OpenStack桌面虚拟化支持USB重定向和声卡
公司测试OpenStack的桌面虚拟化，默认情况下生成的libvirt的xml是不支持USB重定向和声卡，最快捷的方法就是，Hack下源码，硬加进去：
vim /usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py
def to_xml(self, context, instance, network_info, disk_info,
image_meta=None, rescue=None,
block_device_info=None, write_to_disk=False):
# We should get image metadata every time for generating xml
if image_meta is None:
(image_service, image_id) = glance.get_remote_image_service(
context, instance['image_ref'])
image_meta = compute_utils.get_image_metadata(
context, image_service, image_id, instance)
# NOTE(danms): Stringifying a NetworkInfo will take a lock. Do
# this ahead of time so that we don't acquire it while also
# holding the logging lock.
network_info_str = str(network_info)
LOG.debug(_('Start to_xml '
'network_info=%(network_info)s '
'disk_info=%(disk_info)s '
'image_meta=%(image_meta)s rescue=%(rescue)s'
'block_device_info=%(block_device_info)s'),
{'network_info': network_info_str, 'disk_info': disk_info,
'image_meta': image_meta, 'rescue': rescue,
'block_device_info': block_device_info},
instance=instance)
conf = self.get_guest_config(instance, network_info, image_meta,
disk_info, rescue, block_device_info)
pre_xml = conf.to_xml()
hack_xml = """
"""
tar_obj = ''
libvit_obj = minidom.parseString(pre_xml)
hack_obj = minidom.parseString(hack_xml)
for c_lib_obj in libvit_obj.childNodes[0].childNodes:
if (isinstance(c_lib_obj, minidom.Element) and c_lib_obj.tagName == 'devices'):
c_lib_obj.childNodes.extend(hack_obj.childNodes[0].childNodes)
xml = libvit_obj.toxml()
if write_to_disk:
instance_dir = libvirt_utils.get_instance_path(instance)
xml_path = os.path.join(instance_dir, 'libvirt.xml')
libvirt_utils.write_to_file(xml_path, xml)
LOG.debug(_('End to_xml xml=%(xml)s'),
{'xml': xml}, instance=instance)
return xml
简单的说，就是让Nova生成libvirt xml的时候，硬编码进去相关的xml标签，好暴力，但是高效好用！ 8 个评论
班长好，我搭建的OpenStack环境也需要USB重定向，但是安装你的方法把代码加进去后，并没有在生成的实例xml文件中增加关于USB的标签信息，还是原来的那些内容？ 我是关闭实例后重启，xml是重新生成了，但内容没变，不知是我那里配置的问题吗？ 另外我的python是2.7（/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py）
以下是我加的代码：
----------------------------------------------------------------------
def _get_guest_xml(self, context, instance, network_info, disk_info,
image_meta, rescue=None,
block_device_info=None, write_to_disk=False):
# NOTE(danms): Stringifying a NetworkInfo will take a lock. Do
# this ahead of time so that we don't acquire it while also
# holding the logging lock.
network_info_str = str(network_info)
msg = ('Start _get_guest_xml '
'network_info=%(network_info)s '
'disk_info=%(disk_info)s '
'image_meta=%(image_meta)s rescue=%(rescue)s '
'block_device_info=%(block_device_info)s' %
{'network_info': network_info_str, 'disk_info': disk_info,
'image_meta': image_meta, 'rescue': rescue,
'block_device_info': block_device_info})
# NOTE(mriedem): block_device_info can contain auth_password so we
# need to sanitize the password in the message.
LOG.debug(strutils.mask_password(msg), instance=instance)
conf = self._get_guest_config(instance, network_info, image_meta,
disk_info, rescue, block_device_info,
context)
pre_xml = conf.to_xml()
hack_xml = """
<append>
<controller type='usb' index='0' model='ich9-ehci1'/>
<controller type='usb' index='0' model='ich9-uhci1'>
<master startport='0'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci2'>
<master startport='2'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci3'>
<master startport='4'/>
</controller>
<redirdev bus='usb' type='spicevmc'/>
<redirdev bus='usb' type='spicevmc'/>
<redirdev bus='usb' type='spicevmc'/>
<redirdev bus='usb' type='spicevmc'/>
<sound model='ich6'>
<alias name='sound0'/>
</sound>
</append>
"""
tar_obj = ''
libvit_obj = minidom.parseString(pre_xml)
hack_obj = minidom.parseString(hack_xml)
for c_lib_obj in libvit_obj.childNodes[0].childNodes:
if (isinstance(c_lib_obj, minidom.Element) and c_lib_obj.tagName == 'devices'):
c_lib_obj.childNodes.extend(hack_obj.childNodes[0].childNodes)
xml = libvit_obj.toxml()
if write_to_disk:
instance_dir = libvirt_utils.get_instance_path(instance)
xml_path = os.path.join(instance_dir, 'libvirt.xml')
libvirt_utils.write_to_file(xml_path, xml)
LOG.debug('End _get_guest_xml xml=%(xml)s',
{'xml': xml}, instance=instance)
return xml
-----------------------------------------------------------------------------------
把/usr/lib/python2.7/site-packages/nova/virt/libvirt/文件夹下的driver.pyc和driver.pyo文件删除或改个名，你修改的driver.py就可以生效了
班长好，请教个问题，在我的平台下没有/usr/lib/python2.6/site-packages这个目录，我找到一个/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py文件，然后把你的code，贴到def _get_guest_xml里，然后关闭和重启实例后，发现use redirection还是没有打开，感觉实例启动的时候没有执行我修改的driver.py，请问这是为啥，我修改的文件不对吗？多谢回答。
