Re: [Qemu-devel] [PATCH v1 1/1] qmp: remove qmp_cpu

[Markus Armbruster <armbru@redhat.com>]

Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com> writes:

> 'qmp_cpu' was implemented in commit 755f196898 ("qapi: Convert the cpu
> command") as a functional no-op, a QMP call that does nothing and
> return success. The idea, apparently, was to provide a counterpart
> for the HMP 'hmp_cpu' command, introduced in the same commit.
>
> After 6 years of its creation, qmp_cpu remains a functional no-op
> that does nothing, having no value for any caller/user. A proposal
> was sent to implement qmp_cpu like hmp_cpu works, but it was denied
> [1]. The reason is that QMP must be as stateless as possible and a
> function that changes its state (the current CPU monitor in the case
> of qmp_cpu) goes against it. Any QMP command that needs a specific
> monitor CPU setup must provide it in its arguments, instead of relying
> in the current QMP monitor state.
>
> After discussions that happened in [2] it was decided that a command
> that does nothing since its birth, no one uses for anything and will
> not be implemented, should be deprecated and erased. Given that we will
> *not* provide any replacement for qmp_cpu and we believe that there
> is no user relying on it, there is no point in adding a deprecation
> delay for it.
>
> So, this patch nukes qmp_cpu from QEMU code, removing both its blank
> implementation in qmp.c and its doc in qapi-schema.json.
>
> [1] https://lists.gnu.org/archive/html/qemu-devel/2017-12/msg02283.html
> [2] https://lists.gnu.org/archive/html/qemu-devel/2017-12/msg03696.html
>
> Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
> CC: Markus Armbruster <armbru@redhat.com>
> CC: Eric Blake <eblake@redhat.com>
> CC: Daniel P. Berrange <berrange@redhat.com>

Lovely commit message.

I'll take this through my tree.  Thanks!