Commit Graph
1128 Commits
Author SHA1 Message Date
Peter Maydell 2499453eb1 Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging
Block layer patches:

- qemu-img create: Fail gracefully when backing file is an empty string
- Fixes related to filter block nodes ("Deal with filters" series)
- block/nvme: Various cleanups required to use multiple queues
- block/nvme: Use NvmeBar structure from "block/nvme.h"
- file-win32: Fix "locking" option
- iotests: Allow running from different directory

# gpg: Signature made Thu 10 Sep 2020 10:11:19 BST
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (65 commits)
  block/qcow2-cluster: Add missing "fallthrough" annotation
  block/nvme: Pair doorbell registers
  block/nvme: Use generic NvmeBar structure
  block/nvme: Group controller registers in NVMeRegs structure
  file-win32: Fix "locking" option
  iotests: Allow running from different directory
  iotests: Test committing to overridden backing
  iotests: Add test for commit in sub directory
  iotests: Add filter mirror test cases
  iotests: Add filter commit test cases
  iotests: Let complete_and_wait() work with commit
  iotests: Test that qcow2's data-file is flushed
  block: Leave BDS.backing_{file,format} constant
  block: Inline bdrv_co_block_status_from_*()
  blockdev: Fix active commit choice
  block: Drop backing_bs()
  qemu-img: Use child access functions
  nbd: Use CAF when looking for dirty bitmap
  commit: Deal with filters
  backup: Deal with filters
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-09-11 14:47:49 +01:00
Peter MaydellandMarkus Armbruster 6b306786ca qapi/block-core.json: Fix nbd-server-start docs
Commit eed8b69178 added some new text to the nbd-server-start
documentation in the wrong place.  Since this is after the 'Returns:'
line it's parsed as if it were part of the documentation of the
"Returns:' information.  Move it up to join the rest of the
"documentation of the type as a whole" doc text.

This doesn't look odd in the current HTML rendering, but the
new QAPI-to-rST handling will complain about the indent level
of the lines not matching up with the 'Returns:' line.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200810195019.25427-4-peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-07 17:13:30 +02:00
Peter MaydellandMarkus Armbruster b2f1c13c31 qapi: Fix indentation, again
In commit 26ec4e53f2 and similar commits we fixed the indentation
for doc comments in our qapi json files to follow a new stricter
standard for indentation, which permits only:
    @arg: description line 1
          description line 2

or:
    @arg:
    line 1
    line 2

Unfortunately since we didn't manage to get the script changes that
enforced the new style in, a variety of commits (eg df4097aeaf,
2e44570321) introduced new doc text which doesn't follow the new
stricter rules for indentation on multi-line doc comments.  Bring
those into line with the new rules.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200810195019.25427-3-peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-07 17:13:19 +02:00
Peter MaydellandMarkus Armbruster 76dd0f8497 qapi/migration.json: Fix indentation
Commits 6a9ad15420 and 9004db48c0 added some
new text to qapi/migration.json which doesn't fit the stricter
indentation requirements imposed by the rST documentation generator.
Reindent those lines to the new standard.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200810195019.25427-2-peter.maydell@linaro.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-07 17:12:39 +02:00
Max ReitzandKevin Wolf 05ea385afd blockdev: Fix active commit choice
We have to perform an active commit whenever the top node has a parent
that has taken the WRITE permission on it.

This means that block-commit's @backing-file parameter is no longer
allowed for such nodes, and that users will have to issue a
block-job-complete command.  Neither should pose a problem in practice,
because this case was basically just broken until now.

(Since this commit already touches block-commit's documentation, it also
moves up the chunk explaining general block-commit behavior that for
some reason was situated under @backing-file.)

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Max ReitzandKevin Wolf 3f072a7fb7 mirror: Deal with filters
This includes some permission limiting (for example, we only need to
take the RESIZE permission for active commits where the base is smaller
than the top).

base_overlay is introduced so we can query bdrv_is_allocated_above() on
it - we cannot do that with base itself, because a filter's block_status
is the same as its child node, so if there are filters on base,
bdrv_is_allocated_above() on base would return information including
base.

Use this opportunity to rename qmp_drive_mirror()'s "source" BDS to
"target_backing_bs", because that is what it really refers to.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Max ReitzandKevin Wolf 67acfd2188 stream: Deal with filters
Because of the (not so recent anymore) changes that make the stream job
independent of the base node and instead track the node above it, we
have to split that "bottom" node into two cases: The bottom COW node,
and the node directly above the base node (which may be an R/W filter
or the bottom COW node).

