I have a small problem with the blktap, that when I use "tap:aio" protocol to access my disk, the domU stop booting with following message:

[ 0.185031] PCI: Fatal: No config space access function found
[ 0.189998] Unable to read sysrq code in control/sysrq
[ 0.350220] i8042: No controller found
[ 0.452153] /home/abuild/rpmbuild/BUILD/kernel-xen-3.1.0/linux-3.1/drivers/rtc/hctosys.c: unable to open rtc device (rtc0)

but when i switched to then "file" protocol the domU boot process would succeed. Anyone knows how to solve this problem?

Additional info:

I'm using openSUSE 12.1 x86_64
and i'v built the xen 4.1.2 from source by myself,
the kernel i'm using is "kernel-xen"(3.1.10-1.9-xen) from official repositories.