[PATCH V8 25/39] cpr: notifiers

[Steve Sistare]

Add an interface to register notifiers for cpr transitions.  It is used to
support vfio cpr in a subsequent patch.

Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
---
 include/migration/cpr.h | 13 +++++++++++++
 migration/cpr.c         | 25 +++++++++++++++++++++++++
 stubs/cpr.c             | 10 ++++++++++
 3 files changed, 48 insertions(+)

diff --git a/include/migration/cpr.h b/include/migration/cpr.h
index b75dec4..ab5f53e 100644
--- a/include/migration/cpr.h
+++ b/include/migration/cpr.h
@@ -9,6 +9,7 @@
 #define MIGRATION_CPR_H
 
 #include "qapi/qapi-types-cpr.h"
+#include "qemu/notify.h"
 
 void cpr_init(int modes);
 void cpr_set_mode(CprMode mode);
@@ -37,4 +38,16 @@ int cpr_add_blocker(Error **reasonp, Error **errp, CprMode 
mode, ...);
 int cpr_add_blocker_str(const char *reason, Error **errp, CprMode mode, ...);
 void cpr_del_blocker(Error **reasonp);
 
+typedef enum CprNotifyState {
+    CPR_NOTIFY_EXEC,
+    CPR_NOTIFY_SAVE_FAILED,
+    CPR_NOTIFY_LOAD_FAILED,
+    CPR_NOTIFY_NUM
+} CprNotifyState;
+
+void cpr_add_notifier(Notifier *notify,
+                      void (*cb)(Notifier *notifier, void *data),
+                      CprNotifyState state);
+void cpr_remove_notifier(Notifier *notify);
+
 #endif
diff --git a/migration/cpr.c b/migration/cpr.c
index 8b3fffd..9d6bca4 100644
--- a/migration/cpr.c
+++ b/migration/cpr.c
@@ -105,6 +105,28 @@ static bool cpr_is_blocked(Error **errp, CprMode mode)
     return false;
 }
 
+static NotifierList cpr_notifiers[CPR_NOTIFY_NUM];
+
+void cpr_add_notifier(Notifier *notify,
+                      void (*cb)(Notifier *notifier, void *data),
+                      CprNotifyState state)
+{
+    assert(state >= 0 && state < CPR_NOTIFY_NUM);
+    notify->notify = cb;
+    notifier_list_add(&cpr_notifiers[state], notify);
+}
+
+void cpr_remove_notifier(Notifier *notify)
+{
+    notifier_remove(notify);
+    notify->notify = NULL;
+}
+
+static void cpr_call_notifiers(CprNotifyState state)
+{
+    notifier_list_notify(&cpr_notifiers[state], 0);
+}
+
 void qmp_cpr_save(const char *filename, CprMode mode, Error **errp)
 {
     int ret;
@@ -142,6 +164,7 @@ void qmp_cpr_save(const char *filename, CprMode mode, Error 
**errp)
     qemu_fclose(f);
     if (ret < 0) {
         error_setg(errp, "Error %d while saving VM state", ret);
+        cpr_call_notifiers(CPR_NOTIFY_SAVE_FAILED);
         goto err;
     }
 
@@ -182,6 +205,7 @@ void qmp_cpr_exec(strList *args, Error **errp)
         return;
     }
 
+    cpr_call_notifiers(CPR_NOTIFY_EXEC);
     assert(qemu_system_exec_request(args, errp) == 0);
 }
 
@@ -218,6 +242,7 @@ void qmp_cpr_load(const char *filename, CprMode mode, Error 
**errp)
     qemu_fclose(f);
     if (ret < 0) {
         error_setg(errp, "Error %d while loading VM state", ret);
+        cpr_call_notifiers(CPR_NOTIFY_LOAD_FAILED);
         goto out;
     }
 
diff --git a/stubs/cpr.c b/stubs/cpr.c
index 06a9a1c..9262e78 100644
--- a/stubs/cpr.c
+++ b/stubs/cpr.c
@@ -21,3 +21,13 @@ int cpr_add_blocker_str(const char *reason, Error **errp, 
CprMode mode, ...)
 void cpr_del_blocker(Error **reasonp)
 {
 }
+
+void cpr_add_notifier(Notifier *notify,
+                      void (*cb)(Notifier *notifier, void *data),
+                      CprNotifyState state)
+{
+}
+
+void cpr_remove_notifier(Notifier *notify)
+{
+}
-- 
1.8.3.1