Merge remote-tracking branch 'remotes/ericb/tags/pull-bitmaps-2020-05-18-v3' into staging

bitmaps patches for 2020-05-18

- update bitmaps maintainers
- add 'qemu-img bitmap' subcommand

# gpg: Signature made Tue 19 May 2020 18:53:59 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-2020-05-18-v3:
  qemu-img: Add bitmap sub-command
  blockdev: Split off basic bitmap operations for qemu-img
  blockdev: Promote several bitmap functions to non-static
  block: Make it easier to learn which BDS support bitmaps
  qemu-img: Fix stale comments on doc location
  docs: Sort sections on qemu-img subcommand parameters
  bitmaps: Update maintainer

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

14 files changed, 671 insertions, 329 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 47ef3139e6..87a412c229 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2011,19 +2011,21 @@ F: qapi/transaction.json
 T: git https://repo.or.cz/qemu/armbru.git block-next
 
 Dirty Bitmaps
-M: John Snow <jsnow@redhat.com>
-R: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
+M: Eric Blake <eblake@redhat.com>
+M: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
+R: John Snow <jsnow@redhat.com>
 L: qemu-block@nongnu.org
 S: Supported
 F: include/qemu/hbitmap.h
 F: include/block/dirty-bitmap.h
+F: block/monitor/bitmap-qmp-cmds.c
 F: block/dirty-bitmap.c
 F: block/qcow2-bitmap.c
 F: migration/block-dirty-bitmap.c
 F: util/hbitmap.c
 F: tests/test-hbitmap.c
 F: docs/interop/bitmaps.rst
-T: git https://github.com/jnsnow/qemu.git bitmaps
+T: git https://repo.or.cz/qemu/ericb.git bitmaps
 
 Character device backends
 M: Marc-André Lureau <marcandre.lureau@redhat.com>
diff --git a/Makefile.objs b/Makefile.objs
index a7c967633a..99774cfd25 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -13,9 +13,8 @@ chardev-obj-y = chardev/
 
 authz-obj-y = authz/
 
-block-obj-y = nbd/
+block-obj-y = block/ block/monitor/ nbd/ scsi/
 block-obj-y += block.o blockjob.o job.o
-block-obj-y += block/ scsi/
 block-obj-y += qemu-io-cmds.o
 block-obj-$(CONFIG_REPLICATION) += replication.o
 
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 063793e316..f9bfc77985 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -478,6 +478,15 @@ int bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *name,
     }
 }
 
