#环境
CentOS8 安装 libvirt
创建虚拟磁盘
创建qcow2镜像，但是其实际占有磁盘大小仅为193K左右，而虚拟机内部显示磁盘大小为10G，也就是磁盘空间使用时才被真正使用，即所谓动态扩张。
qemu-img create -f qcow2 /images/testdrive03.qcow2 10G
-rw-r--r--. 1 root root 193K Oct 12 19:40 vm02.qcow2
创建XML文件
创建XML目录
mkdir -p /xml/
cd /xml/
touch /vm03.xml
👉如果没有XML模板可以复制粘贴，不要自己写，可以从目前的虚机进行导出后再行修改
- 网络上找到的比较详细的XML文件解释
<!-- #提示信息
WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE
OVERWRITTEN AND LOST. Changes to this xml configuration should be made using:
virsh edit win7-02
or other application using the libvirt API.
-->
<domain type='kvm'> #用kvm创建的虚拟机称为domain，type定义使用哪个虚拟机管理程序，值可以是：xen、kvm、qemu、lxc、kqemu
#第二个参数是id，它唯一的标示一个运行的虚拟机，不活跃的客户端没有id。
<name>win7-02</name>
#name参数为虚拟机定义了一个简短的名字，必须唯一
<uuid>6ce14f21-33ac-dc79-5444-f64ccc80ea17</uuid>
#uuid，全球唯一，linux下可以用uuidgen生成
<title>This is my first test kvm</title>
#title参数提供一个对虚拟机简短的说明，它不能包含换行符。
<memory unit='KiB'>2097152</memory>
#可以分配到的最大内存，内存单位由unit定义，单位可以是：K、KiB、M、MiB、G、GiB、T、TiB。默认是KiB。MiB 2048代表2G
<currentMemory unit='KiB'>2097152</currentMemory>
#实际分给给客户端的内存她小于memory的定义，如果没有定义，值和memory一致。
<vcpu placement='static'>1</vcpu>
#vcpu的内容是为虚拟机最多分配几个cpu
<os>
<type arch='x86_64' machine='rhel6.5.0'>hvm</type>
#arch指定虚拟机的CPU构架，machine指定机器的类型。hvm表明该OS被设计为直接运行在裸金属上面，需要全虚拟化。
<boot dev='cdrom'/>
#dev属性的值可以是：fd、hd、cdrom、network，boot的元素可以被设置多个用来建立一个启动优先规则。
</os>
<features> #Hypervisor的特性：
<acpi/> #Hypervisors允许特定的CPU/机器特性打开或关闭，所有的特性都在fearures元素中，以下介绍一些在全虚拟化中常用的标记：
<apic/> #acpi：用于电源管理
<pae/> #pae：扩展物理地址模式，使32位的客户端支持大于4GB的内存
</features>
<cpu mode='host-passthrough'>
<topology sockets='1' cores='4' threads='1'/>
</cpu>
<on_poweroff>destroy</on_poweroff>
#当客户端请求poweroff时执行特定的动作
<on_reboot>restart</on_reboot>
#当客户端请求reboot时执行特定的动作
<on_crash>restart</on_crash>
#当客户端崩溃时执行的动作
#每种状态下可以允许指定如下四种行为：
#destory：domain将会被完全终止，domain的所有资源会被释放
#restart：domain会被终止，然后以相同的配置重新启动
#preserver：domain会被终止，它的资源会被保留用来分析
#rename-restart：domain会被终止，然后以一个新名字被重新启动
<clock offset="localtime" />
#客户端的时间初始化来自宿主机的时间，大多数操作系统期望硬件时钟保持UTC格式，UTC也是默认格式，然而Windows机器却期望它是'localtime'
#UTC：当引导时客户端时钟同步到UTC时钟
#localtime：当引导时客户端时钟同步到主机时钟所在的时区
#timezone：The guest clock will be synchronized to the requested timezone using the timezone attribute
<devices> #所有的设备都是一个名为devices元素的子设备
<emulator>/usr/libexec/qemu-kvm</emulator>
#emulator元素指定模拟设备二进制文件的全路径
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2'/>
<source file='/data/vmdisk/win7-02.qcow2'/>
<target dev='vda' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
</disk>
<disk type='file' device='cdrom'>
<driver name='qemu' type='raw'/>
<source file='/iso/win7.iso'/>
<target dev='hda' bus='ide'/>
<readonly/>
<address type='drive' controller='0' bus='0' target='0' unit='0'/>
</disk>
<disk type='file' device='cdrom'>
<driver name='qemu' type='raw'/>
<source file='/iso/virtio-win-0.1-100.iso'/>
<target dev='hdb' bus='ide'/>
<readonly/>
<address type='drive' controller='0' bus='0' target='0' unit='1'/>
</disk>
<disk type='file' device='floppy'>
<driver name='qemu' type='raw'/>
<source file='/iso/virtio-win-0.1.96_amd64.vfg'/>
<target dev='fda' bus='fdc'/>
<readonly/>
<address type='drive' controller='0' bus='0' target='0' unit='0'/>
</disk>
#所有的设备看起来就像一个disk、floppy、cdrom或者一个 paravirtualized driver，他们通过一个disk元素指定。
#type特性包括:file,block,dir,network，device描述disk如何受到客户端OS的，特性包括：floppy、disk、cdrom、lun，默认是disk
#source元素：在disk的type是file时，file属性指定一个合格的全路径文件映像作为客户端的磁盘，在disk的type是block时，dev属性指定一个主机设备的路径作为disk。
#在disk的type是dir时，dir属性指定一个全路径的目录作为disk，在disk的type是network时，protocol属性指定协议用来访问镜像，镜像的值可以是：nbd，rbd，sheepdog
#dev属性表明本地磁盘在客户端上的实际名称，因为实际设备的名称指定并不能保证映射到客户端OS上的设备
#bus属性指定了哪种类型的磁盘被模拟，值主要有：ide、scsi、virtio、xen、usb、sata
#readonly元素：指定客户端不能修改设备。当一个disk含有type=cdrom，readonly则是默认值。
(disk中virtio-win-0.1-100.iso和virtio-win-0.1.96_amd64.vfg是windows需要的驱动文件，linux系列无需定义)
<controller type='usb' index='0'>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
</controller>
<controller type='ide' index='0'>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
</controller>
<controller type='fdc' index='0'/>
<controller type='virtio-serial' index='0'>
<address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
</controller>
<interface type='bridge'> #类型桥接
<source bridge='br0'/> #桥接的设备名字
<model type='virtio'/>
</interface>
#串行端口
<serial type='file'>
<source path='/tmp/console.log'/>
<target port='0'/>
</serial>
<serial type='pty'>
<target port='1'/>
</serial>
<console type='file'>
<source path='/tmp/console.log'/>
<target type='serial' port='0'/>
</console>
<channel type='spicevmc'>
<target type='virtio' name='com.redhat.spice.0'/>
<address type='virtio-serial' controller='0' bus='0' port='1'/>
</channel>
<input type='tablet' bus='usb'/>
<input type='mouse' bus='ps2'/>
#input元素：input元素含有一个强制的属性，type属性的值可以是mouse或tablet
#bus属性指定一个明确的设备类型，值可以是：xen、ps2、usb。
<graphics type='spice' port='6789' autoport='no' listen='0.0.0.0' keymap='en-us'>
<listen type='address' address='0.0.0.0'/> #graphics元素：graphics含有一个强制的属性type，type的值可以是：sdl、vnc、rdp、desktop、spice
<channel name='main' mode='insecure'/> #vnc则启动vnc服务，port属性指定tcp端口，如果是-1，则表示自动分配
<channel name='display' mode='insecure'/> #vnc的端口自动分配的话是从5900向上递增。listen属性提供一个IP地址给服务器监听，可以单独在listen元素中设置
<channel name='inputs' mode='insecure'/> #passwd属性提供一个vnc的密码
<channel name='cursor' mode='insecure'/> #listen元素：listen元素专门针对vnc和spice设置监听端口等
<channel name='playback' mode='insecure'/> #它包含以下属性：type、address、network。type的值可以是address或network。
<channel name='record' mode='insecure'/> #如果设置了type=address，那么address属性设置一个ip地址或者主机名来监听。
<channel name='smartcard' mode='insecure'/>#如果type=network，则network属性设置一个网络名称在libvirt‘s的网络配置文件中。
<channel name='usbredir' mode='insecure'/>
<image compression='auto_glz'/>
<streaming mode='all'/>
<clipboard copypaste='yes'/>
</graphics>
<video>
<model type='qxl' ram='65536' vram='65536' heads='1'>
<acceleration accel3d='yes' accel2d='yes'/>
</model>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
</video>
<memballoon model='virtio'>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
</memballoon>
</devices>
</domain>
#video元素：是描述声音设备的容器，为了向后完全兼容，如果没有设置video但是有graphics在xml配置文件中，这时libvirt会按照客户端类型增加一个默认的video设备
** 使用virsh dumpxml vm01 导出一份XML模板进行修改
<domain type='kvm' id='3'>
<name>vm01</name>
<uuid>14bc5d73-22d9-4148-bbb2-5b8da7934222</uuid>
<metadata>
<libosinfo:libosinfo xmlns:libosinfo="http://libosinfo.org/xmlns/libvirt/domain/1.0">
<libosinfo:os id="http://centos.org/centos/7.0"/>
</libosinfo:libosinfo>
</metadata>
<memory unit='KiB'>1572864</memory>
<currentMemory unit='KiB'>1572864</currentMemory>
<vcpu placement='static'>2</vcpu>
<resource>
<partition>/machine</partition>
</resource>
<os>
<type arch='x86_64' machine='pc-q35-rhel8.6.0'>hvm</type>
<kernel>/var/lib/libvirt/boot/virtinst-0j8ne2uv-vmlinuz</kernel>
<initrd>/var/lib/libvirt/boot/virtinst-p0_m0nsx-initrd.img</initrd>
<cmdline>inst.repo=https://mirrors.mit.edu/centos/7.9.2009/os/x86_64/</cmdline>
<boot dev='hd'/>
</os>
<features>
<acpi/>
<apic/>
</features>
<cpu mode='custom' match='exact' check='full'>
