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

["Huang, Kai" <kai.huang@intel.com>]

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.