Re: [Qemu-devel] [PATCH v1 06/11] pc-dimm: don't allow to access "size" before the device was realized

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 14 Jun 2018 16:10:14 +0200
David Hildenbrand <david@redhat.com> wrote:

> On 14.06.2018 15:24, Igor Mammedov wrote:
> > On Wed, 13 Jun 2018 16:03:35 +0200
> > David Hildenbrand <david@redhat.com> wrote:
> >   
> >> On 13.06.2018 14:56, Igor Mammedov wrote:  
> >>> On Mon, 11 Jun 2018 14:16:50 +0200
> >>> David Hildenbrand <david@redhat.com> wrote:
> >>>     
> >>>> "size" should not be queried before the device was realized. Let' make
> >>>> that explicit.
> >>>>
> >>>> Signed-off-by: David Hildenbrand <david@redhat.com>    
> >>> It's generic property getter, it should work even before realize is called.    
> >>
> >> That's the point, as we can see in NVDIMM code , it is *not* a generic
> >> property getter.  
> > it is added by 
> >     object_property_add(obj, PC_DIMM_SIZE_PROP, "uint64", pc_dimm_get_size,      
> >                         NULL, NULL, NULL, &error_abort); 
> > hence it's generic QOM property as opposed to memory device class specific callbacks.
> >   
> >>  
> >>>
> >>> if issues described in 5/11 are properly fixed, this patch won't be needed.
> >>>
> >>> So drop this patch
> >>>
> >>>     
> >>>> ---
> >>>>  hw/mem/pc-dimm.c | 6 ++++++
> >>>>  1 file changed, 6 insertions(+)
> >>>>
> >>>> diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> >>>> index 86fbcf2d0c..5294734529 100644
> >>>> --- a/hw/mem/pc-dimm.c
> >>>> +++ b/hw/mem/pc-dimm.c
> >>>> @@ -166,6 +166,12 @@ static void pc_dimm_get_size(Object *obj, Visitor *v, const char *name,
> >>>>      PCDIMMDevice *dimm = PC_DIMM(obj);
> >>>>      PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(obj);
> >>>>  
> >>>> +    if (!DEVICE(obj)->realized) {
> >>>> +        error_setg(errp, "Property \"%s\" not accessible before realized",
> >>>> +                   name);
> >>>> +        return;
> >>>> +    }
> >>>> +
> >>>>      mr = ddc->get_memory_region(dimm, errp);  
> > just make ddc->get_memory_region return error if 'memdev' isn't set yet
> > and add local_error handling here as proper property assessor should do.
> >   
> 
> Does not help for NVDIMM.
NVDIMM should be fixed as it's broken now and works just by accident.
I don't like tailoring infrastructure changes to a particular broken
device especially when the later could be made to work within current
framework.