Merge remote-tracking branch 'remotes/ericb/tags/pull-bitmaps-2020-05-26-v3' into staging

bitmaps patches for 2020-05-26

- fix non-blockdev migration of bitmaps when mirror job is in use
- add bitmap sizing to 'qemu-img measure'
- add 'qemu-img convert --bitmaps'

# gpg: Signature made Thu 28 May 2020 19:16:47 BST
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-bitmaps-2020-05-26-v3:
  iotests: Add test 291 to for qemu-img bitmap coverage
  qemu-img: Add convert --bitmaps option
  qemu-img: Factor out code for merging bitmaps
  qcow2: Expose bitmaps' size during measure
  iotests: Fix test 178
  migration: forbid bitmap migration by generated node-name
  migration: add_bitmaps_to_list: check disk name once
  iotests: 194: test also migration of dirty bitmap
  migration: fix bitmaps pre-blockdev migration with mirror job
  block/dirty-bitmap: add bdrv_has_named_bitmaps helper
  migration: refactor init_dirty_bitmap_migration

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

21 files changed, 576 insertions, 71 deletions

diff --git a/block/crypto.c b/block/crypto.c
index b216e12..973b57b 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -552,7 +552,7 @@ static BlockMeasureInfo *block_crypto_measure(QemuOpts *opts,
      * Unallocated blocks are still encrypted so allocation status makes no
      * difference to the file size.
      */
-    info = g_new(BlockMeasureInfo, 1);
+    info = g_new0(BlockMeasureInfo, 1);
     info->fully_allocated = luks_payload_size + size;
     info->required = luks_payload_size + size;
     return info;
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index f9bfc77..c01319b 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -818,6 +818,19 @@ bool bdrv_has_readonly_bitmaps(BlockDriverState *bs)
     return false;
 }
 
+bool bdrv_has_named_bitmaps(BlockDriverState *bs)
+{
+    BdrvDirtyBitmap *bm;
+
+    QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
+        if (bdrv_dirty_bitmap_name(bm)) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
 /* Called with BQL taken. */
 void bdrv_dirty_bitmap_set_persistence(BdrvDirtyBitmap *bitmap, bool persistent)
 {
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 1cf6d2a..7bf1250 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1755,3 +1755,39 @@ bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs)
 
     return s->qcow_version >= 3;
 }
+
+/*
+ * Compute the space required for bitmaps in @bs.
+ *
+ * The computation is based as if copying to a new image with the
+ * given @cluster_size, which may differ from the cluster size in @bs.
+ */
+uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
+                                                uint32_t cluster_size)
+{
+    uint64_t bitmaps_size = 0;
+    BdrvDirtyBitmap *bm;
+    size_t bitmap_dir_size = 0;
+
+    FOR_EACH_DIRTY_BITMAP(bs, bm) {
+        if (bdrv_dirty_bitmap_get_persistence(bm)) {
+            const char *name = bdrv_dirty_bitmap_name(bm);
+            uint32_t granularity = bdrv_dirty_bitmap_granularity(bm);
+            uint64_t bmbytes =
+                get_bitmap_bytes_needed(bdrv_dirty_bitmap_size(bm),
+                                        granularity);
+            uint64_t bmclusters = DIV_ROUND_UP(bmbytes, cluster_size);
+
+            /* Assume the entire bitmap is allocated */
+            bitmaps_size += bmclusters * cluster_size;
+            /* Also reserve space for the bitmap table entries */
+            bitmaps_size += ROUND_UP(bmclusters * sizeof(uint64_t),
+                                     cluster_size);
+            /* And space for contribution to bitmap directory size */
+            bitmap_dir_size += calc_dir_entry_size(strlen(name), 0);
+        }
+    }
+    bitmaps_size += ROUND_UP(bitmap_dir_size, cluster_size);
+
+    return bitmaps_size;
+}
diff --git a/block/qcow2.c b/block/qcow2.c
index dfab8d2..0cd2e67 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -4953,16 +4953,24 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
         required = virtual_size;
     }
 
-    info = g_new(BlockMeasureInfo, 1);
+    info = g_new0(BlockMeasureInfo, 1);
     info->fully_allocated =
         qcow2_calc_prealloc_size(virtual_size, cluster_size,
                                  ctz32(refcount_bits)) + luks_payload_size;
 
-    /* Remove data clusters that are not required.  This overestimates the
+    /*
+     * Remove data clusters that are not required.  This overestimates the
      * required size because metadata needed for the fully allocated file is
-     * still counted.
+     * still counted.  Show bitmaps only if both source and destination
+     * would support them.
      */
     info->required = info->fully_allocated - virtual_size + required;
+    info->has_bitmaps = version >= 3 && in_bs &&
+        bdrv_supports_persistent_dirty_bitmap(in_bs);
+    if (info->has_bitmaps) {
+        info->bitmaps = qcow2_get_persistent_dirty_bitmap_size(in_bs,
+                                                               cluster_size);
+    }
     return info;
 
 err:
diff --git a/block/qcow2.h b/block/qcow2.h
index 402e8ac..7ce2c23 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -783,6 +783,8 @@ int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
                                             const char *name,
                                             Error **errp);
 bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs);
+uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
+                                                uint32_t cluster_size);
 
 ssize_t coroutine_fn
 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
diff --git a/block/raw-format.c b/block/raw-format.c
index 018441b..233d019 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -359,7 +359,7 @@ static BlockMeasureInfo *raw_measure(QemuOpts *opts, BlockDriverState *in_bs,
                             BDRV_SECTOR_SIZE);
     }
 
-    info = g_new(BlockMeasureInfo, 1);
+    info = g_new0(BlockMeasureInfo, 1);
     info->required = required;
 
     /* Unallocated sectors count towards the file size in raw images */
diff --git a/docs/tools/qemu-img.rst b/docs/tools/qemu-img.rst
index 38d464e..69cd9a3 100644
--- a/docs/tools/qemu-img.rst
+++ b/docs/tools/qemu-img.rst
@@ -162,6 +162,10 @@ Parameters to convert subcommand:
 
 .. program:: qemu-img-convert
 
+.. option:: --bitmaps
+
+  Additionally copy all persistent bitmaps from the top layer of the source
+
 .. option:: -n
 
   Skip the creation of the target volume
@@ -397,7 +401,7 @@ Command description:
   4
     Error on reading data
 
-.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [--target-is-zero] [-U] [-C] [-c] [-p] [-q] [-n] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-O OUTPUT_FMT] [-B BACKING_FILE] [-o OPTIONS] [-l SNAPSHOT_PARAM] [-S SPARSE_SIZE] [-m NUM_COROUTINES] [-W] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
+.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [--target-is-zero] [--bitmaps] [-U] [-C] [-c] [-p] [-q] [-n] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-O OUTPUT_FMT] [-B BACKING_FILE] [-o OPTIONS] [-l SNAPSHOT_PARAM] [-S SPARSE_SIZE] [-m NUM_COROUTINES] [-W] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
 
   Convert the disk image *FILENAME* or a snapshot *SNAPSHOT_PARAM*
   to disk image *OUTPUT_FILENAME* using format *OUTPUT_FMT*. It can
@@ -616,6 +620,7 @@ Command description:
 
     required size: 524288
     fully allocated size: 1074069504
+    bitmaps size: 0
 
   The ``required size`` is the file size of the new image.  It may be smaller
   than the virtual disk size if the image format supports compact representation.
@@ -625,6 +630,12 @@ Command description:
   occupy with the exception of internal snapshots, dirty bitmaps, vmstate data,
   and other advanced image format features.
 
+  The ``bitmaps size`` is the additional size required in order to
+  copy bitmaps from a source image in addition to the guest-visible
+  data; the line is omitted if either source or destination lacks
+  bitmap support, or 0 if bitmaps are supported but there is nothing
+  to copy.
+
 .. option:: snapshot [--object OBJECTDEF] [--image-opts] [-U] [-q] [-l | -a SNAPSHOT | -c SNAPSHOT | -d SNAPSHOT] FILENAME
 
   List, apply, create or delete snapshots in image *FILENAME*.
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 5a8d52e..36e8da4 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -95,6 +95,7 @@ int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap);
 void bdrv_dirty_bitmap_truncate(BlockDriverState *bs, int64_t bytes);
 bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap);
 bool bdrv_has_readonly_bitmaps(BlockDriverState *bs);
+bool bdrv_has_named_bitmaps(BlockDriverState *bs);
 bool bdrv_dirty_bitmap_get_autoload(const BdrvDirtyBitmap *bitmap);
 bool bdrv_dirty_bitmap_get_persistence(BdrvDirtyBitmap *bitmap);
 bool bdrv_dirty_bitmap_inconsistent(const BdrvDirtyBitmap *bitmap);
diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
index 7eaffac..47bc0f6 100644
--- a/migration/block-dirty-bitmap.c
+++ b/migration/block-dirty-bitmap.c
@@ -268,57 +268,118 @@ static void dirty_bitmap_mig_cleanup(void)
 }
 
 /* Called with iothread lock taken. */
-static int init_dirty_bitmap_migration(void)
+static int add_bitmaps_to_list(BlockDriverState *bs, const char *bs_name)
 {
-    BlockDriverState *bs;
     BdrvDirtyBitmap *bitmap;
     DirtyBitmapMigBitmapState *dbms;
     Error *local_err = NULL;
 
+    bitmap = bdrv_dirty_bitmap_first(bs);
+    if (!bitmap) {
+        return 0;
+    }
+
+    if (!bs_name || strcmp(bs_name, "") == 0) {
+        error_report("Bitmap '%s' in unnamed node can't be migrated",
+                     bdrv_dirty_bitmap_name(bitmap));
+        return -1;
+    }
+
+    if (bs_name[0] == '#') {
+        error_report("Bitmap '%s' in a node with auto-generated "
+                     "name '%s' can't be migrated",
+                     bdrv_dirty_bitmap_name(bitmap), bs_name);
+        return -1;
+    }
+
+    FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
+        if (!bdrv_dirty_bitmap_name(bitmap)) {
+            continue;
+        }
+
+        if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, &local_err)) {
+            error_report_err(local_err);
+            return -1;
+        }
+
+        bdrv_ref(bs);
+        bdrv_dirty_bitmap_set_busy(bitmap, true);
+
+        dbms = g_new0(DirtyBitmapMigBitmapState, 1);
+        dbms->bs = bs;
+        dbms->node_name = bs_name;
+        dbms->bitmap = bitmap;
+        dbms->total_sectors = bdrv_nb_sectors(bs);
+        dbms->sectors_per_chunk = CHUNK_SIZE * 8 *
+            bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
+        if (bdrv_dirty_bitmap_enabled(bitmap)) {
+            dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_ENABLED;
+        }
+        if (bdrv_dirty_bitmap_get_persistence(bitmap)) {
+            dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT;
+        }
+
+        QSIMPLEQ_INSERT_TAIL(&dirty_bitmap_mig_state.dbms_list,
+                             dbms, entry);
+    }
+
+    return 0;
+}
+
+/* Called with iothread lock taken. */
+static int init_dirty_bitmap_migration(void)
+{
+    BlockDriverState *bs;
+    DirtyBitmapMigBitmapState *dbms;
+    GHashTable *handled_by_blk = g_hash_table_new(NULL, NULL);
+    BlockBackend *blk;
+
     dirty_bitmap_mig_state.bulk_completed = false;
     dirty_bitmap_mig_state.prev_bs = NULL;
     dirty_bitmap_mig_state.prev_bitmap = NULL;
     dirty_bitmap_mig_state.no_bitmaps = false;
 
