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

Block patches for 2.3

# gpg: Signature made Tue Mar 10 13:03:17 2015 GMT using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (73 commits)
  MAINTAINERS: Add jcody as blockjobs, block devices maintainer
  iotests: add O_DIRECT alignment probing test
  block/raw-posix: fix launching with failed disks
  MAINTAINERS: Add jsnow as IDE maintainer
  sheepdog: Fix misleading error messages in sd_snapshot_create()
  Add testcase for scsi-hd devices without drive property
  scsi-hd: fix property unset case
  block/vdi: Add locking for parallel requests
  iotests: Drop vpc from 004's and 104's format list
  iotests: Remove 006
  iotests: Fix 051's reference output
  virtio-blk: Remove the stale FIXME comment
  tests: Check QVIRTIO_F_ANY_LAYOUT flag in virtio-blk test
  libqos: Solve bug in interrupt checking when using MSIX in virtio-pci.c
  sheepdog: fix confused return values
  qtest/ahci: add fragmented dma test
  qtest/ahci: Add PIO and LBA48 tests
  qtest/ahci: Add DMA test variants
  libqos/ahci: add ahci command helpers
  qtest/ahci: Add a macro bootup routine
  ...

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

30 files changed, 517 insertions, 169 deletions

diff --git a/tests/qemu-iotests/004 b/tests/qemu-iotests/004
index 651072e..2ad77ed 100755
--- a/tests/qemu-iotests/004
+++ b/tests/qemu-iotests/004
@@ -38,7 +38,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.rc
 . ./common.filter
 
-_supported_fmt generic
+_supported_fmt raw qcow qcow2 qed vdi vmdk vhdx
 _supported_proto generic
 _supported_os Linux
 
diff --git a/tests/qemu-iotests/006.out b/tests/qemu-iotests/006.out
deleted file mode 100644
index d135841..0000000
--- a/tests/qemu-iotests/006.out
+++ /dev/null
@@ -1,6 +0,0 @@
-QA output created by 006
-
-creating 128GB image
-qemu-img: The image size is too large for file format 'vpc'
-Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=137438953472
-*** done
diff --git a/tests/qemu-iotests/007 b/tests/qemu-iotests/007
index fe1a743..7b5aff5 100755
--- a/tests/qemu-iotests/007
+++ b/tests/qemu-iotests/007
@@ -43,6 +43,9 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto generic
 _supported_os Linux
+# refcount_bits must be at least 4 so we can create ten internal snapshots
+# (1 bit supports none, 2 bits support two, 4 bits support 14)
+_unsupported_imgopts 'refcount_bits=\(1\|2\)[^0-9]'
 
 echo
 echo "creating image"
diff --git a/tests/qemu-iotests/015 b/tests/qemu-iotests/015
index 099d757..6f26095 100755
--- a/tests/qemu-iotests/015
+++ b/tests/qemu-iotests/015
@@ -43,6 +43,8 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto generic
 _supported_os Linux
+# Internal snapshots are (currently) impossible with refcount_bits=1
+_unsupported_imgopts 'refcount_bits=1[^0-9]'
 
 echo
 echo "creating image"
diff --git a/tests/qemu-iotests/026 b/tests/qemu-iotests/026
index df2884b..0fc3244 100755
--- a/tests/qemu-iotests/026
+++ b/tests/qemu-iotests/026
@@ -46,6 +46,13 @@ _supported_proto file
 _supported_os Linux
 _default_cache_mode "writethrough"
 _supported_cache_modes "writethrough" "none"
+# The refcount table tests expect a certain minimum width for refcount entries
+# (so that the refcount table actually needs to grow); that minimum is 16 bits,
+# being the default refcount entry width.
+# 32 and 64 bits do not work either, however, due to different leaked cluster
+# count on error.
+# Thus, the only remaining option is refcount_bits=16.
+_unsupported_imgopts 'refcount_bits=\([^1]\|.\([^6]\|$\)\)'
 
 echo "Errors while writing 128 kB"
 echo
diff --git a/tests/qemu-iotests/026.out b/tests/qemu-iotests/026.out
index 524f7ee..5e964fb 100644
--- a/tests/qemu-iotests/026.out
+++ b/tests/qemu-iotests/026.out
@@ -140,19 +140,13 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 5; imm: off; once: on; write
-Failed to flush the L2 table cache: Input/output error
 write failed: Input/output error
-
-127 leaked clusters were found on the image.
-This means waste of disk space, but no harm to data.
+No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 5; imm: off; once: on; write -b
-Failed to flush the L2 table cache: Input/output error
 write failed: Input/output error
-
-127 leaked clusters were found on the image.
-This means waste of disk space, but no harm to data.
+No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 5; imm: off; once: off; write
@@ -174,19 +168,13 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 28; imm: off; once: on; write
-Failed to flush the L2 table cache: No space left on device
 write failed: No space left on device
-
-127 leaked clusters were found on the image.
-This means waste of disk space, but no harm to data.
+No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 28; imm: off; once: on; write -b
-Failed to flush the L2 table cache: No space left on device
 write failed: No space left on device
-
-127 leaked clusters were found on the image.
-This means waste of disk space, but no harm to data.
+No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 28; imm: off; once: off; write
@@ -356,13 +344,11 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 5; imm: off; once: on; write
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 5; imm: off; once: on; write -b
-Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -382,13 +368,11 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 28; imm: off; once: on; write
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 28; imm: off; once: on; write -b
-Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
diff --git a/tests/qemu-iotests/029 b/tests/qemu-iotests/029
index fa46ace..b9cd826 100755
--- a/tests/qemu-iotests/029
+++ b/tests/qemu-iotests/029
@@ -44,6 +44,8 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto generic
 _supported_os Linux
+# Internal snapshots are (currently) impossible with refcount_bits=1
+_unsupported_imgopts 'refcount_bits=1[^0-9]'
 
