Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove 4GB memory WA

["Guo Dong" <guo.dong@intel.com>]

Great. Thanks Patrick for the quick test.

Here is my thought on the UEFI Payload works on 4GB:
UefiPayloadPkg tries to provides a generic UEFI payload impl with minimum hard-coded values.
If UEFI payload could not work since a platform specific limitation, user could change their UEFI payload to work under 4GB. E.g.
a). Mark memory above 4GB as reserved in Payload entry, and update the memory attribute (using memory test driver) later.
b). or set some memory type information PCDs

If UEFI payload has some common issue when it is dispatched above 4GB, we could apply the option B if required.

BTW, current 32bit UEFI payload is not supported, and I don't think it supports memory above 4GB. 

Thanks,
Guo

> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Patrick
> Rudolph
> Sent: Monday, February 22, 2021 11:06 AM
> To: Dong, Guo <guo.dong@intel.com>
> Cc: Ma, Maurice <maurice.ma@intel.com>; Dong, Eric <eric.dong@intel.com>;
> Ni, Ray <ray.ni@intel.com>; devel@edk2.groups.io; You, Benjamin
> <benjamin.you@intel.com>
> Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry: Remove
> 4GB memory WA
> 
> Hi Guo,
> I tested it and it works fine with your patch. The crash is gone.
> 
> BTW: Are there are other possible side effects with placing memory
> above 4GB? Like 32bit UEFI drivers or Option ROMs malfunctioning?
> 
> Regards,
> Patrick
> 
> On Mon, Feb 22, 2021 at 6:10 PM Dong, Guo <guo.dong@intel.com> wrote:
> >
> >
> > Hi Patrick,
> > Thank you for the test and root-cause the issues.
> > Could you try if this patch works with "gdtPtr.Base = (UINTN)(VOID*) gdt;"?
> > I didn't see this issue when I tested SBL with UEFI payload on QEMU and a
> real platform.
> > I guess there is something that could make AllocateRuntimePool to allocate
> memory below 4GB while CpuDxe is dispatched above 4GB.
> >
> > Thanks,
> > Guo
> >
> > > -----Original Message-----
> > > From: Ma, Maurice <maurice.ma@intel.com>
> > > Sent: Monday, February 22, 2021 9:50 AM
> > > To: Patrick Rudolph <patrick.rudolph@9elements.com>; Dong, Guo
> > > <guo.dong@intel.com>; Dong, Eric <eric.dong@intel.com>; Ni, Ray
> > > <ray.ni@intel.com>
> > > Cc: devel@edk2.groups.io; You, Benjamin <benjamin.you@intel.com>
> > > Subject: RE: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
> Remove
> > > 4GB memory WA
> > >
> > > Hi, Ray and Eric,
> > >
> > > Is there any reason why the GDT base was typecast to UINT32 in CpuDxe
> driver ?
> > > In x64 long mode, the GDT base is actually 64bit.   Typecasting will zero out
> the
> > > high 32bit address.
> > > To me the correct code seems to be something like:
> > >       gdtPtr.Base = (UINTN)(VOID*) gdt;
> > >
> > > Thanks
> > > Maurice
> > > > -----Original Message-----
> > > > From: Patrick Rudolph <patrick.rudolph@9elements.com>
> > > > Sent: Monday, February 22, 2021 7:43
> > > > To: Dong, Guo <guo.dong@intel.com>
> > > > Cc: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>; You,
> > > > Benjamin <benjamin.you@intel.com>
> > > > Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
> > > > Remove 4GB memory WA
> > > >
> > > > Hi Guo,
> > > > I tested on 078400ee15e7b250e4dfafd840c2e0c19835e16b and run it in
> > > > QEMU.
> > > > The problem seems to be here, as gdt is allocated > 4GiB:
> > > > gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;
> > > >
> > > > Regards,
> > > > Patrick
> > > >
> > > > On Mon, Feb 22, 2021 at 3:59 PM Dong, Guo <guo.dong@intel.com>
