Re: [edk2-devel] [PATCH v13 00/32] Add AMD Secure Nested Paging (SEV-SNP) support

["Brijesh Singh" <brijesh.singh@amd.com>]

Hi Gerd and Jiewen,

Now that all the patches are ack'ed by Ray, can we plan to merge this 
series ?

-Brijesh


On 11/12/21 11:39 AM, Brijesh Singh via groups.io wrote:
> ---------------------------------------------------------------------------
> Hi Ray,
>    
> Thanks for your reviews and continuous support; I have updated a couple of patches
> to address your comment. As I said in my previous reply, I will working on a
> follow-up series to group some of those Sev specific variables in CpuData.
>        
> I hope that is okay with you.
>           
> thanks
> ----------------------------------------------------------------------------
> 
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275
> 
> SEV-SNP builds upon existing SEV and SEV-ES functionality while adding
> new hardware-based memory protections. SEV-SNP adds strong memory integrity
> protection to help prevent malicious hypervisor-based attacks like data
> replay, memory re-mapping and more in order to create an isolated memory
> encryption environment.
>   
> This series provides the basic building blocks to support booting the SEV-SNP
> VMs, it does not cover all the security enhancement introduced by the SEV-SNP
> such as interrupt protection.
> 
> Many of the integrity guarantees of SEV-SNP are enforced through a new
> structure called the Reverse Map Table (RMP). Adding a new page to SEV-SNP
> VM requires a 2-step process. First, the hypervisor assigns a page to the
> guest using the new RMPUPDATE instruction. This transitions the page to
> guest-invalid. Second, the guest validates the page using the new PVALIDATE
> instruction. The SEV-SNP VMs can use the new "Page State Change Request NAE"
> defined in the GHCB specification to ask hypervisor to add or remove page
> from the RMP table.
> 
> Each page assigned to the SEV-SNP VM can either be validated or unvalidated,
> as indicated by the Validated flag in the page's RMP entry. There are two
> approaches that can be taken for the page validation: Pre-validation and
> Lazy Validation.
> 
> Under pre-validation, the pages are validated prior to first use. And under
> lazy validation, pages are validated when first accessed. An access to a
> unvalidated page results in a #VC exception, at which time the exception
> handler may validate the page. Lazy validation requires careful tracking of
> the validated pages to avoid validating the same GPA more than once. The
> recently introduced "Unaccepted" memory type can be used to communicate the
> unvalidated memory ranges to the Guest OS.
> 
> At this time we only support the pre-validation. OVMF detects all the available
> system RAM in the PEI phase. When SEV-SNP is enabled, the memory is validated
> before it is made available to the EDK2 core.
> 
> Now that series contains all the basic support required to launch SEV-SNP
> guest. We are still missing the Interrupt security feature provided by the
> SNP. The feature will be added after the base support is accepted.
> 
> Additional resources
> ---------------------
> SEV-SNP whitepaper
> https://www.amd.com/system/files/TechDocs/SEV-SNP-strengthening-vm-isolation-with-integrity-protection-and-more.pdf
> 
> APM 2: https://www.amd.com/system/files/TechDocs/24593.pdf (section 15.36)
> 
> The complete source is available at
> https://github.com/AMDESE/ovmf/tree/snp-v13
> 
> GHCB spec:
> https://developer.amd.com/wp-content/resources/56421.pdf
> 
> SEV-SNP firmware specification:
> https://www.amd.com/system/files/TechDocs/56860.pdf
> 
> Change since v12:
>   * MpLib: Add comment to clarify that SEV-SNP enabled implicitly means SEV and SEV-ES are active.
>   * MpLib: Move the extended topology initialization in AmdSev.c
> 
> Change since v11:
>   * rebase to the latest
>   * fix the UefiCpuPkg PCD definition patch header.
> 
> Change since v10:
>   * fix 'unresolved external symbol __allshl' link error when building I32 for VS2017.