 offset_size=24
 offset_l1_size=36
diff --git a/tests/qemu-iotests/049.out b/tests/qemu-iotests/049.out
index b6311b0..765afdd 100644
--- a/tests/qemu-iotests/049.out
+++ b/tests/qemu-iotests/049.out
@@ -4,90 +4,90 @@ QA output created by 049
 == 1. Traditional size parameter ==
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1024
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1024b
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1k
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1K
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1048576 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1048576 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1073741824 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1073741824 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1T
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1099511627776 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1099511627776 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1024.0
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1024.0b
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1.5k
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1.5K
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1.5M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1572864 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1572864 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1.5G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1610612736 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1610612736 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 1.5T
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1649267441664 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1649267441664 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 == 2. Specifying size via -o ==
 
 qemu-img create -f qcow2 -o size=1024 TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1024b TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1k TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1K TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1M TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1048576 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1048576 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1G TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1073741824 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1073741824 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1T TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1099511627776 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1099511627776 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1024.0 TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1024.0b TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1.5k TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1.5K TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1536 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1.5M TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1572864 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1572864 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1.5G TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1610612736 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1610612736 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o size=1.5T TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1649267441664 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1649267441664 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 == 3. Invalid sizes ==
 
@@ -97,7 +97,7 @@ qemu-img: Image size must be less than 8 EiB!
 qemu-img create -f qcow2 -o size=-1024 TEST_DIR/t.qcow2
 qemu-img: qcow2 doesn't support shrinking images yet
 qemu-img: TEST_DIR/t.qcow2: Could not resize image: Operation not supported
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=-1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=-1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 -- -1k
 qemu-img: Image size must be less than 8 EiB!
@@ -105,14 +105,14 @@ qemu-img: Image size must be less than 8 EiB!
 qemu-img create -f qcow2 -o size=-1k TEST_DIR/t.qcow2
 qemu-img: qcow2 doesn't support shrinking images yet
 qemu-img: TEST_DIR/t.qcow2: Could not resize image: Operation not supported
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=-1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=-1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 -- 1kilobyte
 qemu-img: Invalid image size specified! You may use k, M, G, T, P or E suffixes for
 qemu-img: kilobytes, megabytes, gigabytes, terabytes, petabytes and exabytes.
 
 qemu-img create -f qcow2 -o size=1kilobyte TEST_DIR/t.qcow2
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1024 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 -- foobar
 qemu-img: Invalid image size specified! You may use k, M, G, T, P or E suffixes for
@@ -125,84 +125,84 @@ qemu-img: TEST_DIR/t.qcow2: Invalid options for file format 'qcow2'
 == Check correct interpretation of suffixes for cluster size ==
 
 qemu-img create -f qcow2 -o cluster_size=1024 TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o cluster_size=1024b TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o cluster_size=1k TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o cluster_size=1K TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o cluster_size=1M TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1048576 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1048576 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o cluster_size=1024.0 TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o cluster_size=1024.0b TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=1024 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o cluster_size=0.5k TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=512 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=512 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o cluster_size=0.5K TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=512 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=512 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o cluster_size=0.5M TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=524288 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=524288 lazy_refcounts=off refcount_bits=16
 
 == Check compat level option ==
 
 qemu-img create -f qcow2 -o compat=0.10 TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='0.10' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='0.10' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o compat=1.1 TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='1.1' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='1.1' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o compat=0.42 TEST_DIR/t.qcow2 64M
 qemu-img: TEST_DIR/t.qcow2: Invalid compatibility level: '0.42'
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='0.42' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='0.42' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o compat=foobar TEST_DIR/t.qcow2 64M
 qemu-img: TEST_DIR/t.qcow2: Invalid compatibility level: 'foobar'
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='foobar' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='foobar' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 == Check preallocation option ==
 
 qemu-img create -f qcow2 -o preallocation=off TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=65536 preallocation='off' lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=65536 preallocation='off' lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o preallocation=metadata TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=65536 preallocation='metadata' lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=65536 preallocation='metadata' lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o preallocation=1234 TEST_DIR/t.qcow2 64M
 qemu-img: TEST_DIR/t.qcow2: invalid parameter value: 1234
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=65536 preallocation='1234' lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=65536 preallocation='1234' lazy_refcounts=off refcount_bits=16
 
 == Check encryption option ==
 
 qemu-img create -f qcow2 -o encryption=off TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o encryption=on TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=on cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 encryption=on cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 == Check lazy_refcounts option (only with v3) ==
 
 qemu-img create -f qcow2 -o compat=1.1,lazy_refcounts=off TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='1.1' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='1.1' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o compat=1.1,lazy_refcounts=on TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='1.1' encryption=off cluster_size=65536 lazy_refcounts=on
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='1.1' encryption=off cluster_size=65536 lazy_refcounts=on refcount_bits=16
 
 qemu-img create -f qcow2 -o compat=0.10,lazy_refcounts=off TEST_DIR/t.qcow2 64M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='0.10' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='0.10' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o compat=0.10,lazy_refcounts=on TEST_DIR/t.qcow2 64M
 qemu-img: TEST_DIR/t.qcow2: Lazy refcounts only supported with compatibility level 1.1 and above (use compat=1.1 or greater)
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='0.10' encryption=off cluster_size=65536 lazy_refcounts=on
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat='0.10' encryption=off cluster_size=65536 lazy_refcounts=on refcount_bits=16
 
 *** done
diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051
index 27138a2..0360f37 100755
--- a/tests/qemu-iotests/051
+++ b/tests/qemu-iotests/051
@@ -41,6 +41,9 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto file
 _supported_os Linux
+# A compat=0.10 image is created in this test which does not support anything
+# other than refcount_bits=16
+_unsupported_imgopts 'refcount_bits=\([^1]\|.\([^6]\|$\)\)'
 
 function do_run_qemu()
 {
@@ -96,6 +99,12 @@ run_qemu -drive file="$TEST_IMG",driver=raw,format=qcow2
 run_qemu -drive file="$TEST_IMG",driver=qcow2,format=qcow2
 
 echo
+echo === Device without drive ===
+echo
+
+run_qemu -device virtio-scsi-pci -device scsi-hd
+
+echo
 echo === Overriding backing file ===
 echo
 
diff --git a/tests/qemu-iotests/051.out b/tests/qemu-iotests/051.out
index bf52bf0..09895e6 100644
--- a/tests/qemu-iotests/051.out
+++ b/tests/qemu-iotests/051.out
@@ -47,6 +47,14 @@ Testing: -drive file=TEST_DIR/t.qcow2,driver=qcow2,format=qcow2
 QEMU_PROG: -drive file=TEST_DIR/t.qcow2,driver=qcow2,format=qcow2: Cannot specify both 'driver' and 'format'
 
