Re: [Qemu-devel] [PATCHv7 3/6] fw_cfg: switch fw_cfg_find() to locate the fw_cfg device by type rather than path

[Mark Cave-Ayland]

On 03/07/17 10:42, Igor Mammedov wrote:
> On Thu, 29 Jun 2017 15:07:17 +0100
> Mark Cave-Ayland <address@hidden> wrote:
> 
>> This will enable the fw_cfg device to be placed anywhere within the QOM tree
>> regardless of its machine location.
>>
>> Signed-off-by: Mark Cave-Ayland <address@hidden>
>> ---
>>  hw/nvram/fw_cfg.c |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
>> index 99bdbc2..0fe7404 100644
>> --- a/hw/nvram/fw_cfg.c
>> +++ b/hw/nvram/fw_cfg.c
>> @@ -1017,7 +1017,7 @@ FWCfgState *fw_cfg_init_mem(hwaddr ctl_addr, hwaddr 
>> data_addr)
>>  
>>  FWCfgState *fw_cfg_find(void)
>>  {
>> -    return FW_CFG(object_resolve_path(FW_CFG_PATH, NULL));
>> +    return FW_CFG(object_resolve_path_type("", TYPE_FW_CFG, NULL));
> I insist on using ambiguous argument
> 
> see why it's needed
>  https://www.mail-archive.com/address@hidden/msg460692.html

Yes I did take into account your previous comment about the ambiguous
argument, but with the fw_cfg_unattached_at_realize() check added in the
v7 patchset, it is actually impossible to realize more than one fw_cfg
device, and at realize time that device must have been linked as a child
device to a parent device.

Hence it should be impossible for the above situation where more than
one fw_cfg device can exist in the QOM tree to occur. Have I missed
something in the logic which would prevent this from happening?


ATB,

Mark.