[Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Marcel Apfelbaum]

The commits:
 - 6a1fa9f5 (monitor: add del completion for peripheral device)
 - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)

cause a QEMU crash when trying to use HMP device_del auto-completion.
It can be easily reproduced by:
    <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet

    (qemu) device_del
    /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
    Aborted (core dumped)

The root cause is qdev_build_hotpluggable_device_list going recursively over
all peripherals and their children assuming all are devices. It doesn't work
since PCI devices have at least on child which is a memory region (bus master).

Solved by observing that all devices appear as direct children of
/machine/peripheral container. No need of going recursively
over all the children.

Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
---
 hw/core/qdev.c         | 12 ++++++++++--
 include/hw/qdev-core.h |  2 +-
 monitor.c              | 11 ++++-------
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 413b413..35fd00d 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
     } while (class != object_class_by_name(TYPE_DEVICE));
 }
 
-int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
+static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
 {
     GSList **list = opaque;
     DeviceState *dev = DEVICE(obj);
@@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
         *list = g_slist_append(*list, dev);
     }
 
-    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
     return 0;
 }
 
+GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
+{
+    GSList *list = NULL;
+
+    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
+
+    return list;
+}
+
 static bool device_get_realized(Object *obj, Error **errp)
 {
     DeviceState *dev = DEVICE(obj);
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index d3a2940..589bbe7 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -365,7 +365,7 @@ extern int qdev_hotplug;
 
 char *qdev_get_dev_path(DeviceState *dev);
 
-int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
+GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
 
 void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
                               Error **errp);
diff --git a/monitor.c b/monitor.c
index fa00594..f1031a1 100644
--- a/monitor.c
+++ b/monitor.c
@@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
 static void peripheral_device_del_completion(ReadLineState *rs,
                                              const char *str, size_t len)
 {
-    Object *peripheral;
-    GSList *list = NULL, *item;
+    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
+    GSList *list, *item;
 
-    peripheral = object_resolve_path("/machine/peripheral/", NULL);
-    if (peripheral == NULL) {
+    list = qdev_build_hotpluggable_device_list(peripheral);
+    if (!list) {
         return;
     }
 
-    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
-                         &list);
-
     for (item = list; item; item = g_slist_next(item)) {
         DeviceState *dev = item->data;
 
-- 
1.9.3

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Igor Mammedov]

On Wed, 26 Nov 2014 13:50:01 +0200
Marcel Apfelbaum <marcel.a@redhat.com> wrote:

> The commits:
>  - 6a1fa9f5 (monitor: add del completion for peripheral device)
>  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> 
> cause a QEMU crash when trying to use HMP device_del auto-completion.
> It can be easily reproduced by:
>     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> 
>     (qemu) device_del
>     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
>     Aborted (core dumped)
> 
> The root cause is qdev_build_hotpluggable_device_list going recursively over
> all peripherals and their children assuming all are devices. It doesn't work
> since PCI devices have at least on child which is a memory region (bus master).
> 
> Solved by observing that all devices appear as direct children of
> /machine/peripheral container. No need of going recursively
> over all the children.
> 
> Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  hw/core/qdev.c         | 12 ++++++++++--
>  include/hw/qdev-core.h |  2 +-
>  monitor.c              | 11 ++++-------
>  3 files changed, 15 insertions(+), 10 deletions(-)
> 
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index 413b413..35fd00d 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
>      } while (class != object_class_by_name(TYPE_DEVICE));
>  }
>  
> -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
>  {
>      GSList **list = opaque;
>      DeviceState *dev = DEVICE(obj);
> @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
>          *list = g_slist_append(*list, dev);
>      }
>  
> -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
>      return 0;
>  }
>  
> +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> +{
> +    GSList *list = NULL;
> +
> +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> +
> +    return list;
> +}
> +
>  static bool device_get_realized(Object *obj, Error **errp)
>  {
>      DeviceState *dev = DEVICE(obj);
> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> index d3a2940..589bbe7 100644
> --- a/include/hw/qdev-core.h
> +++ b/include/hw/qdev-core.h
> @@ -365,7 +365,7 @@ extern int qdev_hotplug;
>  
>  char *qdev_get_dev_path(DeviceState *dev);
>  
> -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
>  
>  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
>                                Error **errp);
> diff --git a/monitor.c b/monitor.c
> index fa00594..f1031a1 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
>  static void peripheral_device_del_completion(ReadLineState *rs,
>                                               const char *str, size_t len)
>  {
> -    Object *peripheral;
> -    GSList *list = NULL, *item;
> +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> +    GSList *list, *item;
>  
> -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> -    if (peripheral == NULL) {
> +    list = qdev_build_hotpluggable_device_list(peripheral);
> +    if (!list) {
>          return;
>      }
>  
> -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> -                         &list);
> -
>      for (item = list; item; item = g_slist_next(item)) {
>          DeviceState *dev = item->data;
>  

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Luiz Capitulino]

On Wed, 26 Nov 2014 13:50:01 +0200
Marcel Apfelbaum <marcel.a@redhat.com> wrote:

> The commits:
>  - 6a1fa9f5 (monitor: add del completion for peripheral device)
>  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> 
> cause a QEMU crash when trying to use HMP device_del auto-completion.
> It can be easily reproduced by:
>     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> 
>     (qemu) device_del
>     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
>     Aborted (core dumped)
> 
> The root cause is qdev_build_hotpluggable_device_list going recursively over
> all peripherals and their children assuming all are devices. It doesn't work
> since PCI devices have at least on child which is a memory region (bus master).
> 
> Solved by observing that all devices appear as direct children of
> /machine/peripheral container. No need of going recursively
> over all the children.
> 
> Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>

Peter, can you apply this patch directly to master to avoid me a pull
request? Maybe it's a good idea to wait until tomorrow for more
reviewers though.

Marcel, thanks a lot for taking care of this!

> ---
>  hw/core/qdev.c         | 12 ++++++++++--
>  include/hw/qdev-core.h |  2 +-
>  monitor.c              | 11 ++++-------
>  3 files changed, 15 insertions(+), 10 deletions(-)
> 
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index 413b413..35fd00d 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
>      } while (class != object_class_by_name(TYPE_DEVICE));
>  }
>  
> -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
>  {
>      GSList **list = opaque;
>      DeviceState *dev = DEVICE(obj);
> @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
>          *list = g_slist_append(*list, dev);
>      }
>  
> -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
>      return 0;
>  }
>  
> +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> +{
> +    GSList *list = NULL;
> +
> +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> +
> +    return list;
> +}
> +
>  static bool device_get_realized(Object *obj, Error **errp)
>  {
>      DeviceState *dev = DEVICE(obj);
> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> index d3a2940..589bbe7 100644
> --- a/include/hw/qdev-core.h
> +++ b/include/hw/qdev-core.h
> @@ -365,7 +365,7 @@ extern int qdev_hotplug;
>  
>  char *qdev_get_dev_path(DeviceState *dev);
>  
> -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
>  
>  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
>                                Error **errp);
> diff --git a/monitor.c b/monitor.c
> index fa00594..f1031a1 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
>  static void peripheral_device_del_completion(ReadLineState *rs,
>                                               const char *str, size_t len)
>  {
> -    Object *peripheral;
> -    GSList *list = NULL, *item;
> +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> +    GSList *list, *item;
>  
> -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> -    if (peripheral == NULL) {
> +    list = qdev_build_hotpluggable_device_list(peripheral);
> +    if (!list) {
>          return;
>      }
>  
> -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> -                         &list);
> -
>      for (item = list; item; item = g_slist_next(item)) {
>          DeviceState *dev = item->data;
>  

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Peter Maydell]

On 26 November 2014 at 18:05, Luiz Capitulino <lcapitulino@redhat.com> wrote:
> Peter, can you apply this patch directly to master to avoid me a pull
> request? Maybe it's a good idea to wait until tomorrow for more
> reviewers though.

Sure. I'll apply it to master some time tomorrow afternoon I expect.

-- PMM

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Marcel Apfelbaum]

On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> On Wed, 26 Nov 2014 13:50:01 +0200
> Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> 
> > The commits:
> >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > 
> > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > It can be easily reproduced by:
> >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > 
> >     (qemu) device_del
> >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> >     Aborted (core dumped)
> > 
> > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > all peripherals and their children assuming all are devices. It doesn't work
> > since PCI devices have at least on child which is a memory region (bus master).
> > 
> > Solved by observing that all devices appear as direct children of
> > /machine/peripheral container. No need of going recursively
> > over all the children.
> > 
> > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> 
> Peter, can you apply this patch directly to master to avoid me a pull
> request? Maybe it's a good idea to wait until tomorrow for more
> reviewers though.
Yes, another review would be welcomed, especially a QOM reviewer.
 
> 
> Marcel, thanks a lot for taking care of this!
No problem, glad to do it.

