libvirt_kvm技巧收集

生成MAC地址
设置udev权限
配置VDE网络接口

生成MAC地址

随机生成MAC:python

#!/usr/bin/python 
# generates a MAC address for Xen domU
# http://www.vpsee.com

import random
import uuid

mac = [ 0x00, 0x16, 0x3e, random.randint(0x00, 0x7f),
random.randint(0x00, 0xff), random.randint(0x00, 0xff) ]
s = []
for item in mac:
        s.append(str("%02x" % item))
print ':'.join(s)

随机生成MAC2:python

#!/usr/bin/python 
# gen by LocalMAC
def get_local_mac():
   return uuid.uuid1().hex[-12:]

def make_mac(local_mac):
    import random
    #random.randint(0x00, 0x7f)  
    mac = [random.randint(0x00, 0xff), random.randint(0x00, 0xff) ]
    s = [local_mac[0:2], local_mac[2:4],local_mac[4:6],local_mac[6:8]]
    for item in mac:
      s.append(str("%02x" % item))
    return ( ':'.join(s) )

mac=get_local_mac()
print("LocalMAC:%s" % mac)
print(make_mac(mac))

随机生成MAC地址-shell

printf -v macaddr "52:54:%02x:%02x:%02x:%02x" $(( $RANDOM & 0xff)) $(( $RANDOM & 0xff )) $(( $RANDOM & 0xff)) $(( $RANDOM & 0xff ))
echo $macaddr

设置udev权限

用户组

sudo adduser $(id -un) kvm
sudo adduser $(id -un) vde2-net
sudo adduser $(id -un) tun
sudo adduser $(id -un) libvirtd

设置usb设备权限

# 给 plugdev 组（不推荐 kvm 组）赋予 USB 设备操作权
vi /etc/udev/rules.d/10-usb-plugdev.rules #{
SUBSYSTEM=="usb_device", GROUP="plugdev", MODE="0664"
SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", GROUP="plugdev", MODE="0664"
#}

vi /etc/udev/rules.d/10-vboxdrv.rules #{
KERNEL=="vboxdrv", NAME="vboxdrv", OWNER="root", GROUP="root", MODE="0600"
KERNEL=="vboxnetctl", NAME="vboxnetctl", OWNER="root", GROUP="root", MODE="0600"
SUBSYSTEM=="usb_device", ACTION=="add", RUN+="/usr/share/virtualbox/VBoxCreateUSBNode.sh $major $minor $attr{bDeviceClass}"
SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", RUN+="/usr/share/virtualbox/VBoxCreateUSBNode.sh $major $minor $attr{bDeviceClass}"
SUBSYSTEM=="usb_device", ACTION=="remove", RUN+="/usr/share/virtualbox/VBoxCreateUSBNode.sh --remove $major $minor"
SUBSYSTEM=="usb", ACTION=="remove", ENV{DEVTYPE}=="usb_device", RUN+="/usr/share/virtualbox/VBoxCreateUSBNode.sh --remove $major $minor"
#}
 
# 加入组
gpasswd -a $(id -un) kvm
gpasswd -a $(id -un) vboxusers
# 若尚未入 plugdev 组，则再
gpasswd -a $(id -un) plugdev

设置tun访问权限

Give New Devices tun Group Ownership:

This is a udev rule that is fired when a new tun/tap device is created:

cat <<EOF | sudo tee /etc/udev/rules.d/41-permissions-tun.rules
# provide non-root user access to tun/tap devices for Virtual Machines using VDE etc
KERNEL=="tun", GROUP="tun"
EOF

Because the user is a member of the 'tun' group they can read and write to tun/tap devices. This makes it possible for VM guests to run with regular user permissions and still use VDE networking.

