Re: About '-readconfig' [Was: Re: [PULL 27/29] vl: deprecate -writeconfig]

[Paolo Bonzini]

On 01/03/21 17:03, Kashyap Chamarthy wrote:
> On Fri, Feb 26, 2021 at 09:05:24AM +0100, Paolo Bonzini wrote:
> > The functionality of -writeconfig is limited and the code
> > does not even try to detect cases where it prints incorrect
> > syntax (for example if values have a quote in them, since
> > qemu_config_parse does not support any kind of escaping)
> > so remove it.
> >
> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> > ---
> >   docs/system/deprecated.rst | 7 +++++++
> >   qemu-options.hx            | 7 +------
> >   softmmu/vl.c               | 1 +
> >   3 files changed, 9 insertions(+), 6 deletions(-)
>
> [...]
>
> Hi,
>
> Sorry, I'm coming very late[1] to the discussion.  Will there be a
> replacement for '-readconfig'?

-readconfig is not being deprecated, there will be some code new to 
integrate it with the changes I'm planning to option parsing.

Paolo

> I agree with Gerd's comment[2] in the last year's thread (I missed to
> notice at that time) about '-readconfig' being useful.  I'm familiar
> with least one hosting provider who uses[3] '-readconfig'.  And I've
> also used it for small snippets myself.  I understand, these simple
> use-cases doesn't make it right to keep it. :-)
>
> I'm not saying "don't deprecate '-readconfig'", but just noting its
> usefulness, even in its current form.  So I'm just curious if there's
> be a suggested replacement.  Even if it means: "use libvirt; or use your
> own bespoke scripts".
>
> [1] https://lists.nongnu.org/archive/html/qemu-devel/2020-05/msg03681.html
>      "proposal: deprecate -readconfig/-writeconfig"
> [2] https://lists.nongnu.org/archive/html/qemu-devel/2020-05/msg03681.html
> [3] 
> https://github.com/flyingcircusio/fc.qemu/blob/f789e57f605969a0/src/fc/qemu/agent.py#L1153