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* [PATCH] UefiCpuPkg CpuCommonFeaturesLib: Remove CPU generation check
@ 2019-05-16 10:33 Zeng, Star
  2019-05-16 13:06 ` Laszlo Ersek
  0 siblings, 1 reply; 9+ messages in thread
From: Zeng, Star @ 2019-05-16 10:33 UTC (permalink / raw)
  To: devel; +Cc: Star Zeng, Laszlo Ersek, Eric Dong, Ruiyu Ni, Chandana Kumar

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1679

The checking to CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI is enough,
the checking to CPU generation could be removed, then the code
could be reused by more platforms.

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>
Signed-off-by: Star Zeng <star.zeng@intel.com>
---
 UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
index b79446ba3ca9..4a56eec1b267 100644
--- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
+++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
@@ -57,15 +57,9 @@ AesniSupport (
   MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER   *MsrFeatureConfig;
 
   if (CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI == 1) {
-    if (IS_SANDY_BRIDGE_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
-        IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
-        IS_XEON_5600_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
-        IS_XEON_E7_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
-        IS_XEON_PHI_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel)) {
-      MsrFeatureConfig = (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
-      ASSERT (MsrFeatureConfig != NULL);
-      MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64 (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
-    }
+    MsrFeatureConfig = (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
+    ASSERT (MsrFeatureConfig != NULL);
+    MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64 (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
     return TRUE;
   }
   return FALSE;
-- 
2.21.0.windows.1


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH] UefiCpuPkg CpuCommonFeaturesLib: Remove CPU generation check
  2019-05-16 10:33 [PATCH] UefiCpuPkg CpuCommonFeaturesLib: Remove CPU generation check Zeng, Star
@ 2019-05-16 13:06 ` Laszlo Ersek
  2019-05-16 14:51   ` [edk2-devel] " Zeng, Star
  0 siblings, 1 reply; 9+ messages in thread
From: Laszlo Ersek @ 2019-05-16 13:06 UTC (permalink / raw)
  To: Star Zeng, devel; +Cc: Eric Dong, Ruiyu Ni, Chandana Kumar

Hi Star,

On 05/16/19 12:33, Star Zeng wrote:
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1679
> 
> The checking to CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI is enough,
> the checking to CPU generation could be removed, then the code
> could be reused by more platforms.
> 
> 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>
> Signed-off-by: Star Zeng <star.zeng@intel.com>
> ---
>  UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c | 12 +++---------
>  1 file changed, 3 insertions(+), 9 deletions(-)
> 
> diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> index b79446ba3ca9..4a56eec1b267 100644
> --- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> @@ -57,15 +57,9 @@ AesniSupport (
>    MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER   *MsrFeatureConfig;
>  
>    if (CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI == 1) {
> -    if (IS_SANDY_BRIDGE_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
> -        IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
> -        IS_XEON_5600_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
> -        IS_XEON_E7_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel) ||
> -        IS_XEON_PHI_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo->DisplayModel)) {
> -      MsrFeatureConfig = (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> -      ASSERT (MsrFeatureConfig != NULL);
> -      MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64 (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> -    }
> +    MsrFeatureConfig = (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> +    ASSERT (MsrFeatureConfig != NULL);
> +    MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64 (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
>      return TRUE;
>    }
>    return FALSE;
> 

the patch and the bugzilla ticket claim that the AESNI bit's presence in
CPUID guarantees that MSR 0x13C is available.

I don't see what guarantees this. According to the latest Intel SDM Vol
4, which I just downloaded (335592-069US, January 2019),
MSR_FEATURE_CONFIG is available on the following (DisplayFamily,
DisplayModel) pairs:

- 06_37H, 06_4AH, 06_4DH, 06_5AH, 06_5DH, 06_5CH, 06_7AH
- 06_25H, 06_2CH
- 06_2FH
- 06_2AH, 06_2DH
- 06_57H

Which seems to indicate that at least *the approach* of the original
code -- i.e. the family/model checking -- is correct. (It's possible
that the family/model list has to be extended from time to time, of course.)

Anyway, I don't intend to block this patch; OVMF does not use
CpuCommonFeaturesLib, so this change cannot regress it. I will let other
UefiCpuPkg reviewers decide about this patch.

Thanks!
Laszlo

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib: Remove CPU generation check
  2019-05-16 13:06 ` Laszlo Ersek
@ 2019-05-16 14:51   ` Zeng, Star
  2019-05-17  1:01     ` Dong, Eric
  2019-05-17  1:04     ` Ni, Ray
  0 siblings, 2 replies; 9+ messages in thread
From: Zeng, Star @ 2019-05-16 14:51 UTC (permalink / raw)
  To: devel@edk2.groups.io, lersek@redhat.com
  Cc: Dong, Eric, Ni, Ray, Kumar, Chandana C, Zeng, Star

Laszlo,

> -----Original Message-----
> From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of
> Laszlo Ersek
> Sent: Thursday, May 16, 2019 9:06 PM
> To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io
> Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>; Kumar,
> Chandana C <chandana.c.kumar@intel.com>
> Subject: Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> Remove CPU generation check
> 
> Hi Star,
> 
> On 05/16/19 12:33, Star Zeng wrote:
> > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1679
> >
> > The checking to CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI is enough, the
> > checking to CPU generation could be removed, then the code could be
> > reused by more platforms.
> >
> > 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>
> > Signed-off-by: Star Zeng <star.zeng@intel.com>
> > ---
> >  UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c | 12 +++---------
> >  1 file changed, 3 insertions(+), 9 deletions(-)
> >
> > diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > index b79446ba3ca9..4a56eec1b267 100644
> > --- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > @@ -57,15 +57,9 @@ AesniSupport (
> >    MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER   *MsrFeatureConfig;
> >
> >    if (CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI == 1) {
> > -    if (IS_SANDY_BRIDGE_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> >DisplayModel) ||
> > -        IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> >DisplayModel) ||
> > -        IS_XEON_5600_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> >DisplayModel) ||
> > -        IS_XEON_E7_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> >DisplayModel) ||
> > -        IS_XEON_PHI_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> >DisplayModel)) {
> > -      MsrFeatureConfig =
> (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > -      ASSERT (MsrFeatureConfig != NULL);
> > -      MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> > -    }
> > +    MsrFeatureConfig =
> (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > +    ASSERT (MsrFeatureConfig != NULL);
> > +    MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> > + (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> >      return TRUE;
> >    }
> >    return FALSE;
> >
> 
> the patch and the bugzilla ticket claim that the AESNI bit's presence in CPUID
> guarantees that MSR 0x13C is available.

