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 checks in {qmp,hmp}_object_del 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" <dgilb...@redhat.com> Cc: Markus Armbruster <arm...@redhat.com> Cc: Eric Blake <ebl...@redhat.com> Cc: Daniel Berrange <berra...@redhat.com> Signed-off-by: Michael Roth <mdr...@linux.vnet.ibm.com> --- hmp.c | 10 ++++++++++ qmp.c | 10 ++++++++++ 2 files changed, 20 insertions(+) diff --git a/hmp.c b/hmp.c index b869617..99b8bf3 100644 --- a/hmp.c +++ b/hmp.c @@ -2072,6 +2072,16 @@ void hmp_object_del(Monitor *mon, const QDict *qdict) user_creatable_del(id, &err); hmp_handle_error(mon, &err); + + /* if object was defined on the command-line, remove its corresponding + * option group entry + */ + if (err == NULL) { + QemuOptsList *opt_group = qemu_find_opts_err("object", &err); + if (opt_group) { + qemu_opts_del(qemu_opts_find(opt_group, id)); + } + } } void hmp_info_memdev(Monitor *mon, const QDict *qdict) diff --git a/qmp.c b/qmp.c index 0028f0b..87c545d 100644 --- a/qmp.c +++ b/qmp.c @@ -686,6 +686,16 @@ void qmp_object_add(const char *type, const char *id, void qmp_object_del(const char *id, Error **errp) { user_creatable_del(id, errp); + + /* if object was defined on the command-line, remove its corresponding + * option group entry + */ + if (!(errp && *errp)) { + QemuOptsList *opt_group = qemu_find_opts_err("object", errp); + if (opt_group) { + qemu_opts_del(qemu_opts_find(opt_group, id)); + } + } } MemoryDeviceInfoList *qmp_query_memory_devices(Error **errp) -- 1.9.1