Commit Graph

27 Commits

Author SHA1 Message Date
Connor Kuehl 785ec4b1b9 block: Clarify error messages pertaining to 'node-name'
Some error messages contain ambiguous representations of the 'node-name'
parameter. This can be particularly confusing when exchanging QMP
messages (C = client, S = server):

C: {"execute": "block_resize", "arguments": { "device": "my_file", "size": 26843545600 }}
S: {"error": {"class": "GenericError", "desc": "Cannot find device=my_file nor node_name="}}
                                                                               ^^^^^^^^^

This error message suggests one could send a message with a key called
'node_name':

C: {"execute": "block_resize", "arguments": { "node_name": "my_file", "size": 26843545600 }}
                                               ^^^^^^^^^

but using the underscore is actually incorrect, the parameter should be
'node-name':

S: {"error": {"class": "GenericError", "desc": "Parameter 'node_name' is unexpected"}}

This behavior was uncovered in bz1651437, but I ended up going down a
rabbit hole looking for other areas where this miscommunication might
occur and changing those accordingly as well.

Fixes: https://bugzilla.redhat.com/1651437
Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Message-Id: <20210305151929.1947331-2-ckuehl@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-03-08 14:56:55 +01:00
Maxim Levitsky cbb32e79dd iotests: filter few more luks specific create options
This allows more tests to be able to have same output on both qcow2 luks encrypted images
and raw luks images

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200625125548.870061-3-mreitz@redhat.com>
2020-07-06 08:33:06 +02:00
Dominik Csapak 9254893882 qmp: Split ShutdownCause host-qmp into quit and system-reset
It is interesting to know whether the shutdown cause was 'quit' or
'reset', especially when using "--no-reboot". In that case, a management
layer can now determine if the guest wanted a reboot or shutdown, and
can act accordingly.

Changes the output of the reason in the iotests from 'host-qmp' to
'host-qmp-quit'. This does not break compatibility because
the field was introduced in the same version.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Message-Id: <20181205110131.23049-4-d.csapak@proxmox.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-18 07:55:47 +01:00
Dominik Csapak ecd7a0d5bb qmp: Add reason to SHUTDOWN and RESET events
This makes it possible to determine what the exact reason was for
a RESET or a SHUTDOWN. A management layer might need the specific reason
of those events to determine which cleanups or other actions it needs to do.

This patch also updates the iotests to the new expected output that includes
the reason.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Message-Id: <20181205110131.23049-3-d.csapak@proxmox.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-18 07:55:47 +01:00
Daniel P. Berrange 426d52d88c qcow2: add iotests to cover LUKS encryption support
This extends the 087 iotest to cover LUKS encryption when doing
blockdev-add.

Two further tests are added to validate read/write of LUKS
encrypted images with a single file and with a backing file.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170623162419.26068-15-berrange@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:56 +02:00
Daniel P. Berrange b25b387fa5 qcow2: convert QCow2 to use QCryptoBlock for encryption
This converts the qcow2 driver to make use of the QCryptoBlock
APIs for encrypting image content, using the legacy QCow2 AES
scheme.

With this change it is now required to use the QCryptoSecret
object for providing passwords, instead of the current block
password APIs / interactive prompting.

  $QEMU \
    -object secret,id=sec0,file=/home/berrange/encrypted.pw \
    -drive file=/home/berrange/encrypted.qcow2,encrypt.key-secret=sec0

The test 087 could be simplified since there is no longer a
difference in behaviour when using blockdev_add with encrypted
images for the running vs stopped CPU state.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170623162419.26068-12-berrange@redhat.com
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:56 +02:00
Eric Blake 08fba7ac9b shutdown: Expose bool cause in SHUTDOWN and RESET events
Libvirt would like to be able to distinguish between a SHUTDOWN
event triggered solely by guest request and one triggered by a
SIGTERM or other action on the host.  While qemu_kill_report() was
already able to give different output to stderr based on whether a
shutdown was triggered by a host signal (but NOT by a host UI event,
such as clicking the X on the window), that information was then
lost to management.  The previous patches improved things to use an
enum throughout all callsites, so now we have something ready to
expose through QMP.

