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 53CAAC4321D for ; Wed, 15 Aug 2018 16:59:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A55F2152C for ; Wed, 15 Aug 2018 16:59:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4A55F2152C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729950AbeHOTwp (ORCPT ); Wed, 15 Aug 2018 15:52:45 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:36430 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729388AbeHOTwp (ORCPT ); Wed, 15 Aug 2018 15:52:45 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7FGxXOi057337 for ; Wed, 15 Aug 2018 12:59:47 -0400 Received: from e35.co.us.ibm.com (e35.co.us.ibm.com [32.97.110.153]) by mx0a-001b2d01.pphosted.com with ESMTP id 2kvn0s0qxj-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 15 Aug 2018 12:59:47 -0400 Received: from localhost by e35.co.us.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) Wed, 15 Aug 2018 10:59:42 -0600 Received: from b03ledav002.gho.boulder.ibm.com (b03ledav002.gho.boulder.ibm.com [9.17.130.233]) by b03cxnp08027.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w7FGxdNJ13042018 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 15 Aug 2018 09:59:39 -0700 Received: from b03ledav002.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1A31F136059; Wed, 15 Aug 2018 10:59:39 -0600 (MDT) Received: from b03ledav002.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D197D136051; Wed, 15 Aug 2018 10:59:35 -0600 (MDT) Received: from oc8043147753.ibm.com (unknown [9.85.175.5]) by b03ledav002.gho.boulder.ibm.com (Postfix) with ESMTP; Wed, 15 Aug 2018 10:59:35 -0600 (MDT) Subject: Re: [PATCH v9 10/22] s390: vfio-ap: sysfs interfaces to configure adapters To: Cornelia Huck , Tony Krowiak Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.com, kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com, alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com, frankja@linux.ibm.com References: <1534196899-16987-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1534196899-16987-11-git-send-email-akrowiak@linux.vnet.ibm.com> <20180815115242.35a2a1ce.cohuck@redhat.com> From: Tony Krowiak Date: Wed, 15 Aug 2018 12:59:35 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <20180815115242.35a2a1ce.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 18081516-0012-0000-0000-0000169EF8CB X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009550; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01073947; UDB=6.00553401; IPR=6.00853906; MB=3.00022736; MTD=3.00000008; XFM=3.00000015; UTC=2018-08-15 16:59:45 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18081516-0013-0000-0000-0000540D2915 Message-Id: <4bf27c7a-34c6-9160-cdc6-19022b86202b@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-15_06:,, 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 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808150179 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/15/2018 05:52 AM, Cornelia Huck wrote: > On Mon, 13 Aug 2018 17:48:07 -0400 > Tony Krowiak wrote: > >> +/** >> + * assign_adapter_store >> + * >> + * @dev: the matrix device >> + * @attr: a mediated matrix device attribute >> + * @buf: a buffer containing the adapter ID (APID) to be assigned >> + * @count: the number of bytes in @buf >> + * >> + * Parses the APID from @buf and assigns it to the mediated matrix device. >> + * >> + * Returns the number of bytes processed if the APID is valid; otherwise returns >> + * an error. >> + */ >> +static ssize_t assign_adapter_store(struct device *dev, >> + struct device_attribute *attr, >> + const char *buf, size_t count) >> +{ >> + int ret = 0; > You don't need to initialize this to 0, as kstrtoul will set it in any > case. Right you are! Will change it. > >> + unsigned long apid; >> + struct mdev_device *mdev = mdev_from_dev(dev); >> + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); >> + unsigned long max_apid = matrix_mdev->matrix.apm_max; >> + >> + ret = kstrtoul(buf, 0, &apid); >> + if (ret) >> + return ret; >> + if (apid > max_apid) >> + return -EINVAL; >> + >> + /* Set the bit in the AP mask (APM) corresponding to the AP adapter >> + * number (APID). The bits in the mask, from most significant to least >> + * significant bit, correspond to APIDs 0-255. >> + */ >> + mutex_lock(&matrix_dev.lock); >> + >> + ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid); > That function name really is a mouthful :) I don't have any better > suggestions, though. It is, but I think it describes exactly what the function does. > >> + if (ret) >> + goto done; >> + >> + set_bit_inv(apid, matrix_mdev->matrix.apm); >> + >> + ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev); >> + if (ret) >> + goto share_err; >> + >> + ret = count; >> + goto done; >> + >> +share_err: >> + clear_bit_inv(apid, matrix_mdev->matrix.apm); >> +done: >> + mutex_unlock(&matrix_dev.lock); >> + >> + return ret; >> +} >> +static DEVICE_ATTR_WO(assign_adapter); >> + >> +/** >> + * unassign_adapter_store >> + * >> + * @dev: the matrix device >> + * @attr: a mediated matrix device attribute >> + * @buf: a buffer containing the adapter ID (APID) to be assigned >> + * @count: the number of bytes in @buf >> + * >> + * Parses the APID from @buf and unassigns it from the mediated matrix device. >> + * The APID must be a valid value > A valid value, but not necessarily assigned, right? You are correct, if the APID is not assigned, then the corresponding bit will be cleared regardless. In a previous version, the functions failed if the APID is not assigned, but a colleague removed that check. I guess it makes sense given it really does not hurt anything to ask to unassign an APID that isn't assigned to begin with. Would you prefer I update the comment, or do you feel the user should be made aware of an attempt to unassign an APID that is not assigned? > >> + * >> + * Returns the number of bytes processed if the APID is valid; otherwise returns >> + * an error. >> + */ >> +static ssize_t unassign_adapter_store(struct device *dev, >> + struct device_attribute *attr, >> + const char *buf, size_t count) >> +{ >> + int ret; >> + unsigned long apid; >> + struct mdev_device *mdev = mdev_from_dev(dev); >> + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); >> + >> + ret = kstrtoul(buf, 0, &apid); >> + if (ret) >> + return ret; >> + >> + if (apid > matrix_mdev->matrix.apm_max) >> + return -EINVAL; >> + >> + mutex_lock(&matrix_dev.lock); >> + clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm); >> + mutex_unlock(&matrix_dev.lock); >> + >> + return count; >> +} >> +DEVICE_ATTR_WO(unassign_adapter); > In general, looks good to me. That is good news indeed. >