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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4AD9AEB64D9 for ; Thu, 15 Jun 2023 17:32:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236706AbjFORcd (ORCPT ); Thu, 15 Jun 2023 13:32:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230167AbjFORc2 (ORCPT ); Thu, 15 Jun 2023 13:32:28 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 559101FDD for ; Thu, 15 Jun 2023 10:32:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1686850347; x=1718386347; h=from:to:cc:subject:references:date:in-reply-to: message-id:mime-version; bh=gj1PE8jgcTAjvU5QpELZ2BVDX+vgouCIrJw6XJgXAGI=; b=GqFT9P00Zbh0a2/lpaNRpar0aXHALKvhhx6hveRRBeOtrL+PVeEfWY1B M5cCX1UPlUJLQF6uJuMiL3AoGgIlMuSmDVVE3RZ1gCGMyOQNNV5Y75GfQ t+vn3olJLL8c8zJL2VATcnmK8JTTme5VPaPWNE6/sAdXgexC4pm6fNRx3 B5s+B/LhkXb8MzpgGyLE4PeIWawGUEvx+xjIXia4Mjp1qv7LSulf4OHcd 9HS+7fgptj7b8Cnq+Quh6iM52qu39UyFbSohXy8fKpPw3tMgdrYigRiXZ SOkmEozxPP78Npv3AZBVgQ9h9crlIr/uyZONw8rse2TOvYEhciDsbibEI g==; X-IronPort-AV: E=McAfee;i="6600,9927,10742"; a="362402750" X-IronPort-AV: E=Sophos;i="6.00,245,1681196400"; d="scan'208";a="362402750" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jun 2023 10:21:55 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10742"; a="706764961" X-IronPort-AV: E=Sophos;i="6.00,245,1681196400"; d="scan'208";a="706764961" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.54.38.190]) by orsmga007.jf.intel.com with ESMTP; 15 Jun 2023 10:21:55 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id 86E65302A4D; Thu, 15 Jun 2023 10:21:55 -0700 (PDT) From: Andi Kleen To: Breno Leitao Cc: pawan.kumar.gupta@linux.intel.com, jpoimboe@kernel.org, peterz@infradead.org, tglx@linutronix.de, bp@alien8.de, leit@fb.com, hpa@zytor.com, x86@kernel.org, mingo@redhat.com, dave.hansen@linux.intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] x86/bugs: Break down mitigations configurations References: <20230615164417.3588162-1-leitao@debian.org> Date: Thu, 15 Jun 2023 10:21:55 -0700 In-Reply-To: <20230615164417.3588162-1-leitao@debian.org> (Breno Leitao's message of "Thu, 15 Jun 2023 09:44:11 -0700") Message-ID: <87352shc98.fsf@linux.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Breno Leitao writes: > There is no way to compile a kernel today with some of the speculative > mitigations disabled. Even if the kernel has > CONFIG_SPECULATION_MITIGATIONS=n, some Intel mitigations, such as MDS, TAA, > MMIO are still enabled and can only be disabled using a kernel parameter. > > This patchset creates a way to choose what to enable or disable, and, > get the mitigations disable if CONFIG_SPECULATION_MITIGATIONS is not > set, as the rest of other mitigations. > > Also, we want to print a warning message letting users know that these > mitigations are disabled. > > This is a follow up to this discussion: https://lkml.org/lkml/2023/6/12/798 > Isn't this all roughly equivalent to CONFIG_CMDLINE="mitigations=..." ? -Andi