Note that for now, the decision was to expose ONLY a boolean,
rather than promoting ShutdownCause to a QAPI enum; this is because
libvirt has not expressed an interest in anything finer-grained.
We can still add additional details, in a backwards-compatible
manner, if a need later arises (if the addition happens before 2.10,
we can replace the bool with an enum; otherwise, the enum will have
to be in addition to the bool); this patch merely adds a helper
shutdown_caused_by_guest() to map the internal enum into the
external boolean.

Update expected iotest outputs to match the new data (complete
coverage of the affected tests is obtained by -raw, -qcow2, and -nbd).

Here is output from 'virsh qemu-monitor-event --loop' with the
patch installed:

event SHUTDOWN at 1492639680.731251 for domain fedora_13: {"guest":true}
event STOP at 1492639680.732116 for domain fedora_13: <null>
event SHUTDOWN at 1492639680.732830 for domain fedora_13: {"guest":false}

Note that libvirt runs qemu with -no-shutdown: the first SHUTDOWN event
was triggered by an action I took directly in the guest (shutdown -h),
at which point qemu stops the vcpus and waits for libvirt to do any
final cleanups; the second SHUTDOWN event is the result of libvirt
sending SIGTERM now that it has completed cleanup.  Libvirt is already
smart enough to only feed the first qemu SHUTDOWN event to the end user
(remember, virsh qemu-monitor-event is a low-level debugging interface
that is explicitly unsupported by libvirt, so it sees things that normal
end users do not); changing qemu to emit SHUTDOWN only once is outside
the scope of this series.

See also https://bugzilla.redhat.com/1384007

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170515214114.15442-6-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-05-23 13:28:17 +02:00
Marc-André Lureau 1382d4abdf qapi: return a 'missing parameter' error
The 'old' dispatch code returned a QERR_MISSING_PARAMETER for missing
parameters, but the qapi qmp_dispatch() code uses
QERR_INVALID_PARAMETER_TYPE.

Improve qapi code to return QERR_MISSING_PARAMETER where
appropriate.

Fix expected error message in iotests.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20160930095948.3154-4-marcandre.lureau@redhat.com>
[Drop incorrect error_setg() from qmp_input_type_any() and
qmp_input_type_null()]
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-10-07 19:22:11 +02:00
Kevin Wolf 0ffcdd9c06 block: Drop aio/cache consistency check from qmp_blockdev_add()
The TODO comment has been addressed a while ago and this is now checked
in raw-posix, so we don't have to special case this in blockdev-add any
more.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-09-29 14:13:38 +02:00
Kevin Wolf 9ec8873e68 block: Remove BB interface from blockdev-add/del
With this patch, blockdev-add always works on a node level, i.e. it
creates a BDS, but no BB. Consequently, x-blockdev-del doesn't need the
'device' option any more, but 'node-name' becomes mandatory.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-09-23 13:45:36 +02:00
Kevin Wolf 5feb08ed8f qemu-iotests/087: Avoid blockdev-add with id
We want to remove the 'id' option for blockdev-add. This removes one
user of the option and makes it use only node names.

The test cases that test conflicts between the 'id' option to
blockdev-add and existing block devices or the 'node-name' of the same
command can be removed because it won't be possible to specify this at
the end of the series.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-09-23 13:45:36 +02:00
Daniel P. Berrange 8c0dcbc4ad block: drop support for using qcow[2] encryption with system emulators
Back in the 2.3.0 release we declared qcow[2] encryption as
deprecated, warning people that it would be removed in a future
release.

  commit a1f688f415
  Author: Markus Armbruster <armbru@redhat.com>
  Date:   Fri Mar 13 21:09:40 2015 +0100

    block: Deprecate QCOW/QCOW2 encryption

The code still exists today, but by a (happy?) accident we entirely
broke the ability to use qcow[2] encryption in the system emulators
in the 2.4.0 release due to

  commit 8336aafae1
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Tue May 12 17:09:18 2015 +0100

    qcow2/qcow: protect against uninitialized encryption key

This commit was designed to prevent future coding bugs which
might cause QEMU to read/write data on an encrypted block
device in plain text mode before a decryption key is set.

