Re: [PATCH v2] powerpc/pseries/eeh: Fix pseries_eeh_err_inject

[Narayana Murty N <nnmlinux@linux.ibm.com>]

On 05/09/24 6:33 PM, Michael Ellerman wrote:
> Narayana Murty N <nnmlinux@linux.ibm.com> writes:
>> VFIO_EEH_PE_INJECT_ERR ioctl is currently failing on pseries
>> due to missing implementation of err_inject eeh_ops for pseries.
>> This patch implements pseries_eeh_err_inject in eeh_ops/pseries
>> eeh_ops. Implements support for injecting MMIO load/store error
>> for testing from user space.
>>
>> The check on PCI error type code is moved to platform code, since
>> the eeh_pe_inject_err can be allowed to more error types depending
>> on platform requirement.
>>
>> Signed-off-by: Narayana Murty N <nnmlinux@linux.ibm.com>
>> ---
>>
>> Testing:
>> ========
>> vfio-test [1] by Alex Willamson, was forked and updated to add
>> support inject error on pSeries guest and used to test this
>> patch[2].
>>
>> References:
>> ===========
>> [1] https://github.com/awilliam/tests
>> [2] https://github.com/nnmwebmin/vfio-ppc-tests/tree/vfio-ppc-ex
>>
>> ================
>> Changelog:
>> V1:https://lore.kernel.org/all/20240822082713.529982-1-nnmlinux@linux.ibm.com/
>> - Resolved build issues for ppc64|le_defconfig by moving the
>> pseries_eeh_err_inject() definition outside of the CONFIG_PCI_IOV
>> code block.
>> - New eeh_pe_inject_mmio_error wrapper function added to avoid
>> CONFIG_EEH is not set.
>   
> I don't see why that's necessary?
>
> It's only called from eeh_pseries.c, which is only built for
> PPC_PSERIES, and when PPC_PSERIES=y, EEH is always enabled.
>
>> diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
>> index 91a9fd53254f..8da6b047a4fe 100644
>> --- a/arch/powerpc/include/asm/eeh.h
>> +++ b/arch/powerpc/include/asm/eeh.h
>> @@ -308,7 +308,7 @@ int eeh_pe_reset(struct eeh_pe *pe, int option, bool include_passed);
>>   int eeh_pe_configure(struct eeh_pe *pe);
>>   int eeh_pe_inject_err(struct eeh_pe *pe, int type, int func,
>>   		      unsigned long addr, unsigned long mask);
>> -
>> +int eeh_pe_inject_mmio_error(struct pci_dev *pdev);
>>   /**
>>    * EEH_POSSIBLE_ERROR() -- test for possible MMIO failure.
>>    *
>> @@ -338,6 +338,10 @@ static inline int eeh_check_failure(const volatile void __iomem *token)
>>   	return 0;
>>   }
>>   
>> +static inline int eeh_pe_inject_mmio_error(struct pci_dev *pdev)
>> +{
>> +	return -ENXIO;
>> +}
>>   #define eeh_dev_check_failure(x) (0)
>>   
>>   static inline void eeh_addr_cache_init(void) { }
>> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
>> index d03f17987fca..49ab11a287a3 100644
>> --- a/arch/powerpc/kernel/eeh.c
>> +++ b/arch/powerpc/kernel/eeh.c
>> @@ -1537,10 +1537,6 @@ int eeh_pe_inject_err(struct eeh_pe *pe, int type, int func,
>>   	if (!eeh_ops || !eeh_ops->err_inject)
>>   		return -ENOENT;
>>   
>> -	/* Check on PCI error type */
>> -	if (type != EEH_ERR_TYPE_32 && type != EEH_ERR_TYPE_64)
>> -		return -EINVAL;
>> -
>   
> The change log should mention why it's OK to remove these checks. You
> add the same checks in pseries_eeh_err_inject(), but what about
> pnv_eeh_err_inject() ?
>
> It is OK AFAICS, because pnv_eeh_err_inject() already contains
> equivalent checks, but you should spell that out.
>
> cheers

yes mpe. I do agree, your comments are addressed in V3 posted

here 
https://lore.kernel.org/all/20240909140220.529333-1-nnmlinux@linux.ibm.com/

regards,

Narayana Murty.