Virtio 是一种 I/O 半虚拟化解决方案，是一套通用 I/O 设备虚拟化的程序，是对半虚拟化 Hypervisor 中的一组通用 I/O 设备的抽象。提供了一套上层应用与各 Hypervisor 虚拟化设备（KVM，Xen，VMware等）之间的通信框架和编程接口，减少跨平台所带来的兼容性问题，大大提高驱动程序开发效率。
网卡：
全虚拟化网卡： 虚拟化层完全模拟出来的网卡；
半虚拟化网卡： 通过驱动对操作系统进行了修改，即Virtio技术。
KVM虚拟机操作：
[root@localhost ~]#
[root@localhost ~]# virt-what
kvm
[root@localhost ~]# ethtool -i eth0 #显示网卡驱动的信息，如驱动的名称、版本等
driver: virtio_net
version: 1.0.0
firmware-version:
bus-info: 0000:00:03.0
supports-statistics: no
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no
#查看配置文件信息
[root@node3 ~]# virsh dumpxml centos7.2 |grep interface -C2
<address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
</controller>
<interface type='network'>
<mac address='52:54:00:5f:d4:8c'/>
<source network='default' bridge='virbr0'/>
--
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>
<serial type='pty'>
<source path='/dev/pts/0'/>
[root@node3 ~]# virsh domblklist centos7.2 #查看存储硬盘
Target Source
------------------------------------------------
vda /var/lib/libvirt/images/centos7.2.qcow2
hda -
[root@node3 ~]# virsh net-list #查看网络列表
Name State Autostart Persistent
----------------------------------------------------------
default active yes ye
[root@node3 ~]# virsh net-info default
Name: default
UUID: 8e7a52c9-2051-4cad-bc50-93c13008ec0e
Active: yes
Persistent: yes
Autostart: yes
Bridge: virbr0
[root@node3 ~]# virsh net-edit default #编辑default网卡
[root@node3 ~]# sysctl -a | grep ip_for #查看配置路由转发
net.ipv4.ip_forward = 1
net.ipv4.ip_forward_use_pmtu = 0
获取虚拟机网卡信息：virsh domiflist 虚拟机名
[root@node3 ~]# brctl show
bridge name bridge id STP enabled interfaces
virbr0 8000.fe54005fd48c yes vnet0
vnet3
virbr1 8000.fe54008b1fcc yes vnet1
vnet2
[root@node3 ~]# virsh domiflist centos7.2
Interface Type Source Model MAC
-------------------------------------------------------
vnet0 network default virtio 52:54:00:5f:d4:8c
vnet1 network allen virtio 52:54:00:8b:1f:cc
vnet2 network allen virtio 52:54:00:96:7b:91
vnet3 network default virtio 52:54:00:f2:2f:c7
#永久添加网卡命令
[root@node3 ~]# virsh attach-interface centos7.2 --type network --source allen --model virtio --config --live
Interface attached successfully
#永久删除网卡命令
[root@node3 ~]# virsh detach-interface centos7.2 --type network --mac 52:54:00:96:7b:91
Interface detached successfully
[root@node3 ~]# virsh domiflist centos7.2 #查看虚拟机网络
Interface Type Source Model MAC
-------------------------------------------------------
vnet0 network default virtio 52:54:00:5f:d4:8c
vnet1 network allen virtio 52:54:00:8b:1f:cc
vnet3 network default virtio 52:54:00:f2:2f:c7
[root@node3 ~]# virsh domif-getlink centos7.2 vnet3 #获取网口
vnet3 up
[root@node3 ~]# virsh domif-setlink centos7.2 vnet3 down #关闭或打开某个网口
Device updated successfully
