hw/ppc: Do not re-read the clock on pre_save if doing savevm
A guest with enough RAM, eg. 128G, is likely to detect savevm downtime
and to complain about stalled CPUs. This happens because we re-read
the timebase just before migrating it and we thus don't account for
all the time between VM stop and pre-save.
A very similar situation was already addressed for live migration of
paused guests (commit
d14f33976282). Extend the logic to do the same
with savevm.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=
1893787
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <
160693010619.
1111945.
632640981169395440.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>