<model fallback='forbid'>Skylake-Client-IBRS</model>
<vendor>Intel</vendor>
<feature policy='require' name='ss'/>
<feature policy='require' name='hypervisor'/>
<feature policy='require' name='tsc_adjust'/>
<feature policy='require' name='clflushopt'/>
<feature policy='require' name='umip'/>
<feature policy='require' name='md-clear'/>
<feature policy='require' name='stibp'/>
<feature policy='require' name='arch-capabilities'/>
<feature policy='require' name='ssbd'/>
<feature policy='require' name='xsaves'/>
<feature policy='require' name='pdpe1gb'/>
<feature policy='require' name='ibpb'/>
<feature policy='require' name='ibrs'/>
<feature policy='require' name='amd-stibp'/>
<feature policy='require' name='amd-ssbd'/>
<feature policy='require' name='rsba'/>
<feature policy='require' name='skip-l1dfl-vmentry'/>
<feature policy='require' name='pschange-mc-no'/>
<feature policy='disable' name='hle'/>
<feature policy='disable' name='erms'/>
<feature policy='disable' name='rtm'/>
<feature policy='disable' name='mpx'/>
</cpu>
<clock offset='utc'>
<timer name='rtc' tickpolicy='catchup'/>
<timer name='pit' tickpolicy='delay'/>
<timer name='hpet' present='no'/>
</clock>
<on_poweroff>destroy</on_poweroff>
<on_reboot>destroy</on_reboot>
<on_crash>destroy</on_crash>
<pm>
<suspend-to-mem enabled='no'/>
<suspend-to-disk enabled='no'/>
</pm>
<devices>
<emulator>/usr/libexec/qemu-kvm</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2'/>
<source file='/images/testdrive02.qcow2' index='1'/>
<backingStore/>
<target dev='vda' bus='virtio'/>
<alias name='virtio-disk0'/>
<address type='pci' domain='0x0000' bus='0x04' slot='0x00' function='0x0'/>
</disk>
<controller type='usb' index='0' model='qemu-xhci' ports='15'>
<alias name='usb'/>
<address type='pci' domain='0x0000' bus='0x02' slot='0x00' function='0x0'/>
</controller>
<controller type='sata' index='0'>
<alias name='ide'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
</controller>
<controller type='pci' index='0' model='pcie-root'>
<alias name='pcie.0'/>
</controller>
<controller type='virtio-serial' index='0'>
<alias name='virtio-serial0'/>
<address type='pci' domain='0x0000' bus='0x03' slot='0x00' function='0x0'/>
</controller>
<controller type='pci' index='1' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='1' port='0x10'/>
<alias name='pci.1'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0' multifunction='on'/>
</controller>
<controller type='pci' index='2' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='2' port='0x11'/>
<alias name='pci.2'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x1'/>
</controller>
<controller type='pci' index='3' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='3' port='0x12'/>
<alias name='pci.3'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x2'/>
</controller>
<controller type='pci' index='4' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='4' port='0x13'/>
<alias name='pci.4'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x3'/>
</controller>
<controller type='pci' index='5' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='5' port='0x14'/>
<alias name='pci.5'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x4'/>
</controller>
<controller type='pci' index='6' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='6' port='0x15'/>
<alias name='pci.6'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x5'/>
</controller>
<controller type='pci' index='7' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='7' port='0x16'/>
