Re: [PATCH v3 05/12] ppc/pnv: turn PnvPHB4 into a PnvPHB backend

[Daniel Henrique Barboza <danielhb413@gmail.com>]

On 7/27/22 14:41, Frederic Barrat wrote:
> 
> 
> On 24/06/2022 10:49, Daniel Henrique Barboza wrote:
> 
>> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
>> index 1df91971b8..b7273f386e 100644
>> --- a/hw/ppc/pnv.c
>> +++ b/hw/ppc/pnv.c
>> @@ -672,7 +672,14 @@ static void pnv_chip_power8_pic_print_info(PnvChip *chip, Monitor *mon)
>>   static int pnv_chip_power9_pic_print_info_child(Object *child, void *opaque)
>>   {
>>       Monitor *mon = opaque;
>> -    PnvPHB4 *phb4 = (PnvPHB4 *) object_dynamic_cast(child, TYPE_PNV_PHB4);
>> +    PnvPHB *phb =  (PnvPHB *) object_dynamic_cast(child, TYPE_PNV_PHB);
>> +    PnvPHB4 *phb4;
>> +
>> +    if (!phb) {
>> +        return 0;
>> +    }
>> +
>> +    phb4 = (PnvPHB4 *)phb->backend;
>>       if (phb4) {
>>           pnv_phb4_pic_print_info(phb4, mon);
> 
> 
> The full code in pnv_chip_power9_pic_print_info_child() looks like this:
> 
>      PnvPHB *phb =  (PnvPHB *) object_dynamic_cast(child, TYPE_PNV_PHB);
>      PnvPHB4 *phb4;
> 
>      if (!phb) {
>          return 0;
>      }
> 
>      phb4 = (PnvPHB4 *)phb->backend;
> 
>      if (phb4) {
>          pnv_phb4_pic_print_info(phb4, mon);
>      }
> 
> Which is correct. However, if I want to nitpick, phb->backend is defined when the PnvPHB object is realized, so I don't think we can get here with the pointer being null, so we could remove the second if statement for readability. The reason I mention it is that we don't take that much care in the pnv_chip_power8_pic_print_info() function just above, so it looks a bit odd.

Good point. I changed it to look like this:


static int pnv_chip_power9_pic_print_info_child(Object *child, void *opaque)
{
     Monitor *mon = opaque;
     PnvPHB *phb =  (PnvPHB *) object_dynamic_cast(child, TYPE_PNV_PHB);

     if (!phb) {
         return 0;
     }

     pnv_phb4_pic_print_info(PNV_PHB4(phb->backend), mon);

     return 0;
}

phb->backend being either NULL or not a PHB4 object is serious enough to assert
out, so the PNV_PHB4() macro seems justified.


Thanks,


Daniel

> 
> In any case:
> Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
> 
>    Fred
> 
> 
> 
> 
>> @@ -2122,8 +2129,14 @@ static void pnv_machine_power9_class_init(ObjectClass *oc, void *data)
>>       PnvMachineClass *pmc = PNV_MACHINE_CLASS(oc);
>>       static const char compat[] = "qemu,powernv9\0ibm,powernv";
>> +    static GlobalProperty phb_compat[] = {
>> +        { TYPE_PNV_PHB, "version", "4" },
>> +    };
>> +
>>       mc->desc = "IBM PowerNV (Non-Virtualized) POWER9";
>>       mc->default_cpu_type = POWERPC_CPU_TYPE_NAME("power9_v2.0");
>> +    compat_props_add(mc->compat_props, phb_compat, G_N_ELEMENTS(phb_compat));
>> +
>>       xfc->match_nvt = pnv_match_nvt;
>>       mc->alias = "powernv";
>> @@ -2140,8 +2153,13 @@ static void pnv_machine_power10_class_init(ObjectClass *oc, void *data)
>>       XiveFabricClass *xfc = XIVE_FABRIC_CLASS(oc);
>>       static const char compat[] = "qemu,powernv10\0ibm,powernv";
>> +    static GlobalProperty phb_compat[] = {
>> +        { TYPE_PNV_PHB, "version", "5" },
>> +    };
>> +
>>       mc->desc = "IBM PowerNV (Non-Virtualized) POWER10";
>>       mc->default_cpu_type = POWERPC_CPU_TYPE_NAME("power10_v2.0");
>> +    compat_props_add(mc->compat_props, phb_compat, G_N_ELEMENTS(phb_compat));
>>       pmc->compat = compat;
>>       pmc->compat_size = sizeof(compat);
>> diff --git a/include/hw/pci-host/pnv_phb4.h b/include/hw/pci-host/pnv_phb4.h
>> index 90843ac3a9..f22253358f 100644
>> --- a/include/hw/pci-host/pnv_phb4.h
>> +++ b/include/hw/pci-host/pnv_phb4.h
>> @@ -18,6 +18,7 @@
>>   typedef struct PnvPhb4PecState PnvPhb4PecState;
>>   typedef struct PnvPhb4PecStack PnvPhb4PecStack;
>>   typedef struct PnvPHB4 PnvPHB4;
>> +typedef struct PnvPHB PnvPHB;
>>   typedef struct PnvChip PnvChip;
>>   /*
>> @@ -78,7 +79,9 @@ OBJECT_DECLARE_SIMPLE_TYPE(PnvPHB4, PNV_PHB4)
>>   #define PCI_MMIO_TOTAL_SIZE        (0x1ull << 60)
>>   struct PnvPHB4 {
>> -    PCIExpressHost parent_obj;
>> +    DeviceState parent;
>> +
>> +    PnvPHB *phb_base;
>>       uint32_t chip_id;
>>       uint32_t phb_id;