Re: [edk2-devel] [PATCH v14 00/46] SEV-ES guest support

["Lendacky, Thomas" <thomas.lendacky@amd.com>]

Hi Liming,

Thank you, the updated series can be found here:

  https://github.com/AMDESE/ovmf/tree/sev-es-v23

Thanks,
Tom

On 8/12/20 10:28 AM, Gao, Liming wrote:
> Tom:
>   I understand your point. Now, I run this script on Windows OS. I don't try it on Linux agent. You can upload new patch set to your fork branch. I will verify it and let your know the result. 
> 
>   And, I plan to merge ECC checker this week. So, more patches can be verified. 
> 
> Thanks
> Liming
>> -----Original Message-----
>> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Lendacky, Thomas
>> Sent: Wednesday, August 12, 2020 11:18 PM
>> To: Gao, Liming <liming.gao@intel.com>; devel@edk2.groups.io; Laszlo Ersek <lersek@redhat.com>
>> Cc: Brijesh Singh <brijesh.singh@amd.com>; Ard Biesheuvel <ard.biesheuvel@arm.com>; Dong, Eric <eric.dong@intel.com>; Justen,
>> Jordan L <jordan.l.justen@intel.com>; Kinney, Michael D <michael.d.kinney@intel.com>; Ni, Ray <ray.ni@intel.com>; Andrew Fish
>> <afish@apple.com>; Anthony Perard <anthony.perard@citrix.com>; You, Benjamin <benjamin.you@intel.com>; Bi, Dandan
>> <dandan.bi@intel.com>; Dong, Guo <guo.dong@intel.com>; Wu, Hao A <hao.a.wu@intel.com>; Wang, Jian J <jian.j.wang@intel.com>;
>> Julien Grall <julien@xen.org>; Leif Lindholm <leif@nuviainc.com>; Ma, Maurice <maurice.ma@intel.com>
>> Subject: Re: [edk2-devel] [PATCH v14 00/46] SEV-ES guest support
>>
>> Hi Liming,
>>
>> So I'm not sure what the next step is then... Since the ECC checker isn't
>> merged yet, are you saying that I should submit the series again with the
>> changes and that you won't be running the stand-alone tool again? Or will
>> you run the tool again and submit more issues to resolve if the tool finds
>> any? If it's the latter, I would really like to be able to run this tool
>> stand-alone, as you have done, so that I don't have to keep re-submitting
>> the series (because it looks like the tool doesn't catch everything and
>> fixing one thing may then expose another).
>>
>> Thanks,
>> Tom
>>
>> On 8/12/20 9:34 AM, Gao, Liming wrote:
>>> Tom:
>>>
>>> -----Original Message-----
>>> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Lendacky, Thomas
>>> Sent: 2020年8月12日 0:18
>>> To: Laszlo Ersek <lersek@redhat.com>; Gao, Liming <liming.gao@intel.com>; devel@edk2.groups.io
>>> Cc: Brijesh Singh <brijesh.singh@amd.com>; Ard Biesheuvel <ard.biesheuvel@arm.com>; Dong, Eric <eric.dong@intel.com>; Justen,
>> Jordan L <jordan.l.justen@intel.com>; Kinney, Michael D <michael.d.kinney@intel.com>; Ni, Ray <ray.ni@intel.com>; Andrew Fish
>> <afish@apple.com>; Anthony Perard <anthony.perard@citrix.com>; You, Benjamin <benjamin.you@intel.com>; Bi, Dandan
>> <dandan.bi@intel.com>; Dong, Guo <guo.dong@intel.com>; Wu, Hao A <hao.a.wu@intel.com>; Wang, Jian J <jian.j.wang@intel.com>;
>> Julien Grall <julien@xen.org>; Leif Lindholm <leif@nuviainc.com>; Ma, Maurice <maurice.ma@intel.com>
>>> Subject: Re: [edk2-devel] [PATCH v14 00/46] SEV-ES guest support
>>>
>>> On 8/11/20 9:49 AM, Laszlo Ersek wrote:
>>>> On 08/11/20 03:12, Gao, Liming wrote:
>>>>> Tom:
>>>>>   I run ECC plugin
>> (https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fedk2.groups.io%2Fg%2Fdevel%2Fmessage%2F63271&amp;dat
>> a=02%7C01%7Cthomas.lendacky%40amd.com%7C4285f946d86342630a4708d83ecccf27%7C3dd8961fe4884e608e11a82d994e183d%7C
>> 0%7C0%7C637328396655798086&amp;sdata=27ydFZdocl9RV7MbrLRKw0L2GiOGtWLlpsuaw9wj2fo%3D&amp;reserved=0) in my local
>> machine. It reports below issues. Can you help update the patches to fix them?
>>>>>   I use the standalone EccCheck from
>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fshenglei10%2Fedk2%2Ftree%2Fecc_script&amp
>> ;data=02%7C01%7Cthomas.lendacky%40amd.com%7C4285f946d86342630a4708d83ecccf27%7C3dd8961fe4884e608e11a82d994e183d
>> %7C0%7C0%7C637328396655798086&amp;sdata=b8VUf6uNw%2FzNBZCKU0IUUakDLJPmVsK4ghJirmQwCwY%3D&amp;reserved=0.
