linux-kernel - Re: [PATCH v15 12/34] fs/resctrl: Introduce mbm_cntr_cfg to track assignable counters per domain

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: <684128bd-282d-401b-a94a-69318bcc74a4@intel.com>
Date: Thu, 17 Jul 2025 11:46:52 -0700
From: Reinette Chatre <reinette.chatre@...el.com>
To: Babu Moger <babu.moger@....com>, <corbet@....net>, <tony.luck@...el.com>,
	<james.morse@....com>, <tglx@...utronix.de>, <mingo@...hat.com>,
	<bp@...en8.de>, <dave.hansen@...ux.intel.com>
CC: <Dave.Martin@....com>, <x86@...nel.org>, <hpa@...or.com>,
	<akpm@...ux-foundation.org>, <paulmck@...nel.org>, <rostedt@...dmis.org>,
	<Neeraj.Upadhyay@....com>, <david@...hat.com>, <arnd@...db.de>,
	<fvdl@...gle.com>, <seanjc@...gle.com>, <jpoimboe@...nel.org>,
	<pawan.kumar.gupta@...ux.intel.com>, <xin@...or.com>,
	<manali.shukla@....com>, <tao1.su@...ux.intel.com>, <sohil.mehta@...el.com>,
	<kai.huang@...el.com>, <xiaoyao.li@...el.com>, <peterz@...radead.org>,
	<xin3.li@...el.com>, <kan.liang@...ux.intel.com>,
	<mario.limonciello@....com>, <thomas.lendacky@....com>, <perry.yuan@....com>,
	<gautham.shenoy@....com>, <chang.seok.bae@...el.com>,
	<linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<peternewman@...gle.com>, <eranian@...gle.com>
Subject: Re: [PATCH v15 12/34] fs/resctrl: Introduce mbm_cntr_cfg to track
 assignable counters per domain

Hi Babu,

On 7/8/25 3:17 PM, Babu Moger wrote:
> The "mbm_event" counter assignment mode allows users to assign a hardware
> counter to an RMID, event pair and monitor bandwidth usage as long as it is
> assigned.  The hardware continues to track the assigned counter until it is
> explicitly unassigned by the user. Counters are assigned/unassigned at
> monitoring domain level.
> 
> Manage a monitoring domain's hardware counters using a per monitoring
> domain array of struct mbm_cntr_cfg that is indexed by the hardware
> counter ID. A hardware counter's configuration contains the MBM event
> ID and points to the monitoring group that it is assigned to, with a NULL
> pointer meaning that the hardware counter is available for assignment.
> 
> There is no direct way to determine which hardware counters are assigned
> to a particular monitoring group. Check every entry of every hardware
> counter configuration array in every monitoring domain to query which
> MBM events of a monitoring group is tracked by hardware. Such queries are
> acceptable because of a very small number of assignable counters (32
> to 64).
> 
> Suggested-by: Peter Newman <peternewman@...gle.com>
> Signed-off-by: Babu Moger <babu.moger@....com>
> ---

Reviewed-by: Reinette Chatre <reinette.chatre@...el.com>

Reinette