I forgot to add:
Reported-by: Gal Hammer <ghammer@redhat.com>

Thanks,
Marcel
> 
> > ---
> >  hw/core/qdev.c         | 12 ++++++++++--
> >  include/hw/qdev-core.h |  2 +-
> >  monitor.c              | 11 ++++-------
> >  3 files changed, 15 insertions(+), 10 deletions(-)
> > 
> > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > index 413b413..35fd00d 100644
> > --- a/hw/core/qdev.c
> > +++ b/hw/core/qdev.c
> > @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
> >      } while (class != object_class_by_name(TYPE_DEVICE));
> >  }
> >  
> > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
> >  {
> >      GSList **list = opaque;
> >      DeviceState *dev = DEVICE(obj);
> > @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> >          *list = g_slist_append(*list, dev);
> >      }
> >  
> > -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
> >      return 0;
> >  }
> >  
> > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> > +{
> > +    GSList *list = NULL;
> > +
> > +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> > +
> > +    return list;
> > +}
> > +
> >  static bool device_get_realized(Object *obj, Error **errp)
> >  {
> >      DeviceState *dev = DEVICE(obj);
> > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > index d3a2940..589bbe7 100644
> > --- a/include/hw/qdev-core.h
> > +++ b/include/hw/qdev-core.h
> > @@ -365,7 +365,7 @@ extern int qdev_hotplug;
> >  
> >  char *qdev_get_dev_path(DeviceState *dev);
> >  
> > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
> >  
> >  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
> >                                Error **errp);
> > diff --git a/monitor.c b/monitor.c
> > index fa00594..f1031a1 100644
> > --- a/monitor.c
> > +++ b/monitor.c
> > @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
> >  static void peripheral_device_del_completion(ReadLineState *rs,
> >                                               const char *str, size_t len)
> >  {
> > -    Object *peripheral;
> > -    GSList *list = NULL, *item;
> > +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> > +    GSList *list, *item;
> >  
> > -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> > -    if (peripheral == NULL) {
> > +    list = qdev_build_hotpluggable_device_list(peripheral);
> > +    if (!list) {
> >          return;
> >      }
> >  
> > -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> > -                         &list);
> > -
> >      for (item = list; item; item = g_slist_next(item)) {
> >          DeviceState *dev = item->data;
> >  
> 

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Marcel Apfelbaum]

On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> On Wed, 26 Nov 2014 13:50:01 +0200
> Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> 
> > The commits:
> >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > 
> > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > It can be easily reproduced by:
> >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > 
> >     (qemu) device_del
> >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> >     Aborted (core dumped)
> > 
> > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > all peripherals and their children assuming all are devices. It doesn't work
> > since PCI devices have at least on child which is a memory region (bus master).
> > 
> > Solved by observing that all devices appear as direct children of
> > /machine/peripheral container. No need of going recursively
> > over all the children.
> > 
> > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> 
> Peter, can you apply this patch directly to master to avoid me a pull
> request? Maybe it's a good idea to wait until tomorrow for more
> reviewers though.
Speaking of reviewers, I double checked the patch and indeed it solves
the crash, but the original patch has another semantic error.
It looks for hot-pluggable device and not *hot-plugged* ones.

I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...

Thanks,
Marcel


> 
> Marcel, thanks a lot for taking care of this!
> 
> > ---
> >  hw/core/qdev.c         | 12 ++++++++++--
> >  include/hw/qdev-core.h |  2 +-
> >  monitor.c              | 11 ++++-------
> >  3 files changed, 15 insertions(+), 10 deletions(-)
> > 
> > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > index 413b413..35fd00d 100644
> > --- a/hw/core/qdev.c
> > +++ b/hw/core/qdev.c
> > @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
> >      } while (class != object_class_by_name(TYPE_DEVICE));
> >  }
> >  
> > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
> >  {
> >      GSList **list = opaque;
> >      DeviceState *dev = DEVICE(obj);
> > @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> >          *list = g_slist_append(*list, dev);
> >      }
> >  
> > -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
> >      return 0;
> >  }
> >  
> > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> > +{
> > +    GSList *list = NULL;
> > +
> > +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> > +
> > +    return list;
> > +}
> > +
> >  static bool device_get_realized(Object *obj, Error **errp)
> >  {
> >      DeviceState *dev = DEVICE(obj);
> > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > index d3a2940..589bbe7 100644
> > --- a/include/hw/qdev-core.h
> > +++ b/include/hw/qdev-core.h
> > @@ -365,7 +365,7 @@ extern int qdev_hotplug;
> >  
> >  char *qdev_get_dev_path(DeviceState *dev);
> >  
> > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
> >  
> >  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
> >                                Error **errp);
> > diff --git a/monitor.c b/monitor.c
> > index fa00594..f1031a1 100644
> > --- a/monitor.c
> > +++ b/monitor.c
> > @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
> >  static void peripheral_device_del_completion(ReadLineState *rs,
> >                                               const char *str, size_t len)
> >  {
> > -    Object *peripheral;
> > -    GSList *list = NULL, *item;
> > +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> > +    GSList *list, *item;
> >  
> > -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> > -    if (peripheral == NULL) {
> > +    list = qdev_build_hotpluggable_device_list(peripheral);
> > +    if (!list) {
> >          return;
> >      }
> >  
> > -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> > -                         &list);
> > -
> >      for (item = list; item; item = g_slist_next(item)) {
> >          DeviceState *dev = item->data;
> >  
> 
> 

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Marcel Apfelbaum]

On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > On Wed, 26 Nov 2014 13:50:01 +0200
> > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > 
> > > The commits:
> > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > 
> > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > It can be easily reproduced by:
> > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > 
> > >     (qemu) device_del
> > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > >     Aborted (core dumped)
> > > 
> > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > all peripherals and their children assuming all are devices. It doesn't work
> > > since PCI devices have at least on child which is a memory region (bus master).
> > > 
> > > Solved by observing that all devices appear as direct children of
> > > /machine/peripheral container. No need of going recursively
> > > over all the children.
> > > 
> > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > 
> > Peter, can you apply this patch directly to master to avoid me a pull
> > request? Maybe it's a good idea to wait until tomorrow for more
> > reviewers though.
> Speaking of reviewers, I double checked the patch and indeed it solves
> the crash, but the original patch has another semantic error.
> It looks for hot-pluggable device and not *hot-plugged* ones.
Thinking further, this is not fully true, we can hot-unplugged devices that weren't hot-plugged.
We have only a specific problem/bug with pci-2-pci bridge that is hotpluggable,
but can be hot-unpluged *only if* was hot-plugged. Other devices do not have this limitation.

> 
> I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
No need for a solution now, the above bug can wait for 2.3, the crash is
more important.
Please pull the patch for 2.2

Thanks,
Marcel

> 
> Thanks,
> Marcel
> 
> 
> > 
> > Marcel, thanks a lot for taking care of this!
> > 
> > > ---
> > >  hw/core/qdev.c         | 12 ++++++++++--
> > >  include/hw/qdev-core.h |  2 +-
> > >  monitor.c              | 11 ++++-------
> > >  3 files changed, 15 insertions(+), 10 deletions(-)
> > > 
> > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > > index 413b413..35fd00d 100644
> > > --- a/hw/core/qdev.c
> > > +++ b/hw/core/qdev.c
> > > @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
> > >      } while (class != object_class_by_name(TYPE_DEVICE));
> > >  }
> > >  
> > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
> > >  {
> > >      GSList **list = opaque;
> > >      DeviceState *dev = DEVICE(obj);
> > > @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > >          *list = g_slist_append(*list, dev);
> > >      }
> > >  
> > > -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
> > >      return 0;
> > >  }
> > >  
> > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> > > +{
> > > +    GSList *list = NULL;
> > > +
> > > +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> > > +
> > > +    return list;
> > > +}
> > > +
> > >  static bool device_get_realized(Object *obj, Error **errp)
> > >  {
> > >      DeviceState *dev = DEVICE(obj);
> > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > > index d3a2940..589bbe7 100644
> > > --- a/include/hw/qdev-core.h
> > > +++ b/include/hw/qdev-core.h
> > > @@ -365,7 +365,7 @@ extern int qdev_hotplug;
> > >  
> > >  char *qdev_get_dev_path(DeviceState *dev);
> > >  
> > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
> > >  
> > >  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
> > >                                Error **errp);
> > > diff --git a/monitor.c b/monitor.c
> > > index fa00594..f1031a1 100644
> > > --- a/monitor.c
> > > +++ b/monitor.c
> > > @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
> > >  static void peripheral_device_del_completion(ReadLineState *rs,
> > >                                               const char *str, size_t len)
> > >  {
> > > -    Object *peripheral;
> > > -    GSList *list = NULL, *item;
> > > +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> > > +    GSList *list, *item;
> > >  
> > > -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> > > -    if (peripheral == NULL) {
> > > +    list = qdev_build_hotpluggable_device_list(peripheral);
> > > +    if (!list) {
> > >          return;
> > >      }
> > >  
> > > -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> > > -                         &list);
> > > -
> > >      for (item = list; item; item = g_slist_next(item)) {
> > >          DeviceState *dev = item->data;
> > >  
> > 
> > 
> 
> 
> 
> 

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Zhu Guihua]

On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > On Wed, 26 Nov 2014 13:50:01 +0200
> > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > 
> > > The commits:
> > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > 
> > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > It can be easily reproduced by:
> > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > 
> > >     (qemu) device_del
> > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > >     Aborted (core dumped)
> > > 
> > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > all peripherals and their children assuming all are devices. It doesn't work
> > > since PCI devices have at least on child which is a memory region (bus master).
> > > 
> > > Solved by observing that all devices appear as direct children of
> > > /machine/peripheral container. No need of going recursively
> > > over all the children.
> > > 
> > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > 
> > Peter, can you apply this patch directly to master to avoid me a pull
> > request? Maybe it's a good idea to wait until tomorrow for more
> > reviewers though.
> Speaking of reviewers, I double checked the patch and indeed it solves
> the crash, but the original patch has another semantic error.
> It looks for hot-pluggable device and not *hot-plugged* ones.
> 
> I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
> 
Hi Marcel,

May you give an example for a hot-plugged but non-hot-pluggable device?

