Commit graph

27 commits

Author SHA1 Message Date
Philippe Mathieu-Daudé
c7b64948f8 meson: Replace CONFIG_SOFTMMU -> CONFIG_SYSTEM_ONLY
Since we *might* have user emulation with softmmu,
use the clearer 'CONFIG_SYSTEM_ONLY' key to check
for system emulation.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230613133347.82210-9-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-06-20 10:01:30 +02:00
Jonathan Cameron
415442a1b4 hw/mem/cxl_type3: Add CXL RAS Error Injection Support.
CXL uses PCI AER Internal errors to signal to the host that an error has
occurred. The host can then read more detailed status from the CXL RAS
capability.

For uncorrectable errors: support multiple injection in one operation
as this is needed to reliably test multiple header logging support in an
OS. The equivalent feature doesn't exist for correctable errors, so only
one error need be injected at a time.

Note:
 - Header content needs to be manually specified in a fashion that
   matches the specification for what can be in the header for each
   error type.

Injection via QMP:
{ "execute": "qmp_capabilities" }
...
{ "execute": "cxl-inject-uncorrectable-errors",
  "arguments": {
    "path": "/machine/peripheral/cxl-pmem0",
    "errors": [
        {
            "type": "cache-address-parity",
            "header": [ 3, 4]
        },
        {
            "type": "cache-data-parity",
            "header": [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31]
        },
        {
            "type": "internal",
            "header": [ 1, 2, 4]
        }
        ]
  }}
...
{ "execute": "cxl-inject-correctable-error",
    "arguments": {
        "path": "/machine/peripheral/cxl-pmem0",
        "type": "physical"
    } }

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20230302133709.30373-9-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-03-07 12:39:00 -05:00
zhenwei pi
14c9fd1673 cryptodev: Introduce cryptodev.json
Introduce QCryptodevBackendType in cryptodev.json, also apply this to
related codes. Then we can drop 'enum CryptoDevBackendOptionsType'.

Note that `CRYPTODEV_BACKEND_TYPE_NONE` is *NOT* used by anywhere, so
drop it(no 'none' enum in QCryptodevBackendType).

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230301105847.253084-2-pizhenwei@bytedance.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-03-07 12:38:59 -05:00
Thomas Huth
e0091133e3 qga: Allow building of the guest agent without system emulators or tools
If configuring with "--disable-system --disable-user --enable-guest-agent"
the linking currently fails with:

qga/qemu-ga.p/commands.c.o: In function `qmp_command_info':
build/../../home/thuth/devel/qemu/qga/commands.c:70: undefined reference to `qmp_command_name'
build/../../home/thuth/devel/qemu/qga/commands.c:71: undefined reference to `qmp_command_is_enabled'
build/../../home/thuth/devel/qemu/qga/commands.c:72: undefined reference to `qmp_has_success_response'
qga/qemu-ga.p/commands.c.o: In function `qmp_guest_info':
build/../../home/thuth/devel/qemu/qga/commands.c:82: undefined reference to `qmp_for_each_command'
qga/qemu-ga.p/commands.c.o: In function `qmp_guest_exec':
build/../../home/thuth/devel/qemu/qga/commands.c:410: undefined reference to `qbase64_decode'
qga/qemu-ga.p/channel-posix.c.o: In function `ga_channel_open':
build/../../home/thuth/devel/qemu/qga/channel-posix.c:214: undefined reference to `unix_listen'
build/../../home/thuth/devel/qemu/qga/channel-posix.c:228: undefined reference to `socket_parse'
build/../../home/thuth/devel/qemu/qga/channel-posix.c:234: undefined reference to `socket_listen'
qga/qemu-ga.p/commands-posix.c.o: In function `qmp_guest_file_write':
build/../../home/thuth/devel/qemu/qga/commands-posix.c:527: undefined reference to `qbase64_decode'

Let's make sure that we also compile and link the required files if
the system emulators have not been enabled.

Message-Id: <20221110083626.31899-1-thuth@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2022-11-11 09:17:45 +01:00
Laurent Vivier
a5ebce3857 qmp: add QMP command x-query-virtio
This new command lists all the instances of VirtIODevices with
their canonical QOM path and name.

[Jonah: @virtio_list duplicates information that already exists in
 the QOM composition tree. However, extracting necessary information
 from this tree seems to be a bit convoluted.

 Instead, we still create our own list of realized virtio devices
 but use @qmp_qom_get with the device's canonical QOM path to confirm
 that the device exists and is realized. If the device exists but
 is actually not realized, then we remove it from our list (for
 synchronicity to the QOM composition tree).

