Hi Jian,

Not aware this comments before I send out V2 patch, will include this info in 
commit message when I check in the code.

Thanks,
Eric
> -----Original Message-----
> From: Wang, Jian J
> Sent: Tuesday, October 9, 2018 10:03 AM
> To: edk2-devel <edk2-devel-boun...@lists.01.org>; Dong, Eric
> <eric.d...@intel.com>; edk2-devel@lists.01.org
> Cc: Ni, Ruiyu <ruiyu...@intel.com>; Laszlo Ersek <ler...@redhat.com>
> Subject: RE: [Patch] UefiCpuPkg/S3Resume2Pei: disable paging before
> creating new page table.
> 
> Forgot one thing: this issue is caused by introducing of PEI stack guard so
> please add the revision id of related check in for references in message.
> 
> Regards,
> Jian
> 
> 
> > -----Original Message-----
> > From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org]
> > Sent: Tuesday, October 09, 2018 9:59 AM
> > To: Dong, Eric <eric.d...@intel.com>; edk2-devel@lists.01.org
> > Cc: Ni, Ruiyu <ruiyu...@intel.com>; Laszlo Ersek <ler...@redhat.com>
> > Subject: Re: [edk2] [Patch] UefiCpuPkg/S3Resume2Pei: disable paging
> > before creating new page table.
> >
> > Thanks for fixing this issue.
> >
> > Reviewed-by: Jian J Wang <jian.j.w...@intel.com>
> >
> > > -----Original Message-----
> > > From: Dong, Eric
> > > Sent: Tuesday, October 09, 2018 9:51 AM
> > > To: edk2-devel@lists.01.org
> > > Cc: Ni, Ruiyu <ruiyu...@intel.com>; Laszlo Ersek
> > > <ler...@redhat.com>; Wang, Jian J <jian.j.w...@intel.com>
> > > Subject: [Patch] UefiCpuPkg/S3Resume2Pei: disable paging before
> > > creating
> > new
> > > page table.
> > >
> > > PEI Stack Guard needs to enable paging. This might cause #GP in the
> > > transition from 32-bit PEI to 64-bit SMM due to the code trying to
> > > write CR3 register with PML4 page table while the processor is
> > > enabled with PAE paging.
> > >
> > > Simply disabling paging before updating CR3 can solve this conflict.
> > >
> > > Change-Id: I99bfdba5daa48a95a4c4ef97eeca1af086558957
> > > Cc: Ruiyu Ni <ruiyu...@intel.com>
> > > Cc: Laszlo Ersek <ler...@redhat.com>
> > > Cc: Jian J Wang <jian.j.w...@intel.com>
> > > Contributed-under: TianoCore Contribution Agreement 1.1
> > > Signed-off-by:Eric Dong <eric.d...@intel.com>
> > > Signed-off-by: Eric Dong <eric.d...@intel.com>
> > > ---
> > >  UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume.c       | 7 +++++++
> > >  UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf | 1 +
> > >  2 files changed, 8 insertions(+)
> > >
> > > diff --git a/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume.c
> > > b/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume.c
> > > index f164c1713b..b3bf56e13d 100644
> > > --- a/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume.c
> > > +++ b/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume.c
> > > @@ -1105,6 +1105,13 @@ S3RestoreConfig2 (
> > >        //
> > >        SetInterruptState (InterruptStatus);
> > >
> > > +      if (PcdGetBool (PcdCpuStackGuard)) {
> > > +        //
> > > +        // Paging already been enabled, to avoid conflict configuration,
> > > +        // disable paging first anyway.
> > > +        //
> > > +        AsmWriteCr0 (AsmReadCr0 () & (~BIT31));
> > > +      }
> > >        AsmWriteCr3 ((UINTN)SmmS3ResumeState->SmmS3Cr3);
> > >
> > >        //
> > > diff --git a/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf
> > > b/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf
> > > index 6ce1bf944c..0f131d19df 100644
> > > --- a/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf
> > > +++ b/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf
> > > @@ -90,6 +90,7 @@
> > >  [Pcd]
> > >    gEfiMdeModulePkgTokenSpaceGuid.PcdUse1GPageTable  ##
> > > SOMETIMES_CONSUMES
> > >
> >
> gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrM
> ask
> > > ## CONSUMES
> > > +  gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard                       
> > > ##
> > > CONSUMES
> > >
> > >  [Depex]
> > >    TRUE
> > > --
> > > 2.15.0.windows.1
> >
> > _______________________________________________
> > edk2-devel mailing list
> > edk2-devel@lists.01.org
> > https://lists.01.org/mailman/listinfo/edk2-devel
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