Re: [PATCH V10 0/4] Add Intel TDX support in OvmfPkg/ResetVector

["Yao, Jiewen" <jiewen.yao@intel.com>]

Merged https://github.com/tianocore/edk2/pull/2142

f079e9b450b3896bb00eb7a9fed3a6ec7ed3cd04.. 8b76f235340922a6d293bff05978ba57d3b498e1

> -----Original Message-----
> From: Xu, Min M <min.m.xu@intel.com>
> Sent: Thursday, October 21, 2021 8:18 AM
> To: devel@edk2.groups.io
> Cc: Xu, Min M <min.m.xu@intel.com>; Ard Biesheuvel
> <ardb+tianocore@kernel.org>; Gerd Hoffmann <kraxel@redhat.com>; Justen,
> Jordan L <jordan.l.justen@intel.com>; Brijesh Singh <brijesh.singh@amd.com>;
> Erdem Aktas <erdemaktas@google.com>; James Bottomley
> <jejb@linux.ibm.com>; Yao, Jiewen <jiewen.yao@intel.com>; Tom Lendacky
> <thomas.lendacky@amd.com>
> Subject: [PATCH V10 0/4] Add Intel TDX support in OvmfPkg/ResetVector
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3429
> 
> Intel's Trust Domain Extensions (Intel TDX) refers to an Intel technology
> that extends Virtual Machines Extensions (VMX) and Multi-Key Total Memory
> Encryption (MKTME) with a new kind of virutal machines guest called a
> Trust Domain (TD). A TD is desinged to run in a CPU mode that protects the
> confidentiality of TD memory contents and the TD's CPU state from other
> software, including the hosting Virtual-Machine Monitor (VMM), unless
> explicitly shared by the TD itself.
> 
> The patch-sets to support Intel TDX in OvmfPkg is split into several
> waves. This is wave-1 which adds Intel TDX support in OvmfPkg/ResetVector.
> Note: TDX only works in X64.
> 
> Patch #1: Ovmf uses its own Main.asm to reduce the complexity of Main.asm
> in UefiCpuPkg. This Main.asm is an unmodified copy from
> UefiCpuPkg/ReseteVector/Vtf0 (so no functional change) and the actual
> changes for tdx come as incremental patches.
> 
> Patch #2: WORK_AREA_GUEST_TYPE is cleared in Main.asm instead of in
> WORK_AREA_GUEST_TYPE.
> 
> Patch #3: Introduce IntelTdxMetadata.asm which describes the information
> about the image for VMM use.
> 
> Patch #4: Enable TDX in OvmfPkg/ResetVector for ARCH_X64.
> 
> [TDX]: https://software.intel.com/content/dam/develop/external/us/en/
> documents/tdx-whitepaper-final9-17.pdf
> 
> [TDVF]: https://software.intel.com/content/dam/develop/external/us/en/
> documents/tdx-virtual-firmware-design-guide-rev-1.pdf
> 
> Code is at https://github.com/mxu9/edk2/tree/tdvf_wave1.v10
> 
> v10 changes:
>  - Clear the OVMF_WORK_AREA in both ARCH_IA32 and ARCH_X64.
>  - Update the ReloadFlat32 based on the review comments.
>  - Other minor changes and update some comments.
> 
> v9 changes:
>  - Introduce IntelTdxMetadata.asm in a separate commit.
>  - Use absolute offset for the start of TdxMetadata so that VMM can
>    easily reach to the start of the metadata.
> 
> v8 changes:
>  - Create a separate commit for Main.asm.
>  - Create a separate commit for the clearance of WORK_AREA_GUEST_TYPE.
>  - Fix some inaccurate comments.
> 
> v7 changes:
>  - Refine the offset of TdxMetadata and remove the definition of
>    PcdOvmfImageSizeInKB
>  - Use MOV CR* instead of smsw in ResetVector
>  - Remove the new field (SubType) in
>    CONFIDENTIAL_COMPUTING_WORK_AREA_HEADER.
> 
> v6 changes:
>  - Remove the 5-level paging support. 5-level paging enabling is *NOT*
>    super critical for TDX enabling at this moment. It will be enabled
>    later in a separate patch.
>  - Add a new field (SubType) in
> CONFIDENTIAL_COMPUTING_WORK_AREA_HEADER
>    to record the VM Guest SubType.
>  - In Main16 entry point, after TransitionFromReal16To32BitFlat,
>    WORK_AREA_GUEST_TYPE is cleared to 0. WORK_AREA_GUEST_TYPE was
