tree e3294ac81369b393769a51b9d41fb4c9384a9d3e
parent 7c8b7248261bfa5e54eff1715b699caa8b3f1d77
author Ján Tomko <jtomko@redhat.com> 1400663027 +0200
committer Michael S. Tsirkin <mst@redhat.com> 1401011218 +0300

virtio-balloon: return empty data when no stats are available

If the guest hasn't updated the stats yet, instead of returning
an error, return '-1' for the stats and '0' as 'last-update'.

This lets applications ignore this without parsing the error message.

Related libvirt patch and discussion:
https://www.redhat.com/archives/libvir-list/2014-May/msg00460.html

Tested against current upstream libvirt - stat reporting works and
it no longer logs errors when the stats are queried on domain startup.
(Note: libvirt doesn't use the last-update field for anything yet)

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>