qapi: Factor out compat_policy_input_ok()

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.

qapi: Factor out compat_policy_input_ok()

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]

show more ...

qapi: Generalize enum member policy checking

The code to check enumeration value policy can see special feature
flag 'deprecated' in QEnumLookup member flags[value]. I want to make
feature flag 'un

qapi: Generalize enum member policy checking

The code to check enumeration value policy can see special feature
flag 'deprecated' in QEnumLookup member flags[value]. I want to make
feature flag 'unstable' visible there as well, so I can add policy for
it.

Instead of extending flags[], replace it by @special_features (a
bitset of QapiSpecialFeature), because that's how special features get
passed around elsewhere.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: John Snow <jsnow@redhat.com>
Message-Id: <20211028102520.747396-8-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

show more ...

qapi: Generalize struct member policy checking

The generated visitor functions call visit_deprecated_accept() and
visit_deprecated() when visiting a struct member with special feature
flag 'deprecat

qapi: Generalize struct member policy checking

The generated visitor functions call visit_deprecated_accept() and
visit_deprecated() when visiting a struct member with special feature
flag 'deprecated'. This makes the feature flag visible to the actual
visitors. I want to make feature flag 'unstable' visible there as
well, so I can add policy for it.

To let me make it visible, replace these functions by
visit_policy_reject() and visit_policy_skip(), which take the member's
special features as an argument. Note that the new functions have the
opposite sense, i.e. the return value flips.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20211028102520.747396-6-armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Unbreak forward visitor]

show more ...

qapi: Implement deprecated-input={reject,crash} for enum values

This copies the code implementing the policy from qapi/qmp-dispatch.c
to qapi/qobject-input-visitor.c. Tolerable, but if we acquire m

qapi: Implement deprecated-input={reject,crash} for enum values

This copies the code implementing the policy from qapi/qmp-dispatch.c
to qapi/qobject-input-visitor.c. Tolerable, but if we acquire more
copies, we should look into factoring them out.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Message-Id: <20211025042405.3762351-5-armbru@redhat.com>

show more ...

qapi: Move compat policy from QObject to generic visitor

The next commit needs to access compat policy from the generic visitor
core. Move it there from qobject input and output visitor.

Signed-of

qapi: Move compat policy from QObject to generic visitor

The next commit needs to access compat policy from the generic visitor
core. Move it there from qobject input and output visitor.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20211025042405.3762351-4-armbru@redhat.com>

show more ...

qapi: Improve input_type_enum()'s error message

The error message claims the parameter is invalid:

$ qemu-system-x86_64 -object qom-type=nonexistent
qemu-system-x86_64: -object qom-type=non

qapi: Improve input_type_enum()'s error message

The error message claims the parameter is invalid:

$ qemu-system-x86_64 -object qom-type=nonexistent
qemu-system-x86_64: -object qom-type=nonexistent: Invalid parameter 'nonexistent'

What's wrong is actually the *value* 'nonexistent'. Improve the
message to

qemu-system-x86_64: -object qom-type=nonexistent: Parameter 'qom-type' does not accept value 'nonexistent'

Fixes: https://gitlab.com/qemu-project/qemu/-/issues/608
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20211020180231.434071-1-armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qapi: Implement deprecated-input=reject for QMP command arguments

This policy rejects deprecated input, and thus permits "testing the
future". Implement it for QMP command arguments: reject command

qapi: Implement deprecated-input=reject for QMP command arguments

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>

show more ...

qapi: Implement deprecated-output=hide for QMP command results

This policy suppresses deprecated bits in output, and thus permits
"testing the future". Implement it for QMP command results. Exampl

qapi: Implement deprecated-output=hide for QMP command results

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>

show more ...

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>

qapi: Make visitor functions taking Error ** return bool, not void

See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Revi

qapi: Make visitor functions taking Error ** return bool, not void

See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-18-armbru@redhat.com>

show more ...

qapi: Assert non-input visitors see only valid narrow integers

visit_type_intN() and visit_type_uintN() fail when the value is out of
bounds.

This is appropriate with an input visitor: the value co

qapi: Assert non-input visitors see only valid narrow integers

visit_type_intN() and visit_type_uintN() fail when the value is out of
bounds.

This is appropriate with an input visitor: the value comes from input,
and input may be bad.

It should never happen with the other visitors: the value comes from
the caller, and callers must keep it within bounds. Assert that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-10-armbru@redhat.com>

show more ...

qapi: Assert output visitors see only valid enum values

output_type_enum() fails when *obj is not a valid value of the enum
type. Should not happen. Drop the check, along with its unit tests.
This

qapi: Assert output visitors see only valid enum values

output_type_enum() fails when *obj is not a valid value of the enum
type. Should not happen. Drop the check, along with its unit tests.
This unmasks qapi_enum_lookup()'s assertion.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-9-armbru@redhat.com>
[Commit message tweaked]

show more ...

qapi: Assert incomplete object occurs only in dealloc visitor

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-7-arm

qapi: Assert incomplete object occurs only in dealloc visitor

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-7-armbru@redhat.com>

show more ...

Include qemu-common.h exactly where needed

No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Me

Include qemu-common.h exactly where needed

No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]

show more ...

Include qapi/qmp/qobject.h exactly where needed

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

Include qapi/qmp/qobject.h exactly where needed

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-11-armbru@redhat.com>

show more ...

qapi: Change data type of the FOO_lookup generated for enum FOO

Currently, a FOO_lookup is an array of strings terminated by a NULL
sentinel.

A future patch will generate enums with "holes". NULL-

qapi: Change data type of the FOO_lookup generated for enum FOO

Currently, a FOO_lookup is an array of strings terminated by a NULL
sentinel.

A future patch will generate enums with "holes". NULL-termination
will cease to work then.

To prepare for that, store the length in the FOO_lookup by wrapping it
in a struct and adding a member for the length.

The sentinel will be dropped next.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170822132255.23945-13-marcandre.lureau@redhat.com>
[Basically redone]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-16-git-send-email-armbru@redhat.com>
[Rebased]

show more ...

qapi: Convert indirect uses of FOO_lookup[...] to qapi_enum_lookup()

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-15-git-send-email-armbru@redhat.com>
Reviewed-

qapi: Convert indirect uses of FOO_lookup[...] to qapi_enum_lookup()

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-15-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

show more ...

qapi: Generate FOO_str() macro for QAPI enum FOO

The next commit will put it to use. May look pointless now, but we're
going to change the FOO_lookup's type, and then it'll help.

Signed-off-by: Ma

qapi: Generate FOO_str() macro for QAPI enum FOO

The next commit will put it to use. May look pointless now, but we're
going to change the FOO_lookup's type, and then it'll help.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-13-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

show more ...

qapi: Use qapi_enum_parse() in input_type_enum()

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-11-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lurea

qapi: Use qapi_enum_parse() in input_type_enum()

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-11-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

show more ...

qapi: Use QNull for a more regular visit_type_null()

Make visit_type_null() take an @obj argument like its buddies. This
helps keep the next commit simple.

Signed-off-by: Markus Armbruster <armbru

qapi: Use QNull for a more regular visit_type_null()

Make visit_type_null() take an @obj argument like its buddies. This
helps keep the next commit simple.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>

show more ...

qapi: Remove visit_start_alternate() parameter promote_int

Before the previous commit, parameter promote_int = true made
visit_start_alternate() with an input visitor avoid QTYPE_QINT
variants and c

qapi: Remove visit_start_alternate() parameter promote_int

Before the previous commit, parameter promote_int = true made
visit_start_alternate() with an input visitor avoid QTYPE_QINT
variants and create QTYPE_QFLOAT variants instead. This was used
where QTYPE_QINT variants were invalid.

The previous commit fused QTYPE_QINT with QTYPE_QFLOAT, rendering
promote_int useless and unused.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170607163635.17635-8-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Make input visitors detect unvisited list tails

Fix the design flaw demonstrated in the previous commit: new method
check_list() lets input visitors report that unvisited input remains
for a l

qapi: Make input visitors detect unvisited list tails

Fix the design flaw demonstrated in the previous commit: new method
check_list() lets input visitors report that unvisited input remains
for a list, exactly like check_struct() lets them report that
unvisited input remains for a struct or union.

Implement the method for the qobject input visitor (straightforward),
and the string input visitor (less so, due to the magic list syntax
there). The opts visitor's list magic is even more impenetrable, and
all I can do there today is a stub with a FIXME comment. No worse
than before.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1488544368-30622-26-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

show more ...

qapi: add missing trace_visit_type_enum() call

A trace event exists for enums but it's never called. This patch fixes
this oversight so that enums are traced just like the other QAPI types.

Sugges

qapi: add missing trace_visit_type_enum() call

A trace event exists for enums but it's never called. This patch fixes
this oversight so that enums are traced just like the other QAPI types.

Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20170126171613.1399-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

show more ...

qapi: add trace events for visitor

Allow tracing of the operation of visitors

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1475246744-29302-4-git-send-email-berrange@redhat.

qapi: add trace events for visitor

Allow tracing of the operation of visitors

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1475246744-29302-4-git-send-email-berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[visit_type_uint8() & friends rearranged slightly for clarity]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Add new clone visitor

We have a couple places in the code base that want to deep-clone
one QAPI object into another, and they were resorting to serializing
the struct out to QObject then repar

qapi: Add new clone visitor

We have a couple places in the code base that want to deep-clone
one QAPI object into another, and they were resorting to serializing
the struct out to QObject then reparsing it. A much more efficient
version can be done by adding a new clone visitor.

Since cloning is still relatively uncommon, expose the use of the
new visitor via a QAPI_CLONE() macro that takes care of type-punning
the underlying function pointer, rather than generating lots of
unused functions for types that won't be cloned. And yes, we're
relying on the compiler treating all pointers equally, even though
a strict C program cannot portably do so - but we're not the first
one in the qemu code base to expect it to work (hello, glib!).

The choice of adding a fourth visitor type deserves some explanation.
On the surface, the clone visitor is mostly an input visitor (it
takes arbitrary input - in this case, another QAPI object - and
creates a new QAPI object during the course of the visit). But
ever since commit da72ab0 consolidated enum visits based on the
visitor type, using VISITOR_INPUT would cause us to run
visit_type_str(), even though for cloning there is nothing to do
(we just copy the enum value across, without regards to its mapping
to strings). Also, since our input happens to be a QAPI object,
we can also satisfy the internal checks for VISITOR_OUTPUT. So in
the end, I settled with a new VISITOR_CLONE, and chose its value
such that many internal checks can use 'v->type & mask', sticking
to 'v->type == value' where the difference matters.

Note that we can only clone objects (including alternates) and lists,
not built-ins or enums. The visitor core hides integer width from
the actual visitor (since commit 04e070d), and as long as that's the
case, we can't clone top-level integers. Then again, those can
always be cloned by direct copy, since they are not objects with
deep pointers, so it's no real loss. And restricting cloning to
just objects and lists is cleaner than restricting it to non-integers.
As such, I documented that the clone visitor is for direct use only
by code internal to QAPI, and should not be used on incomplete objects
(other than a hack to work around the fact that we allow NULL in place
of "" in visit_type_str() in other output visitors). Note that as
written, the clone visitor will never fail on a complete object.

Scalars (including enums) not at the root of the clone copy just fine
with no additional effort while visiting the scalar, by virtue of a
g_memdup() each time we push another struct onto the stack. Cloning
a string requires deduplication of a pointer, which means it can also
provide the guarantee of an input visitor of never producing NULL
even when still accepting NULL in place of "" the way the QMP output
visitor does.

Cloning an 'any' type could be possible by incrementing the QObject
refcnt, but it's not obvious whether that is better than implementing
a QObject deep clone. So for now, we document it as unsupported,
and intentionally omit the .type_any() callback to let a developer
know their usage needs implementation.

Add testsuite coverage for several different clone situations, to
ensure that the code is working. I also tested that valgrind was
happy with the test.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-14-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...