From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752803AbdJ3TEr (ORCPT ); Mon, 30 Oct 2017 15:04:47 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:57960 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751402AbdJ3TEp (ORCPT ); Mon, 30 Oct 2017 15:04:45 -0400 Subject: Re: [RFC 00/19] KVM: s390/crypto/vfio: guest dedicated crypto adapters To: Christian Borntraeger , Cornelia Huck 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, 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, qemu-s390x@nongnu.org, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, qemu-devel , Erik Skultety , "Daniel P. Berrange" References: <1507916344-3896-1-git-send-email-akrowiak@linux.vnet.ibm.com> <20171029121122.122412ca.cohuck@redhat.com> From: Tony Krowiak Date: Mon, 30 Oct 2017 15:04:35 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 17103019-0028-0000-0000-000008934C96 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007982; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000239; SDB=6.00938750; UDB=6.00473219; IPR=6.00719011; BA=6.00005663; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00017795; XFM=3.00000015; UTC=2017-10-30 19:04:43 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17103019-0029-0000-0000-000038248FAD Message-Id: <61214ce9-c3de-44b7-2a53-585f3acb16fe@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-10-30_06:,, 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 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710300253 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/30/2017 04:57 AM, Christian Borntraeger wrote: > adding qemu devel and add Daniel and Erik from libvirt to keep them in the loop. > > On 10/29/2017 12:11 PM, Cornelia Huck wrote: >> On Fri, 13 Oct 2017 13:38:45 -0400 >> Tony Krowiak wrote: >> >>> Tony Krowiak (19): >>> KVM: s390: SIE considerations for AP Queue virtualization >>> KVM: s390: refactor crypto initialization >>> s390/zcrypt: new AP matrix bus >>> s390/zcrypt: create an AP matrix device on the AP matrix bus >>> s390/zcrypt: base implementation of AP matrix device driver >>> s390/zcrypt: register matrix device with VFIO mediated device >>> framework >>> KVM: s390: introduce AP matrix configuration interface >>> s390/zcrypt: support for assigning adapters to matrix mdev >>> s390/zcrypt: validate adapter assignment >>> s390/zcrypt: sysfs interfaces supporting AP domain assignment >>> s390/zcrypt: validate domain assignment >>> s390/zcrypt: sysfs support for control domain assignment >>> s390/zcrypt: validate control domain assignment >>> KVM: s390: Connect the AP mediated matrix device to KVM >>> s390/zcrypt: introduce ioctl access to VFIO AP Matrix driver >>> KVM: s390: interface to configure KVM guest's AP matrix >>> KVM: s390: validate input to AP matrix config interface >>> KVM: s390: New ioctl to configure KVM guest's AP matrix >>> s390/facilities: enable AP facilities needed by guest >> I'll try to summarize all of this in my own words, both to make sure I >> understand the design correctly and to give others a different view on >> this. >> >> [I'm completely disregarding control domains here.] >> >> On s390, we have cryptographic coprocessor cards, which are modeled on >> Linux as devices on the AP bus. There's also a concept called domains, >> which means an individual queue of a crypto device is basically a >> (card,domain) tuple. We model this something like the following >> (assuming we have access to cards 3 and 4 and domains 1 and 2): >> >> AP -> card3 -> queue (3,1) >> -> queue (3,2) >> -> card4 -> queue (4,1) >> -> queue (4,2) >> >> (The AP bus is a bit different for backwards compat.) >> >> If we want to virtualize this, we can use a feature provided by the >> hardware. We basically attach a satellite control block to our main >> hardware virtualization control block and the hardware takes care of >> (mostly) everything. >> >> For this control block, we don't specify explicit tuples, but a list of >> cards and a list of domains. The guest will get access to the cross >> product. >> >> Because of this, we need to take care that the lists provided to >> different guests don't overlap; i.e., we need to enforce sane >> configurations. Otherwise, one guest may get access to things like >> secret keys for another guest. >> >> The idea of this patch set is to introduce a new device, the matrix >> device. This matrix device hangs off a different root and acts as the >> node where mdev devices hang off. >> >> If you now want to give the tuples (4,1) and (4,2), you need to do the >> following: >> >> - Unbind the (4,1) and (4,2) tuples from their ap bus driver. >> - Bind the (4,1) and (4,2) tuples to the ap matrix driver. >> - Create the mediated device. >> - Assign card 4 and domains 1 and 2. >> >> QEMU will now simply consume the mediated device and things should work. >> > This is probably the shortest possible summary I can imagine. > Tony can you double check if it matches your understanding as well? This is a concise and accurate summary. >