linux-kernel - Re: [PATCH v17 22/33] x86/resctrl: Implement resctrl_arch_reset_cntr() and resctrl_arch_cntr

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: <811782dd-3240-4af1-a42b-8a6cf49739e5@intel.com>
Date: Tue, 2 Sep 2025 19:34:07 -0700
From: Reinette Chatre <reinette.chatre@...el.com>
To: Babu Moger <babu.moger@....com>, <corbet@....net>, <tony.luck@...el.com>,
	<tglx@...utronix.de>, <mingo@...hat.com>, <bp@...en8.de>,
	<dave.hansen@...ux.intel.com>
CC: <Dave.Martin@....com>, <james.morse@....com>, <x86@...nel.org>,
	<hpa@...or.com>, <akpm@...ux-foundation.org>, <rostedt@...dmis.org>,
	<paulmck@...nel.org>, <pawan.kumar.gupta@...ux.intel.com>, <kees@...nel.org>,
	<arnd@...db.de>, <fvdl@...gle.com>, <seanjc@...gle.com>,
	<thomas.lendacky@....com>, <yosry.ahmed@...ux.dev>, <xin@...or.com>,
	<sohil.mehta@...el.com>, <kai.huang@...el.com>, <xiaoyao.li@...el.com>,
	<peterz@...radead.org>, <mario.limonciello@....com>, <xin3.li@...el.com>,
	<perry.yuan@....com>, <chang.seok.bae@...el.com>,
	<linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<peternewman@...gle.com>, <eranian@...gle.com>, <gautham.shenoy@....com>
Subject: Re: [PATCH v17 22/33] x86/resctrl: Implement
 resctrl_arch_reset_cntr() and resctrl_arch_cntr_read()

Hi Babu,

On 8/14/25 7:25 PM, Babu Moger wrote:
> System software reads resctrl event data for a particular resource by
> writing the RMID and Event Identifier (EvtID) to the QM_EVTSEL register and
> then reading the event data from the QM_CTR register.
> 
> In ABMC mode, the event data of a specific counter ID is read by setting
> the following fields: QM_EVTSEL.ExtendedEvtID = 1, QM_EVTSEL.EvtID =
> L3CacheABMC (=1) and setting QM_EVTSEL.RMID to the desired counter ID.
> Reading the QM_CTR then returns the contents of the specified counter ID.
> RMID_VAL_ERROR bit is set if the counter configuration is invalid, or
> if an invalid counter ID is set in the QM_EVTSEL.RMID field.
> RMID_VAL_UNAVAIL bit is set if the counter data is unavailable.
> 
> Introduce resctrl_arch_reset_cntr() and resctrl_arch_cntr_read() to reset
> and read event data for a specific counter.
> 
> Signed-off-by: Babu Moger <babu.moger@....com>
> ---

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

Reinette