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=unavailable 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 D33BFC282DA for ; Wed, 17 Apr 2019 15:38:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A1BFF20674 for ; Wed, 17 Apr 2019 15:38:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732686AbfDQPiK (ORCPT ); Wed, 17 Apr 2019 11:38:10 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:55390 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729940AbfDQPiI (ORCPT ); Wed, 17 Apr 2019 11:38:08 -0400 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3HFUMAY009458 for ; Wed, 17 Apr 2019 11:38:08 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2rx5s3ussp-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 17 Apr 2019 11:38:07 -0400 Received: from localhost by e06smtp04.uk.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, 17 Apr 2019 16:38:03 +0100 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x3HFc18J59506816 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 17 Apr 2019 15:38:01 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 86278A4051; Wed, 17 Apr 2019 15:38:01 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 00706A404D; Wed, 17 Apr 2019 15:38:01 +0000 (GMT) Received: from oc2783563651 (unknown [9.152.99.136]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 17 Apr 2019 15:38:00 +0000 (GMT) Date: Wed, 17 Apr 2019 17:37:59 +0200 From: Halil Pasic To: Tony Krowiak Cc: Cornelia Huck , Harald Freudenberger , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Reinhard Buendgen , borntraeger@de.ibm.com, frankja@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, pmorel@linux.ibm.com, alex.williamson@redhat.com, kwankhede@nvidia.com Subject: Re: [PATCH 1/7] s390: zcrypt: driver callback to indicate resource in use In-Reply-To: <0c7dbcd5-295c-8dc1-7223-01866694ebc4@linux.ibm.com> References: <1555016604-2008-1-git-send-email-akrowiak@linux.ibm.com> <1555016604-2008-2-git-send-email-akrowiak@linux.ibm.com> <223c82c7-6a75-7209-3652-c2341c83878f@linux.ibm.com> <20190412114313.0156c01b.cohuck@redhat.com> <89f09e58-eab6-94d4-c5aa-937162d60744@linux.ibm.com> <20190415115030.1df61182.cohuck@redhat.com> <3d762e51-7210-529f-61de-98d80689bff6@linux.ibm.com> <20190415205950.7655cee3@oc2783563651> <0c7dbcd5-295c-8dc1-7223-01866694ebc4@linux.ibm.com> Organization: IBM X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19041715-0016-0000-0000-0000026FECE8 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19041715-0017-0000-0000-000032CC3F76 Message-Id: <20190417173759.3a7d20d7@oc2783563651> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-04-17_07:,, 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=642 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904170104 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, 15 Apr 2019 18:43:24 -0400 Tony Krowiak wrote: > On 4/15/19 2:59 PM, Halil Pasic wrote: > > On Mon, 15 Apr 2019 12:51:23 -0400 > > Tony Krowiak wrote: > > > >> Having said that, I understand your concern about a driver hogging > >> resources. I think I can provide a solution that serves both the > >> purpose of preventing problems associated with accidental removal > >> of AP resources as well as allowing root to remove them > >> forcefully. I'll work on that for v2. > > > > Can you tell us some more about this solution? Should we stop reviewing > > v1 because v2 is going to be different anyway? > > Patch 1 and 2 will be removed. There will not be a major design change > between these patches and v2. In order to avoid a long explanation of > my proposed changes, I'd prefer to state that the patch set will > establish and enforce the following rules: > > 1. An APQN can be assigned to an mdev device iff it is NOT > reserved for use by a zcrypt driver and is not assigned to > another mdev device. > > 2. Once an APQN is assigned to an mdev device, it will remain > assigned until it is explicitly unassigned. > > 3. A queue's APQN can be set in the guest's CRYCB iff the APQN is > assigned to the mdev device used by the guest; however, if the > queue is also in the host configuration (i.e., online), it MUST > also be bound to the vfio_ap device driver. > > 4. When a queue is bound to the vfio_ap driver and its APQN > is assigned to an mdev device in use by a guest, the guest will > be given access to the queue. > > 5. When a queue is unbound from the vfio_ap driver and its APQN > is assigned to an mdev device in use by the guest, access to > the card containing the queue will be removed from the guest. > Keep in mind that we can not deny access to a specific queue > due to the architecture (i.e., clearing a bit in the AQM > removes access to the queue for all adapters) > > 6. When an adapter is assigned to an mdev device that is in use > by a guest, the guest will be given access to the adapter. > > 7. When an adapter is unassigned from an mdev device that is in use > by a guest, access to the adapter will removed from the guest. > > 8. When a domain is assigned to an mdev device that is in use > by a guest, the guest will be given access to the domain. > > 9. When a domain is unassigned from an mdev device that is in use > by a guest, access to the domain will removed from the guest. > Based on our off-the-list chat and this list I think I know where are you heading :). I think it's actually the design that I currently prefer the most. But in that case, it may be wise to touch base with Reinhard -- AFAIR he was the strongest proponent of the 'do not let a[pq]mask changes take away queues from guests' design. Regards, Halil