 
+=== Device without drive ===
+
+Testing: -device virtio-scsi-pci -device scsi-hd
+QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) QEMU_PROG: -device scsi-hd: drive property not set
+QEMU_PROG: -device scsi-hd: Device 'scsi-hd' could not be initialized
+
+
 === Overriding backing file ===
 
 Testing: -drive file=TEST_DIR/t.qcow2,driver=qcow2,backing.file.filename=TEST_DIR/t.qcow2.orig -nodefaults
@@ -115,8 +123,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
 Testing: -drive if=ide
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) QEMU_PROG: Device needs media, but drive is empty
-QEMU_PROG: Device initialization failed.
-QEMU_PROG: Initialization of device ide-hd failed
+QEMU_PROG: Initialization of device ide-hd failed: Device initialization failed.
 
 Testing: -drive if=virtio
 QEMU X.Y.Z monitor - type 'help' for more information
@@ -127,8 +134,7 @@ QEMU_PROG: -drive if=virtio: Device 'virtio-blk-pci' could not be initialized
 Testing: -drive if=scsi
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) QEMU_PROG: -drive if=scsi: Device needs media, but drive is empty
-QEMU_PROG: Device initialization failed.
-QEMU_PROG: Initialization of device lsi53c895a failed
+QEMU_PROG: Initialization of device lsi53c895a failed: Device initialization failed.
 
 Testing: -drive if=none,id=disk -device ide-cd,drive=disk
 QEMU X.Y.Z monitor - type 'help' for more information
@@ -178,8 +184,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
 Testing: -drive file=TEST_DIR/t.qcow2,if=ide,readonly=on
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) QEMU_PROG: Can't use a read-only drive
-QEMU_PROG: Device initialization failed.
-QEMU_PROG: Initialization of device ide-hd failed
+QEMU_PROG: Initialization of device ide-hd failed: Device initialization failed.
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=virtio,readonly=on
 QEMU X.Y.Z monitor - type 'help' for more information
diff --git a/tests/qemu-iotests/058 b/tests/qemu-iotests/058
index a60b34b..f2bdd0b 100755
--- a/tests/qemu-iotests/058
+++ b/tests/qemu-iotests/058
@@ -89,6 +89,8 @@ _supported_fmt qcow2
 _supported_proto file
 _supported_os Linux
 _require_command QEMU_NBD
+# Internal snapshots are (currently) impossible with refcount_bits=1
+_unsupported_imgopts 'refcount_bits=1[^0-9]'
 
 # Use -f raw instead of -f $IMGFMT for the NBD connection
 QEMU_IO_NBD="$QEMU_IO -f raw --cache=$CACHEMODE"
diff --git a/tests/qemu-iotests/060.out b/tests/qemu-iotests/060.out
index dc9f6b7..7511189 100644
--- a/tests/qemu-iotests/060.out
+++ b/tests/qemu-iotests/060.out
@@ -18,6 +18,7 @@ cluster_size: 65536
 Format specific information:
     compat: 1.1
     lazy refcounts: false
+    refcount bits: 16
     corrupt: true
 qemu-io: can't open device TEST_DIR/t.IMGFMT: IMGFMT: Image is corrupt; cannot be opened read/write
 read 512/512 bytes at offset 0
diff --git a/tests/qemu-iotests/065 b/tests/qemu-iotests/065
index 8d3a9c9..72aa970 100755
--- a/tests/qemu-iotests/065
+++ b/tests/qemu-iotests/065
@@ -88,34 +88,41 @@ class TestQMP(TestImageInfoSpecific):
 class TestQCow2(TestQemuImgInfo):
     '''Testing a qcow2 version 2 image'''
     img_options = 'compat=0.10'
-    json_compare = { 'compat': '0.10' }
-    human_compare = [ 'compat: 0.10' ]
+    json_compare = { 'compat': '0.10', 'refcount-bits': 16 }
+    human_compare = [ 'compat: 0.10', 'refcount bits: 16' ]
 
 class TestQCow3NotLazy(TestQemuImgInfo):
     '''Testing a qcow2 version 3 image with lazy refcounts disabled'''
     img_options = 'compat=1.1,lazy_refcounts=off'
-    json_compare = { 'compat': '1.1', 'lazy-refcounts': False, 'corrupt': False }
-    human_compare = [ 'compat: 1.1', 'lazy refcounts: false', 'corrupt: false' ]
+    json_compare = { 'compat': '1.1', 'lazy-refcounts': False,
+                     'refcount-bits': 16, 'corrupt': False }
+    human_compare = [ 'compat: 1.1', 'lazy refcounts: false',
+                      'refcount bits: 16', 'corrupt: false' ]
 
 class TestQCow3Lazy(TestQemuImgInfo):
     '''Testing a qcow2 version 3 image with lazy refcounts enabled'''
     img_options = 'compat=1.1,lazy_refcounts=on'
-    json_compare = { 'compat': '1.1', 'lazy-refcounts': True, 'corrupt': False }
-    human_compare = [ 'compat: 1.1', 'lazy refcounts: true', 'corrupt: false' ]
+    json_compare = { 'compat': '1.1', 'lazy-refcounts': True,
+                     'refcount-bits': 16, 'corrupt': False }
+    human_compare = [ 'compat: 1.1', 'lazy refcounts: true',
+                      'refcount bits: 16', 'corrupt: false' ]
 
 class TestQCow3NotLazyQMP(TestQMP):
     '''Testing a qcow2 version 3 image with lazy refcounts disabled, opening
        with lazy refcounts enabled'''
     img_options = 'compat=1.1,lazy_refcounts=off'
     qemu_options = 'lazy-refcounts=on'
-    compare = { 'compat': '1.1', 'lazy-refcounts': False, 'corrupt': False }
+    compare = { 'compat': '1.1', 'lazy-refcounts': False,
+                'refcount-bits': 16, 'corrupt': False }
+
 
 class TestQCow3LazyQMP(TestQMP):
     '''Testing a qcow2 version 3 image with lazy refcounts enabled, opening
        with lazy refcounts disabled'''
     img_options = 'compat=1.1,lazy_refcounts=on'
     qemu_options = 'lazy-refcounts=off'
-    compare = { 'compat': '1.1', 'lazy-refcounts': True, 'corrupt': False }
+    compare = { 'compat': '1.1', 'lazy-refcounts': True,
+                'refcount-bits': 16, 'corrupt': False }
 
 TestImageInfoSpecific = None
 TestQemuImgInfo = None
diff --git a/tests/qemu-iotests/067 b/tests/qemu-iotests/067
index 0508c69..83eefa3 100755
--- a/tests/qemu-iotests/067
+++ b/tests/qemu-iotests/067
@@ -35,6 +35,8 @@ status=1	# failure is the default!
 _supported_fmt qcow2
 _supported_proto file
 _supported_os Linux
+# Because anything other than 16 would change the output of query-block
+_unsupported_imgopts 'refcount_bits=\([^1]\|.\([^6]\|$\)\)'
 
 function do_run_qemu()
 {
diff --git a/tests/qemu-iotests/067.out b/tests/qemu-iotests/067.out
index 00b3eae..6ff41bc 100644
--- a/tests/qemu-iotests/067.out
+++ b/tests/qemu-iotests/067.out
@@ -32,6 +32,7 @@ Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,if=none,id=disk -device virti
                         "data": {
                             "compat": "1.1",
                             "lazy-refcounts": false,
+                            "refcount-bits": 16,
                             "corrupt": false
                         }
                     },
@@ -208,6 +209,7 @@ Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,if=none,id=disk
                         "data": {
                             "compat": "1.1",
                             "lazy-refcounts": false,
+                            "refcount-bits": 16,
                             "corrupt": false
                         }
                     },
@@ -414,6 +416,7 @@ Testing:
                         "data": {
                             "compat": "1.1",
                             "lazy-refcounts": false,
+                            "refcount-bits": 16,
                             "corrupt": false
                         }
                     },
@@ -599,6 +602,7 @@ Testing:
                         "data": {
                             "compat": "1.1",
                             "lazy-refcounts": false,
+                            "refcount-bits": 16,
                             "corrupt": false
                         }
                     },
@@ -710,6 +714,7 @@ Testing:
                         "data": {
                             "compat": "1.1",
                             "lazy-refcounts": false,
+                            "refcount-bits": 16,
                             "corrupt": false
                         }
                     },
diff --git a/tests/qemu-iotests/079 b/tests/qemu-iotests/079
index 6613cfb..ade6efa 100755
--- a/tests/qemu-iotests/079
+++ b/tests/qemu-iotests/079
@@ -42,19 +42,13 @@ _supported_fmt qcow2
 _supported_proto file nfs
 _supported_os Linux
 
-function test_qemu_img()
-{
-    echo qemu-img "$@" | _filter_testdir
-    $QEMU_IMG "$@" 2>&1 | _filter_testdir
-    echo
-}
-
 echo "=== Check option preallocation and cluster_size ==="
 echo
 cluster_sizes="16384 32768 65536 131072 262144 524288 1048576 2097152 4194304"
 
 for s in $cluster_sizes; do
-    test_qemu_img create -f $IMGFMT -o preallocation=metadata,cluster_size=$s "$TEST_IMG" 4G
+    IMGOPTS=$(_optstr_add "$IMGOPTS" "preallocation=metadata,cluster_size=$s") \
+        _make_test_img 4G
 done
 
 # success, all done
diff --git a/tests/qemu-iotests/079.out b/tests/qemu-iotests/079.out
index ef4b8c9..6dc5d57 100644
--- a/tests/qemu-iotests/079.out
+++ b/tests/qemu-iotests/079.out
@@ -1,32 +1,14 @@
 QA output created by 079
 === Check option preallocation and cluster_size ===
 
-qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=16384 TEST_DIR/t.qcow2 4G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=16384 preallocation='metadata' lazy_refcounts=off
-
-qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=32768 TEST_DIR/t.qcow2 4G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=32768 preallocation='metadata' lazy_refcounts=off
-
-qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=65536 TEST_DIR/t.qcow2 4G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=65536 preallocation='metadata' lazy_refcounts=off
-
-qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=131072 TEST_DIR/t.qcow2 4G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=131072 preallocation='metadata' lazy_refcounts=off
-
-qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=262144 TEST_DIR/t.qcow2 4G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=262144 preallocation='metadata' lazy_refcounts=off
-
-qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=524288 TEST_DIR/t.qcow2 4G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=524288 preallocation='metadata' lazy_refcounts=off
-
-qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=1048576 TEST_DIR/t.qcow2 4G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=1048576 preallocation='metadata' lazy_refcounts=off
-
-qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=2097152 TEST_DIR/t.qcow2 4G
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=2097152 preallocation='metadata' lazy_refcounts=off
-
-qemu-img create -f qcow2 -o preallocation=metadata,cluster_size=4194304 TEST_DIR/t.qcow2 4G
-qemu-img: TEST_DIR/t.qcow2: Cluster size must be a power of two between 512 and 2048k
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=4294967296 encryption=off cluster_size=4194304 preallocation='metadata' lazy_refcounts=off
-
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation='metadata'
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation='metadata'
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation='metadata'
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation='metadata'
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation='metadata'
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation='metadata'
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation='metadata'
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation='metadata'
+qemu-img: TEST_DIR/t.IMGFMT: Cluster size must be a power of two between 512 and 2048k
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation='metadata'
 *** done
diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080
index 73795f1..a2c58ae 100755
--- a/tests/qemu-iotests/080
+++ b/tests/qemu-iotests/080
@@ -42,6 +42,8 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto file
 _supported_os Linux
+# Internal snapshots are (currently) impossible with refcount_bits=1
+_unsupported_imgopts 'refcount_bits=1[^0-9]'
 
 header_size=104
 
diff --git a/tests/qemu-iotests/082.out b/tests/qemu-iotests/082.out
index d0234e6..3a749b8 100644
--- a/tests/qemu-iotests/082.out
+++ b/tests/qemu-iotests/082.out
@@ -3,14 +3,14 @@ QA output created by 082
 === create: Options specified more than once ===
 
