Re: [Qemu-devel] [PATCH v7 0/9] Add limited support of VMware's hyper-call rpc

[Paolo Bonzini]

On 17/06/2015 16:29, Michael S. Tsirkin wrote:
> On Wed, Jun 17, 2015 at 04:27:13PM +0200, Paolo Bonzini wrote:
>>
>>
>> On 17/06/2015 16:18, Michael S. Tsirkin wrote:
>>>>> Yes, that's what was done for parallel and pcspk as well.  There's no
>>>>> infrastructure to avoid it.
>>>>>
>>>>> Paolo
>>> How do you mean? We have multiple ways to keep devices
>>> compatible with old versions.
>>> Set a new property to skip the extra stuff.
>>
>> Not if the device didn't have a vmstate at all, unfortunately.
> 
> Skip creating the device completely for old machine types.

Which device?  The vmstate is tied to the same device that has always
been created.
 we enable this thing by default (why do we?)
>>> this seems like a big deal ...
>>
>> The PC speaker device is also enabled by default.
> 
> This is historical, isn't it?

Yes, but it has broken 2.3->2.2 migration.

Let's just stop fighting windmills.

Paolo