Re: [PATCH 3/8] qmp: add filtering of statistics by target vCPU

[Markus Armbruster <armbru@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> Introduce a simple filtering of statistics, that allows to retrieve
> statistics for a subset of the guest vCPUs.  This will be used for
> example by the HMP monitor, in order to retrieve the statistics
> for the currently selected CPU.
>
> Example:
> { "execute": "query-stats",
>   "arguments": {
>     "target": "vcpu",
>     "vcpus": [ "/machine/unattached/device[2]",
>                "/machine/unattached/device[4]" ] } }

What heartless people put these poor vCPUs in the orphanage?

>
> Extracted from a patch by Mark Kanda.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

[...]

> diff --git a/qapi/stats.json b/qapi/stats.json
> index bcc897258a..26ee69588f 100644
> --- a/qapi/stats.json
> +++ b/qapi/stats.json
> @@ -65,6 +65,16 @@
>  { 'enum': 'StatsTarget',
>    'data': [ 'vm', 'vcpu' ] }
>  
> +##
> +# @StatsVCPUFilter:
> +#
> +# @vcpus: list of qom paths for the desired vCPU objects.

"QOM paths", because that's how we spell it elsewhere.

> +#
> +# Since: 7.1
> +##
> +{ 'struct': 'StatsVCPUFilter',
> +  'data': { '*vcpus': [ 'str' ] } }
> +
>  ##
>  # @StatsFilter:
>  #
> @@ -73,8 +83,10 @@
>  #
>  # Since: 7.1
>  ##
> -{ 'struct': 'StatsFilter',
> -  'data': { 'target': 'StatsTarget' } }
> +{ 'union': 'StatsFilter',
> +        'base': { 'target': 'StatsTarget' },
> +  'discriminator': 'target',
> +  'data': { 'vcpu': 'StatsVCPUFilter' } }
>  
>  ##
>  # @StatsValue: