Meta bitmap is a 'dirty bitmap' for the BdrvDirtyBitmap. It tracks
changes (set/unset) of this BdrvDirtyBitmap. It is needed for live
migration of block dirty bitmaps.
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
block.c | 40 ++++++++++++++++++++++++++++++++++++++++
include/block/block.h | 5 +++++
2 files changed, 45 insertions(+)
diff --git a/block.c b/block.c
index a127fd2..aaa08b8 100644
--- a/block.c
+++ b/block.c
@@ -58,9 +58,15 @@
* (3) successor is set: frozen mode.
* A frozen bitmap cannot be renamed, deleted, anonymized, cleared, set,
* or enabled. A frozen bitmap can only abdicate() or reclaim().
+ *
+ * Meta bitmap:
+ * Meta bitmap is a 'dirty bitmap' for the BdrvDirtyBitmap. It tracks changes
+ * (set/unset) of this BdrvDirtyBitmap. It is needed for live migration of
+ * block dirty bitmaps.
*/
struct BdrvDirtyBitmap {
HBitmap *bitmap; /* Dirty sector bitmap implementation */
+ HBitmap *meta_bitmap; /* Meta bitmap */
BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */
char *name; /* Optional non-empty unique ID */
int64_t size; /* Size of the bitmap (Number of sectors) */
@@ -5398,6 +5404,31 @@ void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap)
bitmap->name = NULL;
}
+HBitmap *bdrv_create_meta_bitmap(BdrvDirtyBitmap *bitmap,
+ uint64_t granularity)
+{
+ uint64_t sector_granularity;
+
+ assert((granularity & (granularity - 1)) == 0);
+
+ granularity *= 8 * bdrv_dirty_bitmap_granularity(bitmap);
+ sector_granularity = granularity >> BDRV_SECTOR_BITS;
+ assert(sector_granularity);
+
+ bitmap->meta_bitmap =
+ hbitmap_alloc(bitmap->size, ffsll(sector_granularity) - 1);
+
+ return bitmap->meta_bitmap;
+}
+
+void bdrv_release_meta_bitmap(BdrvDirtyBitmap *bitmap)
+{
+ if (bitmap->meta_bitmap) {
+ hbitmap_free(bitmap->meta_bitmap);
+ bitmap->meta_bitmap = NULL;
+ }
+}
+
BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
uint32_t granularity,
const char *name,
@@ -5532,6 +5563,9 @@ void bdrv_release_dirty_bitmap(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap)
assert(!bdrv_dirty_bitmap_frozen(bm));
QLIST_REMOVE(bitmap, list);
hbitmap_free(bitmap->bitmap);
+ if (bitmap->meta_bitmap) {
+ hbitmap_free(bitmap->meta_bitmap);
+ }
g_free(bitmap->name);
g_free(bitmap);
return;
@@ -5659,6 +5693,9 @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
{
assert(bdrv_dirty_bitmap_enabled(bitmap));
hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
+ if (bitmap->meta_bitmap) {
+ hbitmap_set(bitmap->meta_bitmap, cur_sector, nr_sectors);
+ }
}
void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
@@ -5666,6 +5703,9 @@ void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
{
assert(bdrv_dirty_bitmap_enabled(bitmap));
hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
+ if (bitmap->meta_bitmap) {
+ hbitmap_set(bitmap->meta_bitmap, cur_sector, nr_sectors);
+ }
}
void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap)
diff --git a/include/block/block.h b/include/block/block.h
index c6a928d..f2c62f6 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -4,6 +4,7 @@
#include "block/aio.h"
#include "qemu-common.h"
#include "qemu/option.h"
+#include "qemu/hbitmap.h"
#include "block/coroutine.h"
#include "block/accounting.h"
#include "qapi/qmp/qobject.h"
@@ -487,6 +488,10 @@ void bdrv_dirty_bitmap_deserialize_zeroes(BdrvDirtyBitmap
*bitmap,
uint64_t start, uint64_t count);
void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap);
+HBitmap *bdrv_create_meta_bitmap(BdrvDirtyBitmap *bitmap,
+ uint64_t granularity);
+void bdrv_release_meta_bitmap(BdrvDirtyBitmap *bitmap);
+
void bdrv_enable_copy_on_read(BlockDriverState *bs);
void bdrv_disable_copy_on_read(BlockDriverState *bs);