That is the case we met. The purpose of this patch is to make the code more usable.

> 
> I don't see what guarantees this. According to the latest Intel SDM Vol 4,
> which I just downloaded (335592-069US, January 2019),
> MSR_FEATURE_CONFIG is available on the following (DisplayFamily,
> DisplayModel) pairs:
> 
> - 06_37H, 06_4AH, 06_4DH, 06_5AH, 06_5DH, 06_5CH, 06_7AH
> - 06_25H, 06_2CH
> - 06_2FH
> - 06_2AH, 06_2DH
> - 06_57H

Yes, right.

Let me show some examples for the generations not in the list above.

1. MSR 0x13C is available: our some internal generations are in this case.
Without the patch, code needs to use function level override method in a CpuSpecificFeaturesLib.
    Status = RegisterCpuFeature (
               "AESNI",
               NULL,                                         // Use core function
               SpecificAesniSupport,                         // Override core function
               NULL,                                         // Use core function
               CPU_FEATURE_AESNI,
               CPU_FEATURE_END
               );
With the patch, the function level override will be not needed. The benefit of this patch is here.

2. MSR 0x13C is not available: let's assume some other MSR will be available for the case.
Without or with the patch, codes both need to use function level override method in a CpuSpecificFeaturesLib.
    Status = RegisterCpuFeature (
               "AESNI",
               NULL,                                         // Use core function
               SpecificAesniSupport,                         // Override core function
               SpecificAesniInitialize,                         // Override core function
               CPU_FEATURE_AESNI,
               CPU_FEATURE_END
               );


Thanks,
Star

> 
> Which seems to indicate that at least *the approach* of the original code --
> i.e. the family/model checking -- is correct. (It's possible that the
> family/model list has to be extended from time to time, of course.)
> 
> Anyway, I don't intend to block this patch; OVMF does not use
> CpuCommonFeaturesLib, so this change cannot regress it. I will let other
> UefiCpuPkg reviewers decide about this patch.
> 
> Thanks!
> Laszlo
> 
> 


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib: Remove CPU generation check
  2019-05-16 14:51   ` [edk2-devel] " Zeng, Star
@ 2019-05-17  1:01     ` Dong, Eric
  2019-05-17  1:04     ` Ni, Ray
  1 sibling, 0 replies; 9+ messages in thread
From: Dong, Eric @ 2019-05-17  1:01 UTC (permalink / raw)
  To: Zeng, Star, devel@edk2.groups.io, lersek@redhat.com
  Cc: Ni, Ray, Kumar, Chandana C

Hi Star,

I agree with Laszlo's comments. Just remove the generation check logic is not a correct approach. We also have another Bugz reported the similar issue https://bugzilla.tianocore.org/show_bug.cgi?id=591

I think maybe we can follow that bugz request to default enable the feature and disable it for some specific generation.

Thanks,
Eric

> -----Original Message-----
> From: Zeng, Star
> Sent: Thursday, May 16, 2019 10:52 PM
> To: devel@edk2.groups.io; lersek@redhat.com
> Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>; Kumar,
> Chandana C <chandana.c.kumar@intel.com>; Zeng, Star
> <star.zeng@intel.com>
> Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> Remove CPU generation check
> 
> Laszlo,
> 
> > -----Original Message-----
> > From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of
> > Laszlo Ersek
> > Sent: Thursday, May 16, 2019 9:06 PM
> > To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io
> > Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>;
> > Kumar, Chandana C <chandana.c.kumar@intel.com>
> > Subject: Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> > Remove CPU generation check
> >
> > Hi Star,
> >
> > On 05/16/19 12:33, Star Zeng wrote:
> > > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1679
> > >
> > > The checking to CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI is enough,
> > > the checking to CPU generation could be removed, then the code could
> > > be reused by more platforms.
> > >
> > > 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>
> > > Signed-off-by: Star Zeng <star.zeng@intel.com>
> > > ---
> > >  UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c | 12 +++---------
> > >  1 file changed, 3 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > index b79446ba3ca9..4a56eec1b267 100644
> > > --- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > @@ -57,15 +57,9 @@ AesniSupport (
> > >    MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER
> *MsrFeatureConfig;
> > >
> > >    if (CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI == 1) {
> > > -    if (IS_SANDY_BRIDGE_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > >DisplayModel) ||
> > > -        IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > >DisplayModel) ||
> > > -        IS_XEON_5600_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > >DisplayModel) ||
> > > -        IS_XEON_E7_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > >DisplayModel) ||
> > > -        IS_XEON_PHI_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > >DisplayModel)) {
> > > -      MsrFeatureConfig =
> > (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > > -      ASSERT (MsrFeatureConfig != NULL);
> > > -      MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> > (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> > > -    }
> > > +    MsrFeatureConfig =
> > (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > > +    ASSERT (MsrFeatureConfig != NULL);
> > > +    MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> > > + (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> > >      return TRUE;
> > >    }
> > >    return FALSE;
> > >
> >
> > the patch and the bugzilla ticket claim that the AESNI bit's presence
> > in CPUID guarantees that MSR 0x13C is available.
> 
> That is the case we met. The purpose of this patch is to make the code more
> usable.
> 
> >
> > I don't see what guarantees this. According to the latest Intel SDM
> > Vol 4, which I just downloaded (335592-069US, January 2019),
> > MSR_FEATURE_CONFIG is available on the following (DisplayFamily,
> > DisplayModel) pairs:
> >
> > - 06_37H, 06_4AH, 06_4DH, 06_5AH, 06_5DH, 06_5CH, 06_7AH
> > - 06_25H, 06_2CH
> > - 06_2FH
> > - 06_2AH, 06_2DH
> > - 06_57H
> 
> Yes, right.
> 
> Let me show some examples for the generations not in the list above.
> 
> 1. MSR 0x13C is available: our some internal generations are in this case.
> Without the patch, code needs to use function level override method in a
> CpuSpecificFeaturesLib.
>     Status = RegisterCpuFeature (
>                "AESNI",
>                NULL,                                         // Use core function
>                SpecificAesniSupport,                         // Override core function
>                NULL,                                         // Use core function
>                CPU_FEATURE_AESNI,
>                CPU_FEATURE_END
>                );
> With the patch, the function level override will be not needed. The benefit of
> this patch is here.
> 
> 2. MSR 0x13C is not available: let's assume some other MSR will be available
> for the case.
> Without or with the patch, codes both need to use function level override
> method in a CpuSpecificFeaturesLib.
>     Status = RegisterCpuFeature (
>                "AESNI",
>                NULL,                                         // Use core function
>                SpecificAesniSupport,                         // Override core function
>                SpecificAesniInitialize,                         // Override core function
>                CPU_FEATURE_AESNI,
>                CPU_FEATURE_END
>                );
> 
> 
> Thanks,
> Star
> 
> >
> > Which seems to indicate that at least *the approach* of the original
> > code -- i.e. the family/model checking -- is correct. (It's possible
> > that the family/model list has to be extended from time to time, of
> > course.)
> >
> > Anyway, I don't intend to block this patch; OVMF does not use
> > CpuCommonFeaturesLib, so this change cannot regress it. I will let
> > other UefiCpuPkg reviewers decide about this patch.
> >
> > Thanks!
> > Laszlo
> >
> > 


