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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 EAD73C4743E for ; Sun, 6 Jun 2021 19:39:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C678661377 for ; Sun, 6 Jun 2021 19:39:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229894AbhFFTll (ORCPT ); Sun, 6 Jun 2021 15:41:41 -0400 Received: from mail-lf1-f44.google.com ([209.85.167.44]:41515 "EHLO mail-lf1-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229573AbhFFTlk (ORCPT ); Sun, 6 Jun 2021 15:41:40 -0400 Received: by mail-lf1-f44.google.com with SMTP id v8so22440738lft.8 for ; Sun, 06 Jun 2021 12:39:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=P7An2hiLHGrbouqS/7tRGUe6/Rk56Kt/+cv6MVnKXHw=; b=X8PSQcCXi9TFSGp9uWLEWYLwqtECkft4cK25eAUrYbl7/k0fofUzW1c21vgoGXqIYU dQ4Hem4Zryf7koLchCfD4ceiGeDTdMHvqYMp7G+rStj8EzD6cbYYICA6UCD7/lAvpKR5 BqGJs7qDa9ChMulRvIlfwScs6RUibNr5ta6ow= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=P7An2hiLHGrbouqS/7tRGUe6/Rk56Kt/+cv6MVnKXHw=; b=It5U2LuHGhZU4PIyAa/BUiXWgCAsJ/cefNvIvTPCDxT1YiwMtTxyb2qMoufpFPHHDz SuY+3oNdfbJq33vYVLILl14z9QkaedSh3pMx8aQYq2NyP6vBdBVaWb+XyX7dSqaQC0GN cIGxprVTYoiBu5ZcvyV/OWegZ+XYnGtCENElBiLaia7YgNnBn03w3SXXggEuLFNAXEw+ OSE8CFGh5hECX70SgtIyKKk4BZqj7b/iu0k6gZz8HZdcBKqKzX9LrUyMu15nVvhZT5fg iEUyeb7TXa73tqwDBZmwOjL2yDOCnAsRVHPXqYhxUOewhIA4grU+gRBRLSE8dRk7j6pi 7sow== X-Gm-Message-State: AOAM531cqqBmioTNZ8qnAdxg6Woa7vFX//OGiraenC43q9lvPe0abqvN PIjnd0qYf0z6FM/nYda9r/M3eo/q/D4AlLp0iH4= X-Google-Smtp-Source: ABdhPJwaI6TqdZVZm1ndd6thxcsbLTeZ5d/WjPtEsx3+LjmglOkgeOjVLKsoDeCkugrxVXUla+jP0Q== X-Received: by 2002:ac2:5d69:: with SMTP id h9mr9137998lft.603.1623008329159; Sun, 06 Jun 2021 12:38:49 -0700 (PDT) Received: from mail-lj1-f179.google.com (mail-lj1-f179.google.com. [209.85.208.179]) by smtp.gmail.com with ESMTPSA id q126sm1563705ljq.111.2021.06.06.12.38.48 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 06 Jun 2021 12:38:48 -0700 (PDT) Received: by mail-lj1-f179.google.com with SMTP id a4so19043024ljd.5 for ; Sun, 06 Jun 2021 12:38:48 -0700 (PDT) X-Received: by 2002:a2e:b04c:: with SMTP id d12mr11975196ljl.465.1623008328440; Sun, 06 Jun 2021 12:38:48 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Linus Torvalds Date: Sun, 6 Jun 2021 12:38:32 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [GIT PULL] x86/urgent for v5.13-rc5 To: Borislav Petkov , Mike Rapoport Cc: x86-ml , lkml Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jun 6, 2021 at 12:55 AM Borislav Petkov wrote: > > - Do away with all the wankery of reserving X amount of memory in > the first megabyte to prevent BIOS corrupting it and simply and > unconditionally reserve the whole first megabyte. This seems a bit draconic. How does this work at all under Windows? There must be some windows knowledge about what the BIOS updates that we're not aware of. I've pulled it, but it does seem like something odd is going on. And that Fixes: a799c2bd29d1 ("x86/setup: Consolidate early memory reservations") makes me go "Umm.." too. What did a799c2bd29d1 actually break? It looks like it was meant to be a no-op consolidation - if somebody bisected to it, I think that is a sign that there's something odd there. Linus