Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- qemu-storage-daemon: add --pidfile option
- qemu-storage-daemon: CLI error messages include the option name now
- vhost-user-blk export: Misc fixes
- docs: Improvements for qemu-storage-daemon documentation
- parallels: load bitmap extension
- backup-top: Don't crash on post-finalize accesses
- Improve error messages related to node-name options
- iotests improvements

# gpg: Signature made Mon 08 Mar 2021 17:01:41 GMT
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (30 commits)
  blockdev: Clarify error messages pertaining to 'node-name'
  block: Clarify error messages pertaining to 'node-name'
  docs: qsd: Explain --export nbd,name=... default
  MAINTAINERS: update parallels block driver
  iotests: add parallels-read-bitmap test
  iotests.py: add unarchive_sample_image() helper
  parallels: support bitmap extension for read-only mode
  block/parallels: BDRVParallelsState: add cluster_size field
  parallels.txt: fix bitmap L1 table description
  qcow2-bitmap: make bytes_covered_by_bitmap_cluster() public
  block/export: port virtio-blk read/write range check
  block/export: port virtio-blk discard/write zeroes input validation
  block/export: fix vhost-user-blk export sector number calculation
  block/export: use VIRTIO_BLK_SECTOR_BITS
  block/export: fix blk_size double byteswap
  libqtest: add qtest_remove_abrt_handler()
  libqtest: add qtest_kill_qemu()
  libqtest: add qtest_socket_server()
  vhost-user-blk: fix blkcfg->num_queues endianness
  docs: replace insecure /tmp examples in qsd docs
  ...

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

51 files changed, 969 insertions, 175 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index f22d83c178..738786146d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3132,10 +3132,13 @@ F: block/dmg.c
 parallels
 M: Stefan Hajnoczi <stefanha@redhat.com>
 M: Denis V. Lunev <den@openvz.org>
+M: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
 L: qemu-block@nongnu.org
 S: Supported
 F: block/parallels.c
+F: block/parallels-ext.c
 F: docs/interop/parallels.txt
+T: git https://src.openvz.org/scm/~vsementsov/qemu.git parallels
 
 qed
 M: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/block.c b/block.c
index a1f3cecd75..2daff6d29a 100644
--- a/block.c
+++ b/block.c
@@ -1440,7 +1440,7 @@ static void bdrv_assign_node_name(BlockDriverState *bs,
          * Check for empty string or invalid characters, but not if it is
          * generated (generated names use characters not available to the user)
          */
-        error_setg(errp, "Invalid node name");
+        error_setg(errp, "Invalid node-name: '%s'", node_name);
         return;
     }
 
@@ -1453,7 +1453,7 @@ static void bdrv_assign_node_name(BlockDriverState *bs,
 
     /* takes care of avoiding duplicates node names */
     if (bdrv_find_node(node_name)) {
-        error_setg(errp, "Duplicate node name");
+        error_setg(errp, "Duplicate nodes with node-name='%s'", node_name);
         goto out;
     }
 
@@ -5432,7 +5432,7 @@ BlockDriverState *bdrv_lookup_bs(const char *device,
         }
     }
 
-    error_setg(errp, "Cannot find device=%s nor node_name=%s",
+    error_setg(errp, "Cannot find device=\'%s\' nor node-name=\'%s\'",
                      device ? device : "",
                      node_name ? node_name : "");
     return NULL;
@@ -6752,7 +6752,7 @@ BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
     AioContext *aio_context;
 
     if (!to_replace_bs) {
-        error_setg(errp, "Node name '%s' not found", node_name);
+        error_setg(errp, "Failed to find node with node-name='%s'", node_name);
         return NULL;
     }
 
diff --git a/block/backup-top.c b/block/backup-top.c
index d1253e1aa6..589e8b651d 100644
--- a/block/backup-top.c
+++ b/block/backup-top.c
@@ -45,6 +45,12 @@ static coroutine_fn int backup_top_co_preadv(
         BlockDriverState *bs, uint64_t offset, uint64_t bytes,
         QEMUIOVector *qiov, int flags)
 {
+    BDRVBackupTopState *s = bs->opaque;
+
+    if (!s->active) {
+        return -EIO;
+    }
+
     return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags);
 }
 
@@ -54,6 +60,10 @@ static coroutine_fn int backup_top_cbw(BlockDriverState *bs, uint64_t offset,
     BDRVBackupTopState *s = bs->opaque;
     uint64_t off, end;
 
+    if (!s->active) {
+        return -EIO;
+    }
+
     if (flags & BDRV_REQ_WRITE_UNCHANGED) {
         return 0;
     }
diff --git a/block/backup.c b/block/backup.c
index 94e6dcd72e..6cf2f974aa 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -103,6 +103,7 @@ static void backup_abort(Job *job)
 static void backup_clean(Job *job)
 {
     BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
+    block_job_remove_all_bdrv(&s->common);
     bdrv_backup_top_drop(s->backup_top);
 }
 
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 9b9cd71238..a0eaa28785 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -726,6 +726,19 @@ uint64_t bdrv_dirty_bitmap_serialization_align(const BdrvDirtyBitmap *bitmap)
     return hbitmap_serialization_align(bitmap->bitmap);
 }
 
+/* Return the disk size covered by a chunk of serialized bitmap data. */
+uint64_t bdrv_dirty_bitmap_serialization_coverage(int serialized_chunk_size,
+                                                  const BdrvDirtyBitmap *bitmap)
+{
+    uint64_t granularity = bdrv_dirty_bitmap_granularity(bitmap);
+    uint64_t limit = granularity * (serialized_chunk_size << 3);
+
+    assert(QEMU_IS_ALIGNED(limit,
+                           bdrv_dirty_bitmap_serialization_align(bitmap)));
+    return limit;
+}
+
+
 void bdrv_dirty_bitmap_serialize_part(const BdrvDirtyBitmap *bitmap,
                                       uint8_t *buf, uint64_t offset,
                                       uint64_t bytes)
diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
index ab2c4d44c4..cb5d896b7b 100644
--- a/block/export/vhost-user-blk-server.c
+++ b/block/export/vhost-user-blk-server.c
@@ -20,8 +20,17 @@
 #include "sysemu/block-backend.h"
 #include "util/block-helpers.h"
 
+/*
+ * Sector units are 512 bytes regardless of the
+ * virtio_blk_config->blk_size value.
+ */
+#define VIRTIO_BLK_SECTOR_BITS 9
+#define VIRTIO_BLK_SECTOR_SIZE (1ull << VIRTIO_BLK_SECTOR_BITS)
+
 enum {
     VHOST_USER_BLK_NUM_QUEUES_DEFAULT = 1,
+    VHOST_USER_BLK_MAX_DISCARD_SECTORS = 32768,
+    VHOST_USER_BLK_MAX_WRITE_ZEROES_SECTORS = 32768,
 };
 struct virtio_blk_inhdr {
     unsigned char status;
@@ -58,30 +67,102 @@ static void vu_blk_req_complete(VuBlkReq *req)
     free(req);
 }
 
+static bool vu_blk_sect_range_ok(VuBlkExport *vexp, uint64_t sector,
+                                 size_t size)
+{
+    uint64_t nb_sectors = size >> BDRV_SECTOR_BITS;
+    uint64_t total_sectors;
+
+    if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
+        return false;
+    }
+    if ((sector << VIRTIO_BLK_SECTOR_BITS) % vexp->blk_size) {
+        return false;
+    }
+    blk_get_geometry(vexp->export.blk, &total_sectors);
+    if (sector > total_sectors || nb_sectors > total_sectors - sector) {
+        return false;
+    }
+    return true;
+}
+
 static int coroutine_fn
-vu_blk_discard_write_zeroes(BlockBackend *blk, struct iovec *iov,
+vu_blk_discard_write_zeroes(VuBlkExport *vexp, struct iovec *iov,
                             uint32_t iovcnt, uint32_t type)
 {
+    BlockBackend *blk = vexp->export.blk;
     struct virtio_blk_discard_write_zeroes desc;
-    ssize_t size = iov_to_buf(iov, iovcnt, 0, &desc, sizeof(desc));
+    ssize_t size;
+    uint64_t sector;
+    uint32_t num_sectors;
+    uint32_t max_sectors;
+    uint32_t flags;
+    int bytes;
+
+    /* Only one desc is currently supported */
+    if (unlikely(iov_size(iov, iovcnt) > sizeof(desc))) {
+        return VIRTIO_BLK_S_UNSUPP;
+    }
+
+    size = iov_to_buf(iov, iovcnt, 0, &desc, sizeof(desc));
     if (unlikely(size != sizeof(desc))) {
-        error_report("Invalid size %zd, expect %zu", size, sizeof(desc));
-        return -EINVAL;
+        error_report("Invalid size %zd, expected %zu", size, sizeof(desc));
+        return VIRTIO_BLK_S_IOERR;
+    }
+
+    sector = le64_to_cpu(desc.sector);
+    num_sectors = le32_to_cpu(desc.num_sectors);
+    flags = le32_to_cpu(desc.flags);
+    max_sectors = (type == VIRTIO_BLK_T_WRITE_ZEROES) ?
+                  VHOST_USER_BLK_MAX_WRITE_ZEROES_SECTORS :
+                  VHOST_USER_BLK_MAX_DISCARD_SECTORS;
+
+    /* This check ensures that 'bytes' fits in an int */
+    if (unlikely(num_sectors > max_sectors)) {
+        return VIRTIO_BLK_S_IOERR;
     }
 
-    uint64_t range[2] = { le64_to_cpu(desc.sector) << 9,
-                          le32_to_cpu(desc.num_sectors) << 9 };
-    if (type == VIRTIO_BLK_T_DISCARD) {
-        if (blk_co_pdiscard(blk, range[0], range[1]) == 0) {
-            return 0;
+    bytes = num_sectors << VIRTIO_BLK_SECTOR_BITS;
+
+    if (unlikely(!vu_blk_sect_range_ok(vexp, sector, bytes))) {
+        return VIRTIO_BLK_S_IOERR;
+    }
+
+    /*
+     * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for discard
+     * and write zeroes commands if any unknown flag is set.
+     */
+    if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
+        return VIRTIO_BLK_S_UNSUPP;
+    }
+
+    if (type == VIRTIO_BLK_T_WRITE_ZEROES) {
+        int blk_flags = 0;
+
+        if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) {
+            blk_flags |= BDRV_REQ_MAY_UNMAP;
         }
-    } else if (type == VIRTIO_BLK_T_WRITE_ZEROES) {
-        if (blk_co_pwrite_zeroes(blk, range[0], range[1], 0) == 0) {
-            return 0;
+
+        if (blk_co_pwrite_zeroes(blk, sector << VIRTIO_BLK_SECTOR_BITS,
+                                 bytes, blk_flags) == 0) {
+            return VIRTIO_BLK_S_OK;
+        }
+    } else if (type == VIRTIO_BLK_T_DISCARD) {
+        /*
+         * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for
+         * discard commands if the unmap flag is set.
+         */
+        if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
+            return VIRTIO_BLK_S_UNSUPP;
+        }
+
+        if (blk_co_pdiscard(blk, sector << VIRTIO_BLK_SECTOR_BITS,
+                            bytes) == 0) {
+            return VIRTIO_BLK_S_OK;
         }
     }
 
