Commit Graph

8 Commits

Author SHA1 Message Date
Eric Blake
15c2f669e3 qapi: Split visit_end_struct() into pieces
As mentioned in previous patches, we want to call visit_end_struct()
functions unconditionally, so that visitors can release resources
tied up since the matching visit_start_struct() without also having
to worry about error priority if more than one error occurs.

Even though error_propagate() can be safely used to ignore a second
error during cleanup caused by a first error, it is simpler if the
cleanup cannot set an error.  So, split out the error checking
portion (basically, input visitors checking for unvisited keys) into
a new function visit_check_struct(), which can be safely skipped if
any earlier errors are encountered, and leave the cleanup portion
(which never fails, but must be called unconditionally if
visit_start_struct() succeeded) in visit_end_struct().

Generated code in qapi-visit.c has diffs resembling:

|@@ -59,10 +59,12 @@ void visit_type_ACPIOSTInfo(Visitor *v,
|         goto out_obj;
|     }
|     visit_type_ACPIOSTInfo_members(v, obj, &err);
|-    error_propagate(errp, err);
|-    err = NULL;
|+    if (err) {
|+        goto out_obj;
|+    }
|+    visit_check_struct(v, &err);
| out_obj:
|-    visit_end_struct(v, &err);
|+    visit_end_struct(v);
| out:

and in qapi-event.c:

@@ -47,7 +47,10 @@ void qapi_event_send_acpi_device_ost(ACP
|         goto out;
|     }
|     visit_type_q_obj_ACPI_DEVICE_OST_arg_members(v, &param, &err);
|-    visit_end_struct(v, err ? NULL : &err);
|+    if (!err) {
|+        visit_check_struct(v, &err);
|+    }
|+    visit_end_struct(v);
|     if (err) {
|         goto out;

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-20-git-send-email-eblake@redhat.com>
[Conflict with a doc fixup resolved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:55 +02:00
Eric Blake
ad739706bb qom: Wrap prop visit in visit_start_struct
The qmp-input visitor was allowing callers to play rather fast
and loose: when visiting a QDict, you could grab members of the
root dictionary without first pushing into the dict; the final
such culprit was the QOM code for converting to and from object
properties.  But we are about to tighten the input visitor, at
which point user_creatable_add_type() as called with a QMP input
visitor via qmp_object_add() MUST follow the same paradigms as
everyone else, of pushing into the struct before grabbing its
keys.

The use of 'err ? NULL : &err' is temporary; a later patch will
clean that up when it splits visit_end_struct().

Furthermore, note that both callers always pass qdict, so we can
convert the conditional into an assert and reduce indentation.

The change has no impact to the testsuite now, but is required to
avoid a failure in tests/test-netfilter once qmp-input is made
stricter to detect inconsistent 'name' arguments on the root visit.

Since user_creatable_add_type() is also called with OptsVisitor
through user_creatable_add_opts(), we must also check that there
is no negative impact there; both pre- and post-patch, we see:

$ ./x86_64-softmmu/qemu-system-x86_64 -nographic -nodefaults -qmp stdio -object secret,id=sec0,data=letmein,format=raw,foo=bar
qemu-system-x86_64: -object secret,id=sec0,data=letmein,format=raw,foo=bar: Property '.foo' not found

That is, the only new checking that the new visit_end_struct() can
perform is for excess input, but we already catch excess input
earlier in object_property_set().

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-10-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Markus Armbruster
51b9b478cc qom: -object error messages lost location, restore it
qemu_opts_foreach() runs its callback with the error location set to
the option's location.  Any errors the callback reports use the
option's location automatically.

Commit 90998d5 moved the actual error reporting from "inside"
qemu_opts_foreach() to after it.  Here's a typical hunk:

	 if (qemu_opts_foreach(qemu_find_opts("object"),
    -                          object_create,
    -                          object_create_initial, NULL)) {
    +                          user_creatable_add_opts_foreach,
    +                          object_create_initial, &err)) {
    +        error_report_err(err);
	     exit(1);
	 }

Before, object_create() reports from within qemu_opts_foreach(), using
the option's location.  Afterwards, we do it after
qemu_opts_foreach(), using whatever location happens to be current
there.  Commonly a "none" location.

This is because Error objects don't have location information.
Problematic.

Reproducer:

    $ qemu-system-x86_64 -nodefaults -display none -object secret,id=foo,foo=bar
    qemu-system-x86_64: Property '.foo' not found

Note no location.  This commit restores it:

    qemu-system-x86_64: -object secret,id=foo,foo=bar: Property '.foo' not found

Note that the qemu_opts_foreach() bug just fixed could mask the bug
here: if the location it leaves dangling hasn't been clobbered, yet,
it's the correct one.

Reported-by: Eric Blake <eblake@redhat.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1461767349-15329-4-git-send-email-armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Paragraph on Error added to commit message]
2016-04-28 08:19:36 +02:00
Markus Armbruster
da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00
Daniel P. Berrange
90998d5896 qom: add helpers for UserCreatable object types
The QMP monitor code has two helper methods object_add
and qmp_object_del that are called from several places
in the code (QMP, HMP and main emulator startup).

The HMP and main emulator startup code also share
further logic that extracts the qom-type & id
values from a qdict.

We soon need to use this logic from qemu-img, qemu-io
and qemu-nbd too, but don't want those to depend on
the monitor, nor do we want to duplicate the code.

To avoid this, move some code out of qmp.c and hmp.c
adding new methods to qom/object_interfaces.c

 - user_creatable_add - takes a QDict holding a full
   object definition & instantiates it
 - user_creatable_add_type - takes an ID, type name,
   and QDict holding object properties & instantiates
   it
 - user_creatable_add_opts - takes a QemuOpts holding
   a full object definition & instantiates it
 - user_creatable_add_opts_foreach - variant on
   user_creatable_add_opts which can be directly used
   in conjunction with qemu_opts_foreach.
 - user_creatable_del - takes an ID and deletes the
   corresponding object

The existing code is updated to use these new methods.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1455129674-17255-2-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 17:12:57 +01:00
Peter Maydell
9bbc853bd4 qom: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1454089805-5470-13-git-send-email-peter.maydell@linaro.org
2016-02-04 17:41:30 +00:00
Lin Ma
d6edb15576 qom: Add can_be_deleted callback to UserCreatableClass
If backends implement the can_be_deleted and it returns false,
Then the qmp_object_del won't delete the given backends.

Signed-off-by: Lin Ma <lma@suse.com>
Message-Id: <1427704589-7688-2-git-send-email-lma@suse.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-04-01 10:06:38 +02:00
Igor Mammedov
269e09f3fc add optional 2nd stage initialization to -object/object-add commands
Introduces USER_CREATABLE interface that must be implemented by
objects which are designed to created with -object CLI option or
object-add QMP command.

Interface provides an ability to do an optional second stage
initialization of the object created with -object/object-add
commands. By providing complete() callback, which is called
after the object properties were set.

It allows to:
 * prevents misusing of -object/object-add by filtering out
   objects that are not designed for it.
 * generalize second stage backend initialization instead of
   adding custom APIs to perform it
 * early error detection of backend initialization at -object/
   object-add time rather than through a proxy DEVICE object
   that tries to use backend.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-01-28 12:47:02 -05:00