From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933339AbcETJ5P (ORCPT ); Fri, 20 May 2016 05:57:15 -0400 Received: from mail-pf0-f196.google.com ([209.85.192.196]:35500 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755241AbcETJ5I (ORCPT ); Fri, 20 May 2016 05:57:08 -0400 Date: Fri, 20 May 2016 17:56:59 +0800 From: Peng Fan To: Eric Auger Cc: Baptiste Reynal , Alex Williamson , "open list:VFIO DRIVER" , open list Subject: Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put Message-ID: <20160520095658.GD23014@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> <20160520083627.GA23014@linux-7smt.suse> <573ED745.1040900@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <573ED745.1040900@linaro.org> 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 Eric, On Fri, May 20, 2016 at 11:22:13AM +0200, Eric Auger wrote: >Hi Peng, >On 05/20/2016 10:36 AM, Peng Fan wrote: >> 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 -:) >No it is not at the moment. shouldn't it work already with this very >patch? I will be happy to bring support to you if needed. This patch was code inspection work. Since it did not break vfio-platform iommu, I sent it out. I have not played well with userspace test code/step or qemu (: Is it ok for me to test vfio-platform no-iommu using a platform device withou DMA capability, such as simple UART? If it's ok, I'll follow the test code[1] to write my test code and do some test. Regards, Peng. [1] https://github.com/virtualopensystems/vfio-host-test/tree/master/src_test > >Best Regards > >Eric >> >> 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; >>>>>>> >>>>> >>>> >