Re: [RFC PATCH 01/11] acpi: hmp/qmp: Add hmp/qmp support for system_sleep

[Markus Armbruster <armbru@redhat.com>]

You neglected to cc: QAPI schema maintainers.  I found it by chance.
Next time :)

Annie Li <annie.li@oracle.com> writes:

> Following hmp/qmp commands are implemented for pressing virtual
> sleep button,
>
> hmp: system_sleep
> qmp: { "execute": "system_sleep" }
>
> These commands put the guest into suspend or other power states
> depending on the power settings inside the guest.

How is this related to system_wakeup?

> Signed-off-by: Annie Li <annie.li@oracle.com>
> ---
>  hmp-commands.hx            | 14 ++++++++++++++
>  hw/core/machine-hmp-cmds.c |  5 +++++
>  hw/core/machine-qmp-cmds.c |  9 +++++++++
>  include/monitor/hmp.h      |  1 +
>  qapi/machine.json          | 18 ++++++++++++++++++
>  qapi/pragma.json           |  1 +
>  6 files changed, 48 insertions(+)
>
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index 765349ed14..bd01e49ec5 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -652,6 +652,20 @@ SRST
>    whether profiling is on or off.
>  ERST
>  
> +    {
> +        .name       = "system_sleep",
> +        .args_type  = "",
> +        .params     = "",
> +        .help       = "send ACPI sleep event",

Suggest "push the virtual sleep button", because it's easier to
understand, and consistent with the documentation below.

> +        .cmd = hmp_system_sleep,
> +    },
> +
> +SRST
> +``system_sleep``
> +  Push the virtual sleep button; if supported the system will enter
> +  an ACPI sleep state.
> +ERST
> +
>      {
>          .name       = "system_reset",
>          .args_type  = "",
> diff --git a/hw/core/machine-hmp-cmds.c b/hw/core/machine-hmp-cmds.c
> index a6ff6a4875..641a365e3e 100644
> --- a/hw/core/machine-hmp-cmds.c
> +++ b/hw/core/machine-hmp-cmds.c
> @@ -185,6 +185,11 @@ void hmp_system_reset(Monitor *mon, const QDict *qdict)
>      qmp_system_reset(NULL);
>  }
>  
> +void hmp_system_sleep(Monitor *mon, const QDict *qdict)
> +{
> +    qmp_system_sleep(NULL);
> +}
> +
>  void hmp_system_powerdown(Monitor *mon, const QDict *qdict)
>  {
>      qmp_system_powerdown(NULL);
> diff --git a/hw/core/machine-qmp-cmds.c b/hw/core/machine-qmp-cmds.c
> index 3860a50c3b..9f1e636c90 100644
> --- a/hw/core/machine-qmp-cmds.c
> +++ b/hw/core/machine-qmp-cmds.c
> @@ -257,6 +257,15 @@ void qmp_system_reset(Error **errp)
>      qemu_system_reset_request(SHUTDOWN_CAUSE_HOST_QMP_SYSTEM_RESET);
>  }
>  
> +void qmp_system_sleep(Error **errp)
> +{
> +    if (!qemu_wakeup_suspend_enabled()) {
> +        error_setg(errp,
> +                   "suspend from running is not supported by this guest");
> +        return;
> +    }

This can't be right: it either fails or does nothing.

I guess you're leaving the "do something" part to later patches.  That's
okay, but it needs a TODO comment here, and a prominent mention in the
commit message.

> +}
> +
>  void qmp_system_powerdown(Error **errp)
>  {
>      qemu_system_powerdown_request();
> diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
> index 13f9a2dedb..d72a3b775c 100644
> --- a/include/monitor/hmp.h
> +++ b/include/monitor/hmp.h
> @@ -45,6 +45,7 @@ void hmp_quit(Monitor *mon, const QDict *qdict);
>  void hmp_stop(Monitor *mon, const QDict *qdict);
>  void hmp_sync_profile(Monitor *mon, const QDict *qdict);
>  void hmp_system_reset(Monitor *mon, const QDict *qdict);
> +void hmp_system_sleep(Monitor *mon, const QDict *qdict);
>  void hmp_system_powerdown(Monitor *mon, const QDict *qdict);
>  void hmp_exit_preconfig(Monitor *mon, const QDict *qdict);
>  void hmp_announce_self(Monitor *mon, const QDict *qdict);
> diff --git a/qapi/machine.json b/qapi/machine.json
> index b6d634b30d..3ac69df92f 100644
> --- a/qapi/machine.json
> +++ b/qapi/machine.json
> @@ -297,6 +297,24 @@
>  ##
>  { 'command': 'system_reset' }
>  
> +##
> +# @system_sleep:
> +#
> +# Requests that a guest perform a ACPI sleep transition by pushing a virtual
> +# sleep button.

Imperative mood, please: "Request that ..."

I think "the guest" would be better.

Limit line length to 70, please.

> +#
> +# Notes: A guest may or may not respond to this command. This command
> +#        returning does not indicate that a guest has accepted the request
> +#        or that it has gone to sleep.

Please format like

    # Notes: A guest may or may not respond to this command.  This command
    #    returning does not indicate that a guest has accepted the request
    #    or that it has gone to sleep.
  
> +#
> +# Example:
> +#
> +# -> { "execute": "system_sleep" }
> +# <- { "return": {} }
> +#
> +##
> +{ 'command': 'system_sleep' }
> +
>  ##
>  # @system_powerdown:
>  #
> diff --git a/qapi/pragma.json b/qapi/pragma.json
> index 0aa4eeddd3..ef15229854 100644
> --- a/qapi/pragma.json
> +++ b/qapi/pragma.json
> @@ -23,6 +23,7 @@
>          'set_password',
>          'system_powerdown',
>          'system_reset',
> +        'system_sleep',
>          'system_wakeup' ],
>      # Commands allowed to return a non-dictionary
>      'command-returns-exceptions': [

I figure you spell system_sleep with '_' instead of '-' for consistency
with existing system_FOO commands.  That's okay, but I recommend to
point it out in the commit message.