On Mon, 25 Jan 2021 17:04:01 +0800 Shenming Lu <[email protected]> wrote:
> If IOMMU_DEV_FEAT_IOPF is set for the VFIO device, which means that > the delivering of page faults of this device from the IOMMU is enabled, > we register the VFIO page fault handler to complete the whole faulting > path (HW+SW). And add a iopf_enabled field in struct vfio_device to > record it. > > Signed-off-by: Shenming Lu <[email protected]> > --- > drivers/vfio/vfio.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c > index ff7797260d0f..fd885d99ee0f 100644 > --- a/drivers/vfio/vfio.c > +++ b/drivers/vfio/vfio.c > @@ -97,6 +97,7 @@ struct vfio_device { > struct vfio_group *group; > struct list_head group_next; > void *device_data; > + bool iopf_enabled; > }; > > #ifdef CONFIG_VFIO_NOIOMMU > @@ -532,6 +533,21 @@ static struct vfio_group *vfio_group_get_from_dev(struct > device *dev) > /** > * Device objects - create, release, get, put, search > */ > + > +static void vfio_device_enable_iopf(struct vfio_device *device) > +{ > + struct device *dev = device->dev; > + > + if (!iommu_dev_has_feature(dev, IOMMU_DEV_FEAT_IOPF)) > + return; > + > + if (WARN_ON(iommu_register_device_fault_handler(dev, > + vfio_iommu_dev_fault_handler, dev))) The layering here is wrong, vfio-core doesn't manage the IOMMU, we have backend IOMMU drivers for that. We can't even assume we have IOMMU API support here, that's what the type1 backend handles. Thanks, Alex > + return; > + > + device->iopf_enabled = true; > +} > + > static > struct vfio_device *vfio_group_create_device(struct vfio_group *group, > struct device *dev, > @@ -549,6 +565,8 @@ struct vfio_device *vfio_group_create_device(struct > vfio_group *group, > device->group = group; > device->ops = ops; > device->device_data = device_data; > + /* By default try to enable IOPF */ > + vfio_device_enable_iopf(device); > dev_set_drvdata(dev, device); > > /* No need to get group_lock, caller has group reference */ > @@ -573,6 +591,8 @@ static void vfio_device_release(struct kref *kref) > mutex_unlock(&group->device_lock); > > dev_set_drvdata(device->dev, NULL); > + if (device->iopf_enabled) > + WARN_ON(iommu_unregister_device_fault_handler(device->dev)); > > kfree(device); >
