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Message-ID: <e183d9b5-eb39-1e08-1d23-831a2df2e0e6@linux.ibm.com>
Date:   Tue, 4 Oct 2022 15:48:08 +0200
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Subject: Re: [PATCH v14 6/6] KVM: s390: pv: module parameter to fence
 asynchronous destroy
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To:     Claudio Imbrenda <imbrenda@linux.ibm.com>, kvm@vger.kernel.org
Cc:     borntraeger@de.ibm.com, frankja@linux.ibm.com, thuth@redhat.com,
        david@redhat.com, linux-s390@vger.kernel.org,
        linux-kernel@vger.kernel.org, scgl@linux.ibm.com, nrb@linux.ibm.com
References: <20220930140150.37463-1-imbrenda@linux.ibm.com>
 <20220930140150.37463-7-imbrenda@linux.ibm.com>
From:   Steffen Eiden <seiden@linux.ibm.com>
In-Reply-To: <20220930140150.37463-7-imbrenda@linux.ibm.com>
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On 9/30/22 16:01, Claudio Imbrenda wrote:
> Add the module parameter "async_destroy", to allow the asynchronous
> destroy mechanism to be switched off. This might be useful for
> debugging purposes.
> 
> The parameter is enabled by default since the feature is opt-in anyway.
> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
LGTM
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>

> ---
>   arch/s390/kvm/kvm-s390.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 7a3bd68efd85..33a53b389cf3 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -209,7 +209,13 @@ unsigned int diag9c_forwarding_hz;
>   module_param(diag9c_forwarding_hz, uint, 0644);
>   MODULE_PARM_DESC(diag9c_forwarding_hz, "Maximum diag9c forwarding per second, 0 to turn off");
>   
> -static int async_destroy;
> +/*
> + * allow asynchronous deinit for protected guests; enable by default since
> + * the feature is opt-in anyway
> + */
> +static int async_destroy = 1;
> +module_param(async_destroy, int, 0444);
> +MODULE_PARM_DESC(async_destroy, "Asynchronous destroy for protected guests");
>   
>   /*
>    * For now we handle at most 16 double words as this is what the s390 base