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=-5.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_2 autolearn=no 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 57A9DC00A89 for ; Fri, 30 Oct 2020 17:54:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C0A2D20724 for ; Fri, 30 Oct 2020 17:54:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="NYrLVd/a" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726860AbgJ3RyT (ORCPT ); Fri, 30 Oct 2020 13:54:19 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:61024 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726061AbgJ3RyT (ORCPT ); Fri, 30 Oct 2020 13:54:19 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 09UHVbO4115974; Fri, 30 Oct 2020 13:54:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=date : from : to : cc : subject : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=pp1; bh=hQ9GXhTjWObrlTROl5RhWZO9DgdbO9lvN76ob0g41pw=; b=NYrLVd/atGE6GExxexNNiWKrExV4LXm/xSAU5ApiDrivKJAxypU+2qmhZegqbnixQNc5 Sdr8IjmWpWMjfWLupXXGpOo1hdZYkebjXv0yeRKD/zdNmkVQBB8fnswrDerYRlxzZ1kH J/t4b8Xe5aAgfVPYZ8PRXXJxXamSzEZKVtxCNdeTAwVKKJEYE/czCgOlVjSzQU9pw/Ne bErX55hJHSTorqaKQ/yl6dNyV5ZvhPSAXITdJYx7T/uAtDc631RXYMhBl4e6p6JBj+f+ 4mHnMT8voeoZ+M4q67DekaDT1fAGInt4k0a/OZPVxRW4RZBQ39DM8iHI3pzZTApf+JKj 7w== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 34gq9arp2b-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 30 Oct 2020 13:54:14 -0400 Received: from m0098416.ppops.net (m0098416.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 09UHVh8j116383; Fri, 30 Oct 2020 13:54:13 -0400 Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0b-001b2d01.pphosted.com with ESMTP id 34gq9arp1k-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 30 Oct 2020 13:54:13 -0400 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 09UHqLYQ015819; Fri, 30 Oct 2020 17:54:11 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma04ams.nl.ibm.com with ESMTP id 34f8craa5v-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 30 Oct 2020 17:54:11 +0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 09UHs8rV17760698 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 30 Oct 2020 17:54:08 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A04CBA405B; Fri, 30 Oct 2020 17:54:08 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EA14EA4051; Fri, 30 Oct 2020 17:54:07 +0000 (GMT) Received: from oc2783563651 (unknown [9.145.172.93]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 30 Oct 2020 17:54:07 +0000 (GMT) Date: Fri, 30 Oct 2020 18:54:06 +0100 From: Halil Pasic To: Tony Krowiak Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@linux.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com, mjrosato@linux.ibm.com, alex.williamson@redhat.com, kwankhede@nvidia.com, fiuczy@linux.ibm.com, frankja@linux.ibm.com, david@redhat.com, hca@linux.ibm.com, gor@linux.ibm.com Subject: Re: [PATCH v11 01/14] s390/vfio-ap: No need to disable IRQ after queue reset Message-ID: <20201030185406.7fa13fbe.pasic@linux.ibm.com> In-Reply-To: <7a2c5930-9c37-8763-7e5d-c08a3638e6a1@linux.ibm.com> References: <20201022171209.19494-1-akrowiak@linux.ibm.com> <20201022171209.19494-2-akrowiak@linux.ibm.com> <20201027074846.30ee0ddc.pasic@linux.ibm.com> <7a2c5930-9c37-8763-7e5d-c08a3638e6a1@linux.ibm.com> Organization: IBM X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312,18.0.737 definitions=2020-10-30_07:2020-10-30,2020-10-30 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 mlxscore=0 priorityscore=1501 suspectscore=2 adultscore=0 mlxlogscore=924 spamscore=0 bulkscore=0 malwarescore=0 impostorscore=0 phishscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010300127 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 29 Oct 2020 19:29:35 -0400 Tony Krowiak wrote: > >> @@ -1177,7 +1166,10 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev) > >> */ > >> if (ret) > >> rc = ret; > >> - vfio_ap_irq_disable_apqn(AP_MKQID(apid, apqi)); > >> + q = vfio_ap_get_queue(matrix_mdev, > >> + AP_MKQID(apid, apqi)); > >> + if (q) > >> + vfio_ap_free_aqic_resources(q); [..] > > > > Under what circumstances do we expect !q? If we don't, then we need to > > complain one way or another. > > In the current code (i.e., prior to introducing the subsequent hot > plug patches), an APQN can not be assigned to an mdev unless it > references a queue device bound to the vfio_ap device driver; however, > there is nothing preventing a queue device from getting unbound > while the guest is running (one of the problems mostly resolved by this > series). In that case, q would be NULL. But if the queue does not belong to us any more it does not make sense call vfio_ap_mdev_reset_queue() on it's APQN, or? I think we should have if(!q) continue; at the very beginning of the loop body, or we want to be sure that q is not null.