To reread the udev rules do:

sudo udevadm control --reload_rules

配置VDE网络接口

Define the VDE Network Interface:

原文: http://tjworld.net/wiki/Linux/Ubuntu/VirtualMachinesWithVDENetworking

/etc/network/interfaces

#need install vde2 dnsmasq

cat <<EOF | sudo tee -a /etc/network/interfaces
# KVM/QEMU Virtual Machine Network
auto kvm0
iface kvm0 inet static
    address 10.254.1.254
    netmask 255.255.255.0
    pre-up /usr/bin/vde_switch --tap ${IFACE} --daemon --group vde2-net --sock /var/run/${IFACE}.ctl \
     --mod 775 --mgmtmode 770 --mgmt /var/run/${IFACE}-manage --pidfile /var/run/${IFACE}_vde.pid
    up /usr/sbin/dnsmasq --interface=${IFACE}  --except-interface=lo --bind-interfaces --user=nobody \
     --dhcp-range=kvm,10.254.1.1,10.254.1.253,255.255.255.0,10.254.1.255,8h \
     --domain=lan.tjworld.net --pid-file=/var/run/${IFACE}_dnsmasq.pid --conf-file
    up echo "`route -n | sed -n 's/^0\.0\.0\.0 .* \(.*\)$/\1/p'`" > /var/run/${IFACE}_route
    up iptables -t nat -A POSTROUTING -o `cat /var/run/${IFACE}_route` -j MASQUERADE
    down iptables -t nat -D POSTROUTING -o `cat /var/run/${IFACE}_route` -j MASQUERADE
    down kill -s TERM `cat /var/run/${IFACE}_dnsmasq.pid` && rm -f /var/run/${IFACE}_dnsmasq.pid
    post-down kill -s HUP `cat /var/run/${IFACE}_vde.pid`
    post-down rm -f /var/run/${IFACE}_route 
EOF

# start the interface
sudo ifup kvm0

# stop the interface
sudo ifdown kvm0

And the netfilters rule:

sudo iptables -t nat -nvL POSTROUTING
Chain POSTROUTING (policy ACCEPT 2233 packets, 205K bytes)
 pkts bytes target     prot opt in     out     source               destination         
    3   193 MASQUERADE  all  --  *      eth0    0.0.0.0/0            0.0.0.0/0

KVM Start-up Scripts

Every VM configuration is going to be slightly different so I'm not going to dwell on the individual options. I'll focus on the options that are important to networking with VDE.

I'll start with an example start-up script for Ubuntu Gutsy Server using my enhanced kvm-72:

#!/bin/bash
qemuctl -qemu kvm -name Gutsy-Server -boot d -m 450 -hda /home/all/VirtualMachines/Ubuntu-Gutsy-Server-x86.qcow2 -k en-gb \
 -net nic,model=rtl8139,macaddr=56:44:45:30:30:32,vlan=0 -net vde,sock=/var/run/kvm0.ctl,vlan=0 $@

You'll notice it is using qemuctl to provide basic GUI control. That can be removed easily (just delete "qemuctl -qemu").

The same script for the pre-kvm-72 hypervisor simply wraps the kvm start-up in a call to vdeq. Here it is:

#!/bin/bash
qemuctl -qemu vdeq kvm -name Gutsy-Server -boot d -m 450 -hda /home/all/VirtualMachines/Ubuntu-Gutsy-Server-x86.qcow2 -k en-gb \
 -net nic,model=rtl8139,macaddr=56:44:45:30:30:32,vlan=0 -net vde,sock=/var/run/kvm0.ctl,vlan=0 $@

You can see the only difference is that qemuctl is told that the qemu binary is called "vdeq" not "kvm". Without qemuctl the start-up would be:

#!/bin/bash
vdeq kvm -name Gutsy-Server -boot d -m 450 -hda /home/all/VirtualMachines/Ubuntu-Gutsy-Server-x86.qcow2 -k en-gb \
 -net nic,model=rtl8139,macaddr=56:44:45:30:30:32,vlan=0 -net vde,sock=/var/run/kvm0.ctl,vlan=0 $@