Set (and clear) histograms through new command
block-latency-histogram-set and show new statistics in
query-blockstats results.

For now, the command is marked experimental with prefix 'x-',
to gain experience with the interface without being stuck
with design decisions.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180309165212.97144-3-vsementsov@virtuozzo.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
[eblake: fix typos, mention x- prefix in commit message]
Signed-off-by: NEric Blake <eblake@redhat.com>

Introduce latency histogram statics for block devices.
For each accounted operation type, the latency region [0, +inf) is
divided into subregions by several points. Then, calculate
hits for each subregion.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180309165212.97144-2-vsementsov@virtuozzo.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Test the new OOB capability.  Here we used the new "x-oob-test" command.
First, we send a lock=true and oob=false command to hang the main
thread.  Then send another lock=false and oob=true command (which will
be run inside parser this time) to free that hanged command.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-24-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: grammar tweaks]
Signed-off-by: NEric Blake <eblake@redhat.com>

OOB introduced DROP event for flow control.  This should not affect old
QMP clients.  Add a command batching check to make sure of it.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-23-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

This command is only used to test OOB functionality.  It should not be
used for any other purposes.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-22-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: grammar tweak]
Signed-off-by: NEric Blake <eblake@redhat.com>

Start to use dedicate IO thread for QMP monitors that are not using
MUXed chardev.
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-21-peterx@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

For those monitors who have enabled IO thread, we'll offload the
responding procedure into IO thread.  The main reason is that chardev is
not thread safe, and we need to do all the read/write IOs in the same
thread.  For use_io_thr=true monitors, that thread is the IO thread.

We do this isolation in similar pattern as what we have done to the
request queue: we first create one response queue for each monitor, then
instead of replying directly in the main thread, we queue the responses
and kick the IO thread to do the rest of the job for us.

A funny thing after doing this is that, when the QMP clients send "quit"
to QEMU, it's possible that we close the IOThread even earlier than
replying to that "quit".  So another thing we need to do before cleaning
up the monitors is that we need to flush the response queue (we don't
need to do that for command queue; after all we are quitting) to make
sure replies for handled commands are always flushed back to clients.
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-20-peterx@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Having "allow-oob":true for a command does not mean that this command
will always be run in out-of-band mode.  The out-of-band quick path will
only be executed if we specify the extra "run-oob" flag when sending the
QMP request:

    { "execute":   "command-that-allows-oob",
      "arguments": { ... },
      "control":   { "run-oob": true } }

The "control" key is introduced to store this extra flag.  "control"
field is used to store arguments that are shared by all the commands,
rather than command specific arguments.  Let "run-oob" be the first.

Note that in the patch I exported qmp_dispatch_check_obj() to be used to
check the request earlier, and at the same time allowed "id" field to be
there since actually we always allow that.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-19-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: rebase to qobject_to(), spelling fix]
Signed-off-by: NEric Blake <eblake@redhat.com>

Here "oob" stands for "Out-Of-Band".  When "allow-oob" is set, it means
the command allows out-of-band execution.

The "oob" idea is proposed by Markus Armbruster in following thread:

  https://lists.gnu.org/archive/html/qemu-devel/2017-09/msg02057.html

This new "allow-oob" boolean will be exposed by "query-qmp-schema" as
well for command entries, so that QMP clients can know which commands
can be used in out-of-band calls. For example the command "migrate"
originally looks like:

  {"name": "migrate", "ret-type": "17", "meta-type": "command",
   "arg-type": "86"}

And it'll be changed into:

  {"name": "migrate", "ret-type": "17", "allow-oob": false,
   "meta-type": "command", "arg-type": "86"}

This patch only provides the QMP interface level changes.  It does not
contain the real out-of-band execution implementation yet.
Suggested-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-18-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: rebase on introspection done by qlit]
Signed-off-by: NEric Blake <eblake@redhat.com>

Set maximum QMP command queue length to 8.  If the queue is full,
instead of queuing the command, we directly return a "command-dropped"
event, telling the client that a specific command is dropped.