Regards,
Zhu

> Thanks,
> Marcel
> 
> 
> > 
> > Marcel, thanks a lot for taking care of this!
> > 
> > > ---
> > >  hw/core/qdev.c         | 12 ++++++++++--
> > >  include/hw/qdev-core.h |  2 +-
> > >  monitor.c              | 11 ++++-------
> > >  3 files changed, 15 insertions(+), 10 deletions(-)
> > > 
> > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > > index 413b413..35fd00d 100644
> > > --- a/hw/core/qdev.c
> > > +++ b/hw/core/qdev.c
> > > @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
> > >      } while (class != object_class_by_name(TYPE_DEVICE));
> > >  }
> > >  
> > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
> > >  {
> > >      GSList **list = opaque;
> > >      DeviceState *dev = DEVICE(obj);
> > > @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > >          *list = g_slist_append(*list, dev);
> > >      }
> > >  
> > > -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
> > >      return 0;
> > >  }
> > >  
> > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> > > +{
> > > +    GSList *list = NULL;
> > > +
> > > +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> > > +
> > > +    return list;
> > > +}
> > > +
> > >  static bool device_get_realized(Object *obj, Error **errp)
> > >  {
> > >      DeviceState *dev = DEVICE(obj);
> > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > > index d3a2940..589bbe7 100644
> > > --- a/include/hw/qdev-core.h
> > > +++ b/include/hw/qdev-core.h
> > > @@ -365,7 +365,7 @@ extern int qdev_hotplug;
> > >  
> > >  char *qdev_get_dev_path(DeviceState *dev);
> > >  
> > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
> > >  
> > >  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
> > >                                Error **errp);
> > > diff --git a/monitor.c b/monitor.c
> > > index fa00594..f1031a1 100644
> > > --- a/monitor.c
> > > +++ b/monitor.c
> > > @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
> > >  static void peripheral_device_del_completion(ReadLineState *rs,
> > >                                               const char *str, size_t len)
> > >  {
> > > -    Object *peripheral;
> > > -    GSList *list = NULL, *item;
> > > +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> > > +    GSList *list, *item;
> > >  
> > > -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> > > -    if (peripheral == NULL) {
> > > +    list = qdev_build_hotpluggable_device_list(peripheral);
> > > +    if (!list) {
> > >          return;
> > >      }
> > >  
> > > -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> > > -                         &list);
> > > -
> > >      for (item = list; item; item = g_slist_next(item)) {
> > >          DeviceState *dev = item->data;
> > >  
> > 
> > 
> 
> 
> 

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Marcel Apfelbaum]

On Thu, 2014-11-27 at 19:35 +0800, Zhu Guihua wrote:
> On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> > On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > > On Wed, 26 Nov 2014 13:50:01 +0200
> > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > 
> > > > The commits:
> > > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > > 
> > > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > > It can be easily reproduced by:
> > > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > > 
> > > >     (qemu) device_del
> > > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > > >     Aborted (core dumped)
> > > > 
> > > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > > all peripherals and their children assuming all are devices. It doesn't work
> > > > since PCI devices have at least on child which is a memory region (bus master).
> > > > 
> > > > Solved by observing that all devices appear as direct children of
> > > > /machine/peripheral container. No need of going recursively
> > > > over all the children.
> > > > 
> > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > > 
> > > Peter, can you apply this patch directly to master to avoid me a pull
> > > request? Maybe it's a good idea to wait until tomorrow for more
> > > reviewers though.
> > Speaking of reviewers, I double checked the patch and indeed it solves
> > the crash, but the original patch has another semantic error.
> > It looks for hot-pluggable device and not *hot-plugged* ones.
> > 
> > I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
> > 
> Hi Marcel,
> 
> May you give an example for a hot-plugged but non-hot-pluggable device?
I was talking about something different:
A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
This is not true for pci-2-pci device.

But this is another issue and can wait for 2.3.
So you patch was *almost* correct for looking hotpluggable devices,
the only problem we have is with pci-2-pci bridge (, and maybe with others that I don't know).

But for now, we should get the crash fix in and handle that separately
for 2.3. If anybody has a better idea, pleas advice.

Thanks,
Marcel


 

> 
> Regards,
> Zhu
> 
> > Thanks,
> > Marcel
> > 
> > 
> > > 
> > > Marcel, thanks a lot for taking care of this!
> > > 
> > > > ---
> > > >  hw/core/qdev.c         | 12 ++++++++++--
> > > >  include/hw/qdev-core.h |  2 +-
> > > >  monitor.c              | 11 ++++-------
> > > >  3 files changed, 15 insertions(+), 10 deletions(-)
> > > > 
> > > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > > > index 413b413..35fd00d 100644
> > > > --- a/hw/core/qdev.c
> > > > +++ b/hw/core/qdev.c
> > > > @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
> > > >      } while (class != object_class_by_name(TYPE_DEVICE));
> > > >  }
> > > >  
> > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
> > > >  {
> > > >      GSList **list = opaque;
> > > >      DeviceState *dev = DEVICE(obj);
> > > > @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > >          *list = g_slist_append(*list, dev);
> > > >      }
> > > >  
> > > > -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
> > > >      return 0;
> > > >  }
> > > >  
> > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> > > > +{
> > > > +    GSList *list = NULL;
> > > > +
> > > > +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> > > > +
> > > > +    return list;
> > > > +}
> > > > +
> > > >  static bool device_get_realized(Object *obj, Error **errp)
> > > >  {
> > > >      DeviceState *dev = DEVICE(obj);
> > > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > > > index d3a2940..589bbe7 100644
> > > > --- a/include/hw/qdev-core.h
> > > > +++ b/include/hw/qdev-core.h
> > > > @@ -365,7 +365,7 @@ extern int qdev_hotplug;
> > > >  
> > > >  char *qdev_get_dev_path(DeviceState *dev);
> > > >  
> > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
> > > >  
> > > >  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
> > > >                                Error **errp);
> > > > diff --git a/monitor.c b/monitor.c
> > > > index fa00594..f1031a1 100644
> > > > --- a/monitor.c
> > > > +++ b/monitor.c
> > > > @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
> > > >  static void peripheral_device_del_completion(ReadLineState *rs,
> > > >                                               const char *str, size_t len)
> > > >  {
> > > > -    Object *peripheral;
> > > > -    GSList *list = NULL, *item;
> > > > +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> > > > +    GSList *list, *item;
> > > >  
> > > > -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> > > > -    if (peripheral == NULL) {
> > > > +    list = qdev_build_hotpluggable_device_list(peripheral);
> > > > +    if (!list) {
> > > >          return;
> > > >      }
> > > >  
> > > > -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> > > > -                         &list);
> > > > -
> > > >      for (item = list; item; item = g_slist_next(item)) {
> > > >          DeviceState *dev = item->data;
> > > >  
> > > 
> > > 
> > 
> > 
> > 
> 
> 

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Zhu Guihua]

On Thu, 2014-11-27 at 13:41 +0200, Marcel Apfelbaum wrote:
> On Thu, 2014-11-27 at 19:35 +0800, Zhu Guihua wrote:
> > On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> > > On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > > > On Wed, 26 Nov 2014 13:50:01 +0200
> > > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > > 
> > > > > The commits:
> > > > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > > > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > > > 
> > > > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > > > It can be easily reproduced by:
> > > > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > > > 
> > > > >     (qemu) device_del
> > > > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > > > >     Aborted (core dumped)
> > > > > 
> > > > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > > > all peripherals and their children assuming all are devices. It doesn't work
> > > > > since PCI devices have at least on child which is a memory region (bus master).
> > > > > 
> > > > > Solved by observing that all devices appear as direct children of
> > > > > /machine/peripheral container. No need of going recursively
> > > > > over all the children.
> > > > > 
> > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > > > 
> > > > Peter, can you apply this patch directly to master to avoid me a pull
> > > > request? Maybe it's a good idea to wait until tomorrow for more
> > > > reviewers though.
> > > Speaking of reviewers, I double checked the patch and indeed it solves
> > > the crash, but the original patch has another semantic error.
> > > It looks for hot-pluggable device and not *hot-plugged* ones.
> > > 
> > > I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
> > > 
> > Hi Marcel,
> > 
> > May you give an example for a hot-plugged but non-hot-pluggable device?
> I was talking about something different:
> A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
> This is not true for pci-2-pci device.
> 

I'm sorry to misunderstand your mean.
Thanks for your explanation.