It turns out this preventative measure was a little too good,
because we already had a long standing bug where QEMU read
encrypted data in plain text mode during system emulator
startup, in order to guess disk geometry:

  Thread 10 (Thread 0x7fffd3fff700 (LWP 30373)):
  #0  0x00007fffe90b1a28 in raise () at /lib64/libc.so.6
  #1  0x00007fffe90b362a in abort () at /lib64/libc.so.6
  #2  0x00007fffe90aa227 in __assert_fail_base () at /lib64/libc.so.6
  #3  0x00007fffe90aa2d2 in  () at /lib64/libc.so.6
  #4  0x000055555587ae19 in qcow2_co_readv (bs=0x5555562accb0, sector_num=0, remaining_sectors=1, qiov=0x7fffffffd260) at block/qcow2.c:1229
  #5  0x000055555589b60d in bdrv_aligned_preadv (bs=bs@entry=0x5555562accb0, req=req@entry=0x7fffd3ffea50, offset=offset@entry=0, bytes=bytes@entry=512, align=align@entry=512, qiov=qiov@entry=0x7fffffffd260, flags=0) at block/io.c:908
  #6  0x000055555589b8bc in bdrv_co_do_preadv (bs=0x5555562accb0, offset=0, bytes=512, qiov=0x7fffffffd260, flags=<optimized out>) at block/io.c:999
  #7  0x000055555589c375 in bdrv_rw_co_entry (opaque=0x7fffffffd210) at block/io.c:544
  #8  0x000055555586933b in coroutine_thread (opaque=0x555557876310) at coroutine-gthread.c:134
  #9  0x00007ffff64e1835 in g_thread_proxy (data=0x5555562b5590) at gthread.c:778
  #10 0x00007ffff6bb760a in start_thread () at /lib64/libpthread.so.0
  #11 0x00007fffe917f59d in clone () at /lib64/libc.so.6