Note that this flow control mechanism is only valid if OOB is enabled.
If it's not, the effective queue length will always be 1, which strictly
follows original behavior of QMP command handling (which never drops
messages).
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-17-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: commit message grammar, abort on failure to send event]
Signed-off-by: NEric Blake <eblake@redhat.com>

This event will be emitted if one QMP command is dropped.  Also,
declare an enum for the reasons.
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-16-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: rebase to master]
Signed-off-by: NEric Blake <eblake@redhat.com>

Originally QMP goes through these steps:

  JSON Parser --> QMP Dispatcher --> Respond
      /|\    (2)                (3)     |
   (1) |                               \|/ (4)
       +---------  main thread  --------+

This patch does this:

  JSON Parser     QMP Dispatcher --> Respond
      /|\ |           /|\       (4)     |
       |  | (2)        | (3)            |  (5)
   (1) |  +----->      |               \|/
       +---------  main thread  <-------+

So the parsing job and the dispatching job is isolated now.  It gives us
a chance in follow up patches to totally move the parser outside.

The isolation is done using one QEMUBH. Only one dispatcher QEMUBH is
used for all the monitors.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-15-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: grammar tweaks, rebase to qobject_to()]
Signed-off-by: NEric Blake <eblake@redhat.com>

This patches allows QMP monitors to be suspended/resumed.

One thing to mention is that for QMPs that are using IOThreads, we need
an explicit kick for the IOThread in case it is sleeping.

Meanwhile, we need to take special care on non-interactive HMPs.
Currently only gdbserver is using that.  For these monitors, we still
don't allow suspend/resume operations.

Since at it, add traces for the operations.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-14-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Monitor code now can be run in more than one thread.  Let it be thread
safe when accessing suspend_cnt counter.
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-13-peterx@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

A tiny refactoring, preparing to split the QMP dispatcher away.
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-12-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: rebase to qobject_to() usage]
Signed-off-by: NEric Blake <eblake@redhat.com>

There were no QMP capabilities defined.  Define the first capability,
"oob", to allow out-of-band messages.

After this patch, we will allow QMP clients to enable QMP capabilities
when sending the first "qmp_capabilities" command.  Originally we are
starting QMP session with no arguments like:

  { "execute": "qmp_capabilities" }

Now we can enable some QMP capabilities using (take OOB as example,
which is the only capability that we support):

  { "execute": "qmp_capabilities",
    "arguments": { "enable": [ "oob" ] } }

When the "arguments" key is not provided, no capability is enabled.

For capability "oob", the monitor needs to be run on a dedicated IO
thread, otherwise the command will fail.  For example, trying to enable
OOB on a MUXed typed QMP monitor will fail.

One thing to mention is that QMP capabilities are per-monitor, and also
when the connection is closed due to some reason, the capabilities will
be reset.

Also, touch up qmp-test.c to test the new bits.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-11-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: touch up commit message]
Signed-off-by: NEric Blake <eblake@redhat.com>

For each Monitor, add one field "use_io_thr" to show whether it will be
using the dedicated monitor IO thread to handle input/output.  When set,
monitor IO parsing work will be offloaded to the dedicated monitor IO
thread, rather than the original main loop thread.

This only works for QMP.  HMP will always be run on the main loop
thread.

Currently we're still keeping use_io_thr off always.  Will turn it on
later at some point.

