Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty...

[linux-imx.git] / drivers / vfio / vfio.c

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index c488da5db7c7f1b0bda8e3b7559971ebfba0c442..842f4507883e1b1d10c99d343e35e450abf56db0 100644 (file)
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -494,27 +494,6 @@ static int vfio_group_nb_add_dev(struct vfio_group *group, struct device *dev)
        return 0;
 }
 
-static int vfio_group_nb_del_dev(struct vfio_group *group, struct device *dev)
-{
-       struct vfio_device *device;
-
-       /*
-        * Expect to fall out here.  If a device was in use, it would
-        * have been bound to a vfio sub-driver, which would have blocked
-        * in .remove at vfio_del_group_dev.  Sanity check that we no
-        * longer track the device, so it's safe to remove.
-        */
-       device = vfio_group_get_device(group, dev);
-       if (likely(!device))
-               return 0;
-
-       WARN("Device %s removed from live group %d!\n", dev_name(dev),
-            iommu_group_id(group->iommu_group));
-
-       vfio_device_put(device);
-       return 0;
-}
-
 static int vfio_group_nb_verify(struct vfio_group *group, struct device *dev)
 {
        /* We don't care what happens when the group isn't in use */
@@ -531,13 +510,11 @@ static int vfio_iommu_group_notifier(struct notifier_block *nb,
        struct device *dev = data;
 
        /*
-        * Need to go through a group_lock lookup to get a reference or
-        * we risk racing a group being removed.  Leave a WARN_ON for
-        * debuging, but if the group no longer exists, a spurious notify
-        * is harmless.
+        * Need to go through a group_lock lookup to get a reference or we
+        * risk racing a group being removed.  Ignore spurious notifies.
         */
        group = vfio_group_try_get(group);
-       if (WARN_ON(!group))
+       if (!group)
                return NOTIFY_OK;
 
        switch (action) {
@@ -545,7 +522,13 @@ static int vfio_iommu_group_notifier(struct notifier_block *nb,
                vfio_group_nb_add_dev(group, dev);
                break;
        case IOMMU_GROUP_NOTIFY_DEL_DEVICE:
-               vfio_group_nb_del_dev(group, dev);
+               /*
+                * Nothing to do here.  If the device is in use, then the
+                * vfio sub-driver should block the remove callback until
+                * it is unused.  If the device is unused or attached to a
+                * stub driver, then it should be released and we don't
+                * care that it will be going away.
+                */
                break;
        case IOMMU_GROUP_NOTIFY_BIND_DRIVER:
                pr_debug("%s: Device %s, group %d binding to driver\n",