From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932681AbcETIAF (ORCPT ); Fri, 20 May 2016 04:00:05 -0400 Received: from mail-wm0-f50.google.com ([74.125.82.50]:36092 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754742AbcETIAD (ORCPT ); Fri, 20 May 2016 04:00:03 -0400 Subject: Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put To: Alex Williamson , Peng Fan References: <1462788103-19906-1-git-send-email-van.freenix@gmail.com> <20160509093238.3901f0b7@t450s.home> <20160510074025.GA1064@linux-7smt.suse> <20160519150149.7a8b80ba@ul30vt.home> Cc: b.reynal@virtualopensystems.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org From: Eric Auger Message-ID: <573EC3A8.4050008@linaro.org> Date: Fri, 20 May 2016 09:58:32 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <20160519150149.7a8b80ba@ul30vt.home> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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; >>> >