<alias name='pci.7'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x6'/>
</controller>
<interface type='bridge'>
<mac address='52:54:00:2a:be:d4'/>
<source bridge='virbr0'/>
<target dev='vnet2'/>
<model type='virtio'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
</interface>
<serial type='pty'>
<source path='/dev/pts/1'/>
<target type='isa-serial' port='0'>
<model name='isa-serial'/>
</target>
<alias name='serial0'/>
</serial>
<console type='pty' tty='/dev/pts/1'>
<source path='/dev/pts/1'/>
<target type='serial' port='0'/>
<alias name='serial0'/>
</console>
<channel type='unix'>
<source mode='bind' path='/var/lib/libvirt/qemu/channel/target/domain-3-vm01/org.qemu.guest_agent.0'/>
<target type='virtio' name='org.qemu.guest_agent.0' state='disconnected'/>
<alias name='channel0'/>
<address type='virtio-serial' controller='0' bus='0' port='1'/>
</channel>
<input type='tablet' bus='usb'>
<alias name='input0'/>
<address type='usb' bus='0' port='1'/>
</input>
<input type='mouse' bus='ps2'>
<alias name='input1'/>
</input>
<input type='keyboard' bus='ps2'>
<alias name='input2'/>
</input>
<graphics type='vnc' port='5912' autoport='no' listen='0.0.0.0'>
<listen type='address' address='0.0.0.0'/>
</graphics>
<audio id='1' type='none'/>
<video>
<model type='vga' vram='16384' heads='1' primary='yes'/>
<alias name='video0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'/>
</video>
<memballoon model='virtio'>
<alias name='balloon0'/>
<address type='pci' domain='0x0000' bus='0x05' slot='0x00' function='0x0'/>
</memballoon>
<rng model='virtio'>
<backend model='random'>/dev/urandom</backend>
<alias name='rng0'/>
<address type='pci' domain='0x0000' bus='0x06' slot='0x00' function='0x0'/>
</rng>
</devices>
<seclabel type='dynamic' model='selinux' relabel='yes'>
<label>system_u:system_r:svirt_t:s0:c38,c293</label>
<imagelabel>system_u:object_r:svirt_image_t:s0:c38,c293</imagelabel>
</seclabel>
<seclabel type='dynamic' model='dac' relabel='yes'>
<label>+107:+107</label>
<imagelabel>+107:+107</imagelabel>
</seclabel>
</domain>
- 测试简化模板（测试成功）
网络模板
<domain type='kvm'>
<name>vm03</name> //虚拟机名称
<memory>1024000</memory> //最大内存
<currentMemory>1024000</currentMemory> //可用内存
<vcpu>2</vcpu> //虚拟cpu个数
<os>
<type arch='x86_64' machine='pc'>hvm</type>
<boot dev='cdrom'/> //光盘启动 dev属性的值可以是：fd、hd、cdrom、network，boot的元素可以被设置
</os>
<features>
<acpi/> #Hypervisors允许特定的CPU/机器特性打开或关闭，所有的特性都在fearure
<apic/> #acpi：用于电源管理
<pae/> #pae：扩展物理地址模式，使32位的客户端支持大于4GB的内存
</features>
<cpu mode='host-passthrough'>
<topology sockets='1' cores='2' threads='1'/>
</cpu>
<clock offset='localtime'/>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>destroy</on_crash>
<devices>
<emulator>/usr/libexec/qemu-kvm</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2'/> //此处关键，要求libvirt版本至少应该在0.9以上才能支持，libvirt版本升级http://blog.csdn.net/gg296231363/article/details/6891460
<source file='/images/testdrive03.qcow2'/>//目的镜像路径
<target dev='hda' bus='ide'/>
</disk>
<disk type='file' device='cdrom'>
<source file='/images/isos/CentOS-7-x86_64-Minimal-2009.iso'/> //光盘镜像路径
<target dev='hdb' bus='ide'/>
</disk>
<interface type='bridge'> //虚拟机网络连接方式
<source bridge='virbr0'/> //网卡需要设置到主机已有网卡
<mac address="00:16:3e:5d:aa:a8"/> //为虚拟机分配mac地址，务必唯一，否则dhcp获得同样ip,引起冲突
</interface>
<input type='mouse' bus='ps2'/>
<graphics type='vnc' port='-1' autoport='yes' listen = '0.0.0.0' keymap='en-us'/>//vnc方式登录，端口号自动分配，自动加1
</devices>
</domain>
vm03引入后导出的模板
<domain type='kvm' id='12'>