 Testing: create -f foo -f qcow2 TEST_DIR/t.qcow2 128M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 128M (134217728 bytes)
 cluster_size: 65536
 
 Testing: create -f qcow2 -o cluster_size=4k -o lazy_refcounts=on TEST_DIR/t.qcow2 128M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 encryption=off cluster_size=4096 lazy_refcounts=on
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 encryption=off cluster_size=4096 lazy_refcounts=on refcount_bits=16
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 128M (134217728 bytes)
@@ -18,10 +18,11 @@ cluster_size: 4096
 Format specific information:
     compat: 1.1
     lazy refcounts: true
+    refcount bits: 16
     corrupt: false
 
 Testing: create -f qcow2 -o cluster_size=4k -o lazy_refcounts=on -o cluster_size=8k TEST_DIR/t.qcow2 128M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 encryption=off cluster_size=8192 lazy_refcounts=on
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 encryption=off cluster_size=8192 lazy_refcounts=on refcount_bits=16
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 128M (134217728 bytes)
@@ -29,10 +30,11 @@ cluster_size: 8192
 Format specific information:
     compat: 1.1
     lazy refcounts: true
+    refcount bits: 16
     corrupt: false
 
 Testing: create -f qcow2 -o cluster_size=4k,cluster_size=8k TEST_DIR/t.qcow2 128M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 encryption=off cluster_size=8192 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 encryption=off cluster_size=8192 lazy_refcounts=off refcount_bits=16
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 128M (134217728 bytes)
@@ -50,6 +52,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: create -f qcow2 -o ? TEST_DIR/t.qcow2 128M
@@ -62,6 +65,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: create -f qcow2 -o cluster_size=4k,help TEST_DIR/t.qcow2 128M
@@ -74,6 +78,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: create -f qcow2 -o cluster_size=4k,? TEST_DIR/t.qcow2 128M
@@ -86,6 +91,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: create -f qcow2 -o help,cluster_size=4k TEST_DIR/t.qcow2 128M
@@ -98,6 +104,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: create -f qcow2 -o ?,cluster_size=4k TEST_DIR/t.qcow2 128M
@@ -110,6 +117,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: create -f qcow2 -o cluster_size=4k -o help TEST_DIR/t.qcow2 128M
@@ -122,6 +130,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: create -f qcow2 -o cluster_size=4k -o ? TEST_DIR/t.qcow2 128M
@@ -134,13 +143,14 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: create -f qcow2 -o backing_file=TEST_DIR/t.qcow2,,help TEST_DIR/t.qcow2 128M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/t.qcow2,help' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/t.qcow2,help' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 Testing: create -f qcow2 -o backing_file=TEST_DIR/t.qcow2,,? TEST_DIR/t.qcow2 128M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/t.qcow2,?' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/t.qcow2,?' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 Testing: create -f qcow2 -o backing_file=TEST_DIR/t.qcow2, -o help TEST_DIR/t.qcow2 128M
 qemu-img: Invalid option list: backing_file=TEST_DIR/t.qcow2,
@@ -161,6 +171,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 
 Testing: create -o help
 Supported options:
@@ -169,7 +180,7 @@ size             Virtual disk size
 === convert: Options specified more than once ===
 
 Testing: create -f qcow2 TEST_DIR/t.qcow2 128M
-Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 Testing: convert -f foo -f qcow2 TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
 image: TEST_DIR/t.IMGFMT.base
@@ -190,6 +201,7 @@ cluster_size: 4096
 Format specific information:
     compat: 1.1
     lazy refcounts: true
+    refcount bits: 16
     corrupt: false
 
 Testing: convert -O qcow2 -o cluster_size=4k -o lazy_refcounts=on -o cluster_size=8k TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -200,6 +212,7 @@ cluster_size: 8192
 Format specific information:
     compat: 1.1
     lazy refcounts: true
+    refcount bits: 16
     corrupt: false
 
 Testing: convert -O qcow2 -o cluster_size=4k,cluster_size=8k TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -220,6 +233,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: convert -O qcow2 -o ? TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -232,6 +246,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: convert -O qcow2 -o cluster_size=4k,help TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -244,6 +259,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: convert -O qcow2 -o cluster_size=4k,? TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -256,6 +272,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: convert -O qcow2 -o help,cluster_size=4k TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -268,6 +285,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: convert -O qcow2 -o ?,cluster_size=4k TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -280,6 +298,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: convert -O qcow2 -o cluster_size=4k -o help TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -292,6 +311,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: convert -O qcow2 -o cluster_size=4k -o ? TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -304,6 +324,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: convert -O qcow2 -o backing_file=TEST_DIR/t.qcow2,,help TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
@@ -331,6 +352,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 
 Testing: convert -o help
 Supported options:
@@ -346,6 +368,7 @@ cluster_size: 65536
 Format specific information:
     compat: 1.1
     lazy refcounts: true
+    refcount bits: 16
     corrupt: false
 
 Testing: amend -f qcow2 -o size=130M -o lazy_refcounts=off TEST_DIR/t.qcow2
@@ -356,6 +379,7 @@ cluster_size: 65536
 Format specific information:
     compat: 1.1
     lazy refcounts: false
+    refcount bits: 16
     corrupt: false
 