> 
> Changes since v9:
>   * Move CCAttrs Pcd define in MdePkg
>   * Add comment to indicate that allocating the identity map PT is temporary until we get lazy validation
> 
> Changes since v8:
>   * drop the generic metadata and make it specific to SEV.
> 
> Changes since v7:
>   * Move SEV specific changes in MpLib in AmdSev file
>   * Update the GHCB register function to not restore the GHCB MSR because
>     we were already in the MSR protocol mode.
>   * Drop the SNP name from PcdSnpSecPreValidate.
>   * Add new section for GHCB memory in the OVMF metadata.
> 
> Change since v6:
>   * Drop the SNP boot block GUID and switch to using the Metadata guided structure
>     proposed by Min in TDX series.
>   * Exclude the GHCB page from the pre-validated region. It simplifies the reset
>     vector code where we do not need to unvalidate the GHCB page.
>   * Now that GHCB page is not validated so move the VMPL check from reset vector
>     code to the MemEncryptSevLib on the first page validation.
>   * Introduce the ConfidentialComputingGuestAttr PCD to communicate which
>     memory encryption is active so that MpInitLib can make use of it.
>   * Drop the SEVES specific PCD as the information can be communicated via
>     the ConfidentialComputingGuestAttr.
>   * Move the SNP specific AP creation function in AmdSev.c.
>   * Define the SNP Blob GUID in a new file.
> 
> Change since v5:
>   * When possible use the CPUID value from CPUID page
>   * Move the SEV specific functions from SecMain.c in AmdSev.c
>   * Rebase to the latest code
>   * Add the review feedback from Yao.
> 
> Change since v4:
>   * Use the correct MSR for the SEV_STATUS
>   * Add VMPL-0 check
> 
> Change since v3:
>   * ResetVector: move all SEV specific code in AmdSev.asm and add macros to keep
>     the code readable.
>   * Drop extending the EsWorkArea to contain SNP specific state.
>   * Drop the GhcbGpa library and call the VmgExit directly to register GHCB GPA.
>   * Install the CC blob config table from AmdSevDxe instead of extending the
>     AmdSev/SecretsDxe for it.
>   * Add the separate PCDs for the SNP Secrets.
> 
> Changes since v2:
>   * Add support for the AP creation.
>   * Use the module-scoping override to make AmdSevDxe use the IO port for PCI reads.
>   * Use the reserved memory type for CPUID and Secrets page.
>   *
> Changes since v1:
>   * Drop the interval tree support to detect the pre-validated overlap region.
>   * Use an array to keep track of pre-validated regions.
>   * Add support to query the Hypervisor feature and verify that SNP feature is supported.
>   * Introduce MemEncryptSevClearMmioPageEncMask() to clear the C-bit from MMIO ranges.
>   * Pull the SevSecretDxe and SevSecretPei into OVMF package build.
>   * Extend the SevSecretDxe to expose confidential computing blob location through
>     EFI configuration table.