  Thread 1 (Thread 0x7ffff7ecab40 (LWP 30343)):
  #0  0x00007fffe91797a9 in syscall () at /lib64/libc.so.6
  #1  0x00007ffff64ff87f in g_cond_wait (cond=cond@entry=0x555555e085f0 <coroutine_cond>, mutex=mutex@entry=0x555555e08600 <coroutine_lock>) at gthread-posix.c:1397
  #2  0x00005555558692c3 in qemu_coroutine_switch (co=<optimized out>) at coroutine-gthread.c:117
  #3  0x00005555558692c3 in qemu_coroutine_switch (from_=0x5555562b5e30, to_=to_@entry=0x555557876310, action=action@entry=COROUTINE_ENTER) at coroutine-gthread.c:175
  #4  0x0000555555868a90 in qemu_coroutine_enter (co=0x555557876310, opaque=0x0) at qemu-coroutine.c:116
  #5  0x0000555555859b84 in thread_pool_completion_bh (opaque=0x7fffd40010e0) at thread-pool.c:187
  #6  0x0000555555859514 in aio_bh_poll (ctx=ctx@entry=0x5555562953b0) at async.c:85
  #7  0x0000555555864d10 in aio_dispatch (ctx=ctx@entry=0x5555562953b0) at aio-posix.c:135
  #8  0x0000555555864f75 in aio_poll (ctx=ctx@entry=0x5555562953b0, blocking=blocking@entry=true) at aio-posix.c:291
  #9  0x000055555589c40d in bdrv_prwv_co (bs=bs@entry=0x5555562accb0, offset=offset@entry=0, qiov=qiov@entry=0x7fffffffd260, is_write=is_write@entry=false, flags=flags@entry=(unknown: 0)) at block/io.c:591
  #10 0x000055555589c503 in bdrv_rw_co (bs=bs@entry=0x5555562accb0, sector_num=sector_num@entry=0, buf=buf@entry=0x7fffffffd2e0 "\321,", nb_sectors=nb_sectors@entry=21845, is_write=is_write@entry=false, flags=flags@entry=(unknown: 0)) at block/io.c:614
  #11 0x000055555589c562 in bdrv_read_unthrottled (nb_sectors=21845, buf=0x7fffffffd2e0 "\321,", sector_num=0, bs=0x5555562accb0) at block/io.c:622
  #12 0x000055555589c562 in bdrv_read_unthrottled (bs=0x5555562accb0, sector_num=sector_num@entry=0, buf=buf@entry=0x7fffffffd2e0 "\321,", nb_sectors=nb_sectors@entry=21845) at block/io.c:634
    nb_sectors@entry=1) at block/block-backend.c:504
  #14 0x0000555555752e9f in guess_disk_lchs (blk=blk@entry=0x5555562a5290, pcylinders=pcylinders@entry=0x7fffffffd52c, pheads=pheads@entry=0x7fffffffd530, psectors=psectors@entry=0x7fffffffd534) at hw/block/hd-geometry.c:68
  #15 0x0000555555752ff7 in hd_geometry_guess (blk=0x5555562a5290, pcyls=pcyls@entry=0x555557875d1c, pheads=pheads@entry=0x555557875d20, psecs=psecs@entry=0x555557875d24, ptrans=ptrans@entry=0x555557875d28) at hw/block/hd-geometry.c:133
  #16 0x0000555555752b87 in blkconf_geometry (conf=conf@entry=0x555557875d00, ptrans=ptrans@entry=0x555557875d28, cyls_max=cyls_max@entry=65536, heads_max=heads_max@entry=16, secs_max=secs_max@entry=255, errp=errp@entry=0x7fffffffd5e0) at hw/block/block.c:71
  #17 0x0000555555799bc4 in ide_dev_initfn (dev=0x555557875c80, kind=IDE_HD) at hw/ide/qdev.c:174
  #18 0x0000555555768394 in device_realize (dev=0x555557875c80, errp=0x7fffffffd640) at hw/core/qdev.c:247
  #19 0x0000555555769a81 in device_set_realized (obj=0x555557875c80, value=<optimized out>, errp=0x7fffffffd730) at hw/core/qdev.c:1058
  #20 0x00005555558240ce in property_set_bool (obj=0x555557875c80, v=<optimized out>, opaque=0x555557875de0, name=<optimized out>, errp=0x7fffffffd730)
        at qom/object.c:1514
  #21 0x0000555555826c87 in object_property_set_qobject (obj=obj@entry=0x555557875c80, value=value@entry=0x55555784bcb0, name=name@entry=0x55555591cb3d "realized", errp=errp@entry=0x7fffffffd730) at qom/qom-qobject.c:24
  #22 0x0000555555825760 in object_property_set_bool (obj=obj@entry=0x555557875c80, value=value@entry=true, name=name@entry=0x55555591cb3d "realized", errp=errp@entry=0x7fffffffd730) at qom/object.c:905
  #23 0x000055555576897b in qdev_init_nofail (dev=dev@entry=0x555557875c80) at hw/core/qdev.c:380
  #24 0x0000555555799ead in ide_create_drive (bus=bus@entry=0x555557629630, unit=unit@entry=0, drive=0x5555562b77e0) at hw/ide/qdev.c:122
  #25 0x000055555579a746 in pci_ide_create_devs (dev=dev@entry=0x555557628db0, hd_table=hd_table@entry=0x7fffffffd830) at hw/ide/pci.c:440
  #26 0x000055555579b165 in pci_piix3_ide_init (bus=<optimized out>, hd_table=0x7fffffffd830, devfn=<optimized out>) at hw/ide/piix.c:218
  #27 0x000055555568ca55 in pc_init1 (machine=0x5555562960a0, pci_enabled=1, kvmclock_enabled=<optimized out>) at /home/berrange/src/virt/qemu/hw/i386/pc_piix.c:256
  #28 0x0000555555603ab2 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4249

So the safety net is correctly preventing QEMU reading cipher
text as if it were plain text, during startup and aborting QEMU
to avoid bad usage of this data.

For added fun this bug only happens if the encrypted qcow2
file happens to have data written to the first cluster,
otherwise the cluster won't be allocated and so qcow2 would
not try the decryption routines at all, just return all 0's.

That no one even noticed, let alone reported, this bug that
has shipped in 2.4.0, 2.5.0 and 2.6.0 shows that the number
of actual users of encrypted qcow2 is approximately zero.

So rather than fix the crash, and backport it to stable
releases, just go ahead with what we have warned users about
and disable any use of qcow2 encryption in the system
emulators. qemu-img/qemu-io/qemu-nbd are still able to access
qcow2 encrypted images for the sake of data conversion.

In the future, qcow2 will gain support for the alternative
luks format, but when this happens it'll be using the
'-object secret' infrastructure for getting keys, which
avoids this problematic scenario entirely.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-16 15:19:55 +02:00
Daniel P. Berrange e6ff69bf5e block: move encryption deprecation warning into qcow code
For a couple of releases we have been warning

  Encrypted images are deprecated
  Support for them will be removed in a future release.
  You can use 'qemu-img convert' to convert your image to an unencrypted one.

