Re: [RFC][PATCH] pstore: EFI Support

[Borislav Petkov <bp@amd64.org>]

On Tue, May 10, 2011 at 09:11:37AM -0700, Greg KH wrote:
> On Tue, May 10, 2011 at 11:00:44AM -0400, Seiji Aguchi wrote:
> > Description of boot paremeters is following.
> > 
> >  - efi_pstore_enable
> >    enable EFI support of pstore.
> > 
> >  - efi_pstore_len
> >    Sets the buffer size of EFI variable space used by pstore.
> 
> Please don't add new boot parameters if at all possible.  Distros will
> not know to enable them, and users don't know how to either.
> 
> Use sane defaults, and provide ways to override them if needed, but
> don't rely on them for new functionality if at all possible.
> 
> Why would this option ever _not_ be something that should be enabled?

Right, so if I understand this correctly, we want actually to _switch_
to the EFI method if it is safer than APEI. So it should work like this:
if the pstore detects that the system has EFI, it should switch to use
it as a method for writing persistent records to NVRAM.

Btw, is this case of the possibility for APEI of corrupting NVRAM
storage something you actually experienced on a real machine or simply a
conclusion from looking at APEI code doing ioremap()?

Thanks.

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
General Managers: Alberto Bozzo, Andrew Bowd
Registration: Dornach, Gemeinde Aschheim, Landkreis Muenchen
Registergericht Muenchen, HRB Nr. 43632