[root@node3 ~]# virsh domif-getlink centos7.2 vnet3
vnet3 down
[root@node3 ~]# virsh domif-getlink centos7.2 vnet3
vnet3 down
[root@node3 ~]# virsh domif-setlink centos7.2 vnet3 up
Device updated successfully
[root@node3 ~]# virsh domif-getlink centos7.2 vnet3
vnet3 up
#生产虚拟机配置文件
[root@node3 ~]#virsh dumpxml centos7.2 > /etc/libvirt/qemu/centos7.3.xml
#通过配置文件定义一个虚拟机
[root@node3 ~]# virsh define /etc/libvirt/qemu/centos7.3.xml
为接口绑定地址
临时
[root@node3 ~]# ip addr add dev eth0 172.16.30.240/24
[root@node3 ~]# ip addr add dev eth0 172.16.30.241/24
[root@node3 ~]# ip a s eth0
[root@node3 ~]# vim /etc/sysconfig/network-scripts/ifcfg-enp3s0
IPADDR=172.16.30.30
PREFIX=24
IPADDR1=172.16.30.240
PREFIX1=24
IPADDR2=172.16.30.241
PREFIX2=24
GATEWAY=172.16.30.254
[root@node3 ~]# nmcli connection show #查看当前连接状态
[root@node3 ~]# nmcli connection reload #重启服务
[root@node3 ~]# nmcli connection up enp3s0 #启用enp3s0 连接配置
[root@node1 ~]# virsh nodedev-list --tree
computer
|
+- net_lo_00_00_00_00_00_00
+- net_virbr0_nic_52_54_00_35_6a_2b
+- pci_0000_00_00_0
+- pci_0000_00_01_0
+- pci_0000_00_07_0
+- pci_0000_00_07_1
| |
| +- scsi_host1
| +- scsi_host2
| |
| +- scsi_target2_0_0
| |
| +- scsi_2_0_0_0
| |
| +- block_sr0_VMware_Virtual_IDE_CDROM_Drive_10000000000000000001
| +- scsi_generic_sg1
|
+- pci_0000_00_07_3
+- pci_0000_00_07_7
+- pci_0000_00_0f_0
| |
| +- drm_card0
| +- drm_renderD128
|
+- pci_0000_00_10_0
| |
| +- scsi_host0
| |
| +- scsi_target0_0_0
| |
| +- scsi_0_0_0_0
| |
| +- block_sda
| +- scsi_generic_sg0
|
+- pci_0000_00_11_0
| |
| +- pci_0000_02_00_0
| | |
| | +- usb_usb2
| | |
| | +- usb_2_0_1_0
| | +- usb_2_1
| | | |
| | | +- usb_2_1_1_0
| | |
| | +- usb_2_2
| | |
| | +- usb_2_2_1_0
| |
| +- pci_0000_02_01_0
| | |
| | +- net_eno16777736_00_0c_29_7c_7a_33
| |
| +- pci_0000_02_02_0
| +- pci_0000_02_03_0
| | |
| | +- usb_usb1
| | |
| | +- usb_1_0_1_0
| |
| +- pci_0000_02_05_0
| |
| +- net_eno33554984_00_0c_29_7c_7a_3d
|
+- pci_0000_00_15_0
+- pci_0000_00_15_1
[root@node1 ~]# virsh nodedev-dumxml net_lo_00_00_00_00_00_00
error: unknown command: 'nodedev-dumxml'
[root@node1 ~]# virsh nodedev-dumpxml net_lo_00_00_00_00_00_00
<device>
<name>net_lo_00_00_00_00_00_00</name>
<path>/sys/devices/virtual/net/lo</path>
<parent>computer</parent>
<capability type='net'>
<interface>lo</interface>
<address>00:00:00:00:00:00</address>
<link state='unknown'/>
<feature name='rx'/>
<feature name='tx'/>
<feature name='sg'/>
<feature name='tso'/>
<feature name='gso'/>
<feature name='gro'/>
<capability type='80203'/>
</capability>
</device>
补充命令：
[root@node1 ~]# openssl rand -hex 6 |sed -r 's/(..)/\1:/g; s/.$//'
0a:d8:af:09:13:1d
[root@node1 ~]# uuidgen
86562401-120a-4fa4-ae5e-e31c2b78b31e