Re: [Qemu-devel] [PATCH] pc: rename machine types

[Anthony Liguori <anthony@codemonkey.ws>]

Gerd Hoffmann <kraxel@redhat.com> writes:

> On 01/08/13 14:57, Anthony Liguori wrote:
>> Gerd Hoffmann <kraxel@redhat.com> writes:
>> 
>>> Starting with release 1.4 we have a fully functional q35 machine type,
>>> i.e. "qemu -M q35" JustWorks[tm].  Update machine type names to reflect
>>> that:
>>>
>>>   * pc-1.4 becomes piix-1.4
>> 
>> PIIX is the southbridge.  A more appropriate (and google-able) name
>> would be i440fx-1.4.
>
> Fine with me.
>
>>>   * q35-next becomes q35-1.4
>> 
>> I can't help but bikeshed a little here.  I dislike that we are going
>> from something that's reasonable understandable (pc) to something
>> completely obscure (piix and q35).
>
> 'pc' is pretty generic.  I want discontinue it, except for aliasing 'pc'
> to the default machine type, for compatibility reasons.
>
> I don't care that much what the actual names are.  Using piix + q35 is
> inconsistent, so it isn't that a good choice indeed.  So what now?
>
>   (1) We could go for the host bridge and use 'i440fx' + 'q35'.
>   (2) We could go for the south bridge and use 'piix' + 'ich9'.
>   (3) Something different?

The issue I have with 'i440fx' and 'q35' is that it's basically
gibberish to a non-QEMU developer.

What about 'qemupc-legacy' and 'qemupc'?  'pc' can still be an alias for
'qemupc-legacy'.

I very much like the legacy distinction as it steers users toward q35
which I think is what we want.

Regards,

Anthony Liguori

>
> (1) has the advantage that we keep the established name 'q35' for the
>     new machine type.
> (2) has the advantage that it matches the naming convention of
>     several devices in the tree (piix/ich9 prefix).
>
>> I would be in favor of the i440fx machine being called "legacy-pc" and
>> q35 gaining the title of "pc".
>
> No way.  Assigning 'pc' to q35 is asking for serious trouble.  That way
> 'qemu -M pc' silently switches the chipset underneath the guest when
> upgrading from 1.3 to 1.4.
>
> cheers,
>   Gerd