 Testing: amend -f qcow2 -o size=8M -o lazy_refcounts=on -o size=132M TEST_DIR/t.qcow2
@@ -366,6 +390,7 @@ cluster_size: 65536
 Format specific information:
     compat: 1.1
     lazy refcounts: true
+    refcount bits: 16
     corrupt: false
 
 Testing: amend -f qcow2 -o size=4M,size=148M TEST_DIR/t.qcow2
@@ -386,6 +411,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: amend -f qcow2 -o ? TEST_DIR/t.qcow2
@@ -398,6 +424,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: amend -f qcow2 -o cluster_size=4k,help TEST_DIR/t.qcow2
@@ -410,6 +437,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: amend -f qcow2 -o cluster_size=4k,? TEST_DIR/t.qcow2
@@ -422,6 +450,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: amend -f qcow2 -o help,cluster_size=4k TEST_DIR/t.qcow2
@@ -434,6 +463,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: amend -f qcow2 -o ?,cluster_size=4k TEST_DIR/t.qcow2
@@ -446,6 +476,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: amend -f qcow2 -o cluster_size=4k -o help TEST_DIR/t.qcow2
@@ -458,6 +489,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: amend -f qcow2 -o cluster_size=4k -o ? TEST_DIR/t.qcow2
@@ -470,6 +502,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 nocow            Turn off copy-on-write (valid only on btrfs)
 
 Testing: amend -f qcow2 -o backing_file=TEST_DIR/t.qcow2,,help TEST_DIR/t.qcow2
@@ -499,6 +532,7 @@ encryption       Encrypt the image
 cluster_size     qcow2 cluster size
 preallocation    Preallocation mode (allowed values: off, metadata, falloc, full)
 lazy_refcounts   Postpone refcount updates
+refcount_bits    Width of a reference count entry in bits
 
 Testing: convert -o help
 Supported options:
diff --git a/tests/qemu-iotests/085.out b/tests/qemu-iotests/085.out
index 0f2b17f..5eb8b94 100644
--- a/tests/qemu-iotests/085.out
+++ b/tests/qemu-iotests/085.out
@@ -11,7 +11,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 
 === Create a single snapshot on virtio0 ===
 
-Formatting 'TEST_DIR/1-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/t.qcow2.orig' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/1-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/t.qcow2.orig' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 {"return": {}}
 
 === Invalid command - missing device and nodename ===
@@ -25,31 +25,31 @@ Formatting 'TEST_DIR/1-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file
 
 === Create several transactional group snapshots ===
 
-Formatting 'TEST_DIR/2-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/1-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
-Formatting 'TEST_DIR/2-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/t.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/2-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/1-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/2-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/t.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 {"return": {}}
-Formatting 'TEST_DIR/3-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/2-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
-Formatting 'TEST_DIR/3-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/2-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/3-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/2-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/3-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/2-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 {"return": {}}
-Formatting 'TEST_DIR/4-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/3-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
-Formatting 'TEST_DIR/4-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/3-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/4-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/3-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/4-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/3-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 {"return": {}}
-Formatting 'TEST_DIR/5-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/4-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
-Formatting 'TEST_DIR/5-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/4-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/5-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/4-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/5-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/4-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 {"return": {}}
-Formatting 'TEST_DIR/6-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/5-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
-Formatting 'TEST_DIR/6-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/5-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/6-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/5-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/6-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/5-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 {"return": {}}
-Formatting 'TEST_DIR/7-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/6-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
-Formatting 'TEST_DIR/7-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/6-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/7-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/6-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/7-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/6-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 {"return": {}}
-Formatting 'TEST_DIR/8-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/7-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
-Formatting 'TEST_DIR/8-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/7-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/8-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/7-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/8-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/7-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 {"return": {}}
-Formatting 'TEST_DIR/9-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/8-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
-Formatting 'TEST_DIR/9-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/8-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/9-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/8-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/9-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/8-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 {"return": {}}
-Formatting 'TEST_DIR/10-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/9-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
-Formatting 'TEST_DIR/10-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/9-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
+Formatting 'TEST_DIR/10-snapshot-v0.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/9-snapshot-v0.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
+Formatting 'TEST_DIR/10-snapshot-v1.qcow2', fmt=qcow2 size=134217728 backing_file='TEST_DIR/9-snapshot-v1.qcow2' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
 {"return": {}}
 *** done
diff --git a/tests/qemu-iotests/089 b/tests/qemu-iotests/089
index 6f74cec..3e0038d 100755
--- a/tests/qemu-iotests/089
+++ b/tests/qemu-iotests/089
@@ -41,6 +41,8 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto file
 _supported_os Linux
+# Because anything other than 16 would change the output of qemu_io -c info
+_unsupported_imgopts 'refcount_bits=\([^1]\|.\([^6]\|$\)\)'
 
 # Using an image filename containing quotation marks will render the JSON data
 # below invalid. In that case, we have little choice but simply not to run this
diff --git a/tests/qemu-iotests/089.out b/tests/qemu-iotests/089.out
index a6d3711..5b541a3 100644
--- a/tests/qemu-iotests/089.out
+++ b/tests/qemu-iotests/089.out
@@ -43,6 +43,7 @@ vm state offset: 512 MiB
 Format specific information:
     compat: 1.1
     lazy refcounts: false
+    refcount bits: 16
     corrupt: false
 format name: IMGFMT
 cluster size: 64 KiB
@@ -50,5 +51,6 @@ vm state offset: 512 MiB
 Format specific information:
     compat: 1.1
     lazy refcounts: false
+    refcount bits: 16
     corrupt: false
 *** done
diff --git a/tests/qemu-iotests/104 b/tests/qemu-iotests/104
index f32752b..2e35ea8 100755
--- a/tests/qemu-iotests/104
+++ b/tests/qemu-iotests/104
@@ -34,7 +34,7 @@ trap "exit \$status" 0 1 2 3 15
 . ./common.rc
 . ./common.filter
 
