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

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

On 12/12/19 1:01 AM, Ni, Ray wrote:
> 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)

No, I would need to read an MSR and I really should be certain the MSR is
valid before trying to do that - and that requires checking CPUID.

> 
> If no, can you define the PCD in UefiCpuPkg?

I should be able to do that. Let me give it a try.

Thanks,
Tom

> 
> 
>> -----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://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.tianocore.org%2Fshow_bug.cgi%3Fid%3D2198&amp;data=02%7C01%7Cthomas.lendacky%40amd.com%7C8541911e903d4d05cb4708d77ed10ec4%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637117308681418556&amp;sdata=Vt3vjZ7afbFWT59nR%2F332FMHm%2F%2FBkq62%2BN6oKEfiraE%3D&amp;reserved=0
>>
>> 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
>