From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933320AbcETIhj (ORCPT ); Fri, 20 May 2016 04:37:39 -0400 Received: from mail-pf0-f193.google.com ([209.85.192.193]:36487 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933117AbcETIgm (ORCPT ); Fri, 20 May 2016 04:36:42 -0400 Date: Fri, 20 May 2016 16:36:30 +0800 From: Peng Fan To: Baptiste Reynal Cc: Eric Auger , Alex Williamson , "open list:VFIO DRIVER" , open list Subject: Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put Message-ID: <20160520083627.GA23014@linux-7smt.suse> References: <1462788103-19906-1-git-send-email-van.freenix@gmail.com> <20160509093238.3901f0b7@t450s.home> <20160510074025.GA1064@linux-7smt.suse> <20160519150149.7a8b80ba@ul30vt.home> <573EC3A8.4050008@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Fri, May 20, 2016 at 10:20:32AM +0200, Baptiste Reynal wrote: >Hi, > >On Fri, May 20, 2016 at 9:58 AM, Eric Auger wrote: >> >> Hi, >> On 05/19/2016 11:01 PM, Alex Williamson wrote: >> > On Tue, 10 May 2016 15:40:28 +0800 >> > Peng Fan wrote: >> > >> >> Hi Alex, >> >> >> >> On Mon, May 09, 2016 at 09:32:38AM -0600, Alex Williamson wrote: >> >>> On Mon, 9 May 2016 18:01:43 +0800 >> >>> Peng Fan wrote: >> >>> >> >>>> Use vfio_iommu_group_get and vfio_iommu_group_put, but not >> >>>> iommu_group_get or iommu_group_put. >> >>> >> >>> I assume you're trying to duplicate the vfio_pci changes from commit >> >>> 03a76b60f8ba to enable no-iommu mode. That would be really relevant >> >>> information for the commit log. >> >> >> >> This is not to support non-iommu for vfio platform. I just think >> >> vfio_iommu_group_get/put is vfio core API and should be used by >> >> vfio-pci and vfio-platform. >> > >> > Hi Peng, >> > >> > I suppose I would consider this an optional part of the internal vfio >> > API, it's only real purpose it to provide the ability to create fake >> > groups which are only used for no-iommu. It's perfectly legitimate to >> > use iommu_group_get/put if there is no desire to enable no-iommu. >> > Baptiste, Eric, do you have an opinion whether enabling no-iommu in >> > vfio/platform is something we should do? Thanks, >> I think it would make sense to introduce that no-iommu feature for >> vfio-platform because it allows potential users to get familiar with >> VFIO platform without having the proper HW. I also thought the primary >> purpose of this patch was to introduce that support. Yeah. Initially I would like to try vfio on my i.MX6/7 boards which does not have HW iommu. I am new to this, so just wrote this simple patch when I was reading the source code. > >Since safety issues have already been addressed for the PCI patch >series, I don't see any reason not to enable it. You might extend the >commit message to remind those issues. Eric, Baptiste, Is vfio-platform no-iommu on your TODO list? I am happy to help test. If not, I can try work on this if you could guide me -:) Thanks, Peng. > >Best regards, >Baptiste > >> >> Best Regards >> >> Eric >> > >> > Alex >> > >> >>>> >> >>>> Signed-off-by: Peng Fan >> >>>> Cc: Baptiste Reynal >> >>>> Cc: Alex Williamson >> >>>> --- >> >>>> drivers/vfio/platform/vfio_platform_common.c | 6 +++--- >> >>>> 1 file changed, 3 insertions(+), 3 deletions(-) >> >>>> >> >>>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c >> >>>> index e65b142..582885e 100644 >> >>>> --- a/drivers/vfio/platform/vfio_platform_common.c >> >>>> +++ b/drivers/vfio/platform/vfio_platform_common.c >> >>>> @@ -561,7 +561,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, >> >>>> >> >>>> vdev->device = dev; >> >>>> >> >>>> - group = iommu_group_get(dev); >> >>>> + group = vfio_iommu_group_get(dev); >> >>>> if (!group) { >> >>>> pr_err("VFIO: No IOMMU group for device %s\n", vdev->name); >> >>>> return -EINVAL; >> >>>> @@ -569,7 +569,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, >> >>>> >> >>>> ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev); >> >>>> if (ret) { >> >>>> - iommu_group_put(group); >> >>>> + vfio_iommu_group_put(group); >> >>>> return ret; >> >>>> } >> >>>> >> >>>> @@ -589,7 +589,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) >> >>>> >> >>>> if (vdev) { >> >>>> vfio_platform_put_reset(vdev); >> >>>> - iommu_group_put(dev->iommu_group); >> >>>> + vfio_iommu_group_put(dev->iommu_group, dev); >> >>>> } >> >>>> >> >>>> return vdev; >> >>> >> > >>