>>>>>
>>>>> EFI coding style error
>>>>>   *Error code: 8005
>>>>>   *Variable name does not follow the rules: 1. First character should be upper case 2. Must contain lower case characters 3. No
>> white space characters 4. Global variable name must start with a 'g'
>>>>>   *file: D:\AllPkg\edk2\OvmfPkg\Sec\SecMain.c
>>>>>   *Line number: 867
>>>>>   *The variable name [*Ds] does not follow the rules
>>>>
>>>> I don't understand this report; with this series applied, line 867 is
>>>> the following:
>>>>
>>>>     867     UINT8  *Src, *Dst;
>>>>
>>>> coming from patch v14 37/46, "OvmfPkg/Sec: Add #VC exception handling
>>>> for Sec phase".
>>>>
>>>> Perhaps ECC is confused because we have two declarations on the same
>>>> line; I'm not sure.
>>>>
>>>> In general I too like to keep declarations on separate lines, but
>>>> there are exceptions. Declaring *Src and *Dst on the same line is
>>>> pretty reasonable, and trivial.
>>>>
>>>> I think it's time for us to put the ECC exception list to use, under
>>>> OvmfPkg.
>>>>
>>>> Tom, please try to reproduce this error locally, and then modify
>>>> "OvmfPkg/OvmfPkg.ci.yaml", adding an exception under the EccCheck block.
>>>>
>>>> ... Oh wait, we haven't even merged Shenglei's series for that! The
>>>> latest posting is:
>>>>
>>>>   [edk2-devel] [PATCH v9 00/16]
>>>>   Add a plugin to check Ecc issues for edk2 on open ci
>>>>
>>>> and it's still under review.
>>>>
>>>> Indeed, Liming says above that he used the "standalone EccCheck".
>>>>
>>>> OK. In this case, I state that some of these ECC reports for OvmfPkg
>>>> should be waived.
>>>>
>>>> I'm in general of the opinion that ECC is too strict, and package
>>>> maintainers should have power to selectively enforce or override ECC
>>>> reports. That's why I agreed to the ECC CI plugin in the first place
>>>> -- becase we have exception lists that are controllable under specific
>>>> package directories (in the *.ci.yaml files).
>>>>
>>>> In the present case, running the standalone ECC check has worse
>>>> granularity than the upcoming ECC CI plugin. So, because I can't ask
>>>> Tom to add a new exception to "OvmfPkg/OvmfPkg.ci.yaml" right now
>>>> (before we merge this series), I'm replacing that with a waiver in this email.
>>>>
>>>> Of course, if maintainers of other packages want the ECC reports
>>>> issued under their packages addressed, that's their call. I can only
>>>> waive ECC reports under OvmfPkg.
>>>>
>>>>> EFI coding style error
>>>>>   *Error code: 9003
>>>>>   *The first line of text in a comment block should be a brief description of the element being documented and the brief
>> description must end with a period.
>>>>>   *file: D:\AllPkg\edk2\OvmfPkg\Library\BaseMemEncryptSevLib\MemEncryptSevLibInternal.c
>>>>>   *Line number: 72
>>>>>   *Comment description should end with period '.'
>>>>
>>>> Disagree; sometimes people use well-formed full English sentences,
>>>> sometimes only thought fragments.
>>>>
>>>>> EFI coding style error
>>>>>   *Error code: 3002
>>>>>   *Non-Boolean comparisons should use a compare operator (==, !=, >, < >=, <=)
>>>>>   *file: D:\AllPkg\edk2\OvmfPkg\Library\VmgExitLib\VmgExitVcHandler.c
>>>>>   *Line number: 1280
>>>>>   *Predicate Expression: OpCount
>>>>
>>>> On the other hand, this report *is* worth fixing.
>>>>
>>>>    1280     while (OpCount) {
>>>>
>>>> I've myself asked Tom for observing this rule at several locations,
>>>> but we both missed the one reported above. It comes from patch #14
>>>> ("OvmfPkg/VmgExitLib: Support string IO for IOIO_PROT NAE events").
>>>>
>>>>> EFI coding style error
>>>>>   *Error code: 5007
>>>>>   *There should be no initialization of a variable as part of its declaration
>>>>>   *file: D:\AllPkg\edk2\OvmfPkg\Library\VmgExitLib\VmgExitVcHandler.c
>>>>>   *Line number: 845
>>>>>   *Variable Name: Data
>>>>
>>>> Agree this should be fixed; I should have noticed it during review. My
>>>> apologies.
>>>>
>>>>     845       UINT8 *Data = (UINT8 *) Ghcb->SharedBuffer;
>>>>
>>>> Comes from patch #17 ("OvmfPkg/VmgExitLib: Add support for NPF NAE
>>>> events (MMIO)").
>>>>
>>>>> EFI coding style error
>>>>>   *Error code: 5007
>>>>>   *There should be no initialization of a variable as part of its declaration
>>>>>   *file: D:\AllPkg\edk2\OvmfPkg\Library\VmgExitLib\VmgExitVcHandler.c
>>>>>   *Line number: 849
>>>>>   *Variable Name: Data
>>>>
>>>> Yes, this should be fixed too:
>>>>
>>>>     849       UINT16 *Data = (UINT16 *) Ghcb->SharedBuffer;
>>>>
>>>> Again, I should have noticed it; I'm sorry.
>>>>
>>>> It comes from patch #17 ("OvmfPkg/VmgExitLib: Add support for NPF NAE
>>>> events (MMIO)") again.
>>>>
>>>> Tom: given that a new iteration seems justified after all (I'm really
>>>> sorry about that -- with Shenglei's series hopefully soon merged, such
>>>> issues will be reported earlier!), if you'd like, you could address
>>>> the two ECC reports too that I said were too strict and should be ignored.
>>>> (That means breaking the "*Dst" declaration to a new line, and adding
>>>> a period to the comment.) Up to you; I certainly don't insist on those.
>>>
>>> No worries, easy enough to do if I'm already updating the others.
>>>
>>> I would like to be able to run this tool on my system, though, to see if anything else gets flagged after fixing the above mentioned
>> issues. But the tool fails for me as I described in another post. The reason I say that is, for example, the issue about the comment
>> description ending with a period was actually in multiple spots of the commit, even though the tool only flagged one. I'd hate to
>> think I've fixed everything only to have the tool find more issues after I've submitted another series, all because I couldn't run the
>> tool.
>>>
>>> Thanks,
>>> Tom
>>>
>>> [Liming] ECC checker will be merged in open CI to check the patch and report the issues. Then, you don't need to run it in your local
>> machine. I use this patch set as test case to verify ECC checker functionality. And, it reports those issues. I think they are valuable for
>> this patch set, so I raise them. Sorry for the late notice.
>>>
>>> Thanks
>>> Liming
>>>>
>>>> Thanks!
>>>> Laszlo
>>>>
>>>>>
>>>>> Thanks
>>>>> Liming
>>>>> -----Original Message-----
>>>>> From: Laszlo Ersek <lersek@redhat.com>
>>>>> Sent: 2020年8月11日 3:36
>>>>> To: devel@edk2.groups.io; thomas.lendacky@amd.com
>>>>> Cc: Brijesh Singh <brijesh.singh@amd.com>; Ard Biesheuvel
>>>>> <ard.biesheuvel@arm.com>; Dong, Eric <eric.dong@intel.com>; Justen,
>>>>> Jordan L <jordan.l.justen@intel.com>; Gao, Liming
>>>>> <liming.gao@intel.com>; Kinney, Michael D
>>>>> <michael.d.kinney@intel.com>; Ni, Ray <ray.ni@intel.com>; Andrew Fish
>>>>> <afish@apple.com>; Anthony Perard <anthony.perard@citrix.com>; You,
>>>>> Benjamin <benjamin.you@intel.com>; Bi, Dandan <dandan.bi@intel.com>;
>>>>> Dong, Guo <guo.dong@intel.com>; Wu, Hao A <hao.a.wu@intel.com>; Wang,
>>>>> Jian J <jian.j.wang@intel.com>; Julien Grall <julien@xen.org>; Leif
>>>>> Lindholm <leif@nuviainc.com>; Ma, Maurice <maurice.ma@intel.com>
>>>>> Subject: Re: [edk2-devel] [PATCH v14 00/46] SEV-ES guest support
>>>>>
>>>>> On 08/07/20 21:38, Lendacky, Thomas wrote:
>>>>>> From: Tom Lendacky <thomas.lendacky@amd.com>
>>>>>>
>>>>>> This patch series provides support for running EDK2/OVMF under SEV-ES.
>>>>>>
>>>>>> Secure Encrypted Virtualization - Encrypted State (SEV-ES) expands
>>>>>> on the SEV support to protect the guest register state from the
>>>>>> hypervisor. See
>>>>>> "AMD64 Architecture Programmer's Manual Volume 2: System
>>>>>> Programming", section "15.35 Encrypted State (SEV-ES)" [1].
>>>>>>
>>>>>> In order to allow a hypervisor to perform functions on behalf of a
>>>>>> guest, there is architectural support for notifying a guest's
>>>>>> operating system when certain types of VMEXITs are about to occur.
>>>>>> This allows the guest to selectively share information with the
>>>>>> hypervisor to satisfy the requested function. The notification is
>>>>>> performed using a new exception, the VMM Communication exception
>>>>>> (#VC). The information is shared through the Guest-Hypervisor Communication Block (GHCB) using the VMGEXIT instruction.
>>>>>> The GHCB format and the protocol for using it is documented in
>>>>>> "SEV-ES Guest-Hypervisor Communication Block Standardization" [2].
>>>>>>
>>>>>> The main areas of the EDK2 code that are updated to support SEV-ES
>>>>>> are around the exception handling support and the AP boot support.
>>>>>>
>>>>>> Exception support is required starting in Sec, continuing through
>>>>>> Pei and into Dxe in order to handle #VC exceptions that are generated.
>>>>>> Each AP requires it's own GHCB page as well as a page to hold values
>>>>>> specific to that AP.
>>>>>>
>>>>>> AP booting poses some interesting challenges. The INIT-SIPI-SIPI
>>>>>> sequence is typically used to boot the APs. However, the hypervisor
>>>>>> is not allowed to update the guest registers. The GHCB document [2]
>>>>>> talks about how SMP booting under SEV-ES is performed.
>>>>>>
>>>>>> Since the GHCB page must be a shared (unencrypted) page, the
>>>>>> processor must be running in long mode in order for the guest and
>>>>>> hypervisor to communicate with each other. As a result, SEV-ES is
>>>>>> only supported under the X64 architecture.
>>>>>>
>>>>>> This series adds a new library requirement for the VmgExitLib
>>>>>> library against the UefiCpuPkg CpuExceptionHandlerLib library and
>>>>>> the UefiCpuPkg MpInitLib library. The edk2-platforms repo requires
>>>>>> updates/patches to add the new library requirement. To accomodate
>>>>>> that, this series could be split between:
>>>>>>
>>>>>> patch number 10:
>>>>>>   UefiPayloadPkg: Prepare UefiPayloadPkg to use the VmgExitLib
>>>>>> library
>>>>>>
>>>>>> and patch number 11:
>>>>>>   UefiCpuPkg/CpuExceptionHandler: Add base support for the #VC
>>>>>> exception
>>>>>>
>>>>>> The updates to edk2-platforms can be applied at the split.
>>>>>>
>>>>>> [1]
>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fww
>>>>>> w.amd.com%2Fsystem%2Ffiles%2FTechDocs%2F24593.pdf&amp;data=02%7C01%7
>>>>>> Cthomas.lendacky%40amd.com%7C9c0fb2b16af248090fdb08d83e05c821%7C3dd8
>>>>>> 961fe4884e608e11a82d994e183d%7C0%7C0%7C637327542159394484&amp;sdata=
>>>>>> zusPC5xFZWfLxt6T5Psxb1%2Fw4mrVWnkrrECkuKSsxLk%3D&amp;reserved=0
>>>>>> [2]
>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fde
>>>>>> veloper.amd.com%2Fwp-content%2Fresources%2F56421.pdf&amp;data=02%7C0
>>>>>> 1%7Cthomas.lendacky%40amd.com%7C9c0fb2b16af248090fdb08d83e05c821%7C3
>>>>>> dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637327542159394484&amp;sda
>>>>>> ta=yk7o8h1lajI449tZfXGbPumnkvRjswKp1FRmSUdewh4%3D&amp;reserved=0
>>>>>>
>>>>>> ---
>>>>>>
>>>>>> These patches are based on commit:
>>>>>> 9565ab67c209 ("ShellPkg: smbiosview - Change some type 17 field
>>>>>> values
>>>>>> format")
>>>>>>
>>>>>> A version of the tree can be found at:
>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgi
>>>>>> thub.com%2FAMDESE%2Fovmf%2Ftree%2Fsev-es-v22&amp;data=02%7C01%7Cthom
>>>>>> as.lendacky%40amd.com%7C9c0fb2b16af248090fdb08d83e05c821%7C3dd8961fe
>>>>>> 4884e608e11a82d994e183d%7C0%7C0%7C637327542159404476&amp;sdata=6b9Eq
>>>>>> EVAy1VK38oMSuAPJhOourJpPXUnRIgMcSWRMQc%3D&amp;reserved=0
>>>>>>
>>>>>> Cc: Andrew Fish <afish@apple.com>
>>>>>> Cc: Anthony Perard <anthony.perard@citrix.com>
>>>>>> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
>>>>>> Cc: Benjamin You <benjamin.you@intel.com>
>>>>>> Cc: Dandan Bi <dandan.bi@intel.com>
>>>>>> Cc: Eric Dong <eric.dong@intel.com>
>>>>>> Cc: Guo Dong <guo.dong@intel.com>
>>>>>> Cc: Hao A Wu <hao.a.wu@intel.com>
>>>>>> Cc: Jian J Wang <jian.j.wang@intel.com>
>>>>>> Cc: Jordan Justen <jordan.l.justen@intel.com>
>>>>>> Cc: Julien Grall <julien@xen.org>
>>>>>> Cc: Laszlo Ersek <lersek@redhat.com>
>>>>>> Cc: Leif Lindholm <leif@nuviainc.com>
>>>>>> Cc: Liming Gao <liming.gao@intel.com>
>>>>>> Cc: Maurice Ma <maurice.ma@intel.com>
>>>>>> Cc: Michael D Kinney <michael.d.kinney@intel.com>
>>>>>> Cc: Ray Ni <ray.ni@intel.com>
>>>>>>
>>>>>> Changes since v13:
>>>>>> - Fixup the AsmRelocateApLoop() call site so IA32 successfully boots APs.
>>>>>>   Do this by appending the three new parameters without altering the
>>>>>>   original parameter passing order.
>>>>>> - Minor updates to description text and help text to expand the GHCB
>>>>>>   acronym.