This warning was issued by system emulators, qemu-img, qemu-nbd
and qemu-io. Such a broad warning was issued because the original
intention was to rip out all the code for dealing with encryption
inside the QEMU block layer APIs.

The new block encryption framework used for the LUKS driver does
not rely on the unloved block layer API for encryption keys,
instead using the QOM 'secret' object type. It is thus no longer
appropriate to warn about encryption unconditionally.

When the qcow/qcow2 drivers are converted to use the new encryption
framework too, it will be practical to keep AES-CBC support present
for use in qemu-img, qemu-io & qemu-nbd to allow for interoperability
with older QEMU versions and liberation of data from existing encrypted
qcow2 files.

This change moves the warning out of the generic block code and
into the qcow/qcow2 drivers. Further, the warning is set to only
appear when running the system emulators, since qemu-img, qemu-io,
qemu-nbd are expected to support qcow2 encryption long term now that
the maint burden has been eliminated.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-30 12:12:15 +02:00
Max Reitz efaa7c4eeb blockdev: Split monitor reference from BB creation
Before this patch, blk_new() automatically assigned a name to the new
BlockBackend and considered it referenced by the monitor. This patch
removes the implicit monitor_add_blk() call from blk_new() (and
consequently the monitor_remove_blk() call from blk_delete(), too) and
thus blk_new() (and related functions) no longer take a BB name
argument.

In fact, there is only a single point where blk_new()/blk_new_open() is
called and the new BB is monitor-owned, and that is in blockdev_init().
Besides thus relieving us from having to invent names for all of the BBs
we use in qemu-img, this fixes a bug where qemu cannot create a new
image if there already is a monitor-owned BB named "image".

If a BB and its BDS tree are created in a single operation, as of this
patch the BDS tree will be created before the BB is given a name
(whereas it was the other way around before). This results in minor
change to the output of iotest 087, whose reference output is amended
accordingly.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 15:47:56 +01:00
Max Reitz be4b67bc7d blockdev: Allow creation of BDS trees without BB
If the "id" field is missing from the options given to blockdev-add,
just omit the BlockBackend and create the BlockDriverState tree alone.

However, if "id" is missing, "node-name" must be specified; otherwise,
the BDS tree would no longer be accessible.

Many BDS options which are not parsed by bdrv_open() (like caching)
cannot be specified for these BB-less BDS trees yet. A future patch will
remove this limitation.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-10-23 18:18:22 +02:00
Bo Tu 2711fd33a4 qemu-iotests: disable default qemu devices for cross-platform compatibility
This patch fixes an io test suite issue that was introduced with the
commit c88930a686 'qemu-char: Permit only
a single "stdio" character device'. The option supresses the creation of
default devices such as the floopy and cdrom. Output files for test case
067, 071, 081 and 087 need to be updated to accommodate this change.
Use virtio-blk instead of virtio-blk-pci as the device driver for test
case 067. For virtio-blk-pci is the same with virtio-blk as device
driver but other platform such as s390 may not recognize the virtio-blk-pci.

The default devices differ across machines. As the qemu output often
contains these devices (or events for them, like opening a CD tray on
reset), the reference output currently is rather machine-specific.

All existing qemu tests explicitly configure the devices they're working
with, so just pass -nodefaults to qemu by default to disable the default
devices. Update the reference outputs accordingly.

Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: Xiao Guang Chen <chenxg@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-09-04 20:59:48 +02:00
Markus Armbruster a1f688f415 block: Deprecate QCOW/QCOW2 encryption
We've steered users away from QCOW/QCOW2 encryption for a while,
because it's a flawed design (commit 136cd19 Describe flaws in
qcow/qcow2 encryption in the docs).

In addition to flawed crypto, we have comically bad usability, and
plain old bugs.  Let me show you.

