[libvirt] virDomainMemoryStats call

Hi, I'm using the API virDomainMemoryStats to fetch memory stats for a domain/guest on Fedora 16/RHEL 6.3 . I don't get these counters filled up VIR_DOMAIN_MEMORY_STAT_UNUSED, VIR_DOMAIN_MEMORY_STAT_ACTUAL_BALLOON,VIR_DOMAIN_MEMORY_STAT_AVAILABLE , VIR_DOMAIN_MEMORY_STAT_MAJOR_FAULT and VIR_DOMAIN_MEMORY_STAT_MINOR_FAULT. The version of libvirt 0.9.11 on Fedora 16 . How to get all the counters filled up ? Should I take a specific version of qemu or should I do some config settings so that these values are filled up ? P.S. Please copy me in reply Regards, Navin Parakkal HP Software