open_count is incremented before open_device() and decremented after
close_device() for each device in the set. This allows devices to
determine whether shared resources are in use without tracking them
manually or accessing the private open_count in vfio_device.
Signed-off-by: Anthony DeRossi <ajderossi@xxxxxxxxx>
---
drivers/vfio/vfio_main.c | 3 +++
include/linux/vfio.h | 1 +
2 files changed, 4 insertions(+)
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 9a4af880e941..6c65418fc7e3 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -761,6 +761,7 @@ static struct file *vfio_device_open(struct vfio_device *device)
mutex_lock(&device->group->group_lock);
device->kvm = device->group->kvm;
+ device->dev_set->open_count++;
if (device->ops->open_device) {
ret = device->ops->open_device(device);
if (ret)
@@ -809,6 +810,7 @@ static struct file *vfio_device_open(struct vfio_device *device)
}
err_undo_count:
mutex_unlock(&device->group->group_lock);
+ device->dev_set->open_count--;
device->open_count--;
if (device->open_count == 0 && device->kvm)
device->kvm = NULL;
@@ -1023,6 +1025,7 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep)
device->ops->close_device(device);
vfio_device_container_unregister(device);
+ device->dev_set->open_count--;
}
mutex_unlock(&device->group->group_lock);
device->open_count--;
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index e7cebeb875dd..5becdcdf4ba2 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -28,6 +28,7 @@ struct vfio_device_set {
struct mutex lock;
struct list_head device_list;
unsigned int device_count;
+ unsigned int open_count;
};
struct vfio_device {
--
2.37.4