= Example images =

I'm going to use a raw image as backing file, and two QCOW2 images,
one encrypted, and one not:

    $ qemu-img create -f raw backing.img 4m
    Formatting 'backing.img', fmt=raw size=4194304
    $ qemu-img create -f qcow2 -o encryption,backing_file=backing.img,backing_fmt=raw geheim.qcow2 4m
    Formatting 'geheim.qcow2', fmt=qcow2 size=4194304 backing_file='backing.img' backing_fmt='raw' encryption=on cluster_size=65536 lazy_refcounts=off
    $ qemu-img create -f qcow2 -o backing_file=backing.img,backing_fmt=raw normal.qcow2 4m
    Formatting 'normal.qcow2', fmt=qcow2 size=4194304 backing_file='backing.img' backing_fmt='raw' encryption=off cluster_size=65536 lazy_refcounts=off

= Usability issues =

== Confusing startup ==

When no image is encrypted, and you don't give -S, QEMU starts the
guest immediately:

    $ qemu-system-x86_64 -nodefaults -display none -monitor stdio normal.qcow2
    QEMU 2.2.50 monitor - type 'help' for more information
    (qemu) info status
    VM status: running

But as soon as there's an encrypted image in play, the guest is *not*
started, with no notification whatsoever:

    $ qemu-system-x86_64 -nodefaults -display none -monitor stdio geheim.qcow2
    QEMU 2.2.50 monitor - type 'help' for more information
    (qemu) info status
    VM status: paused (prelaunch)

If the user figured out that he needs to type "cont" to enter his
keys, the confusion enters the next level: "cont" asks for at most
*one* key.  If more are needed, it then silently does nothing.  The
user has to type "cont" once per encrypted image:

    $ qemu-system-x86_64 -nodefaults -display none -monitor stdio -drive if=none,file=geheim.qcow2 -drive if=none,file=geheim.qcow2
    QEMU 2.2.50 monitor - type 'help' for more information
    (qemu) info status
    VM status: paused (prelaunch)
    (qemu) c
    none0 (geheim.qcow2) is encrypted.
    Password: ******
    (qemu) info status
    VM status: paused (prelaunch)
    (qemu) c
    none1 (geheim.qcow2) is encrypted.
    Password: ******
    (qemu) info status
    VM status: running

== Incorrect passwords not caught ==

All existing encryption schemes give you the GIGO treatment: garbage
password in, garbage data out.  Guests usually refuse to mount
garbage, but other usage is prone to data loss.

== Need to stop the guest to add an encrypted image ==

    $ qemu-system-x86_64 -nodefaults -display none -monitor stdio
    QEMU 2.2.50 monitor - type 'help' for more information
    (qemu) info status
    VM status: running
    (qemu) drive_add "" if=none,file=geheim.qcow2
    Guest must be stopped for opening of encrypted image
    (qemu) stop
    (qemu) drive_add "" if=none,file=geheim.qcow2
    OK

Commit c3adb58 added this restriction.  Before, we could expose images
lacking an encryption key to guests, with potentially catastrophic
results.  See also "Use without key is not always caught".

= Bugs =

== Use without key is not always caught ==

Encrypted images can be in an intermediate state "opened, but no key".
The weird startup behavior and the need to stop the guest are there to
ensure the guest isn't exposed to that state.  But other things still
are!

* drive_backup

    $ qemu-system-x86_64 -nodefaults -display none -monitor stdio geheim.qcow2
    QEMU 2.2.50 monitor - type 'help' for more information
    (qemu) drive_backup -f ide0-hd0 out.img raw
    Formatting 'out.img', fmt=raw size=4194304

  I guess this writes encrypted data to raw image out.img.  Good luck
  with figuring out how to decrypt that again.

* commit

    $ qemu-system-x86_64 -nodefaults -display none -monitor stdio geheim.qcow2
    QEMU 2.2.50 monitor - type 'help' for more information
    (qemu) commit ide0-hd0

  I guess this writes encrypted data into the unencrypted raw backing
  image, effectively destroying it.

== QMP device_add of usb-storage fails when it shouldn't ==

When the image is encrypted, device_add creates the device, defers
actually attaching it to when the key becomes available, then fails.
This is wrong.  device_add must either create the device and succeed,
or do nothing and fail.

    $ qemu-system-x86_64 -nodefaults -display none -usb -qmp stdio -drive if=none,id=foo,file=geheim.qcow2
    {"QMP": {"version": {"qemu": {"micro": 50, "minor": 2, "major": 2}, "package": ""}, "capabilities": []}}
    { "execute": "qmp_capabilities" }
    {"return": {}}
    { "execute": "device_add", "arguments": { "driver": "usb-storage", "id": "bar", "drive": "foo" } }
    {"error": {"class": "DeviceEncrypted", "desc": "'foo' (geheim.qcow2) is encrypted"}}
    {"execute":"device_del","arguments": { "id": "bar" } }
    {"timestamp": {"seconds": 1426003440, "microseconds": 237181}, "event": "DEVICE_DELETED", "data": {"path": "/machine/peripheral/bar/bar.0/legacy[0]"}}
    {"timestamp": {"seconds": 1426003440, "microseconds": 238231}, "event": "DEVICE_DELETED", "data": {"device": "bar", "path": "/machine/peripheral/bar"}}
    {"return": {}}

This stuff is worse than useless, it's a trap for users.

