Re: [Qemu-devel] [Qemu-stable] [PATCH 28/35] spapr: skip configuration section during migration of older machines

[Greg Kurz]

On Mon, 21 Mar 2016 12:28:26 -0500
Michael Roth <address@hidden> wrote:

> From: Greg Kurz <address@hidden>
> 
> Since QEMU 2.4, we have a configuration section in the migration stream.
> This must be skipped for older machines, like it is already done for x86.
> 
> This patch fixes the migration of pseries-2.3 from/to QEMU 2.3, but it
> breaks migration of the same machine from/to QEMU 2.4/2.4.1/2.5. We do
> that anyway because QEMU 2.3 is likely to be more widely deployed than
> newer QEMU versions.
> 
> Fixes: 61964c23e5ddd5a33f15699e45ce126f879e3e33
> Signed-off-by: Greg Kurz <address@hidden>
> Reviewed-by: Laurent Vivier <address@hidden>
> Reviewed-by: Juan Quintela <address@hidden>
> Signed-off-by: David Gibson <address@hidden>
> (cherry picked from commit 09b5e30da5b19f44768a5429f603caaede216757)
> 
> Conflicts:
>       hw/ppc/spapr.c
> 
> *remove dep on 5013c5474
> 
> Signed-off-by: Michael Roth <address@hidden>
> ---

This will break migration of pseries-2.3 from QEMU 2.5 to QEMU 2.5.1. Maybe
this should be documented somewhere ?

Also, there's a companion patch to allow migration to succeed with manual
intervention on the destination:

commit 902c053d834e3b802ec736f170edf226d4a841ff
Author: Greg Kurz <address@hidden>
Date:   Thu Feb 18 12:32:25 2016 +0100

    migration: allow machine to enforce configuration section migration

Maybe worth to push to stable as well ?

>  hw/ppc/spapr.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 6bfb908..ff1537a 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2327,6 +2327,7 @@ static void spapr_compat_2_3(Object *obj)
>  {
>      savevm_skip_section_footers();
>      global_state_set_optional();
> +    savevm_skip_configuration();
>  }
> 
>  static void spapr_compat_2_2(Object *obj)