 Also, the QMP command @x-query-virtio is redundant as @qom-list
 and @qom-get are sufficient to search '/machine/' for realized
 virtio devices. However, @x-query-virtio is much more convenient
 in listing realized virtio devices.]

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1660220684-24909-2-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-09 16:38:45 -04:00
Paolo Bonzini
eccae02d99 meson: remove dead code
Found with "muon analyze".

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-01 07:42:37 +02:00
Mark Kanda
b9f88dc071 qmp: Support for querying stats
Gathering statistics is important for development, for monitoring and
for performance measurement.  There are tools such as kvm_stat that do
this and they rely on the _user_ knowing the interesting data points
rather than the tool (which can treat them as opaque).

The commands introduced in this commit introduce QMP support for
querying stats; the goal is to take the capabilities of these tools
and making them available throughout the whole virtualization stack,
so that one can observe, monitor and measure virtual machines without
having shell access + root on the host that runs them.

query-stats returns a list of all stats per target type (only VM
and vCPU to start); future commits add extra options for specifying
stat names, vCPU qom paths, and providers.  All these are used by the
HMP command "info stats".  Because of the development usecases around
statistics, a good HMP interface is important.

query-stats-schemas returns a list of stats included in each target
type, with an option for specifying the provider.  The concepts in the
schema are based on the KVM binary stats' own introspection data, just
translated to QAPI.

There are two reasons to have a separate schema that is not tied to
the QAPI schema.  The first is the contents of the schemas: the new
introspection data provides different information than the QAPI data,
namely unit of measurement, how the numbers are gathered and change
(peak/instant/cumulative/histogram), and histogram bucket sizes.
There's really no reason to have this kind of metadata in the QAPI
introspection schema (except possibly for the unit of measure, but
there's a very weak justification).

Another reason is the dynamicity of the schema.  The QAPI introspection
data is very much static; and while QOM is somewhat more dynamic,
generally we consider that to be a bug rather than a feature these days.
On the other hand, the statistics that are exposed by QEMU might be
passed through from another source, such as KVM, and the disadvantages of
manually updating the QAPI schema for outweight the benefits from vetting
the statistics and filtering out anything that seems "too unstable".
Running old QEMU with new kernel is a supported usecase; if old QEMU
cannot expose statistics from a new kernel, or if a kernel developer
needs to change QEMU before gathering new info from the new kernel,
then that is a poor user interface.

The framework provides a method to register callbacks for these QMP
commands.  Most of the work in fact is done by the callbacks, and a
large majority of this patch is new QAPI structs and commands.

Examples (with KVM stats):

- Query all VM stats:

{ "execute": "query-stats", "arguments" : { "target": "vm" } }

{ "return": [
     { "provider": "kvm",
       "stats": [
          { "name": "max_mmu_page_hash_collisions", "value": 0 },
          { "name": "max_mmu_rmap_size", "value": 0 },
          { "name": "nx_lpage_splits", "value": 148 },
          ... ] },
     { "provider": "xyz",
       "stats": [ ... ] }
] }

- Query all vCPU stats:

{ "execute": "query-stats", "arguments" : { "target": "vcpu" } }

{ "return": [
     { "provider": "kvm",
       "qom_path": "/machine/unattached/device[0]"
       "stats": [
          { "name": "guest_mode", "value": 0 },
          { "name": "directed_yield_successful", "value": 0 },
          { "name": "directed_yield_attempted", "value": 106 },
          ... ] },
     { "provider": "kvm",
       "qom_path": "/machine/unattached/device[1]"
       "stats": [
          { "name": "guest_mode", "value": 0 },
          { "name": "directed_yield_successful", "value": 0 },
          { "name": "directed_yield_attempted", "value": 106 },
          ... ] },
] }

- Retrieve the schemas:

{ "execute": "query-stats-schemas" }

{ "return": [
    { "provider": "kvm",
      "target": "vcpu",
      "stats": [
         { "name": "guest_mode",
           "unit": "none",
           "base": 10,
           "exponent": 0,
           "type": "instant" },
        { "name": "directed_yield_successful",
           "unit": "none",
           "base": 10,
           "exponent": 0,
           "type": "cumulative" },
        ... ]
    },
    { "provider": "kvm",
      "target": "vm",
      "stats": [
        { "name": "max_mmu_page_hash_collisions",
           "unit": "none",
           "base": 10,
           "exponent": 0,
           "type": "peak" },
        ... ]
    },
    { "provider": "xyz",
      "target": "vm",
      "stats": [ ... ]
    }
] }

Signed-off-by: Mark Kanda <mark.kanda@oracle.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-14 16:50:29 +02:00
Vladimir Sementsov-Ogievskiy
761a1a488e qapi: generate trace events by default
We don't generate trace events for tests/ and qga/ because that it is
not simple and not necessary. We have corresponding comments in both
tests/meson.build and qga/meson.build.

