diff --git a/block/bochs.c b/block/bochs.c
index 32bb83b268ed..e7bbeaa1c45d 100644
--- a/block/bochs.c
+++ b/block/bochs.c
@@ -301,6 +301,7 @@ static BlockDriver bdrv_bochs = {
     .bdrv_refresh_limits = bochs_refresh_limits,
     .bdrv_co_preadv = bochs_co_preadv,
     .bdrv_close		= bochs_close,
+    .is_format          = true,
 };
 
 static void bdrv_bochs_init(void)
diff --git a/block/cloop.c b/block/cloop.c
index 4de94876d4f0..f90f1a4b4c86 100644
--- a/block/cloop.c
+++ b/block/cloop.c
@@ -297,6 +297,7 @@ static BlockDriver bdrv_cloop = {
     .bdrv_refresh_limits = cloop_refresh_limits,
     .bdrv_co_preadv = cloop_co_preadv,
     .bdrv_close     = cloop_close,
+    .is_format      = true,
 };
 
 static void bdrv_cloop_init(void)
diff --git a/block/crypto.c b/block/crypto.c
index 6b21d6bf6c01..bdb2b27475d6 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -771,6 +771,8 @@ static BlockDriver bdrv_crypto_luks = {
     .bdrv_get_info      = block_crypto_get_info_luks,
     .bdrv_get_specific_info = block_crypto_get_specific_info_luks,
 
+    .is_format          = true,
+
     .strong_runtime_opts = block_crypto_strong_runtime_opts,
 };
 
diff --git a/block/dmg.c b/block/dmg.c
index 4a045f2b3e0f..ef3c6e771d76 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -753,6 +753,7 @@ static BlockDriver bdrv_dmg = {
     .bdrv_child_perm     = bdrv_format_default_perms,
     .bdrv_co_preadv = dmg_co_preadv,
     .bdrv_close     = dmg_close,
+    .is_format      = true,
 };
 
 static void bdrv_dmg_init(void)
diff --git a/block/parallels.c b/block/parallels.c
index e7717c508e62..bd5f6ffa09aa 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -918,6 +918,7 @@ static BlockDriver bdrv_parallels = {
     .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
     .bdrv_co_readv  = parallels_co_readv,
     .bdrv_co_writev = parallels_co_writev,
+    .is_format      = true,
     .supports_backing = true,
     .bdrv_co_create      = parallels_co_create,
     .bdrv_co_create_opts = parallels_co_create_opts,
diff --git a/block/qcow.c b/block/qcow.c
index b0475b73a551..6a72dea049e3 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -1185,6 +1185,7 @@ static BlockDriver bdrv_qcow = {
     .bdrv_co_create         = qcow_co_create,
     .bdrv_co_create_opts    = qcow_co_create_opts,
     .bdrv_has_zero_init     = bdrv_has_zero_init_1,
+    .is_format              = true,
     .supports_backing       = true,
     .bdrv_refresh_limits    = qcow_refresh_limits,
 
diff --git a/block/qcow2.c b/block/qcow2.c
index ad9ab4fafa00..76bec61ee940 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -5767,6 +5767,7 @@ BlockDriver bdrv_qcow2 = {
     .bdrv_save_vmstate    = qcow2_save_vmstate,
     .bdrv_load_vmstate    = qcow2_load_vmstate,
 
+    .is_format                  = true,
     .supports_backing           = true,
     .bdrv_change_backing_file   = qcow2_change_backing_file,
 
diff --git a/block/qed.c b/block/qed.c
index 5da9726518df..337eb6dbb6b7 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1665,6 +1665,7 @@ static BlockDriver bdrv_qed = {
     .format_name              = "qed",
     .instance_size            = sizeof(BDRVQEDState),
     .create_opts              = &qed_create_opts,
+    .is_format                = true,
     .supports_backing         = true,
 
     .bdrv_probe               = bdrv_qed_probe,
diff --git a/block/raw-format.c b/block/raw-format.c
index 9108e4369628..00e13bb41e76 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -566,6 +566,7 @@ BlockDriver bdrv_raw = {
     .bdrv_co_copy_range_to  = &raw_co_copy_range_to,
     .bdrv_co_truncate     = &raw_co_truncate,
     .bdrv_getlength       = &raw_getlength,
+    .is_format            = true,
     .has_variable_length  = true,
     .bdrv_measure         = &raw_measure,
     .bdrv_get_info        = &raw_get_info,
diff --git a/block/vdi.c b/block/vdi.c
index 2d2804661527..0ef733ae190c 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -1053,6 +1053,7 @@ static BlockDriver bdrv_vdi = {
 
     .bdrv_get_info = vdi_get_info,
 
+    .is_format = true,
     .create_opts = &vdi_create_opts,
     .bdrv_co_check = vdi_co_check,
 };
diff --git a/block/vhdx.c b/block/vhdx.c
index 53e756438ac4..e692cf80ccae 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -2254,6 +2254,7 @@ static BlockDriver bdrv_vhdx = {
     .bdrv_co_check          = vhdx_co_check,
     .bdrv_has_zero_init     = vhdx_has_zero_init,
 
+    .is_format              = true,
     .create_opts            = &vhdx_create_opts,
 };
 
diff --git a/block/vmdk.c b/block/vmdk.c
index b18f12881636..56e85689f3fe 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -3070,6 +3070,7 @@ static BlockDriver bdrv_vmdk = {
     .bdrv_get_info                = vmdk_get_info,
     .bdrv_gather_child_options    = vmdk_gather_child_options,
 
+    .is_format                    = true,
     .supports_backing             = true,
     .create_opts                  = &vmdk_create_opts,
 };
diff --git a/block/vpc.c b/block/vpc.c
index 5e31dd1e47a1..46a2d4865985 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -1250,6 +1250,7 @@ static BlockDriver bdrv_vpc = {
 
     .bdrv_get_info          = vpc_get_info,
 
+    .is_format              = true,
     .create_opts            = &vpc_create_opts,
     .bdrv_has_zero_init     = vpc_has_zero_init,
     .strong_runtime_opts    = vpc_strong_runtime_opts,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 7ba8c8903609..1c24df53fd46 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -95,6 +95,13 @@ struct BlockDriver {
      * must implement them and return -ENOTSUP.
      */
     bool is_filter;
+    /*
+     * Set to true if the BlockDriver is a format driver.  Format nodes
+     * generally do not expect their children to be other format nodes
+     * (except for backing files), and so format probing is disabled
+     * on those children.
+     */
+    bool is_format;
     /*
      * Return true if @to_replace can be replaced by a BDS with the
      * same data as @bs without it affecting @bs's behavior (that is,