2022-09-30 14:43:44

by Claudio Imbrenda

Subject: [PATCH v14 6/6] KVM: s390: pv: module parameter to fence asynchronous destroy

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 <[email protected]>
Reviewed-by: Janosch Frank <[email protected]>
---
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
--
2.37.3

2022-10-04 14:22:42

by Steffen Eiden

Subject: Re: [PATCH v14 6/6] KVM: s390: pv: module parameter to fence asynchronous destroy

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 <[email protected]>
> Reviewed-by: Janosch Frank <[email protected]>
LGTM
Reviewed-by: Steffen Eiden <[email protected]>

> ---
> 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