[Qemu-devel] [PATCH v2 2/9] qmp: Add dirty-bitmap-add and dirty-bitmap-remove

[Fam Zheng]

The new command pair is added to manage user created dirty bitmap. The
dirty bitmap's name is mandatory and must be unique for the same device,
but different devices can have bitmaps with the same names.

Signed-off-by: Fam Zheng <address@hidden>
---
 blockdev.c       | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 qapi-schema.json | 45 ++++++++++++++++++++++++++++++++++++++++++
 qmp-commands.hx  | 49 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 154 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index c3422a1..662c950 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1713,6 +1713,66 @@ void qmp_block_set_io_throttle(const char *device, 
int64_t bps, int64_t bps_rd,
     }
 }
 
+void qmp_dirty_bitmap_add(const char *device, const char *name,
+                          bool has_granularity, int64_t granularity,
+                          Error **errp)
+{
+    BlockDriverState *bs;
+    BdrvDirtyBitmap *bitmap;
+
+    bs = bdrv_find(device);
+    if (!bs) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+        return;
+    }
+
+    if (!name || name[0] == '\0') {
+        error_setg(errp, "Bitmap name cannot be empty");
+        return;
+    }
+    if (has_granularity) {
+        if (granularity & (granularity - 1)) {
+            error_setg(errp, "Granularity must be power of 2");
+            return;
+        }
+    } else {
+        granularity = 65536;
+    }
+
+    bitmap = bdrv_create_dirty_bitmap(bs, granularity, name, errp);
+    if (!bitmap) {
+        return;
+    }
+}
+
+void qmp_dirty_bitmap_remove(const char *device, const char *name,
+                             Error **errp)
+{
+    BlockDriverState *bs;
+    BdrvDirtyBitmap *bitmap;
+
+    bs = bdrv_find(device);
+    if (!bs) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+        return;
+    }
+
+    if (!name || name[0] == '\0') {
+        error_setg(errp, "Bitmap name cannot be empty");
+        return;
+    }
+    bitmap = bdrv_find_dirty_bitmap(bs, name);
+    if (!bitmap) {
+        error_setg(errp, "Dirty bitmap not found: %s", name);
+        return;
+    }
+
+    /* Make it invisible to user in case the following
+     * bdrv_release_dirty_bitmap doens't free it because of refcnt */
+    bdrv_dirty_bitmap_make_anon(bs, bitmap);
+    bdrv_release_dirty_bitmap(bs, bitmap);
+}
+
 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
     const char *id = qdict_get_str(qdict, "id");
diff --git a/qapi-schema.json b/qapi-schema.json
index 4d5bc13..632bb10 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2180,6 +2180,51 @@
             '*on-target-error': 'BlockdevOnError' } }
 
 ##
+# @DirtyBitmap
+#
+# @device: name of device which the bitmap is tracking
+#
+# @name: name of the dirty bitmap
+#
+# @granularity: #optional the bitmap granularity, default is 64k for
+#               dirty-bitmap-add
+#
+# Since 2.1
+##
+{ 'type': 'DirtyBitmap',
+  'data': { 'device': 'str', 'name': 'str', '*granularity': 'int' } }
+
+##
+# @dirty-bitmap-add
+#
+# Create a dirty bitmap with a name on the device
+#
+# Returns: nothing on success
+#          If @device is not a valid block device, DeviceNotFound
+#          If @name is already taken, GenericError with an explaining message
+#
+# Since 2.1
+##
+{'command': 'dirty-bitmap-add',
+  'data': 'DirtyBitmap' }
+
+##
+# @dirty-bitmap-remove
+#
+# Remove a dirty bitmap on the device
+#
+# Setting granularity has no effect here.
+#
+# Returns: nothing on success
+#          If @device is not a valid block device, DeviceNotFound
+#          If @name is not found, GenericError with an explaining message
+#
+# Since 2.1
+##
+{'command': 'dirty-bitmap-remove',
+  'data': { 'device': 'str', 'name': 'str' } }
+
+##
 # @migrate_cancel
 #
 # Cancel the current executing migration process.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index d982cd6..c42516d 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1185,6 +1185,55 @@ Example:
 EQMP
 
     {
+        .name       = "dirty-bitmap-add",
+        .args_type  = "device:B,name:s,granularity:i?",
+        .mhandler.cmd_new = qmp_marshal_input_dirty_bitmap_add,
+    },
+    {
+        .name       = "dirty-bitmap-remove",
+        .args_type  = "device:B,name:s",
+        .mhandler.cmd_new = qmp_marshal_input_dirty_bitmap_remove,
+    },
+
+SQMP
+
+dirty-bitmap-add
+----------------
+
+Create a dirty bitmap with a name on the device, and start tracking the writes.
+
+Arguments:
+
+- "device": device name to create dirty bitmap (json-string)
+- "name": name of the new dirty bitmap (json-string)
+- "granularity": granularity to track writes with. (int)
+
+Example:
+
+-> { "execute": "dirty-bitmap-add", "arguments": { "device": "drive0",
+                                                   "name": "bitmap0" } }
+<- { "return": {} }
+
+dirty-bitmap-remove
+----------------
+
+Stop write tracking and remove the dirty bitmap that was created with
+dirty-bitmap-add.
+
+Arguments:
+
+- "device": device name to remove dirty bitmap (json-string)
+- "name": name of the dirty bitmap to remove (json-string)
+
+Example:
+
+-> { "execute": "dirty-bitmap-remove", "arguments": { "device": "drive0",
+                                                      "name": "bitmap0" } }
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "blockdev-snapshot-sync",
         .args_type  = 
"device:s?,node-name:s?,snapshot-file:s,snapshot-node-name:s?,format:s?,mode:s?",
         .mhandler.cmd_new = qmp_marshal_input_blockdev_snapshot_sync,
-- 
1.9.0