-    for (bs = bdrv_next_all_states(NULL); bs; bs = bdrv_next_all_states(bs)) {
-        const char *name = bdrv_get_device_or_node_name(bs);
+    /*
+     * Use blockdevice name for direct (or filtered) children of named block
+     * backends.
+     */
+    for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
+        const char *name = blk_name(blk);
 
-        FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
-            if (!bdrv_dirty_bitmap_name(bitmap)) {
-                continue;
-            }
+        if (!name || strcmp(name, "") == 0) {
+            continue;
+        }
 
-            if (!name || strcmp(name, "") == 0) {
-                error_report("Found bitmap '%s' in unnamed node %p. It can't "
-                             "be migrated", bdrv_dirty_bitmap_name(bitmap), bs);
-                goto fail;
+        bs = blk_bs(blk);
+
+        /* Skip filters without bitmaps */
+        while (bs && bs->drv && bs->drv->is_filter &&
+               !bdrv_has_named_bitmaps(bs))
+        {
+            if (bs->backing) {
+                bs = bs->backing->bs;
+            } else if (bs->file) {
+                bs = bs->file->bs;
+            } else {
+                bs = NULL;
             }
+        }
 
-            if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT,
-                                        &local_err)) {
-                error_report_err(local_err);
+        if (bs && bs->drv && !bs->drv->is_filter) {
+            if (add_bitmaps_to_list(bs, name)) {
                 goto fail;
             }
+            g_hash_table_add(handled_by_blk, bs);
+        }
+    }
 
-            bdrv_ref(bs);
-            bdrv_dirty_bitmap_set_busy(bitmap, true);
-
-            dbms = g_new0(DirtyBitmapMigBitmapState, 1);
-            dbms->bs = bs;
-            dbms->node_name = name;
-            dbms->bitmap = bitmap;
-            dbms->total_sectors = bdrv_nb_sectors(bs);
-            dbms->sectors_per_chunk = CHUNK_SIZE * 8 *
-                bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
-            if (bdrv_dirty_bitmap_enabled(bitmap)) {
-                dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_ENABLED;
-            }
-            if (bdrv_dirty_bitmap_get_persistence(bitmap)) {
-                dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT;
-            }
+    for (bs = bdrv_next_all_states(NULL); bs; bs = bdrv_next_all_states(bs)) {
+        if (g_hash_table_contains(handled_by_blk, bs)) {
+            continue;
+        }
 
-            QSIMPLEQ_INSERT_TAIL(&dirty_bitmap_mig_state.dbms_list,
-                                 dbms, entry);
+        if (add_bitmaps_to_list(bs, bdrv_get_node_name(bs))) {
+            goto fail;
         }
     }
 
@@ -331,9 +392,12 @@ static int init_dirty_bitmap_migration(void)
         dirty_bitmap_mig_state.no_bitmaps = true;
     }
 
+    g_hash_table_destroy(handled_by_blk);
+
     return 0;
 
 fail:
+    g_hash_table_destroy(handled_by_blk);
     dirty_bitmap_mig_cleanup();
 
     return -1;
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 6fbacdd..0e1c6a5 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -636,18 +636,24 @@
 # efficiently so file size may be smaller than virtual disk size.
 #
 # The values are upper bounds that are guaranteed to fit the new image file.
-# Subsequent modification, such as internal snapshot or bitmap creation, may
-# require additional space and is not covered here.
+# Subsequent modification, such as internal snapshot or further bitmap
+# creation, may require additional space and is not covered here.
 #
-# @required: Size required for a new image file, in bytes.
+# @required: Size required for a new image file, in bytes, when copying just
+#            allocated guest-visible contents.
 #
 # @fully-allocated: Image file size, in bytes, once data has been written
-#                   to all sectors.
+#                   to all sectors, when copying just guest-visible contents.
+#
+# @bitmaps: Additional size required if all the top-level bitmap metadata
+#           in the source image were to be copied to the destination,
+#           present only when source and destination both support
+#           persistent bitmaps. (since 5.1)
 #
 # Since: 2.10
 ##
 { 'struct': 'BlockMeasureInfo',
-  'data': {'required': 'int', 'fully-allocated': 'int'} }
+  'data': {'required': 'int', 'fully-allocated': 'int', '*bitmaps': 'int'} }
 
 ##
 # @query-block:
diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index a87d3cb..10b910b 100644
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -46,9 +46,9 @@ SRST
 ERST
 
 DEF("convert", img_convert,
-    "convert [--object objectdef] [--image-opts] [--target-image-opts] [--target-is-zero] [-U] [-C] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-B backing_file] [-o options] [-l snapshot_param] [-S sparse_size] [-m num_coroutines] [-W] [--salvage] filename [filename2 [...]] output_filename")
+    "convert [--object objectdef] [--image-opts] [--target-image-opts] [--target-is-zero] [--bitmaps] [-U] [-C] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-B backing_file] [-o options] [-l snapshot_param] [-S sparse_size] [-m num_coroutines] [-W] [--salvage] filename [filename2 [...]] output_filename")
 SRST
-.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [--target-is-zero] [-U] [-C] [-c] [-p] [-q] [-n] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-O OUTPUT_FMT] [-B BACKING_FILE] [-o OPTIONS] [-l SNAPSHOT_PARAM] [-S SPARSE_SIZE] [-m NUM_COROUTINES] [-W] [--salvage] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
+.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [--target-is-zero] [--bitmaps] [-U] [-C] [-c] [-p] [-q] [-n] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-O OUTPUT_FMT] [-B BACKING_FILE] [-o OPTIONS] [-l SNAPSHOT_PARAM] [-S SPARSE_SIZE] [-m NUM_COROUTINES] [-W] [--salvage] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
 ERST
 