-    return -EINVAL;
+    return VIRTIO_BLK_S_IOERR;
 }
 
 static void coroutine_fn vu_blk_virtio_process_req(void *opaque)
@@ -128,6 +209,8 @@ static void coroutine_fn vu_blk_virtio_process_req(void *opaque)
     switch (type & ~VIRTIO_BLK_T_BARRIER) {
     case VIRTIO_BLK_T_IN:
     case VIRTIO_BLK_T_OUT: {
+        QEMUIOVector qiov;
+        int64_t offset;
         ssize_t ret = 0;
         bool is_write = type & VIRTIO_BLK_T_OUT;
         req->sector_num = le64_to_cpu(req->out.sector);
@@ -137,13 +220,24 @@ static void coroutine_fn vu_blk_virtio_process_req(void *opaque)
             break;
         }
 
-        int64_t offset = req->sector_num * vexp->blk_size;
-        QEMUIOVector qiov;
         if (is_write) {
             qemu_iovec_init_external(&qiov, out_iov, out_num);
-            ret = blk_co_pwritev(blk, offset, qiov.size, &qiov, 0);
         } else {
             qemu_iovec_init_external(&qiov, in_iov, in_num);
+        }
+
+        if (unlikely(!vu_blk_sect_range_ok(vexp,
+                                           req->sector_num,
+                                           qiov.size))) {
+            req->in->status = VIRTIO_BLK_S_IOERR;
+            break;
+        }
+
+        offset = req->sector_num << VIRTIO_BLK_SECTOR_BITS;
+
+        if (is_write) {
+            ret = blk_co_pwritev(blk, offset, qiov.size, &qiov, 0);
+        } else {
             ret = blk_co_preadv(blk, offset, qiov.size, &qiov, 0);
         }
         if (ret >= 0) {
@@ -170,19 +264,13 @@ static void coroutine_fn vu_blk_virtio_process_req(void *opaque)
     }
     case VIRTIO_BLK_T_DISCARD:
     case VIRTIO_BLK_T_WRITE_ZEROES: {
-        int rc;
-
         if (!vexp->writable) {
             req->in->status = VIRTIO_BLK_S_IOERR;
             break;
         }
 
-        rc = vu_blk_discard_write_zeroes(blk, &elem->out_sg[1], out_num, type);
-        if (rc == 0) {
-            req->in->status = VIRTIO_BLK_S_OK;
-        } else {
-            req->in->status = VIRTIO_BLK_S_IOERR;
-        }
+        req->in->status = vu_blk_discard_write_zeroes(vexp, out_iov, out_num,
+                                                      type);
         break;
     }
     default:
@@ -347,17 +435,21 @@ vu_blk_initialize_config(BlockDriverState *bs,
                          uint32_t blk_size,
                          uint16_t num_queues)
 {
-    config->capacity = cpu_to_le64(bdrv_getlength(bs) >> BDRV_SECTOR_BITS);
+    config->capacity =
+        cpu_to_le64(bdrv_getlength(bs) >> VIRTIO_BLK_SECTOR_BITS);
     config->blk_size = cpu_to_le32(blk_size);
     config->size_max = cpu_to_le32(0);
     config->seg_max = cpu_to_le32(128 - 2);
     config->min_io_size = cpu_to_le16(1);
     config->opt_io_size = cpu_to_le32(1);
     config->num_queues = cpu_to_le16(num_queues);
-    config->max_discard_sectors = cpu_to_le32(32768);
+    config->max_discard_sectors =
+        cpu_to_le32(VHOST_USER_BLK_MAX_DISCARD_SECTORS);
     config->max_discard_seg = cpu_to_le32(1);
-    config->discard_sector_alignment = cpu_to_le32(config->blk_size >> 9);
-    config->max_write_zeroes_sectors = cpu_to_le32(32768);
+    config->discard_sector_alignment =
+        cpu_to_le32(blk_size >> VIRTIO_BLK_SECTOR_BITS);
+    config->max_write_zeroes_sectors
+        = cpu_to_le32(VHOST_USER_BLK_MAX_WRITE_ZEROES_SECTORS);
     config->max_write_zeroes_seg = cpu_to_le32(1);
 }
 
@@ -383,7 +475,7 @@ static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
     if (vu_opts->has_logical_block_size) {
         logical_block_size = vu_opts->logical_block_size;
     } else {
-        logical_block_size = BDRV_SECTOR_SIZE;
+        logical_block_size = VIRTIO_BLK_SECTOR_SIZE;
     }
     check_block_size(exp->id, "logical-block-size", logical_block_size,
                      &local_err);
diff --git a/block/meson.build b/block/meson.build
index eeaefe5809..d21990ec95 100644
--- a/block/meson.build
+++ b/block/meson.build
@@ -57,7 +57,8 @@ block_ss.add(when: 'CONFIG_QED', if_true: files(
   'qed-table.c',
   'qed.c',
 ))
-block_ss.add(when: [libxml2, 'CONFIG_PARALLELS'], if_true: files('parallels.c'))
+block_ss.add(when: [libxml2, 'CONFIG_PARALLELS'],
+             if_true: files('parallels.c', 'parallels-ext.c'))
 block_ss.add(when: 'CONFIG_WIN32', if_true: files('file-win32.c', 'win32-aio.c'))
 block_ss.add(when: 'CONFIG_POSIX', if_true: [files('file-posix.c'), coref, iokit])
 block_ss.add(when: libiscsi, if_true: files('iscsi-opts.c'))
diff --git a/block/parallels-ext.c b/block/parallels-ext.c
new file mode 100644
index 0000000000..e0dd0975c6
--- /dev/null
+++ b/block/parallels-ext.c
@@ -0,0 +1,300 @@
+/*
+ * Support of Parallels Format Extension. It's a part of Parallels format
+ * driver.
+ *
+ * Copyright (c) 2021 Virtuozzo International GmbH
+ *
+ * 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 "qapi/error.h"
+#include "block/block_int.h"
+#include "parallels.h"
+#include "crypto/hash.h"
+#include "qemu/uuid.h"
+
+#define PARALLELS_FORMAT_EXTENSION_MAGIC 0xAB234CEF23DCEA87ULL
+
+#define PARALLELS_END_OF_FEATURES_MAGIC 0x0ULL
+#define PARALLELS_DIRTY_BITMAP_FEATURE_MAGIC 0x20385FAE252CB34AULL
+
+typedef struct ParallelsFormatExtensionHeader {
+    uint64_t magic; /* PARALLELS_FORMAT_EXTENSION_MAGIC */
+    uint8_t check_sum[16];
+} QEMU_PACKED ParallelsFormatExtensionHeader;
+
+typedef struct ParallelsFeatureHeader {
+    uint64_t magic;
+    uint64_t flags;
+    uint32_t data_size;
+    uint32_t _unused;
+} QEMU_PACKED ParallelsFeatureHeader;
+
+typedef struct ParallelsDirtyBitmapFeature {
+    uint64_t size;
+    uint8_t id[16];
+    uint32_t granularity;
+    uint32_t l1_size;
+    /* L1 table follows */
+} QEMU_PACKED ParallelsDirtyBitmapFeature;
+
+/* Given L1 table read bitmap data from the image and populate @bitmap */
+static int parallels_load_bitmap_data(BlockDriverState *bs,
+                                      const uint64_t *l1_table,
+                                      uint32_t l1_size,
+                                      BdrvDirtyBitmap *bitmap,
+                                      Error **errp)
+{
+    BDRVParallelsState *s = bs->opaque;
+    int ret = 0;
+    uint64_t offset, limit;
+    uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
+    uint8_t *buf = NULL;
+    uint64_t i, tab_size =
+        DIV_ROUND_UP(bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size),
+                     s->cluster_size);
+
+    if (tab_size != l1_size) {
+        error_setg(errp, "Bitmap table size %" PRIu32 " does not correspond "
+                   "to bitmap size and cluster size. Expected %" PRIu64,
+                   l1_size, tab_size);
+        return -EINVAL;
+    }
+
+    buf = qemu_blockalign(bs, s->cluster_size);
+    limit = bdrv_dirty_bitmap_serialization_coverage(s->cluster_size, bitmap);
+    for (i = 0, offset = 0; i < tab_size; ++i, offset += limit) {
+        uint64_t count = MIN(bm_size - offset, limit);
+        uint64_t entry = l1_table[i];
+
+        if (entry == 0) {
+            /* No need to deserialize zeros because @bitmap is cleared. */
+            continue;
+        }
+
+        if (entry == 1) {
+            bdrv_dirty_bitmap_deserialize_ones(bitmap, offset, count, false);
+        } else {
+            ret = bdrv_pread(bs->file, entry << BDRV_SECTOR_BITS, buf,
+                             s->cluster_size);
+            if (ret < 0) {
+                error_setg_errno(errp, -ret,
+                                 "Failed to read bitmap data cluster");
+                goto finish;
+            }
+            bdrv_dirty_bitmap_deserialize_part(bitmap, buf, offset, count,
+                                               false);
+        }
+    }
+    ret = 0;
+
+    bdrv_dirty_bitmap_deserialize_finish(bitmap);
+
+finish:
+    qemu_vfree(buf);
+
+    return ret;
+}
+
+/*
+ * @data buffer (of @data_size size) is the Dirty bitmaps feature which
+ * consists of ParallelsDirtyBitmapFeature followed by L1 table.
+ */
+static BdrvDirtyBitmap *parallels_load_bitmap(BlockDriverState *bs,
+                                              uint8_t *data,
+                                              size_t data_size,
+                                              Error **errp)
+{
+    int ret;
+    ParallelsDirtyBitmapFeature bf;
+    g_autofree uint64_t *l1_table = NULL;
+    BdrvDirtyBitmap *bitmap;
+    QemuUUID uuid;
+    char uuidstr[UUID_FMT_LEN + 1];
+    int i;
+
+    if (data_size < sizeof(bf)) {
+        error_setg(errp, "Too small Bitmap Feature area in Parallels Format "
+                   "Extension: %zu bytes, expected at least %zu bytes",
+                   data_size, sizeof(bf));
+        return NULL;
+    }
+    memcpy(&bf, data, sizeof(bf));
+    bf.size = le64_to_cpu(bf.size);
+    bf.granularity = le32_to_cpu(bf.granularity) << BDRV_SECTOR_BITS;
+    bf.l1_size = le32_to_cpu(bf.l1_size);
+    data += sizeof(bf);
+    data_size -= sizeof(bf);
+
+    if (bf.size != bs->total_sectors) {
+        error_setg(errp, "Bitmap size (in sectors) %" PRId64 " differs from "
+                   "disk size in sectors %" PRId64, bf.size, bs->total_sectors);
+        return NULL;
+    }
+
+    if (bf.l1_size * sizeof(uint64_t) > data_size) {
+        error_setg(errp, "Bitmaps feature corrupted: l1 table exceeds "
+                   "extension data_size");
+        return NULL;
+    }
+
+    memcpy(&uuid, bf.id, sizeof(uuid));
+    qemu_uuid_unparse(&uuid, uuidstr);
+    bitmap = bdrv_create_dirty_bitmap(bs, bf.granularity, uuidstr, errp);
+    if (!bitmap) {
+        return NULL;
+    }
+
+    l1_table = g_new(uint64_t, bf.l1_size);
+    for (i = 0; i < bf.l1_size; i++, data += sizeof(uint64_t)) {
+        l1_table[i] = ldq_le_p(data);
+    }
+
+    ret = parallels_load_bitmap_data(bs, l1_table, bf.l1_size, bitmap, errp);
+    if (ret < 0) {
+        bdrv_release_dirty_bitmap(bitmap);
+        return NULL;
+    }
+
+    /* We support format extension only for RO parallels images. */
+    assert(!(bs->open_flags & BDRV_O_RDWR));
+    bdrv_dirty_bitmap_set_readonly(bitmap, true);
+
+    return bitmap;
+}
+
+static int parallels_parse_format_extension(BlockDriverState *bs,
+                                            uint8_t *ext_cluster, Error **errp)
+{
+    BDRVParallelsState *s = bs->opaque;
+    int ret;
+    int remaining = s->cluster_size;
+    uint8_t *pos = ext_cluster;
+    ParallelsFormatExtensionHeader eh;
+    g_autofree uint8_t *hash = NULL;
+    size_t hash_len = 0;
+    GSList *bitmaps = NULL, *el;
+
+    memcpy(&eh, pos, sizeof(eh));
+    eh.magic = le64_to_cpu(eh.magic);
+    pos += sizeof(eh);
+    remaining -= sizeof(eh);
+
+    if (eh.magic != PARALLELS_FORMAT_EXTENSION_MAGIC) {
+        error_setg(errp, "Wrong parallels Format Extension magic: 0x%" PRIx64
+                   ", expected: 0x%llx", eh.magic,
+                   PARALLELS_FORMAT_EXTENSION_MAGIC);
+        goto fail;
+    }
+
+    ret = qcrypto_hash_bytes(QCRYPTO_HASH_ALG_MD5, (char *)pos, remaining,
+                             &hash, &hash_len, errp);
+    if (ret < 0) {
+        goto fail;
+    }
+
+    if (hash_len != sizeof(eh.check_sum) ||
+        memcmp(hash, eh.check_sum, sizeof(eh.check_sum)) != 0) {
+        error_setg(errp, "Wrong checksum in Format Extension header. Format "
+                   "extension is corrupted.");
+        goto fail;
+    }
+
+    while (true) {
+        ParallelsFeatureHeader fh;
+        BdrvDirtyBitmap *bitmap;
+
+        if (remaining < sizeof(fh)) {
+            error_setg(errp, "Can not read feature header, as remaining bytes "
+                       "(%d) in Format Extension is less than Feature header "
+                       "size (%zu)", remaining, sizeof(fh));
+            goto fail;
+        }
+
+        memcpy(&fh, pos, sizeof(fh));
+        pos += sizeof(fh);
+        remaining -= sizeof(fh);
+
+        fh.magic = le64_to_cpu(fh.magic);
+        fh.flags = le64_to_cpu(fh.flags);
+        fh.data_size = le32_to_cpu(fh.data_size);
+
+        if (fh.flags) {
+            error_setg(errp, "Flags for extension feature are unsupported");
+            goto fail;
+        }
+
+        if (fh.data_size > remaining) {
+            error_setg(errp, "Feature data_size exceedes Format Extension "
+                       "cluster");
+            goto fail;
+        }
+
+        switch (fh.magic) {
+        case PARALLELS_END_OF_FEATURES_MAGIC:
+            return 0;
+
+        case PARALLELS_DIRTY_BITMAP_FEATURE_MAGIC:
+            bitmap = parallels_load_bitmap(bs, pos, fh.data_size, errp);
+            if (!bitmap) {
+                goto fail;
+            }
+            bitmaps = g_slist_append(bitmaps, bitmap);
+            break;
+
+        default:
+            error_setg(errp, "Unknown feature: 0x%" PRIu64, fh.magic);
+            goto fail;
+        }
+
+        pos = ext_cluster + QEMU_ALIGN_UP(pos + fh.data_size - ext_cluster, 8);
+    }
+
+fail:
+    for (el = bitmaps; el; el = el->next) {
+        bdrv_release_dirty_bitmap(el->data);
+    }
+    g_slist_free(bitmaps);
+
+    return -EINVAL;
+}
+
+int parallels_read_format_extension(BlockDriverState *bs,
+                                    int64_t ext_off, Error **errp)
+{
+    BDRVParallelsState *s = bs->opaque;
+    int ret;
+    uint8_t *ext_cluster = qemu_blockalign(bs, s->cluster_size);
+
+    assert(ext_off > 0);
+
+    ret = bdrv_pread(bs->file, ext_off, ext_cluster, s->cluster_size);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Failed to read Format Extension cluster");
+        goto out;
+    }
+
+    ret = parallels_parse_format_extension(bs, ext_cluster, errp);
+
+out:
+    qemu_vfree(ext_cluster);
+
+    return ret;
+}
diff --git a/block/parallels.c b/block/parallels.c
index 3c22dfdc9d..6ebad2a2bb 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -29,6 +29,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/error-report.h"
 #include "qapi/error.h"
 #include "block/block_int.h"
 #include "block/qdict.h"
@@ -421,7 +422,6 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs,
     int ret;
     uint32_t i;
     bool flush_bat = false;
-    int cluster_size = s->tracks << BDRV_SECTOR_BITS;
 