> 
> Brijesh Singh (28):
>    OvmfPkg/SecMain: move SEV specific routines in AmdSev.c
>    UefiCpuPkg/MpInitLib: move SEV specific routines in AmdSev.c
>    OvmfPkg/ResetVector: move clearing GHCB in SecMain
>    OvmfPkg/ResetVector: introduce SEV metadata descriptor for VMM use
>    OvmfPkg: reserve SNP secrets page
>    OvmfPkg: reserve CPUID page
>    OvmfPkg/ResetVector: pre-validate the data pages used in SEC phase
>    OvmfPkg/MemEncryptSevLib: add MemEncryptSevSnpEnabled()
>    OvmfPkg/SecMain: register GHCB gpa for the SEV-SNP guest
>    OvmfPkg/PlatformPei: register GHCB gpa for the SEV-SNP guest
>    OvmfPkg/AmdSevDxe: do not use extended PCI config space
>    OvmfPkg/MemEncryptSevLib: add support to validate system RAM
>    OvmfPkg/MemEncryptSevLib: add function to check the VMPL0
>    OvmfPkg/BaseMemEncryptSevLib: skip the pre-validated system RAM
>    OvmfPkg/MemEncryptSevLib: add support to validate > 4GB memory in PEI
>      phase
>    OvmfPkg/SecMain: validate the memory used for decompressing Fv
>    OvmfPkg/PlatformPei: validate the system RAM when SNP is active
>    MdePkg: Define ConfidentialComputingGuestAttr
>    OvmfPkg/PlatformPei: set PcdConfidentialComputingAttr when SEV is
>      active
>    UefiCpuPkg/MpInitLib: use PcdConfidentialComputingAttr to check SEV
>      status
>    UefiCpuPkg: add PcdGhcbHypervisorFeatures
>    OvmfPkg/PlatformPei: set the Hypervisor Features PCD
>    MdePkg/GHCB: increase the GHCB protocol max version
>    UefiCpuPkg/MpLib: add support to register GHCB GPA when SEV-SNP is
>      enabled
>    OvmfPkg/MemEncryptSevLib: change the page state in the RMP table
>    OvmfPkg/MemEncryptSevLib: skip page state change for Mmio address
>    OvmfPkg/PlatformPei: mark cpuid and secrets memory reserved in EFI map
>    OvmfPkg/AmdSev: expose the SNP reserved pages through configuration
>      table
> 
> Michael Roth (3):
>    OvmfPkg/ResetVector: use SEV-SNP-validated CPUID values
>    OvmfPkg/VmgExitLib: use SEV-SNP-validated CPUID values
>    UefiCpuPkg/MpInitLib: use BSP to do extended topology check
> 
> Tom Lendacky (1):
>    UefiCpuPkg/MpInitLib: Use SEV-SNP AP Creation NAE event to launch APs
> 
>   MdePkg/MdePkg.dec                             |   4 +
>   OvmfPkg/OvmfPkg.dec                           |  19 +
>   UefiCpuPkg/UefiCpuPkg.dec                     |   5 +
>   OvmfPkg/AmdSev/AmdSevX64.dsc                  |   8 +-
>   OvmfPkg/Bhyve/BhyveX64.dsc                    |   5 +-
>   OvmfPkg/OvmfPkgIa32.dsc                       |   4 +
>   OvmfPkg/OvmfPkgIa32X64.dsc                    |   9 +-
>   OvmfPkg/OvmfPkgX64.dsc                        |   8 +-
>   OvmfPkg/OvmfXen.dsc                           |   5 +-
>   OvmfPkg/OvmfPkgX64.fdf                        |   6 +
>   OvmfPkg/AmdSevDxe/AmdSevDxe.inf               |   7 +
>   .../DxeMemEncryptSevLib.inf                   |   3 +
>   .../PeiMemEncryptSevLib.inf                   |   7 +
>   .../SecMemEncryptSevLib.inf                   |   3 +
>   OvmfPkg/Library/VmgExitLib/SecVmgExitLib.inf  |   2 +
>   OvmfPkg/Library/VmgExitLib/VmgExitLib.inf     |   3 +
>   OvmfPkg/PlatformPei/PlatformPei.inf           |   7 +
>   OvmfPkg/ResetVector/ResetVector.inf           |   5 +
>   OvmfPkg/Sec/SecMain.inf                       |   4 +
>   UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf |   6 +-
>   UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf |   6 +-
>   .../Include/ConfidentialComputingGuestAttr.h  |  25 +
>   MdePkg/Include/Register/Amd/Ghcb.h            |   2 +-
>   .../Guid/ConfidentialComputingSevSnpBlob.h    |  33 ++
>   OvmfPkg/Include/Library/MemEncryptSevLib.h    |  26 +
>   .../X64/SnpPageStateChange.h                  |  36 ++
>   .../BaseMemEncryptSevLib/X64/VirtualMemory.h  |  24 +
>   OvmfPkg/PlatformPei/Platform.h                |   5 +
>   OvmfPkg/Sec/AmdSev.h                          |  95 ++++
>   UefiCpuPkg/Library/MpInitLib/MpLib.h          | 103 ++++
>   OvmfPkg/AmdSevDxe/AmdSevDxe.c                 |  23 +
>   .../DxeMemEncryptSevLibInternal.c             |  27 ++
>   .../Ia32/MemEncryptSevLib.c                   |  17 +
>   .../PeiMemEncryptSevLibInternal.c             |  27 ++
>   .../SecMemEncryptSevLibInternal.c             |  19 +
>   .../X64/DxeSnpSystemRamValidate.c             |  40 ++
>   .../X64/PeiDxeVirtualMemory.c                 | 167 ++++++-
>   .../X64/PeiSnpSystemRamValidate.c             | 127 +++++
>   .../X64/SecSnpSystemRamValidate.c             |  82 ++++
>   .../X64/SnpPageStateChangeInternal.c          | 294 ++++++++++++
>   OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c | 444 ++++++++++++++++--
>   OvmfPkg/PlatformPei/AmdSev.c                  | 231 +++++++++
>   OvmfPkg/PlatformPei/MemDetect.c               |   2 +
>   OvmfPkg/Sec/AmdSev.c                          | 298 ++++++++++++
>   OvmfPkg/Sec/SecMain.c                         | 158 +------
>   UefiCpuPkg/Library/MpInitLib/AmdSev.c         | 260 ++++++++++
>   UefiCpuPkg/Library/MpInitLib/DxeMpLib.c       |  16 +-
>   UefiCpuPkg/Library/MpInitLib/Ia32/AmdSev.c    |  70 +++
>   UefiCpuPkg/Library/MpInitLib/MpLib.c          | 347 +++++---------
>   UefiCpuPkg/Library/MpInitLib/PeiMpLib.c       |   4 +-
>   UefiCpuPkg/Library/MpInitLib/X64/AmdSev.c     | 261 ++++++++++
>   OvmfPkg/FvmainCompactScratchEnd.fdf.inc       |   5 +
>   OvmfPkg/ResetVector/Ia16/ResetVectorVtf0.asm  |  14 +
>   OvmfPkg/ResetVector/Ia32/AmdSev.asm           |  86 +++-
>   OvmfPkg/ResetVector/ResetVector.nasmb         |  18 +
>   OvmfPkg/ResetVector/X64/OvmfSevMetadata.asm   |  74 +++
>   UefiCpuPkg/Library/MpInitLib/MpEqu.inc        |   2 +
>   UefiCpuPkg/Library/MpInitLib/X64/AmdSev.nasm  | 200 ++++++++
>   UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm | 100 +---
>   59 files changed, 3360 insertions(+), 528 deletions(-)
>   create mode 100644 MdePkg/Include/ConfidentialComputingGuestAttr.h
>   create mode 100644 OvmfPkg/Include/Guid/ConfidentialComputingSevSnpBlob.h
>   create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/X64/SnpPageStateChange.h
>   create mode 100644 OvmfPkg/Sec/AmdSev.h
>   create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c
>   create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiSnpSystemRamValidate.c
>   create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/X64/SecSnpSystemRamValidate.c
>   create mode 100644 OvmfPkg/Library/BaseMemEncryptSevLib/X64/SnpPageStateChangeInternal.c
>   create mode 100644 OvmfPkg/Sec/AmdSev.c
>   create mode 100644 UefiCpuPkg/Library/MpInitLib/AmdSev.c
>   create mode 100644 UefiCpuPkg/Library/MpInitLib/Ia32/AmdSev.c
>   create mode 100644 UefiCpuPkg/Library/MpInitLib/X64/AmdSev.c
>   create mode 100644 OvmfPkg/ResetVector/X64/OvmfSevMetadata.asm
>   create mode 100644 UefiCpuPkg/Library/MpInitLib/X64/AmdSev.nasm
>