<name>vm03</name>
<uuid>c808471d-5064-4cb1-8190-8af136054717</uuid>
<memory unit='KiB'>1024000</memory>
<currentMemory unit='KiB'>1024000</currentMemory>
<vcpu placement='static'>2</vcpu>
<resource>
<partition>/machine</partition>
</resource>
<os>
<type arch='x86_64' machine='pc-i440fx-rhel7.6.0'>hvm</type>
<boot dev='cdrom'/>
</os>
<features>
<acpi/>
<apic/>
<pae/>
</features>
<cpu mode='host-passthrough' check='none' migratable='on'>
<topology sockets='1' dies='1' cores='2' threads='1'/>
</cpu>
<clock offset='localtime'/>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>destroy</on_crash>
<devices>
<emulator>/usr/libexec/qemu-kvm</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2'/>
<source file='/images/testdrive03.qcow2' index='2'/>
<backingStore/>
<target dev='hda' bus='ide'/>
<alias name='ide0-0-0'/>
<address type='drive' controller='0' bus='0' target='0' unit='0'/>
</disk>
<disk type='file' device='cdrom'>
<driver name='qemu' type='raw'/>
<source file='/images/isos/CentOS-7-x86_64-Minimal-2009.iso' index='1'/>
<backingStore/>
<target dev='hdb' bus='ide'/>
<readonly/>
<alias name='ide0-0-1'/>
<address type='drive' controller='0' bus='0' target='0' unit='1'/>
</disk>
<controller type='usb' index='0' model='piix3-uhci'>
<alias name='usb'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
</controller>
<controller type='pci' index='0' model='pci-root'>
<alias name='pci.0'/>
</controller>
<controller type='ide' index='0'>
<alias name='ide'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
</controller>
<interface type='bridge'>
<mac address='00:16:3e:5d:aa:a8'/>
<source bridge='virbr0'/>
<target dev='vnet10'/>
<model type='rtl8139'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>
<input type='mouse' bus='ps2'>
<alias name='input0'/>
</input>
<input type='keyboard' bus='ps2'>
<alias name='input1'/>
</input>
<graphics type='vnc' port='5900' autoport='yes' listen='0.0.0.0' keymap='en-us'>
<listen type='address' address='0.0.0.0'/>
</graphics>
<audio id='1' type='none'/>
<video>
<model type='cirrus' vram='16384' heads='1' primary='yes'/>
<alias name='video0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
</video>
<memballoon model='virtio'>
<alias name='balloon0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
</memballoon>
</devices>
<seclabel type='dynamic' model='selinux' relabel='yes'>
<label>system_u:system_r:svirt_t:s0:c471,c789</label>
<imagelabel>system_u:object_r:svirt_image_t:s0:c471,c789</imagelabel>
</seclabel>
<seclabel type='dynamic' model='dac' relabel='yes'>
<label>+107:+107</label>
<imagelabel>+107:+107</imagelabel>
</seclabel>
</domain>
- 使用vi编辑器编辑vm03.xml
- 修改name字段
- 修改硬盘路径，并在创建VM之前创建硬盘
👉测试发现如果使用virt-install 命令 加入—location网络安装的化，系统会自动添加os元素
** 系统不能自动生成kernel文件，是从网上自动下载的
官方对于—location参数的解释：https://www.mankier.com/1/virt-install#Installation_Options--l,_--location
这叫direct kernel boot 参考文档：https://documentation.suse.com/sles/15-SP1/html/SLES-all/cha-libvirt-config-virsh.html#sec-libvirt-config-directkernel-virsh
XML文件显示如下
<os>
<type arch='x86_64' machine='pc-q35-rhel8.6.0'>hvm</type>
<kernel>/var/lib/libvirt/boot/virtinst-gxheig0s-vmlinuz</kernel>
<initrd>/var/lib/libvirt/boot/virtinst-g8khb3vk-initrd.img</initrd>
<cmdline>inst.repo=https://mirrors.mit.edu/centos/7.9.2009/os/x86_64/</cmdline>
<boot dev='hd'/>
</os>
👉VNC默认端口从5900开始，没有设置端口的化KVM默认向上加1。
***切记要打开防火墙端口，不然忙半天找不到VNC连接不上的问题！！！其实不是VM的问题。
导入XML文件
virsh define vm02.xml
运行虚拟机
virsh start vm02
测试修改xml文件来操作硬件变化
virsh edit vm03.xml