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Markus Armbruster 382bd1cbbd qapi: Document event VSERPORT_CHANGE is rate-limited
Commit e2ae6159de "virtio-serial: report frontend connection state via
monitor" neglected to document the new event is rate-limited.  Fix
that.

Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200806081147.3123652-3-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2020-09-03 09:58:26 +02:00
Kashyap ChamarthyandMarkus Armbruster e947e9c801 qapi/block-core.json: Remove stale description of 'blockdev-add'
On a 'qemu-discuss' thread[1], Kevin identifies that the current doc
blurb for @blockdev-add is stale:

    This is actually a documentation bug. @id doesn't exist,
    blockdev-add never creates a BlockBackend. This was different in the
    very first versions of the patches to add blockdev-add and we
    probably just forgot to update the documentation after removing it.

So remove the stale bits.

And the requirement for 'node-name' is already mentioned in the
documentation of @BlockdevOptions:

    [...]
    # @node-name: the node name of the new node (Since 2.0).
    #             This option is required on the top level of blockdev-add.
    #             Valid node names start with an alphabetic character and may
    #             contain only alphanumeric characters, '-', '.' and '_'. Their
    #             maximum length is 31 characters.
    [...]

[1] https://lists.nongnu.org/archive/html/qemu-discuss/2020-07/msg00071.html
    -- equivalent to "-drive if=ide,id=disk0....."

Fixes: be4b67bc7d ("blockdev: Allow creation of BDS trees without BB")

Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com>
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200805100158.1239390-1-kchamart@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-03 09:41:36 +02:00
Alberto GarciaandMax Reitz 7be2025258 qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bit
Now that the implementation of subclusters is complete we can finally
add the necessary options to create and read images with this feature,
which we call "extended L2 entries".

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <6476caaa73216bd05b7bb2d504a20415e1665176.1594396418.git.berto@igalia.com>
[mreitz: %s/5\.1/5.2/; fixed 302's and 303's reference output]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 09:19:55 +02:00
Peter Maydell 66e01f1cdc Merge remote-tracking branch 'remotes/ericb/tags/pull-bitmaps-2020-08-21' into staging
bitmaps patches for 2020-08-21

- Andrey Shinkevich: Enhance qcow2.py for iotest inspection of qcow2 images
- Max Reitz: Add block-bitmap-mapping migration parameter

# gpg: Signature made Fri 21 Aug 2020 15:05:07 BST
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-bitmaps-2020-08-21:
  iotests: Test node/bitmap aliases during migration
  iotests.py: Let wait_migration() return on failure
  migration: Add block-bitmap-mapping parameter
  iotests: dump QCOW2 header in JSON in #303
  qcow2_format.py: support dumping metadata in JSON format
  qcow2_format.py: collect fields to dump in JSON format
  qcow2.py: Introduce '-j' key to dump in JSON format
  qcow2_format.py: Dump bitmap table serialized entries
  qcow2_format.py: pass cluster size to substructures
  qcow2_format.py: Dump bitmap directory information
  qcow2_format.py: dump bitmap flags in human readable way.
  qcow2_format.py: change Qcow2BitmapExt initialization method
  qcow2_format.py: make printable data an extension class member
  iotests: add test for QCOW2 header dump

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-08-22 19:57:23 +01:00
Peter Maydell ca489cd037 Merge remote-tracking branch 'remotes/ehabkost/tags/machine-next-pull-request' into staging
Machine queue 2020-08-19

Regular post-release changes:
* hw: add compat machines for 5.2 (Cornelia Huck)

Features:
* qmp: Expose MachineClass::default_ram_id
  (Michal Privoznik)

Cleanups:
* qdev: Document qdev_prop_set_drive_err() return value
  (Philippe Mathieu-Daudé)

# gpg: Signature made Wed 19 Aug 2020 16:21:55 BST
# gpg:                using RSA key 5A322FD5ABC4D3DBACCFD1AA2807936F984DC5A6
# gpg:                issuer "ehabkost@redhat.com"
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>" [full]
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost/tags/machine-next-pull-request:
  hw: add compat machines for 5.2
  qmp: Expose MachineClass::default_ram_id
  qdev: Document qdev_prop_set_drive_err() return value

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-08-22 14:37:31 +01:00
Max ReitzandEric Blake 31e4c354b3 migration: Add block-bitmap-mapping parameter
This migration parameter allows mapping block node names and bitmap
names to aliases for the purpose of block dirty bitmap migration.

This way, management tools can use different node and bitmap names on
the source and destination and pass the mapping of how bitmaps are to be
transferred to qemu (on the source, the destination, or even both with
arbitrary aliases in the migration stream).

While touching this code, fix a bug where bitmap names longer than 255
bytes would fail an assertion in qemu_put_counted_string().

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200820150725.68687-2-mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-08-21 08:56:09 -05:00
Marc-André LureauandPaolo Bonzini 5242523b5f meson: convert qapi-specific to meson
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:24 -04:00
Paolo Bonzini a81df1b68b libqemuutil, qapi, trace: convert to meson
This shows how to do some "computations" in meson.build using its array
and dictionary data structures, and also a basic usage of the sourceset
module for conditional compilation.

Notice the new "if have_system" part of util/meson.build, which fixes
a bug in the old build system was buggy: util/dbus.c was built even for
non-softmmu builds, but the dependency on -lgio was lost when the linking
was done through libqemuutil.a.  Because all of its users required gio
otherwise, the bug was hidden.  Meson instead propagates libqemuutil's
dependencies down to its users, and shows the problem.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:08 -04:00
Paolo Bonzini 243af0225a trace: switch position of headers to what Meson requires
Meson doesn't enjoy the same flexibility we have with Make in choosing
the include path.  In particular the tracing headers are using
$(build_root)/$(<D).

In order to keep the include directives unchanged,
the simplest solution is to generate headers with patterns like
"trace/trace-audio.h" and place forwarding headers in the source tree
such that for example "audio/trace.h" includes "trace/trace-audio.h".

This patch is too ugly to be applied to the Makefiles now.  It's only
a way to separate the changes to the tracing header files from the
Meson rewrite of the tracing logic.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:18:24 -04:00
Michal PrivoznikandEduardo Habkost c556600598 qmp: Expose MachineClass::default_ram_id
If a management application (like Libvirt) want's to preserve
migration ability and switch to '-machine memory-backend' it
needs to set exactly the same RAM id as QEMU would. Since the id
is machine type dependant, expose it under 'query-machines'
result. Some machine types don't have the attribute set (riscv
family for example), therefore the QMP attribute must be
optional.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Message-Id: <9384422f63fe594a54d801f9cb4539b1d2ce9b67.1590481402.git.mprivozn@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
[ehabkost: updated doc to "since 5.2"]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-08-19 10:45:21 -04:00
Andrea BolognaniandMarkus Armbruster f7160f3218 schemas: Add vim modeline
The various schemas included in QEMU use a JSON-based format which
is, however, strictly speaking not valid JSON.

As a consequence, when vim tries to apply syntax highlight rules
for JSON (as guessed from the file name), the result is an unreadable
mess which mostly consist of red markers pointing out supposed errors
in, well, pretty much everything.

Using Python syntax highlighting produces much better results, and
in fact these files already start with specially-formatted comments
that instruct Emacs to process them as if they were Python files.

This commit adds the equivalent special comments for vim.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Message-Id: <20200729185024.121766-1-abologna@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-08-03 08:28:08 +02:00
Markus Armbruster fbeed19761 qapi: Delete unwanted indentation of top-level expressions
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200730091656.2633334-1-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[One more line de-indented]
2020-08-03 08:28:08 +02:00
Peter MaydellandMarkus Armbruster 6ac3f1e799 qapi/machine.json: Fix missing newline in doc comment
In commit 176d2cda0d we added the @die-id field
to the CpuInstanceProperties struct, but in the process
accidentally removed the newline between the doc-comment
lines for @core-id and @thread-id.

Put the newline back in; this fixes a misformatting in the
generated HTML QMP reference manual.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200729191019.19168-1-peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-08-03 08:28:08 +02:00
Marc-André LureauandKevin Wolf a08464521c Remove VXHS block device
The vxhs code doesn't compile since v2.12.0. There's no point in fixing
and then adding CI for a config that our users have demonstrated that
they do not use; better to just remove it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200711065926.2204721-1-marcandre.lureau@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-17 14:20:57 +02:00
Kevin Wolf ffa244c84a file-posix: Mitigate file fragmentation with extent size hints
Especially when O_DIRECT is used with image files so that the page cache
indirection can't cause a merge of allocating requests, the file will
fragment on the file system layer, with a potentially very small
fragment size (this depends on the requests the guest sent).

On Linux, fragmentation can be reduced by setting an extent size hint
when creating the file (at least on XFS, it can't be set any more after
the first extent has been allocated), basically giving raw files a
"cluster size" for allocation.

This adds a create option to set the extent size hint, and changes the
default from not setting a hint to setting it to 1 MB. The main reason
why qcow2 defaults to smaller cluster sizes is that COW becomes more
expensive, which is not an issue with raw files, so we can choose a
larger size. The tradeoff here is only potentially wasted disk space.

For qcow2 (or other image formats) over file-posix, the advantage should
even be greater because they grow sequentially without leaving holes, so
there won't be wasted space. Setting even larger extent size hints for
such images may make sense. This can be done with the new option, but
let's keep the default conservative for now.

The effect is very visible with a test that intentionally creates a
badly fragmented file with qemu-img bench (the time difference while
creating the file is already remarkable) and then looks at the number of
extents and the time a simple "qemu-img map" takes.

Without an extent size hint:

    $ ./qemu-img create -f raw -o extent_size_hint=0 ~/tmp/test.raw 10G
    Formatting '/home/kwolf/tmp/test.raw', fmt=raw size=10737418240 extent_size_hint=0
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 0
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 0, step size 8192)
    Run completed in 25.848 seconds.
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 4096
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 4096, step size 8192)
    Run completed in 19.616 seconds.
    $ filefrag ~/tmp/test.raw
    /home/kwolf/tmp/test.raw: 2000000 extents found
    $ time ./qemu-img map ~/tmp/test.raw
    Offset          Length          Mapped to       File
    0               0x1e8480000     0               /home/kwolf/tmp/test.raw

    real    0m1,279s
    user    0m0,043s
    sys     0m1,226s

With the new default extent size hint of 1 MB:

    $ ./qemu-img create -f raw -o extent_size_hint=1M ~/tmp/test.raw 10G
    Formatting '/home/kwolf/tmp/test.raw', fmt=raw size=10737418240 extent_size_hint=1048576
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 0
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 0, step size 8192)
    Run completed in 11.833 seconds.
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 4096
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 4096, step size 8192)
    Run completed in 10.155 seconds.
    $ filefrag ~/tmp/test.raw
    /home/kwolf/tmp/test.raw: 178 extents found
    $ time ./qemu-img map ~/tmp/test.raw
    Offset          Length          Mapped to       File
    0               0x1e8480000     0               /home/kwolf/tmp/test.raw

    real    0m0,061s
    user    0m0,040s
    sys     0m0,014s

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200707142329.48303-1-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Michael RolnikandPhilippe Mathieu-Daudé 42f3ff0013 target/avr: Register AVR support with the rest of QEMU
Add AVR related definitions into QEMU, make AVR support buildable.

[AM: Remove word 'Atmel' from filenames and all elements of code]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-23-huth@tuxfamily.org>
[PMD: Fixed @avr tag in qapi/machine.json]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2020-07-11 11:02:05 +02:00
Markus Armbruster 7b3cb8037c qapi: Purge error_propagate() from QAPI core
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-42-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster 668f62ec62 error: Eliminate error_propagate() with Coccinelle, part 1
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  Convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
        return ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
        return ...
    }

where nothing else needs @err.  Coccinelle script:

    @rule1 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
         if (
    (
    -        fun(args, &err, args2)
    +        fun(args, errp, args2)
    |
    -        !fun(args, &err, args2)
    +        !fun(args, errp, args2)
    |
    -        fun(args, &err, args2) op c1
    +        fun(args, errp, args2) op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    )
         }

    @rule2 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    expression var;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
    -    var = fun(args, &err, args2);
    +    var = fun(args, errp, args2);
         ... when != err
         if (
    (
             var
    |
             !var
    |
             var op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    |
             return var;
    )
         }

    @depends on rule1 || rule2@
    identifier err;
    @@
    -    Error *err = NULL;
         ... when != err

Not exactly elegant, I'm afraid.

The "when != lbl:" is necessary to avoid transforming

         if (fun(args, &err)) {
             goto out
         }
         ...
     out:
         error_propagate(errp, err);

even though other paths to label out still need the error_propagate().
For an actual example, see sclp_realize().

Without the "when strict", Coccinelle transforms vfio_msix_setup(),
incorrectly.  I don't know what exactly "when strict" does, only that
it helps here.

The match of return is narrower than what I want, but I can't figure
out how to express "return where the operand doesn't use @err".  For
an example where it's too narrow, see vfio_intx_enable().

Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
confused by ARMSSE being used both as typedef and function-like macro
there.  Converted manually.

Line breaks tidied up manually.  One nested declaration of @local_err
deleted manually.  Preexisting unwanted blank line dropped in
hw/riscv/sifive_e.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-10 15:18:08 +02:00