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* [Qemu-devel] [PATCH 0/3] spapr: fix backward migration from POWER9 to POWER8 hosts
@ 2018-05-03 21:16 Greg Kurz
  2018-05-03 21:16 ` [Qemu-devel] [PATCH 1/3] target/ppc: always set PPC_MEM_TLBIE in pre 2.8 migration hack Greg Kurz
                   ` (3 more replies)
  0 siblings, 4 replies; 11+ messages in thread
From: Greg Kurz @ 2018-05-03 21:16 UTC (permalink / raw)
  To: qemu-devel
  Cc: qemu-ppc, David Gibson, Laurent Vivier, Cédric Le Goater,
	Suraj Jitindar Singh, Bharata B Rao

Hi,

It is expected to be able to migrate a guest started with

     -machine max-cpu-compat=power8

from a POWER9 host to a POWER8 host. It works with recent QEMU versions,
but it is badly broken if the destination runs QEMU 2.7 or older.

This can cause problems in cloud environments that still have systems with
older QEMU versions, eg, hosts running ubuntu LTS 16.04.4 (QEMU 2.5) which
are likely to stay around until admins could transition to some newer OS.

This series was lightly tested, but the patches are simple enough, so I'm
confident they shouldn't break anything :)

Please review as I'd like these to go to QEMU 2.11.2 as well.

--
Greg

---

Greg Kurz (3):
      target/ppc: always set PPC_MEM_TLBIE in pre 2.8 migration hack
      spapr: don't migrate "spapr_option_vector_ov5_cas" to pre 2.8 machines
      spapr: don't advertise radix GTSE if max-compat-cpu < power9


 hw/ppc/spapr.c       |   19 +++++++++++++------
 target/ppc/machine.c |    5 +++++
 2 files changed, 18 insertions(+), 6 deletions(-)

^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2018-05-04  7:02 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-05-03 21:16 [Qemu-devel] [PATCH 0/3] spapr: fix backward migration from POWER9 to POWER8 hosts Greg Kurz
2018-05-03 21:16 ` [Qemu-devel] [PATCH 1/3] target/ppc: always set PPC_MEM_TLBIE in pre 2.8 migration hack Greg Kurz
2018-05-04  0:12   ` David Gibson
2018-05-04  5:54     ` Greg Kurz
2018-05-04  6:01       ` David Gibson
2018-05-03 21:16 ` [Qemu-devel] [PATCH 2/3] spapr: don't migrate "spapr_option_vector_ov5_cas" to pre 2.8 machines Greg Kurz
2018-05-03 21:16 ` [Qemu-devel] [PATCH 3/3] spapr: don't advertise radix GTSE if max-compat-cpu < power9 Greg Kurz
2018-05-04  0:11 ` [Qemu-devel] [PATCH 0/3] spapr: fix backward migration from POWER9 to POWER8 hosts David Gibson
2018-05-04  5:58   ` Greg Kurz
2018-05-04  6:37     ` David Gibson
2018-05-04  7:01       ` Greg Kurz

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