From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754156AbeDYLGn (ORCPT ); Wed, 25 Apr 2018 07:06:43 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:46944 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752831AbeDYLGh (ORCPT ); Wed, 25 Apr 2018 07:06:37 -0400 Subject: Re: [PATCH 01/10] vfio: ccw: Moving state change out of IRQ context To: Cornelia Huck Cc: Pierre Morel , Dong Jia Shi , pasic@linux.vnet.ibm.com, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org References: <1524149293-12658-1-git-send-email-pmorel@linux.vnet.ibm.com> <1524149293-12658-2-git-send-email-pmorel@linux.vnet.ibm.com> <20180424065442.GV12194@bjsdjshi@linux.vnet.ibm.com> <20180424115929.5b5e1ff0.cohuck@redhat.com> <245ee547-75bc-95f5-5acb-bfa96f91afd2@linux.ibm.com> <20180425085726.3a8a97a5.cohuck@redhat.com> From: Halil Pasic Date: Wed, 25 Apr 2018 13:06:31 +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: <20180425085726.3a8a97a5.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 18042511-0020-0000-0000-000004159FBF X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18042511-0021-0000-0000-000042AA0B2D Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-04-25_03:,, 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=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1804250105 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/25/2018 08:57 AM, Cornelia Huck wrote: >> AFAIU this will be the problem of the person implementing the clear >> and the halt for vfio-ccw. I.e. it's a non-problem right now. > Well, that person is me:) I will post some RFC Real Soon Now if I stop > getting sidetracked... > Makes sense. It should be fine either way AFAIU. CSCH, more precisely the clear function is supposed to clear the interruption request(s) too. But I guess there is no way of the CP to identify an I/O interrupt that should have been cleared -- that is catch us disrespecting the architecture. I can't think of a way to establish must happen before relationship... But discarding the first interrupt and delivering just one for the CSCH is fine too for the same reason. Regards, Halil