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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 B1481C432C0 for ; Tue, 3 Dec 2019 04:07:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9023820665 for ; Tue, 3 Dec 2019 04:07:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726845AbfLCEHq (ORCPT ); Mon, 2 Dec 2019 23:07:46 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:16826 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726327AbfLCEHp (ORCPT ); Mon, 2 Dec 2019 23:07:45 -0500 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xB346s4h095707 for ; Mon, 2 Dec 2019 23:07:45 -0500 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wnehxjn15-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 02 Dec 2019 23:07:44 -0500 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) Tue, 3 Dec 2019 04:07:38 -0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xB346v4S46596372 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 3 Dec 2019 04:06:57 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E66F8A4051; Tue, 3 Dec 2019 04:07:37 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 16F53A404D; Tue, 3 Dec 2019 04:07:34 +0000 (GMT) Received: from oc0525413822.ibm.com (unknown [9.85.173.229]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 3 Dec 2019 04:07:33 +0000 (GMT) Date: Mon, 2 Dec 2019 20:07:31 -0800 From: Ram Pai To: Alexey Kardashevskiy Cc: linuxppc-dev@lists.ozlabs.org, mpe@ellerman.id.au, benh@kernel.crashing.org, david@gibson.dropbear.id.au, paulus@ozlabs.org, mdroth@linux.vnet.ibm.com, hch@lst.de, andmike@us.ibm.com, sukadev@linux.vnet.ibm.com, mst@redhat.com, ram.n.pai@gmail.com, cai@lca.pw, tglx@linutronix.de, bauerman@linux.ibm.com, linux-kernel@vger.kernel.org Reply-To: Ram Pai References: <1575269124-17885-1-git-send-email-linuxram@us.ibm.com> <1575269124-17885-2-git-send-email-linuxram@us.ibm.com> <1575269124-17885-3-git-send-email-linuxram@us.ibm.com> <58b08d09-aaf8-5659-c4e8-c502c508f35c@ozlabs.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <58b08d09-aaf8-5659-c4e8-c502c508f35c@ozlabs.ru> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 19120304-0012-0000-0000-000003701489 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19120304-0013-0000-0000-000021ABCEC5 Message-Id: <20191203040731.GC12354@oc0525413822.ibm.com> Subject: RE: [PATCH v4 2/2] powerpc/pseries/iommu: Use dma_iommu_ops for Secure VMs aswell. X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-12-02_06:2019-11-29,2019-12-02 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 phishscore=0 spamscore=0 adultscore=0 malwarescore=0 bulkscore=0 suspectscore=18 impostorscore=0 mlxlogscore=999 priorityscore=1501 mlxscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912030035 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 03, 2019 at 11:58:18AM +1100, Alexey Kardashevskiy wrote: > > > On 02/12/2019 17:45, Ram Pai wrote: > > Commit edea902c1c1e ("powerpc/pseries/iommu: Don't use dma_iommu_ops on > > secure guests") > > disabled dma_iommu_ops path, for secure VMs. The rationale for disabling > > the dma_iommu_ops path, was to use the dma_direct path, since it had > > inbuilt support for bounce-buffering through SWIOTLB. > > > > However dma_iommu_ops is functionally much richer. Depending on the > > capabilities of the platform, it can handle direct DMA; with or without > > bounce buffering, and it can handle indirect DMA. Hence its better to > > leverage the richer functionality supported by dma_iommu_ops. > > What exactly do we leverage after applying this patch? afaict things are > going to work in exact same old way with this applied, no? Thanks, Yes. You got it right. Another way of saying this is, it reverts the changes. RP