Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751544AbeAEEHt (ORCPT + 1 other); Thu, 4 Jan 2018 23:07:49 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:55360 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751364AbeAEEHs (ORCPT ); Thu, 4 Jan 2018 23:07:48 -0500 Subject: Re: 4.15-rc6+ hang To: Linus Torvalds Cc: Linux Kernel Mailing List , Dhaval Giani , Greg Kroah-Hartman , Peter Zijlstra , Ingo Molnar , Thomas Gleixner References: From: Tom Hromatka Message-ID: <1e1b4534-b0b4-90c9-479b-29058047f1e9@oracle.com> Date: Thu, 4 Jan 2018 21:02:17 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8764 signatures=668651 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1801050052 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On 01/04/2018 07:22 PM, Linus Torvalds wrote: > On Thu, Jan 4, 2018 at 5:36 PM, Tom Hromatka wrote: >> I am seeing a hang running kernel 4.15-rc6+ on a vanilla VirtualBox VM. >> (VirtualBox version 5.0.40) > Any chance of bisecting this? > > I could imagine that all the stuff we now do for page table isolation > might confuse the VM. Yes, I can try and bisect this. >> When I boot this kernel, it hangs and falls back into dracut. Here's >> the boot log immediately prior to the hang: > So a few questions: > > (a) does it work with "pti=no" on the kernel command line pti=no also hung in the same fashion with the 4.15-rc6+ kernel. > > (b) what was the last kernel that worked? Is 4.15-rc5 fine, for example? 4.15-rc5 hung as well.  I'll go further back and see what I can find. >> [ 0.000000] ------------[ cut here ]------------ >> [ 0.000000] XSAVE consistency problem, dumping leaves > I think this is a vbox issue, with virtualbox not exposing all the > xsave state, so that when the kernel adds up the xsave areas, the end > result doesn't match what the total size is reported to be. It seems probable that this is a VirtualBox issue.  I was able to boot my exact 4.15-rc6+ kernel in qemu-kvm v1.5.3 just fine. > > I suspect you _should_ have gotten that before too, independently of the hang. 4.15-rc5 also exhibits the xsave issue in VirtualBox. Thanks. Tom > > Linus