>>>>>>
>>>>>> Changes since v12:
>>>>>> - Change IA32 VMGEXIT .nasm file to issue an int 3. Depending on the
>>>>>>   version of NASM, the "BITS 64" trick to get NASM to recognize the
>>>>>>   VMMCALL instruction (VMGEXIT is a REP VMMCALL) caused an error. Since
>>>>>>   SEV-ES is X64 only, VMGEXIT should never be called in IA32.
>>>>>>
>>>>>> Changes since v11:
>>>>>> - Make the XGETBV and VMGEXIT .nasm files buildable for all environments
>>>>>>   and remove the updates that add these instructions to GccInline.c
>>>>>>
>>>>>> Changes since v10:
>>>>>> - Fix conflicts around GccInline.c file after moving to latest
>>>>>> commit
>>>>>> - Fix conflicts with OVMF PCD values after moving to latest commit
>>>>>>
>>>>>> Changes since v9:
>>>>>> - Fixed bit field declarations in the GHCB structure to use UINT32
>>>>>>   and not UINT64.
>>>>>> - Fixed a warning produced by VS2019 in the instruction parsing code
>>>>>>   by expliciting casting a bit shift to an INT64.
>>>>>> - Sorted section entries in the OVMF VmgExitLib INF file.
>>>>>> - Moved the new Maintainers.txt entry so entries remain sorted.
>>>>>> - Documentation style fixes for return values.
>>>>>> - Miscellaneous code style fixes.
>>>>>>
>>>>>> Changes since v8:
>>>>>> - Move IOIO exit info definitions into Ghcb.h file
>>>>>>   - Add a macro for calculating IO instruction bytes
>>>>>> (IOIO_DATA_BYTES)
>>>>>> - Exception handler support for debug registers
>>>>>>   - Moved the DRx register saving changes into the UefiCpuPkg patch for
>>>>>>     base #VC support in CpuExceptionHandlerLib.
>>>>>> - OvmfPkg VmgExitLib
>>>>>>   - Remove the .uni file
>>>>>>   - Update .inf file:
>>>>>>     - New file location for VmgExitVcHandler.c
>>>>>>     - Add additional Packages and LibraryClasses
>>>>>> - Introduce a header file to hold the #VC instruction parsing related
>>>>>>   definitions
>>>>>>   - Include additional #defines for instruction decoding to replace
>>>>>>     hard coded values for things like instruction prefixes and escapes.
>>>>>> - Replace hardcoded CPUID values with values from existing header files
>>>>>>   and use existing CR4 definition for accessing CR4 data.
>>>>>> - Change the type used for obtaining data addresses in the instruction
>>>>>>   parsing
>>>>>>   - Switch from INTN to UINT64 and use compiler conversions and casting
>>>>>>     to perform the correct address calculation
>>>>>> - ResetVector code:
>>>>>>   - Revert some inadvertant changes introduced in v7 for reserving the
>>>>>>     SEV-ES work area memory and for checking the status of SEV-ES.
>>>>>> - AP Booting
>>>>>>   - Provide support for non-broadcast INIT-SIPI-SIPI AP boot (minimize
>>>>>>     code duplication by creating a function to set the AP jump table
>>>>>>     vector address).
>>>>>> - Fix file/directory entry in maintainer changes.
>>>>>> - Various coding style fixes
>>>>>>   - Commenting, if statements, etc.
>>>>>> - Various documentation style fixes
>>>>>>
>>>>>> Changes since v7:
>>>>>> - Reserve the SEV-ES workarea when S3 is enabled
>>>>>> - Fix warnings issued by the Visual Studio compiler
>>>>>> - Create a NULL VmgExitLib instance that is used for VMGEXIT
>>>>>>   related operations as well as #VC handling. Then create the full
>>>>>>   VmgExitLib support only in OvmfPkg - where it will be used. This
>>>>>>   removes a bunch of implementation code from platforms that will
>>>>>>   not be using the functionality.
>>>>>> - Remove single use interfaces from the VmgExitLib (VmgMmioWrite
>>>>>>   and VmgSetApJumpTable)
>>>>>>
>>>>>> Changes since v6:
>>>>>> - Add function comments to all functions, including local functions
>>>>>> - Add function parameter direction to all functions (in/out)
>>>>>> - Add support for MMIO MOVZX/MOVSX instructions
>>>>>> - Ensure the per-CPU variable page remains encrypted
>>>>>> - Coding-style fixes as identified by Ecc
>>>>>>
>>>>>> Changes since v5:
>>>>>> - Remove extraneous VmgExitLib usage
>>>>>> - Miscellaneous changes to address feedback (coding style, etc.)
>>>>>>
>>>>>> Changes since v4:
>>>>>> - Move the SEV-ES protocol negotiation out of the SEC exception handler
>>>>>>   and into the SecMain.c file. As a result:
>>>>>>   - Move the SecGhcb related PCDs out of UefiCpuPkg and into OvmfPkg
>>>>>>   - Combine SecAMDSevVcHandler.c and PeiDxeAMDSevVcHandler.c into a
>>>>>>     single AMDSevVcHandler.c
>>>>>> - Consolidate VmgExitLib usage into common LibraryClasses sections
>>>>>> - Add documentation comments to the VmgExitLib functions
>>>>>>
>>>>>> Changes since v3:
>>>>>> - Remove the need for the MP library finalization routine. The AP
>>>>>>   jump table address will be held by the hypervisor rather than
>>>>>>   communicated via the GHCB MSR. This removes some fragility around
>>>>>>   the UEFI to OS transition.
