Re: [PATCH v3 29/30] vl: QAPIfy -object

[Eric Blake]

On 3/8/21 10:54 AM, Kevin Wolf wrote:
> This switches the system emulator from a QemuOpts-based parser for
> -object to user_creatable_parse_str() which uses a keyval parser and
> enforces the QAPI schema.
> 
> Apart from being a cleanup, this makes non-scalar properties accessible.
> 
> This adopts a similar model as -blockdev uses: When parsing the option,
> create the ObjectOptions and queue them. At the later point where we
> used to create objects for the collected QemuOpts, the ObjectOptions
> queue is processed instead.
> 
> A complication compared to -blockdev is that object definitions are
> supported in -readconfig and -writeconfig.
> 
> After this patch, -readconfig still works, though it still goes through
> the QemuOpts parser, which means that improvements like non-scalar
> properties are still not available in config files.
> 
> -writeconfig stops working for -object. Tough luck. It has never
> supported all options (not even the common ones), so supporting one less
> isn't the end of the world. As object definitions from -readconfig still
> go through QemuOpts, they are still included in -writeconfig output,
> which at least prevents destroying your existing configuration when you
> just wanted to add another option.

Maybe worth a tweak to this paragraph now that b979c931 has landed
formally deprecating -writeconfig (all the more reason we don't care
about it).

> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> Acked-by: Peter Krempa <pkrempa@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>

R-b stands either way.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org