From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8D606480DFF for ; Wed, 19 Aug 2026 16:13:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787156017; cv=none; b=jULl9Wagik+1YGqOZZ9Wt5PFyJXIs0CZLbLyGCGQsFFC3xvMtQA50EUPB5vVsOihYVZtwSBvX7h3kwz5rnMQLIOk3LVgKlUIpoyT+D78aMsdOJFr9mNaGqcAwfeCr35q/JYQldFPY/WC2xJ/f0Ty/5vH8DF8POe9ddr0IhynCEM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787156017; c=relaxed/simple; bh=WuDNhkqq00kjVqYmDtHZU0GQSxxyzh5NoYhjctJowrU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fZbur8CM8PNyzKH2lmGhih9cCOrUFAXRv2E7rMjDIElgpzexBhFUMdFIvGMbRY8DgPgeq+DCZhAVf/f76cXEHUjnX7CvHmRZxoU5rxvaU5ihGN8NyI2y4wkMf2YKvGle3RJAuQnXPzJ9oDwNdu9pJ+nnAgBvTTsqTxNcvJVnnl4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=DzpvWFlk; arc=none smtp.client-ip=198.175.65.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="DzpvWFlk" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1787156015; x=1818692015; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=WuDNhkqq00kjVqYmDtHZU0GQSxxyzh5NoYhjctJowrU=; b=DzpvWFlka5D0z8q3KFaWptALtwSD4on9HpMzFH/CAgrGs8+/cw/RrjZU psBkLMU/7j2mbg5pFkFFrZW5UtnG68WPQvQi6F/eOoatYtP8RuC4HV39Z tKQ+17NVevF02atVaDMks7yPhNm5HFvgCcluMjs16znGM8mYVnQtAFDgG ckWLrOQcUIYIs/S1sF8Y3duB+5M+9m6YQxVXvGOfb1oSEBRjEIwzqcbT3 tbRm5qIAZWIW/YLziBR3PL1Vmr8TRoKFjEY5Q0eNTJ27VB0VYt7yG/zmP tScwkkoc4f89Q8wojUN1RN7SPQ0Rqpu2OULDotNxfMielPWymswXrFa82 g==; X-CSE-ConnectionGUID: 7qjmY5UKRlipHKItelBmwQ== X-CSE-MsgGUID: DOXt5AabQGG27eSbfPkwNg== X-IronPort-AV: E=McAfee;i="6800,10657,11880"; a="87598047" X-IronPort-AV: E=Sophos;i="6.25,231,1779174000"; d="scan'208";a="87598047" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Aug 2026 09:13:33 -0700 X-CSE-ConnectionGUID: TpOGlf1RQ+G1990Ts1zCpw== X-CSE-MsgGUID: p29TT35EQbWv46FuIQDk3A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,231,1779174000"; d="scan'208";a="290391841" Received: from rodrigoa-mobl1.amr.corp.intel.com (HELO agluck-desk3.intel.com) ([10.124.221.31]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Aug 2026 09:13:33 -0700 From: Tony Luck To: Fenghua Yu , Reinette Chatre , Maciej Wieczor-Retman , Peter Newman , James Morse , Babu Moger , Drew Fustini , Dave Martin , Chen Yu , x86@kernel.org Cc: linux-kernel@vger.kernel.org, patches@lists.linux.dev, Tony Luck Subject: [RFC PATCH 1/4] x86/resctrl: Check if monitoring features are enabled Date: Wed, 19 Aug 2026 09:13:19 -0700 Message-ID: <20260819161323.11587-2-tony.luck@intel.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260819161323.11587-1-tony.luck@intel.com> References: <20260819161323.11587-1-tony.luck@intel.com> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Both Intel and AMD manuals say that software must first check CPUID(0x7,0x0).EBX[12] to see if any monitoring features are enabled before checking for specific features enabled in subleaves. Add the check for X86_FEATURE_CQM. Fixes: cbc82b172638 ("x86: Add support for Intel Cache QoS Monitoring (CQM) detection") Signed-off-by: Tony Luck --- arch/x86/kernel/cpu/resctrl/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 55214d6fdc49..2677b8a6c15b 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -968,6 +968,9 @@ static __init bool get_rdt_mon_resources(void) struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; bool ret = false; + if (!cpu_feature_enabled(X86_FEATURE_CQM)) + return false; + if (rdt_cpu_has(X86_FEATURE_CQM_OCCUP_LLC)) { resctrl_enable_mon_event(QOS_L3_OCCUP_EVENT_ID, false, 0, NULL); ret = true; -- 2.55.0