[Qemu-devel] Re: [PATCHv4 1/2] qdev: add bit property type

[Michael S. Tsirkin]

On Mon, Jan 04, 2010 at 03:22:36PM +0100, Gerd Hoffmann wrote:
> On 12/24/09 13:43, Michael S. Tsirkin wrote:
>> This adds "bit" property type, which is a boolean stored in a 32 bit
>> integer field, with legal values on and off.  Will be used by virtio for
>> feature bits.
>
>> +static void *qdev_bit_prop_ptr(DeviceState *dev, Property *prop)
>> +{
>> +    void *ptr = dev;
>> +    assert(prop->info->type == PROP_TYPE_BIT);
>> +    ptr += prop->offset / 32;
>> +    return ptr;
>> +}
>
> I don't like that idea.  IMHO prop->offset should be specified in bytes  
> no matter what the property is.  Better add a new prop->bitnr field to  
> specify which bit of the 32bit word should be toggled.  Then you don't  
> need this function in the first place.
>
> cheers,
>   Gerd

OK, I reworked the patches in this way.