I really appreciate your quick answer. Today, I tried an older kernel, linux-image-2.6.32-5-amd64.deb. Yes, it works very well with qemu-kvm 0.14.1.
So I changed the environment as follows: -. linux-image 3.1rc7 (in experimental) + qemu-kvm 0.14.1 --> failed -. linux-image 3.0 + qemu-kvm 0.15.1+dfsg-1 --> failed (segmentation fault) Anyway, I will try to post in kvm@vger mailing-list. Thank you so much. Regards, Hae-woo Park.