Commit Graph

17 Commits

Author SHA1 Message Date
Michael Roth
c645d5acee monitor: fix object_del for command-line-created objects
Currently objects specified on the command-line are only partially
cleaned up when 'object_del' is issued in either HMP or QMP: the
object itself is fully finalized, but the QemuOpts are not removed.
This results in the following behavior:

  x86_64-softmmu/qemu-system-x86_64 -monitor stdio \
    -object memory-backend-ram,id=ram1,size=256M

  QEMU 2.7.91 monitor - type 'help' for more information
  (qemu) object_del ram1
  (qemu) object_del ram1
  object 'ram1' not found
  (qemu) object_add memory-backend-ram,id=ram1,size=256M
  Duplicate ID 'ram1' for object
  Try "help object_add" for more information

which can be an issue for use-cases like memory hotplug.

This happens on the HMP side because hmp_object_add() attempts to
create a temporary QemuOpts entry with ID 'ram1', which ends up
conflicting with the command-line-created entry, since it was never
cleaned up during the previous hmp_object_del() call.

We address this by adding a check in user_creatable_del(), which
is called by both qmp_object_del() and hmp_object_del() to handle
the actual object cleanup, to determine whether an option group entry
matching the object's ID is present and removing it if it is.

Note that qmp_object_add() never attempts to create a temporary
QemuOpts entry, so it does not encounter the duplicate ID error,
which is why this isn't generally visible in libvirt.

Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Daniel Berrange <berrange@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1496531612-22166-3-git-send-email-mdroth@linux.vnet.ibm.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-06-06 09:29:46 +02:00
Eric Blake
0832970119 qom: Fix regression with 'qom-type'
Commit 9a6d1ac assumed that 'qom-type' could be removed from QemuOpts
with no ill effects.  However, this command line proves otherwise:

$ ./x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic -qmp stdio \
  -object rng-random,filename=/dev/urandom,id=rng0 \
  -device virtio-rng-pci,rng=rng0
qemu-system-x86_64: -object rng-random,filename=/dev/urandom,id=rng0: Parameter 'qom-type' is missing

Fix the regression by restoring qom-type in opts after its temporary
removal that was needed for the duration of user_creatable_add_opts().

Reported-by: Richard W. M. Jones <rjones@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Message-id: 20170323160315.19696-1-eblake@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-03-23 17:59:40 +00:00
Eric Blake
9a6d1acb3e qom: Avoid unvisited 'id'/'qom-type' in user_creatable_add_opts
A regression in commit 15c2f669e caused us to silently ignore
excess input to the QemuOpts visitor.  Later, commit ea4641
accidentally abused that situation, by removing "qom-type" and
"id" from the corresponding QDict but leaving them defined in
the QemuOpts, when using the pair of containers to create a
user-defined object. Note that since we are already traversing
two separate items (a QDict and a QemuOpts), we are already
able to flag bogus arguments, as in:

$ ./x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic -qmp stdio -object memory-backend-ram,id=mem1,size=4k,bogus=huh
qemu-system-x86_64: -object memory-backend-ram,id=mem1,size=4k,bogus=huh: Property '.bogus' not found

So the only real concern is that when we re-enable strict checking
in the QemuOpts visitor, we do not want to start flagging the two
leftover keys as unvisited.  Rearrange the code to clean out the
QemuOpts listing in advance, rather than removing items from the
QDict.  Since "qom-type" is usually an automatic implicit default,
we don't have to restore it (this does mean that once instantiated,
QemuOpts is not necessarily an accurate representation of the
original command line - but this is not the first place to do that);
however "id" has to be put back (requiring us to cast away a const).

[As a side note, hmp_object_add() turns a QDict into a QemuOpts,
then calls user_creatable_add_opts() which converts QemuOpts into
a new QDict. There are probably a lot of wasteful conversions like
this, but cleaning them up is a much bigger task than the immediate
regression fix.]

CC: qemu-stable@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170322144525.18964-3-eblake@redhat.com>
Tested-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-03-22 19:24:34 +01:00
Igor Mammedov
e1ff3c67e8 monitor: fix qmp/hmp query-memdev not reporting IDs of memory backends
Considering 'id' is mandatory for user_creatable objects/backends
and user_creatable_add_type() always has it as an argument
regardless of where from it is called CLI/monitor or QMP,
Fix issue by adding 'id' property to hostmem backends and
set it in user_creatable_add_type() for every object that
implements 'id' property. Then later at query-memdev time
get 'id' from object directly.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <1484052795-158195-4-git-send-email-imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2017-01-12 15:35:06 -02:00
Igor Mammedov
3a4641054e monitor: reuse user_creatable_add_opts() instead of user_creatable_add()
Simplify code by dropping ~57LOC by merging user_creatable_add()
into user_creatable_add_opts() and using the later from monitor.
Along with it allocate opts_visitor_new() once in user_creatable_add_opts().

As result we have one less API func and a more readable/simple
user_creatable_add_opts() vs user_creatable_add().

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1484052795-158195-3-git-send-email-imammedo@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2017-01-12 15:34:47 -02:00
Igor Mammedov
8a000250f1 qom: remove unused header
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1484052795-158195-2-git-send-email-imammedo@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2017-01-12 11:32:58 -02:00
Daniel P. Berrange
b3db211f3c qapi: rename *qmp-*-visitor* to *qobject-*-visitor*
The QMP visitors have no direct dependency on QMP. It is
valid to use them anywhere that one has a QObject. Rename them
to better reflect their functionality as a generic QObject
to QAPI converter.

This is the first of three parts: rename the files.  The next two
parts will rename C identifiers.  The split is necessary to make git
rename detection work.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Split into file and identifier rename, two comments touched up]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-10-25 16:25:48 +02:00
Eric Blake
09204eac9b opts-visitor: Favor new visit_free() function
Now that we have a polymorphic visit_free(), we no longer need
opts_visitor_cleanup(); which in turn means we no longer need
to return a subtype from opts_visitor_new() nor a public upcast
function.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-6-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06 10:52:04 +02:00
Eric Blake
1158bb2a05 qapi: Add parameter to visit_end_*
Rather than making the dealloc visitor track of stack of pointers
remembered during visit_start_* in order to free them during
visit_end_*, it's a lot easier to just make all callers pass the
same pointer to visit_end_*.  The generated code has access to the
same pointer, while all other users are doing virtual walks and
can pass NULL.  The dealloc visitor is then greatly simplified.

All three visit_end_*() functions intentionally take a void**,
even though the visit_start_*() functions differ between void**,
GenericList**, and GenericAlternate**.  This is done for several
reasons: when doing a virtual walk, passing NULL doesn't care
what the type is, but when doing a generated walk, we already
have to cast the caller's specific FOO* to call visit_start,
while using void** lets us use visit_end without a cast. Also,
an upcoming patch will add a clone visitor that wants to use
the same implementation for all three visit_end callbacks,
which is made easier if all three share the same signature.

For visitors with already track per-object state (the QMP visitors
via a stack, and the string visitors which do not allow nesting),
add an assertion that the caller is indeed passing the same
pointer to paired calls.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-4-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06 10:52:04 +02:00
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