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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=unavailable 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 04622C43381 for ; Fri, 8 Mar 2019 22:32:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D138A20643 for ; Fri, 8 Mar 2019 22:32:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726456AbfCHWco (ORCPT ); Fri, 8 Mar 2019 17:32:44 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34046 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726286AbfCHWco (ORCPT ); Fri, 8 Mar 2019 17:32:44 -0500 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 70D0A58E51; Fri, 8 Mar 2019 22:32:44 +0000 (UTC) Received: from x1.home (ovpn-116-24.phx2.redhat.com [10.3.116.24]) by smtp.corp.redhat.com (Postfix) with ESMTP id 67B7160BE7; Fri, 8 Mar 2019 22:32:43 +0000 (UTC) Date: Fri, 8 Mar 2019 15:32:43 -0700 From: Alex Williamson To: Parav Pandit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, michal.lkml@markovi.net, davem@davemloft.net, gregkh@linuxfoundation.org, jiri@mellanox.com, kwankhede@nvidia.com, vuhuong@mellanox.com, yuvalav@mellanox.com, jakub.kicinski@netronome.com, kvm@vger.kernel.org Subject: Re: [RFC net-next v1 1/3] vfio/mdev: Inherit dma masks of parent device Message-ID: <20190308153243.49a31e1e@x1.home> In-Reply-To: <1552082876-60228-2-git-send-email-parav@mellanox.com> References: <1552082876-60228-1-git-send-email-parav@mellanox.com> <1552082876-60228-2-git-send-email-parav@mellanox.com> Organization: Red Hat 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 [10.5.110.39]); Fri, 08 Mar 2019 22:32:44 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, 8 Mar 2019 16:07:54 -0600 Parav Pandit wrote: > Inherit dma mask of parent device in child mdev devices, so that > protocol stack can use right dma mask while doing dma mappings. > > Signed-off-by: Parav Pandit > --- > drivers/vfio/mdev/mdev_core.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c > index 0212f0e..9b8bdc9 100644 > --- a/drivers/vfio/mdev/mdev_core.c > +++ b/drivers/vfio/mdev/mdev_core.c > @@ -315,6 +315,10 @@ int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid) > mdev->dev.parent = dev; > mdev->dev.bus = &mdev_bus_type; > mdev->dev.release = mdev_device_release; > + mdev->dev.dma_mask = dev->dma_mask; > + mdev->dev.dma_parms = dev->dma_parms; > + mdev->dev.coherent_dma_mask = dev->coherent_dma_mask; > + > dev_set_name(&mdev->dev, "%pUl", uuid.b); > > ret = device_register(&mdev->dev); This seems like a rather large assumption and none of the existing mdev drivers even make use of DMA ops. Why shouldn't this be done in mdev_parent_ops.create? Thanks, Alex