-_supported_fmt generic
+_supported_fmt raw qcow qcow2 qed vdi vmdk vhdx
 _supported_proto generic
 _supported_os Linux
 
diff --git a/tests/qemu-iotests/108 b/tests/qemu-iotests/108
index 12fc92a..ce44749 100755
--- a/tests/qemu-iotests/108
+++ b/tests/qemu-iotests/108
@@ -43,6 +43,8 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto file
 _supported_os Linux
+# This test directly modifies a refblock so it relies on refcount_bits being 16
+_unsupported_imgopts 'refcount_bits=\([^1]\|.\([^6]\|$\)\)'
 
 echo
 echo '=== Repairing an image without any refcount table ==='
diff --git a/tests/qemu-iotests/112 b/tests/qemu-iotests/112
new file mode 100755
index 0000000..3f054a3
--- /dev/null
+++ b/tests/qemu-iotests/112
@@ -0,0 +1,187 @@
+#!/bin/bash
+#
+# Test cases for different refcount_bits values
+#
+# Copyright (C) 2015 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# creator
+owner=mreitz@redhat.com
+
+seq="$(basename $0)"
+echo "QA output created by $seq"
+
+here="$PWD"
+tmp=/tmp/$$
+status=1	# failure is the default!
+
+_cleanup()
+{
+	_cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+# This tests qcow2-specific low-level functionality
+_supported_fmt qcow2
+_supported_proto file
+_supported_os Linux
+# This test will set refcount_bits on its own which would conflict with the
+# manual setting; compat will be overridden as well
+_unsupported_imgopts refcount_bits 'compat=0.10'
+
+function print_refcount_bits()
+{
+    $QEMU_IMG info "$TEST_IMG" | sed -n '/refcount bits:/ s/^ *//p'
+}
+
+echo
+echo '=== refcount_bits limits ==='
+echo
+
+# Must be positive (non-zero)
+IMGOPTS="$IMGOPTS,refcount_bits=0" _make_test_img 64M
+# Must be positive (non-negative)
+IMGOPTS="$IMGOPTS,refcount_bits=-1" _make_test_img 64M
+# May not exceed 64
+IMGOPTS="$IMGOPTS,refcount_bits=128" _make_test_img 64M
+# Must be a power of two
+IMGOPTS="$IMGOPTS,refcount_bits=42" _make_test_img 64M
+
+# 1 is the minimum
+IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 64M
+print_refcount_bits
+
+# 64 is the maximum
+IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 64M
+print_refcount_bits
+
+# 16 is the default
+_make_test_img 64M
+print_refcount_bits
+
+echo
+echo '=== refcount_bits and compat=0.10 ==='
+echo
+
+# Should work
+IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=16" _make_test_img 64M
+print_refcount_bits
+
+# Should not work
+IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=1" _make_test_img 64M
+IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=64" _make_test_img 64M
+
+
+echo
+echo '=== Snapshot limit on refcount_bits=1 ==='
+echo
+
+IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 64M
+print_refcount_bits
+
+$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io
+
+# Should fail for now; in the future, this might be supported by automatically
+# copying all clusters with overflowing refcount
+$QEMU_IMG snapshot -c foo "$TEST_IMG"
+
+# The new L1 table could/should be leaked
+_check_test_img
+
+echo
+echo '=== Snapshot limit on refcount_bits=2 ==='
+echo
+
+IMGOPTS="$IMGOPTS,refcount_bits=2" _make_test_img 64M
+print_refcount_bits
+
+$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io
+
+# Should succeed
+$QEMU_IMG snapshot -c foo "$TEST_IMG"
+$QEMU_IMG snapshot -c bar "$TEST_IMG"
+# Should fail (4th reference)
+$QEMU_IMG snapshot -c baz "$TEST_IMG"
+
+# The new L1 table could/should be leaked
+_check_test_img
+
+echo
+echo '=== Compressed clusters with refcount_bits=1 ==='
+echo
+
+IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 64M
+print_refcount_bits
+
+# Both should fit into a single host cluster; instead of failing to increase the
+# refcount of that cluster, qemu should just allocate a new cluster and make
+# this operation succeed
+$QEMU_IO -c 'write -P 0 -c  0  64k' \
+         -c 'write -P 1 -c 64k 64k' \
+         "$TEST_IMG" | _filter_qemu_io
+
+_check_test_img
+
+echo
+echo '=== MSb set in 64 bit refcount ==='
+echo
+
+IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 64M
+print_refcount_bits
+
+$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io
+
+# Set the MSb in the refblock entry of the data cluster
+poke_file "$TEST_IMG" $((0x20028)) "\x80\x00\x00\x00\x00\x00\x00\x00"
+
+# Clear OFLAG_COPIED in the L2 entry of the data cluster
+poke_file "$TEST_IMG" $((0x40000)) "\x00\x00\x00\x00\x00\x05\x00\x00"
+
+# Try to write to that cluster (should work, even though the MSb is set)
+$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io
+
+echo
+echo '=== Snapshot on maximum 64 bit refcount value ==='
+echo
+
+IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 64M
+print_refcount_bits
+
+$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io
+
+# Set the refblock entry to the maximum value possible
+poke_file "$TEST_IMG" $((0x20028)) "\xff\xff\xff\xff\xff\xff\xff\xff"
+
+# Clear OFLAG_COPIED in the L2 entry of the data cluster
+poke_file "$TEST_IMG" $((0x40000)) "\x00\x00\x00\x00\x00\x05\x00\x00"
+
+# Try a snapshot (should correctly identify the overflow; may work in the future
+# by falling back to COW)
+$QEMU_IMG snapshot -c foo "$TEST_IMG"
+
+# The new L1 table could/should be leaked; and obviously the data cluster is
+# leaked (refcount=UINT64_MAX reference=1)
+_check_test_img
+
+
+# success, all done
+echo '*** done'
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/112.out b/tests/qemu-iotests/112.out
new file mode 100644
index 0000000..9a98633
--- /dev/null
+++ b/tests/qemu-iotests/112.out
@@ -0,0 +1,84 @@
+QA output created by 112
+
+=== refcount_bits limits ===
+
+qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 refcount_bits=-1
+qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+refcount bits: 1
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+refcount bits: 64
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+refcount bits: 16
+
+=== refcount_bits and compat=0.10 ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+refcount bits: 16
+qemu-img: TEST_DIR/t.IMGFMT: Different refcount widths than 16 bits require compatibility level 1.1 or above (use compat=1.1 or greater)
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+qemu-img: TEST_DIR/t.IMGFMT: Different refcount widths than 16 bits require compatibility level 1.1 or above (use compat=1.1 or greater)
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+
+=== Snapshot limit on refcount_bits=1 ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+refcount bits: 1
+wrote 512/512 bytes at offset 0
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+qemu-img: Could not create snapshot 'foo': -22 (Invalid argument)
+Leaked cluster 6 refcount=1 reference=0
+
+1 leaked clusters were found on the image.
+This means waste of disk space, but no harm to data.
+
+=== Snapshot limit on refcount_bits=2 ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+refcount bits: 2
+wrote 512/512 bytes at offset 0
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+qemu-img: Could not create snapshot 'baz': -22 (Invalid argument)
+Leaked cluster 7 refcount=1 reference=0
+
+1 leaked clusters were found on the image.
+This means waste of disk space, but no harm to data.
+
+=== Compressed clusters with refcount_bits=1 ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+refcount bits: 1
+wrote 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+
+=== MSb set in 64 bit refcount ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+refcount bits: 64
+wrote 512/512 bytes at offset 0
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 512/512 bytes at offset 0
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+=== Snapshot on maximum 64 bit refcount value ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+refcount bits: 64
+wrote 512/512 bytes at offset 0
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+qemu-img: Could not create snapshot 'foo': -22 (Invalid argument)
+Leaked cluster 5 refcount=18446744073709551615 reference=1
+Leaked cluster 6 refcount=1 reference=0
+
+2 leaked clusters were found on the image.
+This means waste of disk space, but no harm to data.
+*** done
diff --git a/tests/qemu-iotests/006 b/tests/qemu-iotests/128
index 0c0cf5d..249a865 100755
--- a/tests/qemu-iotests/006
+++ b/tests/qemu-iotests/128
@@ -1,9 +1,8 @@
 #!/bin/bash
 #
-# Make sure qemu-img rejects > 127GB images for the vpc format as the format
-# doesn't support this.
+# Test that opening O_DIRECT succeeds when image file I/O produces EIO
 #
-# Copyright (C) 2009 Red Hat, Inc.
+# Copyright (C) 2015 Red Hat, Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -20,7 +19,7 @@
 #
 
