Hi Alex, > From: Alex Williamson [mailto:alex.williamson@xxxxxxxxxx] > Sent: Thursday, September 26, 2019 10:37 AM > To: Liu, Yi L <yi.l.liu@xxxxxxxxx> > Subject: Re: [PATCH v2 12/13] vfio/type1: use iommu_attach_group() for wrapping > PF/VF as mdev > > On Thu, 5 Sep 2019 15:59:29 +0800 > Liu Yi L <yi.l.liu@xxxxxxxxx> wrote: > > > This patch uses iommu_attach_group() to do group attach when it is for > > the case of wrapping a PF/VF as a mdev. iommu_attach_device() doesn't > > support non-singleton iommu group attach. With this change, wrapping > > PF/VF as mdev can work on non-singleton iommu groups. > > > > Cc: Kevin Tian <kevin.tian@xxxxxxxxx> > > Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> > > Suggested-by: Alex Williamson <alex.williamson@xxxxxxxxxx> > > Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx> > > --- > > drivers/vfio/vfio_iommu_type1.c | 22 ++++++++++++++++++---- > > 1 file changed, 18 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/vfio/vfio_iommu_type1.c > > b/drivers/vfio/vfio_iommu_type1.c index 054391f..317430d 100644 > > --- a/drivers/vfio/vfio_iommu_type1.c > > +++ b/drivers/vfio/vfio_iommu_type1.c > > @@ -1312,13 +1312,20 @@ static int vfio_mdev_attach_domain(struct > > device *dev, void *data) { > > struct iommu_domain *domain = data; > > struct device *iommu_device; > > + struct iommu_group *group; > > > > iommu_device = vfio_mdev_get_iommu_device(dev); > > if (iommu_device) { > > if (iommu_dev_feature_enabled(iommu_device, > IOMMU_DEV_FEAT_AUX)) > > return iommu_aux_attach_device(domain, iommu_device); > > - else > > - return iommu_attach_device(domain, iommu_device); > > + else { > > + group = iommu_group_get(iommu_device); > > + if (!group) { > > + WARN_ON(1); > > What's the value of the WARN_ON here and below? Let me remove it. > iommu_group_get() increments the kobject reference, looks like it's leaked. Thanks, Oops, yes, should use dev->iommu_group. Let me fix it. > > Alex Thanks, Yi Liu
