Kevin Wolf <kw...@redhat.com> writes:
> Often, QMP command handlers are not only called to handle QMP commands,
> but also from a corresponding HMP command handler. In order to give them
> a consistent environment, optionally run HMP command handlers in a
> coroutine, too.
>
> The implementation is a lot simpler than in QMP because for HMP, we
> still block the VM while the coroutine is running.
>
> Signed-off-by: Kevin Wolf <kw...@redhat.com>
> ---
> monitor/monitor-internal.h | 1 +
> monitor/hmp.c | 38 ++++++++++++++++++++++++++++++++------
> 2 files changed, 33 insertions(+), 6 deletions(-)
>
> diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h
> index b55d6df07f..ad2e64be13 100644
> --- a/monitor/monitor-internal.h
> +++ b/monitor/monitor-internal.h
> @@ -74,6 +74,7 @@ typedef struct HMPCommand {
> const char *help;
> const char *flags; /* p=preconfig */
> void (*cmd)(Monitor *mon, const QDict *qdict);
> + bool coroutine;
> /*
> * @sub_table is a list of 2nd level of commands. If it does not exist,
> * cmd should be used. If it exists, sub_table[?].cmd should be
> diff --git a/monitor/hmp.c b/monitor/hmp.c
> index 3e73a4c3ce..ab0e3e279f 100644
> --- a/monitor/hmp.c
> +++ b/monitor/hmp.c
> @@ -1056,12 +1056,25 @@ fail:
> return NULL;
> }
>
> +typedef struct HandleHmpCommandCo {
> + Monitor *mon;
> + const HMPCommand *cmd;
> + QDict *qdict;
> + bool done;
> +} HandleHmpCommandCo;
> +
> +static void handle_hmp_command_co(void *opaque)
> +{
> + HandleHmpCommandCo *data = opaque;
> + data->cmd->cmd(data->mon, data->qdict);
> + data->done = true;
> +}
> +
> void handle_hmp_command(MonitorHMP *mon, const char *cmdline)
> {
> QDict *qdict;
> const HMPCommand *cmd;
> const char *cmd_start = cmdline;
> - Monitor *old_mon;
>
> trace_handle_hmp_command(mon, cmdline);
>
> @@ -1080,11 +1093,24 @@ void handle_hmp_command(MonitorHMP *mon, const char
> *cmdline)
> return;
> }
>
> - /* old_mon is non-NULL when called from qmp_human_monitor_command() */
> - old_mon = monitor_cur();
> - monitor_set_cur(qemu_coroutine_self(), &mon->common);
> - cmd->cmd(&mon->common, qdict);
> - monitor_set_cur(qemu_coroutine_self(), old_mon);
> + if (!cmd->coroutine) {
> + /* old_mon is non-NULL when called from qmp_human_monitor_command()
> */
> + Monitor *old_mon = monitor_cur();
> + monitor_set_cur(qemu_coroutine_self(), &mon->common);
> + cmd->cmd(&mon->common, qdict);
> + monitor_set_cur(qemu_coroutine_self(), old_mon);
> + } else {
> + HandleHmpCommandCo data = {
> + .mon = &mon->common,
> + .cmd = cmd,
> + .qdict = qdict,
> + .done = false,
> + };
> + Coroutine *co = qemu_coroutine_create(handle_hmp_command_co, &data);
> + monitor_set_cur(co, &mon->common);
Where is the matching monitor_set_cur(co, NULL)?
> + aio_co_enter(qemu_get_aio_context(), co);
> + AIO_WAIT_WHILE(qemu_get_aio_context(), !data.done);
> + }
>
> qobject_unref(qdict);
> }
