[Qemu-discuss] what is the defferences between /usr/libexec/qemu-kvm and /usr/bin/qemu-system-x86_64?

[yue-kvm]

 what is the defferences between /usr/libexec/qemu-kvm and /usr/bin/qemu-system-x86_64?
> my OS is centos6.2,   qemu-kvm is from a rpm package, while  qemu-system-x86_64 is builded  manually from  source code.
> 1.
> if i can recognize they are the same thing?
> 2. for centos distro, how to build a qemu rpm from source code? it seems there is no  qemu.spec file

thanks