Re: [PATCH 01/15] remove preconfig state

[Igor Mammedov]

On Mon, 7 Dec 2020 15:11:34 +0100
Paolo Bonzini <pbonzini@redhat.com> wrote:

> Il lun 7 dic 2020, 14:57 Igor Mammedov <imammedo@redhat.com> ha scritto:
> 
> > On Wed,  2 Dec 2020 03:18:40 -0500
> > Paolo Bonzini <pbonzini@redhat.com> wrote:
> >  
> > > The preconfig state is only used if -incoming is not specified, which
> > > makes the RunState state machine more tricky than it need be.  However
> > > there is already an equivalent condition which works even with -incoming,
> > > namely qdev_hotplug.  Use it instead of a separate runstate.
> > >
> > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> > > ---
> > >  hw/core/machine-qmp-cmds.c    |  5 ++---
> > >  include/qapi/qmp/dispatch.h   |  1 +
> > >  monitor/hmp.c                 |  7 ++++---
> > >  monitor/qmp-cmds.c            |  5 ++---
> > >  qapi/qmp-dispatch.c           |  5 +----
> > >  qapi/run-state.json           |  5 +----
> > >  softmmu/qdev-monitor.c        | 12 ++++++++++++
> > >  softmmu/vl.c                  | 13 ++-----------
> > >  stubs/meson.build             |  1 +
> > >  stubs/qmp-command-available.c |  7 +++++++
> > >  tests/qtest/qmp-test.c        |  2 +-
> > >  11 files changed, 34 insertions(+), 29 deletions(-)
> > >  create mode 100644 stubs/qmp-command-available.c
> > >
> > > diff --git a/hw/core/machine-qmp-cmds.c b/hw/core/machine-qmp-cmds.c
> > > index 5362c80a18..cb9387c5f5 100644
> > > --- a/hw/core/machine-qmp-cmds.c
> > > +++ b/hw/core/machine-qmp-cmds.c
> > > @@ -286,9 +286,8 @@ HotpluggableCPUList  
> > *qmp_query_hotpluggable_cpus(Error **errp)  
> > >
> > >  void qmp_set_numa_node(NumaOptions *cmd, Error **errp)
> > >  {
> > > -    if (!runstate_check(RUN_STATE_PRECONFIG)) {
> > > -        error_setg(errp, "The command is permitted only in '%s' state",
> > > -                   RunState_str(RUN_STATE_PRECONFIG));
> > > +    if (qdev_hotplug) {  
> > it's too late for qmp_set_numa_node(), but given it's temporary
> > and patch 8/15 changes it to correct state it should be fine.
> > so
> >
> >   Reviewed-by: Igor Mammedov <imammedo@redhat.com>
> >  
> 
> It's too late according to the fine grained distinction of phases that will
> be introduced later. For the two phases that are possible with current QEMU
> (before or after preconfig) it should be indistinguishable, right?
yep, it doesn't break anything and 8/15 makes sure that command ends up at
correct phase.

> 
> Paolo
> 
> 
> >  
> > > +         error_setg(errp, "The command is permitted only before the  
> > machine has been created");  
> > >           return;
> > >      }
> > >
> > > diff --git a/include/qapi/qmp/dispatch.h b/include/qapi/qmp/dispatch.h
> > > index af8d96c570..1486cac3ef 100644
> > > --- a/include/qapi/qmp/dispatch.h
> > > +++ b/include/qapi/qmp/dispatch.h
> > > @@ -48,6 +48,7 @@ void qmp_disable_command(QmpCommandList *cmds, const  
> > char *name);  
> > >  void qmp_enable_command(QmpCommandList *cmds, const char *name);
> > >
> > >  bool qmp_command_is_enabled(const QmpCommand *cmd);
> > > +bool qmp_command_available(const QmpCommand *cmd, Error **errp);
> > >  const char *qmp_command_name(const QmpCommand *cmd);
> > >  bool qmp_has_success_response(const QmpCommand *cmd);
> > >  QDict *qmp_error_response(Error *err);
> > > diff --git a/monitor/hmp.c b/monitor/hmp.c
> > > index d40f4f4391..f2fe192d69 100644
> > > --- a/monitor/hmp.c
> > > +++ b/monitor/hmp.c
> > > @@ -24,6 +24,7 @@
> > >
> > >  #include "qemu/osdep.h"
> > >  #include <dirent.h>
> > > +#include "hw/qdev-core.h"
> > >  #include "monitor-internal.h"
> > >  #include "qapi/error.h"
> > >  #include "qapi/qmp/qdict.h"
> > > @@ -215,7 +216,7 @@ static bool cmd_can_preconfig(const HMPCommand *cmd)
> > >
> > >  static bool cmd_available(const HMPCommand *cmd)