> But this is another issue and can wait for 2.3.
> So you patch was *almost* correct for looking hotpluggable devices,
> the only problem we have is with pci-2-pci bridge (, and maybe with others that I don't know).
> 

Yes, I test pci-bridge just now. The command "device_del" will cause
core dump. I will investigate other devices further.

And if I device_add pci-bridge without property chassis_nr, it will
causes core dumped too.

Regards,
Zhu

> But for now, we should get the crash fix in and handle that separately
> for 2.3. If anybody has a better idea, pleas advice.
> 
> Thanks,
> Marcel
> 
> 
>  
> 
> > 
> > Regards,
> > Zhu
> > 
> > > Thanks,
> > > Marcel
> > > 
> > > 
> > > > 
> > > > Marcel, thanks a lot for taking care of this!
> > > > 
> > > > > ---
> > > > >  hw/core/qdev.c         | 12 ++++++++++--
> > > > >  include/hw/qdev-core.h |  2 +-
> > > > >  monitor.c              | 11 ++++-------
> > > > >  3 files changed, 15 insertions(+), 10 deletions(-)
> > > > > 
> > > > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > > > > index 413b413..35fd00d 100644
> > > > > --- a/hw/core/qdev.c
> > > > > +++ b/hw/core/qdev.c
> > > > > @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
> > > > >      } while (class != object_class_by_name(TYPE_DEVICE));
> > > > >  }
> > > > >  
> > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > > +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
> > > > >  {
> > > > >      GSList **list = opaque;
> > > > >      DeviceState *dev = DEVICE(obj);
> > > > > @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > >          *list = g_slist_append(*list, dev);
> > > > >      }
> > > > >  
> > > > > -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
> > > > >      return 0;
> > > > >  }
> > > > >  
> > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> > > > > +{
> > > > > +    GSList *list = NULL;
> > > > > +
> > > > > +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> > > > > +
> > > > > +    return list;
> > > > > +}
> > > > > +
> > > > >  static bool device_get_realized(Object *obj, Error **errp)
> > > > >  {
> > > > >      DeviceState *dev = DEVICE(obj);
> > > > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > > > > index d3a2940..589bbe7 100644
> > > > > --- a/include/hw/qdev-core.h
> > > > > +++ b/include/hw/qdev-core.h
> > > > > @@ -365,7 +365,7 @@ extern int qdev_hotplug;
> > > > >  
> > > > >  char *qdev_get_dev_path(DeviceState *dev);
> > > > >  
> > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
> > > > >  
> > > > >  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
> > > > >                                Error **errp);
> > > > > diff --git a/monitor.c b/monitor.c
> > > > > index fa00594..f1031a1 100644
> > > > > --- a/monitor.c
> > > > > +++ b/monitor.c
> > > > > @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
> > > > >  static void peripheral_device_del_completion(ReadLineState *rs,
> > > > >                                               const char *str, size_t len)
> > > > >  {
> > > > > -    Object *peripheral;
> > > > > -    GSList *list = NULL, *item;
> > > > > +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> > > > > +    GSList *list, *item;
> > > > >  
> > > > > -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> > > > > -    if (peripheral == NULL) {
> > > > > +    list = qdev_build_hotpluggable_device_list(peripheral);
> > > > > +    if (!list) {
> > > > >          return;
> > > > >      }
> > > > >  
> > > > > -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> > > > > -                         &list);
> > > > > -
> > > > >      for (item = list; item; item = g_slist_next(item)) {
> > > > >          DeviceState *dev = item->data;
> > > > >  
> > > > 
> > > > 
> > > 
> > > 
> > > 
> > 
> > 
> 
> 
> 

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Marcel Apfelbaum]

On Thu, 2014-11-27 at 20:08 +0800, Zhu Guihua wrote:
> On Thu, 2014-11-27 at 13:41 +0200, Marcel Apfelbaum wrote:
> > On Thu, 2014-11-27 at 19:35 +0800, Zhu Guihua wrote:
> > > On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> > > > On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > > > > On Wed, 26 Nov 2014 13:50:01 +0200
> > > > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > > > 
> > > > > > The commits:
> > > > > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > > > > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > > > > 
> > > > > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > > > > It can be easily reproduced by:
> > > > > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > > > > 
> > > > > >     (qemu) device_del
> > > > > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > > > > >     Aborted (core dumped)
> > > > > > 
> > > > > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > > > > all peripherals and their children assuming all are devices. It doesn't work
> > > > > > since PCI devices have at least on child which is a memory region (bus master).
> > > > > > 
> > > > > > Solved by observing that all devices appear as direct children of
> > > > > > /machine/peripheral container. No need of going recursively
> > > > > > over all the children.
> > > > > > 
> > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > > > > 
> > > > > Peter, can you apply this patch directly to master to avoid me a pull
> > > > > request? Maybe it's a good idea to wait until tomorrow for more
> > > > > reviewers though.
> > > > Speaking of reviewers, I double checked the patch and indeed it solves
> > > > the crash, but the original patch has another semantic error.
> > > > It looks for hot-pluggable device and not *hot-plugged* ones.
> > > > 
> > > > I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
> > > > 
> > > Hi Marcel,
> > > 
> > > May you give an example for a hot-plugged but non-hot-pluggable device?
> > I was talking about something different:
> > A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
> > This is not true for pci-2-pci device.
> > 
> 
> I'm sorry to misunderstand your mean.
> Thanks for your explanation.
> 
> > But this is another issue and can wait for 2.3.
> > So you patch was *almost* correct for looking hotpluggable devices,
> > the only problem we have is with pci-2-pci bridge (, and maybe with others that I don't know).
> > 
> 
> Yes, I test pci-bridge just now. The command "device_del" will cause
> core dump. I will investigate other devices further.
After this patch you will not have a core dump.

> 
> And if I device_add pci-bridge without property chassis_nr, it will
> causes core dumped too.
Are you sure you use the master branch? This is not happening
Anyway, you didn't modify device_add, and this is not happening
on the latest master version.

Please correct me if I am wrong.

Thanks,
Marcel

> 
> Regards,
> Zhu
> 
> > But for now, we should get the crash fix in and handle that separately
> > for 2.3. If anybody has a better idea, pleas advice.
> > 
> > Thanks,
> > Marcel
> > 
> > 
> >  
> > 
> > > 
> > > Regards,
> > > Zhu
> > > 
> > > > Thanks,
> > > > Marcel
> > > > 
> > > > 
> > > > > 
> > > > > Marcel, thanks a lot for taking care of this!
> > > > > 
> > > > > > ---
> > > > > >  hw/core/qdev.c         | 12 ++++++++++--
> > > > > >  include/hw/qdev-core.h |  2 +-
> > > > > >  monitor.c              | 11 ++++-------
> > > > > >  3 files changed, 15 insertions(+), 10 deletions(-)
> > > > > > 
> > > > > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > > > > > index 413b413..35fd00d 100644
> > > > > > --- a/hw/core/qdev.c
> > > > > > +++ b/hw/core/qdev.c
> > > > > > @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
> > > > > >      } while (class != object_class_by_name(TYPE_DEVICE));
> > > > > >  }
> > > > > >  
> > > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > > > +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
> > > > > >  {
> > > > > >      GSList **list = opaque;
> > > > > >      DeviceState *dev = DEVICE(obj);
> > > > > > @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > > >          *list = g_slist_append(*list, dev);
> > > > > >      }
> > > > > >  
> > > > > > -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
> > > > > >      return 0;
> > > > > >  }
> > > > > >  
> > > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> > > > > > +{
> > > > > > +    GSList *list = NULL;
> > > > > > +
> > > > > > +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> > > > > > +
> > > > > > +    return list;
> > > > > > +}
> > > > > > +
> > > > > >  static bool device_get_realized(Object *obj, Error **errp)
> > > > > >  {
> > > > > >      DeviceState *dev = DEVICE(obj);
> > > > > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > > > > > index d3a2940..589bbe7 100644
> > > > > > --- a/include/hw/qdev-core.h
> > > > > > +++ b/include/hw/qdev-core.h
> > > > > > @@ -365,7 +365,7 @@ extern int qdev_hotplug;
> > > > > >  
> > > > > >  char *qdev_get_dev_path(DeviceState *dev);
> > > > > >  
> > > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> > > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
> > > > > >  
> > > > > >  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
> > > > > >                                Error **errp);
> > > > > > diff --git a/monitor.c b/monitor.c
> > > > > > index fa00594..f1031a1 100644
> > > > > > --- a/monitor.c
> > > > > > +++ b/monitor.c
> > > > > > @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
> > > > > >  static void peripheral_device_del_completion(ReadLineState *rs,
> > > > > >                                               const char *str, size_t len)
> > > > > >  {
> > > > > > -    Object *peripheral;
> > > > > > -    GSList *list = NULL, *item;
> > > > > > +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> > > > > > +    GSList *list, *item;
> > > > > >  
> > > > > > -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> > > > > > -    if (peripheral == NULL) {
> > > > > > +    list = qdev_build_hotpluggable_device_list(peripheral);
> > > > > > +    if (!list) {
> > > > > >          return;
> > > > > >      }
> > > > > >  
> > > > > > -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> > > > > > -                         &list);
> > > > > > -
> > > > > >      for (item = list; item; item = g_slist_next(item)) {
> > > > > >          DeviceState *dev = item->data;
> > > > > >  
> > > > > 
> > > > > 
> > > > 
> > > > 
> > > > 
> > > 
> > > 
> > 
> > 
> > 
> 
> 

