qemu-ga windows下的安装及监控开发

windows安装qemu-ga

虚拟机配置里添加virtio serial端口

#virsh edit instance-name

devices里添加下面这段配置，

1 <channel type='unix'>
2     <source mode='bind' path='/var/lib/libvirt/qemu/org.qemu.guest_agent.0.instance-name.sock'/>
3     <target type='virtio' name='org.qemu.guest_agent.0'/>
4     <address type='virtio-serial' controller='0' bus='0' port='1'/>
5 </channel>

安装Qemu Guest Agent服务

#wget https://fedorapeople.org/groups/virt/virtio-win/virtio-win.repo -O /etc/yum.repos.d/virtio-win.repo

#yum install virtio-win

安装virtio-win包，virtio-win里包含windows virtio设备驱动，及qemu-ga的安装包。

将msi安装文件和virtio-win.iso拷贝到windows下。

virtio-win.iso包含各个windows版本下的virtio serial驱动，安装对应版本的驱动。

安装对应版本qemu-ga.msi，至此，qga安装完毕。

qga功能扩展

搭建编译环境：

rpm -ivh epel-release
下载 Microsoft VSS SDK: http://www.microsoft.com/en-us/download/details.aspx?id=23490
提取Microsoft VSS SDK的源文件（qemu/scripts下提供了extract-vsssdk-headers，也可以在windows下解压后拷贝到linux上）
wget http://wiki.qemu-project.org/download/qemu-2.6.0-rc1.tar.bz2
yum install -y mingw64-pixman
yum install -y mingw64-glib2
yum install -y mingw64-gmp
yum install -y mingw64-SDL
yum install -y mingw64-pkg-config
./configure --enable-guest-agent --with-vss-sdk=/vss_path --cross-prefix=x86_64-w64-mingw32-
make qemu-ga.exe

添加功能示例（添加内存使用率检测）

编辑qapi-schema.json，添加自定义结构体及命令声明。

 1     ##  结构体声明
 2     # @GuestMemInfo
 3     #
 4     # Information about Memory usage.
 5     #
 6     # @total: total size of Memory
 7     #
 8     # @usage: Memory usage
 9     #
10     # Since 2.6
11     ##
12     { 'struct': 'GuestMemInfo',
13       'data': { 'total': 'int', 'usage': 'int' } }
14           
15     ##  命令声明
16     # @guest-get-mem-usage:
17     #
18     # Get the memory utilization rate.
19     #
20     # Returns: @GuestMemInfo on success.
21     #
22     # Since 2.6
23     ##
24     { 'command': 'guest-get-mem-usage',
25       'returns': 'GuestMemInfo' }

在commands-win32.c中添加命令实现：

1 GuestMemInfo *qmp_guest_get_mem_usage(Error **errp)
2 {
3       MEMORYSTATUS ms;
4       GuestMemInfo *meminfo = g_new0(GuestMemInfo, 1);
5       GlobalMemoryStatus(&ms);
6       meminfo->usage = (int64_t)ms.dwMemoryLoad;
7       meminfo->total = (int64_t)ms.dwTotalPhys;
8       return meminfo;
9 }

　在commands-posix.c中添加命令实现(直接返回QERR_UNSUPPORTED错误)：

1 GuestMemInfo *qmp_guest_get_mem_usage(Error **errp)
2 {
3   error_setg(errp, QERR_UNSUPPORTED);
4 }

重新编译qemu-ga.exe，替换C:Program Filesqemu-ga下的qemu-ga.exe，重启服务即可。

(dll依赖，在/usr/x86_64-w64-mingw32/sys-root/mingw/bin/下可找到。)

参考文献：

http://wiki.qemu.org/Features/QAPI/GuestAgent

http://wiki.libvirt.org/page/Qemu_guest_agent

http://fedoraproject.org/wiki/Windows_Virtio_Drivers

http://lists.gnu.org/archive/html/qemu-discuss/2014-11/msg00027.html