> > >  {
> > > -    return !runstate_check(RUN_STATE_PRECONFIG) ||  
> > cmd_can_preconfig(cmd);  
> > > +    return qdev_hotplug || cmd_can_preconfig(cmd);
> > >  }
> > >
> > >  static void help_cmd_dump_one(Monitor *mon,
> > > @@ -658,8 +659,8 @@ static const HMPCommand  
> > *monitor_parse_command(MonitorHMP *hmp_mon,  
> > >          return NULL;
> > >      }
> > >      if (!cmd_available(cmd)) {
> > > -        monitor_printf(mon, "Command '%.*s' not available with  
> > -preconfig "  
> > > -                            "until after exit_preconfig.\n",
> > > +        monitor_printf(mon, "Command '%.*s' not available "
> > > +                            "until machine initialization has  
> > completed.\n",  
> > >                         (int)(p - cmdp_start), cmdp_start);
> > >          return NULL;
> > >      }
> > > diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c
> > > index 6299c0c8c7..501a3024c7 100644
> > > --- a/monitor/qmp-cmds.c
> > > +++ b/monitor/qmp-cmds.c
> > > @@ -104,9 +104,8 @@ void qmp_system_powerdown(Error **errp)
> > >
> > >  void qmp_x_exit_preconfig(Error **errp)
> > >  {
> > > -    if (!runstate_check(RUN_STATE_PRECONFIG)) {
> > > -        error_setg(errp, "The command is permitted only in '%s' state",
> > > -                   RunState_str(RUN_STATE_PRECONFIG));
> > > +    if (qdev_hotplug) {
> > > +        error_setg(errp, "The command is permitted only before machine  
> > initialization");  
> > >          return;
> > >      }
> > >      qemu_exit_preconfig_request();
> > > diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c
> > > index 9a2d7dd29a..0a2b20a4e4 100644
> > > --- a/qapi/qmp-dispatch.c
> > > +++ b/qapi/qmp-dispatch.c
> > > @@ -167,10 +167,7 @@ QDict *qmp_dispatch(const QmpCommandList *cmds,  
> > QObject *request,  
> > >          goto out;
> > >      }
> > >
> > > -    if (runstate_check(RUN_STATE_PRECONFIG) &&
> > > -        !(cmd->options & QCO_ALLOW_PRECONFIG)) {
> > > -        error_setg(&err, "The command '%s' isn't permitted in '%s'  
> > state",  
> > > -                   cmd->name, RunState_str(RUN_STATE_PRECONFIG));
> > > +    if (!qmp_command_available(cmd, &err)) {
> > >          goto out;
> > >      }
> > >
> > > diff --git a/qapi/run-state.json b/qapi/run-state.json
> > > index 964c8ef391..38194b0e44 100644
> > > --- a/qapi/run-state.json
> > > +++ b/qapi/run-state.json
> > > @@ -50,15 +50,12 @@
> > >  # @colo: guest is paused to save/restore VM state under colo checkpoint,
> > >  #        VM can not get into this state unless colo capability is  
> > enabled  
> > >  #        for migration. (since 2.8)
> > > -# @preconfig: QEMU is paused before board specific init callback is  
> > executed.  
> > > -#             The state is reachable only if the --preconfig CLI option  
> > is used.  
> > > -#             (Since 3.0)
> > >  ##
> > >  { 'enum': 'RunState',
> > >    'data': [ 'debug', 'inmigrate', 'internal-error', 'io-error',  
> > 'paused',  
> > >              'postmigrate', 'prelaunch', 'finish-migrate', 'restore-vm',
> > >              'running', 'save-vm', 'shutdown', 'suspended', 'watchdog',
> > > -            'guest-panicked', 'colo', 'preconfig' ] }
> > > +            'guest-panicked', 'colo' ] }
> > >
> > >  ##
> > >  # @ShutdownCause:
> > > diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
> > > index d060e765da..e967d13bd0 100644
> > > --- a/softmmu/qdev-monitor.c
> > > +++ b/softmmu/qdev-monitor.c
> > > @@ -25,6 +25,7 @@
> > >  #include "sysemu/arch_init.h"
> > >  #include "qapi/error.h"
> > >  #include "qapi/qapi-commands-qdev.h"
> > > +#include "qapi/qmp/dispatch.h"
> > >  #include "qapi/qmp/qdict.h"
> > >  #include "qapi/qmp/qerror.h"
> > >  #include "qemu/config-file.h"
