Re: [Qemu-devel] [RFC PATCH V8 01/15] qdev : add a maximum device allowed field for the bus.

[Anthony Liguori <aliguori@us.ibm.com>]

fred.konrad@greensocs.com writes:

> From: KONRAD Frederic <fred.konrad@greensocs.com>
>
> Add a max_dev field to BusState to specify the maximum amount of devices allowed
> on the bus ( have no effect if max_dev=0 )
>
> Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
> ---
>  hw/qdev-core.h    |  2 ++
>  hw/qdev-monitor.c | 11 +++++++++++
>  2 files changed, 13 insertions(+)
>
> diff --git a/hw/qdev-core.h b/hw/qdev-core.h
> index d672cca..af909b9 100644
> --- a/hw/qdev-core.h
> +++ b/hw/qdev-core.h
> @@ -104,6 +104,8 @@ struct BusState {
>      const char *name;
>      int allow_hotplug;
>      int max_index;
> +    /* maximum devices allowed on the bus, 0 : no limit. */
> +    int max_dev;
>      QTAILQ_HEAD(ChildrenHead, BusChild) children;
>      QLIST_ENTRY(BusState) sibling;
>  };
> diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
> index a1b4d6a..7a9d275 100644
> --- a/hw/qdev-monitor.c
> +++ b/hw/qdev-monitor.c
> @@ -292,6 +292,17 @@ static BusState *qbus_find_recursive(BusState *bus, const char *name,
>      if (bus_typename && !object_dynamic_cast(OBJECT(bus), bus_typename)) {
>          match = 0;
>      }
> +    if ((bus->max_dev != 0) && (bus->max_dev <= bus->max_index)) {
> +        if (name != NULL) {
> +            /* bus was explicitly specified : return an error. */
> +            qerror_report(ERROR_CLASS_GENERIC_ERROR, "Bus '%s' is full",
> +                          bus->name);
> +            return NULL;
> +        } else {
> +            /* bus was not specified : try to find another one. */
> +            match = 0;
> +        }
> +    }
>      if (match) {
>          return bus;
>      }

Nice change, but I wonder if this should be a class property instead of
an object property?  Would different objects of the same class ever set
this differently?

Regards,

Anthony Liguori

> -- 
> 1.7.11.7