In that case, I'd guess that Gleb just forgot to call
virDomainSetMemoryStatsPeriod, perhaps?
I've just performed the same test with
CentOS 7 at the host and CentOS 7
at the guest.
Everything works.
# virsh dommemstat vm1
actual 1048576
swap_in 0
swap_out 0
major_fault 751
minor_fault 3958627
unused 375900
available 1017988
rss 978248
I don't know the reason it doesn't work with ELRepo 3.10.45 kernel but
I'd really like to.
According to
https://bugzilla.redhat.com/show_bug.cgi?id=601690
memoryStats should work at host's side starting from 2.6.32-52.el6 so I
suppose the problem is the guest kernel.
Do you think this could be caused by an old version of virtio_balloon
driver?