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 631A4C7EE2F for ; Thu, 25 May 2023 13:56:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241423AbjEYN4S (ORCPT ); Thu, 25 May 2023 09:56:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37606 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241378AbjEYN4O (ORCPT ); Thu, 25 May 2023 09:56:14 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF6AD186; Thu, 25 May 2023 06:56:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1685022972; x=1716558972; h=message-id:date:mime-version:subject:to:references:from: in-reply-to:content-transfer-encoding; bh=gUhiFPchgWyeHeR6vpngEYZDAoF6lLu30ZSMdDh296U=; b=n7fW2eBhgenDdGRE85iz41FCRbWQWWU8w43UddOMPEAQ6mzmPUlG5wMi 9ce1YHwdbcajzTXtc7012ZUfcBab9oUYbNspAUMqwi7YV+IiVKMdwzQ8v HhwE8dRHDuaMNPfnajm4CiHMJtczF7pPlOLcULkA2A+kRCn7unV73Mfle oYgJMfL1sTl9AZ9ubEXrmtYQPZJ4Ua8d5qAZEstXCzAcwiKBdFGkRAtn5 tJJW1vsnQ+tVfiRTKqUI39UoHhwHia7nrex8XUva/dA8z6mCDCV96p04G 1fl/KG/UBl4thGx9llLCjjlMkGNHDbM2WzTs8nDbiHaal0KvQ+9gqKpOu Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10721"; a="440245113" X-IronPort-AV: E=Sophos;i="6.00,191,1681196400"; d="scan'208";a="440245113" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 May 2023 06:56:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10721"; a="794687234" X-IronPort-AV: E=Sophos;i="6.00,191,1681196400"; d="scan'208";a="794687234" Received: from shuklaas-mobl1.amr.corp.intel.com (HELO [10.212.186.148]) ([10.212.186.148]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 May 2023 06:56:11 -0700 Message-ID: <13922610-b9bc-ab4b-8482-9aae238396c7@intel.com> Date: Thu, 25 May 2023 06:56:10 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [EXTERNAL] Re: [PATCH 1/2] x86/Kconfig: Allow CONFIG_X86_MPPARSE disable for OF platforms Content-Language: en-US To: Saurabh Singh Sengar , Saurabh Sengar , "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "x86@kernel.org" , "hpa@zytor.com" , KY Srinivasan , Haiyang Zhang , "wei.liu@kernel.org" , Dexuan Cui , "Michael Kelley (LINUX)" , "linux-kernel@vger.kernel.org" , "linux-hyperv@vger.kernel.org" References: <1683816877-10747-1-git-send-email-ssengar@linux.microsoft.com> <9b88ddaf-c5c5-0244-5be7-12400ee54e11@intel.com> <33d7800b-7870-6755-b057-f734fa7accd6@intel.com> From: Dave Hansen In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/25/23 00:06, Saurabh Singh Sengar wrote: > When CONFIG_X86_MPPARSE is enabled, the kernel will scan low memory, > looking for MP tables. In Hyper-V VBS setup, lower memory is assigned to VTL0. > This lower memory may contain the actual MPPARSE table for VTL0, > which can confuse the VTLx kernel and cause issues. (x > 0) This still just seems wrong. If an action crashes the kernel because of changes, we don't just compile it out and move on. We add enumeration for the new feature that's causing it and turn off the action at runtime.