linux-kernel - Re: [PATCH v11 06/23] x86/resctrl: Add support to enable/disable AMD ABMC feature

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: <797bb878-8049-47dc-b1c9-193158b9ba45@arm.com>
Date: Fri, 21 Feb 2025 18:05:15 +0000
From: James Morse <james.morse@....com>
To: Babu Moger <babu.moger@....com>, corbet@....net,
 reinette.chatre@...el.com, tglx@...utronix.de, mingo@...hat.com,
 bp@...en8.de, dave.hansen@...ux.intel.com, tony.luck@...el.com,
 peternewman@...gle.com
Cc: fenghua.yu@...el.com, x86@...nel.org, hpa@...or.com, paulmck@...nel.org,
 akpm@...ux-foundation.org, thuth@...hat.com, rostedt@...dmis.org,
 xiongwei.song@...driver.com, pawan.kumar.gupta@...ux.intel.com,
 daniel.sneddon@...ux.intel.com, jpoimboe@...nel.org, perry.yuan@....com,
 sandipan.das@....com, kai.huang@...el.com, xiaoyao.li@...el.com,
 seanjc@...gle.com, xin3.li@...el.com, andrew.cooper3@...rix.com,
 ebiggers@...gle.com, mario.limonciello@....com, tan.shaopeng@...itsu.com,
 linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
 maciej.wieczor-retman@...el.com, eranian@...gle.com
Subject: Re: [PATCH v11 06/23] x86/resctrl: Add support to enable/disable AMD
 ABMC feature

Hi Babu,

On 22/01/2025 20:20, Babu Moger wrote:
> Add the functionality to enable/disable AMD ABMC feature.
> 
> AMD ABMC feature is enabled by setting enabled bit(0) in MSR
> L3_QOS_EXT_CFG. When the state of ABMC is changed, the MSR needs
> to be updated on all the logical processors in the QOS Domain.
> 
> Hardware counters will reset when ABMC state is changed.
> 
> The ABMC feature details are documented in APM listed below [1].
> [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming
> Publication # 24593 Revision 3.41 section 19.3.3.3 Assignable Bandwidth
> Monitoring (ABMC).


> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
> index 05358e78147b..ca69f2e0909f 100644
> --- a/arch/x86/kernel/cpu/resctrl/internal.h
> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
> @@ -658,4 +663,6 @@ void resctrl_file_fflags_init(const char *config, unsigned long fflags);
>  void rdt_staged_configs_clear(void);
>  bool closid_allocated(unsigned int closid);
>  int resctrl_find_cleanest_closid(void);
> +int resctrl_arch_mbm_cntr_assign_set(struct rdt_resource *r, bool enable);
> +bool resctrl_arch_mbm_cntr_assign_enabled(struct rdt_resource *r);
>  #endif /* _ASM_X86_RESCTRL_INTERNAL_H */

A minor nit - but could these be added to include/linux/resctrl.h instead?
This is where they need to end up after the arch/fs split, and its harmless to do it from
the beginning.


Thanks,

James