KVM--QEMU Guest Agent（十七）

qemu guest agent概述

QEMU Guest Agent是一种在虚拟机内部运行的守护进程（qemu-guest-agent.service），旨在协助Hypervisor管理虚拟机。QEMU通过在宿主机和虚拟机之间建立一个数据通道（channel），这个通道的两端分别是虚拟机内的串口和宿主机上的unix socket文件。这种设置允许宿主机通过qga扩展对虚拟机的控制能力，例如获取虚拟机的IP地址等。

libvirt提供了专门的virDomainQemuAgentCommand API（对应virsh qemu-agent-command命令）来与qemu-guest-agent通信。此外，libvirt还内置了支持qga的API，例如reboot、shutdown等。

1. 编辑虚拟机

virsh edit vm01

2. 在宿主机上的虚拟机XML中添加channel

<channel type="unix"><target name="org.qemu.guest_agent.0" type="virtio"></target></channel>

3. 启动虚拟机

virsh start vm01

4. 在Linux虚拟机中安装qemu-guest-agent

yum install qemu-guest-agent
setenforce 0
systemctl restart qemu-guest-agent.service

5. 在宿主机上进行测试

virsh qemu-agent-command vm01 '{"execute":"guest-info"}'
virsh qemu-agent-command vm01 '{"execute":"guest-network-get-interfaces"}'
virsh qemu-agent-command vm01 '{"execute":"guest-ping"}'
virsh reboot --mode agent vm01
virsh shutdown --mode agent vm01

Windows virtio-win iso下载地址：

https://www.php.cn/link/55ae2484d29529c6925ac39b67603516

Windows qemu-ga安装包下载地址：

https://www.php.cn/link/a56aaa84688618331d4b0e77756d6c0f

qemu-guest-agent修改虚拟机用户密码

1. guest-set-user-password

（1）在Windows虚拟机中安装qemu-ga-x86_64.msi程序

（2）qemu-agent-command命令中密码必须是base64编码格式

[root@kvm-node1 ~]# python
Python 2.7.5 (default, Oct 14 2020, 14:45:30) [GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import base64
>>> print base64.b64encode('password')
cGFzc3dvcmQ=

（3）关闭虚拟机

virsh destroy win10

（4）修改win10的XML文件，添加如下配置

<channel type="unix"><target name="org.qemu.guest_agent.0" type="virtio"></target></channel>

（5）启动虚拟机

virsh start win10

（6）使用qemu-agent-command命令guest-set-user-password修改密码

virsh qemu-agent-command win10 '{"execute":"guest-set-user-password","arguments":{"username":"admin","password":"cGFzc3dvcmQ=","crypted":false}}'
{"return":{}}

2. virsh set-user-password

使用virsh set-user-password命令修改密码

virsh set-user-password --domain 6 --user root --password password
Password set successfully for root in 6

QEMU Guest Agent支持的指令

guest-exec guest-exec-status guest-file-close guest-file-flush guest-file-open guest-file-read guest-file-seek guest-file-write guest-fsfreeze-freeze guest-fsfreeze-freeze-list guest-fsfreeze-status guest-fsfreeze-thaw guest-fstrim guest-get-fsinfo guest-get-host-name guest-get-memory-block-info guest-get-memory-blocks guest-get-osinfo guest-get-time guest-get-timezone guest-get-users guest-get-vcpus guest-info guest-network-get-interfaces guest-ping guest-set-memory-blocks guest-set-time guest-set-user-password guest-set-vcpus guest-shutdown guest-suspend-disk guest-suspend-hybrid guest-suspend-ram guest-sync guest-sync-delimited