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 5F06BC46464 for ; Mon, 13 Aug 2018 06:58:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0035921834 for ; Mon, 13 Aug 2018 06:58:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0035921834 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 S1728431AbeHMJjA (ORCPT ); Mon, 13 Aug 2018 05:39:00 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50276 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726345AbeHMJjA (ORCPT ); Mon, 13 Aug 2018 05:39:00 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1543B7C6A9; Mon, 13 Aug 2018 06:58:05 +0000 (UTC) Received: from gondolin (ovpn-116-236.ams2.redhat.com [10.36.116.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7C99E42228; Mon, 13 Aug 2018 06:57:59 +0000 (UTC) Date: Mon, 13 Aug 2018 08:57:55 +0200 From: Cornelia Huck To: Tony Krowiak Cc: Pierre Morel , Tony Krowiak , 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 Subject: Re: [PATCH v8 17/22] s390: vfio-ap: zeroize the AP queues. Message-ID: <20180813085755.6ad962fb.cohuck@redhat.com> In-Reply-To: <14983b58-f53b-8bd9-179e-29b9a69c21d8@linux.ibm.com> References: <1533739472-7172-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1533739472-7172-18-git-send-email-akrowiak@linux.vnet.ibm.com> <20180810111445.015fcf2a.cohuck@redhat.com> <20180810131648.4fab1d7a.cohuck@redhat.com> <14983b58-f53b-8bd9-179e-29b9a69c21d8@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 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 13 Aug 2018 06:58:05 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 13 Aug 2018 06:58:05 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.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 Fri, 10 Aug 2018 12:24:47 -0400 Tony Krowiak wrote: > On 08/10/2018 07:16 AM, Cornelia Huck wrote: > > On Fri, 10 Aug 2018 12:49:08 +0200 > > Pierre Morel wrote: > > > >> On 10/08/2018 11:14, Cornelia Huck wrote: > >>> On Wed, 8 Aug 2018 10:44:27 -0400 > >>> Tony Krowiak wrote: > >>> > >>>> From: Tony Krowiak > >>>> > >>>> Let's call PAPQ(ZAPQ) to zeroize a queue: > >>>> > >>>> * For each queue configured for a mediated matrix device > >>>> when it is released. > >>>> > >>>> Zeroizing a queue resets the queue, clears all pending > >>>> messages for the queue entries and disables adapter interruptions > >>>> associated with the queue. > >>>> > >>>> Signed-off-by: Tony Krowiak > >>>> Reviewed-by: Halil Pasic > >>>> Tested-by: Michael Mueller > >>>> Tested-by: Farhan Ali > >>>> Signed-off-by: Christian Borntraeger > >>>> --- > >>>> drivers/s390/crypto/vfio_ap_ops.c | 29 ++++++++++++++++++++++++++++- > >>>> drivers/s390/crypto/vfio_ap_private.h | 25 +++++++++++++++++++++++++ > >>>> 2 files changed, 53 insertions(+), 1 deletions(-) > >>>> > >>>> @@ -788,7 +812,10 @@ static void vfio_ap_mdev_release(struct mdev_device *mdev) > >>>> { > >>>> struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); > >>>> > >>>> - kvm_arch_crypto_clear_masks(matrix_mdev->kvm); > >>>> + if (matrix_mdev->kvm) > >>>> + kvm_arch_crypto_clear_masks(matrix_mdev->kvm); > >>> Confused. Why is the check for matrix_mdev->kvm added here? > >> When using the KVM notifier we can get two notifications: > >> -> KVM is here / is comming > >> -> KVM is not here / disappearing > >> > >> In the first case we initialize matrix_mdev->kvm with a pointer to KVM > >> In the second case we nullify the pointer. > >> > >> During the open of the mediated device, the guest should have been started > >> or we refuse to start. > >> > >> During the close of the mediated device, the guest should be there, but > >> we have no certitude that the guest did not disappear before the VFIO > >> file being closed. > >> Since we do not allow multiple guests using the same mediated device > >> this case should not happen with QEMU. But I am not sure that > >> a rogue user program could not stop KVM before closing the VFIO > >> mediated device. > > I'm not sure why the check is introduced in this patch, though. But > > maybe I just need weekend :) > > Good catch, it belongs in patch 15 where the function is introduced. > Is that the only reason for your objection? Yes, this is what confused me. Moving this to patch 15 sounds like a good idea :) > > > > >> Maybe Alex can confirm this point, if not we can remove the test. > >