     size = bdrv_getlength(bs->file->bs);
     if (size < 0) {
@@ -472,7 +472,7 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs,
             high_off = off;
         }
 
-        if (prev_off != 0 && (prev_off + cluster_size) != off) {
+        if (prev_off != 0 && (prev_off + s->cluster_size) != off) {
             res->bfi.fragmented_clusters++;
         }
         prev_off = off;
@@ -487,10 +487,10 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs,
         }
     }
 
-    res->image_end_offset = high_off + cluster_size;
+    res->image_end_offset = high_off + s->cluster_size;
     if (size > res->image_end_offset) {
         int64_t count;
-        count = DIV_ROUND_UP(size - res->image_end_offset, cluster_size);
+        count = DIV_ROUND_UP(size - res->image_end_offset, s->cluster_size);
         fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
                 fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
                 size - res->image_end_offset);
@@ -771,6 +771,7 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
         ret = -EFBIG;
         goto fail;
     }
+    s->cluster_size = s->tracks << BDRV_SECTOR_BITS;
 
     s->bat_size = le32_to_cpu(ph.bat_entries);
     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
@@ -843,6 +844,23 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
         goto fail_options;
     }
 
+    if (ph.ext_off) {
+        if (flags & BDRV_O_RDWR) {
+            /*
+             * It's unsafe to open image RW if there is an extension (as we
+             * don't support it). But parallels driver in QEMU historically
+             * ignores the extension, so print warning and don't care.
+             */
+            warn_report("Format Extension ignored in RW mode");
+        } else {
+            ret = parallels_read_format_extension(
+                    bs, le64_to_cpu(ph.ext_off) << BDRV_SECTOR_BITS, errp);
+            if (ret < 0) {
+                goto fail;
+            }
+        }
+    }
+
     if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_INACTIVE)) {
         s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
         ret = parallels_update_header(bs);
diff --git a/block/parallels.h b/block/parallels.h
index 5aa101cfc8..f22f43f988 100644
--- a/block/parallels.h
+++ b/block/parallels.h
@@ -48,7 +48,8 @@ typedef struct ParallelsHeader {
     uint64_t nb_sectors;
     uint32_t inuse;
     uint32_t data_off;
-    char padding[12];
+    uint32_t flags;
+    uint64_t ext_off;
 } QEMU_PACKED ParallelsHeader;
 
 typedef enum ParallelsPreallocMode {
@@ -79,9 +80,13 @@ typedef struct BDRVParallelsState {
     ParallelsPreallocMode prealloc_mode;
 
     unsigned int tracks;
+    unsigned int cluster_size;
 
     unsigned int off_multiplier;
     Error *migration_blocker;
 } BDRVParallelsState;
 
+int parallels_read_format_extension(BlockDriverState *bs,
+                                    int64_t ext_off, Error **errp);
+
 #endif
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 5eef82fa55..42d81c44cd 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -278,18 +278,6 @@ static int free_bitmap_clusters(BlockDriverState *bs, Qcow2BitmapTable *tb)
     return 0;
 }
 
-/* Return the disk size covered by a single qcow2 cluster of bitmap data. */
-static uint64_t bytes_covered_by_bitmap_cluster(const BDRVQcow2State *s,
-                                                const BdrvDirtyBitmap *bitmap)
-{
-    uint64_t granularity = bdrv_dirty_bitmap_granularity(bitmap);
-    uint64_t limit = granularity * (s->cluster_size << 3);
-
-    assert(QEMU_IS_ALIGNED(limit,
-                           bdrv_dirty_bitmap_serialization_align(bitmap)));
-    return limit;
-}
-
 /* load_bitmap_data
  * @bitmap_table entries must satisfy specification constraints.
  * @bitmap must be cleared */
@@ -312,7 +300,7 @@ static int load_bitmap_data(BlockDriverState *bs,
     }
 
     buf = g_malloc(s->cluster_size);
-    limit = bytes_covered_by_bitmap_cluster(s, bitmap);
+    limit = bdrv_dirty_bitmap_serialization_coverage(s->cluster_size, bitmap);
     for (i = 0, offset = 0; i < tab_size; ++i, offset += limit) {
         uint64_t count = MIN(bm_size - offset, limit);
         uint64_t entry = bitmap_table[i];
@@ -1303,7 +1291,7 @@ static uint64_t *store_bitmap_data(BlockDriverState *bs,
     }
 
     buf = g_malloc(s->cluster_size);
-    limit = bytes_covered_by_bitmap_cluster(s, bitmap);
+    limit = bdrv_dirty_bitmap_serialization_coverage(s->cluster_size, bitmap);
     assert(DIV_ROUND_UP(bm_size, limit) == tb_size);
 
     offset = 0;
diff --git a/blockdev.c b/blockdev.c
index cd438e60e3..7c7ab2b386 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1515,13 +1515,13 @@ static void external_snapshot_prepare(BlkActionState *common,
             s->has_snapshot_node_name ? s->snapshot_node_name : NULL;
 
         if (node_name && !snapshot_node_name) {
-            error_setg(errp, "New overlay node name missing");
+            error_setg(errp, "New overlay node-name missing");
             goto out;
         }
 
         if (snapshot_node_name &&
             bdrv_lookup_bs(snapshot_node_name, snapshot_node_name, NULL)) {
-            error_setg(errp, "New overlay node name already in use");
+            error_setg(errp, "New overlay node-name already in use");
             goto out;
         }
 
@@ -3598,13 +3598,14 @@ void qmp_x_blockdev_reopen(BlockdevOptions *options, Error **errp)
 
     /* Check for the selected node name */
     if (!options->has_node_name) {
-        error_setg(errp, "Node name not specified");
+        error_setg(errp, "node-name not specified");
         goto fail;
     }
 
     bs = bdrv_find_node(options->node_name);
     if (!bs) {
-        error_setg(errp, "Cannot find node named '%s'", options->node_name);
+        error_setg(errp, "Failed to find node with node-name='%s'",
+                   options->node_name);
         goto fail;
     }
 
@@ -3635,7 +3636,7 @@ void qmp_blockdev_del(const char *node_name, Error **errp)
 
     bs = bdrv_find_node(node_name);
     if (!bs) {
-        error_setg(errp, "Cannot find node %s", node_name);
+        error_setg(errp, "Failed to find node with node-name='%s'", node_name);
         return;
     }
     if (bdrv_has_blk(bs)) {
@@ -3758,7 +3759,7 @@ void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread,
 
     bs = bdrv_find_node(node_name);
     if (!bs) {
-        error_setg(errp, "Cannot find node %s", node_name);
+        error_setg(errp, "Failed to find node with node-name='%s'", node_name);
         return;
     }
 
diff --git a/blockjob.c b/blockjob.c
index f2feff051d..ef968017a2 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -318,8 +318,12 @@ BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
     info->status    = job->job.status;
     info->auto_finalize = job->job.auto_finalize;
     info->auto_dismiss  = job->job.auto_dismiss;
-    info->has_error = job->job.ret != 0;
-    info->error     = job->job.ret ? g_strdup(strerror(-job->job.ret)) : NULL;
+    if (job->job.ret) {
+        info->has_error = true;
+        info->error = job->job.err ?
+                        g_strdup(error_get_pretty(job->job.err)) :
+                        g_strdup(strerror(-job->job.ret));
+    }
     return info;
 }
 
@@ -356,7 +360,7 @@ static void block_job_event_completed(Notifier *n, void *opaque)
     }
 
     if (job->job.ret < 0) {
-        msg = strerror(-job->job.ret);
+        msg = error_get_pretty(job->job.err);
     }
 
     qapi_event_send_block_job_completed(job_type(&job->job),
diff --git a/docs/interop/parallels.txt b/docs/interop/parallels.txt
index f15bf35bd1..bb3fadf369 100644
--- a/docs/interop/parallels.txt
+++ b/docs/interop/parallels.txt
@@ -208,21 +208,25 @@ of its data area are:
   28 - 31:    l1_size
               The number of entries in the L1 table of the bitmap.
 
-  variable:   l1_table (8 * l1_size bytes)
-              L1 offset table (in bytes)
+  variable:   L1 offset table (l1_table), size: 8 * l1_size bytes
 
-A dirty bitmap is stored using a one-level structure for the mapping to host
-clusters - an L1 table.
+The dirty bitmap described by this feature extension is stored in a set of
+clusters inside the Parallels image file. The offsets of these clusters are
+saved in the L1 offset table specified by the feature extension. Each L1 table
+entry is a 64 bit integer as described below:
 
-Given an offset in bytes into the bitmap data, the offset in bytes into the
-image file can be obtained as follows:
+Given an offset in bytes into the bitmap data, corresponding L1 entry is
 
-    offset = l1_table[offset / cluster_size] + (offset % cluster_size)
+    l1_table[offset / cluster_size]
 
-If an L1 table entry is 0, the corresponding cluster of the bitmap is assumed
-to be zero.
+If an L1 table entry is 0, all bits in the corresponding cluster of the bitmap
+are assumed to be 0.
 
-If an L1 table entry is 1, the corresponding cluster of the bitmap is assumed
-to have all bits set.
+If an L1 table entry is 1, all bits in the corresponding cluster of the bitmap
+are assumed to be 1.
 
-If an L1 table entry is not 0 or 1, it allocates a cluster from the data area.
+If an L1 table entry is not 0 or 1, it contains the corresponding cluster
+offset (in 512b sectors). Given an offset in bytes into the bitmap data the
+offset in bytes into the image file can be obtained as follows:
+
+    offset = l1_table[offset / cluster_size] * 512 + (offset % cluster_size)
diff --git a/docs/tools/qemu-storage-daemon.rst b/docs/tools/qemu-storage-daemon.rst
index c05b3d3811..086493ebb3 100644
--- a/docs/tools/qemu-storage-daemon.rst
+++ b/docs/tools/qemu-storage-daemon.rst
@@ -69,7 +69,7 @@ Standard options:
   a description of character device properties. A common character device
   definition configures a UNIX domain socket::
 
-  --chardev socket,id=char1,path=/tmp/qmp.sock,server=on,wait=off
+  --chardev socket,id=char1,path=/var/run/qsd-qmp.sock,server=on,wait=off
 
 .. option:: --export [type=]nbd,id=<id>,node-name=<node-name>[,name=<export-name>][,writable=on|off][,bitmap=<name>]
   --export [type=]vhost-user-blk,id=<id>,node-name=<node-name>,addr.type=unix,addr.path=<socket-path>[,writable=on|off][,logical-block-size=<block-size>][,num-queues=<num-queues>]
@@ -80,8 +80,9 @@ Standard options:
   requests for modifying data (the default is off).
 
   The ``nbd`` export type requires ``--nbd-server`` (see below). ``name`` is
-  the NBD export name. ``bitmap`` is the name of a dirty bitmap reachable from
-  the block node, so the NBD client can use NBD_OPT_SET_META_CONTEXT with the
+  the NBD export name (if not specified, it defaults to the given
+  ``node-name``). ``bitmap`` is the name of a dirty bitmap reachable from the
+  block node, so the NBD client can use NBD_OPT_SET_META_CONTEXT with the
   metadata context name "qemu:dirty-bitmap:BITMAP" to inspect the bitmap.
 
   The ``vhost-user-blk`` export type takes a vhost-user socket address on which
@@ -101,14 +102,17 @@ Standard options:
 
 .. option:: --nbd-server addr.type=inet,addr.host=<host>,addr.port=<port>[,tls-creds=<id>][,tls-authz=<id>][,max-connections=<n>]
   --nbd-server addr.type=unix,addr.path=<path>[,tls-creds=<id>][,tls-authz=<id>][,max-connections=<n>]
+  --nbd-server addr.type=fd,addr.str=<fd>[,tls-creds=<id>][,tls-authz=<id>][,max-connections=<n>]
 
   is a server for NBD exports. Both TCP and UNIX domain sockets are supported.
-  TLS encryption can be configured using ``--object`` tls-creds-* and authz-*
-  secrets (see below).
+  A listen socket can be provided via file descriptor passing (see Examples
+  below). TLS encryption can be configured using ``--object`` tls-creds-* and
+  authz-* secrets (see below).
 
-  To configure an NBD server on UNIX domain socket path ``/tmp/nbd.sock``::
+  To configure an NBD server on UNIX domain socket path
+  ``/var/run/qsd-nbd.sock``::
 
-  --nbd-server addr.type=unix,addr.path=/tmp/nbd.sock
+  --nbd-server addr.type=unix,addr.path=/var/run/qsd-nbd.sock
 
 .. option:: --object help
   --object <type>,help
@@ -118,6 +122,20 @@ Standard options:
   List object properties with ``<type>,help``. See the :manpage:`qemu(1)`
   manual page for a description of the object properties.
 
+.. option:: --pidfile PATH
+
+  is the path to a file where the daemon writes its pid. This allows scripts to
+  stop the daemon by sending a signal::
+
+    $ kill -SIGTERM $(<path/to/qsd.pid)
+
+  A file lock is applied to the file so only one instance of the daemon can run
+  with a given pid file path. The daemon unlinks its pid file when terminating.
+
+  The pid file is written after chardevs, exports, and NBD servers have been
+  created but before accepting connections. The daemon has started successfully
+  when the pid file is written and clients may begin connecting.
+
 Examples
 --------
 Launch the daemon with QMP monitor socket ``qmp.sock`` so clients can execute
@@ -127,6 +145,42 @@ QMP commands::
       --chardev socket,path=qmp.sock,server=on,wait=off,id=char1 \
       --monitor chardev=char1
 
+Launch the daemon from Python with a QMP monitor socket using file descriptor
+passing so there is no need to busy wait for the QMP monitor to become
+available::
+
+  #!/usr/bin/env python3
+  import subprocess
+  import socket
+
+  sock_path = '/var/run/qmp.sock'
+
+  with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as listen_sock:
+      listen_sock.bind(sock_path)
+      listen_sock.listen()
+
+      fd = listen_sock.fileno()
+
+      subprocess.Popen(
+          ['qemu-storage-daemon',
+           '--chardev', f'socket,fd={fd},server=on,id=char1',
+           '--monitor', 'chardev=char1'],
+          pass_fds=[fd],
+      )
+
+  # listen_sock was automatically closed when leaving the 'with' statement
+  # body. If the daemon process terminated early then the following connect()
+  # will fail with "Connection refused" because no process has the listen
+  # socket open anymore. Launch errors can be detected this way.
+
+  qmp_sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+  qmp_sock.connect(sock_path)
+  ...QMP interaction...
+
+The same socket spawning approach also works with the ``--nbd-server
+addr.type=fd,addr.str=<fd>`` and ``--export
+type=vhost-user-blk,addr.type=fd,addr.str=<fd>`` options.
+
 Export raw image file ``disk.img`` over NBD UNIX domain socket ``nbd.sock``::
 
   $ qemu-storage-daemon \
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index da4fbf9084..b870a50e6b 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -54,6 +54,9 @@ static void vhost_user_blk_update_config(VirtIODevice *vdev, uint8_t *config)
 {
     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 
+    /* Our num_queues overrides the device backend */
+    virtio_stw_p(vdev, &s->blkcfg.num_queues, s->num_queues);
+
     memcpy(config, &s->blkcfg, sizeof(struct virtio_blk_config));
 }
 
@@ -491,10 +494,6 @@ reconnect:
         goto reconnect;
     }
 
-    if (s->blkcfg.num_queues != s->num_queues) {
-        s->blkcfg.num_queues = s->num_queues;
-    }
-
     return;
 
 virtio_err:
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 36e8da4fc2..f581cf9fd7 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -57,6 +57,8 @@ void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter);
 uint64_t bdrv_dirty_bitmap_serialization_size(const BdrvDirtyBitmap *bitmap,
                                               uint64_t offset, uint64_t bytes);
 uint64_t bdrv_dirty_bitmap_serialization_align(const BdrvDirtyBitmap *bitmap);
+uint64_t bdrv_dirty_bitmap_serialization_coverage(int serialized_chunk_size,
+        const BdrvDirtyBitmap *bitmap);
 void bdrv_dirty_bitmap_serialize_part(const BdrvDirtyBitmap *bitmap,
                                       uint8_t *buf, uint64_t offset,
                                       uint64_t bytes);
diff --git a/storage-daemon/qemu-storage-daemon.c b/storage-daemon/qemu-storage-daemon.c
index 9021a46b3a..23756fc8e5 100644
--- a/storage-daemon/qemu-storage-daemon.c
+++ b/storage-daemon/qemu-storage-daemon.c
@@ -59,6 +59,7 @@
 #include "sysemu/runstate.h"
 #include "trace/control.h"
 
+static const char *pid_file;
 static volatile bool exit_requested = false;
 
 void qemu_system_killed(int signal, pid_t pid)
@@ -115,6 +116,8 @@ static void help(void)
 "                         See the qemu(1) man page for documentation of the\n"
 "                         objects that can be added.\n"
 "\n"
+"  --pidfile <path>       write process ID to a file after startup\n"
+"\n"
 QEMU_HELP_BOTTOM "\n",
     error_get_progname());
 }
@@ -126,6 +129,7 @@ enum {
     OPTION_MONITOR,
     OPTION_NBD_SERVER,
     OPTION_OBJECT,
+    OPTION_PIDFILE,
 };
 
 extern QemuOptsList qemu_chardev_opts;
@@ -152,6 +156,20 @@ static void init_qmp_commands(void)
                          qmp_marshal_qmp_capabilities, QCO_ALLOW_PRECONFIG);
 }
 
+static int getopt_set_loc(int argc, char **argv, const char *optstring,
+                          const struct option *longopts)
+{
+    int c, save_index;
+
+    optarg = NULL;
+    save_index = optind;
+    c = getopt_long(argc, argv, optstring, longopts, NULL);
+    if (optarg) {
+        loc_set_cmdline(argv, save_index, MAX(1, optind - save_index));
+    }
+    return c;
+}
+
 static void process_options(int argc, char *argv[])
 {
     int c;
@@ -164,6 +182,7 @@ static void process_options(int argc, char *argv[])
         {"monitor", required_argument, NULL, OPTION_MONITOR},
         {"nbd-server", required_argument, NULL, OPTION_NBD_SERVER},
         {"object", required_argument, NULL, OPTION_OBJECT},
+        {"pidfile", required_argument, NULL, OPTION_PIDFILE},
         {"trace", required_argument, NULL, 'T'},
         {"version", no_argument, NULL, 'V'},
         {0, 0, 0, 0}
@@ -174,7 +193,7 @@ static void process_options(int argc, char *argv[])
      * they are given on the command lines. This means that things must be
      * defined first before they can be referenced in another option.
      */
-    while ((c = getopt_long(argc, argv, "hT:V", long_options, NULL)) != -1) {
+    while ((c = getopt_set_loc(argc, argv, "-hT:V", long_options)) != -1) {
         switch (c) {
         case '?':
             exit(EXIT_FAILURE);
@@ -275,14 +294,38 @@ static void process_options(int argc, char *argv[])
                 qobject_unref(args);
                 break;
             }
+        case OPTION_PIDFILE:
+            pid_file = optarg;
+            break;
+        case 1:
+            error_report("Unexpected argument");
+            exit(EXIT_FAILURE);
         default:
             g_assert_not_reached();
         }
     }
-    if (optind != argc) {
-        error_report("Unexpected argument: %s", argv[optind]);
+    loc_set_none();
+}
+
+static void pid_file_cleanup(void)
+{
+    unlink(pid_file);
+}
+
+static void pid_file_init(void)
+{
+    Error *err = NULL;
+
+    if (!pid_file) {
+        return;
+    }
+
+    if (!qemu_write_pidfile(pid_file, &err)) {
+        error_reportf_err(err, "cannot create PID file: ");
         exit(EXIT_FAILURE);
     }
+
+    atexit(pid_file_cleanup);
 }
 
 int main(int argc, char *argv[])
@@ -312,6 +355,13 @@ int main(int argc, char *argv[])
     qemu_init_main_loop(&error_fatal);
     process_options(argc, argv);
 
+    /*
+     * Write the pid file after creating chardevs, exports, and NBD servers but
+     * before accepting connections. This ordering is documented. Do not change
+     * it.
+     */
+    pid_file_init();
+
     while (!exit_requested) {
         main_loop_wait(false);
     }
diff --git a/tests/qemu-iotests/030 b/tests/qemu-iotests/030
index 12aa9ed37e..5fb65b4bef 100755
--- a/tests/qemu-iotests/030
+++ b/tests/qemu-iotests/030
@@ -153,7 +153,7 @@ class TestSingleDrive(iotests.QMPTestCase):
     def test_device_not_found(self):
         result = self.vm.qmp('block-stream', device='nonexistent')
         self.assert_qmp(result, 'error/desc',
-            'Cannot find device=nonexistent nor node_name=nonexistent')
+            'Cannot find device=\'nonexistent\' nor node-name=\'nonexistent\'')
 
     def test_job_id_missing(self):
         result = self.vm.qmp('block-stream', device='mid')
@@ -507,7 +507,7 @@ class TestParallelOps(iotests.QMPTestCase):
         # Error: the base node does not exist
         result = self.vm.qmp('block-stream', device='node4', base_node='none', job_id='stream')
         self.assert_qmp(result, 'error/desc',
-            'Cannot find device= nor node_name=none')
+            'Cannot find device=\'\' nor node-name=\'none\'')
 
         # Error: the base node is not a backing file of the top node
         result = self.vm.qmp('block-stream', device='node4', base_node='node6', job_id='stream')
diff --git a/tests/qemu-iotests/040 b/tests/qemu-iotests/040
index 7ebc9ed825..336ff7c4f2 100755
--- a/tests/qemu-iotests/040
+++ b/tests/qemu-iotests/040
@@ -175,13 +175,13 @@ class TestSingleDrive(ImageCommitTestCase):
         self.assert_no_active_block_jobs()
         result = self.vm.qmp('block-commit', device='drive0', top_node='badfile', base_node='base')
         self.assert_qmp(result, 'error/class', 'GenericError')
-        self.assert_qmp(result, 'error/desc', "Cannot find device= nor node_name=badfile")
+        self.assert_qmp(result, 'error/desc', "Cannot find device='' nor node-name='badfile'")
 
     def test_base_node_invalid(self):
         self.assert_no_active_block_jobs()
         result = self.vm.qmp('block-commit', device='drive0', top_node='mid', base_node='badfile')
         self.assert_qmp(result, 'error/class', 'GenericError')
-        self.assert_qmp(result, 'error/desc', "Cannot find device= nor node_name=badfile")
+        self.assert_qmp(result, 'error/desc', "Cannot find device='' nor node-name='badfile'")
 
     def test_top_path_and_node(self):
         self.assert_no_active_block_jobs()
diff --git a/tests/qemu-iotests/051.pc.out b/tests/qemu-iotests/051.pc.out
index f707471fb0..f570610f64 100644
--- a/tests/qemu-iotests/051.pc.out
+++ b/tests/qemu-iotests/051.pc.out
@@ -61,13 +61,13 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) quit
 
 Testing: -drive file=TEST_DIR/t.qcow2,node-name=123foo
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=123foo: Invalid node name
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=123foo: Invalid node-name: '123foo'
 
 Testing: -drive file=TEST_DIR/t.qcow2,node-name=_foo
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=_foo: Invalid node name
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=_foo: Invalid node-name: '_foo'
 
 Testing: -drive file=TEST_DIR/t.qcow2,node-name=foo#12
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=foo#12: Invalid node name
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=foo#12: Invalid node-name: 'foo#12'
 
 
 === Device without drive ===
diff --git a/tests/qemu-iotests/081.out b/tests/qemu-iotests/081.out
index 1974262fac..615c083549 100644
--- a/tests/qemu-iotests/081.out
+++ b/tests/qemu-iotests/081.out
@@ -140,7 +140,7 @@ Testing:
 QMP_VERSION
 {"return": {}}
 {"error": {"class": "GenericError", "desc": "blkverify=on can only be set if there are exactly two files and vote-threshold is 2"}}
-{"error": {"class": "GenericError", "desc": "Cannot find device=drive0-quorum nor node_name=drive0-quorum"}}
+{"error": {"class": "GenericError", "desc": "Cannot find device='drive0-quorum' nor node-name='drive0-quorum'"}}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}}
 
diff --git a/tests/qemu-iotests/085.out b/tests/qemu-iotests/085.out
index 32a193f2c2..1d4c565b6d 100644
--- a/tests/qemu-iotests/085.out
+++ b/tests/qemu-iotests/085.out
@@ -24,7 +24,7 @@ Formatting 'TEST_DIR/1-snapshot-v0.qcow2', fmt=qcow2 cluster_size=65536 extended
 { 'execute': 'blockdev-snapshot-sync',
                          'arguments': { 'snapshot-file':'TEST_DIR/1-snapshot-v0.IMGFMT',
                                      'format': 'IMGFMT' } }
-{"error": {"class": "GenericError", "desc": "Cannot find device= nor node_name="}}
+{"error": {"class": "GenericError", "desc": "Cannot find device='' nor node-name=''"}}
 
 === Invalid command - missing snapshot-file ===
 
@@ -222,10 +222,10 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 backing_file=TEST_DIR/
 { 'execute': 'blockdev-snapshot',
                       'arguments': { 'node': 'virtio0',
                                      'overlay':'snap_14' } }
-{"error": {"class": "GenericError", "desc": "Cannot find device=snap_14 nor node_name=snap_14"}}
+{"error": {"class": "GenericError", "desc": "Cannot find device='snap_14' nor node-name='snap_14'"}}
 { 'execute': 'blockdev-snapshot',
                      'arguments': { 'node':'nodevice',
                                     'overlay':'snap_13' }
                    }
-{"error": {"class": "GenericError", "desc": "Cannot find device=nodevice nor node_name=nodevice"}}
+{"error": {"class": "GenericError", "desc": "Cannot find device='nodevice' nor node-name='nodevice'"}}
 *** done
diff --git a/tests/qemu-iotests/087 b/tests/qemu-iotests/087
index edd43f1a28..d8e0e384cd 100755
--- a/tests/qemu-iotests/087
+++ b/tests/qemu-iotests/087
@@ -143,9 +143,7 @@ run_qemu <<EOF
   "arguments": {
       "qom-type": "secret",
       "id": "sec0",
-      "props": {
-          "data": "123456"
-      }
+      "data": "123456"
   }
 }
 { "execute": "blockdev-add",
@@ -176,9 +174,7 @@ run_qemu <<EOF
   "arguments": {
       "qom-type": "secret",
       "id": "sec0",
-      "props": {
-          "data": "123456"
-      }
+      "data": "123456"
   }
 }
 { "execute": "blockdev-add",
diff --git a/tests/qemu-iotests/087.out b/tests/qemu-iotests/087.out
index b61ba638af..e1c23a6983 100644
--- a/tests/qemu-iotests/087.out
+++ b/tests/qemu-iotests/087.out
@@ -17,7 +17,7 @@ Testing: -drive driver=IMGFMT,id=disk,node-name=test-node,file=TEST_DIR/t.IMGFMT
 QMP_VERSION
 {"return": {}}
 {"error": {"class": "GenericError", "desc": "node-name=disk is conflicting with a device id"}}
-{"error": {"class": "GenericError", "desc": "Duplicate node name"}}
+{"error": {"class": "GenericError", "desc": "Duplicate nodes with node-name='test-node'"}}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}}
 
diff --git a/tests/qemu-iotests/184 b/tests/qemu-iotests/184
index 513d167098..e4cbcd8634 100755
--- a/tests/qemu-iotests/184
+++ b/tests/qemu-iotests/184
@@ -67,10 +67,8 @@ run_qemu <<EOF
   "arguments": {
     "qom-type": "throttle-group",
     "id": "group0",
-    "props": {
-      "limits" : {
-        "iops-total": 1000
-      }
+    "limits" : {
+      "iops-total": 1000
     }
   }
 }
@@ -96,10 +94,8 @@ run_qemu <<EOF
   "arguments": {
     "qom-type": "throttle-group",
     "id": "group0",
-    "props" : {
-      "limits": {
-          "iops-total": 1000
-      }
+    "limits": {
+        "iops-total": 1000
     }
   }
 }
@@ -136,10 +132,8 @@ run_qemu <<EOF
   "arguments": {
     "qom-type": "throttle-group",
     "id": "group0",
-    "props" : {
-      "limits": {
-          "iops-total": 1000
-      }
+    "limits": {
+        "iops-total": 1000
     }
   }
 }
diff --git a/tests/qemu-iotests/206.out b/tests/qemu-iotests/206.out
index 5dd589d14e..b68c443867 100644
--- a/tests/qemu-iotests/206.out
+++ b/tests/qemu-iotests/206.out
@@ -155,7 +155,7 @@ Format specific information:
 
 {"execute": "blockdev-create", "arguments": {"job-id": "job0", "options": {"driver": "qcow2", "file": "this doesn't exist", "size": 33554432}}}
 {"return": {}}
-Job failed: Cannot find device=this doesn't exist nor node_name=this doesn't exist
+Job failed: Cannot find device='this doesn't exist' nor node-name='this doesn't exist'
 {"execute": "job-dismiss", "arguments": {"id": "job0"}}
 {"return": {}}
 
diff --git a/tests/qemu-iotests/210.out b/tests/qemu-iotests/210.out
index 2e9fc596eb..55c0844370 100644
--- a/tests/qemu-iotests/210.out
+++ b/tests/qemu-iotests/210.out
@@ -108,7 +108,7 @@ Format specific information:
 
 {"execute": "blockdev-create", "arguments": {"job-id": "job0", "options": {"driver": "luks", "file": "this doesn't exist", "size": 67108864}}}
 {"return": {}}
-Job failed: Cannot find device=this doesn't exist nor node_name=this doesn't exist
+Job failed: Cannot find device='this doesn't exist' nor node-name='this doesn't exist'
 {"execute": "job-dismiss", "arguments": {"id": "job0"}}
 {"return": {}}
 
diff --git a/tests/qemu-iotests/211.out b/tests/qemu-iotests/211.out
index b83384deea..3bc092a8a8 100644
--- a/tests/qemu-iotests/211.out
+++ b/tests/qemu-iotests/211.out
@@ -62,7 +62,7 @@ cluster_size: 1048576
 
 {"execute": "blockdev-create", "arguments": {"job-id": "job0", "options": {"driver": "vdi", "file": "this doesn't exist", "size": 33554432}}}
 {"return": {}}
-Job failed: Cannot find device=this doesn't exist nor node_name=this doesn't exist
+Job failed: Cannot find device='this doesn't exist' nor node-name='this doesn't exist'
 {"execute": "job-dismiss", "arguments": {"id": "job0"}}
 {"return": {}}
 
diff --git a/tests/qemu-iotests/212.out b/tests/qemu-iotests/212.out
index 1538d679be..8102033488 100644
--- a/tests/qemu-iotests/212.out
+++ b/tests/qemu-iotests/212.out
@@ -52,7 +52,7 @@ virtual size: 32 MiB (33554432 bytes)
 
 {"execute": "blockdev-create", "arguments": {"job-id": "job0", "options": {"driver": "parallels", "file": "this doesn't exist", "size": 33554432}}}
 {"return": {}}
-Job failed: Cannot find device=this doesn't exist nor node_name=this doesn't exist
+Job failed: Cannot find device='this doesn't exist' nor node-name='this doesn't exist'
 {"execute": "job-dismiss", "arguments": {"id": "job0"}}
 {"return": {}}
 
diff --git a/tests/qemu-iotests/213.out b/tests/qemu-iotests/213.out
index be4ae85180..3cdce4d790 100644
--- a/tests/qemu-iotests/213.out
+++ b/tests/qemu-iotests/213.out
@@ -55,7 +55,7 @@ cluster_size: 268435456
 
 {"execute": "blockdev-create", "arguments": {"job-id": "job0", "options": {"driver": "vhdx", "file": "this doesn't exist", "size": 33554432}}}
 {"return": {}}
-Job failed: Cannot find device=this doesn't exist nor node_name=this doesn't exist
+Job failed: Cannot find device='this doesn't exist' nor node-name='this doesn't exist'
 {"execute": "job-dismiss", "arguments": {"id": "job0"}}
 {"return": {}}
 
diff --git a/tests/qemu-iotests/218 b/tests/qemu-iotests/218
index ae7c4fb187..325d8244fb 100755
--- a/tests/qemu-iotests/218
+++ b/tests/qemu-iotests/218
@@ -152,7 +152,7 @@ with iotests.VM() as vm, \
     vm.launch()
 
     ret = vm.qmp('object-add', qom_type='throttle-group', id='tg',
-                 props={'x-bps-read': 4096})
+                 limits={'bps-read': 4096})
     assert ret['return'] == {}
 
     ret = vm.qmp('blockdev-add',
diff --git a/tests/qemu-iotests/223.out b/tests/qemu-iotests/223.out
index bbc85289e3..083b62d053 100644
--- a/tests/qemu-iotests/223.out
+++ b/tests/qemu-iotests/223.out
@@ -53,7 +53,7 @@ exports available: 0
 {"return": {}}
 {"execute":"nbd-server-add",
   "arguments":{"device":"nosuch"}}
-{"error": {"class": "GenericError", "desc": "Cannot find device=nosuch nor node_name=nosuch"}}
+{"error": {"class": "GenericError", "desc": "Cannot find device='nosuch' nor node-name='nosuch'"}}
 {"execute":"nbd-server-add",
   "arguments":{"device":"n"}}
 {"error": {"class": "GenericError", "desc": "Block export id 'n' is already in use"}}
@@ -154,7 +154,7 @@ exports available: 0
 {"return": {}}
 {"execute":"nbd-server-add",
   "arguments":{"device":"nosuch"}}
-{"error": {"class": "GenericError", "desc": "Cannot find device=nosuch nor node_name=nosuch"}}
+{"error": {"class": "GenericError", "desc": "Cannot find device='nosuch' nor node-name='nosuch'"}}
 {"execute":"nbd-server-add",
   "arguments":{"device":"n"}}
 {"error": {"class": "GenericError", "desc": "Block export id 'n' is already in use"}}
diff --git a/tests/qemu-iotests/235 b/tests/qemu-iotests/235
index 20d16dbf38..8aed45f9a7 100755
--- a/tests/qemu-iotests/235
+++ b/tests/qemu-iotests/235
@@ -57,7 +57,7 @@ vm.add_args('-drive', 'id=src,file=' + disk)
 vm.launch()
 
 log(vm.qmp('object-add', qom_type='throttle-group', id='tg0',
-           props={ 'x-bps-total': size }))
+           limits={'bps-total': size}))
 
 log(vm.qmp('blockdev-add',
            **{ 'node-name': 'target',
diff --git a/tests/qemu-iotests/237.out b/tests/qemu-iotests/237.out
index a8c800bfad..aa94986803 100644
--- a/tests/qemu-iotests/237.out
+++ b/tests/qemu-iotests/237.out
@@ -85,7 +85,7 @@ Format specific information:
 
 {"execute": "blockdev-create", "arguments": {"job-id": "job0", "options": {"driver": "vmdk", "file": "this doesn't exist", "size": 33554432}}}
 {"return": {}}
-Job failed: Cannot find device=this doesn't exist nor node_name=this doesn't exist
+Job failed: Cannot find device='this doesn't exist' nor node-name='this doesn't exist'
 {"execute": "job-dismiss", "arguments": {"id": "job0"}}
 {"return": {}}
 
diff --git a/tests/qemu-iotests/245 b/tests/qemu-iotests/245
index cfdeb902be..11104b9208 100755
--- a/tests/qemu-iotests/245
+++ b/tests/qemu-iotests/245
@@ -140,8 +140,8 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.reopen(opts, {'file': 'hd0-file'})
 
         # We cannot change any of these
-        self.reopen(opts, {'node-name': 'not-found'}, "Cannot find node named 'not-found'")
-        self.reopen(opts, {'node-name': ''}, "Cannot find node named ''")
+        self.reopen(opts, {'node-name': 'not-found'}, "Failed to find node with node-name='not-found'")
+        self.reopen(opts, {'node-name': ''}, "Failed to find node with node-name=''")
         self.reopen(opts, {'node-name': None}, "Invalid parameter type for 'node-name', expected: string")
         self.reopen(opts, {'driver': 'raw'}, "Cannot change the option 'driver'")
         self.reopen(opts, {'driver': ''}, "Invalid parameter ''")
@@ -158,7 +158,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
 
         # node-name is optional in BlockdevOptions, but x-blockdev-reopen needs it
         del opts['node-name']
-        self.reopen(opts, {}, "Node name not specified")
+        self.reopen(opts, {}, "node-name not specified")
 
         # Check that nothing has changed
         self.check_node_graph(original_graph)
@@ -187,8 +187,8 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.reopen(opts, {'backing': backing_node_name})
 
         # We can't use a non-existing or empty (non-NULL) node as the backing image
-        self.reopen(opts, {'backing': 'not-found'}, "Cannot find device= nor node_name=not-found")
-        self.reopen(opts, {'backing': ''}, "Cannot find device= nor node_name=")
+        self.reopen(opts, {'backing': 'not-found'}, "Cannot find device=\'\' nor node-name=\'not-found\'")
+        self.reopen(opts, {'backing': ''}, "Cannot find device=\'\' nor node-name=\'\'")
 
         # We can reopen the image just fine if we specify the backing options
         opts['backing'] = {'driver': iotests.imgfmt,
@@ -644,12 +644,12 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         ###### throttle ######
         ######################
         opts = { 'qom-type': 'throttle-group', 'id': 'group0',
-                 'props': { 'limits': { 'iops-total': 1000 } } }
+                 'limits': { 'iops-total': 1000 } }
         result = self.vm.qmp('object-add', conv_keys = False, **opts)
         self.assert_qmp(result, 'return', {})
 
         opts = { 'qom-type': 'throttle-group', 'id': 'group1',
-                 'props': { 'limits': { 'iops-total': 2000 } } }
+                 'limits': { 'iops-total': 2000 } }
         result = self.vm.qmp('object-add', conv_keys = False, **opts)
         self.assert_qmp(result, 'return', {})
 
diff --git a/tests/qemu-iotests/249.out b/tests/qemu-iotests/249.out
index 92ec81db03..d2bf9be85e 100644
--- a/tests/qemu-iotests/249.out
+++ b/tests/qemu-iotests/249.out
@@ -18,7 +18,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.
                      'filter-node-name': '1234'}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "job0"}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "null", "id": "job0"}}
-{"error": {"class": "GenericError", "desc": "Invalid node name"}}
+{"error": {"class": "GenericError", "desc": "Invalid node-name: '1234'"}}
 
