[Qemu-devel] [PATCH RFC v2 4/8] block: add dirty-dirty bitmaps

[Vladimir Sementsov-Ogievskiy <vsementsov@parallels.com>]

A dirty-dirty bitmap is a dirty bitmap for BdrvDirtyBitmap. It tracks
set/unset changes of BdrvDirtyBitmap.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@parallels.com>
---
 block.c               | 44 ++++++++++++++++++++++++++++++++++++++++++++
 include/block/block.h |  5 +++++
 2 files changed, 49 insertions(+)

diff --git a/block.c b/block.c
index 9860fc1..8ab724b 100644
--- a/block.c
+++ b/block.c
@@ -53,6 +53,7 @@
 
 struct BdrvDirtyBitmap {
     HBitmap *bitmap;
+    HBitmap *dirty_dirty_bitmap;
     BdrvDirtyBitmap *originator;
     int64_t size;
     int64_t granularity;
@@ -5373,6 +5374,30 @@ BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
     return originator;
 }
 
+HBitmap *bdrv_create_dirty_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+                                        uint64_t granularity)
+{
+    uint64_t sector_granularity;
+
+    assert((granularity & (granularity - 1)) == 0);
+
+    granularity *= 8 * bitmap->granularity;
+    sector_granularity = granularity >> BDRV_SECTOR_BITS;
+    assert(sector_granularity);
+
+    bitmap->dirty_dirty_bitmap =
+        hbitmap_alloc(bitmap->size, ffsll(sector_granularity) - 1);
+
+    return bitmap->dirty_dirty_bitmap;
+}
+
+void bdrv_release_dirty_dirty_bitmap(BdrvDirtyBitmap *bitmap)
+{
+    if (bitmap->dirty_dirty_bitmap) {
+        hbitmap_free(bitmap->dirty_dirty_bitmap);
+        bitmap->dirty_dirty_bitmap = NULL;
+    }
+}
 
 void bdrv_print_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 {
@@ -5447,6 +5472,9 @@ void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
         if (bm == bitmap) {
             QLIST_REMOVE(bitmap, list);
             hbitmap_free(bitmap->bitmap);
+            if (bitmap->dirty_dirty_bitmap) {
+                hbitmap_free(bitmap->dirty_dirty_bitmap);
+            }
             g_free(bitmap->name);
             g_free(bitmap);
             return;
@@ -5534,6 +5562,10 @@ void bdrv_set_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
 {
     if (bitmap->enabled) {
         hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
+
+        if (bitmap->dirty_dirty_bitmap) {
+            hbitmap_set(bitmap->dirty_dirty_bitmap, cur_sector, nr_sectors);
+        }
     }
 }
 
@@ -5541,6 +5573,9 @@ void bdrv_reset_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
                              int64_t cur_sector, int nr_sectors)
 {
     hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
+    if (bitmap->dirty_dirty_bitmap) {
+        hbitmap_set(bitmap->dirty_dirty_bitmap, cur_sector, nr_sectors);
+    }
 }
 
 /**
@@ -5550,6 +5585,9 @@ void bdrv_reset_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
 void bdrv_clear_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
 {
     hbitmap_reset(bitmap->bitmap, 0, bitmap->size);
+    if (bitmap->dirty_dirty_bitmap) {
+        hbitmap_set(bitmap->dirty_dirty_bitmap, 0, bitmap->size);
+    }
 }
 
 const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap)
@@ -5597,6 +5635,9 @@ static void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
             continue;
         }
         hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
+        if (bitmap->dirty_dirty_bitmap) {
+            hbitmap_set(bitmap->dirty_dirty_bitmap, cur_sector, nr_sectors);
+        }
     }
 }
 
@@ -5606,6 +5647,9 @@ static void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
     BdrvDirtyBitmap *bitmap;
     QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
         hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
+        if (bitmap->dirty_dirty_bitmap) {
+            hbitmap_set(bitmap->dirty_dirty_bitmap, cur_sector, nr_sectors);
+        }
     }
 }
 
diff --git a/include/block/block.h b/include/block/block.h
index 0890cd2..648b0a9 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"
@@ -473,6 +474,10 @@ void bdrv_dirty_bitmap_deserialize_part0(BdrvDirtyBitmap *bitmap,
                                          uint64_t start, uint64_t count);
 void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap);
 
+HBitmap *bdrv_create_dirty_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+                                        uint64_t granularity);
+void bdrv_release_dirty_dirty_bitmap(BdrvDirtyBitmap *bitmap);
+
 void bdrv_enable_copy_on_read(BlockDriverState *bs);
 void bdrv_disable_copy_on_read(BlockDriverState *bs);
 
-- 
1.9.1