+bool
+bdrv_supports_persistent_dirty_bitmap(BlockDriverState *bs)
+{
+    if (bs->drv && bs->drv->bdrv_supports_persistent_dirty_bitmap) {
+        return bs->drv->bdrv_supports_persistent_dirty_bitmap(bs);
+    }
+    return false;
+}
+
 static bool coroutine_fn
 bdrv_co_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
                                    uint32_t granularity, Error **errp)
diff --git a/block/monitor/Makefile.objs b/block/monitor/Makefile.objs
index 0a74f9a8b5..39acf85022 100644
--- a/block/monitor/Makefile.objs
+++ b/block/monitor/Makefile.objs
@@ -1 +1,2 @@
 common-obj-y += block-hmp-cmds.o
+block-obj-y += bitmap-qmp-cmds.o
diff --git a/block/monitor/bitmap-qmp-cmds.c b/block/monitor/bitmap-qmp-cmds.c
new file mode 100644
index 0000000000..9f11deec64
--- /dev/null
+++ b/block/monitor/bitmap-qmp-cmds.c
@@ -0,0 +1,321 @@
+/*
+ * QEMU block dirty bitmap QMP commands
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ *
+ * This file incorporates work covered by the following copyright and
+ * permission notice:
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+
+#include "block/block_int.h"
+#include "qapi/qapi-commands-block.h"
+#include "qapi/error.h"
+
+/**
+ * block_dirty_bitmap_lookup:
+ * Return a dirty bitmap (if present), after validating
+ * the node reference and bitmap names.
+ *
+ * @node: The name of the BDS node to search for bitmaps
+ * @name: The name of the bitmap to search for
+ * @pbs: Output pointer for BDS lookup, if desired. Can be NULL.
+ * @errp: Output pointer for error information. Can be NULL.
+ *
+ * @return: A bitmap object on success, or NULL on failure.
+ */
+BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node,
+                                           const char *name,
+                                           BlockDriverState **pbs,
+                                           Error **errp)
+{
+    BlockDriverState *bs;
+    BdrvDirtyBitmap *bitmap;
+
+    if (!node) {
+        error_setg(errp, "Node cannot be NULL");
+        return NULL;
+    }
+    if (!name) {
+        error_setg(errp, "Bitmap name cannot be NULL");
+        return NULL;
+    }
+    bs = bdrv_lookup_bs(node, node, NULL);
+    if (!bs) {
+        error_setg(errp, "Node '%s' not found", node);
+        return NULL;
+    }
+
+    bitmap = bdrv_find_dirty_bitmap(bs, name);
+    if (!bitmap) {
+        error_setg(errp, "Dirty bitmap '%s' not found", name);
+        return NULL;
+    }
+
+    if (pbs) {
+        *pbs = bs;
+    }
+
+    return bitmap;
+}
+
+void qmp_block_dirty_bitmap_add(const char *node, const char *name,
+                                bool has_granularity, uint32_t granularity,
+                                bool has_persistent, bool persistent,
+                                bool has_disabled, bool disabled,
+                                Error **errp)
+{
+    BlockDriverState *bs;
+    BdrvDirtyBitmap *bitmap;
+    AioContext *aio_context;
+
+    if (!name || name[0] == '\0') {
+        error_setg(errp, "Bitmap name cannot be empty");
+        return;
+    }
+
+    bs = bdrv_lookup_bs(node, node, errp);
+    if (!bs) {
+        return;
+    }
+
+    aio_context = bdrv_get_aio_context(bs);
+    aio_context_acquire(aio_context);
+
+    if (has_granularity) {
+        if (granularity < 512 || !is_power_of_2(granularity)) {
+            error_setg(errp, "Granularity must be power of 2 "
+                             "and at least 512");
+            goto out;
+        }
+    } else {
+        /* Default to cluster size, if available: */
+        granularity = bdrv_get_default_bitmap_granularity(bs);
+    }
+
+    if (!has_persistent) {
+        persistent = false;
+    }
+
+    if (!has_disabled) {
+        disabled = false;
+    }
+
+    if (persistent &&
+        !bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp))
+    {
+        goto out;
+    }
+
+    bitmap = bdrv_create_dirty_bitmap(bs, granularity, name, errp);
+    if (bitmap == NULL) {
+        goto out;
+    }
+
+    if (disabled) {
+        bdrv_disable_dirty_bitmap(bitmap);
+    }
+
+    bdrv_dirty_bitmap_set_persistence(bitmap, persistent);
+
+out:
+    aio_context_release(aio_context);
+}
+
+BdrvDirtyBitmap *block_dirty_bitmap_remove(const char *node, const char *name,
+                                           bool release,
+                                           BlockDriverState **bitmap_bs,
+                                           Error **errp)
+{
+    BlockDriverState *bs;
+    BdrvDirtyBitmap *bitmap;
+    AioContext *aio_context;
+
+    bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
+    if (!bitmap || !bs) {
+        return NULL;
+    }
+
+    aio_context = bdrv_get_aio_context(bs);
+    aio_context_acquire(aio_context);
+
+    if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_BUSY | BDRV_BITMAP_RO,
+                                errp)) {
+        aio_context_release(aio_context);
+        return NULL;
+    }
+
+    if (bdrv_dirty_bitmap_get_persistence(bitmap) &&
+        bdrv_remove_persistent_dirty_bitmap(bs, name, errp) < 0)
+    {
+        aio_context_release(aio_context);
+        return NULL;
+    }
+
+    if (release) {
+        bdrv_release_dirty_bitmap(bitmap);
+    }
+
+    if (bitmap_bs) {
+        *bitmap_bs = bs;
+    }
+
+    aio_context_release(aio_context);
+    return release ? NULL : bitmap;
+}
+
+void qmp_block_dirty_bitmap_remove(const char *node, const char *name,
+                                   Error **errp)
+{
+    block_dirty_bitmap_remove(node, name, true, NULL, errp);
+}
+
+/**
+ * Completely clear a bitmap, for the purposes of synchronizing a bitmap
+ * immediately after a full backup operation.
+ */
+void qmp_block_dirty_bitmap_clear(const char *node, const char *name,
+                                  Error **errp)
+{
+    BdrvDirtyBitmap *bitmap;
+    BlockDriverState *bs;
+
+    bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
+    if (!bitmap || !bs) {
+        return;
+    }
+
+    if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, errp)) {
+        return;
+    }
+
+    bdrv_clear_dirty_bitmap(bitmap, NULL);
+}
+
+void qmp_block_dirty_bitmap_enable(const char *node, const char *name,
+                                   Error **errp)
+{
+    BlockDriverState *bs;
+    BdrvDirtyBitmap *bitmap;
+
+    bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
+    if (!bitmap) {
+        return;
+    }
+
+    if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
+        return;
+    }
+
+    bdrv_enable_dirty_bitmap(bitmap);
+}
+
+void qmp_block_dirty_bitmap_disable(const char *node, const char *name,
+                                    Error **errp)
+{
+    BlockDriverState *bs;
+    BdrvDirtyBitmap *bitmap;
+
+    bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
+    if (!bitmap) {
+        return;
+    }
+
+    if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
+        return;
+    }
+
+    bdrv_disable_dirty_bitmap(bitmap);
+}
+
+BdrvDirtyBitmap *block_dirty_bitmap_merge(const char *node, const char *target,
+                                          BlockDirtyBitmapMergeSourceList *bms,
+                                          HBitmap **backup, Error **errp)
+{
+    BlockDriverState *bs;
+    BdrvDirtyBitmap *dst, *src, *anon;
+    BlockDirtyBitmapMergeSourceList *lst;
+    Error *local_err = NULL;
+
+    dst = block_dirty_bitmap_lookup(node, target, &bs, errp);
+    if (!dst) {
+        return NULL;
+    }
+
+    anon = bdrv_create_dirty_bitmap(bs, bdrv_dirty_bitmap_granularity(dst),
+                                    NULL, errp);
+    if (!anon) {
+        return NULL;
+    }
+
+    for (lst = bms; lst; lst = lst->next) {
+        switch (lst->value->type) {
+            const char *name, *node;
+        case QTYPE_QSTRING:
+            name = lst->value->u.local;
+            src = bdrv_find_dirty_bitmap(bs, name);
+            if (!src) {
+                error_setg(errp, "Dirty bitmap '%s' not found", name);
+                dst = NULL;
+                goto out;
+            }
+            break;
+        case QTYPE_QDICT:
+            node = lst->value->u.external.node;
+            name = lst->value->u.external.name;
+            src = block_dirty_bitmap_lookup(node, name, NULL, errp);
+            if (!src) {
+                dst = NULL;
+                goto out;
+            }
+            break;
+        default:
+            abort();
+        }
+
+        bdrv_merge_dirty_bitmap(anon, src, NULL, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            dst = NULL;
+            goto out;
+        }
+    }
+
+    /* Merge into dst; dst is unchanged on failure. */
+    bdrv_merge_dirty_bitmap(dst, anon, backup, errp);
+
+ out:
+    bdrv_release_dirty_bitmap(anon);
+    return dst;
+}
+
+void qmp_block_dirty_bitmap_merge(const char *node, const char *target,
+                                  BlockDirtyBitmapMergeSourceList *bitmaps,
+                                  Error **errp)
+{
+    block_dirty_bitmap_merge(node, target, bitmaps, NULL, errp);
+}
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index cb06954b4a..1cf6d2ab77 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1748,3 +1748,10 @@ fail:
                   name, bdrv_get_device_or_node_name(bs));
     return false;
 }
+
+bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs)
+{
+    BDRVQcow2State *s = bs->opaque;
+
+    return s->qcow_version >= 3;
+}
diff --git a/block/qcow2.c b/block/qcow2.c
index fe0ce39799..dfab8d2f6c 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -5791,6 +5791,8 @@ BlockDriver bdrv_qcow2 = {
     .bdrv_detach_aio_context  = qcow2_detach_aio_context,
     .bdrv_attach_aio_context  = qcow2_attach_aio_context,
 
+    .bdrv_supports_persistent_dirty_bitmap =
+            qcow2_supports_persistent_dirty_bitmap,
     .bdrv_co_can_store_new_dirty_bitmap = qcow2_co_can_store_new_dirty_bitmap,
     .bdrv_co_remove_persistent_dirty_bitmap =
             qcow2_co_remove_persistent_dirty_bitmap,
diff --git a/block/qcow2.h b/block/qcow2.h
index 6a8b82e6cc..402e8acb1c 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -782,6 +782,7 @@ bool qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
 int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
                                             const char *name,
                                             Error **errp);
+bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs);
 
 ssize_t coroutine_fn
 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
diff --git a/blockdev.c b/blockdev.c
index b3c840ec03..72df193ca7 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1185,53 +1185,6 @@ out_aio_context:
     return NULL;
 }
 
-/**
- * block_dirty_bitmap_lookup:
- * Return a dirty bitmap (if present), after validating
- * the node reference and bitmap names.
- *
- * @node: The name of the BDS node to search for bitmaps
- * @name: The name of the bitmap to search for
- * @pbs: Output pointer for BDS lookup, if desired. Can be NULL.
- * @errp: Output pointer for error information. Can be NULL.
- *
- * @return: A bitmap object on success, or NULL on failure.
- */
-static BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node,
-                                                  const char *name,
-                                                  BlockDriverState **pbs,
-                                                  Error **errp)
-{
-    BlockDriverState *bs;
-    BdrvDirtyBitmap *bitmap;
-
-    if (!node) {
-        error_setg(errp, "Node cannot be NULL");
-        return NULL;
-    }
-    if (!name) {
-        error_setg(errp, "Bitmap name cannot be NULL");
-        return NULL;
-    }
-    bs = bdrv_lookup_bs(node, node, NULL);
-    if (!bs) {
-        error_setg(errp, "Node '%s' not found", node);
-        return NULL;
-    }
-
-    bitmap = bdrv_find_dirty_bitmap(bs, name);
-    if (!bitmap) {
-        error_setg(errp, "Dirty bitmap '%s' not found", name);
-        return NULL;
-    }
-
-    if (pbs) {
-        *pbs = bs;
-    }
-
-    return bitmap;
-}
-
 /* New and old BlockDriverState structs for atomic group operations */
 
 typedef struct BlkActionState BlkActionState;
@@ -2171,11 +2124,6 @@ static void block_dirty_bitmap_disable_abort(BlkActionState *common)
     }
 }
 