> > > @@ -997,3 +998,14 @@ int qemu_global_option(const char *str)
> > >
> > >      return 0;
> > >  }
> > > +
> > > +bool qmp_command_available(const QmpCommand *cmd, Error **errp)
> > > +{
> > > +    if (!qdev_hotplug &&
> > > +        !(cmd->options & QCO_ALLOW_PRECONFIG)) {
> > > +        error_setg(errp, "The command '%s' is permitted only after  
> > machine initialization has completed",  
> > > +                   cmd->name);
> > > +        return false;
> > > +    }
> > > +    return true;
> > > +}
> > > diff --git a/softmmu/vl.c b/softmmu/vl.c
> > > index 7146fbe219..ab2210bc79 100644
> > > --- a/softmmu/vl.c
> > > +++ b/softmmu/vl.c
> > > @@ -557,7 +557,7 @@ static int default_driver_check(void *opaque,  
> > QemuOpts *opts, Error **errp)  
> > >  /***********************************************************/
> > >  /* QEMU state */
> > >
> > > -static RunState current_run_state = RUN_STATE_PRECONFIG;
> > > +static RunState current_run_state = RUN_STATE_PRELAUNCH;
> > >
> > >  /* We use RUN_STATE__MAX but any invalid value will do */
> > >  static RunState vmstop_requested = RUN_STATE__MAX;
> > > @@ -569,13 +569,7 @@ typedef struct {
> > >  } RunStateTransition;
> > >
> > >  static const RunStateTransition runstate_transitions_def[] = {
> > > -    /*     from      ->     to      */
> > > -    { RUN_STATE_PRECONFIG, RUN_STATE_PRELAUNCH },
> > > -      /* Early switch to inmigrate state to allow  -incoming CLI option  
> > work  
> > > -       * as it used to. TODO: delay actual switching to inmigrate state  
> > to  
> > > -       * the point after machine is built and remove this hack.
> > > -       */
> > > -    { RUN_STATE_PRECONFIG, RUN_STATE_INMIGRATE },
> > > +    { RUN_STATE_PRELAUNCH, RUN_STATE_INMIGRATE },
> > >
> > >      { RUN_STATE_DEBUG, RUN_STATE_RUNNING },
> > >      { RUN_STATE_DEBUG, RUN_STATE_FINISH_MIGRATE },
> > > @@ -1471,9 +1465,6 @@ static bool main_loop_should_exit(void)
> > >      ShutdownCause request;
> > >
> > >      if (preconfig_exit_requested) {
> > > -        if (runstate_check(RUN_STATE_PRECONFIG)) {
> > > -            runstate_set(RUN_STATE_PRELAUNCH);
> > > -        }
> > >          preconfig_exit_requested = false;
> > >          return true;
> > >      }
> > > diff --git a/stubs/meson.build b/stubs/meson.build
> > > index 82b7ba60ab..cc56c83063 100644
> > > --- a/stubs/meson.build
> > > +++ b/stubs/meson.build
> > > @@ -29,6 +29,7 @@ stub_ss.add(files('pci-bus.c'))
> > >  stub_ss.add(files('pci-host-piix.c'))
> > >  stub_ss.add(files('qemu-timer-notify-cb.c'))
> > >  stub_ss.add(files('qmp_memory_device.c'))
> > > +stub_ss.add(files('qmp-command-available.c'))
> > >  stub_ss.add(files('qtest.c'))
> > >  stub_ss.add(files('ram-block.c'))
> > >  stub_ss.add(files('ramfb.c'))
> > > diff --git a/stubs/qmp-command-available.c  
> > b/stubs/qmp-command-available.c  
> > > new file mode 100644
> > > index 0000000000..46540af7bf
> > > --- /dev/null
> > > +++ b/stubs/qmp-command-available.c
> > > @@ -0,0 +1,7 @@
> > > +#include "qemu/osdep.h"
> > > +#include "qapi/qmp/dispatch.h"
> > > +
> > > +bool qmp_command_available(const QmpCommand *cmd, Error **errp)
> > > +{
> > > +    return true;
> > > +}
> > > diff --git a/tests/qtest/qmp-test.c b/tests/qtest/qmp-test.c
> > > index eb1cd8abb8..11614bf63f 100644
> > > --- a/tests/qtest/qmp-test.c
> > > +++ b/tests/qtest/qmp-test.c
> > > @@ -295,7 +295,7 @@ static void test_qmp_preconfig(void)
> > >      rsp = qtest_qmp(qs, "{ 'execute': 'query-status' }");
> > >      ret = qdict_get_qdict(rsp, "return");
> > >      g_assert(ret);
> > > -    g_assert_cmpstr(qdict_get_try_str(ret, "status"), ==, "preconfig");
> > > +    g_assert_cmpstr(qdict_get_try_str(ret, "status"), ==, "prelaunch");
> > >      qobject_unref(rsp);
> > >
> > >      /* exit preconfig state */  
> >
> >