 DEF("create", img_create,
diff --git a/qemu-img.c b/qemu-img.c
index 2d30682..d7e846e 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -78,6 +78,7 @@ enum {
     OPTION_ENABLE = 272,
     OPTION_DISABLE = 273,
     OPTION_MERGE = 274,
+    OPTION_BITMAPS = 275,
 };
 
 typedef enum OutputFormat {
@@ -191,6 +192,7 @@ static void QEMU_NORETURN help(void)
            "       hiding corruption that has already occurred.\n"
            "\n"
            "Parameters to convert subcommand:\n"
+           "  '--bitmaps' copies all top-level persistent bitmaps to destination\n"
            "  '-m' specifies how many coroutines work in parallel during the convert\n"
            "       process (defaults to 8)\n"
            "  '-W' allow to write to the target out of order rather than sequential\n"
@@ -1638,6 +1640,24 @@ out4:
     return ret;
 }
 
+/* Convenience wrapper around qmp_block_dirty_bitmap_merge */
+static void do_dirty_bitmap_merge(const char *dst_node, const char *dst_name,
+                                  const char *src_node, const char *src_name,
+                                  Error **errp)
+{
+    BlockDirtyBitmapMergeSource *merge_src;
+    BlockDirtyBitmapMergeSourceList *list;
+
+    merge_src = g_new0(BlockDirtyBitmapMergeSource, 1);
+    merge_src->type = QTYPE_QDICT;
+    merge_src->u.external.node = g_strdup(src_node);
+    merge_src->u.external.name = g_strdup(src_name);
+    list = g_new0(BlockDirtyBitmapMergeSourceList, 1);
+    list->value = merge_src;
+    qmp_block_dirty_bitmap_merge(dst_node, dst_name, list, errp);
+    qapi_free_BlockDirtyBitmapMergeSourceList(list);
+}
+
 enum ImgConvertBlockStatus {
     BLK_DATA,
     BLK_ZERO,
@@ -2121,6 +2141,39 @@ static int convert_do_copy(ImgConvertState *s)
     return s->ret;
 }
 
+static int convert_copy_bitmaps(BlockDriverState *src, BlockDriverState *dst)
+{
+    BdrvDirtyBitmap *bm;
+    Error *err = NULL;
+
+    FOR_EACH_DIRTY_BITMAP(src, bm) {
+        const char *name;
+
+        if (!bdrv_dirty_bitmap_get_persistence(bm)) {
+            continue;
+        }
+        name = bdrv_dirty_bitmap_name(bm);
+        qmp_block_dirty_bitmap_add(dst->node_name, name,
+                                   true, bdrv_dirty_bitmap_granularity(bm),
+                                   true, true,
+                                   true, !bdrv_dirty_bitmap_enabled(bm),
+                                   &err);
+        if (err) {
+            error_reportf_err(err, "Failed to create bitmap %s: ", name);
+            return -1;
+        }
+
+        do_dirty_bitmap_merge(dst->node_name, name, src->node_name, name,
+                              &err);
+        if (err) {
+            error_reportf_err(err, "Failed to populate bitmap %s: ", name);
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
 #define MAX_BUF_SECTORS 32768
 
 static int img_convert(int argc, char **argv)
@@ -2142,6 +2195,7 @@ static int img_convert(int argc, char **argv)
     int64_t ret = -EINVAL;
     bool force_share = false;
     bool explict_min_sparse = false;
+    bool bitmaps = false;
 
     ImgConvertState s = (ImgConvertState) {
         /* Need at least 4k of zeros for sparse detection */
@@ -2161,6 +2215,7 @@ static int img_convert(int argc, char **argv)
             {"target-image-opts", no_argument, 0, OPTION_TARGET_IMAGE_OPTS},
             {"salvage", no_argument, 0, OPTION_SALVAGE},
             {"target-is-zero", no_argument, 0, OPTION_TARGET_IS_ZERO},
+            {"bitmaps", no_argument, 0, OPTION_BITMAPS},
             {0, 0, 0, 0}
         };
         c = getopt_long(argc, argv, ":hf:O:B:Cco:l:S:pt:T:qnm:WU",
@@ -2286,6 +2341,9 @@ static int img_convert(int argc, char **argv)
              */
             s.has_zero_init = true;
             break;
+        case OPTION_BITMAPS:
+            bitmaps = true;
+            break;
         }
     }
 
@@ -2347,7 +2405,6 @@ static int img_convert(int argc, char **argv)
         goto fail_getopt;
     }
 
-
     /* ret is still -EINVAL until here */
     ret = bdrv_parse_cache_mode(src_cache, &src_flags, &src_writethrough);
     if (ret < 0) {
@@ -2507,6 +2564,20 @@ static int img_convert(int argc, char **argv)
         }
     }
 
+    /* Determine if bitmaps need copying */
+    if (bitmaps) {
+        if (s.src_num > 1) {
+            error_report("Copying bitmaps only possible with single source");
+            ret = -1;
+            goto out;
+        }
+        if (!bdrv_supports_persistent_dirty_bitmap(blk_bs(s.src[0]))) {
+            error_report("Source lacks bitmap support");
+            ret = -1;
+            goto out;
+        }
+    }
+
     /*
      * The later open call will need any decryption secrets, and
      * bdrv_create() will purge "opts", so extract them now before
@@ -2515,9 +2586,7 @@ static int img_convert(int argc, char **argv)
     if (!skip_create) {
         open_opts = qdict_new();
         qemu_opt_foreach(opts, img_add_key_secrets, open_opts, &error_abort);
-    }
 
-    if (!skip_create) {
         /* Create the new image */
         ret = bdrv_create(drv, out_filename, opts, &local_err);
         if (ret < 0) {
@@ -2555,6 +2624,13 @@ static int img_convert(int argc, char **argv)
     }
     out_bs = blk_bs(s.target);
 
