The code to check policy for handling deprecated input is triplicated.
Factor it out into compat_policy_input_ok() before I mess with it in
the next commit.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20211028102520.747396-9-armbru@redhat.com>
[Policy code moved from qmp-dispatch.c to qapi-util.c to make visitors
link without qmp-dispatch.o]
This policy rejects deprecated input, and thus permits "testing the
future". Implement it for QMP command arguments: reject commands with
deprecated ones. Example: when QEMU is run with -compat
deprecated-input=reject, then
{"execute": "eject", "arguments": {"device": "cd"}}
fails like this
{"error": {"class": "GenericError", "desc": "Deprecated parameter 'device' disabled by policy"}}
When the deprecated parameter is removed, the error will change to
{"error": {"class": "GenericError", "desc": "Parameter 'device' is unexpected"}}
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210318155519.1224118-11-armbru@redhat.com>
This policy suppresses deprecated bits in output, and thus permits
"testing the future". Implement it for QMP command results. Example:
when QEMU is run with -compat deprecated-output=hide, then
{"execute": "query-cpus-fast"}
yields
{"return": [{"thread-id": 9805, "props": {"core-id": 0, "thread-id": 0, "socket-id": 0}, "qom-path": "/machine/unattached/device[0]", "cpu-index": 0, "target": "x86_64"}]}
instead of
{"return": [{"arch": "x86", "thread-id": 22436, "props": {"core-id": 0, "thread-id": 0, "socket-id": 0}, "qom-path": "/machine/unattached/device[0]", "cpu-index": 0, "target": "x86_64"}]}
Note the suppression of deprecated member "arch".
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210318155519.1224118-4-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=<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>
