding function, can effectively increase the usage scenarios of the virtual machine migration function, and reduce migration restrictions. At the same time, this method can facilitate the upgrade and maintenance of virtualization products in the later stage through the modification of the software part.

The embodiment of the present invention performs virtual machine memory hot-add according to the memory size of each node in the virtual machine; after the virtual machine memory hot-add is successful, the memory information stored in the database and the virtual The current memory information of the virtual machine is updated to keep the memory information stored in the database consistent with the current memory information of the virtual machine. The embodiment of the present invention can effectively increase the application scenarios of the virtual machine migration function, and reduce migration restrictions.

The specific implementation process of the method in the embodiment of the present invention is as follows: modify the libvirt source code to update the memory information in the XML to ensure the consistency of the virtual machine XML data stored in the libvirt and qemu processes after the hot addition of memory, and the consistency of each virtual machine XML data in the VM. The balance of memory size between node nodes.

Further, the hot addition of virtual machine memory according to the memory size of each node in the virtual machine includes:

Obtain the non-uniform memory access numa node topology information of the virtual machine;

If it is learned that there is only one numa node in the virtual machine according to the numa node topology information, then directly perform memory hot addition; if it is learned that there are multiple numa nodes in the virtual machine according to the numa node topology information, then obtain the minimum memory numa nodes, and hot add memory to the numa node with the smallest memory.

Further, updating the memory information stored in the database and the current memory information of the virtual machine by modifying the source code of the virtual machine manager includes:

The virtual machine is managed by calling a kernel-based kvm virtualization interface;

By modifying the source code of the virtualization tool libvirt, the memory information in the Extensible Markup Language XML is updated.

Further, the hot adding of virtual machine memory includes:

The Libvirt sends the memory hot-add event to qemu through the socket;

The qemu performs memory hot-add according to the memory hot-add event;

After performing the memory hot-add, it also includes:

If the execution of the memory hot addition fails, a processing result is returned through libvirt; if the execution of the memory hot addition is successful, the memory information in the XML of the virtual machine is updated.

Fig. 2 is a schematic diagram of a method for realizing hot addition of virtual machine memory according to an embodiment of the present invention, as shown in Fig. 2:

Specifically, the code implementation mainly includes the following steps:

Step 201: Obtain the numa topology information of the virtual machine. If there is only one numa node, perform memory hot-add directly; if there are multiple nodes, take out the node node with the smallest memory, and perform memory hot-add on it.

Step 202: Libvirt sends the memory hot-plug event to qemu through the socket, and qemu executes the memory hot-add, if the execution fails, then directly jump to step 204; if successful, then proceed to the following step 203 for processing.

Step 203: update the memory information in the virtual machine xml, memory after memory hot plugging=memory before memory hot plugging+memory after memory hot plugging.

Step 204: libvirt returns the processing result.

The embodiment of the present invention proposes a libvirt-based method for realizing hot addition of virtual machine memory, and supports migration and snapshot at the same time. By modifying the libvirt source code, the memory information in the XML is updated after each memory is successfully added to keep the database and VM information consistent, and at the same time realize the snapshot and migration of the virtual machine after memory hot plugging. Through the re-development of libvirt source code, the memory hot-swapping function is further improved, and the competitiveness of virtualization products is improved. By designing a reasonable memory hot-add method, without affecting the original functions, the memory hot-add function is further improved according to new requirements, and the application scenarios of the virtual machine migration function are added.

FIG. 3 is a structural diagram of a device for implementing hot addition of virtual machine memory according to an embodiment of the present invention. As shown in FIG. 3 , another aspect of the embodiment of the present invention provides a device for implementing hot addition of virtual machine memory, including:

The management module 300 is configured to perform virtual machine memory hot-add according to the memory size of each node in the virtual machine; after the virtual machine memory hot-add is successful, modify the source code of the virtual machine manager to modify the memory information stored in the database and all The current memory information of the virtual machine is updated to keep the memory information stored in the database consistent with the current memory information of the virtual machine.

Further, the device also includes:

The virtual machine is created using the open source emulator qemu;

The virtual machine manager is a virtualization tool libvirt.

Further, the device also includes:

An acquisition module 301, configured to acquire the non-uniform memory access numa node topology information of the virtual machine;

The execution module 302 is configured to directly perform memory hot-adding if it is learned that there is only one numa node in the virtual machine according to the numa node topology information; if it is learned that there are multiple numa nodes in the virtual machine according to the numa node topology information node, obtain the numa node with the smallest memory, and perform memory hot-add on the numa node with the smallest memory.