>    previously cleared in SetCr3ForPageTables64 (see commit ab77b60).
>    This doesn't work after TDX is introduced in Ovmf. It is because all
>    TDX CPUs (BSP and APs) start to run from 0xfffffff0. In previous code
>    WORK_AREA_GUEST_TYPE will be cleared multi-times in TDX guest. So for
>    SEV and Legacy guest it is moved to Main16 entry point (after
>    TransitionFromReal16To32BitFlat). For TDX guest WORK_AREA_GUEST_TYPE
>    is cleared and set in InitTdxWorkarea.
>  - Make the return result of IsTdx be consistent with IsTdxEnabled.
>  - Fix some typo in the code comments.
> 
> v5 changes:
>  - Remove the changes of OVMF_WORK_AREA because Commit ab77b60 covers
>    those changes.
>  - Refine the TDX related changes in PageTables64.asm and
>    Flat32ToFlat64.asm.
>  - Add CheckTdxFeaturesBeforeBuildPagetables to check Non-Tdx, Tdx-BSP or
>    Tdx-APs. This routine is called before building page tables.
> 
> v4 changes:
>  - Refine the PageTables64.asm and Flat32ToFlat64.asm to enable TDX.
>  - Refine SEV_ES_WORK_AREA so that SEV/TDX/Legach guest all can use this
>    memory region. https://edk2.groups.io/g/devel/message/78345 is the
>    discussion.
>  - AmdSev.asm is removed because Brijesh Singh has done it in
>    https://edk2.groups.io/g/devel/message/78241.
> 
> v3 changes:
>  - Refine PageTables64.asm and Flat32ToFlat64.asm based on the review
>    comments in [ReviewComment-1] and [ReviewComment-2].
>  - SEV codes are in AmdSev.asm
>  - TDX codes are in IntelTdx.asm
>  - Main.asm is created in OvmfPkg/ResetVector. The one in
>    UefiCpuPkg/ResetVector/Vtf0 is not used.
>  - Init32.asm/ReloadFlat32.asm in UefiCpuPkg/ResetVector/Vtf0/Ia32 are
>    deleted. They're moved to OvmfPkg/ResetVector/Ia32.
>  - InitTdx.asm is renamed to InteTdx.asm
> 
> v2 changes:
>  - Move InitTdx.asm and ReloadFlat32.asm from UefiCpuPkg/ResetVector/Vtf0
>    to OvmfPkg/ResetVector. Init32.asm is created which is a null stub of
>    32-bit initialization. In Main32 just simply call Init32. It makes
>    the Main.asm in UefiCpuPkg/ResetVector clean and clear.
>  - Init32.asm/InitTdx.asm/ReloadFlat32.asm are created under
>    OvmfPkg/ResetVector/Ia32.
>  - Update some descriptions of the patch-sets.
>  - Update the REF link in cover letter.
>  - Add Ard Biesheuvel in Cc list.
> 
> v1: https://edk2.groups.io/g/devel/message/77675
> 
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Brijesh Singh <brijesh.singh@amd.com>
> Cc: Erdem Aktas <erdemaktas@google.com>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Signed-off-by: Min Xu <min.m.xu@intel.com>
> 
> Min Xu (4):
>   OvmfPkg: Copy Main.asm from UefiCpuPkg to OvmfPkg's ResetVector
>   OvmfPkg: Clear WORK_AREA_GUEST_TYPE in Main.asm
>   OvmfPkg: Add IntelTdxMetadata.asm
>   OvmfPkg: Enable TDX in ResetVector
> 
>  OvmfPkg/OvmfPkg.dec                          |   9 +
>  OvmfPkg/OvmfPkgDefines.fdf.inc               |   9 +
>  OvmfPkg/ResetVector/Ia16/ResetVectorVtf0.asm |  39 ++++
>  OvmfPkg/ResetVector/Ia32/Flat32ToFlat64.asm  |  11 +
>  OvmfPkg/ResetVector/Ia32/IntelTdx.asm        | 222 +++++++++++++++++++
>  OvmfPkg/ResetVector/Ia32/PageTables64.asm    |  22 +-
>  OvmfPkg/ResetVector/Main.asm                 | 121 ++++++++++
>  OvmfPkg/ResetVector/ResetVector.inf          |   9 +
>  OvmfPkg/ResetVector/ResetVector.nasmb        |  28 +++
>  OvmfPkg/ResetVector/X64/IntelTdxMetadata.asm | 115 ++++++++++
>  10 files changed, 581 insertions(+), 4 deletions(-)
>  create mode 100644 OvmfPkg/ResetVector/Ia32/IntelTdx.asm
>  create mode 100644 OvmfPkg/ResetVector/Main.asm
>  create mode 100644 OvmfPkg/ResetVector/X64/IntelTdxMetadata.asm
> 
> --
> 2.29.2.windows.2