Memory statistic question

Hello,

I'm trying to get memory usage statistic inside a guest machine using virDomainMemoryStats function at libvirt.
According to http://libvirt.org/html/libvirt-libvirt.html#virDomainMemoryStatTags the structure could have a lot of useful memory statistic but the amount of parameters depends on the hypervisor and the driver. However using KVM I'm able to get VIR_DOMAIN_MEMORY_STAT_ACTUAL_BALLOON and VIR_DOMAIN_MEMORY_STAT_RSS.

Am I right it is not possible to get additional info such as used/unused memory inside a guest machine in case of KVM?