[libvirt-users] caps->nguests == 0?

hi, I compiled the libvirt-0.9.10 and started the libvirtd with sudo. Unfortunately, I got an Error, saying 'virDomainDefParseXML unknown OS type hvm'. I debugged it and found in function virCapabilitiesSupportsGuestOSType, the parameter caps->nguests is 0. On the other hand, I tried start the libvirtd with common user, and creating domain with virsh, i found the caps->ngusts is 2 and had one value 'hvm', so it didn't complain the error above, instead, it complained could not load PC BIOS bios.bin. I'd say I searched a lot and people say it's caused by without loading kvm and kvm-intel module. So, I checked and it is loaded. Any tips here?