2 files changed, 28 insertions, 3 deletions

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 7623703943..f1070d6dc7 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -1,6 +1,7 @@
 #ifndef QDEV_CORE_H
 #define QDEV_CORE_H
 
+#include "qemu/atomic.h"
 #include "qemu/queue.h"
 #include "qemu/bitmap.h"
 #include "qemu/rcu.h"
@@ -168,9 +169,6 @@ typedef struct {
 
 /**
  * DeviceState:
- * @realized: Indicates whether the device has been fully constructed.
- *            When accessed outside big qemu lock, must be accessed with
- *            qatomic_load_acquire()
  * @reset: ResettableState for the device; handled by Resettable interface.
  *
  * This structure should not be accessed directly.  We declare it here
@@ -340,6 +338,19 @@ DeviceState *qdev_new(const char *name);
 DeviceState *qdev_try_new(const char *name);
 
 /**
+ * qdev_is_realized:
+ * @dev: The device to check.
+ *
+ * May be called outside big qemu lock.
+ *
+ * Returns: %true% if the device has been fully constructed, %false% otherwise.
+ */
+static inline bool qdev_is_realized(DeviceState *dev)
+{
+    return qatomic_load_acquire(&dev->realized);
+}
+
+/**
  * qdev_realize: Realize @dev.
  * @dev: device to realize
  * @bus: bus to plug it into (may be NULL)
diff --git a/include/hw/scsi/scsi.h b/include/hw/scsi/scsi.h
index 6f23a7a73e..e2bb1a2fbf 100644
--- a/include/hw/scsi/scsi.h
+++ b/include/hw/scsi/scsi.h
@@ -133,6 +133,16 @@ struct SCSIBusInfo {
     void (*save_request)(QEMUFile *f, SCSIRequest *req);
     void *(*load_request)(QEMUFile *f, SCSIRequest *req);
     void (*free_request)(SCSIBus *bus, void *priv);
+
+    /*
+     * Temporarily stop submitting new requests between drained_begin() and
+     * drained_end(). Called from the main loop thread with the BQL held.
+     *
+     * Implement these callbacks if request processing is triggered by a file
+     * descriptor like an EventNotifier. Otherwise set them to NULL.
+     */
+    void (*drained_begin)(SCSIBus *bus);
+    void (*drained_end)(SCSIBus *bus);
 };
 
 #define TYPE_SCSI_BUS "SCSI"
@@ -144,6 +154,8 @@ struct SCSIBus {
 
     SCSISense unit_attention;
     const SCSIBusInfo *info;
+
+    int drain_count; /* protected by BQL */
 };
 
 /**
@@ -213,6 +225,8 @@ void scsi_req_cancel_complete(SCSIRequest *req);
 void scsi_req_cancel(SCSIRequest *req);
 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier);
 void scsi_req_retry(SCSIRequest *req);
+void scsi_device_drained_begin(SCSIDevice *sdev);
+void scsi_device_drained_end(SCSIDevice *sdev);
 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense);
 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense);
 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense);