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Date: Thu, 18 Aug 2022 06:58:27 +0200
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: "Xu, Min M" <min.m.xu@intel.com>
Cc: "devel@edk2.groups.io" <devel@edk2.groups.io>
Subject: Re: [edk2-devel] CcProbeLib not working for runtime calls
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On Thu, Aug 18, 2022 at 01:47:37AM +0000, Xu, Min M wrote:
> On August 17, 2022 7:05 PM, Gerd Hoffmann wrote:
> > https://bugzilla.redhat.com/show_bug.cgi?id=2114858
> > 
> > I think the call chain is:
> > 
> > -> linux does efi runtime call
> >   -> some debug message printed
> >     -> OvmfPkg/Library/PlatformDebugLibIoPort/DebugLib.c
> >       -> MdePkg/Library/BaseIoLibIntrinsic (IoWriteFifo8)
> >         -> OvmfPkg/Library/CcProbeLib (CcProbe)
> >           -> page fault when trying to access WorkArea
> > 
> 
> I think this bug shares the same root cause. https://bugzilla.tianocore.org/show_bug.cgi?id=3974

Yes, highly likely this is the same.

> And there is a fix awaiting for review. https://edk2.groups.io/g/devel/message/91132

Hmm.  When the tdx/sev code actually works properly in runtime mode we
should be able to reserve the workarea, mark it as runtime memory
(SetMemorySpaceAttributes) and access it from runtime code, so we don't
need two different ways to figure what CC mode we are running in.

take care,
  Gerd