Lazlo, et al, Please reply below. Leo. > -----Original Message----- > From: Laszlo Ersek [mailto:ler...@redhat.com] > Sent: Wednesday, February 08, 2017 2:39 AM > To: Duran, Leo <leo.du...@amd.com>; edk2-de...@ml01.01.org > Cc: Feng Tian <feng.t...@intel.com>; Singh, Brijesh > <brijesh.si...@amd.com>; Star Zeng <star.z...@intel.com> > Subject: Re: [edk2] [PATCH] MdeModulePkg: Add dynamic PCD > PcdPteMemoryEncryptionAddressOrMask > > On 02/07/17 20:53, Leo Duran wrote: > > From: Brijesh Singh <brijesh.si...@amd.com> > > > > This dynamic PCD holds the address mask for page table entries when > > memory encryption is enabled on AMD processors supporting the Secure > > Encrypted Virtualization (SEV) feature. > > > > Cc: Feng Tian <feng.t...@intel.com> > > Cc: Star Zeng <star.z...@intel.com> > > Cc: Laszlo Ersek <ler...@redhat.com> > > Contributed-under: TianoCore Contribution Agreement 1.0 > > Signed-off-by: Leo Duran <leo.du...@amd.com> > > --- > > MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf | 5 ++++- > > MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c | 18 > ++++++++++-------- > > MdeModulePkg/MdeModulePkg.dec | 8 ++++++++ > > 3 files changed, 22 insertions(+), 9 deletions(-) > > [snip] > > > diff --git a/MdeModulePkg/MdeModulePkg.dec > > b/MdeModulePkg/MdeModulePkg.dec index 273cd7e..207384f 100644 > > --- a/MdeModulePkg/MdeModulePkg.dec > > +++ b/MdeModulePkg/MdeModulePkg.dec > > @@ -6,6 +6,8 @@ > > # Copyright (c) 2007 - 2017, Intel Corporation. All rights > > reserved.<BR> # Copyright (c) 2016, Linaro Ltd. All rights > > reserved.<BR> # (C) Copyright 2016 Hewlett Packard Enterprise > > Development LP<BR> > > +# Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR> # > > # This program and the accompanying materials are licensed and made > > available under # the terms and conditions of the BSD License that > accompanies this distribution. > > # The full text of the license may be found at @@ -1738,5 +1740,11 @@ > > [PcdsDynamic, PcdsDynamicEx] > > # @Prompt If there is any test key used by the platform. > > > > > gEfiMdeModulePkgTokenSpaceGuid.PcdTestKeyUsed|FALSE|BOOLEAN|0x0 > 0030003 > > > > + ## This dynamic PCD holds the address mask for page table entries > > + when memory encryption is # enabled on AMD processors supporting > the Secure Encrypted Virtualization (SEV) feature. > > + # This mask should be applied when creating 1:1 virtual to physical > mapping tables. > > + # > > + > > + > gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrM > ask|0 > > + x0|UINT64|0x00030004 > > + > > [UserExtensions.TianoCore."ExtraFiles"] > > MdeModulePkgExtra.uni > > > > I think this PCD should be added to the following section of the DEC file: > > [PcdsFixedAtBuild, PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx] > > Although OVMF will use the PCD as a dynamic one, I see no reason why the > DEC file should prohibit setting the PCD as a fixed one. > > Looking at other PCDs in the > > [PcdsDynamic, PcdsDynamicEx] > > section, most of those seem to stand for data that are impossible to > determine at build time. Is the new PCD impossible to determine at build > time, for any platform at all? > [Duran, Leo] The PCD should be determined at runtime using CPUID. However, I suppose you may 'know' about your platform at build time.
So to your point, I think it's reasonable to allow fixed, etc. > ... Of course, if it can be proved that any given platform will either > (a) set this new PCD dynamically, or > (b) not even *include* the PCD -- with a dynamic default value -- in > its platform DSC file, > then this patch can work too. > > Thanks > Laszlo _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
