Hi,
    The final effect is as follows:
    
[malei@xentest-4-1 Fri Dec 28 ~/honeypot/xen/xen-4.1.2]$ qemu-img-xen cat -f /1/boot.ini ~/vm-check.img 
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect

[malei@xentest-4-1 Fri Dec 28 ~/honeypot/xen/xen-4.1.2]$ qemu-img-xen ls -l -d /1/ ~/vm-check.img 
【name                 size(bytes) dir?      date                create-time】
AUTOEXEC.BAT 0                file 2010-12-22        17:30:37
boot.ini               211                file 2010-12-23        01:24:41
bootfont.bin  322730                file 2004-11-23        20:00:00



As you see above, the patch add two sub-commands for qemu-img-xen:cat and ls.

For details in the patch, please check the attachment.