Re: [Qemu-devel] [PATCH v2] New QMP command query-cpu-max and HMP command cpu_max

[Luiz Capitulino <lcapitulino@redhat.com>]

On Mon, 25 Mar 2013 16:58:50 +0100
Michal Novotny <minovotn@redhat.com> wrote:

> These commands return the maximum number of CPUs supported by the

/These commands/This command

> currently running emulator instance, as defined in its QEMUMachine
> struct.
> 
> Signed-off-by: Michal Novotny <minovotn@redhat.com>
> ---
>  hmp-commands.hx  | 14 ++++++++++++++
>  hmp.c            | 15 +++++++++++++++
>  hmp.h            |  1 +
>  qapi-schema.json | 11 +++++++++++
>  qmp-commands.hx  | 22 ++++++++++++++++++++++
>  vl.c             |  5 +++++
>  6 files changed, 68 insertions(+)
> 
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index df44906..c976459 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -690,6 +690,20 @@ Set the default CPU.
>  ETEXI
>  
>      {
> +        .name       = "cpu_max",
> +        .args_type  = "",
> +        .params     = "",
> +        .help       = "Get maximum number of VCPUs supported by machine",
> +        .mhandler.cmd = hmp_query_cpu_max,
> +    },
> +
> +STEXI
> +@item cpu_max
> +@findex cpu_max
> +Returns the number of CPUs supported by the machine being emulated.
> +ETEXI
> +
> +    {
>          .name       = "mouse_move",
>          .args_type  = "dx_str:s,dy_str:s,dz_str:s?",
>          .params     = "dx dy [dz]",
> diff --git a/hmp.c b/hmp.c
> index b0a861c..6d5674f 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -748,6 +748,21 @@ void hmp_ringbuf_read(Monitor *mon, const QDict *qdict)
>      g_free(data);
>  }
>  
> +void hmp_query_cpu_max(Monitor *mon, const QDict *qdict)
> +{
> +    int cpu_max;
> +    Error *errp = NULL;
> +
> +    cpu_max = qmp_query_cpu_max(&errp);
> +    if (errp) {
> +        monitor_printf(mon, "%s\n", error_get_pretty(errp));
> +        error_free(errp);
> +        return;
> +    }

Sorry for not noticing this before, but you can pass NULL to
qmp_query_cpu_max(), as it never fails.

> +
> +    monitor_printf(mon, "Maximum number of CPUs is %d\n", cpu_max);
> +}
> +
>  static void hmp_cont_cb(void *opaque, int err)
>  {
>      if (!err) {
> diff --git a/hmp.h b/hmp.h
> index 95fe76e..80e8b41 100644
> --- a/hmp.h
> +++ b/hmp.h
> @@ -42,6 +42,7 @@ void hmp_stop(Monitor *mon, const QDict *qdict);
>  void hmp_system_reset(Monitor *mon, const QDict *qdict);
>  void hmp_system_powerdown(Monitor *mon, const QDict *qdict);
>  void hmp_cpu(Monitor *mon, const QDict *qdict);
> +void hmp_query_cpu_max(Monitor *mon, const QDict *qdict);
>  void hmp_memsave(Monitor *mon, const QDict *qdict);
>  void hmp_pmemsave(Monitor *mon, const QDict *qdict);
>  void hmp_ringbuf_write(Monitor *mon, const QDict *qdict);
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 088f4e1..a8187fd 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -1832,6 +1832,17 @@
>  { 'command': 'query-migrate-cache-size', 'returns': 'int' }
>  
>  ##
> +## @query-cpu-max
> +##
> +## query maximum number of CPUs supported by machine
> +##
> +## Returns: number of CPUs
> +##
> +## Since: 1.5
> +###
> +{ 'command': 'query-cpu-max', 'returns': 'int' }
> +
> +##
>  # @ObjectPropertyInfo:
>  #
>  # @name: the name of the property
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index b370060..9c6b802 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -385,6 +385,28 @@ Note: CPUs' indexes are obtained with the 'query-cpus' command.
>  EQMP
>  
>      {
> +        .name       = "query-cpu-max",
> +        .args_type  = "",
> +        .mhandler.cmd_new = qmp_marshal_input_query_cpu_max,
> +    },
> +
> +SQMP
> +query-cpu-max
> +-------------
> +
> +Get the maximum CPUs supported by the machine being currently
> +emulated.
> +
> +Returns json-int.
> +
> +Example:
> +
> +-> { "execute": "query-cpu-max" }
> +<- { "return": 255 }
> +
> +EQMP
> +
> +    {
>          .name       = "memsave",
>          .args_type  = "val:l,size:i,filename:s,cpu:i?",
>          .mhandler.cmd_new = qmp_marshal_input_memsave,
> diff --git a/vl.c b/vl.c
> index aeed7f4..7643f16 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -662,6 +662,11 @@ StatusInfo *qmp_query_status(Error **errp)
>      return info;
>  }
>  
> +int64_t qmp_query_cpu_max(Error **errp)
> +{
> +    return current_machine->max_cpus;
> +}
> +
>  /***********************************************************/
>  /* real time host monotonic timer */
>