One thing to mention is that we cannot set use_io_thr for every QMP
monitor.  The problem is that MUXed typed chardevs may not work well
with it now. When MUX is used, frontend of chardev can be the monitor
plus something else.  The only thing we know would be safe to be run
outside main thread so far is the monitor frontend. All the rest of the
frontends should still be run in main thread only.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-10-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: squash in Peter's followup patch to avoid test failures]
Signed-off-by: NEric Blake <eblake@redhat.com>

It was QLIST.  I want to use this list to do monitor priority job later,
which need tail insertion ability.  So switching to a tail queue.
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-9-peterx@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

There are many places where the monitor initializes its globals:

- monitor_init_qmp_commands() at the very beginning
- single function to init monitor_lock
- in the first entry of monitor_init() using "is_first_init"

Unify them a bit.

monitor_lock is not used before monitor_init() (as confirmed by code
analysis and gdb watchpoints); so we are safe delaying what was a
constructor-time initialization of the mutex into the later first call
to monitor_init().
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-8-peterx@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

In monitor_qmp_read(), we have the hack to temporarily replace the
cur_mon pointer.  Now we move this hack deeper inside the QMP dispatcher
routine since the Monitor pointer can be actually obtained using
container_of() upon the parser object, just like most of the other JSON
parser users do.

This does not make much sense as a single patch.  However, this will be
a big step for the next patch, when the QMP dispatcher routine will be
split from the QMP parser.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-7-peterx@redhat.com>
[eblake: rebase context of qobject_to() macro]
Signed-off-by: NEric Blake <eblake@redhat.com>

It's part of the data init.  Collect it.
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-6-peterx@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

We can simplify object_property_get_str() using the new
qobject_get_try_str().
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-5-peterx@redhat.com>
[eblake: rebase context of qobject_to() macro]
Signed-off-by: NEric Blake <eblake@redhat.com>

A quick way to fetch string from qobject when it's a QString.
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-4-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: rebase to qobject_to() macro]
Signed-off-by: NEric Blake <eblake@redhat.com>

The only difference from qstring_get_str() is that it allows the qstring
to be NULL.  If so, NULL is returned.

CC: Eric Blake <eblake@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-3-peterx@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Update both the developer and spec for the new QMP OOB (Out-Of-Band)
command.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-2-peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: grammar tweaks]
Signed-off-by: NEric Blake <eblake@redhat.com>

TLS handshake may create background GSource tasks, while we won't know
the correct GMainContext until the whole chardev (including frontend)
inited.  Let's postpone the initial TLS handshake until machine done.

For dynamically created tcp chardev, we don't postpone that by checking
the init_machine_done variable.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
[peterx: add missing include line, do unit test]
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180308140714.28906-1-peterx@redhat.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

We have a clear replacement, so let's deprecate it.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Message-Id: <20180224154033.29559-8-mreitz@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Instead of converting all "backing": null instances into "backing": "",
handle a null value directly in bdrv_open_inherit().

This enables explicitly null backing links for json:{} filenames.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Message-Id: <20180224154033.29559-7-mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: rebase to qobject_to() parameter order and qapi headers split]
Signed-off-by: NEric Blake <eblake@redhat.com>

This patch reworks some places which use either qobject_type() checks
plus qobject_to(), where the latter alone is sufficient, or NULL checks
plus qobject_type() checks where we can simply do a qobject_to() != NULL
check.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Message-Id: <20180224154033.29559-6-mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: rebase to qobject_to() parameter ordering]
Signed-off-by: NEric Blake <eblake@redhat.com>

They are no longer needed now.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Message-Id: <20180224154033.29559-5-mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

This patch was generated using the following Coccinelle script:

@@
expression Obj;
@@
(
- qobject_to_qnum(Obj)
+ qobject_to(QNum, Obj)
|
- qobject_to_qstring(Obj)
+ qobject_to(QString, Obj)
|
- qobject_to_qdict(Obj)
+ qobject_to(QDict, Obj)
|
- qobject_to_qlist(Obj)
+ qobject_to(QList, Obj)
|
- qobject_to_qbool(Obj)
+ qobject_to(QBool, Obj)
)

and a bit of manual fix-up for overly long lines and three places in
tests/check-qjson.c that Coccinelle did not find.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Message-Id: <20180224154033.29559-4-mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[eblake: swap order from qobject_to(o, X), rebase to master, also a fix
to latent false-positive compiler complaint about hw/i386/acpi-build.c]
Signed-off-by: NEric Blake <eblake@redhat.com>

This is a dynamic casting macro that, given a QObject type, returns an
object as that type or NULL if the object is of a different type (or
NULL itself).

