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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 AEC64C43142 for ; Wed, 27 Jun 2018 08:39:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6018D265F2 for ; Wed, 27 Jun 2018 08:39:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6018D265F2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933402AbeF0Ijm (ORCPT ); Wed, 27 Jun 2018 04:39:42 -0400 Received: from foss.arm.com ([217.140.101.70]:56550 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932234AbeF0Ijk (ORCPT ); Wed, 27 Jun 2018 04:39:40 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 10C4B18A; Wed, 27 Jun 2018 01:39:40 -0700 (PDT) Received: from [10.1.206.34] (melchizedek.cambridge.arm.com [10.1.206.34]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B432B3F5AD; Wed, 27 Jun 2018 01:39:37 -0700 (PDT) Subject: Re: KVM guest sometimes failed to boot because of kernel stack overflow if KPTI is enabled on a hisilicon ARM64 platform. To: Wei Xu Cc: Will Deacon , mark.rutland@arm.com, catalin.marinas@arm.com, Linuxarm , Zhangyi ac , suzuki.poulose@arm.com, marc.zyngier@arm.com, "Xiongfanggou (James)" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, dave.martin@arm.com, "Liyuan (Larry, Turing Solution)" , libeijian@hisilicon.com References: <5B2A6218.3030201@hisilicon.com> <20180620144257.GB27776@arm.com> <5B2A7832.4010502@hisilicon.com> <5B2A7FE1.5040607@hisilicon.com> <5B2B6DEA.2090100@hisilicon.com> <5B3274FC.7000206@hisilicon.com> <20180626174746.GO23375@arm.com> From: James Morse Message-ID: <942e76b6-a46a-6c5e-5ec3-67daca636d43@arm.com> Date: Wed, 27 Jun 2018 09:39:36 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180626174746.GO23375@arm.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 Hi Wei, On 26/06/18 18:47, Will Deacon wrote: > On Wed, Jun 27, 2018 at 01:16:44AM +0800, Wei Xu wrote: >> [ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x480fd010] >> [ 0.000000] Linux version 4.18.0-rc2-58583-g7daf201-dirty > > I'm still suspicious that this is 4.18-rc2 with "no change on top" ^^^ ! Some examples: For comparison, when I boot v4.17 it looks like this: | Linux version 4.17.0 (morse@melchizedek) (gcc version 4.9.3 20141031 | (prerelease) (Linaro GCC 2014.11)) #9886 SMP PREEMPT Thu Jun 21 10:30:55 BST | 2018 If I apply some extra patches and make some uncommitted changes, it looks like this: | Linux version 4.17.0-00025-ga22ca2234824-dirty (morse@melchizedek) (gcc | version 4.9.3 20141031 (prerelease) (Linaro GCC 2014.11)) #9887 SMP PREEMPT | Thu Jun 21 10:46:22 BST 2018 Hence we read your '4.17.0-45864-g29dcea8-dirty' line as v4.17 with extra patches and uncommited changes, and similar with this v4.18-rc2. I agree 7daf201 is the head commit for v4.18-rc2, but something has gone wrong here. Could you try building from a fresh clone of Linus' tree? (I suspect at some point you've applied a patch, and have then been merging upstream, instead of 'fast forwarding') Thanks, James