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib: Remove CPU generation check
  2019-05-16 14:51   ` [edk2-devel] " Zeng, Star
  2019-05-17  1:01     ` Dong, Eric
@ 2019-05-17  1:04     ` Ni, Ray
  2019-05-17  3:05       ` Zeng, Star
  1 sibling, 1 reply; 9+ messages in thread
From: Ni, Ray @ 2019-05-17  1:04 UTC (permalink / raw)
  To: Zeng, Star, devel@edk2.groups.io, lersek@redhat.com
  Cc: Dong, Eric, Kumar, Chandana C

Star,
I think the discussion is about providing the evidence to support removing the generation check.
Not just the benefit of that.

Thanks,
Ray

> -----Original Message-----
> From: Zeng, Star
> Sent: Thursday, May 16, 2019 10:52 PM
> To: devel@edk2.groups.io; lersek@redhat.com
> Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>; Kumar,
> Chandana C <chandana.c.kumar@intel.com>; Zeng, Star
> <star.zeng@intel.com>
> Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> Remove CPU generation check
> 
> Laszlo,
> 
> > -----Original Message-----
> > From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of
> > Laszlo Ersek
> > Sent: Thursday, May 16, 2019 9:06 PM
> > To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io
> > Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>;
> > Kumar, Chandana C <chandana.c.kumar@intel.com>
> > Subject: Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> > Remove CPU generation check
> >
> > Hi Star,
> >
> > On 05/16/19 12:33, Star Zeng wrote:
> > > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1679
> > >
> > > The checking to CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI is enough,
> > > the checking to CPU generation could be removed, then the code could
> > > be reused by more platforms.
> > >
> > > 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>
> > > Signed-off-by: Star Zeng <star.zeng@intel.com>
> > > ---
> > >  UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c | 12 +++---------
> > >  1 file changed, 3 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > index b79446ba3ca9..4a56eec1b267 100644
> > > --- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > @@ -57,15 +57,9 @@ AesniSupport (
> > >    MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER
> *MsrFeatureConfig;
> > >
> > >    if (CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI == 1) {
> > > -    if (IS_SANDY_BRIDGE_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > >DisplayModel) ||
> > > -        IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > >DisplayModel) ||
> > > -        IS_XEON_5600_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > >DisplayModel) ||
> > > -        IS_XEON_E7_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > >DisplayModel) ||
> > > -        IS_XEON_PHI_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > >DisplayModel)) {
> > > -      MsrFeatureConfig =
> > (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > > -      ASSERT (MsrFeatureConfig != NULL);
> > > -      MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> > (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> > > -    }
> > > +    MsrFeatureConfig =
> > (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > > +    ASSERT (MsrFeatureConfig != NULL);
> > > +    MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> > > + (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> > >      return TRUE;
> > >    }
> > >    return FALSE;
> > >
> >
> > the patch and the bugzilla ticket claim that the AESNI bit's presence
> > in CPUID guarantees that MSR 0x13C is available.
> 
> That is the case we met. The purpose of this patch is to make the code more
> usable.
> 
> >
> > I don't see what guarantees this. According to the latest Intel SDM
> > Vol 4, which I just downloaded (335592-069US, January 2019),
> > MSR_FEATURE_CONFIG is available on the following (DisplayFamily,
> > DisplayModel) pairs:
> >
> > - 06_37H, 06_4AH, 06_4DH, 06_5AH, 06_5DH, 06_5CH, 06_7AH
> > - 06_25H, 06_2CH
> > - 06_2FH
> > - 06_2AH, 06_2DH
> > - 06_57H
> 
> Yes, right.
> 
> Let me show some examples for the generations not in the list above.
> 
> 1. MSR 0x13C is available: our some internal generations are in this case.
> Without the patch, code needs to use function level override method in a
> CpuSpecificFeaturesLib.
>     Status = RegisterCpuFeature (
>                "AESNI",
>                NULL,                                         // Use core function
>                SpecificAesniSupport,                         // Override core function
>                NULL,                                         // Use core function
>                CPU_FEATURE_AESNI,
>                CPU_FEATURE_END
>                );
> With the patch, the function level override will be not needed. The benefit
> of this patch is here.
> 
> 2. MSR 0x13C is not available: let's assume some other MSR will be available
> for the case.
> Without or with the patch, codes both need to use function level override
> method in a CpuSpecificFeaturesLib.
>     Status = RegisterCpuFeature (
>                "AESNI",
>                NULL,                                         // Use core function
>                SpecificAesniSupport,                         // Override core function
>                SpecificAesniInitialize,                         // Override core function
>                CPU_FEATURE_AESNI,
>                CPU_FEATURE_END
>                );
> 
> 
> Thanks,
> Star
> 
> >
> > Which seems to indicate that at least *the approach* of the original
> > code -- i.e. the family/model checking -- is correct. (It's possible
> > that the family/model list has to be extended from time to time, of
> > course.)
> >
> > Anyway, I don't intend to block this patch; OVMF does not use
> > CpuCommonFeaturesLib, so this change cannot regress it. I will let
> > other UefiCpuPkg reviewers decide about this patch.
> >
> > Thanks!
> > Laszlo
> >
> > 


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib: Remove CPU generation check
  2019-05-17  1:04     ` Ni, Ray
@ 2019-05-17  3:05       ` Zeng, Star
  2019-05-17 12:13         ` Laszlo Ersek
  2019-05-17 13:10         ` Ni, Ray
  0 siblings, 2 replies; 9+ messages in thread
From: Zeng, Star @ 2019-05-17  3:05 UTC (permalink / raw)
  To: Ni, Ray, devel@edk2.groups.io, lersek@redhat.com
  Cc: Dong, Eric, Kumar, Chandana C, Li, Kevin Y, Zeng, Star

Situation: All the generations (including the internal generations not listed in SDM) we saw have MSR 13Ch available when CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI == 1.

Requirement: Reuse more code.

Could you help think the good method and even propose the patch for that? I am ok to any method to improve the code's reusability.
Otherwise, we can only use function level override method ina CpuSpecificFeaturesLib.
    Status = RegisterCpuFeature (
               "AESNI",
               NULL,                                         // Use core function
               SpecificAesniSupport,                         // Override core function
               NULL,                                         // Use core function
               CPU_FEATURE_AESNI,
               CPU_FEATURE_END
               );

Thanks,
Star
> -----Original Message-----
> From: Ni, Ray
> Sent: Friday, May 17, 2019 9:04 AM
> To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io;
> lersek@redhat.com
> Cc: Dong, Eric <eric.dong@intel.com>; Kumar, Chandana C
> <chandana.c.kumar@intel.com>
> Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> Remove CPU generation check
> 
> Star,
> I think the discussion is about providing the evidence to support removing
> the generation check.
> Not just the benefit of that.
> 
> Thanks,
> Ray
> 
> > -----Original Message-----
> > From: Zeng, Star
> > Sent: Thursday, May 16, 2019 10:52 PM
> > To: devel@edk2.groups.io; lersek@redhat.com
> > Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>;
> > Kumar, Chandana C <chandana.c.kumar@intel.com>; Zeng, Star
> > <star.zeng@intel.com>
> > Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> > Remove CPU generation check
> >
> > Laszlo,
> >
> > > -----Original Message-----
> > > From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf
> > > Of Laszlo Ersek
> > > Sent: Thursday, May 16, 2019 9:06 PM
> > > To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io
> > > Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>;
> > > Kumar, Chandana C <chandana.c.kumar@intel.com>
> > > Subject: Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> > > Remove CPU generation check
> > >
> > > Hi Star,
> > >
> > > On 05/16/19 12:33, Star Zeng wrote:
> > > > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1679
> > > >
> > > > The checking to CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI is enough,
> > > > the checking to CPU generation could be removed, then the code
> > > > could be reused by more platforms.
> > > >
> > > > 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>
> > > > Signed-off-by: Star Zeng <star.zeng@intel.com>
> > > > ---
> > > >  UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c | 12 +++---------
> > > >  1 file changed, 3 insertions(+), 9 deletions(-)
> > > >
> > > > diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > index b79446ba3ca9..4a56eec1b267 100644
> > > > --- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > @@ -57,15 +57,9 @@ AesniSupport (
> > > >    MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER
> > *MsrFeatureConfig;
> > > >
> > > >    if (CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI == 1) {
> > > > -    if (IS_SANDY_BRIDGE_PROCESSOR (CpuInfo->DisplayFamily,
> CpuInfo-
> > > >DisplayModel) ||
> > > > -        IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > > >DisplayModel) ||
> > > > -        IS_XEON_5600_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > > >DisplayModel) ||
> > > > -        IS_XEON_E7_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > > >DisplayModel) ||
> > > > -        IS_XEON_PHI_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > > >DisplayModel)) {
> > > > -      MsrFeatureConfig =
> > > (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > > > -      ASSERT (MsrFeatureConfig != NULL);
> > > > -      MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> > > (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> > > > -    }
> > > > +    MsrFeatureConfig =
> > > (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > > > +    ASSERT (MsrFeatureConfig != NULL);
> > > > +    MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> > > > + (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> > > >      return TRUE;
> > > >    }
> > > >    return FALSE;
> > > >
> > >
> > > the patch and the bugzilla ticket claim that the AESNI bit's
> > > presence in CPUID guarantees that MSR 0x13C is available.
> >
> > That is the case we met. The purpose of this patch is to make the code
> > more usable.
> >
> > >
> > > I don't see what guarantees this. According to the latest Intel SDM
> > > Vol 4, which I just downloaded (335592-069US, January 2019),
> > > MSR_FEATURE_CONFIG is available on the following (DisplayFamily,
> > > DisplayModel) pairs:
> > >
> > > - 06_37H, 06_4AH, 06_4DH, 06_5AH, 06_5DH, 06_5CH, 06_7AH
> > > - 06_25H, 06_2CH
> > > - 06_2FH
> > > - 06_2AH, 06_2DH
> > > - 06_57H
> >
> > Yes, right.
> >
> > Let me show some examples for the generations not in the list above.
> >
> > 1. MSR 0x13C is available: our some internal generations are in this case.
> > Without the patch, code needs to use function level override method in
> > a CpuSpecificFeaturesLib.
> >     Status = RegisterCpuFeature (
> >                "AESNI",
> >                NULL,                                         // Use core function
> >                SpecificAesniSupport,                         // Override core function
> >                NULL,                                         // Use core function
> >                CPU_FEATURE_AESNI,
> >                CPU_FEATURE_END
> >                );
> > With the patch, the function level override will be not needed. The
> > benefit of this patch is here.
> >
> > 2. MSR 0x13C is not available: let's assume some other MSR will be
> > available for the case.
> > Without or with the patch, codes both need to use function level
> > override method in a CpuSpecificFeaturesLib.
> >     Status = RegisterCpuFeature (
> >                "AESNI",
> >                NULL,                                         // Use core function
> >                SpecificAesniSupport,                         // Override core function
> >                SpecificAesniInitialize,                         // Override core function
> >                CPU_FEATURE_AESNI,
> >                CPU_FEATURE_END
> >                );
> >
> >
> > Thanks,
> > Star
> >
> > >
> > > Which seems to indicate that at least *the approach* of the original
> > > code -- i.e. the family/model checking -- is correct. (It's possible
> > > that the family/model list has to be extended from time to time, of
> > > course.)
> > >
> > > Anyway, I don't intend to block this patch; OVMF does not use
> > > CpuCommonFeaturesLib, so this change cannot regress it. I will let
> > > other UefiCpuPkg reviewers decide about this patch.
> > >
> > > Thanks!
> > > Laszlo
> > >
> > > 


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib: Remove CPU generation check
  2019-05-17  3:05       ` Zeng, Star
@ 2019-05-17 12:13         ` Laszlo Ersek
  2019-05-17 13:10         ` Ni, Ray
  1 sibling, 0 replies; 9+ messages in thread
From: Laszlo Ersek @ 2019-05-17 12:13 UTC (permalink / raw)
  To: Zeng, Star, Ni, Ray, devel@edk2.groups.io
  Cc: Dong, Eric, Kumar, Chandana C, Li, Kevin Y

Hi Star,

On 05/17/19 05:05, Zeng, Star wrote:
> Situation: All the generations (including the internal generations not listed in SDM) we saw have MSR 13Ch available when CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI == 1.

This is a very accurate description, thank you; and it's exactly what I
feel is insufficient. "All generations we've seen" is not equal to "all
generations that (a) have ever existed plus (b) will ever exist".

Anyway, I now understand the motivation behind the patch, thanks. Given
that OVMF cannot be regressed by it, I don't intend to block it -- I
defer to other UefiCpuPkg reviewers. If they are OK with the patch, so am I.

Thanks!
Laszlo

> 
> Requirement: Reuse more code.
> 
> Could you help think the good method and even propose the patch for that? I am ok to any method to improve the code's reusability.
> Otherwise, we can only use function level override method ina CpuSpecificFeaturesLib.
>     Status = RegisterCpuFeature (
>                "AESNI",
>                NULL,                                         // Use core function
>                SpecificAesniSupport,                         // Override core function
>                NULL,                                         // Use core function
>                CPU_FEATURE_AESNI,
>                CPU_FEATURE_END
>                );
> 
> Thanks,
> Star
>> -----Original Message-----
>> From: Ni, Ray
>> Sent: Friday, May 17, 2019 9:04 AM
>> To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io;
>> lersek@redhat.com
>> Cc: Dong, Eric <eric.dong@intel.com>; Kumar, Chandana C
>> <chandana.c.kumar@intel.com>
>> Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
>> Remove CPU generation check
>>
>> Star,
>> I think the discussion is about providing the evidence to support removing
>> the generation check.
>> Not just the benefit of that.
>>
>> Thanks,
>> Ray
>>
>>> -----Original Message-----
>>> From: Zeng, Star
>>> Sent: Thursday, May 16, 2019 10:52 PM
>>> To: devel@edk2.groups.io; lersek@redhat.com
>>> Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>;
>>> Kumar, Chandana C <chandana.c.kumar@intel.com>; Zeng, Star
>>> <star.zeng@intel.com>
>>> Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
>>> Remove CPU generation check
>>>
>>> Laszlo,
>>>
>>>> -----Original Message-----
>>>> From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf
>>>> Of Laszlo Ersek
>>>> Sent: Thursday, May 16, 2019 9:06 PM
>>>> To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io
>>>> Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>;
>>>> Kumar, Chandana C <chandana.c.kumar@intel.com>
>>>> Subject: Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
>>>> Remove CPU generation check
>>>>
>>>> Hi Star,
>>>>
>>>> On 05/16/19 12:33, Star Zeng wrote:
>>>>> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1679
>>>>>
>>>>> The checking to CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI is enough,
>>>>> the checking to CPU generation could be removed, then the code
>>>>> could be reused by more platforms.
>>>>>
>>>>> 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>
>>>>> Signed-off-by: Star Zeng <star.zeng@intel.com>
>>>>> ---
>>>>>  UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c | 12 +++---------
>>>>>  1 file changed, 3 insertions(+), 9 deletions(-)
>>>>>
>>>>> diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
>>>>> b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
>>>>> index b79446ba3ca9..4a56eec1b267 100644
>>>>> --- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
>>>>> +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
>>>>> @@ -57,15 +57,9 @@ AesniSupport (
>>>>>    MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER
>>> *MsrFeatureConfig;
>>>>>
>>>>>    if (CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI == 1) {
>>>>> -    if (IS_SANDY_BRIDGE_PROCESSOR (CpuInfo->DisplayFamily,
>> CpuInfo-
>>>>> DisplayModel) ||
>>>>> -        IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
>>>>> DisplayModel) ||
>>>>> -        IS_XEON_5600_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
>>>>> DisplayModel) ||
>>>>> -        IS_XEON_E7_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
>>>>> DisplayModel) ||
>>>>> -        IS_XEON_PHI_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
>>>>> DisplayModel)) {
>>>>> -      MsrFeatureConfig =
>>>> (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
>>>>> -      ASSERT (MsrFeatureConfig != NULL);
>>>>> -      MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
>>>> (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
>>>>> -    }
>>>>> +    MsrFeatureConfig =
>>>> (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
>>>>> +    ASSERT (MsrFeatureConfig != NULL);
>>>>> +    MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
>>>>> + (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
>>>>>      return TRUE;
>>>>>    }
>>>>>    return FALSE;
>>>>>
>>>>
>>>> the patch and the bugzilla ticket claim that the AESNI bit's
>>>> presence in CPUID guarantees that MSR 0x13C is available.
>>>
>>> That is the case we met. The purpose of this patch is to make the code
>>> more usable.
>>>
>>>>
>>>> I don't see what guarantees this. According to the latest Intel SDM
>>>> Vol 4, which I just downloaded (335592-069US, January 2019),
>>>> MSR_FEATURE_CONFIG is available on the following (DisplayFamily,
>>>> DisplayModel) pairs:
>>>>
>>>> - 06_37H, 06_4AH, 06_4DH, 06_5AH, 06_5DH, 06_5CH, 06_7AH
>>>> - 06_25H, 06_2CH
>>>> - 06_2FH
>>>> - 06_2AH, 06_2DH
>>>> - 06_57H
>>>
>>> Yes, right.
>>>
>>> Let me show some examples for the generations not in the list above.
>>>
>>> 1. MSR 0x13C is available: our some internal generations are in this case.
>>> Without the patch, code needs to use function level override method in
>>> a CpuSpecificFeaturesLib.
>>>     Status = RegisterCpuFeature (
>>>                "AESNI",
>>>                NULL,                                         // Use core function
>>>                SpecificAesniSupport,                         // Override core function
>>>                NULL,                                         // Use core function
>>>                CPU_FEATURE_AESNI,
>>>                CPU_FEATURE_END
>>>                );
>>> With the patch, the function level override will be not needed. The
>>> benefit of this patch is here.
>>>
>>> 2. MSR 0x13C is not available: let's assume some other MSR will be
>>> available for the case.
>>> Without or with the patch, codes both need to use function level
>>> override method in a CpuSpecificFeaturesLib.
>>>     Status = RegisterCpuFeature (
>>>                "AESNI",
>>>                NULL,                                         // Use core function
>>>                SpecificAesniSupport,                         // Override core function
>>>                SpecificAesniInitialize,                         // Override core function
>>>                CPU_FEATURE_AESNI,
>>>                CPU_FEATURE_END
>>>                );
>>>
>>>
>>> Thanks,
>>> Star
>>>
>>>>
>>>> Which seems to indicate that at least *the approach* of the original
>>>> code -- i.e. the family/model checking -- is correct. (It's possible
>>>> that the family/model list has to be extended from time to time, of
>>>> course.)
>>>>
>>>> Anyway, I don't intend to block this patch; OVMF does not use
>>>> CpuCommonFeaturesLib, so this change cannot regress it. I will let
>>>> other UefiCpuPkg reviewers decide about this patch.
>>>>
>>>> Thanks!
>>>> Laszlo
>>>>
>>>> 
> 


