Re: [Qemu-ppc] [PATCH v5 25/36] spapr: set the interrupt presenter at reset

[Cédric Le Goater]

On 11/29/18 5:03 AM, David Gibson wrote:
> On Fri, Nov 16, 2018 at 11:57:18AM +0100, Cédric Le Goater wrote:
>> Currently, the interrupt presenter of the VPCU is set at realize
>> time. Setting it at reset will become useful when the new machine
>> supporting both interrupt modes is introduced. In this machine, the
>> interrupt mode is chosen at CAS time and activated after a reset.
>>
>> Signed-off-by: Cédric Le Goater <address@hidden>
>> ---
>>  include/hw/ppc/spapr_cpu_core.h |  2 ++
>>  hw/ppc/spapr_cpu_core.c         | 26 ++++++++++++++++++++++++++
>>  hw/ppc/spapr_irq.c              | 11 +++++++++++
>>  3 files changed, 39 insertions(+)
>>
>> diff --git a/include/hw/ppc/spapr_cpu_core.h 
>> b/include/hw/ppc/spapr_cpu_core.h
>> index 9e2821e4b31f..fc8ea9021656 100644
>> --- a/include/hw/ppc/spapr_cpu_core.h
>> +++ b/include/hw/ppc/spapr_cpu_core.h
>> @@ -53,4 +53,6 @@ static inline sPAPRCPUState *spapr_cpu_state(PowerPCCPU 
>> *cpu)
>>      return (sPAPRCPUState *)cpu->machine_data;
>>  }
>>  
>> +void spapr_cpu_core_set_intc(PowerPCCPU *cpu, const char *intc_type);
>> +
>>  #endif
>> diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
>> index 1811cd48db90..529de0b6b9c8 100644
>> --- a/hw/ppc/spapr_cpu_core.c
>> +++ b/hw/ppc/spapr_cpu_core.c
>> @@ -398,3 +398,29 @@ static const TypeInfo spapr_cpu_core_type_infos[] = {
>>  };
>>  
>>  DEFINE_TYPES(spapr_cpu_core_type_infos)
>> +
>> +typedef struct ForeachFindIntCArgs {
>> +    const char *intc_type;
>> +    Object *intc;
>> +} ForeachFindIntCArgs;
>> +
>> +static int spapr_cpu_core_find_intc(Object *child, void *opaque)
>> +{
>> +    ForeachFindIntCArgs *args = opaque;
>> +
>> +    if (object_dynamic_cast(child, args->intc_type)) {
>> +        args->intc = child;
>> +    }
>> +
>> +    return args->intc != NULL;
>> +}
>> +
>> +void spapr_cpu_core_set_intc(PowerPCCPU *cpu, const char *intc_type)
>> +{
>> +    ForeachFindIntCArgs args = { intc_type, NULL };
>> +
>> +    object_child_foreach(OBJECT(cpu), spapr_cpu_core_find_intc, &args);
>> +    g_assert(args.intc);
> 
> We could create some extra links on the cpu to avoid scanning all the
> children, but I guess that's a refinement.

yes. Like an extra ->intc for xive. but as we can have only one interrupt
controller active, having only one presenter per CPU seems reasonable. 

> Then again.. what do we actually use the cpu->intc pointer for in XIVE
> context?  

yes for the TIMA MMIOs and also when running the matching algo in the XIVE 
presenter.

C.

> I had a feeling because of the different way notifications
> are handled we might not ever need to go from a cpu handle to the
> associated TCTX.
>
> 
>> +    cpu->intc = args.intc;
>> +}
>> diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
>> index 984c6d60cd9f..969efad7e6e9 100644
>> --- a/hw/ppc/spapr_irq.c
>> +++ b/hw/ppc/spapr_irq.c
>> @@ -218,6 +218,11 @@ static int spapr_irq_post_load_xics(sPAPRMachineState 
>> *spapr, int version_id)
>>  
>>  static void spapr_irq_reset_xics(sPAPRMachineState *spapr, Error **errp)
>>  {
>> +    CPUState *cs;
>> +
>> +    CPU_FOREACH(cs) {
>> +        spapr_cpu_core_set_intc(POWERPC_CPU(cs), spapr->icp_type);
>> +    }
>>  }
>>  
>>  #define SPAPR_IRQ_XICS_NR_IRQS     0x1000
>> @@ -370,6 +375,12 @@ static int spapr_irq_post_load_xive(sPAPRMachineState 
>> *spapr, int version_id)
>>  
>>  static void spapr_irq_reset_xive(sPAPRMachineState *spapr, Error **errp)
>>  {
>> +    CPUState *cs;
>> +
>> +    CPU_FOREACH(cs) {
>> +        spapr_cpu_core_set_intc(POWERPC_CPU(cs), spapr->xive_tctx_type);
>> +    }
>> +
>>      spapr_xive_mmio_map(spapr->xive);
>>  }
>>  
>