Re: [Qemu-devel] [RFC PATCH qemu] qmp: Add qom-list-properties to list QOM object properties

[Andrea Bolognani]

On Fri, 2018-01-19 at 17:15 +1100, Alexey Kardashevskiy wrote:
> > I think the existing qom-list interface does this already.
> 
> Nope, it does not. It takes path, not a type, so running with "-machine
> none" won't help.
> 
> > This won't solve the libvirt problem we were discussing, because it
> > needs an existing instance of the object.  libvirt wants to know the
> > machine properties *without* instantiating an instance.
> 
> My patch works with types, it creates an instance for a short time itself,
> this is why it does not do a thing for "pseries" as it is not a type and
> prints properties for the "pseries-2.12-machine" type.

Yeah, I took this for a spin and can confirm that it's pretty much
exactly what I was thinking about. The fact that the QMP command
instantiates objects behind the scenes is not an issue, at least
from libvirt's point of view: device-list-properties does the same
thing and we already use it quite happily; what matters is that we
can call this, along with all the other capabilities-collecting
QMP commands, in one go and on a single QEMU instance.

-- 
Andrea Bolognani / Red Hat / Virtualization