Re: [PATCH v4 07/22] docs/devel: document expectations for QAPI data modelling for QMP

[Eric Blake]

On Thu, Oct 28, 2021 at 04:54:42PM +0100, Daniel P. Berrangé wrote:
> Traditionally we have required that newly added QMP commands will model
> any returned data using fine grained QAPI types. This is good for
> commands that are intended to be consumed by machines, where clear data
> representation is very important. Commands that don't satisfy this have
> generally been added to HMP only.
> 

> The poster child example for this would be the 'info registers' HMP
> command which returns printf formatted data representing CPU state.
> This information varies enourmously across target architectures and

enormously

> changes relatively frequently as new CPU features are implemented.
> It is there as debugging data for human operators, and any machine
> usage would treat it as an opaque blob. It is thus reasonable to
> expose this in QMP as 'x-query-registers' returning a 'str' field.
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org