[libvirt] [PATCH 1/2] conf: add debugcon-isa chardev guest interface

[Andrea Bolognani]

On Mon, 2019-01-28 at 10:36 +0000, Daniel P. Berrangé wrote:
> On Mon, Jan 28, 2019 at 11:24:38AM +0100, Andrea Bolognani wrote:
> > Should this be a <channel> at all?
> > 
> > We generally use <serial> for native emulated devices such as
> > isa-serial, which isa-debugcon seems very closely related to...
> 
> <channel> is aiming to expose application specific guest data channels.
> 
> <serial> is aiming to expose general purpose guest data channels.
> 
> To me isa-debugcon is an application specific data channels, so
> <channel> feels a better fit.

Maybe I have misunderstood what isa-debugcon is, but it looks more
of a general purpose channel in the vein of isa-serial rather than
something application specific like the qemu-guest-agent or SPICE
channels for example.

> > Perhaps the best way to hook this up would be
> > 
> >   <serial type='pty'>
> >     <target type='isa-serial'>
> 
> IMHO using 'isa-serial' would be misleading for applications which
> know about <serial> ports today and may well cause unexpected side
> effects, especially wrt to the <console> mapping of the first <serial>
> port.

Good point about the <console>/<serial> mapping, which we should
make sure is handled correctly.

-- 
Andrea Bolognani / Red Hat / Virtualization