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Igor Mammedov]

On Thu, 27 Nov 2014 13:41:07 +0200
Marcel Apfelbaum <marcel.a@redhat.com> wrote:

> On Thu, 2014-11-27 at 19:35 +0800, Zhu Guihua wrote:
> > On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> > > On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > > > On Wed, 26 Nov 2014 13:50:01 +0200
> > > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > > 
> > > > > The commits:
> > > > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > > > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > > > 
> > > > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > > > It can be easily reproduced by:
> > > > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > > > 
> > > > >     (qemu) device_del
> > > > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > > > >     Aborted (core dumped)
> > > > > 
> > > > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > > > all peripherals and their children assuming all are devices. It doesn't work
> > > > > since PCI devices have at least on child which is a memory region (bus master).
> > > > > 
> > > > > Solved by observing that all devices appear as direct children of
> > > > > /machine/peripheral container. No need of going recursively
> > > > > over all the children.
> > > > > 
> > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > > > 
> > > > Peter, can you apply this patch directly to master to avoid me a pull
> > > > request? Maybe it's a good idea to wait until tomorrow for more
> > > > reviewers though.
> > > Speaking of reviewers, I double checked the patch and indeed it solves
> > > the crash, but the original patch has another semantic error.
> > > It looks for hot-pluggable device and not *hot-plugged* ones.
> > > 
> > > I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
> > > 
> > Hi Marcel,
> > 
> > May you give an example for a hot-plugged but non-hot-pluggable device?
> I was talking about something different:
> A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
That's applicable to most of devices.

> This is not true for pci-2-pci device.
Do you have a reproducer?

> 
> But this is another issue and can wait for 2.3.
> So you patch was *almost* correct for looking hotpluggable devices,
> the only problem we have is with pci-2-pci bridge (, and maybe with others that I don't know).
> 
> But for now, we should get the crash fix in and handle that separately
> for 2.3. If anybody has a better idea, pleas advice.
> 
> Thanks,
> Marcel
> 
> 
>  
> 
> > 
> > Regards,
> > Zhu
> > 
> > > Thanks,
> > > Marcel
> > > 
> > > 
> > > > 
> > > > Marcel, thanks a lot for taking care of this!
> > > > 
> > > > > ---
> > > > >  hw/core/qdev.c         | 12 ++++++++++--
> > > > >  include/hw/qdev-core.h |  2 +-
> > > > >  monitor.c              | 11 ++++-------
> > > > >  3 files changed, 15 insertions(+), 10 deletions(-)
> > > > > 
> > > > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > > > > index 413b413..35fd00d 100644
> > > > > --- a/hw/core/qdev.c
> > > > > +++ b/hw/core/qdev.c
> > > > > @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
> > > > >      } while (class != object_class_by_name(TYPE_DEVICE));
> > > > >  }
> > > > >  
> > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > > +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
> > > > >  {
> > > > >      GSList **list = opaque;
> > > > >      DeviceState *dev = DEVICE(obj);
> > > > > @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > >          *list = g_slist_append(*list, dev);
> > > > >      }
> > > > >  
> > > > > -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
> > > > >      return 0;
> > > > >  }
> > > > >  
> > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> > > > > +{
> > > > > +    GSList *list = NULL;
> > > > > +
> > > > > +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> > > > > +
> > > > > +    return list;
> > > > > +}
> > > > > +
> > > > >  static bool device_get_realized(Object *obj, Error **errp)
> > > > >  {
> > > > >      DeviceState *dev = DEVICE(obj);
> > > > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > > > > index d3a2940..589bbe7 100644
> > > > > --- a/include/hw/qdev-core.h
> > > > > +++ b/include/hw/qdev-core.h
> > > > > @@ -365,7 +365,7 @@ extern int qdev_hotplug;
> > > > >  
> > > > >  char *qdev_get_dev_path(DeviceState *dev);
> > > > >  
> > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
> > > > >  
> > > > >  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
> > > > >                                Error **errp);
> > > > > diff --git a/monitor.c b/monitor.c
> > > > > index fa00594..f1031a1 100644
> > > > > --- a/monitor.c
> > > > > +++ b/monitor.c
> > > > > @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
> > > > >  static void peripheral_device_del_completion(ReadLineState *rs,
> > > > >                                               const char *str, size_t len)
> > > > >  {
> > > > > -    Object *peripheral;
> > > > > -    GSList *list = NULL, *item;
> > > > > +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> > > > > +    GSList *list, *item;
> > > > >  
> > > > > -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> > > > > -    if (peripheral == NULL) {
> > > > > +    list = qdev_build_hotpluggable_device_list(peripheral);
> > > > > +    if (!list) {
> > > > >          return;
> > > > >      }
> > > > >  
> > > > > -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> > > > > -                         &list);
> > > > > -
> > > > >      for (item = list; item; item = g_slist_next(item)) {
> > > > >          DeviceState *dev = item->data;
> > > > >  
> > > > 
> > > > 
> > > 
> > > 
> > > 
> > 
> > 
> 
> 
> 

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Marcel Apfelbaum]

On Thu, 2014-11-27 at 13:38 +0100, Igor Mammedov wrote:
> On Thu, 27 Nov 2014 13:41:07 +0200
> Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> 
> > On Thu, 2014-11-27 at 19:35 +0800, Zhu Guihua wrote:
> > > On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> > > > On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > > > > On Wed, 26 Nov 2014 13:50:01 +0200
> > > > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > > > 
> > > > > > The commits:
> > > > > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > > > > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > > > > 
> > > > > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > > > > It can be easily reproduced by:
> > > > > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > > > > 
> > > > > >     (qemu) device_del
> > > > > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > > > > >     Aborted (core dumped)
> > > > > > 
> > > > > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > > > > all peripherals and their children assuming all are devices. It doesn't work
> > > > > > since PCI devices have at least on child which is a memory region (bus master).
> > > > > > 
> > > > > > Solved by observing that all devices appear as direct children of
> > > > > > /machine/peripheral container. No need of going recursively
> > > > > > over all the children.
> > > > > > 
> > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > > > > 
> > > > > Peter, can you apply this patch directly to master to avoid me a pull
> > > > > request? Maybe it's a good idea to wait until tomorrow for more
> > > > > reviewers though.
> > > > Speaking of reviewers, I double checked the patch and indeed it solves
> > > > the crash, but the original patch has another semantic error.
> > > > It looks for hot-pluggable device and not *hot-plugged* ones.
> > > > 
> > > > I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
> > > > 
> > > Hi Marcel,
> > > 
> > > May you give an example for a hot-plugged but non-hot-pluggable device?
> > I was talking about something different:
> > A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
> That's applicable to most of devices.
> 
> > This is not true for pci-2-pci device.
> Do you have a reproducer?
Sure:
<qemu-bin> <img>  -device pci-bridge,chassis_nr=1,id=bridge

On monitor:
device_del bridge

And nothing happens since pci-2-pci can't be hot unplugged
The suspected reason is because it appears in ACPI tables. 

