From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) (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 CF338146019; Tue, 24 Sep 2024 22:32:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727217128; cv=none; b=nlNMXDxFs8UkLn/z/NlTlwp9IhLr3834+ndHFxIRcxGh2XA4LLY88NHo5duSw6b+AxaexkAymZEohg37kRfCxtk+mQB0LlDOWOQ5POT6qn1jbJJ7ViEZRsObkJvjGq2gtGANlsANtDQGi7svWueQO3wWmQlaQBMQWdnx7ge1KU4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727217128; c=relaxed/simple; bh=JHP0kucEu5cNf6IEZdyNVnwiW4oeLVhE0jcwDKFRP2g=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=YXDIfoXAt6DVBqAD8GZb30YaKuEMRXOeKpWPcNEfG0lpQT2UgqutRLQNhrLcjAQVMV/CiQ6fQnNcupufuwC47gFmR1z2K+5Pr4hYY9hl+ycFuLy5ZCADUexlh8mOWNEKS3XKFouafK+3GNAufeY7fyfUV/9zh8M6Ujv9Ms8Wmsg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=C39WWmGg; arc=none smtp.client-ip=192.198.163.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="C39WWmGg" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1727217127; x=1758753127; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=JHP0kucEu5cNf6IEZdyNVnwiW4oeLVhE0jcwDKFRP2g=; b=C39WWmGgrLBDQfDO86yvaq69TCdxY9DqS3NCdVYheKSZP6N3HWPm0Wga hdta2jDfROH/LRUC+LcC34JNXgzxwG6i3oEKvoKKj0RqUOol+ZE54UmnJ YL3j52lUv6WycNAsjJC+5PWL0+cpRH+GiJ0CtKfURnsEtUwvwGxQPZ2IX CnYxdIbhxhkOwxELlit4xWQEEL4ILhO0DEFdmNdmLZtwcPhSFWKxH3mB6 4qzHP9dSvsvgDnnOE1bOU8HSPXEJkfnBaRVXDgxqdo5oDjwDKZ7RKhOUq PzfYiKrWaNE8zk31g3+RD/g/Qb/Ymv9LaXa19r9bh2RFmOW+AHZjOGlDB Q==; X-CSE-ConnectionGUID: swIGsEUwQ5+mAS+BvieOtg== X-CSE-MsgGUID: aIVcd1IXQf6CVP8kx+XKyQ== X-IronPort-AV: E=McAfee;i="6700,10204,11205"; a="36908054" X-IronPort-AV: E=Sophos;i="6.10,255,1719903600"; d="scan'208";a="36908054" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Sep 2024 15:31:54 -0700 X-CSE-ConnectionGUID: YWmSlBm4T3+2j1quPKRsHg== X-CSE-MsgGUID: dx6f5LTfSGeRmGXbU44K1w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,255,1719903600"; d="scan'208";a="102384786" Received: from laijusti-mobl.amr.corp.intel.com (HELO dsneddon-desk.sneddon.lan) ([10.125.17.198]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Sep 2024 15:31:52 -0700 From: Daniel Sneddon To: Jonathan Corbet , Thomas Gleixner , Borislav Petkov , Peter Zijlstra , Josh Poimboeuf , Ingo Molnar , Dave Hansen , x86@kernel.org Cc: hpa@zytor.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, pawan.kumar.gupta@linux.intel.com Subject: [PATCH 2/6] x86/bugs: Remove MDS command line Date: Tue, 24 Sep 2024 15:31:36 -0700 Message-Id: <20240924223140.1054918-3-daniel.sneddon@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240924223140.1054918-1-daniel.sneddon@linux.intel.com> References: <20240924223140.1054918-1-daniel.sneddon@linux.intel.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Remove MDS command line option since it can be set using the common clar_cpu_buffers parameter. Signed-off-by: Daniel Sneddon --- .../admin-guide/kernel-parameters.txt | 32 ------------------- arch/x86/kernel/cpu/bugs.c | 21 ------------ 2 files changed, 53 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 66b567c4dce5..2753a1e51da5 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3231,38 +3231,6 @@ Format: , Specifies range of consoles to be captured by the MDA. - mds= [X86,INTEL,EARLY] - Control mitigation for the Micro-architectural Data - Sampling (MDS) vulnerability. - - Certain CPUs are vulnerable to an exploit against CPU - internal buffers which can forward information to a - disclosure gadget under certain conditions. - - In vulnerable processors, the speculatively - forwarded data can be used in a cache side channel - attack, to access data to which the attacker does - not have direct access. - - This parameter controls the MDS mitigation. The - options are: - - full - Enable MDS mitigation on vulnerable CPUs - full,nosmt - Enable MDS mitigation and disable - SMT on vulnerable CPUs - off - Unconditionally disable MDS mitigation - - On TAA-affected machines, mds=off can be prevented by - an active TAA mitigation as both vulnerabilities are - mitigated with the same mechanism so in order to disable - this mitigation, you need to specify tsx_async_abort=off - too. - - Not specifying this option is equivalent to - mds=full. - - For details see: Documentation/admin-guide/hw-vuln/mds.rst - mem=nn[KMG] [HEXAGON,EARLY] Set the memory size. Must be specified, otherwise memory size will be 0. diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index b3c9e1eede12..ed5524bc3ee4 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -261,27 +261,6 @@ static void __init mds_select_mitigation(void) } } -static int __init mds_cmdline(char *str) -{ - if (!boot_cpu_has_bug(X86_BUG_MDS)) - return 0; - - if (!str) - return -EINVAL; - - if (!strcmp(str, "off")) - mds_mitigation = MDS_MITIGATION_OFF; - else if (!strcmp(str, "full")) - mds_mitigation = MDS_MITIGATION_FULL; - else if (!strcmp(str, "full,nosmt")) { - mds_mitigation = MDS_MITIGATION_FULL; - mds_nosmt = true; - } - - return 0; -} -early_param("mds", mds_cmdline); - #undef pr_fmt #define pr_fmt(fmt) "TAA: " fmt -- 2.25.1