From patchwork Fri Jun 5 21:40:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anthony Krowiak X-Patchwork-Id: 11590651 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D188492A for ; Fri, 5 Jun 2020 21:42:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE4DF2081A for ; Fri, 5 Jun 2020 21:42:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729066AbgFEVma (ORCPT ); Fri, 5 Jun 2020 17:42:30 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:50428 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729071AbgFEVm0 (ORCPT ); Fri, 5 Jun 2020 17:42:26 -0400 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 055LZpZc117290; 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Fri, 05 Jun 2020 21:41:19 +0000 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 055LeHVN8979232 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 5 Jun 2020 21:40:17 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9FE06AC059; Fri, 5 Jun 2020 21:40:17 +0000 (GMT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 33EE4AC065; Fri, 5 Jun 2020 21:40:17 +0000 (GMT) Received: from cpe-172-100-175-116.stny.res.rr.com.com (unknown [9.85.146.208]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP; Fri, 5 Jun 2020 21:40:17 +0000 (GMT) From: Tony Krowiak To: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: freude@linux.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com, mjrosato@linux.ibm.com, pasic@linux.ibm.com, alex.williamson@redhat.com, kwankhede@nvidia.com, fiuczy@linux.ibm.com, Tony Krowiak Subject: [PATCH v8 16/16] s390/vfio-ap: handle probe/remove not due to host AP config changes Date: Fri, 5 Jun 2020 17:40:04 -0400 Message-Id: <20200605214004.14270-17-akrowiak@linux.ibm.com> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200605214004.14270-1-akrowiak@linux.ibm.com> References: <20200605214004.14270-1-akrowiak@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216,18.0.687 definitions=2020-06-05_07:2020-06-04,2020-06-05 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 mlxlogscore=999 cotscore=-2147483648 priorityscore=1501 mlxscore=0 impostorscore=0 adultscore=0 suspectscore=3 malwarescore=0 spamscore=0 bulkscore=0 lowpriorityscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006050157 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org AP queue devices are probed or removed for reasons other than changes to the host AP configuration: * Each queue device associated with a card device will get created and probed when the state of the AP adapter represented by the card device dynamically changes from standby to online. * Each queue device associated with a card device will get removed when the state of the AP adapter to which the queue represented by the queue device dynamically changes from online to standby. * Each queue device associated with a card device will get removed when the type of the AP adapter to which the queue represented by the queue device dynamically changes. * Each queue device associated with a card device will get removed when the status of the queue represented by the queue device changes from operating to check stop. * AP queue devices can be manually bound to or unbound from the vfio_ap device driver by a root user via the sysfs bind/unbind attributes of the driver. In response to a queue device probe or remove that is not the result of a change to the host's AP configuration, if a KVM guest is using the matrix mdev to which the APQN of the queue device is assigned, the vfio_ap device driver must respond accordingly. In an ideal world, the queue corresponding to the queue device being probed would be hot plugged into the guest. Likewise, the queue corresponding to the queue device being removed would be hot unplugged from the guest. Unfortunately, the AP architecture precludes plugging or unplugging individual queues, so let's handle the probe or remove of an AP queue device as follows: Handling Probe -------------- There are two requirements that must be met in order to give a guest access to the queue corresponding to the queue device being probed: * Each APQN derived from the APID of the queue device and the APQIs of the domains already assigned to the guest's AP configuration must reference a queue device bound to the vfio_ap device driver. * Each APQN derived from the APQI of the queue device and the APIDs of the adapters assigned to the guest's AP configuration must reference a queue device bound to the vfio_ap device driver. If the above conditions are met, the APQN will be assigned to the guest's AP configuration and the guest will be given access to the queue. Handling Remove --------------- Since the AP architecture precludes us from taking access to an individual queue from a guest, we are left with the choice of taking access away from either the adapter or the domain to which the queue is connected. Access to the adapter will be taken away because it is likely that most of the time, the remove callback will be invoked because the adapter state has transitioned from online to standby. In such a case, no queue connected to the adapter will be available to access. Signed-off-by: Tony Krowiak --- drivers/s390/crypto/vfio_ap_ops.c | 38 +++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index cfe93ff9cc8c..5ee60dac7ad1 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -1681,6 +1681,15 @@ static void vfio_ap_queue_link_mdev(struct vfio_ap_queue *q) } } +void vfio_ap_mdev_hot_plug_queue(struct vfio_ap_queue *q) +{ + if ((q->matrix_mdev == NULL) || !vfio_ap_mdev_has_crycb(q->matrix_mdev)) + return; + + if (vfio_ap_mdev_config_shadow_apcb(q->matrix_mdev)) + vfio_ap_mdev_commit_shadow_apcb(q->matrix_mdev); +} + int vfio_ap_mdev_probe_queue(struct ap_queue *queue) { struct vfio_ap_queue *q; @@ -1694,11 +1703,35 @@ int vfio_ap_mdev_probe_queue(struct ap_queue *queue) q->apqn = queue->qid; q->saved_isc = VFIO_AP_ISC_INVALID; vfio_ap_queue_link_mdev(q); + /* Make sure we're not in the middle of an AP configuration change. */ + if (!(matrix_dev->flags & AP_MATRIX_CFG_CHG)) + vfio_ap_mdev_hot_plug_queue(q); mutex_unlock(&matrix_dev->lock); return 0; } +void vfio_ap_mdev_hot_unplug_queue(struct vfio_ap_queue *q) +{ + unsigned long apid = AP_QID_CARD(q->apqn); + unsigned long apqi = AP_QID_QUEUE(q->apqn); + + if ((q->matrix_mdev == NULL) || !vfio_ap_mdev_has_crycb(q->matrix_mdev)) + return; + + /* + * If the APQN is assigned to the guest, then let's + * go ahead and unplug the adapter since the + * architecture does not provide a means to unplug + * an individual queue. + */ + if (test_bit_inv(apid, q->matrix_mdev->shadow_apcb.apm) && + test_bit_inv(apqi, q->matrix_mdev->shadow_apcb.aqm)) { + if (vfio_ap_mdev_unassign_guest_apid(q->matrix_mdev, apid)) + vfio_ap_mdev_commit_shadow_apcb(q->matrix_mdev); + } +} + void vfio_ap_mdev_remove_queue(struct ap_queue *queue) { struct vfio_ap_queue *q; @@ -1706,6 +1739,11 @@ void vfio_ap_mdev_remove_queue(struct ap_queue *queue) mutex_lock(&matrix_dev->lock); q = dev_get_drvdata(&queue->ap_dev.device); + + /* Make sure we're not in the middle of an AP configuration change. */ + if (!(matrix_dev->flags & AP_MATRIX_CFG_CHG)) + vfio_ap_mdev_hot_unplug_queue(q); + dev_set_drvdata(&queue->ap_dev.device, NULL); apid = AP_QID_CARD(q->apqn); apqi = AP_QID_QUEUE(q->apqn);