Re: [Qemu-devel] [PATCH] fix assertion in "info memory-devices" if memdev isn't accessible

[Luiz Capitulino <lcapitulino@redhat.com>]

On Thu, 26 Mar 2015 15:59:25 -0400
Luiz Capitulino <lcapitulino@redhat.com> wrote:

> On Thu, 26 Mar 2015 16:42:54 +0000
> Igor Mammedov <imammedo@redhat.com> wrote:
> 
> > showing a memory device whose memdev is removed leads to an assert:
> > 
> > (qemu) object_add memory-backend-ram,id=ram0,size=128M
> > (qemu) device_add pc-dimm,id=d0,memdev=ram0
> > (qemu) object_del ram0
> > (qemu) info memory-devices
> > **
> > ERROR:qom/object.c:1274:object_get_canonical_path_component:\
> >                             assertion failed: (obj->parent != NULL)
> > Aborted
> > 
> > so check if memdev is present before calling
> > object_get_canonical_path() and in case it's not assign to
> > "memdev:" field "removed" value.
> > 
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> 
> Igor, do you want to go in through my tree?

What about the patch, btw? :)

> 
> > ---
> > alternative more generic solution:
> >    http://patchwork.ozlabs.org/patch/453343/
> > ---
> >  backends/hostmem.c       | 23 +++++++++++++++++++++++
> >  hw/mem/pc-dimm.c         | 15 ++++++++++++++-
> >  include/sysemu/hostmem.h |  1 +
> >  qmp.c                    |  1 +
> >  4 files changed, 39 insertions(+), 1 deletion(-)
> > 
> > diff --git a/backends/hostmem.c b/backends/hostmem.c
> > index 99e8f99..aa88691 100644
> > --- a/backends/hostmem.c
> > +++ b/backends/hostmem.c
> > @@ -227,6 +227,26 @@ static void host_memory_backend_set_prealloc(Object *obj, bool value,
> >      }
> >  }
> >  
> > +static void host_memory_backend_set_id(Object *obj, const char *id,
> > +                                       Error **errp)
> > +{
> > +    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
> > +
> > +    if (backend->id) {
> > +        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "id",
> > +                  "can't change already set value");
> > +        return;
> > +    }
> > +    backend->id = g_strdup(id);
> > +}
> > +
> > +static char *host_memory_backend_get_id(Object *obj, Error **errp)
> > +{
> > +    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
> > +
> > +    return g_strdup(backend->id);
> > +}
> > +
> >  static void host_memory_backend_init(Object *obj)
> >  {
> >      HostMemoryBackend *backend = MEMORY_BACKEND(obj);
> > @@ -237,6 +257,9 @@ static void host_memory_backend_init(Object *obj)
> >                                        "dump-guest-core", true);
> >      backend->prealloc = mem_prealloc;
> >  
> > +    object_property_add_str(obj, "id",
> > +                            host_memory_backend_get_id,
> > +                            host_memory_backend_set_id, NULL);
> >      object_property_add_bool(obj, "merge",
> >                          host_memory_backend_get_merge,
> >                          host_memory_backend_set_merge, NULL);
> > diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> > index 39f0c97..482a7a0 100644
> > --- a/hw/mem/pc-dimm.c
> > +++ b/hw/mem/pc-dimm.c
> > @@ -69,6 +69,8 @@ int qmp_pc_dimm_device_list(Object *obj, void *opaque)
> >          DeviceState *dev = DEVICE(obj);
> >  
> >          if (dev->realized) {
> > +            char *mdevid, *mdevpath;
> > +            Object *mdev;
> >              MemoryDeviceInfoList *elem = g_new0(MemoryDeviceInfoList, 1);
> >              MemoryDeviceInfo *info = g_new0(MemoryDeviceInfo, 1);
> >              PCDIMMDeviceInfo *di = g_new0(PCDIMMDeviceInfo, 1);
> > @@ -86,7 +88,18 @@ int qmp_pc_dimm_device_list(Object *obj, void *opaque)
> >              di->node = dimm->node;
> >              di->size = object_property_get_int(OBJECT(dimm), PC_DIMM_SIZE_PROP,
> >                                                 NULL);
> > -            di->memdev = object_get_canonical_path(OBJECT(dimm->hostmem));
> > +            mdevid = object_property_get_str(OBJECT(dimm->hostmem), "id",
> > +                                             &error_abort);
> > +            mdevpath = g_strdup_printf("/objects/%s", mdevid);
> > +            g_free(mdevid);
> > +            mdev = object_resolve_path_type(mdevpath, TYPE_MEMORY_BACKEND,
> > +                                            NULL);
> > +            if (mdev == OBJECT(dimm->hostmem)) {
> > +                di->memdev = object_get_canonical_path(OBJECT(dimm->hostmem));
> > +            } else {
> > +                di->memdev = g_strdup("removed");
> > +            }
> > +            g_free(mdevpath);
> >  
> >              info->dimm = di;
> >              elem->value = info;
> > diff --git a/include/sysemu/hostmem.h b/include/sysemu/hostmem.h
> > index 1ce4394..63918aa 100644
> > --- a/include/sysemu/hostmem.h
> > +++ b/include/sysemu/hostmem.h
> > @@ -53,6 +53,7 @@ struct HostMemoryBackend {
> >      Object parent;
> >  
> >      /* protected */
> > +    char *id;
> >      uint64_t size;
> >      bool merge, dump;
> >      bool prealloc, force_prealloc;
> > diff --git a/qmp.c b/qmp.c
> > index c479e77..6f1cca7 100644
> > --- a/qmp.c
> > +++ b/qmp.c
> > @@ -649,6 +649,7 @@ void object_add(const char *type, const char *id, const QDict *qdict,
> >              }
> >          }
> >      }
> > +    object_property_set_str(obj, id, "id", NULL);
> >  
> >      object_property_add_child(container_get(object_get_root(), "/objects"),
> >                                id, obj, &local_err);
>