Re: KVM call for agenda for 2020-10-06

[Paolo Bonzini <pbonzini@redhat.com>]

On 06/10/20 20:21, Stefan Hajnoczi wrote:
>     * Does command-line order matter?
>         * Two options: allow any order OR left-to-right ordering
>         * Andrea Bolognani: Most users expect left-to-right ordering,
> why allow any order?
>         * Eduardo Habkost: Can we enforce left-to-right ordering or do
> we need to follow the deprecation process?
>         * Daniel Berrange: Solve compability by introducing new
> binaries without the burden of backwards compability

I think "new binaries" shouldn't even have a command line; all
configuration should happen through QMP commands.  Those are naturally
time-ordered, which is equivalent to left-to-right, and therefore the
question is sidestepped.  Perhaps even having a command line in
qemu-storage-daemon was a mistake.

For "old binaries" we are not adding too many options, so apart from the
nasty distinction between early and late objects we're at least not
making it worse.

The big question to me is whether the configuration should be
QAPI-based, that is based on QAPI structs, or QMP-based.  If the latter,
"object-add" (and to a lesser extent "device-add") are fine mechanisms
for configuration.  There is still need for better QOM introspection,
but it would be much simpler than doing QOM object creation via QAPI
struct, if at all possible.						

Paolo