> wrote:
> > > > >
> > > > >
> > > > > Hi Patrick,
> > > > > Please make sure you are using latest master when testing this patch.
> > > > > That issue should be fix be this patch:
> > > > > UefiCpuPkg/CpuDxe: Fix boot error (commit:
> > > > > ebfe2d3eb5ac7fd92d74011edb31303a181920c7)
> > > > > And there is similar fix in another place as below:
> > > > > UefiCpuPkg/MpInitLib: Fix a hang in above 4GB case (commit:
> > > > > edd74ad3ad79b855f76d9cf60a96c405cb3e863b)
> > > > >
> > > > > Thanks,
> > > > > Guo
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of
> > > > > > Patrick Rudolph
> > > > > > Sent: Monday, February 22, 2021 7:04 AM
> > > > > > To: devel@edk2.groups.io; Ma, Maurice <maurice.ma@intel.com>
> > > > > > Cc: Dong, Guo <guo.dong@intel.com>; You, Benjamin
> > > > > > <benjamin.you@intel.com>
> > > > > > Subject: Re: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
> > > > > > Remove 4GB memory WA
> > > > > >
> > > > > > This patch breaks booting on master.
> > > > > > In CpuDxe.efi / InitGlobalDescriptorTable as the GDT pointer is
> > > > > > casted to 32bits.
> > > > > >
> > > > > > Regards,
> > > > > > Patrick
> > > > > >
> > > > > > On Fri, Feb 19, 2021 at 3:12 AM Ma, Maurice
> <maurice.ma@intel.com>
> > > > wrote:
> > > > > > >
> > > > > > > Reviewed-by:  Maurice Ma <maurice.ma@intel.com>
> > > > > > >
> > > > > > > Regards
> > > > > > > Maurice
> > > > > > >
> > > > > > > > -----Original Message-----
> > > > > > > > From: Dong, Guo <guo.dong@intel.com>
> > > > > > > > Sent: Sunday, February 14, 2021 21:13
> > > > > > > > To: devel@edk2.groups.io
> > > > > > > > Cc: Ma, Maurice <maurice.ma@intel.com>; You, Benjamin
> > > > > > > > <benjamin.you@intel.com>
> > > > > > > > Subject: [edk2-devel] [PATCH] UefiPayloadPkg/UefiPayloadEntry:
> > > > > > > > Remove 4GB memory WA
> > > > > > > >
> > > > > > > > Previous it would hang in CpuDxe if DXE drivers are dispatched
> above
> > > > 4GB.
> > > > > > > > Now remove the work around since the fixed in CpuDxe are
> merged.
> > > > > > > >
> > > > > > > > Signed-off-by: Guo Dong <guo.dong@intel.com>
> > > > > > > > ---
> > > > > > > >  UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c | 5 -----
> > > > > > > >  1 file changed, 5 deletions(-)
> > > > > > > >
> > > > > > > > diff --git a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
> > > > > > > > b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
> > > > > > > > index 805f5448d9..c403b0a80a 100644
> > > > > > > > --- a/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
> > > > > > > > +++ b/UefiPayloadPkg/UefiPayloadEntry/UefiPayloadEntry.c
> > > > > > > > @@ -40,11 +40,6 @@ MemInfoCallback (
> > > > > > > >
> EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
> > > > > > > >               EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE;
> > > > > > > >
> > > > > > > > -  if (Base >= BASE_4GB ) {
> > > > > > > > -    // Remove tested attribute to avoid DXE core to dispatch driver
> to
> > > > > > > > memory above 4GB
> > > > > > > > -    Attribue &= ~EFI_RESOURCE_ATTRIBUTE_TESTED;
> > > > > > > > -  }
> > > > > > > > -
> > > > > > > >    BuildResourceDescriptorHob (Type, Attribue,
> > > > > > > > (EFI_PHYSICAL_ADDRESS)Base, Size);
> > > > > > > >    DEBUG ((DEBUG_INFO , "buildhob: base = 0x%lx, size = 0x%lx,
> > > > > > > > type = 0x%x\n", Base, Size, Type));
> > > > > > > >
> > > > > > > > --
> > > > > > > > 2.16.2.windows.1
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > >
> 
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