QEMU 2.4 broke the migration of old pseries machine with the addition
of configuration sections, which are sent unconditionally.
This series tries to fix the issue by providing knobs to control submission
and reception of configuration sections. It is an alternative to simply
skipping configuration for older machines (as it done for x86) because we
don't want to break migration from QEMU 2.4 either.
Patches 1 and 2 allow to migrate pseries-2.3 from QEMU 2.3.
Patch 3 is a tentative to support backward migration to QEMU 2.3,
but it needs manual intervention.
With this series, I could migrate a pseries-2.3 from QEMU 2.3 or QEMU 2.4
to current head without manual intervention. I could then migrate it back
either to QEMU 2.3 with suppress-config-section=on or to QEMU 2.4 without
manual intervention.
---
Greg Kurz (3):
migration: allow configuration section to be optional
spapr: fix migration of older pseries
migration: allow to suppress configuration section submission
hw/core/machine.c | 43 +++++++++++++++++++++++++++++++++++++++++++
hw/ppc/spapr.c | 10 ++++++++++
include/hw/boards.h | 2 ++
migration/savevm.c | 29 ++++++++++++++++++++++-------
qemu-options.hx | 4 +++-
5 files changed, 80 insertions(+), 8 deletions(-)
---
Greg