Thanks,
Marcel


> 
> > 
> > But this is another issue and can wait for 2.3.
> > So you patch was *almost* correct for looking hotpluggable devices,
> > the only problem we have is with pci-2-pci bridge (, and maybe with others that I don't know).
> > 
> > But for now, we should get the crash fix in and handle that separately
> > for 2.3. If anybody has a better idea, pleas advice.
> > 
> > Thanks,
> > Marcel
> > 
> > 
> >  
> > 
> > > 
> > > Regards,
> > > Zhu
> > > 
> > > > Thanks,
> > > > Marcel
> > > > 
> > > > 
> > > > > 
> > > > > Marcel, thanks a lot for taking care of this!
> > > > > 
> > > > > > ---
> > > > > >  hw/core/qdev.c         | 12 ++++++++++--
> > > > > >  include/hw/qdev-core.h |  2 +-
> > > > > >  monitor.c              | 11 ++++-------
> > > > > >  3 files changed, 15 insertions(+), 10 deletions(-)
> > > > > > 
> > > > > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > > > > > index 413b413..35fd00d 100644
> > > > > > --- a/hw/core/qdev.c
> > > > > > +++ b/hw/core/qdev.c
> > > > > > @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
> > > > > >      } while (class != object_class_by_name(TYPE_DEVICE));
> > > > > >  }
> > > > > >  
> > > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > > > +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
> > > > > >  {
> > > > > >      GSList **list = opaque;
> > > > > >      DeviceState *dev = DEVICE(obj);
> > > > > > @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > > >          *list = g_slist_append(*list, dev);
> > > > > >      }
> > > > > >  
> > > > > > -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
> > > > > >      return 0;
> > > > > >  }
> > > > > >  
> > > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> > > > > > +{
> > > > > > +    GSList *list = NULL;
> > > > > > +
> > > > > > +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> > > > > > +
> > > > > > +    return list;
> > > > > > +}
> > > > > > +
> > > > > >  static bool device_get_realized(Object *obj, Error **errp)
> > > > > >  {
> > > > > >      DeviceState *dev = DEVICE(obj);
> > > > > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > > > > > index d3a2940..589bbe7 100644
> > > > > > --- a/include/hw/qdev-core.h
> > > > > > +++ b/include/hw/qdev-core.h
> > > > > > @@ -365,7 +365,7 @@ extern int qdev_hotplug;
> > > > > >  
> > > > > >  char *qdev_get_dev_path(DeviceState *dev);
> > > > > >  
> > > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> > > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
> > > > > >  
> > > > > >  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
> > > > > >                                Error **errp);
> > > > > > diff --git a/monitor.c b/monitor.c
> > > > > > index fa00594..f1031a1 100644
> > > > > > --- a/monitor.c
> > > > > > +++ b/monitor.c
> > > > > > @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
> > > > > >  static void peripheral_device_del_completion(ReadLineState *rs,
> > > > > >                                               const char *str, size_t len)
> > > > > >  {
> > > > > > -    Object *peripheral;
> > > > > > -    GSList *list = NULL, *item;
> > > > > > +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> > > > > > +    GSList *list, *item;
> > > > > >  
> > > > > > -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> > > > > > -    if (peripheral == NULL) {
> > > > > > +    list = qdev_build_hotpluggable_device_list(peripheral);
> > > > > > +    if (!list) {
> > > > > >          return;
> > > > > >      }
> > > > > >  
> > > > > > -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> > > > > > -                         &list);
> > > > > > -
> > > > > >      for (item = list; item; item = g_slist_next(item)) {
> > > > > >          DeviceState *dev = item->data;
> > > > > >  
> > > > > 
> > > > > 
> > > > 
> > > > 
> > > > 
> > > 
> > > 
> > 
> > 
> > 
> 

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Luiz Capitulino]

On Thu, 27 Nov 2014 13:41:07 +0200
Marcel Apfelbaum <marcel.a@redhat.com> wrote:

> On Thu, 2014-11-27 at 19:35 +0800, Zhu Guihua wrote:
> > On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> > > On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > > > On Wed, 26 Nov 2014 13:50:01 +0200
> > > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > > 
> > > > > The commits:
> > > > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > > > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > > > 
> > > > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > > > It can be easily reproduced by:
> > > > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > > > 
> > > > >     (qemu) device_del
> > > > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > > > >     Aborted (core dumped)
> > > > > 
> > > > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > > > all peripherals and their children assuming all are devices. It doesn't work
> > > > > since PCI devices have at least on child which is a memory region (bus master).
> > > > > 
> > > > > Solved by observing that all devices appear as direct children of
> > > > > /machine/peripheral container. No need of going recursively
> > > > > over all the children.
> > > > > 
> > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > > > 
> > > > Peter, can you apply this patch directly to master to avoid me a pull
> > > > request? Maybe it's a good idea to wait until tomorrow for more
> > > > reviewers though.
> > > Speaking of reviewers, I double checked the patch and indeed it solves
> > > the crash, but the original patch has another semantic error.
> > > It looks for hot-pluggable device and not *hot-plugged* ones.
> > > 
> > > I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
> > > 
> > Hi Marcel,
> > 
> > May you give an example for a hot-plugged but non-hot-pluggable device?
> I was talking about something different:
> A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
> This is not true for pci-2-pci device.
> 
> But this is another issue and can wait for 2.3.

Agreed. We're on blockers phase right now. So, if it's not a blocker,
it can wait for -stable.

> So you patch was *almost* correct for looking hotpluggable devices,
> the only problem we have is with pci-2-pci bridge (, and maybe with others that I don't know).
> 
> But for now, we should get the crash fix in and handle that separately
> for 2.3. If anybody has a better idea, pleas advice.

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Peter Maydell]

On 27 November 2014 at 11:41, Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> I was talking about something different:
> A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
> This is not true for pci-2-pci device.
>
> But this is another issue and can wait for 2.3.
> So you patch was *almost* correct for looking hotpluggable devices,
> the only problem we have is with pci-2-pci bridge (, and maybe with others that I don't know).

So, to be clear, the effect of this is just that our autocompletion
will suggest a completion to the command which will fail if actually
executed, right? That doesn't sound very serious, so I would be happy
to postpone it to 2.3.

-- PMM

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Marcel Apfelbaum]

On Thu, 2014-11-27 at 14:13 +0000, Peter Maydell wrote:
> On 27 November 2014 at 11:41, Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > I was talking about something different:
> > A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
> > This is not true for pci-2-pci device.
> >
> > But this is another issue and can wait for 2.3.
> > So you patch was *almost* correct for looking hotpluggable devices,
> > the only problem we have is with pci-2-pci bridge (, and maybe with others that I don't know).
> 
> So, to be clear, the effect of this is just that our autocompletion
> will suggest a completion to the command which will fail if actually
> executed, right? That doesn't sound very serious, so I would be happy
> to postpone it to 2.3.
Correct. But only if this patch is applied, before this patch is a QEMU
crash.

Please pull it to solve the crash and we will deal with the other issues on 2.3

Thanks,
Marcel
> 
> -- PMM

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Peter Maydell]

On 26 November 2014 at 11:50, Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> The commits:
>  - 6a1fa9f5 (monitor: add del completion for peripheral device)
>  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
>
> cause a QEMU crash when trying to use HMP device_del auto-completion.
> It can be easily reproduced by:
>     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
>
>     (qemu) device_del
>     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
>     Aborted (core dumped)
>
> The root cause is qdev_build_hotpluggable_device_list going recursively over
> all peripherals and their children assuming all are devices. It doesn't work
> since PCI devices have at least on child which is a memory region (bus master).
>
> Solved by observing that all devices appear as direct children of
> /machine/peripheral container. No need of going recursively
> over all the children.
>
> Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>

Applied, thanks.

-- PMM

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Zhu Guihua]

On Thu, 2014-11-27 at 14:15 +0200, Marcel Apfelbaum wrote:
> On Thu, 2014-11-27 at 20:08 +0800, Zhu Guihua wrote:
> > On Thu, 2014-11-27 at 13:41 +0200, Marcel Apfelbaum wrote:
> > > On Thu, 2014-11-27 at 19:35 +0800, Zhu Guihua wrote:
> > > > On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> > > > > On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > > > > > On Wed, 26 Nov 2014 13:50:01 +0200
> > > > > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > > > > 
> > > > > > > The commits:
> > > > > > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > > > > > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > > > > > 
> > > > > > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > > > > > It can be easily reproduced by:
> > > > > > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > > > > > 
> > > > > > >     (qemu) device_del
> > > > > > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > > > > > >     Aborted (core dumped)
> > > > > > > 
> > > > > > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > > > > > all peripherals and their children assuming all are devices. It doesn't work
> > > > > > > since PCI devices have at least on child which is a memory region (bus master).
> > > > > > > 
> > > > > > > Solved by observing that all devices appear as direct children of
> > > > > > > /machine/peripheral container. No need of going recursively
> > > > > > > over all the children.
> > > > > > > 
> > > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > > > > > 
> > > > > > Peter, can you apply this patch directly to master to avoid me a pull
> > > > > > request? Maybe it's a good idea to wait until tomorrow for more
> > > > > > reviewers though.
> > > > > Speaking of reviewers, I double checked the patch and indeed it solves
> > > > > the crash, but the original patch has another semantic error.
> > > > > It looks for hot-pluggable device and not *hot-plugged* ones.
> > > > > 
> > > > > I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
> > > > > 
> > > > Hi Marcel,
> > > > 
> > > > May you give an example for a hot-plugged but non-hot-pluggable device?
> > > I was talking about something different:
> > > A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
> > > This is not true for pci-2-pci device.
> > > 
> > 
> > I'm sorry to misunderstand your mean.
> > Thanks for your explanation.
> > 
> > > But this is another issue and can wait for 2.3.
> > > So you patch was *almost* correct for looking hotpluggable devices,
> > > the only problem we have is with pci-2-pci bridge (, and maybe with others that I don't know).
> > > 
> > 
> > Yes, I test pci-bridge just now. The command "device_del" will cause
> > core dump. I will investigate other devices further.
> After this patch you will not have a core dump.
> 
> > 
> > And if I device_add pci-bridge without property chassis_nr, it will
> > causes core dumped too.
> Are you sure you use the master branch? This is not happening
> Anyway, you didn't modify device_add, and this is not happening
> on the latest master version.
> 
> Please correct me if I am wrong.

you are right, I am wrong. I used the master branch but not the latest
version yesterday.