Still to not miss possible future qapi code generation call, and not to
forget to enable trace events generation, let's enable it by default.
So, turn option --gen-trace into opposite --no-trace-events and use new
option only in tests/ and qga/ where we already have good comments why
we don't generate trace events code.

Note that this commit enables trace-events generation for qapi-gen.py
call from tests/qapi-schema/meson.build and storage-daemon/meson.build.
Still, both are kind of noop: tests/qapi-schema/ doesn't seem to
generate any QMP command code and no .trace-events files anyway,
storage-daemon/ uses common QMP command implementations and just
generate empty .trace-events

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220126161130.3240892-8-vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2022-01-27 15:17:35 +01:00
Vladimir Sementsov-Ogievskiy
b83a80e831 meson: generate trace events for qmp commands
1. Use --gen-trace when generate qmp commands
2. Add corresponding .trace-events files as outputs in qapi_files
   custom target
3. Define global qapi_trace_events list of .trace-events file targets,
   to fill in trace/qapi.build and to use in trace/meson.build
4. In trace/meson.build use the new array as an additional source of
   .trace_events files to be processed

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220126161130.3240892-5-vsementsov@virtuozzo.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2022-01-27 11:26:40 +01:00
Daniel P. Berrangé
f9429c6790 monitor: introduce HumanReadableText and HMP support
This provides a foundation on which to convert simple HMP commands to
use QMP. The QMP implementation will generate formatted text targeted
for human consumption, returning it in the HumanReadableText data type.

The HMP command handler will simply print out the formatted string
within the HumanReadableText data type. Since this will be an entirely
formulaic action in the case of HMP commands taking no arguments, a
custom command handler is provided.

Thus instead of registering a 'cmd' callback for the HMP command, a
'cmd_info_hrt' callback is provided, which will simply be a pointer
to the QMP implementation.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2021-11-02 15:55:13 +00:00
Paolo Bonzini
18fa3ebc45 qapi: introduce forwarding visitor
This new adaptor visitor takes a single field of the adaptee, and exposes it
with a different name.

This will be used for QOM alias properties.  Alias targets can of course
have a different name than the alias property itself (e.g. a machine's
pflash0 might be an alias of a property named 'drive').  When the target's
getter or setter invokes the visitor, it will use a different name than
what the caller expects, and the visitor will not be able to find it
(or will consume erroneously).

The solution is for alias getters and setters to wrap the incoming
visitor, and forward the sole field that the target is expecting while
renaming it appropriately.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-23 18:17:17 +02:00
Jason Wang
603f2f7c6c Revert "hmp: Use QAPI NetdevInfo in hmp_info_network"
Several issues has been reported for query-netdev info
series. Consider it's late in the rc, this reverts commit
a0724776c5.

Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-04-08 17:33:59 +08:00
Markus Armbruster
6dd75472d5 qemu-options: New -compat to set policy for deprecated interfaces
New option -compat lets you configure what to do when deprecated
interfaces get used.  This is intended for testing users of the
management interfaces.  It is experimental.

-compat deprecated-input=<input-policy> configures what to do when
deprecated input is received.  Input policy can be "accept" (accept
silently), or "reject" (reject the request with an error).

-compat deprecated-output=<out-policy> configures what to do when
deprecated output is sent.  Output policy can be "accept" (pass on
unchanged), or "hide" (filter out the deprecated parts).

Default is "accept".  Policies other than "accept" are implemented
later in this series.

For now, -compat covers only syntactic aspects of QMP, i.e. stuff
tagged with feature 'deprecated'.  We may want to extend it to cover
semantic aspects, CLI, and experimental features.

Note that there is no good way for management application to detect
presence of -compat: it's not visible output of query-qmp-schema or
query-command-line-options.  Tolerable, because it's meant for
testing.  If running with -compat fails, skip the test.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210318155519.1224118-3-armbru@redhat.com>
2021-03-19 15:43:33 +01:00
Alexey Kirillov
a0724776c5 hmp: Use QAPI NetdevInfo in hmp_info_network
Replace usage of legacy field info_str of NetClientState for backend
network devices with QAPI NetdevInfo stored_config that already used
in QMP query-netdev.