If people become sufficiently interested in encrypted images to
contribute a cryptographically sane implementation for QCOW2 (or
whatever other format), then rewriting the necessary support around it
from scratch will likely be easier and yield better results than
fixing up the existing mess.

Let's deprecate the mess now, drop it after a grace period, and move
on.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-03-16 17:07:25 +01:00
Max Reitz e4342ce5a2 blockdev: Use blk_new_open() in blockdev_init()
Due to different error propagation, this breaks tests 051 and 087; fix
their output.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1423162705-32065-6-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-02-16 15:07:18 +00:00
Max Reitz 4dd7b8d30c iotests: Filter out "I/O thread spun..." warning
Filter out the "main loop: WARNING: I/O thread spun for..." warning from
qemu output (it hardly matters for code specifically testing I/O).

Furthermore, use _filter_qemu in all the custom functions which run
qemu.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-01-13 11:47:56 +00:00
Fam Zheng 7486458c33 qemu-iotests: Remove traling whitespaces in *.out
This is simply:

  $ cd tests/qemu-iotests; sed -i -e 's/ *$//' *.out

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1418110684-19528-2-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-12-12 16:52:33 +00:00
Peter Maydell b60a7726cc Merge remote-tracking branch 'remotes/qmp-unstable/queue/qmp' into staging
* remotes/qmp-unstable/queue/qmp:
  Add HMP command "info memory-devices"
  qemu-socket: Eliminate silly QERR_ macros
  qemu-socket: Polish errors for connect() and listen() failure
  qemu-iotests: Test missing "driver" key for blockdev-add
  tests: add QMP input visitor test for unions with no discriminator
  qapi: dealloc visitor, implement visit_start_union
  qapi: add visit_start_union and visit_end_union
  virtio-balloon: fix integer overflow in memory stats feature
  monitor: Reset HMP mon->rs in CHR_EVENT_OPEN

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2014-09-29 18:18:29 +01:00
Fam Zheng fe509ee237 qemu-iotests: Test missing "driver" key for blockdev-add
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-09-26 13:14:11 -04:00
Markus Armbruster d224469d87 block: Improve message for device name clashing with node name
Suggested-by: Benoit Canet <benoit.canet@nodalink.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-25 15:24:14 +02:00
Kevin Wolf 90d9d30152 qemu-iotests: Check common namespace for id and node-name
A name that is taken by an ID can't be taken by a node-name at the same
time. Check that conflicts are correctly detected.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2014-04-22 12:12:30 +02:00
Kevin Wolf f2d953ec31 block: Catch duplicate IDs in bdrv_new()
Since commit f298d071, block devices added with blockdev-add don't have
a QemuOpts around in dinfo->opts. Consequently, we can't rely any more
on QemuOpts catching duplicate IDs for block devices.

This patch adds a new check for duplicate IDs to bdrv_new(), and moves
the existing check that the ID isn't already taken for a node-name there
as well.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2014-04-22 12:00:28 +02:00
Markus Armbruster c3adb58fe0 blockdev: Refuse to open encrypted image unless paused
Opening an encrypted image takes an additional step: setting the key.
Between open and the key set, the image must not be used.

We have some protection against accidental use in place: you can't
unpause a guest while we're missing keys.  You can, however, hot-plug
block devices lacking keys into a running guest just fine, or insert
media lacking keys.  In the latter case, notifying the guest of the
insert is delayed until the key is set, which may suffice to protect
at least some guests in common usage.

This patch makes the protection apply in more cases, in a rather
heavy-handed way: it doesn't let you open encrypted images unless
we're in a paused state.

It doesn't extend the protection to users other than the guest (block
jobs?).  Use of runstate_check() from block.c is disgusting.  Best I
can do right now.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-14 16:24:42 +01:00
Kevin Wolf c75203c8d3 qemu-iotests: Test a few blockdev-add error cases
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
2014-03-06 17:28:24 +01:00