virtio: defer config changed notifications
Defer config changed notifications that arrive during
probe/scan/freeze/restore.
This will allow drivers to set DRIVER_OK earlier, without worrying about
racing with config change interrupts.
This change will also benefit old hypervisors (before 2009)
that send interrupts without checking DRIVER_OK: previously,
the callback could race with driver-specific initialization.
This will also help simplify drivers.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cosmetic changes)
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 8df7ba8..65261a7 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -79,6 +79,9 @@
* virtio_device - representation of a device using virtio
* @index: unique position on the virtio bus
* @failed: saved value for CONFIG_S_FAILED bit (for restore)
+ * @config_enabled: configuration change reporting enabled
+ * @config_change_pending: configuration change reported while disabled
+ * @config_lock: protects configuration change reporting
* @dev: underlying device.
* @id: the device type identification (used to match it with a driver).
* @config: the configuration ops for this device.
@@ -90,6 +93,9 @@
struct virtio_device {
int index;
bool failed;
+ bool config_enabled;
+ bool config_change_pending;
+ spinlock_t config_lock;
struct device dev;
struct virtio_device_id id;
const struct virtio_config_ops *config;