-static BdrvDirtyBitmap *do_block_dirty_bitmap_merge(
-        const char *node, const char *target,
-        BlockDirtyBitmapMergeSourceList *bitmaps,
-        HBitmap **backup, Error **errp);
-
 static void block_dirty_bitmap_merge_prepare(BlkActionState *common,
                                              Error **errp)
 {
@@ -2189,15 +2137,11 @@ static void block_dirty_bitmap_merge_prepare(BlkActionState *common,
 
     action = common->action->u.block_dirty_bitmap_merge.data;
 
-    state->bitmap = do_block_dirty_bitmap_merge(action->node, action->target,
-                                                action->bitmaps, &state->backup,
-                                                errp);
+    state->bitmap = block_dirty_bitmap_merge(action->node, action->target,
+                                             action->bitmaps, &state->backup,
+                                             errp);
 }
 
-static BdrvDirtyBitmap *do_block_dirty_bitmap_remove(
-        const char *node, const char *name, bool release,
-        BlockDriverState **bitmap_bs, Error **errp);
-
 static void block_dirty_bitmap_remove_prepare(BlkActionState *common,
                                               Error **errp)
 {
@@ -2211,8 +2155,8 @@ static void block_dirty_bitmap_remove_prepare(BlkActionState *common,
 
     action = common->action->u.block_dirty_bitmap_remove.data;
 
-    state->bitmap = do_block_dirty_bitmap_remove(action->node, action->name,
-                                                 false, &state->bs, errp);
+    state->bitmap = block_dirty_bitmap_remove(action->node, action->name,
+                                              false, &state->bs, errp);
     if (state->bitmap) {
         bdrv_dirty_bitmap_skip_store(state->bitmap, true);
         bdrv_dirty_bitmap_set_busy(state->bitmap, true);
@@ -2441,243 +2385,6 @@ void qmp_block_passwd(bool has_device, const char *device,
                "Setting block passwords directly is no longer supported");
 }
 
