From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751730AbeCZLZm (ORCPT ); Mon, 26 Mar 2018 07:25:42 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:44818 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751107AbeCZLZj (ORCPT ); Mon, 26 Mar 2018 07:25:39 -0400 Subject: Re: [PATCH 0/4] vfio: ccw: error handling fixes and improvements To: Cornelia Huck , Dong Jia Shi Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, borntraeger@de.ibm.com, pmorel@linux.vnet.ibm.com References: <20180321020822.86255-1-bjsdjshi@linux.vnet.ibm.com> <20180326110224.1af0ad13.cohuck@redhat.com> From: Halil Pasic Date: Mon, 26 Mar 2018 13:25:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180326110224.1af0ad13.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 18032611-0044-0000-0000-0000053FE458 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18032611-0045-0000-0000-0000287EFAC5 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-03-26_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1803260125 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/26/2018 11:02 AM, Cornelia Huck wrote: > On Wed, 21 Mar 2018 03:08:18 +0100 > Dong Jia Shi wrote: > >> Hi Conny, >> >> Halil reported a host crash when using vfio-ccw. The root cause of the problem >> is that vfio_pin_pages fails with EINVAL for reasons unknown. He has >> experienced such failures after online-ing a dasd in the guest (the dasd has 3 >> partitions, hat may or may not have any significance). The problem isn't >> experienced on every attempt to online the dasd, and breaking at css_do_ssch >> seems to make things work. >> >> One thing is sure: the host kernel should not crash under the described >> circumstances. >> >> To fix the problem, the first patch of this series fixes the cleanup when >> cp_prefetch fails in the higher level. The 2nd and the 3rd patches provide >> correctness and denfensive actions for the interfaces in the lower level. > > So, is the first patch stable material? I think it should be. > >> >> The 4th patch is trying to add tracepoints for vfio-ccw, so that we can debug >> such issue easier in future. > > Tracepoints are nice :) > >> >> For details see the commit message portions of the inividual patches. > > Still digging through the post-vacation mail pile, will do more looking > later. > > >> Thanks. >> >> Dong Jia Shi (2): >> vfio: ccw: refactor and improve pfn_array_alloc_pin() >> vfio: ccw: set ccw->cda to NULL defensively >> >> Halil Pasic (2): >> vfio: ccw: fix cleanup if cp_prefetch fails >> vfio: ccw: add traceponits for interesting error paths >> >> drivers/s390/cio/Makefile | 1 + >> drivers/s390/cio/vfio_ccw_cp.c | 121 ++++++++++++++++++++------------------ >> drivers/s390/cio/vfio_ccw_fsm.c | 13 ++++ >> drivers/s390/cio/vfio_ccw_trace.h | 86 +++++++++++++++++++++++++++ >> 4 files changed, 163 insertions(+), 58 deletions(-) >> create mode 100644 drivers/s390/cio/vfio_ccw_trace.h >> >