Re: [PATCH v12 07/22] x86/virt/tdx: Add skeleton to enable TDX on demand

From: Peter Zijlstra
Date: Wed Jun 28 2023 - 09:36:42 EST


On Wed, Jun 28, 2023 at 12:28:12AM +0000, Huang, Kai wrote:
> On Tue, 2023-06-27 at 22:37 +0000, Huang, Kai wrote:
> > > >
> > > > +/*
> > > > + * Do the module global initialization if not done yet.
> > > > + * It's always called with interrupts and preemption disabled.
> > > > + */
> > >
> > > If interrupts are always disabled why do you need _irqsave()?
> > >
> >
> > I'll remove the _irqsave().
> >
> > AFAICT Isaku preferred this for additional security, but this is not
> > necessary.
> >
> >
>
> Damn. I think we can change the comment to say this function is called with
> preemption being disabled, but _can_ be called with interrupt disabled. And we
> keep using the _irqsave() version.
>
> /*
> * Do the module global initialization if not done yet. It's always
> * called with preemption disabled and can be called with interrupts
> * disabled.
> */

That's still not explaining *why*, what you want to say is:

Can be called locally or through an IPI function call.