Re: [PATCH 3/7] hw/ppc: Handle stash command in PowerNV SBE

[Aditya Gupta <adityag@linux.ibm.com>]

On 11/03/25 10:20, Harsh Prateek Bora wrote:

>
>> <...snip...>
>>
>> --- a/hw/ppc/pnv_sbe.c
>> +++ b/hw/ppc/pnv_sbe.c
>> @@ -82,6 +82,8 @@
>>   #define SBE_CONTROL_REG_S0              PPC_BIT(14)
>>   #define SBE_CONTROL_REG_S1              PPC_BIT(15)
>>   +static uint64_t mpipl_skiboot_base = 0x30000000 /*default 
>> SKIBOOT_BASE*/;
>> +
>>   static void pnv_sbe_set_host_doorbell(PnvSBE *sbe, uint64_t val)
>>   {
>>       val &= SBE_HOST_RESPONSE_MASK; /* Is this right? What does HW 
>> do? */
>> @@ -281,6 +283,29 @@ static void do_sbe_msg(PnvSBE *sbe)
>>               timer_del(sbe->timer);
>>           }
>>           break;
>> +    case SBE_CMD_STASH_MPIPL_CONFIG:
>> +        /* key = sbe->mbox[1] */
>> +        switch (sbe->mbox[1]) {
>> +        case SBE_STASH_KEY_SKIBOOT_BASE:
>> +            mpipl_skiboot_base = sbe->mbox[2];
>> +            qemu_log_mask(LOG_UNIMP,
>> +                "Stashing skiboot base: 0x%lx\n", mpipl_skiboot_base);
>> +
>> +            /*
>> +             * Set the response register.
>> +             *
>> +             * Currently setting the same sequence number in
>> +             * response as we got in the request.
>> +             */
>> +            sbe->mbox[4] = sbe->mbox[0];    /* sequence number */
>> +            pnv_sbe_set_host_doorbell(sbe,
>> +                    sbe->host_doorbell | SBE_HOST_RESPONSE_WAITING);
>> +
>> +            break;
>> +        default:
>> +            qemu_log_mask(LOG_UNIMP, "SBE Unimplemented command: 
>> 0x%x\n", cmd);
>
> Unimplemented SBE_CMD_STASH_MPIPL_CONFIG key ?

Got it. Thanks for the reword suggestion, will do it.


Thanks,

- Aditya G

>
>> +        }
>> +        break;
>>       default:
>>           qemu_log_mask(LOG_UNIMP, "SBE Unimplemented command: 
>> 0x%x\n", cmd);
>>       }
>> diff --git a/include/hw/ppc/pnv_sbe.h b/include/hw/ppc/pnv_sbe.h
>> index b6b378ad14c7..f6cbcf990ed9 100644
>> --- a/include/hw/ppc/pnv_sbe.h
>> +++ b/include/hw/ppc/pnv_sbe.h
>> @@ -53,4 +53,7 @@ struct PnvSBEClass {
>>       const MemoryRegionOps *xscom_mbox_ops;
>>   };
>>   +/* Helper to access stashed SKIBOOT_BASE */
>> +bool pnv_sbe_mpipl_skiboot_base(void);
>> +
>>   #endif /* PPC_PNV_SBE_H */