Further, the management module 300 is also used for:

The virtual machine is managed by calling a kernel-based kvm virtualization interface;

By modifying the source code of the virtualization tool libvirt, the memory information in the Extensible Markup Language XML is updated.

Further, the management module 300 is also used for:

The Libvirt sends the memory hot-add event to qemu through the socket;

The qemu performs memory hot-add according to the memory hot-add event;

After performing the memory hot-add, it also includes:

If the execution of the memory hot addition fails, a processing result is returned through libvirt; if the execution of the memory hot addition is successful, the memory information in the XML of the virtual machine is updated.

Although the embodiments disclosed in the present invention are as above, the described content is only an embodiment adopted for understanding the present invention, and is not intended to limit the present invention. Anyone skilled in the field of the present invention can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed by the present invention, but the patent protection scope of the present invention must still be The scope defined by the appended claims shall prevail.

Claims (10)

1. A method for realizing hot addition of virtual machine memory, characterized in that, comprising: According to the memory size of each node in the virtual machine, perform hot addition of virtual machine memory; after the hot addition of virtual machine memory is successful, the memory information stored in the database and the current memory of the virtual machine are compared by modifying the source code of the virtual machine manager The information is updated to keep the memory information stored in the database consistent with the current memory information of the virtual machine. 2. the method for realizing virtual machine memory hot addition according to claim 1, is characterized in that, The virtual machine is created using the open source emulator qemu; The virtual machine manager is a virtualization tool libvirt. 3. The method for realizing hot addition of virtual machine memory according to claim 2, wherein the hot addition of virtual machine memory according to the memory size of each node in the virtual machine comprises: Obtain the non-uniform memory access numa node topology information of the virtual machine; If it is learned that there is only one numa node in the virtual machine according to the numa node topology information, then directly perform memory hot addition; if it is learned that there are multiple numa nodes in the virtual machine according to the numa node topology information, then obtain the minimum memory numa nodes, and hot add memory to the numa node with the smallest memory. 4. The method for realizing hot addition of virtual machine memory according to claim 3, wherein the memory information stored in the database and the current memory information of the virtual machine are updated by modifying the source code of the virtual machine manager include: The virtual machine is managed by calling a kernel-based kvm virtualization interface; By modifying the source code of the virtualization tool libvirt, the memory information in the Extensible Markup Language XML is updated. 5. The method for realizing hot addition of virtual machine memory according to claim 4, wherein said performing hot addition of virtual machine memory comprises: The Libvirt sends the memory hot-add event to qemu through the socket; The qemu performs memory hot-add according to the memory hot-add event; After performing the memory hot-add, it also includes: If the execution of the memory hot addition fails, a processing result is returned through libvirt; if the execution of the memory hot addition is successful, the memory information in the XML of the virtual machine is updated. 6. A device for realizing hot addition of virtual machine memory, comprising: The management module is used to perform virtual machine memory hot addition according to the memory size of each node in the virtual machine; after the virtual machine memory hot addition is successful, the memory information stored in the database and the memory information stored in the database are modified by modifying the source code of the virtual machine manager. The current memory information of the virtual machine is updated to keep the memory information stored in the database consistent with the current memory information of the virtual machine. 7. The device for realizing hot addition of virtual machine memory according to claim 6, wherein the device further comprises: The virtual machine is created using the open source emulator qemu; The virtual machine manager is a virtualization tool libvirt. 8. The device for realizing hot addition of virtual machine memory according to claim 7, wherein the device further comprises: An acquisition module, configured to acquire the non-uniform memory access numa node topology information of the virtual machine; An execution module, configured to directly perform memory hot-add if it is learned that there is only one numa node in the virtual machine according to the numa node topology information; if it is learned that there are multiple numa nodes in the virtual machine according to the numa node topology information , the numa node with the smallest memory is obtained, and memory hot-add is performed on the numa node with the smallest memory. 9. The device for realizing hot addition of virtual machine memory according to claim 8, wherein the management module is also used for: The virtual machine is managed by calling a kernel-based kvm virtualization interface; By modifying the source code of the virtualization tool libvirt, the memory information in the Extensible Markup Language XML is updated. 10. The device for realizing hot addition of virtual machine memory according to claim 9, wherein the management module is also used for: The Libvirt sends the memory hot-add event to qemu through the socket; The qemu performs memory hot-add according to the memory hot-add event; After performing the memory hot-add, it also includes: If the execution of the memory hot addition fails, a processing result is returned through libvirt; if the execution of the memory hot addition is successful, the memory information in the XML of the virtual machine is updated.