From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.12]) (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 DBF1817836B for ; Tue, 17 Sep 2024 17:04:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726592663; cv=none; b=VUNdZbJK6/P41TPemgKe+jvFXTib2QI2ykLFmZk/h0elU9O4+SbNxPu4jrWDmomcRre5jwfFznBJRxdrDWK35QB66Y0lzyLQqIqDY8bvV1FEj5q/wOUbrFzZksXWAD65Q5f1SwNHS1gDpw/b1oeO9ZyLc9qq8E6fH2vAdFiEoZI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726592663; c=relaxed/simple; bh=77xdZMMNeD10kG0sUoHarDYtAaPCWc55oywuC/41nX8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jpG4An1ysBFQqNLltLoMz8cFJNQe7DADp/OfgmbopMPmK6p2VZOcbElpSrjeWwPCRzV4PKWJVIOggymsS+qPbutM6JlZd50HRBzgJjrwi6yempcfml2xCkg78Vo0Y7csoQcPWQz12ntpem69KBheLbzq9g6bojWHQjQ4M+mpWnY= 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=JkX4isUh; arc=none smtp.client-ip=192.198.163.12 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="JkX4isUh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1726592662; x=1758128662; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=77xdZMMNeD10kG0sUoHarDYtAaPCWc55oywuC/41nX8=; b=JkX4isUhTnnxrCkwja9KPfK4x3jK5PO04gXJafMYOJA0ve9e4G5mQqfo Kyu/GMowE5jAKG7/4iKk5VRXjJP3ASPskBsk4bhK1Y9fv+hwnMuUfLZJf QM8ENTflDyfzw3wG6NK3lsl8CBGITV3xDEYlVNv6X6ijYMtD9V8GtI/VG XTfsLboRuvfg8X0at8cZOhwvfDGiHO7OBM78LTEgbwD7vLFjDPosiMaxz bTKPlvyK37r/35zCqnAsrf2UTc5R5kH/9xEs/70B4kgi/JABAYlbS1CG8 7E64/sK/AFtrAoXjRiJsxFE961KH2GHukuuUhHWlEDmcXxqRs9NslzHuh g==; X-CSE-ConnectionGUID: NoBASW5DQ9KlhpajuMni8A== X-CSE-MsgGUID: zsCPXaFJRZeRUGKK+C1+PA== X-IronPort-AV: E=McAfee;i="6700,10204,11198"; a="29360125" X-IronPort-AV: E=Sophos;i="6.10,235,1719903600"; d="scan'208";a="29360125" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Sep 2024 10:04:21 -0700 X-CSE-ConnectionGUID: hwwG5ihNSQacVD0WkDzOgQ== X-CSE-MsgGUID: T1kXxPWvQuq4/U2BVdeELg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,235,1719903600"; d="scan'208";a="73612593" Received: from paragpar-mobl1.amr.corp.intel.com (HELO desk) ([10.125.147.172]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Sep 2024 10:04:20 -0700 Date: Tue, 17 Sep 2024 10:04:07 -0700 From: Pawan Gupta To: David Kaplan Cc: Thomas Gleixner , Borislav Petkov , Peter Zijlstra , Josh Poimboeuf , Ingo Molnar , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 00/34] x86/bugs: Attack vector controls Message-ID: <20240917170407.jxtpb75iru3qg74c@desk> References: <20240912190857.235849-1-david.kaplan@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240912190857.235849-1-david.kaplan@amd.com> On Thu, Sep 12, 2024 at 02:08:23PM -0500, David Kaplan wrote: > The rest of the patches define new "attack vector" command line options > to make it easier to select appropriate mitigations based on the usage > of the system. While many users may not be intimately familiar with the > details of these CPU vulnerabilities, they are likely better able to > understand the intended usage of their system. As a result, unneeded > mitigations may be disabled, allowing users to recoup more performance. How much performance improvement are you seeing with each of the attack vector? There aren't many vulnerabilities that only affect a single attack vector. So, selecting to mitigate single attack vector mitigates a lot more than that. We may be able to get better performance improvement by adding vector-based switches at the mitigation points. And only enable them if user asked for it.