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=-0.9 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 25578C04A6B for ; Wed, 8 May 2019 21:08:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF0EC2173C for ; Wed, 8 May 2019 21:08:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726591AbfEHVIV (ORCPT ); Wed, 8 May 2019 17:08:21 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:55718 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726709AbfEHVIU (ORCPT ); Wed, 8 May 2019 17:08:20 -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 x48KpnU3031272 for ; Wed, 8 May 2019 17:08:19 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2sc54ecdsq-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 08 May 2019 17:08:19 -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, 8 May 2019 22:08:13 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x48L8CtC48038038 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 8 May 2019 21:08:12 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 598C84C04E; Wed, 8 May 2019 21:08:12 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 90B9F4C044; Wed, 8 May 2019 21:08:11 +0000 (GMT) Received: from oc2783563651 (unknown [9.145.71.200]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 8 May 2019 21:08:11 +0000 (GMT) Date: Wed, 8 May 2019 23:08:09 +0200 From: Halil Pasic To: Sebastian Ott Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, Cornelia Huck , Martin Schwidefsky , 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 Subject: Re: [PATCH 06/10] s390/cio: add basic protected virtualization support In-Reply-To: References: <20190426183245.37939-1-pasic@linux.ibm.com> <20190426183245.37939-7-pasic@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: 19050821-0016-0000-0000-00000279B159 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19050821-0017-0000-0000-000032D662B1 Message-Id: <20190508230809.6b0faaf7.pasic@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-08_12:,, 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=882 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905080127 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, 8 May 2019 15:46:42 +0200 (CEST) Sebastian Ott wrote: > > On Fri, 26 Apr 2019, Halil Pasic wrote: > > static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch) > > { > [..] > > + cdev->private = kzalloc(sizeof(struct ccw_device_private), > > + GFP_KERNEL | GFP_DMA); > > Do we still need GFP_DMA here (since we now have cdev->private->dma_area)? > We probably do not. I kept it GFP_DMA to keep changes to the minimum. Should changing this in your opinion be a part of this patch? > > @@ -1062,6 +1082,14 @@ static int io_subchannel_probe(struct subchannel *sch) > > if (!io_priv) > > goto out_schedule; > > > > + io_priv->dma_area = dma_alloc_coherent(&sch->dev, > > + sizeof(*io_priv->dma_area), > > + &io_priv->dma_area_dma, GFP_KERNEL); > > This needs GFP_DMA. Christoph already answered this one. Thanks Christoph! > You use a genpool for ccw_private->dma and not for iopriv->dma - looks > kinda inconsistent. > Please have a look at patch #9. A virtio-ccw device uses the genpool of it's ccw device (the pool from which ccw_private->dma is allicated) for the ccw stuff it needs to do. AFAICT for a subchannel device and its API all the DMA memory we need is iopriv->dma. So my thought was constructing a genpool for that would be an overkill. Are you comfortable with this answer, or should we change something? Regards, Halil