Re: [Qemu-devel] [PATCH v2] qmp: Add qom_path field to query-cpus command

[Markus Armbruster <armbru@redhat.com>]

Eduardo Habkost <ehabkost@redhat.com> writes:

> This will allow clients to query additional information directly using
> qom-get on the CPU objects.
>
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> Reviewed-by: Andreas Färber <afaerber@suse.de>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
> Changes v1 -> v2:
> * Renamed field from "qom-path" to "qom_path", to keep consistency
>   with existing CpuInfo fields
> * Added "(since 2.4)" to QAPI schema documentation
> * Added the new field to example on qmp-commands.hx
>
> Reference to previous discussion:
>
>   Date: Mon, 4 May 2015 15:37:40 -0300
>   From: Eduardo Habkost <ehabkost@redhat.com>
>   Message-ID: <20150504183740.GM17796@thinpad.lan.raisama.net>
>   Subject: Re: [Qemu-devel] [PATCH] cpu: Register QOM links at /machine/cpus/<index>
>
> The summary is: even if we provide predictable QOM paths for the CPU
> objects, the qom-path field will be useful to allow the QOM objects and
> query-cpu data to be matched correctly.
> ---
>  cpus.c           | 1 +
>  qapi-schema.json | 7 +++++--
>  qmp-commands.hx  | 7 +++++--
>  3 files changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/cpus.c b/cpus.c
> index 62d157a..de6469f 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -1435,6 +1435,7 @@ CpuInfoList *qmp_query_cpus(Error **errp)
>          info->value->CPU = cpu->cpu_index;
>          info->value->current = (cpu == first_cpu);
>          info->value->halted = cpu->halted;
> +        info->value->qom_path = object_get_canonical_path(OBJECT(cpu));
>          info->value->thread_id = cpu->thread_id;
>  #if defined(TARGET_I386)
>          info->value->has_pc = true;
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 9c92482..921ce70 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -679,6 +679,8 @@
>  # @halted: true if the virtual CPU is in the halt state.  Halt usually refers
>  #          to a processor specific low power mode.
>  #
> +# @qom_path: path to the CPU object in the QOM tree (since 2.4)
> +#
>  # @pc: #optional If the target is i386 or x86_64, this is the 64-bit instruction
>  #                pointer.
>  #                If the target is Sparc, this is the PC component of the
> @@ -699,8 +701,9 @@
>  #        data is sent to the client, the guest may no longer be halted.
>  ##
>  { 'struct': 'CpuInfo',
> -  'data': {'CPU': 'int', 'current': 'bool', 'halted': 'bool', '*pc': 'int',
> -           '*nip': 'int', '*npc': 'int', '*PC': 'int', 'thread_id': 'int'} }
> +  'data': {'CPU': 'int', 'current': 'bool', 'halted': 'bool', 'qom_path': 'str',

Long line.

> +           '*pc': 'int', '*nip': 'int', '*npc': 'int', '*PC': 'int',
> +           'thread_id': 'int'} }
>  
>  ##
>  # @query-cpus:
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 7506774..14e109e 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -2569,6 +2569,7 @@ Return a json-array. Each CPU is represented by a json-object, which contains:
>  - "CPU": CPU index (json-int)
>  - "current": true if this is the current CPU, false otherwise (json-bool)
>  - "halted": true if the cpu is halted, false otherwise (json-bool)
> +- "qom_path": path to the CPU object in the QOM tree (json-str)
>  - Current program counter. The key's name depends on the architecture:
>       "pc": i386/x86_64 (json-int)
>       "nip": PPC (json-int)
> @@ -2585,14 +2586,16 @@ Example:
>              "CPU":0,
>              "current":true,
>              "halted":false,
> -            "pc":3227107138
> +            "qom_path":"/machine/unattached/device[0]",
> +            "pc":3227107138,
>              "thread_id":3134
>           },
>           {
>              "CPU":1,
>              "current":false,
>              "halted":true,
> -            "pc":7108165
> +            "qom_path":"/machine/unattached/device[2]",
> +            "pc":7108165,
>              "thread_id":3135
>           }
>        ]

Applied to my qapi-next branch with the long line wrapped, thanks!