Re: [Qemu-devel] [PATCH v2 1/2] Deprecate QMP `cpu-add`

[Thomas Huth]

On 2018-09-25 18:02, Kashyap Chamarthy wrote:
> The intended functionality of QMP `cpu-add` is replaced with
> `device_add` (and `query-hotpluggable-cpus`).  So let's deprecate
> `cpu-add`.
> 
> A complete example of vCPU hotplug with the recommended way (using
> `device_add`) is provided as part of a seperate docs patch.
> 
> Suggested-by: Eduardo Habkost <address@hidden
> Signed-off-by: Kashyap Chamarthy <address@hidden>
> ---
> ---
>  qapi/misc.json       | 8 +++++++-
>  qemu-deprecated.texi | 5 +++++
>  2 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/qapi/misc.json b/qapi/misc.json
> index d450cfef21..6479b8f8a6 100644
> --- a/qapi/misc.json
> +++ b/qapi/misc.json
> @@ -1104,7 +1104,11 @@
>  ##
>  # @cpu-add:
>  #
> -# Adds CPU with specified ID
> +# Adds CPU with specified ID.
> +#
> +# Notes: This command is deprecated.  The `device_add` command should be

s/Notes/Note/ ?

> +#        used instead.  See the `query-hotpluggable-cpus` command for
> +#        details.
>  #
>  # @id: ID of CPU to be created, valid values [0..max_cpus)
>  #
> @@ -3213,6 +3217,8 @@
>  ##
>  # @query-hotpluggable-cpus:
>  #
> +# TODO: Better documentation; currently there is none.
> +#
>  # Returns: a list of HotpluggableCPU objects.
>  #
>  # Since: 2.7
> diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi
> index 1b9c007f12..c86924ad9a 100644
> --- a/qemu-deprecated.texi
> +++ b/qemu-deprecated.texi
> @@ -155,6 +155,11 @@ The ``query-cpus'' command is replaced by the 
> ``query-cpus-fast'' command.
>  The ``arch'' output member of the ``query-cpus-fast'' command is
>  replaced by the ``target'' output member.
>  
> address@hidden cpu-add (since 3.1)
> +
> +Use ``device_add'' for hotplugging vCPUs instead of ``cpu-add''.  See
> +documentation of ``query-hotpluggable-cpus'' for additional details.
> +
>  @section System emulator devices
>  
>  @subsection ivshmem (since 2.6.0)
> 

Do you plan to keep the "cpu-add" HMP command? hmp_cpu_add() currently
is only a wrapper for qmp_cpu_add(), so if you plan to get rid of the
QMP command, it might make sense to deprecate the HMP command in the
same breath, too.

 Thomas