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib: Remove CPU generation check
  2019-05-17  3:05       ` Zeng, Star
  2019-05-17 12:13         ` Laszlo Ersek
@ 2019-05-17 13:10         ` Ni, Ray
  2019-05-18  5:51           ` Zeng, Star
  1 sibling, 1 reply; 9+ messages in thread
From: Ni, Ray @ 2019-05-17 13:10 UTC (permalink / raw)
  To: Zeng, Star, devel@edk2.groups.io, lersek@redhat.com
  Cc: Dong, Eric, Kumar, Chandana C, Li, Kevin Y

Star,
I understand the motivation of the change.

Given your statement that all processors you met follows the rule,
and I know that you are currently working very actively on Intel processors,
Reviewed-by: Ray Ni <ray.ni@intel.com>

> -----Original Message-----
> From: Zeng, Star
> Sent: Friday, May 17, 2019 11:05 AM
> To: Ni, Ray <ray.ni@intel.com>; devel@edk2.groups.io; lersek@redhat.com
> Cc: Dong, Eric <eric.dong@intel.com>; Kumar, Chandana C
> <chandana.c.kumar@intel.com>; Li, Kevin Y <kevin.y.li@intel.com>; Zeng,
> Star <star.zeng@intel.com>
> Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> Remove CPU generation check
> 
> Situation: All the generations (including the internal generations not listed in
> SDM) we saw have MSR 13Ch available when CpuInfo-
> >CpuIdVersionInfoEcx.Bits.AESNI == 1.
> 
> Requirement: Reuse more code.
> 
> Could you help think the good method and even propose the patch for that?
> I am ok to any method to improve the code's reusability.
> Otherwise, we can only use function level override method ina
> CpuSpecificFeaturesLib.
>     Status = RegisterCpuFeature (
>                "AESNI",
>                NULL,                                         // Use core function
>                SpecificAesniSupport,                         // Override core function
>                NULL,                                         // Use core function
>                CPU_FEATURE_AESNI,
>                CPU_FEATURE_END
>                );
> 
> Thanks,
> Star
> > -----Original Message-----
> > From: Ni, Ray
> > Sent: Friday, May 17, 2019 9:04 AM
> > To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io;
> > lersek@redhat.com
> > Cc: Dong, Eric <eric.dong@intel.com>; Kumar, Chandana C
> > <chandana.c.kumar@intel.com>
> > Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> > Remove CPU generation check
> >
> > Star,
> > I think the discussion is about providing the evidence to support
> > removing the generation check.
> > Not just the benefit of that.
> >
> > Thanks,
> > Ray
> >
> > > -----Original Message-----
> > > From: Zeng, Star
> > > Sent: Thursday, May 16, 2019 10:52 PM
> > > To: devel@edk2.groups.io; lersek@redhat.com
> > > Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>;
> > > Kumar, Chandana C <chandana.c.kumar@intel.com>; Zeng, Star
> > > <star.zeng@intel.com>
> > > Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> > > Remove CPU generation check
> > >
> > > Laszlo,
> > >
> > > > -----Original Message-----
> > > > From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf
> > > > Of Laszlo Ersek
> > > > Sent: Thursday, May 16, 2019 9:06 PM
> > > > To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io
> > > > Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>;
> > > > Kumar, Chandana C <chandana.c.kumar@intel.com>
> > > > Subject: Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> > > > Remove CPU generation check
> > > >
> > > > Hi Star,
> > > >
> > > > On 05/16/19 12:33, Star Zeng wrote:
> > > > > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1679
> > > > >
> > > > > The checking to CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI is
> > > > > enough, the checking to CPU generation could be removed, then
> > > > > the code could be reused by more platforms.
> > > > >
> > > > > 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>
> > > > > Signed-off-by: Star Zeng <star.zeng@intel.com>
> > > > > ---
> > > > >  UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c | 12
> > > > > +++---------
> > > > >  1 file changed, 3 insertions(+), 9 deletions(-)
> > > > >
> > > > > diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > > b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > > index b79446ba3ca9..4a56eec1b267 100644
> > > > > --- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > > +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > > @@ -57,15 +57,9 @@ AesniSupport (
> > > > >    MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER
> > > *MsrFeatureConfig;
> > > > >
> > > > >    if (CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI == 1) {
> > > > > -    if (IS_SANDY_BRIDGE_PROCESSOR (CpuInfo->DisplayFamily,
> > CpuInfo-
> > > > >DisplayModel) ||
> > > > > -        IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > > > >DisplayModel) ||
> > > > > -        IS_XEON_5600_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > > > >DisplayModel) ||
> > > > > -        IS_XEON_E7_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > > > >DisplayModel) ||
> > > > > -        IS_XEON_PHI_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > > > >DisplayModel)) {
> > > > > -      MsrFeatureConfig =
> > > > (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > > > > -      ASSERT (MsrFeatureConfig != NULL);
> > > > > -      MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> > > > (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> > > > > -    }
> > > > > +    MsrFeatureConfig =
> > > > (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > > > > +    ASSERT (MsrFeatureConfig != NULL);
> > > > > +    MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> > > > > + (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> > > > >      return TRUE;
> > > > >    }
> > > > >    return FALSE;
> > > > >
> > > >
> > > > the patch and the bugzilla ticket claim that the AESNI bit's
> > > > presence in CPUID guarantees that MSR 0x13C is available.
> > >
> > > That is the case we met. The purpose of this patch is to make the
> > > code more usable.
> > >
> > > >
> > > > I don't see what guarantees this. According to the latest Intel
> > > > SDM Vol 4, which I just downloaded (335592-069US, January 2019),
> > > > MSR_FEATURE_CONFIG is available on the following (DisplayFamily,
> > > > DisplayModel) pairs:
> > > >
> > > > - 06_37H, 06_4AH, 06_4DH, 06_5AH, 06_5DH, 06_5CH, 06_7AH
> > > > - 06_25H, 06_2CH
> > > > - 06_2FH
> > > > - 06_2AH, 06_2DH
> > > > - 06_57H
> > >
> > > Yes, right.
> > >
> > > Let me show some examples for the generations not in the list above.
> > >
> > > 1. MSR 0x13C is available: our some internal generations are in this case.
> > > Without the patch, code needs to use function level override method
> > > in a CpuSpecificFeaturesLib.
> > >     Status = RegisterCpuFeature (
> > >                "AESNI",
> > >                NULL,                                         // Use core function
> > >                SpecificAesniSupport,                         // Override core function
> > >                NULL,                                         // Use core function
> > >                CPU_FEATURE_AESNI,
> > >                CPU_FEATURE_END
> > >                );
> > > With the patch, the function level override will be not needed. The
> > > benefit of this patch is here.
> > >
> > > 2. MSR 0x13C is not available: let's assume some other MSR will be
> > > available for the case.
> > > Without or with the patch, codes both need to use function level
> > > override method in a CpuSpecificFeaturesLib.
> > >     Status = RegisterCpuFeature (
> > >                "AESNI",
> > >                NULL,                                         // Use core function
> > >                SpecificAesniSupport,                         // Override core function
> > >                SpecificAesniInitialize,                         // Override core function
> > >                CPU_FEATURE_AESNI,
> > >                CPU_FEATURE_END
> > >                );
> > >
> > >
> > > Thanks,
> > > Star
> > >
> > > >
> > > > Which seems to indicate that at least *the approach* of the
> > > > original code -- i.e. the family/model checking -- is correct.
> > > > (It's possible that the family/model list has to be extended from
> > > > time to time, of
> > > > course.)
> > > >
> > > > Anyway, I don't intend to block this patch; OVMF does not use
> > > > CpuCommonFeaturesLib, so this change cannot regress it. I will let
> > > > other UefiCpuPkg reviewers decide about this patch.
> > > >
> > > > Thanks!
> > > > Laszlo
> > > >
> > > > 