This change increases the detail of the "info network" output and takes
a more general approach to composing the output.

NIC and hubports still use legacy info_str field.

Signed-off-by: Alexey Kirillov <lekiravi@yandex-team.ru>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-03-15 16:41:22 +08:00
Philippe Mathieu-Daudé
a0e61807a3 qapi: Remove QMP events and commands from user-mode builds
We removed the QMP loop in user-mode builds in commit 1935e0e4e0
("qapi/meson: Remove QMP from user-mode emulation"), now commands
and events code is unreachable.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210224171642.3242293-1-philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-03-05 15:40:49 +01:00
Philippe Mathieu-Daudé
c2651c0eaa qapi/meson: Restrict UI module to system emulation and tools
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210122204441.2145197-13-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-08 14:43:55 +01:00
Philippe Mathieu-Daudé
7fdb383d04 qapi/meson: Restrict system-mode specific modules
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210122204441.2145197-12-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-08 14:43:55 +01:00
Philippe Mathieu-Daudé
1935e0e4e0 qapi/meson: Remove QMP from user-mode emulation
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210122204441.2145197-11-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-08 14:43:55 +01:00
Philippe Mathieu-Daudé
9b45a025ed qapi/meson: Restrict qdev code to system-mode emulation
Beside a CPU device, user-mode emulation doesn't access
anything else from qdev subsystem.

Tools don't need anything from qdev.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210122204441.2145197-10-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-08 14:43:55 +01:00
Lukas Straub
50186051f4 Introduce yank feature
The yank feature allows to recover from hanging qemu by "yanking"
at various parts. Other qemu systems can register themselves and
multiple yank functions. Then all yank functions for selected
instances can be called by the 'yank' out-of-band qmp command.
Available instances can be queried by a 'query-yank' oob command.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <69934ceacfd33a7dfe53db145ecc630ad39ee47c.1609167865.git.lukasstraub2@web.de>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-01-13 10:21:17 +01:00
Pavel Dovgalyuk
43d7e1d782 qapi: introduce replay.json for record/replay-related stuff
This patch adds replay.json file. It will be
used for adding record/replay-related data structures and commands.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgalyuk@ispras.ru>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <160174519444.12451.3472949430004845434.stgit@pasha-ThinkPad-X280>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-06 08:34:49 +02:00
Kevin Wolf
5daa6bfd8e qapi: Create block-export module
Move all block export related types and commands from block-core to the
new QAPI module block-export.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200924152717.287415-3-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Peter Maydell
4ac2ee194b docs/interop: Convert qemu-qmp-ref to rST
Convert qemu-qmp-ref to rST format. This includes dropping
the plain-text, pdf and info format outputs for this document;
as with all our other Sphinx-based documentation, we provide
HTML and manpage only.

The qemu-qmp-ref.rst is somewhat more stripped down than
the .texi was, because we do not (currently) attempt to
generate indexes for the commands, events and data types
being documented.

Again, we drop the direct link from index.html.in now that
the QMP ref is part of the interop manual.

This commit removes the code from the root meson.build file that
handled the various Texinfo-based outputs, because we no longer
generate any documentation except for the Sphinx HTML manuals and the
manpages, and the code can't handle having an empty list of files
to process.. We'll do further cleanup of the remainders of
Texinfo support in subsequent commits.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200925162316.21205-10-peter.maydell@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Unicode legacy literal dumbed down to plain string literal, TODO
comment on displaying QEMU version added, "make html" fixed,
storage-daemon/qapi/meson.build updated]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-29 17:55:39 +02:00
Philippe Mathieu-Daudé
61c7f9876a qapi: Extract PCI commands to 'pci.json'
Only qemu-system-FOO and qemu-storage-daemon provide QMP
monitors, therefore such declarations and definitions are
irrelevant for user-mode emulation.

Extracting the PCI commands to their own schema reduces the size of
the qapi-misc* headers generated, and pulls less QAPI-generated code
into user-mode.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200913195348.1064154-9-philmd@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-29 15:41:36 +02:00
Philippe Mathieu-Daudé
27c9188fa0 qapi: Extract ACPI commands to 'acpi.json'
Only qemu-system-FOO and qemu-storage-daemon provide QMP
monitors, therefore such declarations and definitions are
irrelevant for user-mode emulation.

Extracting the ACPI commands to their own schema reduces the size of
the qapi-misc* headers generated, and pulls less QAPI-generated code
into user-mode.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200913195348.1064154-8-philmd@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-29 15:41:36 +02:00
Marc-André Lureau
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