Re: [Qemu-devel] Re: [PATCH 10/15] virtio-serial: Add QMP events for failed port/device add

[Amit Shah]

On (Thu) Mar 25 2010 [15:34:06], Luiz Capitulino wrote:
> On Thu, 25 Mar 2010 09:17:17 +0530
> Amit Shah <address@hidden> wrote:
> 
> > On (Wed) Mar 24 2010 [17:34:15], Luiz Capitulino wrote:
> > > On Wed, 24 Mar 2010 20:19:28 +0530
> > > Amit Shah <address@hidden> wrote:
> > > 
> > > > When adding a port or a device to the guest fails, management software
> > > > might be interested in knowing and then cleaning up the host-side of the
> > > > port. Introduce QMP events to signal such errors.
> > > 
> > >  I'm completely unfamiliar with virtio-serial, so let me ask: how are 
> > > ports
> > > added? I'd expect the command performing this operation to fail in this 
> > > case.
> > 
> > If adding the port fails in qemu, then the command will fail. However if
> > adding the port in the guest fails, we raise this QMP event. Adding in
> > the guest could fail because of several reasons, like ENOMEM. In this
> > case, the mgmt might want to hot-unplug the port from qemu so that
> > resources are freed and also apps are notified of guest side not ready.
> 
>  Ok, what about a disconnect? Does virtio-serial have this kind of action?

In case of guest disconnect, an event is sent by the guest to the host
and the host sends it to the app. A qmp event is not triggered, one can
be, if desired.

                Amit