+    if (bitmaps && !bdrv_supports_persistent_dirty_bitmap(out_bs)) {
+        error_report("Format driver '%s' does not support bitmaps",
+                     out_bs->drv->format_name);
+        ret = -1;
+        goto out;
+    }
+
     if (s.compressed && !block_driver_can_compress(out_bs->drv)) {
         error_report("Compression not supported for this file format");
         ret = -1;
@@ -2614,6 +2690,12 @@ static int img_convert(int argc, char **argv)
     }
 
     ret = convert_do_copy(&s);
+
+    /* Now copy the bitmaps */
+    if (bitmaps && ret == 0) {
+        ret = convert_copy_bitmaps(blk_bs(s.src[0]), out_bs);
+    }
+
 out:
     if (!ret) {
         qemu_progress_print(100, 0);
@@ -4714,21 +4796,11 @@ static int img_bitmap(int argc, char **argv)
             qmp_block_dirty_bitmap_disable(bs->node_name, bitmap, &err);
             op = "disable";
             break;
-        case BITMAP_MERGE: {
-            BlockDirtyBitmapMergeSource *merge_src;
-            BlockDirtyBitmapMergeSourceList *list;
-
-            merge_src = g_new0(BlockDirtyBitmapMergeSource, 1);
-            merge_src->type = QTYPE_QDICT;
-            merge_src->u.external.node = g_strdup(src_bs->node_name);
-            merge_src->u.external.name = g_strdup(act->src);
-            list = g_new0(BlockDirtyBitmapMergeSourceList, 1);
-            list->value = merge_src;
-            qmp_block_dirty_bitmap_merge(bs->node_name, bitmap, list, &err);
-            qapi_free_BlockDirtyBitmapMergeSourceList(list);
+        case BITMAP_MERGE:
+            do_dirty_bitmap_merge(bs->node_name, bitmap, src_bs->node_name,
+                                  act->src, &err);
             op = "merge";
             break;
-        }
         default:
             g_assert_not_reached();
         }
@@ -5302,6 +5374,9 @@ static int img_measure(int argc, char **argv)
     if (output_format == OFORMAT_HUMAN) {
         printf("required size: %" PRIu64 "\n", info->required);
         printf("fully allocated size: %" PRIu64 "\n", info->fully_allocated);
+        if (info->has_bitmaps) {
+            printf("bitmaps size: %" PRIu64 "\n", info->bitmaps);
+        }
     } else {
         dump_json_block_measure_info(info);
     }
diff --git a/tests/qemu-iotests/178.out.qcow2 b/tests/qemu-iotests/178.out.qcow2
index f59bf4b..c799776 100644
--- a/tests/qemu-iotests/178.out.qcow2
+++ b/tests/qemu-iotests/178.out.qcow2
@@ -13,7 +13,7 @@ qemu-img: Invalid option list: ,
 qemu-img: Invalid parameter 'snapshot.foo'
 qemu-img: Failed in parsing snapshot param 'snapshot.foo'
 qemu-img: --output must be used with human or json as argument.
-qemu-img: Image size must be less than 8 EiB!
+qemu-img: Invalid image size specified. Must be between 0 and 9223372036854775807.
 qemu-img: Unknown file format 'foo'
 
 == Size calculation for a new file (human) ==
@@ -37,6 +37,7 @@ qemu-img: The image size is too large (try using a larger cluster size)
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=0
 required size: 196608
 fully allocated size: 196608
+bitmaps size: 0
 
 converted image file size in bytes: 196608
 
@@ -45,6 +46,7 @@ converted image file size in bytes: 196608
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 required size: 393216
 fully allocated size: 1074135040
+bitmaps size: 0
 wrote 512/512 bytes at offset 512
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 wrote 65536/65536 bytes at offset 65536
@@ -53,6 +55,7 @@ wrote 64512/64512 bytes at offset 134217728
 63 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 required size: 589824
 fully allocated size: 1074135040
+bitmaps size: 0
 
 converted image file size in bytes: 524288
 
@@ -60,6 +63,7 @@ converted image file size in bytes: 524288
 
 required size: 524288
 fully allocated size: 1074135040
+bitmaps size: 0
 
 converted image file size in bytes: 458752
 
@@ -67,16 +71,19 @@ converted image file size in bytes: 458752
 
 required size: 1074135040
 fully allocated size: 1074135040
+bitmaps size: 0
 
 == qcow2 input image and LUKS encryption ==
 
 required size: 2686976
 fully allocated size: 1076232192
+bitmaps size: 0
 
 == qcow2 input image and preallocation (human) ==
 
 required size: 1074135040
 fully allocated size: 1074135040
+bitmaps size: 0
 
 converted image file size in bytes: 1074135040
 
@@ -87,6 +94,7 @@ wrote 8388608/8388608 bytes at offset 0
 8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 required size: 8716288
 fully allocated size: 8716288
+bitmaps size: 0
 
 converted image file size in bytes: 8716288
 
@@ -173,6 +181,7 @@ qemu-img: The image size is too large (try using a larger cluster size)
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=0
 {
+    "bitmaps": 0,
     "required": 196608,
     "fully-allocated": 196608
 }
@@ -183,6 +192,7 @@ converted image file size in bytes: 196608
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 {
+    "bitmaps": 0,
     "required": 393216,
     "fully-allocated": 1074135040
 }
@@ -193,6 +203,7 @@ wrote 65536/65536 bytes at offset 65536
 wrote 64512/64512 bytes at offset 134217728
 63 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 {
+    "bitmaps": 0,
     "required": 589824,
     "fully-allocated": 1074135040
 }
@@ -202,6 +213,7 @@ converted image file size in bytes: 524288
 == qcow2 input image with internal snapshot (json) ==
 
 {
+    "bitmaps": 0,
     "required": 524288,
     "fully-allocated": 1074135040
 }
@@ -211,6 +223,7 @@ converted image file size in bytes: 458752
 == qcow2 input image and a backing file (json) ==
 
