[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Making QEMU easier for management tools and applications
From: |
Markus Armbruster |
Subject: |
Re: Making QEMU easier for management tools and applications |
Date: |
Wed, 15 Jan 2020 13:15:17 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) |
Christophe de Dinechin <address@hidden> writes:
> Thanks a bunch. This clarifies a number of my misconceptions about
> how this is currently used. Most notably this one:
>
>> On 15 Jan 2020, at 10:20, Markus Armbruster <address@hidden> wrote:
>>
>>> We don’t want the QAPI to let arbitrary fields of a QOM object
>>> be modified, do we?
>>
>> We already do: QMP command qom-set. If it breaks your guest, you get to
>> keep the pieces.
>
> Ouch. I certainly did not expect that.
>
> "It is not what you don’t know that kills you, it is what you know that ain’t
> so".
Do we have a legitimate use for qom-set right now? Hmm, let's check
libvirt... aha:
* qemuMonitorJSONSetMemoryStatsPeriod() uses it to control
virtio-balloon's guest-stats-polling-interval property, in accordance
with docs/virtio-balloon-stats.txt.
* qemuMonitorJSONSetIOThread() uses it to control iothread's properties
poll-max-ns, poll-grow, poll-shrink. Their use with -object is
documented (in qemu-options.hx), their use with qom-set is not.
Oh well.
>>>> http://dreamsongs.com/RiseOfWorseIsBetter.html
>>>
>>> You know that I positively hate this ;-)
>>
>> It's been a tough lesson for me, too.
>
> Not sure I can call it a “lesson”. Much like a philosophy to fight against,
> IMO.
The tough lesson isn't philosophy, it's an observation: "I believe that
worse-is-better [...] has better survival characteristics than
the-right-thing".
>>> Well, I guess we can expand the schema. #ILoveJSON.
>>
>> Basing the QAPI language on JSON was a poor choice. Not sure that's
>> fixable at a reasonable cost.
>
> Well, at least now I have a slightly better understanding of the related costs
> and trade-offs. Thanks a lot for explaining.
You're welcome!
- Re: Making QEMU easier for management tools and applications, (continued)
Re: Making QEMU easier for management tools and applications, Christophe de Dinechin, 2020/01/07
- Re: Making QEMU easier for management tools and applications, Kevin Wolf, 2020/01/08
- Re: Making QEMU easier for management tools and applications, Christophe de Dinechin, 2020/01/08
- Re: Making QEMU easier for management tools and applications, Kevin Wolf, 2020/01/08
- Re: Making QEMU easier for management tools and applications, Markus Armbruster, 2020/01/14
- Re: Making QEMU easier for management tools and applications, Christophe de Dinechin, 2020/01/14
- Re: Making QEMU easier for management tools and applications, Markus Armbruster, 2020/01/15
- Re: Making QEMU easier for management tools and applications, Christophe de Dinechin, 2020/01/15
- Re: Making QEMU easier for management tools and applications,
Markus Armbruster <=
- Re: Making QEMU easier for management tools and applications, Daniel P . Berrangé, 2020/01/15
- Re: Making QEMU easier for management tools and applications, Markus Armbruster, 2020/01/15
- Improving QOM documentation [Was: Re: Making QEMU easier for management tools and applications], Kashyap Chamarthy, 2020/01/30
- Re: Improving QOM documentation [Was: Re: Making QEMU easier for management tools and applications], Markus Armbruster, 2020/01/31
- Re: Improving QOM documentation [Was: Re: Making QEMU easier for management tools and applications], Paolo Bonzini, 2020/01/31
- Re: Improving QOM documentation [Was: Re: Making QEMU easier for management tools and applications], Christophe de Dinechin, 2020/01/31
- Re: Improving QOM documentation [Was: Re: Making QEMU easier for management tools and applications], Paolo Bonzini, 2020/01/31
Re: Improving QOM documentation [Was: Re: Making QEMU easier for management tools and applications], Kashyap Chamarthy, 2020/01/31
Re: Improving QOM documentation [Was: Re: Making QEMU easier for management tools and applications], Peter Maydell, 2020/01/31
Re: Improving QOM documentation [Was: Re: Making QEMU easier for management tools and applications], Paolo Bonzini, 2020/01/31