用kvm-img创建一个10G大小的镜像文件： 
kvm-img create -f qcow2 win2008.img 10G 

因为windows没有默认的virtio驱动，所以先下载 
wget http://alt.fedoraproject.org/pub/alt/virtio-win/latest/p_w_picpaths/bin/virtio-win-0.1-15.iso 
wget http://alt.fedoraproject.org/pub/alt/virtio-win/latest/p_w_picpaths/bin/virtio-win-1.1.16.vfd 

启动kvm，映射驱动vfd到软盘A 
kvm -m 1024 -cdrom en_windows_server_2008_r2_dvd.iso -drive file=win2008.img,if=virtio,boot=on -fda virtio-win-1.1.16.vfd -boot d -nographic -vnc :1 
用vnc访问安装，在安装的时候需要选择一下硬盘驱动，安装好以后，停掉虚拟机，重新用以下命令启动 
kvm -m 1024 -drive file=win2008.img,if=virtio,boot=on -cdrom virtio-win-0.1-15.iso -net nic,model=virtio -net user -boot c -nographic -vnc :1 
再用vnc访问，应该会提示自动安装好了virtio的网卡驱动 

用glance添加这个镜像，指定格式为qcow2 
glance add -A your_glance_token name="win2008" is_public=true disk_format=qcow2 < win2008.img 

这样就完成了