From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92C4FC43215 for ; Fri, 15 Nov 2019 06:23:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A2C120637 for ; Fri, 15 Nov 2019 06:23:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573799037; bh=k/QTvKQ7CL52EtvqmQq+zWJX9EG7E24ynNVmGRIe72w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FpLLcBMWa+UE4+AxCfVLWZZHx3LkoTKQsg3ygPpBWrf2CrKHWuNk6laCniGODeuuU 09YK7rXjLFXm4dzW5VEh4aDYo60PN1bV2Uy+8iromYyOGepPLaU8idYLNeucj5/E18 6yucg20qw14g+4mozTiKY3bt7+JuY+Nq12QY4DN4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727573AbfKOGWG (ORCPT ); Fri, 15 Nov 2019 01:22:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:51156 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727550AbfKOGWB (ORCPT ); Fri, 15 Nov 2019 01:22:01 -0500 Received: from localhost (unknown [104.132.150.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B61B42073C; Fri, 15 Nov 2019 06:22:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573798921; bh=k/QTvKQ7CL52EtvqmQq+zWJX9EG7E24ynNVmGRIe72w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=18afwdj6kFztacoBFVH1y2nmRLO0hNRKuV3QCoDHV2X73wfs2GZqILybfR74Pso/S ec94AV5WCHpWYEjxZPu2F2YWqaMR8Z1kmkrUGXfpr6P2cJqawE9ZgYjSopt59we1F+ itISkSwKR4tQFtOa5HqpBIcmUqWJKc4YCqcSNtoU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pawan Gupta , Borislav Petkov , Thomas Gleixner , Tony Luck , Josh Poimboeuf , Ben Hutchings Subject: [PATCH 4.9 12/31] x86/tsx: Add "auto" option to the tsx= cmdline parameter Date: Fri, 15 Nov 2019 14:20:41 +0800 Message-Id: <20191115062014.685532405@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191115062009.813108457@linuxfoundation.org> References: <20191115062009.813108457@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Pawan Gupta commit 7531a3596e3272d1f6841e0d601a614555dc6b65 upstream. Platforms which are not affected by X86_BUG_TAA may want the TSX feature enabled. Add "auto" option to the TSX cmdline parameter. When tsx=auto disable TSX when X86_BUG_TAA is present, otherwise enable TSX. More details on X86_BUG_TAA can be found here: https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html [ bp: Extend the arg buffer to accommodate "auto\0". ] Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Reviewed-by: Tony Luck Reviewed-by: Josh Poimboeuf [bwh: Backported to 4.9: adjust filename] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- Documentation/kernel-parameters.txt | 3 +++ arch/x86/kernel/cpu/tsx.c | 7 ++++++- 2 files changed, 9 insertions(+), 1 deletion(-) --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -4537,6 +4537,9 @@ bytes respectively. Such letter suffixes update. This new MSR allows for the reliable deactivation of the TSX functionality.) + auto - Disable TSX if X86_BUG_TAA is present, + otherwise enable TSX on the system. + Not specifying this option is equivalent to tsx=off. See Documentation/hw-vuln/tsx_async_abort.rst --- a/arch/x86/kernel/cpu/tsx.c +++ b/arch/x86/kernel/cpu/tsx.c @@ -75,7 +75,7 @@ static bool __init tsx_ctrl_is_supported void __init tsx_init(void) { - char arg[4] = {}; + char arg[5] = {}; int ret; if (!tsx_ctrl_is_supported()) @@ -87,6 +87,11 @@ void __init tsx_init(void) tsx_ctrl_state = TSX_CTRL_ENABLE; } else if (!strcmp(arg, "off")) { tsx_ctrl_state = TSX_CTRL_DISABLE; + } else if (!strcmp(arg, "auto")) { + if (boot_cpu_has_bug(X86_BUG_TAA)) + tsx_ctrl_state = TSX_CTRL_DISABLE; + else + tsx_ctrl_state = TSX_CTRL_ENABLE; } else { tsx_ctrl_state = TSX_CTRL_DISABLE; pr_err("tsx: invalid option, defaulting to off\n");