Re: [Qemu-devel] [PATCH 09/13] block: Add 'runtime_opts' and 'mutable_opts' fields to BlockDriver

[Alberto Garcia <berto@igalia.com>]

On Fri 01 Mar 2019 01:56:42 PM CET, Kevin Wolf wrote:
>> >> >> diff --git a/include/block/block_int.h b/include/block/block_int.h
>> >> >> index fd0e88d17a..e680dda86b 100644
>> >> >> --- a/include/block/block_int.h
>> >> >> +++ b/include/block/block_int.h
>> >> >> @@ -345,6 +345,13 @@ struct BlockDriver {
>> >> >>  
>> >> >>      /* List of options for creating images, terminated by name == NULL */
>> >> >>      QemuOptsList *create_opts;
>> >> >> +    /* Runtime options for a block device, terminated by name == NULL */
>> >> >> +    QemuOptsList *runtime_opts;
>> >> >
>> >> > I'm not sure if using a QemuOptsList here is a good idea. Currently,
>> >> > we use QemuOptsLists for most options, but there are some drivers that
>> >> > use it only for part of their options, or not at all, using direct
>> >> > QDict accesses or QAPI objects for the rest.
>> >> 
>> >> My intention was to avoid having two separate lists with the runtime
>> >> options of a driver. For this feature we really need that list to
>> >> contain all options, otherwise there's no way to know whether a missing
>> >> option is really missing or if it doesn't exist in the first place.
>> >
>> > Yes, I understand your intention and the requirement. My point is just
>> > that the existing QemuOptsLists are often _not_ complete, so they
>> > can't fulfill the requirement.
>> 
>> Perhaps a new data structure with a list of runtime options and whether
>> they can be resetted to their default value or not.
>
> Basically just an array that contains names and bools, right? I think
> that would work.

Yes exactly. My concern is that the array has to be updated by hand
every time a new option is added to the driver, so they could easily be
out of sync.

Berto