 === Send a write command to a drive opened in read-only mode (2)
 
diff --git a/tests/qemu-iotests/258 b/tests/qemu-iotests/258
index 9a2d33ae5e..a6618208a8 100755
--- a/tests/qemu-iotests/258
+++ b/tests/qemu-iotests/258
@@ -103,9 +103,9 @@ def test_concurrent_finish(write_to_stream_node):
         vm.qmp_log('object-add',
                    qom_type='throttle-group',
                    id='tg',
-                   props={
-                       'x-iops-write': 1,
-                       'x-iops-write-max': 1
+                   limits={
+                       'iops-write': 1,
+                       'iops-write-max': 1
                    })
 
         vm.qmp_log('blockdev-add',
diff --git a/tests/qemu-iotests/258.out b/tests/qemu-iotests/258.out
index ce6e9ba3e5..c3a003d3e3 100644
--- a/tests/qemu-iotests/258.out
+++ b/tests/qemu-iotests/258.out
@@ -2,7 +2,7 @@ Running tests:
 
 === Commit and stream finish concurrently (letting stream write) ===
 
-{"execute": "object-add", "arguments": {"id": "tg", "props": {"x-iops-write": 1, "x-iops-write-max": 1}, "qom-type": "throttle-group"}}
+{"execute": "object-add", "arguments": {"id": "tg", "limits": {"iops-write": 1, "iops-write-max": 1}, "qom-type": "throttle-group"}}
 {"return": {}}
 {"execute": "blockdev-add", "arguments": {"backing": {"backing": {"backing": {"backing": {"driver": "raw", "file": {"driver": "file", "filename": "TEST_DIR/PID-node0.img"}, "node-name": "node0"}, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-node1.img"}, "node-name": "node1"}, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-node2.img"}, "node-name": "node2"}, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-node3.img"}, "node-name": "node3"}, "driver": "IMGFMT", "file": {"driver": "throttle", "file": {"driver": "file", "filename": "TEST_DIR/PID-node4.img"}, "throttle-group": "tg"}, "node-name": "node4"}}
 {"return": {}}
@@ -18,7 +18,7 @@ Running tests:
 
 === Commit and stream finish concurrently (letting commit write) ===
 
-{"execute": "object-add", "arguments": {"id": "tg", "props": {"x-iops-write": 1, "x-iops-write-max": 1}, "qom-type": "throttle-group"}}
+{"execute": "object-add", "arguments": {"id": "tg", "limits": {"iops-write": 1, "iops-write-max": 1}, "qom-type": "throttle-group"}}
 {"return": {}}
 {"execute": "blockdev-add", "arguments": {"backing": {"backing": {"backing": {"backing": {"driver": "raw", "file": {"driver": "throttle", "file": {"driver": "file", "filename": "TEST_DIR/PID-node0.img"}, "throttle-group": "tg"}, "node-name": "node0"}, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-node1.img"}, "node-name": "node1"}, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-node2.img"}, "node-name": "node2"}, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-node3.img"}, "node-name": "node3"}, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-node4.img"}, "node-name": "node4"}}
 {"return": {}}
diff --git a/tests/qemu-iotests/283 b/tests/qemu-iotests/283
index 79643e375b..010c22f0a2 100755
--- a/tests/qemu-iotests/283
+++ b/tests/qemu-iotests/283
@@ -97,3 +97,56 @@ vm.qmp_log('blockdev-add', **{
 vm.qmp_log('blockdev-backup', sync='full', device='source', target='target')
 
 vm.shutdown()
+
+
+print('\n=== backup-top should be gone after job-finalize ===\n')
+
+# Check that the backup-top node is gone after job-finalize.
+#
+# During finalization, the node becomes inactive and can no longer
+# function.  If it is still present, new parents might be attached, and
+# there would be no meaningful way to handle their I/O requests.
+
+vm = iotests.VM()
+vm.launch()
+
+vm.qmp_log('blockdev-add', **{
+    'node-name': 'source',
+    'driver': 'null-co',
+})
+
+vm.qmp_log('blockdev-add', **{
+    'node-name': 'target',
+    'driver': 'null-co',
+})
+
+vm.qmp_log('blockdev-backup',
+           job_id='backup',
+           device='source',
+           target='target',
+           sync='full',
+           filter_node_name='backup-filter',
+           auto_finalize=False,
+           auto_dismiss=False)
+
+vm.event_wait('BLOCK_JOB_PENDING', 5.0)
+
+# The backup-top filter should still be present prior to finalization
+assert vm.node_info('backup-filter') is not None
+
+vm.qmp_log('job-finalize', id='backup')
+vm.event_wait('BLOCK_JOB_COMPLETED', 5.0)
+
+# The filter should be gone now.  Check that by trying to access it
+# with qemu-io (which will most likely crash qemu if it is still
+# there.).
+vm.qmp_log('human-monitor-command',
+           command_line='qemu-io backup-filter "write 0 1M"')
+
+# (Also, do an explicit check.)
+assert vm.node_info('backup-filter') is None
+
+vm.qmp_log('job-dismiss', id='backup')
+vm.event_wait('JOB_STATUS_CHANGE', 5.0, {'data': {'status': 'null'}})
+
+vm.shutdown()
diff --git a/tests/qemu-iotests/283.out b/tests/qemu-iotests/283.out
index d8cff22cc1..37c35058ae 100644
--- a/tests/qemu-iotests/283.out
+++ b/tests/qemu-iotests/283.out
@@ -6,3 +6,18 @@
 {"return": {}}
 {"execute": "blockdev-backup", "arguments": {"device": "source", "sync": "full", "target": "target"}}
 {"error": {"class": "GenericError", "desc": "Cannot set permissions for backup-top filter: Conflicts with use by other as 'image', which uses 'write' on base"}}
+
+=== backup-top should be gone after job-finalize ===
+
+{"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "source"}}
+{"return": {}}
+{"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "target"}}
+{"return": {}}
+{"execute": "blockdev-backup", "arguments": {"auto-dismiss": false, "auto-finalize": false, "device": "source", "filter-node-name": "backup-filter", "job-id": "backup", "sync": "full", "target": "target"}}
+{"return": {}}
+{"execute": "job-finalize", "arguments": {"id": "backup"}}
+{"return": {}}
+{"execute": "human-monitor-command", "arguments": {"command-line": "qemu-io backup-filter \"write 0 1M\""}}
+{"return": "Error: Cannot find device='' nor node-name='backup-filter'\r\n"}
+{"execute": "job-dismiss", "arguments": {"id": "backup"}}
+{"return": {}}
diff --git a/tests/qemu-iotests/295 b/tests/qemu-iotests/295
index 01a6c0b31f..270ad3999f 100755
--- a/tests/qemu-iotests/295
+++ b/tests/qemu-iotests/295
@@ -43,7 +43,7 @@ class Secret:
 
     def to_qmp_object(self):
         return { "qom_type" : "secret", "id": self.id(),
-                 "props": { "data": self.secret() } }
+                 "data": self.secret() }
 
 ################################################################################
 class EncryptionSetupTestCase(iotests.QMPTestCase):
diff --git a/tests/qemu-iotests/296 b/tests/qemu-iotests/296
index 0bc3c6c7d7..7c65e987a1 100755
--- a/tests/qemu-iotests/296
+++ b/tests/qemu-iotests/296
@@ -43,7 +43,7 @@ class Secret:
 
     def to_qmp_object(self):
         return { "qom_type" : "secret", "id": self.id(),
-                 "props": { "data": self.secret() } }
+                 "data": self.secret() }
 
 ################################################################################
 
diff --git a/tests/qemu-iotests/300 b/tests/qemu-iotests/300
index 63036f6a6e..b475a92c47 100755
--- a/tests/qemu-iotests/300
+++ b/tests/qemu-iotests/300
@@ -22,7 +22,7 @@
 import os
 import random
 import re
-from typing import Dict, List, Optional, Union
+from typing import Dict, List, Optional
 
 import iotests
 
@@ -30,7 +30,7 @@ import iotests
 # pylint: disable=wrong-import-order
 import qemu
 
-BlockBitmapMapping = List[Dict[str, Union[str, List[Dict[str, str]]]]]
+BlockBitmapMapping = List[Dict[str, object]]
 
 mig_sock = os.path.join(iotests.sock_dir, 'mig_sock')
 
@@ -189,8 +189,8 @@ class TestAliasMigration(TestDirtyBitmapMigration):
         # Check for error message on the destination
         if self.src_node_name != self.dst_node_name:
             self.verify_dest_error(f"Cannot find "
-                                   f"device={self.src_node_name} nor "
-                                   f"node_name={self.src_node_name}")
+                                   f"device='{self.src_node_name}' nor "
+                                   f"node-name='{self.src_node_name}'")
         else:
             self.verify_dest_error(None)
 
@@ -602,7 +602,8 @@ class TestCrossAliasMigration(TestDirtyBitmapMigration):
 
 class TestAliasTransformMigration(TestDirtyBitmapMigration):
     """
-    Tests the 'transform' option which modifies bitmap persistence on migration.
+    Tests the 'transform' option which modifies bitmap persistence on
+    migration.
     """
 
     src_node_name = 'node-a'
@@ -674,7 +675,8 @@ class TestAliasTransformMigration(TestDirtyBitmapMigration):
         bitmaps = self.vm_b.query_bitmaps()
 
         for node in bitmaps:
-            bitmaps[node] = sorted(((bmap['name'], bmap['persistent']) for bmap in bitmaps[node]))
+            bitmaps[node] = sorted(((bmap['name'], bmap['persistent'])
+                                    for bmap in bitmaps[node]))
 
         self.assertEqual(bitmaps,
                          {'node-a': [('bmap-a', True), ('bmap-b', False)],
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 4e758308f2..90d0b62523 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -17,6 +17,7 @@
 #
 
 import atexit
+import bz2
 from collections import OrderedDict
 import faulthandler
 import io
@@ -24,6 +25,7 @@ import json
 import logging
 import os
 import re
+import shutil
 import signal
 import struct
 import subprocess
@@ -96,6 +98,14 @@ luks_default_secret_object = 'secret,id=keysec0,data=' + \
                              os.environ.get('IMGKEYSECRET', '')
 luks_default_key_secret_opt = 'key-secret=keysec0'
 