 # creator
-owner=hch@lst.de
+owner=stefanha@redhat.com
 
 seq=`basename $0`
 echo "QA output created by $seq"
@@ -29,9 +28,34 @@ here=`pwd`
 tmp=/tmp/$$
 status=1	# failure is the default!
 
+devname="eiodev$$"
+
+_setup_eiodev()
+{
+	# This test should either be run as root or with passwordless sudo
+	for cmd in "" "sudo -n"; do
+		echo "0 $((1024 * 1024 * 1024 / 512)) error" | \
+			$cmd dmsetup create "$devname" 2>/dev/null
+		if [ "$?" -eq 0 ]; then
+			return
+		fi
+	done
+	_notrun "root privileges required to run dmsetup"
+}
+
+_cleanup_eiodev()
+{
+	for cmd in "" "sudo -n"; do
+		$cmd dmsetup remove "$devname" 2>/dev/null
+		if [ "$?" -eq 0 ]; then
+			return
+		fi
+	done
+}
+
 _cleanup()
 {
-	_cleanup_test_img
+	_cleanup_eiodev
 }
 trap "_cleanup; exit \$status" 0 1 2 3 15
 
@@ -39,14 +63,18 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.rc
 . ./common.filter
 
-_supported_fmt vpc
-_supported_proto generic
+_supported_fmt raw
+_supported_proto file
 _supported_os Linux
 
+_setup_eiodev
+
+TEST_IMG="/dev/mapper/$devname"
 
 echo
-echo "creating 128GB image"
-_make_test_img 128G
+echo "== reading from error device =="
+# Opening image should succeed but the read operation should fail
+$QEMU_IO --format "$IMGFMT" --nocache -c "read 0 65536" "$TEST_IMG" | _filter_qemu_io
 
 # success, all done
 echo "*** done"
diff --git a/tests/qemu-iotests/128.out b/tests/qemu-iotests/128.out
new file mode 100644
index 0000000..4e43f5f
--- /dev/null
+++ b/tests/qemu-iotests/128.out
@@ -0,0 +1,5 @@
+QA output created by 128
+
+== reading from error device ==
+read failed: Input/output error
+*** done
diff --git a/tests/qemu-iotests/common.filter b/tests/qemu-iotests/common.filter
index 06e1bb0..012a812 100644
--- a/tests/qemu-iotests/common.filter
+++ b/tests/qemu-iotests/common.filter
@@ -192,7 +192,8 @@ _filter_img_create()
         -e "s# block_size=[0-9]\\+##g" \
         -e "s# block_state_zero=\\(on\\|off\\)##g" \
         -e "s# log_size=[0-9]\\+##g" \
-        -e "s/archipelago:a/TEST_DIR\//g"
+        -e "s/archipelago:a/TEST_DIR\//g" \
+        -e "s# refcount_bits=[0-9]\\+##g"
 }
 
 _filter_img_info()
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 0d3b95c..71f19d4 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -12,7 +12,7 @@
 003 rw auto
 004 rw auto quick
 005 img auto quick
-006 img auto
+# 006 was removed, do not reuse
 007 snapshot auto
 008 rw auto quick
 009 rw auto quick
@@ -116,7 +116,9 @@
 109 rw auto
 110 rw auto backing quick
 111 rw auto quick
+112 rw auto
 113 rw auto quick
 114 rw auto quick
 116 rw auto quick
 123 rw auto quick
+128 rw auto quick