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 11854C4321D for ; Wed, 15 Aug 2018 16:08:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 918B521477 for ; Wed, 15 Aug 2018 16:08:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 918B521477 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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 S1729546AbeHOTBF (ORCPT ); Wed, 15 Aug 2018 15:01:05 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:34274 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729347AbeHOTBF (ORCPT ); Wed, 15 Aug 2018 15:01:05 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C9B434021FC2; Wed, 15 Aug 2018 16:08:19 +0000 (UTC) Received: from gondolin (dhcp-192-222.str.redhat.com [10.33.192.222]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5FE452026D7E; Wed, 15 Aug 2018 16:08:16 +0000 (UTC) Date: Wed, 15 Aug 2018 18:08:14 +0200 From: Cornelia Huck To: 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, Tony Krowiak Subject: Re: [PATCH v9 15/22] s390: vfio-ap: implement mediated device open callback Message-ID: <20180815180814.5985e3f0.cohuck@redhat.com> In-Reply-To: <1534196899-16987-16-git-send-email-akrowiak@linux.vnet.ibm.com> References: <1534196899-16987-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1534196899-16987-16-git-send-email-akrowiak@linux.vnet.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Wed, 15 Aug 2018 16:08:19 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Wed, 15 Aug 2018 16:08:19 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'cohuck@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 13 Aug 2018 17:48:12 -0400 Tony Krowiak wrote: > From: Tony Krowiak > > Implements the open callback on the mediated matrix device. > The function registers a group notifier to receive notification > of the VFIO_GROUP_NOTIFY_SET_KVM event. When notified, > the vfio_ap device driver will get access to the guest's > kvm structure. The open callback must ensure that only one > mediated device shall be opened per guest. > > Signed-off-by: Tony Krowiak > Acked-by: Halil Pasic > Tested-by: Michael Mueller > Tested-by: Farhan Ali > Tested-by: Pierre Morel > Acked-by: Pierre Morel > Signed-off-by: Christian Borntraeger > --- > drivers/s390/crypto/vfio_ap_ops.c | 174 ++++++++++++++++++++++++++++++++- > drivers/s390/crypto/vfio_ap_private.h | 2 + > 2 files changed, 175 insertions(+), 1 deletions(-) > @@ -602,7 +633,6 @@ static ssize_t matrix_show(struct device *dev, struct device_attribute *attr, > } > DEVICE_ATTR_RO(matrix); > > - Nit: whitespace change > static struct attribute *vfio_ap_mdev_attrs[] = { > &dev_attr_assign_adapter.attr, > &dev_attr_unassign_adapter.attr, (...) > +/** > + * vfio_ap_mdev_open_once > + * > + * @matrix_mdev: a mediated matrix device > + * > + * Return 0 if no other mediated matrix device has been opened for the > + * KVM guest assigned to @matrix_mdev; otherwise, returns an error. > + */ > +static int vfio_ap_mdev_open_once(struct ap_matrix_mdev *matrix_mdev, > + struct kvm *kvm) You're passing kvm in here, but do not use it. > +{ > + struct ap_matrix_mdev *m; > + > + mutex_lock(&matrix_dev.lock); > + > + list_for_each_entry(m, &matrix_dev.mdev_list, list) { > + if ((m != matrix_mdev) && (m->kvm == matrix_mdev->kvm)) { If you used it here instead of matrix_mdev->kvm... > + mutex_unlock(&matrix_dev.lock); > + return -EPERM; > + } > + } > + > + mutex_unlock(&matrix_dev.lock); > + > + return 0; > +} > + > +static int vfio_ap_mdev_group_notifier(struct notifier_block *nb, > + unsigned long action, void *data) > +{ > + int ret; > + struct ap_matrix_mdev *matrix_mdev; > + > + if (action != VFIO_GROUP_NOTIFY_SET_KVM) > + return NOTIFY_OK; > + > + matrix_mdev = container_of(nb, struct ap_matrix_mdev, group_notifier); > + > + matrix_mdev->kvm = data; > + if (data == NULL) > + return NOTIFY_OK; > + > + ret = vfio_ap_mdev_open_once(matrix_mdev, data); ...you could move this up to before overwriting matrix_mdev->kvm and bailing out when the check failed, which makes more sense to me. > + if (ret) > + return ret; > + > + ret = kvm_ap_validate_crypto_setup(matrix_mdev->kvm); > + if (ret) > + return ret; It probably makes more sense to return NOTIFY_DONE in the error case (NOTIFY_BAD does not sound like a good idea as it would stop processing the notifier chain). > + > + vfio_ap_mdev_copy_masks(matrix_mdev); > + > + return NOTIFY_OK; > +} Otherwise, looks sane.