Re: [Qemu-devel] [PATCH 1/2] spapr_cpu_core: migrate per-CPU data

[David Gibson <david@gibson.dropbear.id.au>]

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On Mon, Jun 18, 2018 at 02:26:35PM +0200, Greg Kurz wrote:
> A per-CPU machine data pointer was recently added to PowerPCCPU. The
> motivation is to to hide platform specific details from the core CPU
> code. This per-CPU data can hold state which is revelant to the guest
> though, eg, Virtual Processor Areas, and we whould migrate this state.
> 
> This patch adds the plumbing so that we can migrate the per-CPU data
> for PAPR guests. We only do this for newer machine types for the sake
> of backword compatibility. No state is migrated for the moment: the
> vmstate_spapr_cpu_state structure will be populated by subsequent
> patches.
> 
> Signed-off-by: Greg Kurz <groug@kaod.org>

Applied, though I fixed some spelling and spacing errors along the way.

> ---
>  hw/ppc/spapr.c                  |    5 +++++
>  hw/ppc/spapr_cpu_core.c         |   27 +++++++++++++++++++++++----
>  include/hw/ppc/spapr_cpu_core.h |    1 +
>  3 files changed, 29 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index db0fb385d4e0..37db3e8bc6ca 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -4116,6 +4116,11 @@ DEFINE_SPAPR_MACHINE(3_0, "3.0", true);
>      {                                                                  \
>          .driver = TYPE_POWERPC_CPU,                                    \
>          .property = "pre-3.0-migration",                              \
> +        .value    = "on",                                              \
> +            },                                                         \
> +    {                                                                  \
> +        .driver = TYPE_SPAPR_CPU_CORE,                                 \
> +        .property = "pre-3.0-migration",                               \
>          .value    = "on",                                              \
>      },
>  
> diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
> index aef3be33a3bb..96d1dfad00e1 100644
> --- a/hw/ppc/spapr_cpu_core.c
> +++ b/hw/ppc/spapr_cpu_core.c
> @@ -129,6 +129,15 @@ static void spapr_cpu_core_unrealize(DeviceState *dev, Error **errp)
>      g_free(sc->threads);
>  }
>  
> +static const VMStateDescription vmstate_spapr_cpu_state = {
> +    .name = "spapr_cpu",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_END_OF_LIST()
> +    },
> +};
> +
>  static void spapr_realize_vcpu(PowerPCCPU *cpu, sPAPRMachineState *spapr,
>                                 Error **errp)
>  {
> @@ -164,7 +173,8 @@ error:
>      error_propagate(errp, local_err);
>  }
>  
> -static PowerPCCPU *spapr_create_vcpu(sPAPRCPUCore *sc, int i, Error **errp)
> +static PowerPCCPU *spapr_create_vcpu(sPAPRCPUCore *sc, int i,
> +                                     sPAPRMachineState *spapr, Error **errp)
>  {
>      sPAPRCPUCoreClass *scc = SPAPR_CPU_CORE_GET_CLASS(sc);
>      CPUCore *cc = CPU_CORE(sc);
> @@ -194,6 +204,10 @@ static PowerPCCPU *spapr_create_vcpu(sPAPRCPUCore *sc, int i, Error **errp)
>      }
>  
>      cpu->machine_data = g_new0(sPAPRCPUState, 1);
> +    if (!sc->pre_3_0_migration) {
> +        vmstate_register(NULL, cs->cpu_index, &vmstate_spapr_cpu_state,
> +                         cpu->machine_data);
> +    }
>  
>      object_unref(obj);
>      return cpu;
> @@ -204,10 +218,13 @@ err:
>      return NULL;
>  }
>  
> -static void spapr_delete_vcpu(PowerPCCPU *cpu)
> +static void spapr_delete_vcpu(PowerPCCPU *cpu, sPAPRCPUCore *sc)
>  {
>      sPAPRCPUState *spapr_cpu = spapr_cpu_state(cpu);
>  
> +    if (!sc->pre_3_0_migration) {
> +        vmstate_unregister(NULL, &vmstate_spapr_cpu_state, cpu->machine_data);
> +    }
>      cpu->machine_data = NULL;
>      g_free(spapr_cpu);
>      object_unparent(OBJECT(cpu));
> @@ -233,7 +250,7 @@ static void spapr_cpu_core_realize(DeviceState *dev, Error **errp)
>  
>      sc->threads = g_new(PowerPCCPU *, cc->nr_threads);
>      for (i = 0; i < cc->nr_threads; i++) {
> -        sc->threads[i] = spapr_create_vcpu(sc, i, &local_err);
> +        sc->threads[i] = spapr_create_vcpu(sc, i, spapr, &local_err);
>          if (local_err) {
>              goto err;
>          }
> @@ -253,7 +270,7 @@ err_unrealize:
>      }
>  err:
>      while (--i >= 0) {
> -        spapr_delete_vcpu(sc->threads[i]);
> +        spapr_delete_vcpu(sc->threads[i], sc);
>      }
>      g_free(sc->threads);
>      error_propagate(errp, local_err);
> @@ -261,6 +278,8 @@ err:
>  
>  static Property spapr_cpu_core_properties[] = {
>      DEFINE_PROP_INT32("node-id", sPAPRCPUCore, node_id, CPU_UNSET_NUMA_NODE_ID),
> +    DEFINE_PROP_BOOL("pre-3.0-migration", sPAPRCPUCore, pre_3_0_migration,
> +                     false),
>      DEFINE_PROP_END_OF_LIST()
>  };
>  
> diff --git a/include/hw/ppc/spapr_cpu_core.h b/include/hw/ppc/spapr_cpu_core.h
> index 8ceea2973a93..9e2821e4b31f 100644
> --- a/include/hw/ppc/spapr_cpu_core.h
> +++ b/include/hw/ppc/spapr_cpu_core.h
> @@ -31,6 +31,7 @@ typedef struct sPAPRCPUCore {
>      /*< public >*/
>      PowerPCCPU **threads;
>      int node_id;
> +    bool pre_3_0_migration; /* older machine don't know about sPAPRCPUState */
>  } sPAPRCPUCore;
>  
>  typedef struct sPAPRCPUCoreClass {
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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