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib: Remove CPU generation check
  2019-05-17 13:10         ` Ni, Ray
@ 2019-05-18  5:51           ` Zeng, Star
  0 siblings, 0 replies; 9+ messages in thread
From: Zeng, Star @ 2019-05-18  5:51 UTC (permalink / raw)
  To: Ni, Ray, devel@edk2.groups.io, lersek@redhat.com
  Cc: Dong, Eric, Kumar, Chandana C, Li, Kevin Y, Zeng, Star

Thanks for the understanding to all of you.


Star
> -----Original Message-----
> From: Ni, Ray
> Sent: Friday, May 17, 2019 9:11 PM
> To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io;
> lersek@redhat.com
> Cc: Dong, Eric <eric.dong@intel.com>; Kumar, Chandana C
> <chandana.c.kumar@intel.com>; Li, Kevin Y <kevin.y.li@intel.com>
> Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> Remove CPU generation check
> 
> Star,
> I understand the motivation of the change.
> 
> Given your statement that all processors you met follows the rule, and I
> know that you are currently working very actively on Intel processors,
> Reviewed-by: Ray Ni <ray.ni@intel.com>
> 
> > -----Original Message-----
> > From: Zeng, Star
> > Sent: Friday, May 17, 2019 11:05 AM
> > To: Ni, Ray <ray.ni@intel.com>; devel@edk2.groups.io;
> > lersek@redhat.com
> > Cc: Dong, Eric <eric.dong@intel.com>; Kumar, Chandana C
> > <chandana.c.kumar@intel.com>; Li, Kevin Y <kevin.y.li@intel.com>;
> > Zeng, Star <star.zeng@intel.com>
> > Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> > Remove CPU generation check
> >
> > Situation: All the generations (including the internal generations not
> > listed in
> > SDM) we saw have MSR 13Ch available when CpuInfo-
> > >CpuIdVersionInfoEcx.Bits.AESNI == 1.
> >
> > Requirement: Reuse more code.
> >
> > Could you help think the good method and even propose the patch for that?
> > I am ok to any method to improve the code's reusability.
> > Otherwise, we can only use function level override method ina
> > CpuSpecificFeaturesLib.
> >     Status = RegisterCpuFeature (
> >                "AESNI",
> >                NULL,                                         // Use core function
> >                SpecificAesniSupport,                         // Override core function
> >                NULL,                                         // Use core function
> >                CPU_FEATURE_AESNI,
> >                CPU_FEATURE_END
> >                );
> >
> > Thanks,
> > Star
> > > -----Original Message-----
> > > From: Ni, Ray
> > > Sent: Friday, May 17, 2019 9:04 AM
> > > To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io;
> > > lersek@redhat.com
> > > Cc: Dong, Eric <eric.dong@intel.com>; Kumar, Chandana C
> > > <chandana.c.kumar@intel.com>
> > > Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> > > Remove CPU generation check
> > >
> > > Star,
> > > I think the discussion is about providing the evidence to support
> > > removing the generation check.
> > > Not just the benefit of that.
> > >
> > > Thanks,
> > > Ray
> > >
> > > > -----Original Message-----
> > > > From: Zeng, Star
> > > > Sent: Thursday, May 16, 2019 10:52 PM
> > > > To: devel@edk2.groups.io; lersek@redhat.com
> > > > Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>;
> > > > Kumar, Chandana C <chandana.c.kumar@intel.com>; Zeng, Star
> > > > <star.zeng@intel.com>
> > > > Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg CpuCommonFeaturesLib:
> > > > Remove CPU generation check
> > > >
> > > > Laszlo,
> > > >
> > > > > -----Original Message-----
> > > > > From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On
> > > > > Behalf Of Laszlo Ersek
> > > > > Sent: Thursday, May 16, 2019 9:06 PM
> > > > > To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io
> > > > > Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray
> > > > > <ray.ni@intel.com>; Kumar, Chandana C
> > > > > <chandana.c.kumar@intel.com>
> > > > > Subject: Re: [edk2-devel] [PATCH] UefiCpuPkg
> CpuCommonFeaturesLib:
> > > > > Remove CPU generation check
> > > > >
> > > > > Hi Star,
> > > > >
> > > > > On 05/16/19 12:33, Star Zeng wrote:
> > > > > > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1679
> > > > > >
> > > > > > The checking to CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI is
> > > > > > enough, the checking to CPU generation could be removed, then
> > > > > > the code could be reused by more platforms.
> > > > > >
> > > > > > 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>
> > > > > > Signed-off-by: Star Zeng <star.zeng@intel.com>
> > > > > > ---
> > > > > >  UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c | 12
> > > > > > +++---------
> > > > > >  1 file changed, 3 insertions(+), 9 deletions(-)
> > > > > >
> > > > > > diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > > > b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > > > index b79446ba3ca9..4a56eec1b267 100644
> > > > > > --- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > > > +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/Aesni.c
