Received: by 2002:a05:6a10:a841:0:0:0:0 with SMTP id d1csp54558pxy; Wed, 21 Apr 2021 18:18:40 -0700 (PDT) X-Google-Smtp-Source: ABdhPJw/05/Bmrmv+mkb9DwB/q9wcWjEKOqqJtddxVDziYegk0VOf5lAHeaOBovUEN5F2aZin+ns X-Received: by 2002:a17:90b:1647:: with SMTP id il7mr13791099pjb.132.1619054320204; Wed, 21 Apr 2021 18:18:40 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1619054320; cv=none; d=google.com; s=arc-20160816; b=QfLtKdp9pgGeYy0vGTa9vidPo9l5MsKlfGus0CS31CmrcDPKsfPrbzhBB5dyxNoxWl HokAR+l21nR+avugxsmncuAAAbUJBFptsw94e3cNdvcncRZQ7X6eojrDtAsHGVEzmDEN oG7jgOB4uJSSUu7UjkWrFO+3mlx44WBs701vGtWdF7F43TX9+MsAMg8d4J4Of7wKHnm3 7zbgML1SvnGevlJ05eAlOK4xOMakEHGu++o+H1rvKs3n0DmRBkJlf6ZXClbLtsf+qQX9 EN78s6cfiUaJ644Rqs1uz4EXFVAubdx8GVUnTkgDZxmjHmUQEnllCCOew+iGVxRJiXUu dhOg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:dkim-signature; bh=woEG6I0sfEGGLeu6jOQkQD9fV+v4+KVZGarzOOeRXwE=; b=syRL+1haF5q4LXykEMnwX/XTxow16GDlh3OuZBn4ELF2+0841XnfEYylWPk/nGqoEB BLI8mh2dJaaomd6Dce86I4jGWdy4dssR3w0W0QIX1EVaoLNFAoxkcFngei0pz/Z+qXSU zWQEMfvYk1qwhtd4jg3+OiemXgicQUnxFPiC5oVGSGdh1uhvDfRh7vEMbC87ztWYYlTi M16IGYuITQLSqTpJYR9JBrfs+4HShJ5HUBXUPtCWRBQ3uRt40gWqaxB7AdXm5UPE7enu tqgDY0hHj0AMtwltg6wva/mDyMvaiptBFsCplwW6th3MDiWHSBn7PhmM7dbTE+3tevU/ QDnA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@alien8.de header.s=dkim header.b=B6FCFTmr; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alien8.de Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id m130si1366660pga.119.2021.04.21.18.18.28; Wed, 21 Apr 2021 18:18:40 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@alien8.de header.s=dkim header.b=B6FCFTmr; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alien8.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245306AbhDUSvI (ORCPT + 99 others); Wed, 21 Apr 2021 14:51:08 -0400 Received: from mail.skyhub.de ([5.9.137.197]:48366 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243061AbhDUSvI (ORCPT ); Wed, 21 Apr 2021 14:51:08 -0400 Received: from zn.tnic (p2e58483a.dip0.t-ipconnect.de [46.88.72.58]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 1EC381EC01B7; Wed, 21 Apr 2021 20:50:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1619031034; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=woEG6I0sfEGGLeu6jOQkQD9fV+v4+KVZGarzOOeRXwE=; b=B6FCFTmrbZfFBSyHDjWVsyU7iuc4b6PJEwAogaQydwLo5UA9TuEBpaTjJvfWy/fRC0tIE1 vqSO9CvCqEaHN8q1qBVCXQG1f1lH2POkrNCZqwP3X8WFBR8jlfMqmAubmN/159p/L11D6F 2bKLPGLb6bjRDG983501aGhSfEJcOGo= Date: Wed, 21 Apr 2021 20:48:26 +0200 From: Borislav Petkov To: Bandan Das Cc: Randy Dunlap , Ramakrishna Saripalli , linux-kernel@vger.kernel.org, x86@kernel.org, tglx@linutronix.de, mingo@redhat.com, Jonathan Corbet Subject: Re: [PATCH 4/4] x86/speculation: Add PSF mitigation kernel parameters Message-ID: <20210421184826.GA3120@zn.tnic> References: <20210421090117.22315-1-rsaripal@amd.com> <20210421090117.22315-5-rsaripal@amd.com> <4c688fc7-67df-3187-54b2-bf20e510fb39@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 21, 2021 at 02:32:13PM -0400, Bandan Das wrote: > Maybe, rename the parameter to something like psfd_disable, then off > -> disables mitigation and on -> enables it. Or just rewriting this to > off -> turns off predictive store forwarding is probably ok too. Yes: off - Turns off predictive store forwarding. on - Turns on... Ramakrishna, you don't have to call this a mitigation - this is a flag which controls the feature. Also, those 4 patches can be merged into a single one which simply adds the feature along with the boot-time controls. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette