Re: [RFC PATCH v3 35/43] UefiCpuPkg/MpInitLib: Add a CPU MP data flag to indicate if SEV-ES is enabled

["Ni, Ray" <ray.ni@intel.com>]

OK I see now the Enable PCD is defined in MdeModulePkg, produced in platform and consumed in MpInitLib.

Is there a way to easily detect whether SEV-ES is enabled? (without triggering CPUID as what SEC does)

If no, can you define the PCD in UefiCpuPkg?


> -----Original Message-----
> From: Tom Lendacky <thomas.lendacky@amd.com>
> Sent: Thursday, November 21, 2019 4:07 AM
> To: devel@edk2.groups.io
> Cc: Justen, Jordan L <jordan.l.justen@intel.com>; Laszlo Ersek <lersek@redhat.com>; Ard Biesheuvel
> <ard.biesheuvel@linaro.org>; Kinney, Michael D <michael.d.kinney@intel.com>; Gao, Liming <liming.gao@intel.com>; Dong,
> Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>; Brijesh Singh <brijesh.singh@amd.com>
> Subject: [RFC PATCH v3 35/43] UefiCpuPkg/MpInitLib: Add a CPU MP data flag to indicate if SEV-ES is enabled
> 
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198
> 
> When starting APs in an SMP configuration, the AP needs to know if it is
> running as an SEV-ES guest in order to assign a GHCB page.
> 
> Add a field to the CPU_MP_DATA structure that will indicate if SEV-ES is
> enabled. This new field is set during MP library initialization with the
> PCD value PcdSevEsIsEnabled. This flag can then be used to determine if
> SEV-ES is enabled.
> 
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
>  UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf | 1 +
>  UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf | 1 +
>  UefiCpuPkg/Library/MpInitLib/MpLib.h          | 2 ++
>  UefiCpuPkg/Library/MpInitLib/MpLib.c          | 1 +
>  4 files changed, 5 insertions(+)
> 
> diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
> index cd912ab0c5ee..f84dbb09ae49 100644
> --- a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
> +++ b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
> @@ -69,4 +69,5 @@ [Pcd]
>    gUefiCpuPkgTokenSpaceGuid.PcdCpuApLoopMode                       ## CONSUMES
>    gUefiCpuPkgTokenSpaceGuid.PcdCpuApTargetCstate                   ## SOMETIMES_CONSUMES
>    gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard                  ## CONSUMES
> +  gEfiMdeModulePkgTokenSpaceGuid.PcdSevEsIsEnabled                 ## CONSUMES
> 
> diff --git a/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf b/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf
> index 1538185ef99a..9c1215ec75d0 100644
> --- a/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf
> +++ b/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf
> @@ -60,6 +60,7 @@ [Pcd]
>    gUefiCpuPkgTokenSpaceGuid.PcdCpuMicrocodePatchRegionSize         ## CONSUMES
>    gUefiCpuPkgTokenSpaceGuid.PcdCpuApLoopMode                       ## CONSUMES
>    gUefiCpuPkgTokenSpaceGuid.PcdCpuApTargetCstate                   ## SOMETIMES_CONSUMES
> +  gEfiMdeModulePkgTokenSpaceGuid.PcdSevEsIsEnabled                 ## CONSUMES
> 
>  [Guids]
>    gEdkiiS3SmmInitDoneGuid
> diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h b/UefiCpuPkg/Library/MpInitLib/MpLib.h
> index 8fa07b12c5e1..c10fe894cf9b 100644
> --- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
> +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h
> @@ -259,6 +259,8 @@ struct _CPU_MP_DATA {
>    // driver.
>    //
>    BOOLEAN                        WakeUpByInitSipiSipi;
> +
> +  BOOLEAN                        SevEsIsEnabled;
>  };
> 
>  extern EFI_GUID mCpuInitMpLibHobGuid;
> diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> index 49be5d5385d9..aa25bf9b3671 100644
> --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> @@ -1708,6 +1708,7 @@ MpInitLibInitialize (
>      CpuMpData->MicrocodePatchAddress    = OldCpuMpData->MicrocodePatchAddress;
>    }
>    InitializeSpinLock(&CpuMpData->MpLock);
> +  CpuMpData->SevEsIsEnabled = PcdGetBool (PcdSevEsIsEnabled);
> 
>    //
>    // Make sure no memory usage outside of the allocated buffer.
> --
> 2.17.1