lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <f59f4cc3-6327-2f1e-dc32-03eeaffe1f54@amd.com>
Date: Mon, 27 May 2024 22:36:57 +0800
From: Xiaojian Du <xiaojidu@....com>
To: Dave Hansen <dave.hansen@...el.com>, Xiaojian Du <Xiaojian.Du@....com>,
 linux-kernel@...r.kernel.org, x86@...nel.org, linux-pm@...r.kernel.org
Cc: tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
 dave.hansen@...ux.intel.com, hpa@...or.com, daniel.sneddon@...ux.intel.com,
 jpoimboe@...nel.org, pawan.kumar.gupta@...ux.intel.com,
 sandipan.das@....com, kai.huang@...el.com, ray.huang@....com,
 rafael@...nel.org, Perry.Yuan@....com, gautham.shenoy@....com,
 Borislav.Petkov@....com, mario.limonciello@....com
Subject: Re: [PATCH v3 1/2] x86/cpufeatures: Add AMD FAST CPPC feature flag

Thanks Dave.

Because "CPPC" has existed in the "cpufeatures.h", thinking it will add 
duplicated line so I don't expand it.
Making this new flag hidden is to avoid causing user confusion about two 
"CPPC" flags.
This new feature flag is added to choose code branch, if not, it has to 
choose a ugly way and use CPU model ID.

Thanks,
Xiaojian


On 2024/5/24 0:31, Dave Hansen wrote:
> On 5/22/24 23:16, Xiaojian Du wrote:
>>   #define X86_FEATURE_BHI_CTRL		(21*32+ 2) /* "" BHI_DIS_S HW control available */
>>   #define X86_FEATURE_CLEAR_BHB_HW	(21*32+ 3) /* "" BHI_DIS_S HW control enabled */
>>   #define X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXIT (21*32+ 4) /* "" Clear branch history at vmexit using SW loop */
>> +#define X86_FEATURE_FAST_CPPC		(21*32 + 5) /* "" AMD Fast CPPC */
> It'd be nice to expand the CPPC acronym at least _once_.
>
> Also, this is used _once_ at boot and not exposed in /proc/cpuinfo.  Is
> it even worth defining an X86_FEATURE_ for it?

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