If all the bits in a dirty bitmap cluster are ones, the cluster shouldn't be written. Instead the corresponding L1 entry should be set to 1.
Check if all bits in a memory region are ones and set 1 to L1 entries corresponding clusters filled with ones. Signed-off-by: Alexander Ivanov <alexander.iva...@virtuozzo.com> --- block/parallels-ext.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/block/parallels-ext.c b/block/parallels-ext.c index 1ec23aa1e7..67fa3b73c2 100644 --- a/block/parallels-ext.c +++ b/block/parallels-ext.c @@ -383,7 +383,7 @@ static void GRAPH_RDLOCK parallels_save_bitmap(BlockDriverState *bs, offset = 0; while ((offset = bdrv_dirty_bitmap_next_dirty(bitmap, offset, bm_size)) >= 0) { idx = offset / bits_per_cluster; - int64_t cluster_off, end, write_size; + int64_t cluster_off, end, write_size, first_zero; offset = QEMU_ALIGN_DOWN(offset, bits_per_cluster); end = MIN(bm_size, offset + bits_per_cluster); @@ -398,6 +398,16 @@ static void GRAPH_RDLOCK parallels_save_bitmap(BlockDriverState *bs, l1_table[idx] = 0; + first_zero = bdrv_dirty_bitmap_next_zero(bitmap, offset, bm_size); + if (first_zero < 0) { + goto clean_allocated_clusters; + } + if (first_zero - offset >= s->cluster_size) { + l1_table[idx] = 1; + offset = end; + continue; + } + cluster_off = parallels_allocate_host_clusters(bs, &alloc_size); if (cluster_off <= 0) { error_report("Can't save dirty bitmap '%s': cluster allocation error", -- 2.40.1