Re: [PATCH 1/3] powerpc/pseries: Set UNISOLATE on dlpar_memory_remove_by_ic() error

[David Gibson <david@gibson.dropbear.id.au>]

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On Fri, Apr 30, 2021 at 09:09:15AM -0300, Daniel Henrique Barboza wrote:
> As previously done in dlpar_cpu_remove() for CPUs, this patch changes
> dlpar_memory_remove_by_ic() to unisolate the LMB DRC when the LMB is
> failed to be removed. The hypervisor, seeing a LMB DRC that was supposed
> to be removed being unisolated instead, can do error recovery on its
> side.
> 
> This change is done in dlpar_memory_remove_by_ic() only because, as of
> today, only QEMU is using this code path for error recovery (via the
> PSERIES_HP_ELOG_ID_DRC_IC event). phyp treats it as a no-op.
> 
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  arch/powerpc/platforms/pseries/hotplug-memory.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
> index 8377f1f7c78e..bb98574a84a2 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -551,6 +551,13 @@ static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
>  			if (!drmem_lmb_reserved(lmb))
>  				continue;
>  
> +			/*
> +			 * Setting the isolation state of an UNISOLATED/CONFIGURED
> +			 * device to UNISOLATE is a no-op, but the hypervisor can
> +			 * use it as a hint that the LMB removal failed.
> +			 */
> +			dlpar_unisolate_drc(lmb->drc_index);
> +
>  			rc = dlpar_add_lmb(lmb);
>  			if (rc)
>  				pr_err("Failed to add LMB, drc index %x\n",

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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