How do I run QEMU with a 64-bit processor on a 64-bit machine?

I'm running Ubuntu 11.04 (Natty Narwhal) 64-bit and recently installed qemu-kvm. Now I want to start a 64-bit live CD using:

qemu -m 512 -boot d -cdrom archlinux-2010.05-netinstall-x86_64.iso

This loads the image, and I can select to boot Arch Linux the normal way, but it will give me an error that I have to use a 64-bit machine to run this live CD. Now, I tried to get a list of CPUs QEMU can emulate for me, and ended up with this output:

axle@z370l:~/Downloads$ qemu -cpu ?
x86           [n270]
x86         [athlon]
x86       [pentium3]
x86       [pentium2]
x86        [pentium]
x86            [486]
x86        [coreduo]
x86          [kvm32]
x86         [qemu32]
x86          [kvm64]
x86       [core2duo]
x86         [phenom]
x86         [qemu64]
x86           [host]

So, how do I make QEMU emulate a 64-bit CPU?

I asked myself the same question a few days ago and couldn't figure it out. Now I see your list (perhaps I couldn't find how to get this list?) and the obvious choices seem to be kvm64, qemu64 and host. I also tried core2duo and phenom, they also work.

I asked myself the same question a few days ago and couldn't figure it out. Now I see your >list (perhaps I couldn't find how to get this list?) and the obvious choices seem to be >kvm64, qemu64 and host. I also tried core2duo and phenom, they also work.

Running "qemu -cpu qemu64 ..." (or other architectures) did not work for me (on Debian Sid/unstable). I did get my 64bit ISO image to run with "qemu-system-x86_64 ..."