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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 EF3A6C3A5A6 for ; Mon, 23 Sep 2019 10:22:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CEF66206C2 for ; Mon, 23 Sep 2019 10:22:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439511AbfIWKW1 (ORCPT ); Mon, 23 Sep 2019 06:22:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50558 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406701AbfIWKW0 (ORCPT ); Mon, 23 Sep 2019 06:22:26 -0400 Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D84F1811DC for ; Mon, 23 Sep 2019 10:22:25 +0000 (UTC) Received: by mail-wm1-f69.google.com with SMTP id 190so6441005wme.4 for ; Mon, 23 Sep 2019 03:22:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=fOXb2zotSIWB4X/sQrsrANj/mMFRoi6WdNsUfB4y3ds=; b=Cecj5dX3pmzInOw4I5MwxmIrlb1KoTXCIhxWDzK9Oxx+xFBOvk2tvPFs8jztsEeYsF GpPrxPisoM5alD9LuuuxPcAb2Ry+P+c6mXmt4/2RUllWLN0MAPGLqax7hJJZOtsExtyZ DhdQJn/fgC2fHPzrgeK+qSZvCPkRh8QM+vNIuVZi/cuSrVN+U2aUDt3O4QbnTMvG6wlU K2xqy3G50KH1cZfXDn2Q2Fu1HMqgWAUb63nLqqR+2UFKnTaFXunk+CMVv+HSq417goSW ZDV7bDNlVqGhL1mzSsz6O/kuXVoqTFSsFop9bH6KAY/F56HphDjjSnetw7svVACN7lz8 8iow== X-Gm-Message-State: APjAAAXsBOmuYhF0+730zaVyQIXRzKlbu/CQK+sJyaNGbZQsxHiczMBj yXqd76WA1rNqa8vkwJuEnB/VFqnvqT/g0KjDRVHPzGgl59oNSYdP/eY3JFQjVS9JZ/YETE4Swcu wAPKRthxkVAX8DuwU2FIfHGEA X-Received: by 2002:adf:f44e:: with SMTP id f14mr19897297wrp.290.1569234144366; Mon, 23 Sep 2019 03:22:24 -0700 (PDT) X-Google-Smtp-Source: APXvYqz6zfWDCrO5uyrF7XiNRNtg5AchHWZTbVkzNHhwvuNee2mlm3NGz1GASMsttwusekXqn0QzPw== X-Received: by 2002:adf:f44e:: with SMTP id f14mr19897284wrp.290.1569234144093; Mon, 23 Sep 2019 03:22:24 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:9520:22e6:6416:5c36? ([2001:b07:6468:f312:9520:22e6:6416:5c36]) by smtp.gmail.com with ESMTPSA id o12sm17311097wrm.23.2019.09.23.03.22.23 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 23 Sep 2019 03:22:23 -0700 (PDT) Subject: Re: [PATCH 01/17] x86: spec_ctrl: fix SPEC_CTRL initialization after kexec To: Andrea Arcangeli Cc: Vitaly Kuznetsov , "Dr. David Alan Gilbert" , Marcelo Tosatti , Peter Xu , kvm@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190920212509.2578-1-aarcange@redhat.com> <20190920212509.2578-2-aarcange@redhat.com> From: Paolo Bonzini Openpgp: preference=signencrypt Message-ID: Date: Mon, 23 Sep 2019 12:22:23 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190920212509.2578-2-aarcange@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20/09/19 23:24, Andrea Arcangeli wrote: > We can't assume the SPEC_CTRL msr is zero at boot because it could be > left enabled by a previous kernel booted with > spec_store_bypass_disable=on. > > Without this fix a boot with spec_store_bypass_disable=on followed by > a kexec boot with spec_store_bypass_disable=off would erroneously and > unexpectedly leave bit 2 set in SPEC_CTRL. > > Signed-off-by: Andrea Arcangeli Can you send this out separately, so that Thomas et al. can pick it up as a bug fix? Thanks, Paolo