-void qmp_block_dirty_bitmap_add(const char *node, const char *name,
-                                bool has_granularity, uint32_t granularity,
-                                bool has_persistent, bool persistent,
-                                bool has_disabled, bool disabled,
-                                Error **errp)
-{
-    BlockDriverState *bs;
-    BdrvDirtyBitmap *bitmap;
-    AioContext *aio_context;
-
-    if (!name || name[0] == '\0') {
-        error_setg(errp, "Bitmap name cannot be empty");
-        return;
-    }
-
-    bs = bdrv_lookup_bs(node, node, errp);
-    if (!bs) {
-        return;
-    }
-
-    aio_context = bdrv_get_aio_context(bs);
-    aio_context_acquire(aio_context);
-
-    if (has_granularity) {
-        if (granularity < 512 || !is_power_of_2(granularity)) {
-            error_setg(errp, "Granularity must be power of 2 "
-                             "and at least 512");
-            goto out;
-        }
-    } else {
-        /* Default to cluster size, if available: */
-        granularity = bdrv_get_default_bitmap_granularity(bs);
-    }
-
-    if (!has_persistent) {
-        persistent = false;
-    }
-
-    if (!has_disabled) {
-        disabled = false;
-    }
-
-    if (persistent &&
-        !bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp))
-    {
-        goto out;
-    }
-
-    bitmap = bdrv_create_dirty_bitmap(bs, granularity, name, errp);
-    if (bitmap == NULL) {
-        goto out;
-    }
-
-    if (disabled) {
-        bdrv_disable_dirty_bitmap(bitmap);
-    }
-
-    bdrv_dirty_bitmap_set_persistence(bitmap, persistent);
-
-out:
-    aio_context_release(aio_context);
-}
-
-static BdrvDirtyBitmap *do_block_dirty_bitmap_remove(
-        const char *node, const char *name, bool release,
-        BlockDriverState **bitmap_bs, Error **errp)
-{
-    BlockDriverState *bs;
-    BdrvDirtyBitmap *bitmap;
-    AioContext *aio_context;
-
-    bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
-    if (!bitmap || !bs) {
-        return NULL;
-    }
-
-    aio_context = bdrv_get_aio_context(bs);
-    aio_context_acquire(aio_context);
-
-    if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_BUSY | BDRV_BITMAP_RO,
-                                errp)) {
-        aio_context_release(aio_context);
-        return NULL;
-    }
-
-    if (bdrv_dirty_bitmap_get_persistence(bitmap) &&
-        bdrv_remove_persistent_dirty_bitmap(bs, name, errp) < 0)
-    {
-        aio_context_release(aio_context);
-        return NULL;
-    }
-
-    if (release) {
-        bdrv_release_dirty_bitmap(bitmap);
-    }
-
-    if (bitmap_bs) {
-        *bitmap_bs = bs;
-    }
-
-    aio_context_release(aio_context);
-    return release ? NULL : bitmap;
-}
-
-void qmp_block_dirty_bitmap_remove(const char *node, const char *name,
-                                   Error **errp)
-{
-    do_block_dirty_bitmap_remove(node, name, true, NULL, errp);
-}
-
-/**
- * Completely clear a bitmap, for the purposes of synchronizing a bitmap
- * immediately after a full backup operation.
- */
-void qmp_block_dirty_bitmap_clear(const char *node, const char *name,
-                                  Error **errp)
-{
-    BdrvDirtyBitmap *bitmap;
-    BlockDriverState *bs;
-
-    bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
-    if (!bitmap || !bs) {
-        return;
-    }
-
-    if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, errp)) {
-        return;
-    }
-
-    bdrv_clear_dirty_bitmap(bitmap, NULL);
-}
-
-void qmp_block_dirty_bitmap_enable(const char *node, const char *name,
-                                   Error **errp)
-{
-    BlockDriverState *bs;
-    BdrvDirtyBitmap *bitmap;
-
-    bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
-    if (!bitmap) {
-        return;
-    }
-
-    if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
-        return;
-    }
-
-    bdrv_enable_dirty_bitmap(bitmap);
-}
-
-void qmp_block_dirty_bitmap_disable(const char *node, const char *name,
-                                    Error **errp)
-{
-    BlockDriverState *bs;
-    BdrvDirtyBitmap *bitmap;
-
-    bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
-    if (!bitmap) {
-        return;
-    }
-
-    if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
-        return;
-    }
-
-    bdrv_disable_dirty_bitmap(bitmap);
-}
-
-static BdrvDirtyBitmap *do_block_dirty_bitmap_merge(
-        const char *node, const char *target,
-        BlockDirtyBitmapMergeSourceList *bitmaps,
-        HBitmap **backup, Error **errp)
-{
-    BlockDriverState *bs;
-    BdrvDirtyBitmap *dst, *src, *anon;
-    BlockDirtyBitmapMergeSourceList *lst;
-    Error *local_err = NULL;
-
-    dst = block_dirty_bitmap_lookup(node, target, &bs, errp);
-    if (!dst) {
-        return NULL;
-    }
-
-    anon = bdrv_create_dirty_bitmap(bs, bdrv_dirty_bitmap_granularity(dst),
-                                    NULL, errp);
-    if (!anon) {
-        return NULL;
-    }
-
-    for (lst = bitmaps; lst; lst = lst->next) {
-        switch (lst->value->type) {
-            const char *name, *node;
-        case QTYPE_QSTRING:
-            name = lst->value->u.local;
-            src = bdrv_find_dirty_bitmap(bs, name);
-            if (!src) {
-                error_setg(errp, "Dirty bitmap '%s' not found", name);
-                dst = NULL;
-                goto out;
-            }
-            break;
-        case QTYPE_QDICT:
-            node = lst->value->u.external.node;
-            name = lst->value->u.external.name;
-            src = block_dirty_bitmap_lookup(node, name, NULL, errp);
-            if (!src) {
-                dst = NULL;
-                goto out;
-            }
-            break;
-        default:
-            abort();
-        }
-
-        bdrv_merge_dirty_bitmap(anon, src, NULL, &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
-            dst = NULL;
-            goto out;
-        }
-    }
-
-    /* Merge into dst; dst is unchanged on failure. */
-    bdrv_merge_dirty_bitmap(dst, anon, backup, errp);
-
- out:
-    bdrv_release_dirty_bitmap(anon);
-    return dst;
-}
-
-void qmp_block_dirty_bitmap_merge(const char *node, const char *target,
-                                  BlockDirtyBitmapMergeSourceList *bitmaps,
-                                  Error **errp)
-{
-    do_block_dirty_bitmap_merge(node, target, bitmaps, NULL, errp);
-}
-
 BlockDirtyBitmapSha256 *qmp_x_debug_block_dirty_bitmap_sha256(const char *node,
                                                               const char *name,
                                                               Error **errp)
diff --git a/docs/tools/qemu-img.rst b/docs/tools/qemu-img.rst
index f4ffe528ea..38d464ea3f 100644
--- a/docs/tools/qemu-img.rst
+++ b/docs/tools/qemu-img.rst
@@ -142,30 +142,6 @@ by the used format or see the format descriptions below for details.
   the documentation of the emulator's ``-drive cache=...`` option for allowed
   values.
 
