run either of the two lines:
egrep '(vmx|svm)' /proc/cpuinfo
kvm-ok
http://www.linux-kvm.org/page/Networking
Public bridge
Public bridge allow guest directly communicate with outside using host's network card.
Below configuration works for me.
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto br0
iface br0 inet static
address 192.168.10.13
netmask 255.255.255.0
network 192.168.10.0
broadcast 192.168.10.255
gateway 192.168.10.1
dns-nameservers 8.8.8.8 8.8.4.4
dns-search eastip.com
bridge_ports eth0
bridge_fd 0
bridge_hello 2
bridge_maxage 12
bridge_stp off