regards,
Zhu

> 
> Thanks,
> Marcel
> 
> > 
> > Regards,
> > Zhu
> > 
> > > But for now, we should get the crash fix in and handle that separately
> > > for 2.3. If anybody has a better idea, pleas advice.
> > > 
> > > Thanks,
> > > Marcel
> > > 
> > > 
> > >  
> > > 
> > > > 
> > > > Regards,
> > > > Zhu
> > > > 
> > > > > Thanks,
> > > > > Marcel
> > > > > 
> > > > > 
> > > > > > 
> > > > > > Marcel, thanks a lot for taking care of this!
> > > > > > 
> > > > > > > ---
> > > > > > >  hw/core/qdev.c         | 12 ++++++++++--
> > > > > > >  include/hw/qdev-core.h |  2 +-
> > > > > > >  monitor.c              | 11 ++++-------
> > > > > > >  3 files changed, 15 insertions(+), 10 deletions(-)
> > > > > > > 
> > > > > > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > > > > > > index 413b413..35fd00d 100644
> > > > > > > --- a/hw/core/qdev.c
> > > > > > > +++ b/hw/core/qdev.c
> > > > > > > @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
> > > > > > >      } while (class != object_class_by_name(TYPE_DEVICE));
> > > > > > >  }
> > > > > > >  
> > > > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > > > > +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
> > > > > > >  {
> > > > > > >      GSList **list = opaque;
> > > > > > >      DeviceState *dev = DEVICE(obj);
> > > > > > > @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > > > >          *list = g_slist_append(*list, dev);
> > > > > > >      }
> > > > > > >  
> > > > > > > -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
> > > > > > >      return 0;
> > > > > > >  }
> > > > > > >  
> > > > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> > > > > > > +{
> > > > > > > +    GSList *list = NULL;
> > > > > > > +
> > > > > > > +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> > > > > > > +
> > > > > > > +    return list;
> > > > > > > +}
> > > > > > > +
> > > > > > >  static bool device_get_realized(Object *obj, Error **errp)
> > > > > > >  {
> > > > > > >      DeviceState *dev = DEVICE(obj);
> > > > > > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > > > > > > index d3a2940..589bbe7 100644
> > > > > > > --- a/include/hw/qdev-core.h
> > > > > > > +++ b/include/hw/qdev-core.h
> > > > > > > @@ -365,7 +365,7 @@ extern int qdev_hotplug;
> > > > > > >  
> > > > > > >  char *qdev_get_dev_path(DeviceState *dev);
> > > > > > >  
> > > > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> > > > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
> > > > > > >  
> > > > > > >  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
> > > > > > >                                Error **errp);
> > > > > > > diff --git a/monitor.c b/monitor.c
> > > > > > > index fa00594..f1031a1 100644
> > > > > > > --- a/monitor.c
> > > > > > > +++ b/monitor.c
> > > > > > > @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
> > > > > > >  static void peripheral_device_del_completion(ReadLineState *rs,
> > > > > > >                                               const char *str, size_t len)
> > > > > > >  {
> > > > > > > -    Object *peripheral;
> > > > > > > -    GSList *list = NULL, *item;
> > > > > > > +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> > > > > > > +    GSList *list, *item;
> > > > > > >  
> > > > > > > -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> > > > > > > -    if (peripheral == NULL) {
> > > > > > > +    list = qdev_build_hotpluggable_device_list(peripheral);
> > > > > > > +    if (!list) {
> > > > > > >          return;
> > > > > > >      }
> > > > > > >  
> > > > > > > -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> > > > > > > -                         &list);
> > > > > > > -
> > > > > > >      for (item = list; item; item = g_slist_next(item)) {
> > > > > > >          DeviceState *dev = item->data;
> > > > > > >  
> > > > > > 
> > > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > 
> > > > 
> > > 
> > > 
> > > 
> > 
> > 
> 
> 
> 

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Zhu Guihua]

On Thu, 2014-11-27 at 15:48 +0200, Marcel Apfelbaum wrote:
> On Thu, 2014-11-27 at 13:38 +0100, Igor Mammedov wrote:
> > On Thu, 27 Nov 2014 13:41:07 +0200
> > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > 
> > > On Thu, 2014-11-27 at 19:35 +0800, Zhu Guihua wrote:
> > > > On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> > > > > On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > > > > > On Wed, 26 Nov 2014 13:50:01 +0200
> > > > > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > > > > 
> > > > > > > The commits:
> > > > > > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > > > > > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > > > > > 
> > > > > > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > > > > > It can be easily reproduced by:
> > > > > > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > > > > > 
> > > > > > >     (qemu) device_del
> > > > > > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > > > > > >     Aborted (core dumped)
> > > > > > > 
> > > > > > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > > > > > all peripherals and their children assuming all are devices. It doesn't work
> > > > > > > since PCI devices have at least on child which is a memory region (bus master).
> > > > > > > 
> > > > > > > Solved by observing that all devices appear as direct children of
> > > > > > > /machine/peripheral container. No need of going recursively
> > > > > > > over all the children.
> > > > > > > 
> > > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > > > > > 
> > > > > > Peter, can you apply this patch directly to master to avoid me a pull
> > > > > > request? Maybe it's a good idea to wait until tomorrow for more
> > > > > > reviewers though.
> > > > > Speaking of reviewers, I double checked the patch and indeed it solves
> > > > > the crash, but the original patch has another semantic error.
> > > > > It looks for hot-pluggable device and not *hot-plugged* ones.
> > > > > 
> > > > > I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
> > > > > 
> > > > Hi Marcel,
> > > > 
> > > > May you give an example for a hot-plugged but non-hot-pluggable device?
> > > I was talking about something different:
> > > A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
> > That's applicable to most of devices.
> > 
> > > This is not true for pci-2-pci device.
> > Do you have a reproducer?
> Sure:
> <qemu-bin> <img>  -device pci-bridge,chassis_nr=1,id=bridge
> 

It is also not true for pc-dimm.
<qemu-bin> <img> -m 512,slots=10,maxmem=100G -object
memory-backend-ram,id=ram0,size=128M -device pc-dimm,id=d0,memdev=ram0

Regards,
Zhu

> On monitor:
> device_del bridge
> 
> And nothing happens since pci-2-pci can't be hot unplugged
> The suspected reason is because it appears in ACPI tables. 
> 
> Thanks,
> Marcel
> 
> 
> > 
> > > 
> > > But this is another issue and can wait for 2.3.
> > > So you patch was *almost* correct for looking hotpluggable devices,
> > > the only problem we have is with pci-2-pci bridge (, and maybe with others that I don't know).
> > > 
> > > But for now, we should get the crash fix in and handle that separately
> > > for 2.3. If anybody has a better idea, pleas advice.
> > > 
> > > Thanks,
> > > Marcel
> > > 
> > > 
> > >  
> > > 
> > > > 
> > > > Regards,
> > > > Zhu
> > > > 
> > > > > Thanks,
> > > > > Marcel
> > > > > 
> > > > > 
> > > > > > 
> > > > > > Marcel, thanks a lot for taking care of this!
> > > > > > 
> > > > > > > ---
> > > > > > >  hw/core/qdev.c         | 12 ++++++++++--
> > > > > > >  include/hw/qdev-core.h |  2 +-
> > > > > > >  monitor.c              | 11 ++++-------
> > > > > > >  3 files changed, 15 insertions(+), 10 deletions(-)
> > > > > > > 
> > > > > > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> > > > > > > index 413b413..35fd00d 100644
> > > > > > > --- a/hw/core/qdev.c
> > > > > > > +++ b/hw/core/qdev.c
> > > > > > > @@ -935,7 +935,7 @@ void qdev_alias_all_properties(DeviceState *target, Object *source)
> > > > > > >      } while (class != object_class_by_name(TYPE_DEVICE));
> > > > > > >  }
> > > > > > >  
> > > > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > > > > +static int qdev_add_hotpluggable_device(Object *obj, void *opaque)
> > > > > > >  {
> > > > > > >      GSList **list = opaque;
> > > > > > >      DeviceState *dev = DEVICE(obj);
> > > > > > > @@ -944,10 +944,18 @@ int qdev_build_hotpluggable_device_list(Object *obj, void *opaque)
> > > > > > >          *list = g_slist_append(*list, dev);
> > > > > > >      }
> > > > > > >  
> > > > > > > -    object_child_foreach(obj, qdev_build_hotpluggable_device_list, opaque);
> > > > > > >      return 0;
> > > > > > >  }
> > > > > > >  
> > > > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral)
> > > > > > > +{
> > > > > > > +    GSList *list = NULL;
> > > > > > > +
> > > > > > > +    object_child_foreach(peripheral, qdev_add_hotpluggable_device, &list);
> > > > > > > +
> > > > > > > +    return list;
> > > > > > > +}
> > > > > > > +
> > > > > > >  static bool device_get_realized(Object *obj, Error **errp)
> > > > > > >  {
> > > > > > >      DeviceState *dev = DEVICE(obj);
> > > > > > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > > > > > > index d3a2940..589bbe7 100644
> > > > > > > --- a/include/hw/qdev-core.h
> > > > > > > +++ b/include/hw/qdev-core.h
> > > > > > > @@ -365,7 +365,7 @@ extern int qdev_hotplug;
> > > > > > >  
> > > > > > >  char *qdev_get_dev_path(DeviceState *dev);
> > > > > > >  
> > > > > > > -int qdev_build_hotpluggable_device_list(Object *obj, void *opaque);
> > > > > > > +GSList *qdev_build_hotpluggable_device_list(Object *peripheral);
> > > > > > >  
> > > > > > >  void qbus_set_hotplug_handler(BusState *bus, DeviceState *handler,
> > > > > > >                                Error **errp);
> > > > > > > diff --git a/monitor.c b/monitor.c
> > > > > > > index fa00594..f1031a1 100644
> > > > > > > --- a/monitor.c
> > > > > > > +++ b/monitor.c
> > > > > > > @@ -4321,17 +4321,14 @@ void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
> > > > > > >  static void peripheral_device_del_completion(ReadLineState *rs,
> > > > > > >                                               const char *str, size_t len)
> > > > > > >  {
> > > > > > > -    Object *peripheral;
> > > > > > > -    GSList *list = NULL, *item;
> > > > > > > +    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
> > > > > > > +    GSList *list, *item;
> > > > > > >  
> > > > > > > -    peripheral = object_resolve_path("/machine/peripheral/", NULL);
> > > > > > > -    if (peripheral == NULL) {
> > > > > > > +    list = qdev_build_hotpluggable_device_list(peripheral);
> > > > > > > +    if (!list) {
> > > > > > >          return;
> > > > > > >      }
> > > > > > >  
> > > > > > > -    object_child_foreach(peripheral, qdev_build_hotpluggable_device_list,
> > > > > > > -                         &list);
> > > > > > > -
> > > > > > >      for (item = list; item; item = g_slist_next(item)) {
> > > > > > >          DeviceState *dev = item->data;
> > > > > > >  
> > > > > > 
> > > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > 
> > > > 
> > > 
> > > 
> > > 
> > 
> 
> 
> 

