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

From: Michael Ellerman <[email-masked]>
Date: Thu, 05 Sep 2024 23:03:53 +1000

Narayana Murty N <[email-masked]> 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 <[email-masked]>
> ---
>
> 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/[email-masked]/
> - 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