> > > > > > @@ -57,15 +57,9 @@ AesniSupport (
> > > > > >    MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER
> > > > *MsrFeatureConfig;
> > > > > >
> > > > > >    if (CpuInfo->CpuIdVersionInfoEcx.Bits.AESNI == 1) {
> > > > > > -    if (IS_SANDY_BRIDGE_PROCESSOR (CpuInfo->DisplayFamily,
> > > CpuInfo-
> > > > > >DisplayModel) ||
> > > > > > -        IS_SILVERMONT_PROCESSOR (CpuInfo->DisplayFamily,
> CpuInfo-
> > > > > >DisplayModel) ||
> > > > > > -        IS_XEON_5600_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > > > > >DisplayModel) ||
> > > > > > -        IS_XEON_E7_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > > > > >DisplayModel) ||
> > > > > > -        IS_XEON_PHI_PROCESSOR (CpuInfo->DisplayFamily, CpuInfo-
> > > > > >DisplayModel)) {
> > > > > > -      MsrFeatureConfig =
> > > > > (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > > > > > -      ASSERT (MsrFeatureConfig != NULL);
> > > > > > -      MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> > > > > (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> > > > > > -    }
> > > > > > +    MsrFeatureConfig =
> > > > > (MSR_SANDY_BRIDGE_FEATURE_CONFIG_REGISTER *) ConfigData;
> > > > > > +    ASSERT (MsrFeatureConfig != NULL);
> > > > > > +    MsrFeatureConfig[ProcessorNumber].Uint64 = AsmReadMsr64
> > > > > > + (MSR_SANDY_BRIDGE_FEATURE_CONFIG);
> > > > > >      return TRUE;
> > > > > >    }
> > > > > >    return FALSE;
> > > > > >
> > > > >
> > > > > the patch and the bugzilla ticket claim that the AESNI bit's
> > > > > presence in CPUID guarantees that MSR 0x13C is available.
> > > >
> > > > That is the case we met. The purpose of this patch is to make the
> > > > code more usable.
> > > >
> > > > >
> > > > > I don't see what guarantees this. According to the latest Intel
> > > > > SDM Vol 4, which I just downloaded (335592-069US, January 2019),
> > > > > MSR_FEATURE_CONFIG is available on the following (DisplayFamily,
> > > > > DisplayModel) pairs:
> > > > >
> > > > > - 06_37H, 06_4AH, 06_4DH, 06_5AH, 06_5DH, 06_5CH, 06_7AH
> > > > > - 06_25H, 06_2CH
> > > > > - 06_2FH
> > > > > - 06_2AH, 06_2DH
> > > > > - 06_57H
> > > >
> > > > Yes, right.
> > > >
> > > > Let me show some examples for the generations not in the list above.
> > > >
> > > > 1. MSR 0x13C is available: our some internal generations are in this case.
> > > > Without the patch, code needs to use function level override
> > > > method in a CpuSpecificFeaturesLib.
> > > >     Status = RegisterCpuFeature (
> > > >                "AESNI",
> > > >                NULL,                                         // Use core function
> > > >                SpecificAesniSupport,                         // Override core function
> > > >                NULL,                                         // Use core function
> > > >                CPU_FEATURE_AESNI,
> > > >                CPU_FEATURE_END
> > > >                );
> > > > With the patch, the function level override will be not needed.
> > > > The benefit of this patch is here.
> > > >
> > > > 2. MSR 0x13C is not available: let's assume some other MSR will be
> > > > available for the case.
> > > > Without or with the patch, codes both need to use function level
> > > > override method in a CpuSpecificFeaturesLib.
> > > >     Status = RegisterCpuFeature (
> > > >                "AESNI",
> > > >                NULL,                                         // Use core function
> > > >                SpecificAesniSupport,                         // Override core function
> > > >                SpecificAesniInitialize,                         // Override core function
> > > >                CPU_FEATURE_AESNI,
> > > >                CPU_FEATURE_END
> > > >                );
> > > >
> > > >
> > > > Thanks,
> > > > Star
> > > >
> > > > >
> > > > > Which seems to indicate that at least *the approach* of the
> > > > > original code -- i.e. the family/model checking -- is correct.
> > > > > (It's possible that the family/model list has to be extended
> > > > > from time to time, of
> > > > > course.)
> > > > >
> > > > > Anyway, I don't intend to block this patch; OVMF does not use
> > > > > CpuCommonFeaturesLib, so this change cannot regress it. I will
> > > > > let other UefiCpuPkg reviewers decide about this patch.
> > > > >
> > > > > Thanks!
> > > > > Laszlo
> > > > >
> > > > > 


^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2019-05-18  5:51 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-05-16 10:33 [PATCH] UefiCpuPkg CpuCommonFeaturesLib: Remove CPU generation check Zeng, Star
2019-05-16 13:06 ` Laszlo Ersek
2019-05-16 14:51   ` [edk2-devel] " Zeng, Star
2019-05-17  1:01     ` Dong, Eric
2019-05-17  1:04     ` Ni, Ray
2019-05-17  3:05       ` Zeng, Star
2019-05-17 12:13         ` Laszlo Ersek
2019-05-17 13:10         ` Ni, Ray
2019-05-18  5:51           ` Zeng, Star

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