 {
+    "bitmaps": 0,
     "required": 1074135040,
     "fully-allocated": 1074135040
 }
@@ -218,6 +231,7 @@ converted image file size in bytes: 458752
 == qcow2 input image and LUKS encryption ==
 
 {
+    "bitmaps": 0,
     "required": 2686976,
     "fully-allocated": 1076232192
 }
@@ -225,6 +239,7 @@ converted image file size in bytes: 458752
 == qcow2 input image and preallocation (json) ==
 
 {
+    "bitmaps": 0,
     "required": 1074135040,
     "fully-allocated": 1074135040
 }
@@ -237,6 +252,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=8388608
 wrote 8388608/8388608 bytes at offset 0
 8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 {
+    "bitmaps": 0,
     "required": 8716288,
     "fully-allocated": 8716288
 }
diff --git a/tests/qemu-iotests/178.out.raw b/tests/qemu-iotests/178.out.raw
index 404ca90..20e17da 100644
--- a/tests/qemu-iotests/178.out.raw
+++ b/tests/qemu-iotests/178.out.raw
@@ -13,7 +13,7 @@ qemu-img: Invalid option list: ,
 qemu-img: Invalid parameter 'snapshot.foo'
 qemu-img: Failed in parsing snapshot param 'snapshot.foo'
 qemu-img: --output must be used with human or json as argument.
-qemu-img: Image size must be less than 8 EiB!
+qemu-img: Invalid image size specified. Must be between 0 and 9223372036854775807.
 qemu-img: Unknown file format 'foo'
 
 == Size calculation for a new file (human) ==
diff --git a/tests/qemu-iotests/190 b/tests/qemu-iotests/190
index 6d416504..fe63091 100755
--- a/tests/qemu-iotests/190
+++ b/tests/qemu-iotests/190
@@ -2,7 +2,7 @@
 #
 # qemu-img measure sub-command tests on huge qcow2 files
 #
-# Copyright (C) 2017 Red Hat, Inc.
+# Copyright (C) 2017-2020 Red Hat, Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -42,7 +42,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto file
 
-echo "== Huge file =="
+echo "== Huge file without bitmaps =="
 echo
 
 _make_test_img -o 'cluster_size=2M' 2T
@@ -51,6 +51,49 @@ $QEMU_IMG measure -O raw -f qcow2 "$TEST_IMG"
 $QEMU_IMG measure -O qcow2 -o cluster_size=64k -f qcow2 "$TEST_IMG"
 $QEMU_IMG measure -O qcow2 -o cluster_size=2M -f qcow2 "$TEST_IMG"
 
+echo
+echo "== Huge file with bitmaps =="
+echo
+
+$QEMU_IMG bitmap --add --granularity 512 -f qcow2 "$TEST_IMG" b1
+$QEMU_IMG bitmap --add -g 2M -f qcow2 "$TEST_IMG" b2
+
+# No bitmap without a source
+$QEMU_IMG measure -O qcow2 --size 10M
+# No bitmap output, since raw does not support it
+$QEMU_IMG measure -O raw -f qcow2 "$TEST_IMG"
+# No bitmap output, since no bitmaps on raw source. Munge required size, as
+# some filesystems store the qcow2 file with less sparseness than others
+$QEMU_IMG measure -O qcow2 -f raw "$TEST_IMG" |
+    sed '/^required size:/ s/[0-9][0-9]*/SIZE/'
+# No bitmap output, since v2 does not support it
+$QEMU_IMG measure -O qcow2 -o compat=0.10 -f qcow2 "$TEST_IMG"
+
+# Compute expected output: bitmap clusters + bitmap tables + bitmaps directory
+echo
+val2T=$((2*1024*1024*1024*1024))
+cluster=$((64*1024))
+b1clusters=$(( (val2T/512/8 + cluster - 1) / cluster ))
+b2clusters=$(( (val2T/2/1024/1024/8 + cluster - 1) / cluster ))
+echo expected bitmap $((b1clusters * cluster +
+                        (b1clusters * 8 + cluster - 1) / cluster * cluster +
+                        b2clusters * cluster +
+                        (b2clusters * 8 + cluster - 1) / cluster * cluster +
+                        cluster))
+$QEMU_IMG measure -O qcow2 -o cluster_size=64k -f qcow2 "$TEST_IMG"
+
+# Compute expected output: bitmap clusters + bitmap tables + bitmaps directory
+echo
+cluster=$((2*1024*1024))
+b1clusters=$(( (val2T/512/8 + cluster - 1) / cluster ))
+b2clusters=$(( (val2T/2/1024/1024/8 + cluster - 1) / cluster ))
+echo expected bitmap $((b1clusters * cluster +
+                        (b1clusters * 8 + cluster - 1) / cluster * cluster +
+                        b2clusters * cluster +
+                        (b2clusters * 8 + cluster - 1) / cluster * cluster +
+                        cluster))
+$QEMU_IMG measure --output=json -O qcow2 -o cluster_size=2M -f qcow2 "$TEST_IMG"
+
 # success, all done
 echo "*** done"
 rm -f $seq.full
diff --git a/tests/qemu-iotests/190.out b/tests/qemu-iotests/190.out
index d001942..ed9d821 100644
--- a/tests/qemu-iotests/190.out
+++ b/tests/qemu-iotests/190.out
@@ -1,11 +1,36 @@
 QA output created by 190
-== Huge file ==
+== Huge file without bitmaps ==
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=2199023255552
 required size: 2199023255552
 fully allocated size: 2199023255552
 required size: 335806464
 fully allocated size: 2199359062016
+bitmaps size: 0
 required size: 18874368
 fully allocated size: 2199042129920
+bitmaps size: 0
+
+== Huge file with bitmaps ==
+
+required size: 327680
+fully allocated size: 10813440
+required size: 2199023255552
+fully allocated size: 2199023255552
+required size: SIZE
+fully allocated size: 17170432
+required size: 335806464
+fully allocated size: 2199359062016
+
+expected bitmap 537198592
+required size: 335806464
+fully allocated size: 2199359062016
+bitmaps size: 537198592
+
+expected bitmap 545259520
+{
+    "bitmaps": 545259520,
+    "required": 18874368,
+    "fully-allocated": 2199042129920
+}
 *** done
diff --git a/tests/qemu-iotests/194 b/tests/qemu-iotests/194
index 8b1f720..3fad7c6 100755
--- a/tests/qemu-iotests/194
+++ b/tests/qemu-iotests/194
@@ -42,6 +42,8 @@ with iotests.FilePath('source.img') as source_img_path, \
             .add_incoming('unix:{0}'.format(migration_sock_path))
             .launch())
 
