[PATCH v7 00/11] Configurable policy for handling deprecated interfaces

[Markus Armbruster <armbru@redhat.com>]

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=<in-policy> configures what to do when
deprecated input is received.  Available policies:

* accept: Accept deprecated commands and arguments (default)
* reject: Reject them
* crash: Crash

-compat deprecated-output=<out-policy> configures what to do when
deprecated output is sent.  Available output policies:

* accept: Emit deprecated command results and events (default)
* hide: Suppress them

For now, -compat covers only deprecated syntactic aspects of QMP.  We
may want to extend it to cover semantic aspects, CLI, and experimental
features.

v7:
* Trivially rebased
* PATCH 01: New, bug fix from Paolo
* PATCH 02+11: Since: comments fixed, for real this time [Eric]
* PATCH 03+10: qobject_output_visitor_new_qmp() and
  qobject_input_visitor_new_qmp() moved to qmp-dispatch.c to not break
  --disable-system --disable-tools builds
* PATCH 05: Minor fallout from changed PATCH 03
* PATCH 06: Commit message typo fixed [Eric]

v6:
* Rebased, with straightforward conflicts
* PATCH 1: More verbose commit message, explaining intent, and the
  lack of introspection [Peter], comments updated for 6.0, Eric's R-by
  kept anyway
* PATCH 5+6: Split old PATCH 5 [Eric], Eric's R-by lept anyway
* PATCH 7: New, correcting a latent issue so it doesn't break PATCH 8
* PATCH 10: Doc fix [Eric]

v5:
* Old PATCH 01-26 merged in commit f57587c7d47.
* Rebased, non-trivial conflicts in PATCH 1 due to Meson, and in PATCH
  7 due to visitor changes
* PATCH 1: Comments updated for 5.2 [Eric]
* PATCH 2: Harmless missing initialization fixed [Eric]
* PATCH 3+4: Harmless missing has_FOO = true fixed [Eric]
* PATCH 6+7: Commit message tweaked

v4:
* PATCH 05+07: Temporary memory leak plugged [Marc-André]
* PATCH 23: Rewritten [Marc-André]
* PATCH 24: Comment typo [Marc-André]
* PATCH 30: Memory leaks plugged

v3:
* Rebased, non-trivial conflicts in PATCH 01+26+27+34 due to RST
  conversion and code motion
* PATCH 28-29: Old PATCH 28 split up to ease review
* PATCH 30-31: New
* PATCH 32-33: Old PATCH 29 split up to ease review

Comparison to RFC (24 Oct 2019):
* Cover arguments and results in addition to commands and events
* Half-baked "[RFC PATCH 18/19] qapi: Include a warning in the
  response to a deprecated command" dropped

See also last item of
    Subject: Minutes of KVM Forum BoF on deprecating stuff
    Date: Fri, 26 Oct 2018 16:03:51 +0200
    Message-ID: <87mur0ls8o.fsf@dusky.pond.sub.org>
    https://lists.nongnu.org/archive/html/qemu-devel/2018-10/msg05828.html

Cc: Lukáš Doktor <ldoktor@redhat.com>
Cc: libguestfs@redhat.com
Cc: libvir-list@redhat.com
Cc: Daniel P. Berrange <berrange@redhat.com>
Cc: Peter Krempa <pkrempa@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>

Markus Armbruster (10):
  qemu-options: New -compat to set policy for deprecated interfaces
  qapi: Implement deprecated-output=hide for QMP command results
  qapi: Implement deprecated-output=hide for QMP events
  qapi: Implement deprecated-output=hide for QMP event data
  monitor: Drop query-qmp-schema 'gen': false hack
  qapi: Implement deprecated-output=hide for QMP introspection
  test-util-sockets: Add stub for monitor_set_cur()
  qapi: Implement deprecated-input=reject for QMP commands
  qapi: Implement deprecated-input=reject for QMP command arguments
  qapi: New -compat deprecated-input=crash

Paolo Bonzini (1):
  qemuutil: remove qemu_set_fd_handler duplicate symbol

 qapi/compat.json                        |  52 ++++++++++++
 qapi/introspect.json                    |   2 +-
 qapi/qapi-schema.json                   |   1 +
 include/qapi/compat-policy.h            |  38 +++++++++
 include/qapi/qmp/dispatch.h             |   1 +
 include/qapi/qobject-input-visitor.h    |   4 +
 include/qapi/qobject-output-visitor.h   |   4 +
 include/qapi/visitor-impl.h             |   6 ++
 include/qapi/visitor.h                  |  18 +++++
 monitor/monitor-internal.h              |   3 -
 monitor/misc.c                          |   2 -
 monitor/qmp-cmds-control.c              | 100 +++++++++++++++++++++---
 qapi/qapi-visit-core.c                  |  18 +++++
 qapi/qmp-dispatch.c                     |  35 +++++++++
 qapi/qobject-input-visitor.c            |  29 +++++++
 qapi/qobject-output-visitor.c           |  19 +++++
 softmmu/vl.c                            |  17 ++++
 storage-daemon/qemu-storage-daemon.c    |   2 -
 stubs/set-fd-handler.c                  |  10 ---
 tests/unit/test-qmp-cmds.c              |  91 +++++++++++++++++++--
 tests/unit/test-qmp-event.c             |  41 ++++++++++
 tests/unit/test-util-sockets.c          |   1 +
 qapi/meson.build                        |   1 +
 qapi/trace-events                       |   2 +
 qemu-options.hx                         |  22 ++++++
 scripts/qapi/commands.py                |  17 ++--
 scripts/qapi/events.py                  |  21 ++++-
 scripts/qapi/visit.py                   |  15 ++++
 stubs/meson.build                       |   1 -
 tests/qapi-schema/qapi-schema-test.json |  20 +++--
 tests/qapi-schema/qapi-schema-test.out  |  20 ++---
 31 files changed, 549 insertions(+), 64 deletions(-)
 create mode 100644 qapi/compat.json
 create mode 100644 include/qapi/compat-policy.h
 delete mode 100644 stubs/set-fd-handler.c

-- 
2.26.3