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=-1.0 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 DFA77C43381 for ; Thu, 28 Mar 2019 13:06:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A945E2173C for ; Thu, 28 Mar 2019 13:06:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726363AbfC1NGz (ORCPT ); Thu, 28 Mar 2019 09:06:55 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:37658 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725948AbfC1NGz (ORCPT ); Thu, 28 Mar 2019 09:06:55 -0400 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x2SCwqK8085341 for ; Thu, 28 Mar 2019 09:06:54 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2rgx0qtmx8-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 28 Mar 2019 09:06:53 -0400 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 28 Mar 2019 13:06:49 -0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x2SD6l8N14155890 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 28 Mar 2019 13:06:47 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8F8A4A405B; Thu, 28 Mar 2019 13:06:47 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EE0B6A4054; Thu, 28 Mar 2019 13:06:46 +0000 (GMT) Received: from [9.152.224.145] (unknown [9.152.224.145]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 28 Mar 2019 13:06:46 +0000 (GMT) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v6 2/7] s390: ap: new vfio_ap_queue structure To: Tony Krowiak , borntraeger@de.ibm.com Cc: alex.williamson@redhat.com, cohuck@redhat.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, frankja@linux.ibm.com, pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com References: <1553265828-27823-1-git-send-email-pmorel@linux.ibm.com> <1553265828-27823-3-git-send-email-pmorel@linux.ibm.com> <169eec34-6397-3150-27df-9985c9e711b8@linux.ibm.com> From: Pierre Morel Date: Thu, 28 Mar 2019 14:06:46 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <169eec34-6397-3150-27df-9985c9e711b8@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19032813-4275-0000-0000-000003209149 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19032813-4276-0000-0000-0000382F2F04 Message-Id: <1b64ad7b-2a7c-b604-1adb-af400e7be516@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-03-28_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1903280091 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 26/03/2019 21:45, Tony Krowiak wrote: > On 3/22/19 10:43 AM, Pierre Morel wrote: >> The AP interruptions are assigned on a queue basis and >> the GISA structure is handled on a VM basis, so that >> we need to add a structure we can retrieve from both side > > s/side/sides/ OK > >> holding the information we need to handle PQAP/AQIC interception >> and setup the GISA. > > s/setup/set up/ OK ...snip... >> + >> +static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q) >> +{ >> +    struct ap_queue_status status; >> +    int retry = 1; >> + >> +    do { >> +        status = ap_zapq(q->apqn); >> +        switch (status.response_code) { >> +        case AP_RESPONSE_NORMAL: >> +            return 0; >> +        case AP_RESPONSE_RESET_IN_PROGRESS: >> +        case AP_RESPONSE_BUSY: >> +            msleep(20); >> +            break; >> +        default: >> +            /* things are really broken, give up */ > > I'm not sure things are necessarily broken. We could end up here if > the AP is removed from the configuration via the SE or SCLP Deconfigure > Adjunct Processor command. OK, but note that it is your original comment I just moved the function here ;) > >> +            return -EIO; >> +        } >> +    } while (retry--); >> + >> +    return -EBUSY; >> +} >> + >>   static void vfio_ap_matrix_init(struct ap_config_info *info, >>                   struct ap_matrix *matrix) >>   { >> @@ -45,6 +107,7 @@ static int vfio_ap_mdev_create(struct kobject >> *kobj, struct mdev_device *mdev) >>           return -ENOMEM; >>       } >> +    INIT_LIST_HEAD(&matrix_mdev->qlist); >>       vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix); >>       mdev_set_drvdata(mdev, matrix_mdev); >>       mutex_lock(&matrix_dev->lock); >> @@ -113,162 +176,189 @@ static struct attribute_group >> *vfio_ap_mdev_type_groups[] = { >>       NULL, >>   }; >> -struct vfio_ap_queue_reserved { >> -    unsigned long *apid; >> -    unsigned long *apqi; >> -    bool reserved; >> -}; >> +static void vfio_ap_free_queue(int apqn, struct ap_matrix_mdev >> *matrix_mdev) >> +{ >> +    struct vfio_ap_queue *q; >> + >> +    q = vfio_ap_get_queue(apqn, &matrix_mdev->qlist); >> +    if (!q) >> +        return; >> +    q->matrix_mdev = NULL; >> +    vfio_ap_mdev_reset_queue(q); > > I'm wondering if it's necessary to reset the queue here. The only time > a queue is used is when a guest using the mdev device is started. When > that guest is terminated, the fd for the mdev device is closed and the > mdev device's release callback is invoked. The release callback resets > the queues assigned to the mdev device. Is it really necessary to > reset the queue again when it is unassigned even if there would have > been no subsequent activity? Yes, it is necessary, the queue can be re-assigned to another guest later. Release will only be called when unbinding the queue from the driver. > >> +    list_move(&q->list, &matrix_dev->free_list); >> +} ...snip... >> +    for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, AP_DEVICES) { >> +        apqn = AP_MKQID(apid, apqi); >> +        q = vfio_ap_find_queue(apqn); >> +        if (!q) { >> +            ret = -EADDRNOTAVAIL; >> +            goto rewind; >> +        } >> +        if (q->matrix_mdev) { > > If somebody assigns the same domain a second time, the assignment will > fail because the matrix_mdev will already have been associated with the > queue. I don't think it is appropriate to fail the assignment if the It is usual to report a failure in the case the operation requested has already be done. But we can do as you want. Any other opinion? > q->matrix_mdev is the same as the input matrix_mdev. This should be > changed to: > >     if (q->matrix_mdev != matrix_mdev) You surely want to say: add this, not change to this. ;) > Thanks for commenting, Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany