OpenE2K/qemu-e2k
13
4
Fork 0
Code Issues 4 Pull Requests Projects 2 Releases Activity

monitor: fix object_del for command-line-created objects

Browse Source 
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>
This commit is contained in:
Michael Roth 2017-06-03 18:13:32 -05:00 committed by Markus Armbruster
parent a1af255f06
commit c645d5acee
2 changed files with 11 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
qom/object_interfaces.c
View File

@ -4,6 +4,7 @@
#include "qemu/module.h"
#include "qapi-visit.h"
#include "qapi/opts-visitor.h"
#include "qemu/config-file.h"
void user_creatable_complete(Object *obj, Error **errp)
{
@ -181,6 +182,14 @@ void user_creatable_del(const char *id, Error **errp)
error_setg(errp, "object '%s' is in use, can not be deleted", id);
return;
}
/*
* if object was defined on the command-line, remove its corresponding
* option group entry
*/
qemu_opts_del(qemu_opts_find(qemu_find_opts_err("object", &error_abort),
id));
object_unparent(obj);
}

4
tests/check-qom-proplist.c
View File

@ -438,9 +438,9 @@ static void test_dummy_createcmdl(void)
* check for this in user_creatable_del() and remove the QemuOpts if
* it is present.
*
* FIXME: add an assert to verify that the QemuOpts is cleaned up
* once the corresponding cleanup code is added.
* The below check ensures this works as expected.
*/
g_assert_null(qemu_opts_find(&qemu_object_opts, "dev0"));
}
static void test_dummy_badenum(void)