[libvirt] Getting memory usage info for domains with balloon driver disabled

[Tomasz Barański]

Hello,

I'm looking for a way to read guest memory usage information (RAM used,
RAM available) for VMs with balloon driver disabled.

oVirt used to read that information using ovirt guest agent, but OGA is no
longer used (and not even available for RHEL8).

I've seen that there was a discussion about adding it to the QEMU guest
agent a couple years back[1] but it has not been implemented.

dominfo doesn't help:

    # virsh dominfo 306c001c-f569-4afa-b024-81135c566a73 | grep memory
    Max memory:     1048576 KiB
    Used memory:    1048576 KiB

dommemstat doesn't help:

    # virsh dommemstat 306c001c-f569-4afa-b024-81135c566a73
    rss 1049432

Neither does domstats.

Is there any other way to get the info?


[1] https://bugzilla.redhat.com/show_bug.cgi?id=1101915


Tomo