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Marcel Apfelbaum]

On Fri, 2014-11-28 at 09:50 +0800, Zhu Guihua wrote:
> On Thu, 2014-11-27 at 15:48 +0200, Marcel Apfelbaum wrote:
> > On Thu, 2014-11-27 at 13:38 +0100, Igor Mammedov wrote:
> > > On Thu, 27 Nov 2014 13:41:07 +0200
> > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > 
> > > > On Thu, 2014-11-27 at 19:35 +0800, Zhu Guihua wrote:
> > > > > On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> > > > > > On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > > > > > > On Wed, 26 Nov 2014 13:50:01 +0200
> > > > > > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > > > > > 
> > > > > > > > The commits:
> > > > > > > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > > > > > > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > > > > > > 
> > > > > > > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > > > > > > It can be easily reproduced by:
> > > > > > > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > > > > > > 
> > > > > > > >     (qemu) device_del
> > > > > > > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > > > > > > >     Aborted (core dumped)
> > > > > > > > 
> > > > > > > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > > > > > > all peripherals and their children assuming all are devices. It doesn't work
> > > > > > > > since PCI devices have at least on child which is a memory region (bus master).
> > > > > > > > 
> > > > > > > > Solved by observing that all devices appear as direct children of
> > > > > > > > /machine/peripheral container. No need of going recursively
> > > > > > > > over all the children.
> > > > > > > > 
> > > > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > > > > > > 
> > > > > > > Peter, can you apply this patch directly to master to avoid me a pull
> > > > > > > request? Maybe it's a good idea to wait until tomorrow for more
> > > > > > > reviewers though.
> > > > > > Speaking of reviewers, I double checked the patch and indeed it solves
> > > > > > the crash, but the original patch has another semantic error.
> > > > > > It looks for hot-pluggable device and not *hot-plugged* ones.
> > > > > > 
> > > > > > I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
> > > > > > 
> > > > > Hi Marcel,
> > > > > 
> > > > > May you give an example for a hot-plugged but non-hot-pluggable device?
> > > > I was talking about something different:
> > > > A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
> > > That's applicable to most of devices.
> > > 
> > > > This is not true for pci-2-pci device.
> > > Do you have a reproducer?
> > Sure:
> > <qemu-bin> <img>  -device pci-bridge,chassis_nr=1,id=bridge
> > 
> 
> It is also not true for pc-dimm.
> <qemu-bin> <img> -m 512,slots=10,maxmem=100G -object
> memory-backend-ram,id=ram0,size=128M -device pc-dimm,id=d0,memdev=ram0

Thanks for finding it!
I'll try to add a "can be hot-unplugged" flag whose default value
is "hotpluggable".
This can be overridden by sub-classes to meet their needs.

2.3 material, of course

Thanks,
Marcel
 
[...]

Re: [Qemu-devel] [PATCH] hmp: fix regression of HMP device_del auto-completion

[Igor Mammedov]

On Fri, 28 Nov 2014 07:53:41 +0200
Marcel Apfelbaum <marcel.a@redhat.com> wrote:

> On Fri, 2014-11-28 at 09:50 +0800, Zhu Guihua wrote:
> > On Thu, 2014-11-27 at 15:48 +0200, Marcel Apfelbaum wrote:
> > > On Thu, 2014-11-27 at 13:38 +0100, Igor Mammedov wrote:
> > > > On Thu, 27 Nov 2014 13:41:07 +0200
> > > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > > 
> > > > > On Thu, 2014-11-27 at 19:35 +0800, Zhu Guihua wrote:
> > > > > > On Thu, 2014-11-27 at 13:11 +0200, Marcel Apfelbaum wrote:
> > > > > > > On Wed, 2014-11-26 at 13:05 -0500, Luiz Capitulino wrote:
> > > > > > > > On Wed, 26 Nov 2014 13:50:01 +0200
> > > > > > > > Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> > > > > > > > 
> > > > > > > > > The commits:
> > > > > > > > >  - 6a1fa9f5 (monitor: add del completion for peripheral device)
> > > > > > > > >  - 66e56b13 (qdev: add qdev_build_hotpluggable_device_list helper)
> > > > > > > > > 
> > > > > > > > > cause a QEMU crash when trying to use HMP device_del auto-completion.
> > > > > > > > > It can be easily reproduced by:
> > > > > > > > >     <qemu-bin> -enable-kvm  ~/images/fedora.qcow2 -monitor stdio -device virtio-net-pci,id=vnet
> > > > > > > > > 
> > > > > > > > >     (qemu) device_del
> > > > > > > > >     /home/mapfelba/git/upstream/qemu/hw/core/qdev.c:941:qdev_build_hotpluggable_device_list: Object 0x7f6ce04e4fe0 is not an instance of type device
> > > > > > > > >     Aborted (core dumped)
> > > > > > > > > 
> > > > > > > > > The root cause is qdev_build_hotpluggable_device_list going recursively over
> > > > > > > > > all peripherals and their children assuming all are devices. It doesn't work
> > > > > > > > > since PCI devices have at least on child which is a memory region (bus master).
> > > > > > > > > 
> > > > > > > > > Solved by observing that all devices appear as direct children of
> > > > > > > > > /machine/peripheral container. No need of going recursively
> > > > > > > > > over all the children.
> > > > > > > > > 
> > > > > > > > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> > > > > > > > 
> > > > > > > > Peter, can you apply this patch directly to master to avoid me a pull
> > > > > > > > request? Maybe it's a good idea to wait until tomorrow for more
> > > > > > > > reviewers though.
> > > > > > > Speaking of reviewers, I double checked the patch and indeed it solves
> > > > > > > the crash, but the original patch has another semantic error.
> > > > > > > It looks for hot-pluggable device and not *hot-plugged* ones.
> > > > > > > 
> > > > > > > I'll try to come with a solution fast. It should be a "hot-plugged" property somewhere...
> > > > > > > 
> > > > > > Hi Marcel,
> > > > > > 
> > > > > > May you give an example for a hot-plugged but non-hot-pluggable device?
> > > > > I was talking about something different:
> > > > > A hot-pluggable device that was not hot-plugged is assumed to be hot-unpluggable.
> > > > That's applicable to most of devices.
> > > > 
> > > > > This is not true for pci-2-pci device.
> > > > Do you have a reproducer?
> > > Sure:
> > > <qemu-bin> <img>  -device pci-bridge,chassis_nr=1,id=bridge
> > > 
> > 
> > It is also not true for pc-dimm.
> > <qemu-bin> <img> -m 512,slots=10,maxmem=100G -object
> > memory-backend-ram,id=ram0,size=128M -device pc-dimm,id=d0,memdev=ram0
It's just that unplug is not implemented for pc-dimm,
but eventually it should be unpluggable.

> 
> Thanks for finding it!
> I'll try to add a "can be hot-unplugged" flag whose default value
> is "hotpluggable".
> This can be overridden by sub-classes to meet their needs.
> 
> 2.3 material, of course
> 
> Thanks,
> Marcel
>  
> [...]
>