diff --git a/block/nbd-client.c b/block/nbd-client.c
index 8d69eaaa32..9686ecbd5e 100644
--- a/block/nbd-client.c
+++ b/block/nbd-client.c
@@ -970,6 +970,7 @@ int nbd_client_init(BlockDriverState *bs,
                     const char *export,
                     QCryptoTLSCreds *tlscreds,
                     const char *hostname,
+                    const char *x_dirty_bitmap,
                     Error **errp)
 {
     NBDClientSession *client = nbd_get_client_session(bs);
@@ -982,9 +983,11 @@ int nbd_client_init(BlockDriverState *bs,
     client->info.request_sizes = true;
     client->info.structured_reply = true;
     client->info.base_allocation = true;
+    client->info.x_dirty_bitmap = g_strdup(x_dirty_bitmap);
     ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), export,
                                 tlscreds, hostname,
                                 &client->ioc, &client->info, errp);
+    g_free(client->info.x_dirty_bitmap);
     if (ret < 0) {
         logout("Failed to negotiate with the NBD server\n");
         return ret;
diff --git a/block/nbd-client.h b/block/nbd-client.h
index 0ece76e5af..cfc90550b9 100644
--- a/block/nbd-client.h
+++ b/block/nbd-client.h
@@ -45,6 +45,7 @@ int nbd_client_init(BlockDriverState *bs,
                     const char *export_name,
                     QCryptoTLSCreds *tlscreds,
                     const char *hostname,
+                    const char *x_dirty_bitmap,
                     Error **errp);
 void nbd_client_close(BlockDriverState *bs);
 
diff --git a/block/nbd.c b/block/nbd.c
index 13db4030e6..b198ad775f 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -378,6 +378,12 @@ static QemuOptsList nbd_runtime_opts = {
             .type = QEMU_OPT_STRING,
             .help = "ID of the TLS credentials to use",
         },
+        {
+            .name = "x-dirty-bitmap",
+            .type = QEMU_OPT_STRING,
+            .help = "experimental: expose named dirty bitmap in place of "
+                    "block status",
+        },
         { /* end of list */ }
     },
 };
@@ -438,8 +444,8 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
     }
 
     /* NBD handshake */
-    ret = nbd_client_init(bs, sioc, s->export,
-                          tlscreds, hostname, errp);
+    ret = nbd_client_init(bs, sioc, s->export, tlscreds, hostname,
+                          qemu_opt_get(opts, "x-dirty-bitmap"), errp);
  error:
     if (sioc) {
         object_unref(OBJECT(sioc));
diff --git a/include/block/nbd.h b/include/block/nbd.h
index daaeae61bf..4638c839f5 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -259,6 +259,7 @@ static inline bool nbd_reply_type_is_error(int type)
 struct NBDExportInfo {
     /* Set by client before nbd_receive_negotiate() */
     bool request_sizes;
+    char *x_dirty_bitmap;
 
     /* In-out fields, set by client before nbd_receive_negotiate() and
      * updated by server results during nbd_receive_negotiate() */
diff --git a/nbd/client.c b/nbd/client.c
index 232ff4f46d..40b74d9761 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -1,5 +1,5 @@
 /*
- *  Copyright (C) 2016-2017 Red Hat, Inc.
+ *  Copyright (C) 2016-2018 Red Hat, Inc.
  *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
  *
  *  Network Block Device Client Side
@@ -831,7 +831,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
 
             if (info->structured_reply && base_allocation) {
                 result = nbd_negotiate_simple_meta_context(
-                        ioc, name, "base:allocation",
+                        ioc, name, info->x_dirty_bitmap ?: "base:allocation",
                         &info->meta_base_allocation_id, errp);
                 if (result < 0) {
                     goto fail;
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 577ce5e999..90e554ed0f 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -3471,12 +3471,17 @@
 #
 # @tls-creds:   TLS credentials ID
 #
+# @x-dirty-bitmap: A "qemu:dirty-bitmap:NAME" string to query in place of
+#                  traditional "base:allocation" block status (see
+#                  NBD_OPT_LIST_META_CONTEXT in the NBD protocol) (since 3.0)
+#
 # Since: 2.9
 ##
 { 'struct': 'BlockdevOptionsNbd',
   'data': { 'server': 'SocketAddress',
             '*export': 'str',
-            '*tls-creds': 'str' } }
+            '*tls-creds': 'str',
+            '*x-dirty-bitmap': 'str' } }
 
 ##
 # @BlockdevOptionsRaw: