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

[Huang, Kai]

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.
	 */

This allows a use case that the caller simply wants to call some SEAMCALL on
local cpu, e.g., IOMMU code may just use below to get some TDX-IO information:

	preempt_disable();
	vmxon();
	tdx_cpu_enable();
	SEAMCALL;
	vmxoff();
	preempt_enable();

Are you OK with this?