>>>>>> - Rename the SEV-ES RIP reset area to SEV-ES workarea and use it to
>>>>>>   communicate the SEV-ES status, so that SEC CPU exception handling is
>>>>>>   only established for an SEV-ES guest.
>>>>>> - Fix SMM build breakageAdd around QemuFlashPtrWrite().
>>>>>> - Fix SMM build breakage by adding VC exception support the SMM CPU
>>>>>>   exception handling.
>>>>>> - Add memory fencing around the invocation of AsmVmgExit().
>>>>>> - Clarify comments around the SEV-ES AP reset RIP values and usage.
>>>>>> - Move some PCD definitions from MdeModulePkg to UefiCpuPkg.
>>>>>> - Remove the 16-bit code selector definition from MdeModulePkg
>>>>>>
>>>>>> Changes since v2:
>>>>>> - Added a way to locate the SEV-ES fixed AP RIP address for starting
>>>>>>   AP's to avoid updating the actual flash image (build time location
>>>>>>   that is identified with a GUID value).
>>>>>> - Create a VmgExit library to replace static inline functions.
>>>>>> - Move some PCDs to the appropriate packages
>>>>>> - Add support for writing to QEMU flash under SEV-ES
>>>>>> - Add additional MMIO opcode support
>>>>>> - Cleaned up the GHCB MSR CPUID protocol support
>>>>>>
>>>>>> Changes since v1:
>>>>>> - Patches reworked to be more specific to the component/area being updated
>>>>>>   and order of definition/usage
>>>>>> - Created a library for VMGEXIT-related functions to replace use of inline
>>>>>>   functions
>>>>>> - Allocation method for GDT changed from AllocatePool to
>>>>>> AllocatePages
>>>>>> - Early caching only enabled for SEV-ES guests
>>>>>> - Ensure AP loop mode set to halt loop mode for SEV-ES guests
>>>>>> - Reserved SEC GHCB-related memory areas when S3 is enabled
>>>>>>
>>>>>> Tom Lendacky (46):
>>>>>>   MdeModulePkg: Create PCDs to be used in support of SEV-ES
>>>>>>   UefiCpuPkg: Create PCD to be used in support of SEV-ES
>>>>>>   MdePkg: Add the MSR definition for the GHCB register
>>>>>>   MdePkg: Add a structure definition for the GHCB
>>>>>>   MdeModulePkg/DxeIplPeim: Support GHCB pages when creating page tables
>>>>>>   MdePkg/BaseLib: Add support for the XGETBV instruction
>>>>>>   MdePkg/BaseLib: Add support for the VMGEXIT instruction
>>>>>>   UefiCpuPkg: Implement library support for VMGEXIT
>>>>>>   OvmfPkg: Prepare OvmfPkg to use the VmgExitLib library
>>>>>>   UefiPayloadPkg: Prepare UefiPayloadPkg to use the VmgExitLib library
>>>>>>   UefiCpuPkg/CpuExceptionHandler: Add base support for the #VC exception
>>>>>>   OvmfPkg/VmgExitLib: Implement library support for VmgExitLib in OVMF
>>>>>>   OvmfPkg/VmgExitLib: Add support for IOIO_PROT NAE events
>>>>>>   OvmfPkg/VmgExitLib: Support string IO for IOIO_PROT NAE events
>>>>>>   OvmfPkg/VmgExitLib: Add support for CPUID NAE events
>>>>>>   OvmfPkg/VmgExitLib: Add support for MSR_PROT NAE events
>>>>>>   OvmfPkg/VmgExitLib: Add support for NPF NAE events (MMIO)
>>>>>>   OvmfPkg/VmgExitLib: Add support for WBINVD NAE events
>>>>>>   OvmfPkg/VmgExitLib: Add support for RDTSC NAE events
>>>>>>   OvmfPkg/VmgExitLib: Add support for RDPMC NAE events
>>>>>>   OvmfPkg/VmgExitLib: Add support for INVD NAE events
>>>>>>   OvmfPkg/VmgExitLib: Add support for VMMCALL NAE events
>>>>>>   OvmfPkg/VmgExitLib: Add support for RDTSCP NAE events
>>>>>>   OvmfPkg/VmgExitLib: Add support for MONITOR/MONITORX NAE events
>>>>>>   OvmfPkg/VmgExitLib: Add support for MWAIT/MWAITX NAE events
>>>>>>   OvmfPkg/VmgExitLib: Add support for DR7 Read/Write NAE events
>>>>>>   OvmfPkg/MemEncryptSevLib: Add an SEV-ES guest indicator function
>>>>>>   OvmfPkg: Add support to perform SEV-ES initialization
>>>>>>   OvmfPkg: Create a GHCB page for use during Sec phase
>>>>>>   OvmfPkg/PlatformPei: Reserve GHCB-related areas if S3 is supported
