| Message ID | 152538217073.223014.17347204768561945420.stgit@bahia.lan |
|---|---|
| Headers | show |
| Series | spapr: fix backward migration from POWER9 to POWER8 hosts | expand |
On Thu, May 03, 2018 at 11:16:10PM +0200, Greg Kurz wrote: > 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. Applied to ppc-for-2.13. As you say, these should probably go to the 2.12 and 2.11 stable trees too.
On Fri, 4 May 2018 10:11:02 +1000 David Gibson <david@gibson.dropbear.id.au> wrote: > On Thu, May 03, 2018 at 11:16:10PM +0200, Greg Kurz wrote: > > 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. > > Applied to ppc-for-2.13. As you say, these should probably go to the > 2.12 and 2.11 stable trees too. > Cc'ing qemu-stable then Cheers, -- Greg
On Fri, May 04, 2018 at 07:58:21AM +0200, Greg Kurz wrote: > On Fri, 4 May 2018 10:11:02 +1000 > David Gibson <david@gibson.dropbear.id.au> wrote: > > > On Thu, May 03, 2018 at 11:16:10PM +0200, Greg Kurz wrote: > > > 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. > > > > Applied to ppc-for-2.13. As you say, these should probably go to the > > 2.12 and 2.11 stable trees too. > > > > Cc'ing qemu-stable then Thanks. I'm about to go on leave, so I won't be around to shepherd these into the stable trees any time soon.
On Fri, 4 May 2018 16:37:19 +1000 David Gibson <david@gibson.dropbear.id.au> wrote: > On Fri, May 04, 2018 at 07:58:21AM +0200, Greg Kurz wrote: > > On Fri, 4 May 2018 10:11:02 +1000 > > David Gibson <david@gibson.dropbear.id.au> wrote: > > > > > On Thu, May 03, 2018 at 11:16:10PM +0200, Greg Kurz wrote: > > > > 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. > > > > > > Applied to ppc-for-2.13. As you say, these should probably go to the > > > 2.12 and 2.11 stable trees too. > > > > > > > Cc'ing qemu-stable then > > Thanks. I'm about to go on leave, so I won't be around to shepherd > these into the stable trees any time soon. > No problem. I'll take care of that with Mike. Have a good *disconnected as much as possible* holiday ! :) Cheers, -- Greg
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(-)