[Qemu-devel] [PATCH v5 4/6] BitmapLog: cancel mechanism for an already running dump bitmap process

[Sanidhya Kashyap <sanidhya.iiith@gmail.com>]

Signed-off-by: Sanidhya Kashyap <sanidhya.iiith@gmail.com>
---
 hmp-commands.hx  | 14 ++++++++++++++
 hmp.c            |  5 +++++
 hmp.h            |  1 +
 qapi-schema.json |  9 +++++++++
 qmp-commands.hx  | 20 ++++++++++++++++++++
 savevm.c         | 14 ++++++++++++++
 6 files changed, 63 insertions(+)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index dca65bc..dcdc465 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1806,6 +1806,20 @@ STEXI
 dumps the writable working set of a VM's memory to a file
 ETEXI
 
+	{
+	.name       = "ldbc|log_dirty_bitmap_cancel",
+	.args_type  = "",
+	.params     = "",
+	.help       = "cancel the current bitmap dump process",
+	.mhandler.cmd = hmp_log_dirty_bitmap_cancel,
+},
+
+STEXI
+@item ldbc or log_dirty_bitmap_cancel
+@findex log_dirty_bitmap_cancel
+Cancel the current bitmap dump process
+ETEXI
+
 STEXI
 @end table
 ETEXI
diff --git a/hmp.c b/hmp.c
index 0a8831b..e485788 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1336,6 +1336,11 @@ void hmp_log_dirty_bitmap(Monitor *mon, const QDict *qdict)
     }
 }
 
+void hmp_log_dirty_bitmap_cancel(Monitor *mon, const QDict *qdict)
+{
+    qmp_log_dirty_bitmap_cancel(NULL);
+}
+
 void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
 {
     Error *err = NULL;
diff --git a/hmp.h b/hmp.h
index 02e8ee4..fcfb10f 100644
--- a/hmp.h
+++ b/hmp.h
@@ -96,6 +96,7 @@ void hmp_object_add(Monitor *mon, const QDict *qdict);
 void hmp_object_del(Monitor *mon, const QDict *qdict);
 void hmp_info_memdev(Monitor *mon, const QDict *qdict);
 void hmp_log_dirty_bitmap(Monitor *mon, const QDict *qdict);
+void hmp_log_dirty_bitmap_cancel(Monitor *mon, const QDict *qdict);
 void object_add_completion(ReadLineState *rs, int nb_args, const char *str);
 void object_del_completion(ReadLineState *rs, int nb_args, const char *str);
 void device_add_completion(ReadLineState *rs, int nb_args, const char *str);
diff --git a/qapi-schema.json b/qapi-schema.json
index 6aac367..b54c0ec 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3543,3 +3543,12 @@
 # Since 2.2
 ##
 { 'command': 'query-log-dirty-bitmap', 'returns': 'BitmapLogStateInfo' }
+
+##
+# @log-dirty-bitmap-cancel
+#
+# cancel the dirty bitmap logging process
+#
+# Since 2.2
+##
+{ 'command': 'log-dirty-bitmap-cancel' }
diff --git a/qmp-commands.hx b/qmp-commands.hx
index e79ed6a..d2e5192 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3814,3 +3814,23 @@ Example:
             "iterations": 10
             "period": 100 } }
 EQMP
+
+	{
+        .name       = "log-dirty-bitmap-cancel",
+        .args_type  = "",
+        .mhandler.cmd_new = qmp_marshal_input_log_dirty_bitmap_cancel,
+    },
+
+SQMP
+log-dirty-bitmap-cancel
+-----------------------
+
+Cancel the current bitmap dump process.
+
+Arguments: None.
+
+Example:
+
+-> { "execute": "log-dirty-bitmap-cancel" }
+<- { "return": {} }
+EQMP
diff --git a/savevm.c b/savevm.c
index 22e84fe..cbd4fc6 100644
--- a/savevm.c
+++ b/savevm.c
@@ -1532,6 +1532,20 @@ BitmapLogStateInfo *qmp_query_log_dirty_bitmap(Error **errp)
     return info;
 }
 
+void qmp_log_dirty_bitmap_cancel(Error **errp)
+{
+    BitmapLogState *b = log_bitmap_get_current_state();
+    int old_state;
+    do {
+        old_state = b->state;
+        if (old_state != LOG_BITMAP_STATE_ACTIVE) {
+            break;
+        }
+        log_bitmap_set_status(b, old_state,
+                                 LOG_BITMAP_STATE_CANCELING);
+    } while (b->state != LOG_BITMAP_STATE_CANCELING);
+}
+
 void qmp_xen_save_devices_state(const char *filename, Error **errp)
 {
     QEMUFile *f;
-- 
1.9.3