Re: [Qemu-devel] Re: [RFC] QCFG: a new mechanism to replace QemuOpts and option handling

[Kevin Wolf <kwolf@redhat.com>]

Am 15.03.2011 14:37, schrieb Anthony Liguori:
> On 03/15/2011 06:21 AM, Kevin Wolf wrote:
>> Am 14.03.2011 18:48, schrieb Anthony Liguori:
>>> I've got a spec written up at http://wiki.qemu.org/Features/QCFG.
>>> Initial code is in my QAPI tree.
>> One question about a small detail on this wiki page:
>>
>>> typedef struct BlockdevConfig {
>>>      char * file;
>>>      struct BlockdevConfig * backing_file;
>>>
>>>      struct BlockdevConfig * next;
>>> } BlockdevConfig;
>> What is the 'next' pointer used for,
> 
> This is a standard part of QAPI.  All types get a next pointer added 
> such that we can support lists of complex types.

Only a single list for each object.

>>   are you going to store a list of
>> all -blockdev options used? And why isn't it a QLIST or something?
> 
> Two reasons.  QLIST requires another type for the head of the list which 
> would complicate things overall.  Second is that these types are part of 
> the libqmp interface and I didn't want to force qemu-queue on any 
> consumer of libqmp.

And now you force existing qemu code to go back to open coded lists,
which is arguably a step backwards. I don't think this is any better
than forcing the (non-existent) users of libqmp to include one
additional header file.

Kevin