From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: Re: [RFC net-next v1 1/3] vfio/mdev: Inherit dma masks of parent device Date: Fri, 8 Mar 2019 15:32:43 -0700 Message-ID: <20190308153243.49a31e1e@x1.home> References: <1552082876-60228-1-git-send-email-parav@mellanox.com> <1552082876-60228-2-git-send-email-parav@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 To: Parav Pandit Return-path: In-Reply-To: <1552082876-60228-2-git-send-email-parav@mellanox.com> Sender: netdev-owner@vger.kernel.org List-Id: kvm.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