+    source_vm.qmp_log('block-dirty-bitmap-add', node='drive0', name='bitmap0')
+
     iotests.log('Launching NBD server on destination...')
     iotests.log(dest_vm.qmp('nbd-server-start', addr={'type': 'unix', 'data': {'path': nbd_sock_path}}))
     iotests.log(dest_vm.qmp('nbd-server-add', device='drive0', writable=True))
@@ -61,12 +63,14 @@ with iotests.FilePath('source.img') as source_img_path, \
                 filters=[iotests.filter_qmp_event])
 
     iotests.log('Starting migration...')
-    source_vm.qmp('migrate-set-capabilities',
-                  capabilities=[{'capability': 'events', 'state': True}])
-    dest_vm.qmp('migrate-set-capabilities',
-                capabilities=[{'capability': 'events', 'state': True}])
+    capabilities = [{'capability': 'events', 'state': True},
+                    {'capability': 'dirty-bitmaps', 'state': True}]
+    source_vm.qmp('migrate-set-capabilities', capabilities=capabilities)
+    dest_vm.qmp('migrate-set-capabilities', capabilities=capabilities)
     iotests.log(source_vm.qmp('migrate', uri='unix:{0}'.format(migration_sock_path)))
 
+    source_vm.qmp_log('migrate-start-postcopy')
+
     while True:
         event1 = source_vm.event_wait('MIGRATION')
         iotests.log(event1, filters=[iotests.filter_qmp_event])
@@ -82,3 +86,5 @@ with iotests.FilePath('source.img') as source_img_path, \
             iotests.log('Stopping the NBD server on destination...')
             iotests.log(dest_vm.qmp('nbd-server-stop'))
             break
+
+    iotests.log(source_vm.qmp('query-block')['return'][0]['dirty-bitmaps'])
diff --git a/tests/qemu-iotests/194.out b/tests/qemu-iotests/194.out
index 7185785..dd60dcc 100644
--- a/tests/qemu-iotests/194.out
+++ b/tests/qemu-iotests/194.out
@@ -1,4 +1,6 @@
 Launching VMs...
+{"execute": "block-dirty-bitmap-add", "arguments": {"name": "bitmap0", "node": "drive0"}}
+{"return": {}}
 Launching NBD server on destination...
 {"return": {}}
 {"return": {}}
@@ -8,11 +10,15 @@ Waiting for `drive-mirror` to complete...
 {"data": {"device": "mirror-job0", "len": 1073741824, "offset": 1073741824, "speed": 0, "type": "mirror"}, "event": "BLOCK_JOB_READY", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 Starting migration...
 {"return": {}}
+{"execute": "migrate-start-postcopy", "arguments": {}}
+{"return": {}}
 {"data": {"status": "setup"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"status": "active"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+{"data": {"status": "postcopy-active"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"status": "completed"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 Gracefully ending the `drive-mirror` job on source...
 {"return": {}}
 {"data": {"device": "mirror-job0", "len": 1073741824, "offset": 1073741824, "speed": 0, "type": "mirror"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 Stopping the NBD server on destination...
 {"return": {}}
+[{"busy": false, "count": 0, "granularity": 65536, "name": "bitmap0", "persistent": false, "recording": true, "status": "active"}]
diff --git a/tests/qemu-iotests/291 b/tests/qemu-iotests/291
new file mode 100755
index 0000000..3ca83b9
--- /dev/null
+++ b/tests/qemu-iotests/291
@@ -0,0 +1,112 @@
+#!/usr/bin/env bash
+#
+# Test qemu-img bitmap handling
+#
+# Copyright (C) 2018-2020 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+seq="$(basename $0)"
+echo "QA output created by $seq"
+
+status=1 # failure is the default!
+
+_cleanup()
+{
+    _cleanup_test_img
+    nbd_server_stop
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+. ./common.nbd
+
+_supported_fmt qcow2
+_supported_proto file
+_supported_os Linux
+_require_command QEMU_NBD
+
+echo
+echo "=== Initial image setup ==="
+echo
+
+# Create backing image with one bitmap
+TEST_IMG="$TEST_IMG.base" _make_test_img 10M
+$QEMU_IMG bitmap --add -f $IMGFMT "$TEST_IMG.base" b0
+$QEMU_IO -c 'w 3M 1M' -f $IMGFMT "$TEST_IMG.base" | _filter_qemu_io
+
+# Create initial image and populate two bitmaps: one active, one inactive.
+ORIG_IMG=$TEST_IMG
+TEST_IMG=$TEST_IMG.orig
+_make_test_img -b "$ORIG_IMG.base" -F $IMGFMT 10M
+$QEMU_IO -c 'w 0 1M' -f $IMGFMT "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG bitmap --add -g 512k -f $IMGFMT "$TEST_IMG" b1
+$QEMU_IMG bitmap --add --disable -f $IMGFMT "$TEST_IMG" b2
+$QEMU_IO -c 'w 3M 1M' -f $IMGFMT "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG bitmap --clear -f $IMGFMT "$TEST_IMG" b1
+$QEMU_IO -c 'w 1M 1M' -f $IMGFMT "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG bitmap --disable -f $IMGFMT "$TEST_IMG" b1
+$QEMU_IMG bitmap --enable -f $IMGFMT "$TEST_IMG" b2
+$QEMU_IO -c 'w 2M 1M' -f $IMGFMT "$TEST_IMG" | _filter_qemu_io
+
+echo
+echo "=== Bitmap preservation not possible to non-qcow2 ==="
+echo
+
+TEST_IMG=$ORIG_IMG