+sample_img_dir = os.environ['SAMPLE_IMG_DIR']
+
+
+def unarchive_sample_image(sample, fname):
+    sample_fname = os.path.join(sample_img_dir, sample + '.bz2')
+    with bz2.open(sample_fname) as f_in, open(fname, 'wb') as f_out:
+        shutil.copyfileobj(f_in, f_out)
+
 
 def qemu_tool_pipe_and_status(tool: str, args: Sequence[str],
                               connect_stderr: bool = True) -> Tuple[str, int]:
diff --git a/tests/qemu-iotests/sample_images/parallels-with-bitmap.bz2 b/tests/qemu-iotests/sample_images/parallels-with-bitmap.bz2
new file mode 100644
index 0000000000..54892fd4d0
--- /dev/null
+++ b/tests/qemu-iotests/sample_images/parallels-with-bitmap.bz2
diff --git a/tests/qemu-iotests/sample_images/parallels-with-bitmap.sh b/tests/qemu-iotests/sample_images/parallels-with-bitmap.sh
new file mode 100755
index 0000000000..30615aa6bd
--- /dev/null
+++ b/tests/qemu-iotests/sample_images/parallels-with-bitmap.sh
@@ -0,0 +1,51 @@
+#!/bin/bash
+#
+# Test parallels load bitmap
+#
+# Copyright (c) 2021 Virtuozzo International GmbH.
+#
+# 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/>.
+#
+
+CT=parallels-with-bitmap-ct
+DIR=$PWD/parallels-with-bitmap-dir
+IMG=$DIR/root.hds
+XML=$DIR/DiskDescriptor.xml
+TARGET=parallels-with-bitmap.bz2
+
+rm -rf $DIR
+
+prlctl create $CT --vmtype ct
+prlctl set $CT --device-add hdd --image $DIR --recreate --size 2G
+
+# cleanup the image
+qemu-img create -f parallels $IMG 64G
+
+# create bitmap
+prlctl backup $CT
+
+prlctl set $CT --device-del hdd1
+prlctl destroy $CT
+
+dev=$(ploop mount $XML | sed -n 's/^Adding delta dev=\(\/dev\/ploop[0-9]\+\).*/\1/p')
+dd if=/dev/zero of=$dev bs=64K seek=5 count=2 oflag=direct
+dd if=/dev/zero of=$dev bs=64K seek=30 count=1 oflag=direct
+dd if=/dev/zero of=$dev bs=64K seek=10 count=3 oflag=direct
+ploop umount $XML  # bitmap name will be in the output
+
+bzip2 -z $IMG
+
+mv $IMG.bz2 $TARGET
+
+rm -rf $DIR
diff --git a/tests/qemu-iotests/tests/parallels-read-bitmap b/tests/qemu-iotests/tests/parallels-read-bitmap
new file mode 100755
index 0000000000..af6b9c5db3
--- /dev/null
+++ b/tests/qemu-iotests/tests/parallels-read-bitmap
@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+#
+# Test parallels load bitmap
+#
+# Copyright (c) 2021 Virtuozzo International GmbH.
+#
+# 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/>.
+#
+
+import json
+import iotests
+from iotests import qemu_nbd_popen, qemu_img_pipe, log, file_path
+
+iotests.script_initialize(supported_fmts=['parallels'])
+
+nbd_sock = file_path('nbd-sock', base_dir=iotests.sock_dir)
+disk = iotests.file_path('disk')
+bitmap = 'e4f2eed0-37fe-4539-b50b-85d2e7fd235f'
+nbd_opts = f'driver=nbd,server.type=unix,server.path={nbd_sock}' \
+        f',x-dirty-bitmap=qemu:dirty-bitmap:{bitmap}'
+
+
+iotests.unarchive_sample_image('parallels-with-bitmap', disk)
+
+
+with qemu_nbd_popen('--read-only', f'--socket={nbd_sock}',
+                    f'--bitmap={bitmap}', '-f', iotests.imgfmt, disk):
+    out = qemu_img_pipe('map', '--output=json', '--image-opts', nbd_opts)
+    chunks = json.loads(out)
+    cluster = 64 * 1024
+
+    log('dirty clusters (cluster size is 64K):')
+    for c in chunks:
+        assert c['start'] % cluster == 0
+        assert c['length'] % cluster == 0
+        if c['data']:
+            continue
+
+        a = c['start'] // cluster
+        b = (c['start'] + c['length']) // cluster
+        if b - a > 1:
+            log(f'{a}-{b-1}')
+        else:
+            log(a)
diff --git a/tests/qemu-iotests/tests/parallels-read-bitmap.out b/tests/qemu-iotests/tests/parallels-read-bitmap.out
new file mode 100644
index 0000000000..e8f6bc9e96
--- /dev/null
+++ b/tests/qemu-iotests/tests/parallels-read-bitmap.out
@@ -0,0 +1,6 @@
+Start NBD server
+dirty clusters (cluster size is 64K):
+5-6
+10-12
+30
+Kill NBD server
diff --git a/tests/qtest/libqos/libqtest.h b/tests/qtest/libqos/libqtest.h
index 724f65aa94..a68dcd79d4 100644
--- a/tests/qtest/libqos/libqtest.h
+++ b/tests/qtest/libqos/libqtest.h
@@ -75,6 +75,17 @@ QTestState *qtest_init_without_qmp_handshake(const char *extra_args);
 QTestState *qtest_init_with_serial(const char *extra_args, int *sock_fd);
 
 /**
+ * qtest_kill_qemu:
+ * @s: #QTestState instance to operate on.
+ *
+ * Kill the QEMU process and wait for it to terminate. It is safe to call this
+ * function multiple times. Normally qtest_quit() is used instead because it
+ * also frees QTestState. Use qtest_kill_qemu() when you just want to kill QEMU
+ * and qtest_quit() will be called later.
+ */
+void qtest_kill_qemu(QTestState *s);
+
+/**
  * qtest_quit:
  * @s: #QTestState instance to operate on.
  *
@@ -133,6 +144,14 @@ void qtest_qmp_send_raw(QTestState *s, const char *fmt, ...)
     GCC_FMT_ATTR(2, 3);
 
 /**
+ * qtest_socket_server:
+ * @socket_path: the UNIX domain socket path
+ *
+ * Create and return a listen socket file descriptor, or abort on failure.
+ */
+int qtest_socket_server(const char *socket_path);
+
+/**
  * qtest_vqmp_fds:
  * @s: #QTestState instance to operate on.
  * @fds: array of file descriptors
@@ -630,9 +649,27 @@ void qtest_add_data_func_full(const char *str, void *data,
         g_free(path); \
     } while (0)
 
+/**
+ * qtest_add_abrt_handler:
+ * @fn: Handler function
+ * @data: Argument that is passed to the handler
+ *
+ * Add a handler function that is invoked on SIGABRT. This can be used to
+ * terminate processes and perform other cleanup. The handler can be removed
+ * with qtest_remove_abrt_handler().
+ */
 void qtest_add_abrt_handler(GHookFunc fn, const void *data);
 
 /**
+ * qtest_remove_abrt_handler:
+ * @data: Argument previously passed to qtest_add_abrt_handler()
+ *
+ * Remove an abrt handler that was previously added with
+ * qtest_add_abrt_handler().
+ */
+void qtest_remove_abrt_handler(void *data);
+
+/**
  * qtest_qmp_assert_success:
  * @qts: QTestState instance to operate on
  * @fmt: QMP message to send to qemu, formatted like
diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c
index fd043b0570..71e359efcd 100644
--- a/tests/qtest/libqtest.c
+++ b/tests/qtest/libqtest.c
@@ -81,24 +81,8 @@ static void qtest_client_set_rx_handler(QTestState *s, QTestRecvFn recv);
 
 static int init_socket(const char *socket_path)
 {
-    struct sockaddr_un addr;
-    int sock;
-    int ret;
-
-    sock = socket(PF_UNIX, SOCK_STREAM, 0);
-    g_assert_cmpint(sock, !=, -1);
-
-    addr.sun_family = AF_UNIX;
-    snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", socket_path);
+    int sock = qtest_socket_server(socket_path);
     qemu_set_cloexec(sock);
-
-    do {
-        ret = bind(sock, (struct sockaddr *)&addr, sizeof(addr));
-    } while (ret == -1 && errno == EINTR);
-    g_assert_cmpint(ret, !=, -1);
-    ret = listen(sock, 1);
-    g_assert_cmpint(ret, !=, -1);
-
     return sock;
 }
 
@@ -149,7 +133,7 @@ void qtest_set_expected_status(QTestState *s, int status)
     s->expected_status = status;
 }
 
-static void kill_qemu(QTestState *s)
+void qtest_kill_qemu(QTestState *s)
 {
     pid_t pid = s->qemu_pid;
     int wstatus;
@@ -159,6 +143,7 @@ static void kill_qemu(QTestState *s)
         kill(pid, SIGTERM);
         TFR(pid = waitpid(s->qemu_pid, &s->wstatus, 0));
         assert(pid == s->qemu_pid);
+        s->qemu_pid = -1;
     }
 
     /*
@@ -185,7 +170,7 @@ static void kill_qemu(QTestState *s)
 
 static void kill_qemu_hook_func(void *s)
 {
-    kill_qemu(s);
+    qtest_kill_qemu(s);
 }
 
 static void sigabrt_handler(int signo)
@@ -211,15 +196,30 @@ static void cleanup_sigabrt_handler(void)
     sigaction(SIGABRT, &sigact_old, NULL);
 }
 
+static bool hook_list_is_empty(GHookList *hook_list)
+{
+    GHook *hook = g_hook_first_valid(hook_list, TRUE);
+
+    if (!hook) {
+        return false;
+    }
+
+    g_hook_unref(hook_list, hook);
+    return true;
+}
+
 void qtest_add_abrt_handler(GHookFunc fn, const void *data)
 {
     GHook *hook;
 
-    /* Only install SIGABRT handler once */
     if (!abrt_hooks.is_setup) {
         g_hook_list_init(&abrt_hooks, sizeof(GHook));
     }
-    setup_sigabrt_handler();
+
+    /* Only install SIGABRT handler once */
+    if (hook_list_is_empty(&abrt_hooks)) {
+        setup_sigabrt_handler();
+    }
 
     hook = g_hook_alloc(&abrt_hooks);
     hook->func = fn;
@@ -228,6 +228,17 @@ void qtest_add_abrt_handler(GHookFunc fn, const void *data)
     g_hook_prepend(&abrt_hooks, hook);
 }
 
+void qtest_remove_abrt_handler(void *data)
+{
+    GHook *hook = g_hook_find_data(&abrt_hooks, TRUE, data);
+    g_hook_destroy_link(&abrt_hooks, hook);
+
+    /* Uninstall SIGABRT handler on last instance */
+    if (hook_list_is_empty(&abrt_hooks)) {
+        cleanup_sigabrt_handler();
+    }
+}
+
 static const char *qtest_qemu_binary(void)
 {
     const char *qemu_bin;
@@ -384,12 +395,9 @@ QTestState *qtest_init_with_serial(const char *extra_args, int *sock_fd)
 
 void qtest_quit(QTestState *s)
 {
-    g_hook_destroy_link(&abrt_hooks, g_hook_find_data(&abrt_hooks, TRUE, s));
-
-    /* Uninstall SIGABRT handler on last instance */
-    cleanup_sigabrt_handler();
+    qtest_remove_abrt_handler(s);
 
-    kill_qemu(s);
+    qtest_kill_qemu(s);
     close(s->fd);
     close(s->qmp_fd);
     g_string_free(s->rx, true);
@@ -638,6 +646,28 @@ QDict *qtest_qmp_receive_dict(QTestState *s)
     return qmp_fd_receive(s->qmp_fd);
 }
 
+int qtest_socket_server(const char *socket_path)
+{
+    struct sockaddr_un addr;
+    int sock;
+    int ret;
+
+    sock = socket(PF_UNIX, SOCK_STREAM, 0);
+    g_assert_cmpint(sock, !=, -1);
+
+    addr.sun_family = AF_UNIX;
+    snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", socket_path);
+
+    do {
+        ret = bind(sock, (struct sockaddr *)&addr, sizeof(addr));
+    } while (ret == -1 && errno == EINTR);
+    g_assert_cmpint(ret, !=, -1);
+    ret = listen(sock, 1);
+    g_assert_cmpint(ret, !=, -1);
+
+    return sock;
+}
+
 /**
  * Allow users to send a message without waiting for the reply,
  * in the case that they choose to discard all replies up until