Re: [PATCH 3/4] x86/kexec(): Reset TDX private memory on platforms with TDX erratum

[Huang, Kai]

On 2/02/2024 8:54 am, Edgecombe, Rick P wrote:
> On Wed, 2024-01-31 at 11:31 +0000, Huang, Kai wrote:
> > Note kexec() can happen at anytime, including when TDX module is
> > being
> > initialized.  Register TDX reboot notifier callback to stop further
> > TDX
> > module initialization.  If there's any ongoing module initialization,
> > wait until it finishes.  This makes sure the TDX module status is
> > stable
> > after the reboot notifier callback, and the later kexec() code can
> > read
> > module status to decide whether PAMTs are stable and available.
>
> I don't see how this works with the crash kernel flavor of kexec. Did
> you look at that scenario?
Hmm right this doesn't work for crash kexec.  Thanks for pointing out.

We need a way that doesn't depend on the reboot notifier.  Previously we 
used a variable to indicate the point where it's possible to have any 
TDX private pages.  I'll switch back to use that.