>>>>>>   OvmfPkg: Create GHCB pages for use during Pei and Dxe phase
>>>>>>   OvmfPkg/PlatformPei: Move early GDT into ram when SEV-ES is enabled
>>>>>>   UefiCpuPkg: Create an SEV-ES workarea PCD
>>>>>>   OvmfPkg: Reserve a page in memory for the SEV-ES usage
>>>>>>   OvmfPkg/PlatformPei: Reserve SEV-ES work area if S3 is supported
>>>>>>   OvmfPkg/ResetVector: Add support for a 32-bit SEV check
>>>>>>   OvmfPkg/Sec: Add #VC exception handling for Sec phase
>>>>>>   OvmfPkg/Sec: Enable cache early to speed up booting
>>>>>>   OvmfPkg/QemuFlashFvbServicesRuntimeDxe: Bypass flash detection with
>>>>>>     SEV-ES
>>>>>>   UefiCpuPkg: Add a 16-bit protected mode code segment descriptor
>>>>>>   UefiCpuPkg/MpInitLib: Add CPU MP data flag to indicate if SEV-ES is
>>>>>>     enabled
>>>>>>   UefiCpuPkg: Allow AP booting under SEV-ES
>>>>>>   OvmfPkg: Use the SEV-ES work area for the SEV-ES AP reset vector
>>>>>>   OvmfPkg: Move the GHCB allocations into reserved memory
>>>>>>   UefiCpuPkg/MpInitLib: Prepare SEV-ES guest APs for OS use
>>>>>>   Maintainers.txt: Add reviewers for the OvmfPkg SEV-related files
>>>>>>
>>>>>>  MdeModulePkg/MdeModulePkg.dec                 |    9 +
>>>>>>  OvmfPkg/OvmfPkg.dec                           |    9 +
>>>>>>  UefiCpuPkg/UefiCpuPkg.dec                     |   17 +
>>>>>>  OvmfPkg/OvmfPkgIa32.dsc                       |    6 +
>>>>>>  OvmfPkg/OvmfPkgIa32X64.dsc                    |    6 +
>>>>>>  OvmfPkg/OvmfPkgX64.dsc                        |    6 +
>>>>>>  OvmfPkg/OvmfXen.dsc                           |    1 +
>>>>>>  UefiCpuPkg/UefiCpuPkg.dsc                     |    2 +
>>>>>>  UefiPayloadPkg/UefiPayloadPkgIa32.dsc         |    2 +
>>>>>>  UefiPayloadPkg/UefiPayloadPkgIa32X64.dsc      |    2 +
>>>>>>  OvmfPkg/OvmfPkgX64.fdf                        |    9 +
>>>>>>  MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf       |    2 +
>>>>>>  MdePkg/Library/BaseLib/BaseLib.inf            |    4 +
>>>>>>  OvmfPkg/Library/VmgExitLib/VmgExitLib.inf     |   36 +
>>>>>>  OvmfPkg/PlatformPei/PlatformPei.inf           |    9 +
>>>>>>  .../FvbServicesRuntimeDxe.inf                 |    2 +
>>>>>>  OvmfPkg/ResetVector/ResetVector.inf           |    8 +
>>>>>>  OvmfPkg/Sec/SecMain.inf                       |    4 +
>>>>>>  .../DxeCpuExceptionHandlerLib.inf             |    1 +
>>>>>>  .../PeiCpuExceptionHandlerLib.inf             |    1 +
>>>>>>  .../SecPeiCpuExceptionHandlerLib.inf          |    1 +
>>>>>>  .../SmmCpuExceptionHandlerLib.inf             |    1 +
>>>>>>  .../Xcode5SecPeiCpuExceptionHandlerLib.inf    |    1 +
>>>>>>  UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf |    4 +
>>>>>>  UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf |    4 +
>>>>>>  .../Library/VmgExitLibNull/VmgExitLibNull.inf |   27 +
>>>>>>  .../Core/DxeIplPeim/X64/VirtualMemory.h       |   12 +-
>>>>>>  MdePkg/Include/Library/BaseLib.h              |   31 +
>>>>>>  MdePkg/Include/Register/Amd/Fam17Msr.h        |   46 +
>>>>>>  MdePkg/Include/Register/Amd/Ghcb.h            |  166 ++
>>>>>>  .../IndustryStandard/InstructionParsing.h     |   83 +
>>>>>>  OvmfPkg/Include/Library/MemEncryptSevLib.h    |   12 +
>>>>>>  .../QemuFlash.h                               |   13 +
>>>>>>  UefiCpuPkg/CpuDxe/CpuGdt.h                    |    4 +-
>>>>>>  UefiCpuPkg/Include/Library/VmgExitLib.h       |  103 +
>>>>>>  UefiCpuPkg/Library/MpInitLib/MpLib.h          |   68 +-
>>>>>>  .../Core/DxeIplPeim/Ia32/DxeLoadFunc.c        |    4 +-
>>>>>>  .../Core/DxeIplPeim/X64/DxeLoadFunc.c         |   11 +-
>>>>>>  .../Core/DxeIplPeim/X64/VirtualMemory.c       |   57 +-
>>>>>>  .../MemEncryptSevLibInternal.c                |   75 +-
