Re: [Qemu-devel] [PATCH 3/6] virtio-console: Add a virtio-console bus, support for multiple ports

[Gerd Hoffmann <kraxel@redhat.com>]

On 10/07/09 11:25, Amit Shah wrote:
>>    -device virtio-serial-bus,chardev=<name>
>>
>> automatically creates a virtioconsole with port=0 and chardev=<name>  on
>> the newly created bus.
>
> Hm, this looks weird. Because on one hand we're talking about decoupling
> the char driver from the core (virtio-serial-bus) and here we're
> actually attaching a char driver to the bus.

We don't actually attach the chardev to the bus though.  It is just 
passed through to the auto-created console port #0.

But it looks a bit weird indeed.  I'm open to better suggestions to 
address the "port #0 must be console for backward compatibility reasons" 
issue.

>> Keeping -virtioconsole for backward compatibility is easy, it would
>> basically create a chardev with a virtio<nr>  label as it does today,
>> then create virtio-serial-bus with chardev=virtio<nr>.
>
> I prefer to remove the -virtioconsole argument because we won't be able
> to specify the bus that's to be attached to.

Oh, I thought it would create a new virtio-serial-bus (plus auto-created 
port0 console) unconditionally.  Just do enougth to keep existing users 
of the switch working.

If you want new features (i.e. two consoles ports attached to one 
virtio-serial-bus device) you must use the new syntax.

cheers,
   Gerd