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-rw-r--r--drivers/vfio/vfio.c24
-rw-r--r--include/linux/vfio.h2
2 files changed, 24 insertions, 2 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 13e0f39d91e0..4cde85501444 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -710,6 +710,7 @@ void *vfio_del_group_dev(struct device *dev)
struct vfio_group *group = device->group;
void *device_data = device->device_data;
struct vfio_unbound_dev *unbound;
+ unsigned int i = 0;
/*
* The group exists so long as we have a device reference. Get
@@ -737,8 +738,27 @@ void *vfio_del_group_dev(struct device *dev)
vfio_device_put(device);
- /* TODO send a signal to encourage this to be released */
- wait_event(vfio.release_q, !vfio_dev_present(group, dev));
+ /*
+ * If the device is still present in the group after the above
+ * 'put', then it is in use and we need to request it from the
+ * bus driver. The driver may in turn need to request the
+ * device from the user. We send the request on an arbitrary
+ * interval with counter to allow the driver to take escalating
+ * measures to release the device if it has the ability to do so.
+ */
+ do {
+ device = vfio_group_get_device(group, dev);
+ if (!device)
+ break;
+
+ if (device->ops->request)
+ device->ops->request(device_data, i++);
+
+ vfio_device_put(device);
+
+ } while (wait_event_interruptible_timeout(vfio.release_q,
+ !vfio_dev_present(group, dev),
+ HZ * 10) <= 0);
vfio_group_put(group);
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index d3204115f15d..2d67b8998fd8 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -26,6 +26,7 @@
* @ioctl: Perform ioctl(2) on device file descriptor, supporting VFIO_DEVICE_*
* operations documented below
* @mmap: Perform mmap(2) on a region of the device file descriptor
+ * @request: Request for the bus driver to release the device
*/
struct vfio_device_ops {
char *name;
@@ -38,6 +39,7 @@ struct vfio_device_ops {
long (*ioctl)(void *device_data, unsigned int cmd,
unsigned long arg);
int (*mmap)(void *device_data, struct vm_area_struct *vma);
+ void (*request)(void *device_data, unsigned int count);
};
extern int vfio_add_group_dev(struct device *dev,