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 18976C001DF for ; Wed, 2 Aug 2023 23:10:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230043AbjHBXK1 (ORCPT ); Wed, 2 Aug 2023 19:10:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229480AbjHBXK0 (ORCPT ); Wed, 2 Aug 2023 19:10:26 -0400 Received: from mail-pf1-f178.google.com (mail-pf1-f178.google.com [209.85.210.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27EBE1727; Wed, 2 Aug 2023 16:10:26 -0700 (PDT) Received: by mail-pf1-f178.google.com with SMTP id d2e1a72fcca58-686ba97e4feso320711b3a.0; Wed, 02 Aug 2023 16:10:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691017825; x=1691622625; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=R5J1Jr2A+AmEVJ3YQaMd97ioATpANcvZMYjjl7OLHuI=; b=igDt8av7q9/TvtrAqeDAp0L2mCus9QHlRFsbYHHU+sP4RaBQhtcxhuQ5kRTK1xVATP nDYzcw7l3RPd6sKyd3Xg/TIZRi5JXP3dkDC7Y0USbeY7I5OLBtIXJ4ohQJW+yoo8ypaq yxsNIQxx5qw3Hm121FScz9BcVZP4gOgEtA1FRceKQvT0ZmnpVG/tkt5OgX1FOb4k0hSd ZmQfuXU7nHG5CQpA1W5ahWoEmXMIGI1Cni/GQMegQKBOcKtyq5Kz5YQ/qWwrICmkaGQY fbfNiLT+iHwcjQh8mM4st/jL8A5W6WUWFEEmM0WGUdZTEoclXgWg4EaTWDityR2jKxe3 0+uA== X-Gm-Message-State: ABy/qLbSihRQCaNo8nLsS1WUQ+7DUd2u3AVK3xNP2wTc1u4TDsUvHg8v CgrglWKwkOfZUx5jdmi7UFM= X-Google-Smtp-Source: APBJJlHFROEuKw8A9slDlgdQWEWfiiTvqmon2ZRST9cuflAhaS1fTIhO0K67Q6oBF+lcAyyTKX4KIQ== X-Received: by 2002:a05:6a20:548c:b0:138:1980:1837 with SMTP id i12-20020a056a20548c00b0013819801837mr22535642pzk.13.1691017825606; Wed, 02 Aug 2023 16:10:25 -0700 (PDT) Received: from liuwe-devbox-debian-v2 ([20.69.120.36]) by smtp.gmail.com with ESMTPSA id u19-20020aa78493000000b00666e649ca46sm11519994pfn.101.2023.08.02.16.10.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Aug 2023 16:10:25 -0700 (PDT) Date: Wed, 2 Aug 2023 23:10:19 +0000 From: Wei Liu To: Saurabh Sengar Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, mikelley@microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, hpa@zytor.com Subject: Re: [PATCH v3] x86/hyperv: add noop functions to x86_init mpparse functions Message-ID: References: <1687537688-5397-1-git-send-email-ssengar@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1687537688-5397-1-git-send-email-ssengar@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Fri, Jun 23, 2023 at 09:28:08AM -0700, Saurabh Sengar wrote: > Hyper-V can run VMs at different privilege "levels" known as Virtual > Trust Levels (VTL). Sometimes, it chooses to run two different VMs > at different levels but they share some of their address space. In > such setups VTL2 (higher level VM) has visibility of all of the > VTL0 (level 0) memory space. > > When the CONFIG_X86_MPPARSE is enabled for VTL2, the VTL2 kernel > performs a search within the low memory to locate MP tables. However, > in systems where VTL0 manages the low memory and may contain valid > tables, this scanning can result in incorrect MP table information > being provided to the VTL2 kernel, mistakenly considering VTL0's MP > table as its own > > Add noop functions to avoid MP parse scan by VTL2. > > Signed-off-by: Saurabh Sengar Applied to hyperv-fixes. Thanks.