Re: [Qemu-devel] [PATCH] hw/sparc64/sun4u: Fix introspection by converting prom instance_init to realize

[Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>]

On 05/04/18 10:32, Thomas Huth wrote:

> The instance_init function of devices should always succeed to be able
> to introspect the device. However, the instance_init function of the
> "openprom" device can currently fail, for example like this:
> 
> $ echo "{'execute':'qmp_capabilities'}"\
>         "{'execute':'device-list-properties',"\
>         " 'arguments':{'typename':'openprom'}}" \
>         | sparc64-softmmu/qemu-system-sparc64 -M sun4v,accel=qtest -qmp stdio
> {"QMP": {"version": {"qemu": {"micro": 91, "minor": 11, "major": 2},
>   "package": "build-all"}, "capabilities": []}}
> {"return": {}}
> RAMBlock "sun4u.prom" already registered, abort!
> Aborted (core dumped)
> 
> This should not happen. Fix this problem by moving the affected code from
> instance_init into a realize function instead.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>   hw/sparc64/sun4u.c | 18 ++++++++++++------
>   1 file changed, 12 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/sparc64/sun4u.c b/hw/sparc64/sun4u.c
> index 2044a52..d62f5a2 100644
> --- a/hw/sparc64/sun4u.c
> +++ b/hw/sparc64/sun4u.c
> @@ -425,13 +425,19 @@ static void prom_init(hwaddr addr, const char *bios_name)
>       }
>   }
>   
> -static void prom_init1(Object *obj)
> +static void prom_realize(DeviceState *ds, Error **errp)
>   {
> -    PROMState *s = OPENPROM(obj);
> -    SysBusDevice *dev = SYS_BUS_DEVICE(obj);
> +    PROMState *s = OPENPROM(ds);
> +    SysBusDevice *dev = SYS_BUS_DEVICE(ds);
> +    Error *local_err = NULL;
> +
> +    memory_region_init_ram_nomigrate(&s->prom, OBJECT(ds), "sun4u.prom",
> +                                     PROM_SIZE_MAX, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
>   
> -    memory_region_init_ram_nomigrate(&s->prom, obj, "sun4u.prom", PROM_SIZE_MAX,
> -                           &error_fatal);
>       vmstate_register_ram_global(&s->prom);
>       memory_region_set_readonly(&s->prom, true);
>       sysbus_init_mmio(dev, &s->prom);
> @@ -446,6 +452,7 @@ static void prom_class_init(ObjectClass *klass, void *data)
>       DeviceClass *dc = DEVICE_CLASS(klass);
>   
>       dc->props = prom_properties;
> +    dc->realize = prom_realize;
>   }
>   
>   static const TypeInfo prom_info = {
> @@ -453,7 +460,6 @@ static const TypeInfo prom_info = {
>       .parent        = TYPE_SYS_BUS_DEVICE,
>       .instance_size = sizeof(PROMState),
>       .class_init    = prom_class_init,
> -    .instance_init = prom_init1,
>   };

Looks good to me:

Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

I thought this would have been caught by the device introspect test, or 
is this something you've found whilst trying to add sun4v to the list of 
machines to include in the test?


ATB,

Mark.