-Parameters to snapshot subcommand:
-
-.. program:: qemu-img-snapshot
-
-.. option:: snapshot
-
-  Is the name of the snapshot to create, apply or delete
-
-.. option:: -a
-
-  Applies a snapshot (revert disk to saved state)
-
-.. option:: -c
-
-  Creates a snapshot
-
-.. option:: -d
-
-  Deletes a snapshot
-
-.. option:: -l
-
-  Lists all snapshots in the given image
-
 Parameters to compare subcommand:
 
 .. program:: qemu-img-compare
@@ -245,6 +221,30 @@ Parameters to dd subcommand:
 
   Sets the number of input blocks to skip
 
+Parameters to snapshot subcommand:
+
+.. program:: qemu-img-snapshot
+
+.. option:: snapshot
+
+  Is the name of the snapshot to create, apply or delete
+
+.. option:: -a
+
+  Applies a snapshot (revert disk to saved state)
+
+.. option:: -c
+
+  Creates a snapshot
+
+.. option:: -d
+
+  Deletes a snapshot
+
+.. option:: -l
+
+  Lists all snapshots in the given image
+
 Command description:
 
 .. program:: qemu-img-commands
@@ -281,6 +281,30 @@ Command description:
   For write tests, by default a buffer filled with zeros is written. This can be
   overridden with a pattern byte specified by *PATTERN*.
 
+.. option:: bitmap (--merge SOURCE | --add | --remove | --clear | --enable | --disable)... [-b SOURCE_FILE [-F SOURCE_FMT]] [-g GRANULARITY] [--object OBJECTDEF] [--image-opts | -f FMT] FILENAME BITMAP
+
+  Perform one or more modifications of the persistent bitmap *BITMAP*
+  in the disk image *FILENAME*.  The various modifications are:
+
+  ``--add`` to create *BITMAP*, enabled to record future edits.
+
+  ``--remove`` to remove *BITMAP*.
+
+  ``--clear`` to clear *BITMAP*.
+
+  ``--enable`` to change *BITMAP* to start recording future edits.
+
+  ``--disable`` to change *BITMAP* to stop recording future edits.
+
+  ``--merge`` to merge the contents of *SOURCE_BITMAP* into *BITMAP*.
+
+  Additional options include ``-g`` which sets a non-default
+  *GRANULARITY* for ``--add``, and ``-b`` and ``-F`` which select an
+  alternative source file for all *SOURCE* bitmaps used by
+  ``--merge``.
+
+  To see what bitmaps are present in an image, use ``qemu-img info``.
+
 .. option:: check [--object OBJECTDEF] [--image-opts] [-q] [-f FMT] [--output=OFMT] [-r [leaks | all]] [-T SRC_CACHE] [-U] FILENAME
 
   Perform a consistency check on the disk image *FILENAME*. The command can
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 5e4f4c348c..791de6a59c 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -568,6 +568,7 @@ struct BlockDriver {
                              uint64_t parent_perm, uint64_t parent_shared,
                              uint64_t *nperm, uint64_t *nshared);
 
+    bool (*bdrv_supports_persistent_dirty_bitmap)(BlockDriverState *bs);
     bool (*bdrv_co_can_store_new_dirty_bitmap)(BlockDriverState *bs,
                                                const char *name,
                                                uint32_t granularity,
@@ -1343,4 +1344,16 @@ int coroutine_fn bdrv_co_create_opts_simple(BlockDriver *drv,
                                             Error **errp);
 extern QemuOptsList bdrv_create_opts_simple;
 
+BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node,
+                                           const char *name,
+                                           BlockDriverState **pbs,
+                                           Error **errp);
+BdrvDirtyBitmap *block_dirty_bitmap_merge(const char *node, const char *target,
+                                          BlockDirtyBitmapMergeSourceList *bms,
+                                          HBitmap **backup, Error **errp);
+BdrvDirtyBitmap *block_dirty_bitmap_remove(const char *node, const char *name,
+                                           bool release,
+                                           BlockDriverState **bitmap_bs,
+                                           Error **errp);
+
 #endif /* BLOCK_INT_H */
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 8a10029418..5a8d52e4de 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -16,6 +16,7 @@ typedef enum BitmapCheckFlags {
 
 #define BDRV_BITMAP_MAX_NAME_SIZE 1023
 
+bool bdrv_supports_persistent_dirty_bitmap(BlockDriverState *bs);
 BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
                                           uint32_t granularity,
                                           const char *name,
diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index 35f832816f..a87d3cb264 100644
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -7,7 +7,7 @@ HXCOMM command structures and help message.
 HXCOMM HXCOMM can be used for comments, discarded from both rST and C
 
 HXCOMM When amending the rST sections, please remember to copy the usage
-HXCOMM over to the per-command sections in qemu-img.texi.
+HXCOMM over to the per-command sections in docs/tools/qemu-img.rst.
 
 DEF("amend", img_amend,
     "amend [--object objectdef] [--image-opts] [-p] [-q] [-f fmt] [-t cache] -o options filename")
@@ -20,6 +20,13 @@ DEF("bench", img_bench,
 SRST
 .. option:: bench [-c COUNT] [-d DEPTH] [-f FMT] [--flush-interval=FLUSH_INTERVAL] [-i AIO] [-n] [--no-drain] [-o OFFSET] [--pattern=PATTERN] [-q] [-s BUFFER_SIZE] [-S STEP_SIZE] [-t CACHE] [-w] [-U] FILENAME
 ERST
+
+DEF("bitmap", img_bitmap,
+    "bitmap (--merge SOURCE | --add | --remove | --clear | --enable | --disable)... [-b source_file [-F source_fmt]] [-g granularity] [--object objectdef] [--image-opts | -f fmt] filename bitmap")
+SRST
+.. option:: bitmap (--merge SOURCE | --add | --remove | --clear | --enable | --disable)... [-b SOURCE_FILE [-F SOURCE_FMT]] [-g GRANULARITY] [--object OBJECTDEF] [--image-opts | -f FMT] FILENAME BITMAP
+ERST
+
 DEF("check", img_check,
     "check [--object objectdef] [--image-opts] [-q] [-f fmt] [--output=ofmt] [-r [leaks | all]] [-T src_cache] [-U] filename")
 SRST
diff --git a/qemu-img.c b/qemu-img.c
index 2a9186139d..2d30682f12 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -28,6 +28,7 @@
 #include "qemu-common.h"
 #include "qemu-version.h"
 #include "qapi/error.h"
+#include "qapi/qapi-commands-block-core.h"
 #include "qapi/qapi-visit-block-core.h"
 #include "qapi/qobject-output-visitor.h"
 #include "qapi/qmp/qjson.h"
@@ -71,6 +72,12 @@ enum {
     OPTION_SHRINK = 266,
     OPTION_SALVAGE = 267,
     OPTION_TARGET_IS_ZERO = 268,
+    OPTION_ADD = 269,
+    OPTION_REMOVE = 270,
+    OPTION_CLEAR = 271,
+    OPTION_ENABLE = 272,
+    OPTION_DISABLE = 273,
+    OPTION_MERGE = 274,
 };
 
 typedef enum OutputFormat {
@@ -108,7 +115,7 @@ static void QEMU_NORETURN unrecognized_option(const char *option)
     error_exit("unrecognized option '%s'", option);
 }
 
-/* Please keep in synch with qemu-img.texi */
+/* Please keep in synch with docs/tools/qemu-img.rst */
 static void QEMU_NORETURN help(void)
 {
     const char *help_msg =
@@ -169,6 +176,14 @@ static void QEMU_NORETURN help(void)
            "  '-n' skips the target volume creation (useful if the volume is created\n"
            "       prior to running qemu-img)\n"
            "\n"
+           "Parameters to bitmap subcommand:\n"
+           "  'bitmap' is the name of the bitmap to manipulate, through one or more\n"
+           "       actions from '--add', '--remove', '--clear', '--enable', '--disable',\n"
+           "       or '--merge source'\n"
+           "  '-g granularity' sets the granularity for '--add' actions\n"
+           "  '-b source' and '-F src_fmt' tell '--merge' actions to find the source\n"
+           "       bitmaps from an alternative file\n"
+           "\n"
            "Parameters to check subcommand:\n"
            "  '-r' tries to repair any inconsistencies that are found during the check.\n"
            "       '-r leaks' repairs only cluster leaks, whereas '-r all' fixes all\n"
@@ -4502,6 +4517,239 @@ out:
     return 0;
 }
 
