Re: [PATCH v2 5/6] OvmfPkg/AmdSev: assign and protect the Sev Secret area

["Laszlo Ersek" <lersek@redhat.com>]

On 11/20/20 19:45, James Bottomley wrote:
> Create a one page secret area in the MEMFD and protect the area with a
> boot time HOB.
> 
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3077
> Signed-off-by: James Bottomley <jejb@linux.ibm.com>
> ---
>  OvmfPkg/AmdSev/AmdSevX64.dsc           |  1 +
>  OvmfPkg/AmdSev/AmdSevX64.fdf           |  4 +++
>  OvmfPkg/AmdSev/SecretPei/SecretPei.inf | 39 ++++++++++++++++++++++++++
>  OvmfPkg/AmdSev/SecretPei/SecretPei.c   | 25 +++++++++++++++++
>  4 files changed, 69 insertions(+)
>  create mode 100644 OvmfPkg/AmdSev/SecretPei/SecretPei.inf
>  create mode 100644 OvmfPkg/AmdSev/SecretPei/SecretPei.c
> 
> diff --git a/OvmfPkg/AmdSev/AmdSevX64.dsc b/OvmfPkg/AmdSev/AmdSevX64.dsc
> index c0b4e1b274fc..a3f75a626e5e 100644
> --- a/OvmfPkg/AmdSev/AmdSevX64.dsc
> +++ b/OvmfPkg/AmdSev/AmdSevX64.dsc
> @@ -624,6 +624,7 @@ [Components]
>      <LibraryClasses>
>    }
>    UefiCpuPkg/CpuMpPei/CpuMpPei.inf
> +  OvmfPkg/AmdSev/SecretPei/SecretPei.inf
>  
>  !if $(TPM_ENABLE) == TRUE
>    OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
> diff --git a/OvmfPkg/AmdSev/AmdSevX64.fdf b/OvmfPkg/AmdSev/AmdSevX64.fdf
> index 97f031950abd..c628e6d8f6e7 100644
> --- a/OvmfPkg/AmdSev/AmdSevX64.fdf
> +++ b/OvmfPkg/AmdSev/AmdSevX64.fdf
> @@ -59,6 +59,9 @@ [FD.MEMFD]
>  0x00B000|0x001000
>  gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaBase|gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaSize
>  
> +0x00C000|0x001000
> +gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretBase|gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretSize
> +
>  0x010000|0x010000
>  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamSize
>  
> @@ -138,6 +141,7 @@ [FV.PEIFV]
>  INF  MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf
>  INF  UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf
>  INF  UefiCpuPkg/CpuMpPei/CpuMpPei.inf
> +INF  OvmfPkg/AmdSev/SecretPei/SecretPei.inf
>  
>  !if $(TPM_ENABLE) == TRUE
>  INF  OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
> diff --git a/OvmfPkg/AmdSev/SecretPei/SecretPei.inf b/OvmfPkg/AmdSev/SecretPei/SecretPei.inf
> new file mode 100644
> index 000000000000..1b40ac036aba
> --- /dev/null
> +++ b/OvmfPkg/AmdSev/SecretPei/SecretPei.inf
> @@ -0,0 +1,39 @@
> +## @file
> +#  PEI support for SEV Secrets
> +#
> +#  Copyright (C) 2020 James Bottomley, IBM Corporation.
> +#
> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION                    = 0x00010005
> +  BASE_NAME                      = SecretPei
> +  FILE_GUID                      = 45260dde-0c3c-4b41-a226-ef3803fac7d4
> +  MODULE_TYPE                    = PEIM
> +  VERSION_STRING                 = 1.0
> +  ENTRY_POINT                    = InitializeSecretPei
> +
> +#
> +# The following information is for reference only and not required by the build tools.
> +#

(1) I'm very sorry, my previous point on this was unclear.

The above comment refers to the VALID_ARCHITECTURES (non-)macro.
Therefore, if we keep VALID_ARCHITECTURES, then it should be restricted
to X64, and the comment should stay. If we remove VALID_ARCHITECTURES,
then the comment becomes dangling -- and it should disappear too.

With this updated:

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Thanks
Laszlo

> +
> +[Sources]
> +  SecretPei.c
> +
> +[Packages]
> +  OvmfPkg/OvmfPkg.dec
> +  MdePkg/MdePkg.dec
> +
> +[LibraryClasses]
> +  HobLib
> +  PeimEntryPoint
> +  PcdLib
> +
> +[FixedPcd]
> +  gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretBase
> +  gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretSize
> +
> +[Depex]
> +  TRUE
> diff --git a/OvmfPkg/AmdSev/SecretPei/SecretPei.c b/OvmfPkg/AmdSev/SecretPei/SecretPei.c
> new file mode 100644
> index 000000000000..ad491515dd5d
> --- /dev/null
> +++ b/OvmfPkg/AmdSev/SecretPei/SecretPei.c
> @@ -0,0 +1,25 @@
> +/** @file
> +  SEV Secret boot time HOB placement
> +
> +  Copyright (C) 2020 James Bottomley, IBM Corporation.
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +#include <PiPei.h>
> +#include <Library/HobLib.h>
> +#include <Library/PcdLib.h>
> +
> +EFI_STATUS
> +EFIAPI
> +InitializeSecretPei (
> +  IN       EFI_PEI_FILE_HANDLE  FileHandle,
> +  IN CONST EFI_PEI_SERVICES     **PeiServices
> +  )
> +{
> +  BuildMemoryAllocationHob (
> +    PcdGet32 (PcdSevLaunchSecretBase),
> +    PcdGet32 (PcdSevLaunchSecretSize),
> +    EfiBootServicesData
> +    );
> +
> +  return EFI_SUCCESS;
> +}
>