Re: [PATCH v11 07/19] KVM: s390: pv: module parameter to fence asynchronous destroy

From: Claudio Imbrenda
Date: Wed Jun 15 2022 - 05:59:59 EST


On Wed, 15 Jun 2022 11:53:17 +0200
Janosch Frank <frankja@xxxxxxxxxxxxx> wrote:

> On 6/3/22 08:56, 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.
> >
> > Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
> > Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
>
> Normally this would be one of the last patches in the series, no?

I need the variable to be already defined, because the subsequent
patches use it to fence things

>
> > ---
> > arch/s390/kvm/kvm-s390.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index 76ad6408cb2c..49e27b5d7c3a 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -206,6 +206,11 @@ 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");
> >
> > +/* allow asynchronous deinit for protected guests, enable by default */
> > +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
> > * kernel handles and stores in the prefix page. If we ever need to go beyond
>