Re: [Qemu-devel] What's the next QEMU version after 2.9 ? (or: when is a good point in time to get rid of old interfaces)

[Thomas Huth <thuth@redhat.com>]

On 27.03.2017 21:04, John Snow wrote:
> 
> 
> On 03/27/2017 04:06 AM, Thomas Huth wrote:
>> On 24.03.2017 23:10, John Snow wrote:
>>>
>>>
>>> On 03/08/2017 03:26 AM, Thomas Huth wrote:
>>>>
>>>>  Hi everybody,
>>>>
>>>> what will be the next version of QEMU after 2.9? Will we go for a 2.10
>>>> (as I've seen it mentioned a couple of times on the mailing list
>>>> already), or do we dare to switch to 3.0 instead?
>>>>
>>>> I personally dislike two-digit minor version numbers like 2.10 since the
>>>> non-experienced users sometimes mix it up with 2.1 ... and there have
>>>> been a couple of new cool features in the past releases that would
>>>> justify a 3.0 now, too, I think.
>>>>
>>>> But anyway, the more important thing that keeps me concerned is: Someone
>>>>  once told me that we should get rid of old parameters and interfaces
>>>> (like HMP commands) primarily only when we're changing to a new major
>>>> version number. As you all know, QEMU has a lot of legacy options, which
>>>> are likely rather confusing than helpful for the new users nowadays,
>>>> e.g. things like the "-net channel" option (which is fortunately even
>>>> hardly documented), but maybe also even the whole vlan/hub concept in
>>>> the net code, or legacy parameters like "-usbdevice". If we switch to
>>>> version 3.0, could we agree to remove at least some of them?
>>>>
>>>>  Thomas
>>>>
>>>
>>> As others have stated, we need a few releases to deprecate things first.
>>>
>>> Maybe we should develop a serious plan to develop some of our legacy
>>> interfaces first.
>>>
>>> Maybe 2.10 can introduce a list of things we want to deprecate,
>>> 2.11 can be the transition release,
>>> and then 3.0 can cut the cord and free of us our terrible burden?
>>>
>>> I have a list of things I want to axe...
>>
>> I've started a Wiki page with such a list here:
>>
>> http://wiki.qemu-project.org/Features/LegacyRemoval
>>
>> Feel free to amend!
>>
> 
> Absolutely!
> 
> Should we make an effort to print warnings for any of these items in the
> list for 2.10 that they may disappear for 3.0?

Yes, I think there was something like a consensus earlier in this thread
that we should warn for at least two releases before removing a legacy
interface, so we should make sure that we add a warning for the listed
items in 2.10.

> It'd be nice to turn this wiki list into something that we're actually
> definitely going to do.

I definitely plan to add some warnings once the hard freeze is over and
the development tree opens again. If you want to help with the patches,
you're very welcome!

 Thomas