Re: [PATCH V2] UefiCpuPkg/CpuCommonFeaturesLib: Aesni.c uses BIT0 and BIT1 reversedly

["Dong, Eric" <eric.dong@intel.com>]

Reviewed-by: Eric Dong <eric.dong@intel.com>

> -----Original Message-----
> From: Zeng, Star
> Sent: Thursday, March 14, 2019 12:24 PM
> To: edk2-devel@lists.01.org
> Cc: Zeng, Star <star.zeng@intel.com>; Laszlo Ersek <lersek@redhat.com>;
> Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>; Kumar,
> Chandana C <chandana.c.kumar@intel.com>
> Subject: [PATCH V2] UefiCpuPkg/CpuCommonFeaturesLib: Aesni.c uses BIT0
> and BIT1 reversedly
> 
> V2:
> Correct description "disable(0)/enable(1)" to "disable(1)/enable(0)".
> 
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1621
> 
> According to Intel SDM as below, the BIT0 should be treated as lock bit, and
> BIT1 should be treated as disable(1)/enable(0) bit.
> 
> "11b: AES instructions are not available until next RESET.
> Otherwise, AES instructions are available.
> If the configuration is not 01b, AES
> instructions can be mis-configured if a privileged agent unintentionally writes
> 11b"
> 
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Chandana Kumar <chandana.c.kumar@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Star Zeng <star.zeng@intel.com>
> ---
>  UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> index 56b1b551d977..3f7c933e51f4 100644
> --- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> @@ -1,7 +1,7 @@
>  /** @file
>    AESNI feature.
> 
> -  Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
> +  Copyright (c) 2017 - 2019, Intel Corporation. All rights
> + reserved.<BR>
>    This program and the accompanying materials
>    are licensed and made available under the terms and conditions of the BSD
> License
>    which accompanies this distribution.  The full text of the license may be
> found at @@ -123,7 +123,7 @@ AesniInitialize (
>          MSR_SANDY_BRIDGE_FEATURE_CONFIG,
>          MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER,
>          Bits.AESConfiguration,
> -        BIT1 | ((State) ? 0 : BIT0)
> +        BIT0 | ((State) ? 0 : BIT1)
>          );
>      }
>    }
> --
> 2.21.0.windows.1