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=-17.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,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 8CFB9C63777 for ; Thu, 3 Dec 2020 10:21:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 29A1A20671 for ; Thu, 3 Dec 2020 10:21:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729033AbgLCKUw (ORCPT ); Thu, 3 Dec 2020 05:20:52 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:53243 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726898AbgLCKUw (ORCPT ); Thu, 3 Dec 2020 05:20:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606990765; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=fdoqPowfgaPwgdpg4xdqnBSrmpGIg2cYmWgzjzhfZg8=; b=EBOmkUjuurcdFXdmdMWBeWWNEWOyvDRjbOzOztJq/t1SIE4/J0gfSxfI2sUKr8YCIBN+/W XMEHQ0+TWzfsj3Tvd2r4pyMQeNhoTCP0dIH9J5rKfNVHNhXYYp5fjZhY90fHslxU6msqI9 cVB46jOvmrq9JqEoiFOSE33b8sedG7o= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-294-NznW8gA9Op-k8sBayTMKlw-1; Thu, 03 Dec 2020 05:19:23 -0500 X-MC-Unique: NznW8gA9Op-k8sBayTMKlw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6A4141936B8F; Thu, 3 Dec 2020 10:19:17 +0000 (UTC) Received: from gondolin (ovpn-113-106.ams2.redhat.com [10.36.113.106]) by smtp.corp.redhat.com (Postfix) with ESMTP id BE6E35D6AC; Thu, 3 Dec 2020 10:19:09 +0000 (UTC) Date: Thu, 3 Dec 2020 11:19:07 +0100 From: Cornelia Huck To: Tony Krowiak Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, borntraeger@de.ibm.com, pasic@linux.ibm.com, alex.williamson@redhat.com, kwankhede@nvidia.com, david@redhat.com Subject: Re: [PATCH] s390/vfio-ap: Clean up vfio_ap resources when KVM pointer invalidated Message-ID: <20201203111907.72a89884.cohuck@redhat.com> In-Reply-To: <20201202234101.32169-1-akrowiak@linux.ibm.com> References: <20201202234101.32169-1-akrowiak@linux.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 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2 Dec 2020 18:41:01 -0500 Tony Krowiak wrote: > The vfio_ap device driver registers a group notifier with VFIO when the > file descriptor for a VFIO mediated device for a KVM guest is opened to > receive notification that the KVM pointer is set (VFIO_GROUP_NOTIFY_SET_KVM > event). When the KVM pointer is set, the vfio_ap driver stashes the pointer > and calls the kvm_get_kvm() function to increment its reference counter. > When the notifier is called to make notification that the KVM pointer has > been set to NULL, the driver should clean up any resources associated with > the KVM pointer and decrement its reference counter. The current > implementation does not take care of this clean up. > > Signed-off-by: Tony Krowiak > --- > drivers/s390/crypto/vfio_ap_ops.c | 21 +++++++++++++-------- > 1 file changed, 13 insertions(+), 8 deletions(-) > > diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c > index e0bde8518745..eeb9c9130756 100644 > --- a/drivers/s390/crypto/vfio_ap_ops.c > +++ b/drivers/s390/crypto/vfio_ap_ops.c > @@ -1083,6 +1083,17 @@ static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb, > return NOTIFY_DONE; > } > > +static void vfio_ap_mdev_put_kvm(struct ap_matrix_mdev *matrix_mdev) > +{ > + if (matrix_mdev->kvm) { > + kvm_arch_crypto_clear_masks(matrix_mdev->kvm); > + matrix_mdev->kvm->arch.crypto.pqap_hook = NULL; > + vfio_ap_mdev_reset_queues(matrix_mdev->mdev); > + kvm_put_kvm(matrix_mdev->kvm); > + matrix_mdev->kvm = NULL; > + } > +} > + > static int vfio_ap_mdev_group_notifier(struct notifier_block *nb, > unsigned long action, void *data) > { > @@ -1095,7 +1106,7 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb, > matrix_mdev = container_of(nb, struct ap_matrix_mdev, group_notifier); > > if (!data) { > - matrix_mdev->kvm = NULL; > + vfio_ap_mdev_put_kvm(matrix_mdev); Hm. I'm wondering whether you need to hold the maxtrix_dev lock here as well? > return NOTIFY_OK; > } > > @@ -1222,13 +1233,7 @@ static void vfio_ap_mdev_release(struct mdev_device *mdev) > struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); > > mutex_lock(&matrix_dev->lock); > - if (matrix_mdev->kvm) { > - kvm_arch_crypto_clear_masks(matrix_mdev->kvm); > - matrix_mdev->kvm->arch.crypto.pqap_hook = NULL; > - vfio_ap_mdev_reset_queues(mdev); > - kvm_put_kvm(matrix_mdev->kvm); > - matrix_mdev->kvm = NULL; > - } > + vfio_ap_mdev_put_kvm(matrix_mdev); > mutex_unlock(&matrix_dev->lock); > > vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,