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，

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

    ##  结构体声明
    # @GuestMemInfo
    #
    # Information about Memory usage.
    #
    # @total: total size of Memory
    #
    # @usage: Memory usage
    #
    # Since 2.6
    ##
    { 'struct': 'GuestMemInfo',
      'data': { 'total': 'int', 'usage': 'int' } }
          
    ##  命令声明
    # @guest-get-mem-usage:
    #
    # Get the memory utilization rate.
    #
    # Returns: @GuestMemInfo on success.
    #
    # Since 2.6
    ##
    { 'command': 'guest-get-mem-usage',
      'returns': 'GuestMemInfo' }

    在commands-win32.c中添加命令实现：

GuestMemInfo *qmp_guest_get_mem_usage(Error **errp)
{
      MEMORYSTATUS ms;
      GuestMemInfo *meminfo = g_new0(GuestMemInfo, 1);
      GlobalMemoryStatus(&ms);
      meminfo->usage = (int64_t)ms.dwMemoryLoad;
      meminfo->total = (int64_t)ms.dwTotalPhys;
      return meminfo;
}

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

GuestMemInfo *qmp_guest_get_mem_usage(Error **errp)
{
  error_setg(errp, QERR_UNSUPPORTED);
}

    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