Re: [PATCH] MdeModulePkg: Add dynamic PCD PcdPteMemoryEncryptionAddressOrMask

[Laszlo Ersek <lersek@redhat.com>]

On 02/08/17 18:05, Yao, Jiewen wrote:
> HI Leo
> 
> Thanks to clarify that.
> 
>  
> 
> If that is the case, do you think it will be better to limit this PCD to
> X64 only in DEC file. Such as [PcdsDynamic.X64, PcdsDynamicEx.X64]

Not sure if this is the best place to raise the following observation,
but it should do:

please everyone remember that PcdDxeIplSwitchToLongMode is only TRUE if
PEI is 32-bit and DXE is 64-bit. It is FALSE in *two* cases:
- both PEI and DXE are 32-bit, and
- both PEI and DXE are 64-bit.

This doesn't necessarily invalidate anything said thus fair in the
thread, but the following statement from Leo:

    The SEV feature requires 64-bit LongMode, so the
    PcdDxeIplSwitchtoLongMode *must* set to TRUE at build-time

does not follow. The PCD is FALSE in OvmfPkgX64.dsc.

Thanks,
Laszlo

> 
>  
> 
> Thank you
> 
> Yao Jiewen
> 
>  
> 
> *From:*Duran, Leo [mailto:leo.duran@amd.com]
> *Sent:* Wednesday, February 8, 2017 9:00 AM
> *To:* Zeng, Star <star.zeng@intel.com>; edk2-devel@ml01.01.org
> *Cc:* Laszlo Ersek <lersek@redhat.com>; Tian, Feng
> <feng.tian@intel.com>; Singh, Brijesh <brijesh.singh@amd.com>; Yao,
> Jiewen <jiewen.yao@intel.com>
> *Subject:* RE: [edk2] [PATCH] MdeModulePkg: Add dynamic PCD
> PcdPteMemoryEncryptionAddressOrMask
> 
>  
> 
> Pease see reply below.
> Leo
> 
>> -----Original Message-----
>> From: Zeng, Star [mailto:star.zeng@intel.com]
>> Sent: Tuesday, February 07, 2017 8:27 PM
>> To: Duran, Leo <leo.duran@amd.com <mailto:leo.duran@amd.com>>; edk2-devel@ml01.01.org
> <mailto:edk2-devel@ml01.01.org>
>> Cc: Laszlo Ersek <lersek@redhat.com
> <mailto:lersek@redhat.com>>; Tian, Feng <feng.tian@intel.com
> <mailto:feng.tian@intel.com>>;
>> Singh, Brijesh <brijesh.singh@amd.com
> <mailto:brijesh.singh@amd.com>>; Zeng, Star <star.zeng@intel.com
> <mailto:star.zeng@intel.com>>;
>> Yao, Jiewen <jiewen.yao@intel.com <mailto:jiewen.yao@intel.com>>
>> Subject: RE: [edk2] [PATCH] MdeModulePkg: Add dynamic PCD
>> PcdPteMemoryEncryptionAddressOrMask
>> 
>> Does Create4GPageTablesIa32Pae() also need to be updated?
>> 
>> Thanks,
>> Star
> [Duran, Leo] 
> Hi Star,
> No, I do not think Create4GPageTablesIa32Pae() is in the execution path.
> 
> The SEV feature requires 64-bit LongMode, so the PcdDxeIplSwitchtoLongMode *must* set to TRUE at build-time,
> in which case Create4GPageTablesIa32Pae() would *not* be called by HandOffToDxeCore().
> 
>> -----Original Message-----
>> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of
>> Leo Duran
>> Sent: Wednesday, February 8, 2017 3:54 AM
>> To: edk2-devel@ml01.01.org <mailto:edk2-devel@ml01.01.org>
>> Cc: Laszlo Ersek <lersek@redhat.com
> <mailto:lersek@redhat.com>>; Tian, Feng <feng.tian@intel.com
> <mailto:feng.tian@intel.com>>;
>> Brijesh Singh <brijesh.singh@amd.com
> <mailto:brijesh.singh@amd.com>>; Zeng, Star <star.zeng@intel.com
> <mailto:star.zeng@intel.com>>;
>> Leo Duran <leo.duran@amd.com <mailto:leo.duran@amd.com>>
>> Subject: [edk2] [PATCH] MdeModulePkg: Add dynamic PCD
>> PcdPteMemoryEncryptionAddressOrMask
>> 
>> From: Brijesh Singh <brijesh.singh@amd.com <mailto:brijesh.singh@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.tian@intel.com <mailto:feng.tian@intel.com>>
>> Cc: Star Zeng <star.zeng@intel.com <mailto:star.zeng@intel.com>>
>> Cc: Laszlo Ersek <lersek@redhat.com <mailto:lersek@redhat.com>>
>> Contributed-under: TianoCore Contribution Agreement 1.0
>> Signed-off-by: Leo Duran <leo.duran@amd.com <mailto:leo.duran@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(-)
>> 
>> diff --git a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf
>> b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf
>> index 2bc41be..d62bd9b 100644
>> --- a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf
>> +++ b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf
>> @@ -6,6 +6,8 @@
>>  #  needed to run the DXE Foundation.
>>  #
>>  #  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<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  #  which
>> accompanies this distribution.  The full text of the license may be found at
>> @@ -111,7 +113,8 @@ [FeaturePcd]
>>    gEfiMdeModulePkgTokenSpaceGuid.PcdDxeIplSupportUefiDecompress ##
>> CONSUMES
>> 
>>  [Pcd.IA32,Pcd.X64]
>> -  gEfiMdeModulePkgTokenSpaceGuid.PcdUse1GPageTable              ##
>> SOMETIMES_CONSUMES
>> +  gEfiMdeModulePkgTokenSpaceGuid.PcdUse1GPageTable                      ##
>> SOMETIMES_CONSUMES
>> +
>> gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrM
>> ask    ## CONSUMES
>> 
>>  [Pcd.IA32,Pcd.X64,Pcd.ARM,Pcd.AARCH64]
>>    gEfiMdeModulePkgTokenSpaceGuid.PcdSetNxForStack               ##
>> SOMETIMES_CONSUMES
>> diff --git a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c
>> b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c
>> index 790f6ab..2c52389 100644
>> --- a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c
>> +++ b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c
>> @@ -16,6 +16,8 @@
>>      3) IA-32 Intel(R) Architecture Software Developer's Manual Volume
>> 3:System Programmer's Guide, Intel
>> 
>>  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<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  which
>> accompanies this distribution.  The full text of the license may be found at
>> @@ -71,14 +73,14 @@ Split2MPageTo4K (
>>    //
>>    // Fill in 2M page entry.
>>    //
>> -  *PageEntry2M = (UINT64) (UINTN) PageTableEntry | IA32_PG_P |
>> IA32_PG_RW;
>> +  *PageEntry2M = (UINT64) (UINTN) PageTableEntry | PcdGet64
>> + (PcdPteMemoryEncryptionAddressOrMask) | IA32_PG_P | IA32_PG_RW;
>> 
>>    PhysicalAddress4K = PhysicalAddress;
>>    for (IndexOfPageTableEntries = 0; IndexOfPageTableEntries < 512;
>> IndexOfPageTableEntries++, PageTableEntry++, PhysicalAddress4K +=
>> SIZE_4KB) {
>>      //
>>      // Fill in the Page Table entries
>>      //
>> -    PageTableEntry->Uint64 = (UINT64) PhysicalAddress4K;
>> +    PageTableEntry->Uint64 = (UINT64) PhysicalAddress4K | PcdGet64
>> + (PcdPteMemoryEncryptionAddressOrMask);
>>      PageTableEntry->Bits.ReadWrite = 1;
>>      PageTableEntry->Bits.Present = 1;
>>      if ((PhysicalAddress4K >= StackBase) && (PhysicalAddress4K < StackBase +
>> StackSize)) { @@ -116,7 +118,7 @@ Split1GPageTo2M (
>>    //
>>    // Fill in 1G page entry.
>>    //
>> -  *PageEntry1G = (UINT64) (UINTN) PageDirectoryEntry | IA32_PG_P |
>> IA32_PG_RW;
>> +  *PageEntry1G = (UINT64) (UINTN) PageDirectoryEntry | PcdGet64
>> + (PcdPteMemoryEncryptionAddressOrMask) | IA32_PG_P | IA32_PG_RW;
>> 
>>    PhysicalAddress2M = PhysicalAddress;
>>    for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512;
>> IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PhysicalAddress2M
>> += SIZE_2MB) { @@ -129,7 +131,7 @@ Split1GPageTo2M (
>>        //
>>        // Fill in the Page Directory entries
>>        //
>> -      PageDirectoryEntry->Uint64 = (UINT64) PhysicalAddress2M;
>> +      PageDirectoryEntry->Uint64 = (UINT64) PhysicalAddress2M |
>> + PcdGet64 (PcdPteMemoryEncryptionAddressOrMask);
>>        PageDirectoryEntry->Bits.ReadWrite = 1;
>>        PageDirectoryEntry->Bits.Present = 1;
>>        PageDirectoryEntry->Bits.MustBe1 = 1; @@ -248,7 +250,7 @@
>> CreateIdentityMappingPageTables (
>>      //
>>      // Make a PML4 Entry
>>      //
>> -    PageMapLevel4Entry->Uint64 =
>> (UINT64)(UINTN)PageDirectoryPointerEntry;
>> +    PageMapLevel4Entry->Uint64 =
>> + (UINT64)(UINTN)PageDirectoryPointerEntry | PcdGet64
>> + (PcdPteMemoryEncryptionAddressOrMask);
>>      PageMapLevel4Entry->Bits.ReadWrite = 1;
>>      PageMapLevel4Entry->Bits.Present = 1;
>> 
>> @@ -262,7 +264,7 @@ CreateIdentityMappingPageTables (
>>            //
>>            // Fill in the Page Directory entries
>>            //
>> -          PageDirectory1GEntry->Uint64 = (UINT64)PageAddress;
>> +          PageDirectory1GEntry->Uint64 = (UINT64)PageAddress | PcdGet64
>> + (PcdPteMemoryEncryptionAddressOrMask);
>>            PageDirectory1GEntry->Bits.ReadWrite = 1;
>>            PageDirectory1GEntry->Bits.Present = 1;
>>            PageDirectory1GEntry->Bits.MustBe1 = 1; @@ -280,7 +282,7 @@
>> CreateIdentityMappingPageTables (
>>          //
>>          // Fill in a Page Directory Pointer Entries
>>          //
>> -        PageDirectoryPointerEntry->Uint64 =
>> (UINT64)(UINTN)PageDirectoryEntry;
>> +        PageDirectoryPointerEntry->Uint64 =
>> + (UINT64)(UINTN)PageDirectoryEntry | PcdGet64
>> + (PcdPteMemoryEncryptionAddressOrMask);
>>          PageDirectoryPointerEntry->Bits.ReadWrite = 1;
>>          PageDirectoryPointerEntry->Bits.Present = 1;
>> 
>> @@ -294,7 +296,7 @@ CreateIdentityMappingPageTables (
>>              //
>>              // Fill in the Page Directory entries
>>              //
>> -            PageDirectoryEntry->Uint64 = (UINT64)PageAddress;
>> +            PageDirectoryEntry->Uint64 = (UINT64)PageAddress | PcdGet64
>> + (PcdPteMemoryEncryptionAddressOrMask);
>>              PageDirectoryEntry->Bits.ReadWrite = 1;
>>              PageDirectoryEntry->Bits.Present = 1;
>>              PageDirectoryEntry->Bits.MustBe1 = 1; 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|0x0
>> + |UINT64|0x00030004
>> +
>>  [UserExtensions.TianoCore."ExtraFiles"]
>>    MdeModulePkgExtra.uni
>> --
>> 1.9.1
>> 
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