Re: [Qemu-devel] [PATCH 1/2 v16] fsdev: add IO throttle support to fsdev devices

[Fam Zheng]

On Mon, 02/06 13:36, Eric Blake wrote:
> On 02/03/2017 05:57 AM, Pradeep Jagadeesh wrote:
> > This patchset adds the throttle support for the 9p-local driver.
> > For now this functionality can be enabled only through qemu cli options.
> > QMP interface and support to other drivers need further extensions.
> 
> This part is a bit scary - if 2.9 is released with just the cli option
> and not the QMP interface, then how does someone like libvirt introspect
> whether the feature is available for use?

Not that I want to make an unconstructive point, but just for understanding
this: if libvirt does introspect via QMP, is it technically okay to release CLI
in 2.9 and QMP in 2.10? libvirt can just ignore the possible existence of CLI
options if QMP is not there, no?

Fam