+$QEMU_IMG convert --bitmaps -O raw "$TEST_IMG.orig" "$TEST_IMG" &&
+    echo "unexpected success"
+
+echo
+echo "=== Convert with bitmap preservation ==="
+echo
+
+# Only bitmaps from the active layer are copied
+$QEMU_IMG convert --bitmaps -O qcow2 "$TEST_IMG.orig" "$TEST_IMG"
+$QEMU_IMG info "$TEST_IMG" | _filter_img_info --format-specific
+# But we can also merge in bitmaps from other layers.  This test is a bit
+# contrived to cover more code paths, in reality, you could merge directly
+# into b0 without going through tmp
+$QEMU_IMG bitmap --add --disable -f $IMGFMT "$TEST_IMG" b0
+$QEMU_IMG bitmap --add --merge b0 -b "$TEST_IMG.base" -F $IMGFMT \
+     -f $IMGFMT "$TEST_IMG" tmp
+$QEMU_IMG bitmap --merge tmp -f $IMGFMT "$TEST_IMG" b0
+$QEMU_IMG bitmap --remove --image-opts \
+    driver=$IMGFMT,file.driver=file,file.filename="$TEST_IMG" tmp
+$QEMU_IMG info "$TEST_IMG" | _filter_img_info --format-specific
+
+echo
+echo "=== Check bitmap contents ==="
+echo
+
+# x-dirty-bitmap is a hack for reading bitmaps; it abuses block status to
+# report "data":false for portions of the bitmap which are set
+IMG="driver=nbd,server.type=unix,server.path=$nbd_unix_socket"
+nbd_server_start_unix_socket -r -f qcow2 -B b0 "$TEST_IMG"
+$QEMU_IMG map --output=json --image-opts \
+    "$IMG,x-dirty-bitmap=qemu:dirty-bitmap:b0" | _filter_qemu_img_map
+nbd_server_start_unix_socket -r -f qcow2 -B b1 "$TEST_IMG"
+$QEMU_IMG map --output=json --image-opts \
+    "$IMG,x-dirty-bitmap=qemu:dirty-bitmap:b1" | _filter_qemu_img_map
+nbd_server_start_unix_socket -r -f qcow2 -B b2 "$TEST_IMG"
+$QEMU_IMG map --output=json --image-opts \
+    "$IMG,x-dirty-bitmap=qemu:dirty-bitmap:b2" | _filter_qemu_img_map
+
+# success, all done
+echo '*** done'
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/291.out b/tests/qemu-iotests/291.out
new file mode 100644
index 0000000..8c62017
--- /dev/null
+++ b/tests/qemu-iotests/291.out
@@ -0,0 +1,80 @@
+QA output created by 291
+
+=== Initial image setup ===
+
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=10485760
+wrote 1048576/1048576 bytes at offset 3145728
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Formatting 'TEST_DIR/t.IMGFMT.orig', fmt=IMGFMT size=10485760 backing_file=TEST_DIR/t.IMGFMT.base backing_fmt=IMGFMT
+wrote 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 1048576/1048576 bytes at offset 3145728
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 1048576/1048576 bytes at offset 1048576
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 1048576/1048576 bytes at offset 2097152
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+=== Bitmap preservation not possible to non-qcow2 ===
+
+qemu-img: Format driver 'raw' does not support bitmaps
+
+=== Convert with bitmap preservation ===
+
+image: TEST_DIR/t.IMGFMT
+file format: IMGFMT
+virtual size: 10 MiB (10485760 bytes)
+disk size: 4.39 MiB
+Format specific information:
+    compat: 1.1
+    compression type: zlib
+    lazy refcounts: false
+    bitmaps:
+        [0]:
+            flags:
+            name: b1
+            granularity: 524288
+        [1]:
+            flags:
+                [0]: auto
+            name: b2
+            granularity: 65536
+    refcount bits: 16
+    corrupt: false
+image: TEST_DIR/t.IMGFMT
+file format: IMGFMT
+virtual size: 10 MiB (10485760 bytes)
+disk size: 4.48 MiB
+Format specific information:
+    compat: 1.1
+    compression type: zlib
+    lazy refcounts: false
+    bitmaps:
+        [0]:
+            flags:
+            name: b1
+            granularity: 524288
+        [1]:
+            flags:
+                [0]: auto
+            name: b2
+            granularity: 65536
+        [2]:
+            flags:
+            name: b0
+            granularity: 65536
+    refcount bits: 16
+    corrupt: false
+
+=== Check bitmap contents ===
+
+[{ "start": 0, "length": 3145728, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
+{ "start": 3145728, "length": 1048576, "depth": 0, "zero": false, "data": false},
+{ "start": 4194304, "length": 6291456, "depth": 0, "zero": false, "data": true, "offset": OFFSET}]
+[{ "start": 0, "length": 1048576, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
+{ "start": 1048576, "length": 1048576, "depth": 0, "zero": false, "data": false},
+{ "start": 2097152, "length": 8388608, "depth": 0, "zero": false, "data": true, "offset": OFFSET}]
+[{ "start": 0, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
+{ "start": 2097152, "length": 1048576, "depth": 0, "zero": false, "data": false},
+{ "start": 3145728, "length": 7340032, "depth": 0, "zero": false, "data": true, "offset": OFFSET}]
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 445c26f..d886fa0 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -299,5 +299,6 @@
 288 quick
 289 rw quick
 290 rw auto quick
+291 rw quick
 292 rw auto quick
 297 meta