When a CIO_GONE notification is received the device_lost flag is
set in the virtio_device. This flag should be tested by a backend
in order to be able to prevent triggering final I/O to a device that
is not reachable any more.
The notification is ignored in case remove or set_offline is already
running. The virtio_device pointer might point to freed memory in that
case.
Signed-off-by: Heinz Graalfs <graalfs@xxxxxxxxxxxxxxxxxx>
Acked-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
---
drivers/s390/kvm/virtio_ccw.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index b939a7f..a468b9c 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -27,6 +27,7 @@
#include <linux/module.h>
#include <linux/io.h>
#include <linux/kvm_para.h>
+#include <linux/notifier.h>
#include <asm/setup.h>
#include <asm/irq.h>
#include <asm/cio.h>
@@ -1085,8 +1086,26 @@ out_free:
static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
{
- /* TODO: Check whether we need special handling here. */
- return 0;
+ int rc;
+ struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
+
+ /*
+ * Make sure vcdev is set
+ * i.e. set_offline/remove callback not already running
+ */
+ if (!vcdev)
+ return NOTIFY_DONE;
+
+ switch (event) {
+ case CIO_GONE:
+ atomic_inc(&vcdev->vdev.device_lost);
+ rc = NOTIFY_DONE;
+ break;
+ default:
+ rc = NOTIFY_DONE;
+ break;
+ }
+ return rc;
}
static struct ccw_device_id virtio_ids[] = {
--
1.8.3.1
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