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_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 F32FDC04AAF for ; Thu, 16 May 2019 13:42:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CCBB120862 for ; Thu, 16 May 2019 13:42:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727533AbfEPNm4 (ORCPT ); Thu, 16 May 2019 09:42:56 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:37006 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726736AbfEPNmz (ORCPT ); Thu, 16 May 2019 09:42:55 -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 x4GDYjar100788 for ; Thu, 16 May 2019 09:42:54 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2sh7edd1hp-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 16 May 2019 09:42:54 -0400 Received: from localhost by e06smtp03.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) Thu, 16 May 2019 14:42:49 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4GDgld519726486 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 May 2019 13:42:47 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AF78352057; Thu, 16 May 2019 13:42:47 +0000 (GMT) Received: from oc2783563651 (unknown [9.145.159.11]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id D2E7C5204E; Thu, 16 May 2019 13:42:46 +0000 (GMT) Date: Thu, 16 May 2019 15:42:45 +0200 From: Halil Pasic To: Cornelia Huck Cc: "Jason J. Herne" , kvm@vger.kernel.org, linux-s390@vger.kernel.org, Martin Schwidefsky , Sebastian Ott , virtualization@lists.linux-foundation.org, "Michael S. Tsirkin" , Christoph Hellwig , Thomas Huth , Christian Borntraeger , Viktor Mihajlovski , Vasily Gorbik , Janosch Frank , Claudio Imbrenda , Farhan Ali , Eric Farman , Michael Mueller Subject: Re: [PATCH 06/10] s390/cio: add basic protected virtualization support In-Reply-To: <20190516083228.0cc5b489.cohuck@redhat.com> References: <20190426183245.37939-1-pasic@linux.ibm.com> <20190426183245.37939-7-pasic@linux.ibm.com> <20190513114136.783c851c.cohuck@redhat.com> <20190515230817.2f8a8a5d.pasic@linux.ibm.com> <20190516083228.0cc5b489.cohuck@redhat.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: 19051613-0012-0000-0000-0000031C5CC0 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19051613-0013-0000-0000-00002154FE5E Message-Id: <20190516154245.4a0a84f7.pasic@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-16_11:,, 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=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905160091 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, 16 May 2019 08:32:28 +0200 Cornelia Huck wrote: > On Wed, 15 May 2019 23:08:17 +0200 > Halil Pasic wrote: > > > On Tue, 14 May 2019 10:47:34 -0400 > > "Jason J. Herne" wrote: > > > > Are we > > > worried that virtio data structures are going to be a burden on the 31-bit address space? > > > > > > > > > > That is a good question I can not answer. Since it is currently at least > > a page per queue (because we use dma direct, right Mimu?), I am concerned > > about this. > > > > Connie, what is your opinion? > > Yes, running into problems there was one of my motivations for my > question. I guess it depends on the number of devices and how many > queues they use. The problem is that it affects not only protected virt > guests, but all guests. > Unless things are about to change only devices that have VIRTIO_F_IOMMU_PLATFORM are affected. So it does not necessarily affect not protected virt guests. (With prot virt we have to use VIRTIO_F_IOMMU_PLATFORM.) If it were not like this, I would be much more worried. @Mimu: Could you please discuss this problem with the team? It might be worth considering to go back to the design of the RFC (i.e. cio/ccw stuff allocated from a common cio dma pool which gives you 31 bit addressable memory, and 64 bit dma mask for a ccw device of a virtio device). Regards, Halil