From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (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 8511E4D2ED3 for ; Wed, 16 Sep 2026 23:13:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789600414; cv=none; b=nwn6pi+HoI8mbkAjsepQTHiPunobdRUXE63gEAAYwoUpaTTQsXNUcH+L93u3UT+QL6n5TbkLkPUBdOsL2Q9CpeNBaXXlQbZCKOHOwS3ovyGmWMQ+VjGFHtxRuAeP3a3Omag503KuN8ByYbntXcOikNnUNJqd+DvSTBmTG7M8Crc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789600414; c=relaxed/simple; bh=SJWp1RNmkTVmRTX4ajftJQ6TmgZ+7cQho1eSP7VnGvs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BUbDIY7hLIeCKK0Uhkbg3Iz5LVi1ghDJmvAzEJ+1NKTlmoSFxCDz4z4SazdKJ7oUJFh8ZAk8cPVEhYWVBfTYraf6oz+rKHi0SHtlB4tq5YLGiJmGmuiVFmbNRK6pO3qS/K3PaIRfgjsZ2/pZqz6w3YZ7Ej9OHqFF8dMhBnS8iRo= 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=U5kLOWwl; arc=none smtp.client-ip=198.175.65.14 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="U5kLOWwl" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1789600413; x=1821136413; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=SJWp1RNmkTVmRTX4ajftJQ6TmgZ+7cQho1eSP7VnGvs=; b=U5kLOWwlQbYXROA+vKaQbPJPi7BYs6WFif2aBlFQendRK3CTcXGMx87W vhAwqrlyKwAqTf/v7jLnW4S9Xon6sLm7Thk17lfherCfKig8xahYH+7tH zjflM+KhpVrheIzkmZwclHH6uLVzoLNuYbQuG0T9XhmHvglERtJSzJWIA aTqEupmFl2lzjlSFK2T2bAJGyiaUC6qlTE+O2HWhiAYg/VhO/xly4Ay2I fgrY/BA+PBR5zEVouRU9mr50UO57dQIVetPqHFD5K5bEv7DYz6xgZywlH wKSjvkIRT6AhA6D8795eh5hnoT3z5VFftUs+q9T129EFG189cr9iGggs4 w==; X-CSE-ConnectionGUID: XZmMl6dAQVqYZkcI1rQG7g== X-CSE-MsgGUID: StmAkTqMRYCmOHU9tQD49g== X-IronPort-AV: E=McAfee;i="6800,10657,11905"; a="93861326" X-IronPort-AV: E=Sophos;i="6.27,103,1787036400"; d="scan'208";a="93861326" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2026 16:13:31 -0700 X-CSE-ConnectionGUID: 594Vl3cFQtyRZbDeFnEcHw== X-CSE-MsgGUID: lusfiszMQZCUjSAD4fsGZw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,103,1787036400"; d="scan'208";a="277231425" Received: from khuang2-desk.gar.corp.intel.com (HELO agluck-desk3.home.arpa) ([10.124.223.219]) by orviesa004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2026 16:13:31 -0700 From: Tony Luck To: Fenghua Yu , Reinette Chatre , Maciej Wieczor-Retman , Peter Newman , James Morse , Babu Moger , Drew Fustini , Dave Martin , Chen Yu , David E Box , x86@kernel.org Cc: Christoph Hellwig , linux-kernel@vger.kernel.org, patches@lists.linux.dev, Tony Luck Subject: [PATCH v12 02/25] x86/resctrl: Check if monitoring features are supported Date: Wed, 16 Sep 2026 16:12:57 -0700 Message-ID: <20260916231320.14502-3-tony.luck@intel.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260916231320.14502-1-tony.luck@intel.com> References: <20260916231320.14502-1-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] (Linux: X86_FEATURE_CQM) to see if any monitoring features are supported before checking for specific features supported in subleaves. Each of the L3-based monitoring features is further gated by CPUID(0xF,0x0).EDX[1] (Linux: X86_FEATURE_CQM_LLC). Add checks for these feature bits. Fixes: cbc82b172638 ("x86: Add support for Intel Cache QoS Monitoring (CQM) detection") Signed-off-by: Tony Luck --- v12: Revert X86_FEATURE name changes. Invert the test for X86_FEATURE_CQM_LLC to avoid adding extra indentation churn and keep call to rdt_get_l3_mon_config in the X86_FEATURE_CQM_LLC code path. --- arch/x86/kernel/cpu/resctrl/core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 55214d6fdc49..34ca3c7cc046 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -968,6 +968,14 @@ static __init bool get_rdt_mon_resources(void) struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; bool ret = false; + /* Any monitoring at all? */ + if (!cpu_feature_enabled(X86_FEATURE_CQM)) + return false; + + /* Any of the L3 monitoring features? */ + if (!cpu_feature_enabled(X86_FEATURE_CQM_LLC)) + 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