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

[Gerd Hoffmann <kraxel@redhat.com>]

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?

(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