Re: [Qemu-devel] [RFC PATCH v1 3/5] spapr: Implement CPUClass::get_migration_id() for PowerPC CPUs

[Greg Kurz <groug@kaod.org>]

On Wed,  6 Jul 2016 14:29:19 +0530
Bharata B Rao <bharata@linux.vnet.ibm.com> wrote:
> cpu_index is used as migration_id by default. For machine type versions
> that set use-migration-id property, cpu_dt_it is returned.
> 

It looks wrong to hijack cpu_dt_id to fix migration.

For pseries-2.7, you need to pass the sum of the index of the core in
spapr->cores and the index of the thread in sc->threads.

All other machines just need to pass the index of the cpu in their
respective arrays, which happens to be equal to cs->cpu_index.

> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> ---
>  target-ppc/translate_init.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
> index efd6b88..9ca2f5e 100644
> --- a/target-ppc/translate_init.c
> +++ b/target-ppc/translate_init.c
> @@ -10359,6 +10359,17 @@ static gchar *ppc_gdb_arch_name(CPUState *cs)
>  #endif
>  }
>  
> +static int ppc_cpu_get_migration_id(CPUState *cs)
> +{
> +    PowerPCCPU *cpu = POWERPC_CPU(cs);
> +
> +    if (cs->use_migration_id) {
> +        return (int) cpu->cpu_dt_id;
> +    } else {
> +        return cs->cpu_index;
> +    }
> +}
> +
>  static void ppc_cpu_class_init(ObjectClass *oc, void *data)
>  {
>      PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
> @@ -10412,6 +10423,7 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data)
>  #ifndef CONFIG_USER_ONLY
>      cc->virtio_is_big_endian = ppc_cpu_is_big_endian;
>  #endif
> +    cc->get_migration_id = ppc_cpu_get_migration_id;
>  
>      dc->fw_name = "PowerPC,UNKNOWN";
>  }