The macro uses lower-case letters because:
1. There does not seem to be a hard rule on whether qemu macros have to
   be upper-cased,
2. The current situation in qapi/qmp is inconsistent (compare e.g.
   QINCREF() vs. qdict_put()),
3. qobject_to() will evaluate its @obj parameter only once, thus it is
   generally not important to the caller whether it is a macro or not,
4. I prefer it aesthetically.

The macro parameter order is chosen with typename first for
consistency with other QAPI macros like QAPI_CLONE(), as well as
for legibility (read it as "qobject to" type "applied to" obj).
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Message-Id: <20180224154033.29559-3-mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
[eblake: swap parameter order to list type first, avoid clang ubsan
warning on QOBJECT(NULL) and container_of(NULL,type,base)]
Signed-off-by: NEric Blake <eblake@redhat.com>

_Static_assert() allows us to specify messages, and that may come in
handy.  Even without _Static_assert(), encouraging developers to put a
helpful message next to the QEMU_BUILD_BUG_* may make debugging easier
whenever it breaks.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Message-Id: <20180224154033.29559-2-mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Replace the generated json string with a literal qobject. The later is
easier to deal with, at run time as well as compile time: adding #if
conditionals will be easier than in a json string.

The output of query-qmp-schema is not changed.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <20180305172951.2150-5-marcandre.lureau@redhat.com>
[eblake: fix python 3 failure]
Signed-off-by: NEric Blake <eblake@redhat.com>

Instantiate a QObject* from a literal QLitObject.

LitObject only supports int64_t for now.  uint64_t and double aren't
implemented.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <20180305172951.2150-4-marcandre.lureau@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Suggested-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <20180305172951.2150-3-marcandre.lureau@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <20180305172951.2150-2-marcandre.lureau@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Block layer patches

# gpg: Signature made Mon 19 Mar 2018 11:01:45 GMT
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (46 commits)
  iotests: Avoid realpath, for CentOS 6
  block: fix iotest 146 output expectations
  iscsi: fix iSER compilation
  block: Fix leak of ignore_children in error path
  vvfat: Fix inherit_options flags
  block/mirror: change the semantic of 'force' of block-job-cancel
  vpc: Require aligned size in .bdrv_co_create
  vpc: Support .bdrv_co_create
  vhdx: Support .bdrv_co_create
  vdi: Make comments consistent with other drivers
  qed: Support .bdrv_co_create
  qcow: Support .bdrv_co_create
  qemu-iotests: Enable write tests for parallels
  parallels: Support .bdrv_co_create
  iotests: Add regression test for commit base locking
  block: Fix flags in reopen queue
  vdi: Implement .bdrv_co_create
  vdi: Move file creation to vdi_co_create_opts
  vdi: Pull option parsing from vdi_co_create
  qemu-iotests: Test luks QMP image creation
  ...
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

CentOS 6 lacks a realpath binary on the base install, which makes
all iotests runs fail since the 2.11 release:

001         - output mismatch (see 001.out.bad)
./check: line 815: realpath: command not found
diff: missing operand after `/home/dummy/qemu/tests/qemu-iotests/001.out'
diff: Try `diff --help' for more information.

Many of the uses of 'realpath' in the check script were being
used on the output of 'type -p' - but that is already an
absolute file name.  While a canonical name can often be
shorter (realpath gets rid of /../), it can also be longer (due
to symlink expansion); and we really don't care if the name is
canonical, merely that it was an executable file with an
absolute path.  These were broken in commit cceaf1db.

The remaining use of realpath was to convert a possibly relative
filename into an absolute one before calling diff to make it
easier to copy-and-paste the filename for moving the .bad file
into place as the new reference file even when running iotests
out-of-tree (see commit 93e53fb6), but $PWD can achieve the same
purpose.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Commit bff55548 added "force_size" into the common.filter for
_filter_img_create(), but test 146 still expects it in the output.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>