1.qemu update
KVM
1.git clone git://vt-sync/qemu.git ## clone qemu repo
2.cd qemu.git
you can check which branch of qemu
git branch
you can checkout to uq/master tree
git checkout uq/master
3.then compile the qemu
./configure --target-list=x86_64-softmmu
./configure --target-list=x86_64-softmmu --enable-kvm --enable-numa --enable-vnc --disable-gtk --disable-sdl # -display sdl(在这一步可以加上qemu的一些function比如--enable-numa[支持numa])
4.make -j 32(加j 10表示10个进程同时work)
5.make install
XEN
./configure --enable-xen --target-list=i386-softmmu [for xen qemu的编译]
2.qemu创建img
1.qemu-img create -b 所依据的img名 -f qcow2 自己所要的img名
example：
qemu-img create -b /share/xvs/img/linux/ia32e_rhel7u2_kvm.img -f qcow2 ./rhel7u2_kvm_lmce.qcow2
2.做img步骤：
a.dd if=/dev/zero of=ia32e_rhel7u4_snapshort3_kvm.img bs=1M count=30000
或者 qemu-img create -f raw /home/window8_2.img 60G
b.qemu-system-x86_64 -enable-kvm -cpu host -m 4028 -smp 4 -boot order=cd -hda /root/junliang/ia32e_rhel7u4_snapshort3_kvm.img -cdrom /root/junliang/RHEL-7.4-20170608.3-Server-x86_64-dvd1.iso