[21/36] vl: initialize displays before preconfig loop

Displays should be available before the monitor starts, so that
it is possible to use the graphical console to interact with
the monitor itself.

This patch is quite ugly, but all this is temporary.  The double
call to qemu_init_displays will go away as soon we can unify machine
initialization between the preconfig and "normal" flows, and so will
the preconfig_exit_requested variable (that is only preconfig_requested
remains).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 softmmu/vl.c | 57 +++++++++++++++++++++++++++++++++-------------------
 1 file changed, 36 insertions(+), 21 deletions(-)

On Mon, 23 Nov 2020 09:14:20 -0500
Paolo Bonzini <pbonzini@redhat.com> wrote:

> Displays should be available before the monitor starts, so that
> it is possible to use the graphical console to interact with
> the monitor itself.
> 
> This patch is quite ugly, but all this is temporary.  The double
> call to qemu_init_displays will go away as soon we can unify machine
> initialization between the preconfig and "normal" flows, and so will
> the preconfig_exit_requested variable (that is only preconfig_requested
> remains).
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  softmmu/vl.c | 57 +++++++++++++++++++++++++++++++++-------------------
>  1 file changed, 36 insertions(+), 21 deletions(-)
> 
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index 6c8a103178..073d7412ad 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -137,6 +137,7 @@ static ram_addr_t maxram_size;
>  static uint64_t ram_slots;
>  static int display_remote;
>  static int snapshot;
> +static bool preconfig_requested;
>  static QemuPluginList plugin_list = QTAILQ_HEAD_INITIALIZER(plugin_list);
>  static BlockdevOptionsQueue bdo_queue = QSIMPLEQ_HEAD_INITIALIZER(bdo_queue);
>  static bool nographic = false;
> @@ -3211,12 +3212,12 @@ static void qemu_validate_options(void)
>            }
>      }
>  
> -    if (loadvm && !preconfig_exit_requested) {
> +    if (loadvm && preconfig_requested) {
>          error_report("'preconfig' and 'loadvm' options are "
>                       "mutually exclusive");
>          exit(EXIT_FAILURE);
>      }
> -    if (incoming && !preconfig_exit_requested) {
> +    if (incoming && preconfig_requested) {
>          error_report("'preconfig' and 'incoming' options are "
>                       "mutually exclusive");
>          exit(EXIT_FAILURE);
> @@ -3380,6 +3381,28 @@ static void qemu_init_subsystems(void)
>      socket_init();
>  }
>  
> +static void qemu_init_displays(void)
> +{
> +    DisplayState *ds;
> +
> +    /* init local displays */
> +    ds = init_displaystate();
> +    qemu_display_init(ds, &dpy);
> +
> +    /* must be after terminal init, SDL library changes signal handlers */
> +    os_setup_signal_handling();
> +
> +    /* init remote displays */
> +#ifdef CONFIG_VNC
> +    qemu_opts_foreach(qemu_find_opts("vnc"),
> +                      vnc_init_func, NULL, &error_fatal);
> +#endif
> +
> +    if (using_spice) {
> +        qemu_spice.display_init();
> +    }
> +}
> +
>  /*
>   * Called after leaving preconfig state.  From here on runstate is
>   * RUN_STATE_PRELAUNCH or RUN_STATE_INMIGRATE.
> @@ -3443,8 +3466,6 @@ static void qemu_create_cli_devices(void)
>  
>  static void qemu_machine_creation_done(void)
>  {
> -    DisplayState *ds;
> -
>      cpu_synchronize_all_post_init();
>  
>      /* Did we create any drives that we failed to create a device for? */
> @@ -3467,23 +3488,6 @@ static void qemu_machine_creation_done(void)
>          qemu_register_reset(restore_boot_order, g_strdup(boot_order));
>      }
>  
> -    /* init local displays */
> -    ds = init_displaystate();
> -    qemu_display_init(ds, &dpy);
> -
> -    /* must be after terminal init, SDL library changes signal handlers */
> -    os_setup_signal_handling();
> -
> -    /* init remote displays */
> -#ifdef CONFIG_VNC
> -    qemu_opts_foreach(qemu_find_opts("vnc"),
> -                      vnc_init_func, NULL, &error_fatal);
> -#endif
> -
> -    if (using_spice) {
> -        qemu_spice.display_init();
> -    }
> -
>      if (foreach_device_config(DEV_GDB, gdbserver_start) < 0) {
>          exit(1);
>      }
> @@ -4083,6 +4087,7 @@ void qemu_init(int argc, char **argv, char **envp)
>                  break;
>              case QEMU_OPTION_preconfig:
>                  preconfig_exit_requested = false;
> +                preconfig_requested = true;
>                  break;
>              case QEMU_OPTION_enable_kvm:
>                  olist = qemu_find_opts("machine");
> @@ -4506,11 +4511,21 @@ void qemu_init(int argc, char **argv, char **envp)
>      qemu_resolve_machine_memdev();
>      parse_numa_opts(current_machine);
>  
> +    if (preconfig_requested) {
> +        qemu_init_displays();
> +    }
> +
>      /* do monitor/qmp handling at preconfig state if requested */
>      qemu_main_loop();
>  
>      qemu_init_board();
> +
>      qemu_create_cli_devices();
> +
> +    /* initialize displays after all errors have been reported */
> +    if (!preconfig_requested) {
> +        qemu_init_displays();
> +    }
>      qemu_machine_creation_done();
>  
>      if (loadvm) {