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=-0.8 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 A827AECE561 for ; Mon, 24 Sep 2018 11:49:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5C6FE2145D for ; Mon, 24 Sep 2018 11:49:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5C6FE2145D 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 S1728998AbeIXRvW (ORCPT ); Mon, 24 Sep 2018 13:51:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43214 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727229AbeIXRvV (ORCPT ); Mon, 24 Sep 2018 13:51:21 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D3EB381F09; Mon, 24 Sep 2018 11:49:39 +0000 (UTC) Received: from gondolin (dhcp-192-222.str.redhat.com [10.33.192.222]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2922E84967; Mon, 24 Sep 2018 11:49:34 +0000 (UTC) Date: Mon, 24 Sep 2018 13:49:31 +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 v10 00/26] guest dedicated crypto adapters Message-ID: <20180924134931.6c67a3d2.cohuck@redhat.com> In-Reply-To: <1536781396-13601-1-git-send-email-akrowiak@linux.vnet.ibm.com> References: <1536781396-13601-1-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 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Mon, 24 Sep 2018 11:49:40 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 12 Sep 2018 15:42:50 -0400 Tony Krowiak wrote: > Abstract: > ======== > > On s390, we have cryptographic coprocessor cards, which are modeled on > Linux as devices on the AP bus. Each card can be partitioned into domains > which can be thought of as a set of hardware registers for processing > crypto commands. Crypto commands are sent to a specific domain within a > card is via a queue which is identified as 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) > > 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 > most of the rest. > > 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 > parent node for mdev devices. > > If you now want to give the tuples (4,1) and (4,2), you need to do the > following: > > - Make sure the queues (4,1) and (4,2) belong to vfio_ap (see patches > #5 and #6) > - Create the mediated device. > - Assign card 4 and domains 1 and 2 to the mediated device > - Optionally activate the mediated device. > > QEMU will now simply consume the mediated device and things should work. > > For a complete description of the architecture and concepts underlying > the design, see the Documentation/s390/vfio-ap.txt file included with this > patch set. I did not spot anything major, and if v11 addresses the issues raised by various reviewers I don't see why it should not be merged (interface looks sane). I skipped looking at the vsie stuff, though ;)