>>>>>>  OvmfPkg/Library/VmgExitLib/VmgExitLib.c       |  159 ++
>>>>>>  OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c | 1716 +++++++++++++++++
>>>>>>  OvmfPkg/PlatformPei/AmdSev.c                  |   89 +
>>>>>>  OvmfPkg/PlatformPei/MemDetect.c               |   43 +
>>>>>>  .../QemuFlash.c                               |   23 +-
>>>>>>  .../QemuFlashDxe.c                            |   40 +
>>>>>>  .../QemuFlashSmm.c                            |   16 +
>>>>>>  OvmfPkg/Sec/SecMain.c                         |  188 +-
>>>>>>  UefiCpuPkg/CpuDxe/CpuGdt.c                    |    8 +-
>>>>>>  .../CpuExceptionCommon.c                      |   10 +-
>>>>>>  .../PeiDxeSmmCpuException.c                   |   20 +-
>>>>>>  .../SecPeiCpuException.c                      |   19 +
>>>>>>  UefiCpuPkg/Library/MpInitLib/DxeMpLib.c       |  120 +-
>>>>>>  UefiCpuPkg/Library/MpInitLib/MpLib.c          |  337 +++-
>>>>>>  UefiCpuPkg/Library/MpInitLib/PeiMpLib.c       |   19 +
>>>>>>  .../Library/VmgExitLibNull/VmgExitLibNull.c   |  121 ++
>>>>>>  UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c  |    2 +-
>>>>>>  Maintainers.txt                               |   10 +
>>>>>>  MdeModulePkg/MdeModulePkg.uni                 |    8 +
>>>>>>  MdePkg/Library/BaseLib/Ia32/VmgExit.nasm      |   38 +
>>>>>>  MdePkg/Library/BaseLib/Ia32/XGetBv.nasm       |   31 +
>>>>>>  MdePkg/Library/BaseLib/X64/VmgExit.nasm       |   32 +
>>>>>>  MdePkg/Library/BaseLib/X64/XGetBv.nasm        |   34 +
>>>>>>  OvmfPkg/ResetVector/Ia16/ResetVectorVtf0.asm  |  100 +
>>>>>>  OvmfPkg/ResetVector/Ia32/PageTables64.asm     |  351 +++-
>>>>>>  OvmfPkg/ResetVector/ResetVector.nasmb         |   20 +
>>>>>>  .../X64/ExceptionHandlerAsm.nasm              |   17 +
>>>>>>  .../X64/Xcode5ExceptionHandlerAsm.nasm        |   17 +
>>>>>>  UefiCpuPkg/Library/MpInitLib/Ia32/MpEqu.inc   |    2 +-
>>>>>>  .../Library/MpInitLib/Ia32/MpFuncs.nasm       |   20 +-
>>>>>>  UefiCpuPkg/Library/MpInitLib/X64/MpEqu.inc    |    4 +-
>>>>>>  UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm |  369 +++-
>>>>>>  .../Library/VmgExitLibNull/VmgExitLibNull.uni |   15 +
>>>>>>  .../ResetVector/Vtf0/Ia16/Real16ToFlat32.asm  |    9 +
>>>>>>  UefiCpuPkg/UefiCpuPkg.uni                     |   11 +
>>>>>>  75 files changed, 4777 insertions(+), 100 deletions(-)  create mode
>>>>>> 100644 OvmfPkg/Library/VmgExitLib/VmgExitLib.inf
>>>>>>  create mode 100644
>>>>>> UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.inf
>>>>>>  create mode 100644 MdePkg/Include/Register/Amd/Ghcb.h
>>>>>>  create mode 100644
>>>>>> OvmfPkg/Include/IndustryStandard/InstructionParsing.h
>>>>>>  create mode 100644 UefiCpuPkg/Include/Library/VmgExitLib.h
>>>>>>  create mode 100644 OvmfPkg/Library/VmgExitLib/VmgExitLib.c
>>>>>>  create mode 100644 OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
>>>>>>  create mode 100644
>>>>>> UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c
>>>>>>  create mode 100644 MdePkg/Library/BaseLib/Ia32/VmgExit.nasm
>>>>>>  create mode 100644 MdePkg/Library/BaseLib/Ia32/XGetBv.nasm
>>>>>>  create mode 100644 MdePkg/Library/BaseLib/X64/VmgExit.nasm
>>>>>>  create mode 100644 MdePkg/Library/BaseLib/X64/XGetBv.nasm
>>>>>>  create mode 100644 OvmfPkg/ResetVector/Ia16/ResetVectorVtf0.asm
>>>>>>  create mode 100644
>>>>>> UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.uni
>>>>>>
>>>>>
>>>>> For all patches except #10 ("UefiPayloadPkg: Prepare UefiPayloadPkg to use the VmgExitLib library") and #46 ("Maintainers.txt:
>> Add reviewers for the OvmfPkg SEV-related files"):
>>>>>
>>>>> Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
>>>>>
>>>>> Thanks
>>>>> Laszlo
>>>>>
>>>>
>>>
>>>
>>>
>>
>> 
>