+enum ImgBitmapAct {
+    BITMAP_ADD,
+    BITMAP_REMOVE,
+    BITMAP_CLEAR,
+    BITMAP_ENABLE,
+    BITMAP_DISABLE,
+    BITMAP_MERGE,
+};
+typedef struct ImgBitmapAction {
+    enum ImgBitmapAct act;
+    const char *src; /* only used for merge */
+    QSIMPLEQ_ENTRY(ImgBitmapAction) next;
+} ImgBitmapAction;
+
+static int img_bitmap(int argc, char **argv)
+{
+    Error *err = NULL;
+    int c, ret = 1;
+    QemuOpts *opts = NULL;
+    const char *fmt = NULL, *src_fmt = NULL, *src_filename = NULL;
+    const char *filename, *bitmap;
+    BlockBackend *blk = NULL, *src = NULL;
+    BlockDriverState *bs = NULL, *src_bs = NULL;
+    bool image_opts = false;
+    int64_t granularity = 0;
+    bool add = false, merge = false;
+    QSIMPLEQ_HEAD(, ImgBitmapAction) actions;
+    ImgBitmapAction *act, *act_next;
+    const char *op;
+
+    QSIMPLEQ_INIT(&actions);
+
+    for (;;) {
+        static const struct option long_options[] = {
+            {"help", no_argument, 0, 'h'},
+            {"object", required_argument, 0, OPTION_OBJECT},
+            {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
+            {"add", no_argument, 0, OPTION_ADD},
+            {"remove", no_argument, 0, OPTION_REMOVE},
+            {"clear", no_argument, 0, OPTION_CLEAR},
+            {"enable", no_argument, 0, OPTION_ENABLE},
+            {"disable", no_argument, 0, OPTION_DISABLE},
+            {"merge", required_argument, 0, OPTION_MERGE},
+            {"granularity", required_argument, 0, 'g'},
+            {"source-file", required_argument, 0, 'b'},
+            {"source-format", required_argument, 0, 'F'},
+            {0, 0, 0, 0}
+        };
+        c = getopt_long(argc, argv, ":b:f:F:g:h", long_options, NULL);
+        if (c == -1) {
+            break;
+        }
+
+        switch (c) {
+        case ':':
+            missing_argument(argv[optind - 1]);
+            break;
+        case '?':
+            unrecognized_option(argv[optind - 1]);
+            break;
+        case 'h':
+            help();
+            break;
+        case 'b':
+            src_filename = optarg;
+            break;
+        case 'f':
+            fmt = optarg;
+            break;
+        case 'F':
+            src_fmt = optarg;
+            break;
+        case 'g':
+            granularity = cvtnum("granularity", optarg);
+            if (granularity < 0) {
+                return 1;
+            }
+            break;
+        case OPTION_ADD:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_ADD;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            add = true;
+            break;
+        case OPTION_REMOVE:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_REMOVE;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            break;
+        case OPTION_CLEAR:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_CLEAR;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            break;
+        case OPTION_ENABLE:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_ENABLE;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            break;
+        case OPTION_DISABLE:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_DISABLE;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            break;
+        case OPTION_MERGE:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_MERGE;
+            act->src = optarg;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            merge = true;
+            break;
+        case OPTION_OBJECT:
+            opts = qemu_opts_parse_noisily(&qemu_object_opts, optarg, true);
+            if (!opts) {
+                goto out;
+            }
+            break;
+        case OPTION_IMAGE_OPTS:
+            image_opts = true;
+            break;
+        }
+    }
+
+    if (qemu_opts_foreach(&qemu_object_opts,
+                          user_creatable_add_opts_foreach,
+                          qemu_img_object_print_help, &error_fatal)) {
+        goto out;
+    }
+
+    if (QSIMPLEQ_EMPTY(&actions)) {
+        error_report("Need at least one of --add, --remove, --clear, "
+                     "--enable, --disable, or --merge");
+        goto out;
+    }
+
+    if (granularity && !add) {
+        error_report("granularity only supported with --add");
+        goto out;
+    }
+    if (src_fmt && !src_filename) {
+        error_report("-F only supported with -b");
+        goto out;
+    }
+    if (src_filename && !merge) {
+        error_report("Merge bitmap source file only supported with "
+                     "--merge");
+        goto out;
+    }
+
+    if (optind != argc - 2) {
+        error_report("Expecting filename and bitmap name");
+        goto out;
+    }
+
+    filename = argv[optind];
+    bitmap = argv[optind + 1];
+
+    blk = img_open(image_opts, filename, fmt, BDRV_O_RDWR, false, false,
+                   false);
+    if (!blk) {
+        goto out;
+    }
+    bs = blk_bs(blk);
+    if (src_filename) {
+        src = img_open(false, src_filename, src_fmt, 0, false, false, false);
+        if (!src) {
+            goto out;
+        }
+        src_bs = blk_bs(src);
+    } else {
+        src_bs = bs;
+    }
+
+    QSIMPLEQ_FOREACH_SAFE(act, &actions, next, act_next) {
+        switch (act->act) {
+        case BITMAP_ADD:
+            qmp_block_dirty_bitmap_add(bs->node_name, bitmap,
+                                       !!granularity, granularity, true, true,
+                                       false, false, &err);
+            op = "add";
+            break;
+        case BITMAP_REMOVE:
+            qmp_block_dirty_bitmap_remove(bs->node_name, bitmap, &err);
+            op = "remove";
+            break;
+        case BITMAP_CLEAR:
+            qmp_block_dirty_bitmap_clear(bs->node_name, bitmap, &err);
+            op = "clear";
+            break;
+        case BITMAP_ENABLE:
+            qmp_block_dirty_bitmap_enable(bs->node_name, bitmap, &err);
+            op = "enable";
+            break;
+        case BITMAP_DISABLE:
+            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);
+            op = "merge";
+            break;
+        }
+        default:
+            g_assert_not_reached();
+        }
+
+        if (err) {
+            error_reportf_err(err, "Operation %s on bitmap %s failed: ",
+                              op, bitmap);
+            goto out;
+        }
+        g_free(act);
+    }
+
+    ret = 0;
+
+ out:
+    blk_unref(src);
+    blk_unref(blk);
+    qemu_opts_del(opts);
+    return ret;
+}
+
 #define C_BS      01
 #define C_COUNT   02
 #define C_IF      04