Re: [Qemu-devel] [PATCH v2] stop using stdio for monitor/serial/etc with -daemonize

[Anthony Liguori <anthony@codemonkey.ws>]

Michael Tokarev <mjt@tls.msk.ru> writes:

> Current code binds monitor and serial port to the guest console
> unless -nographic is specified, which is okay.  But when there's
> no guest console (-nographic), the code tries to use stdio for
> the same default devices.  But it does not check for -daemonize
> at the same time -- because when -daemonize is given, there's no
> point at using stdin since it will be closed down the line.
> However, when serial port is attached to stdin, tty control
> modes are changed (switching tty to raw mode), and qemu will
> switch to background, leaving the tty in bad state.
>
> Take -daemonize into account too, when assigning default devices,
> and for -nographic -daemonize case, assign them to "null" instead.

Combining -nographic and -daemonize don't make sense.  I'd rather error
out with this combination.

I think what the user is after is -daemonize -vga none OR -daemonize
-display none.

Regards,

Anthony Liguori

>
> This is https://bugs.launchpad.net/qemu/+bug/1024275
> or http://bugs.debian.org/549195 .
>
> While at it, reformat this code a bit to be less of a maze of
> ifs and use a variable to hold common target of devices.
>
> This patch depends on another patch, 995ee2bf469de6,
> "curses: don't initialize curses when qemu is daemonized",
> by Hitoshi Mitake, which creates is_daemonized() routine.
>
> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
> ---
>  vl.c |   45 +++++++++++++++++++++++++++------------------
>  1 file changed, 27 insertions(+), 18 deletions(-)
>
> diff --git a/vl.c b/vl.c
> index 48049ef..a210ff9 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -3392,30 +3392,39 @@ int main(int argc, char **argv, char **envp)
>          default_sdcard = 0;
>      }
>  
> -    if (display_type == DT_NOGRAPHIC) {
> -        if (default_parallel)
> -            add_device_config(DEV_PARALLEL, "null");
> +    /* Create default monitor, serial, parallel and virtcon devices. */
> +    /* reuse optarg variable */
> +    optarg = NULL;
> +    if (display_type != DT_NOGRAPHIC) {
> +        /* regular case, all devices directed to the guest console */
> +        optarg = "vc:80Cx24C";
> +    } else if (is_daemonized()) {
> +        /* nographic and daemonize, everything => null */
> +        optarg = "null";
> +    } else {
> +        /* nographic and no daemonize */
> +        /* can't have both serial and virtcon on stdio */
>          if (default_serial && default_monitor) {
>              add_device_config(DEV_SERIAL, "mon:stdio");
>          } else if (default_virtcon && default_monitor) {
>              add_device_config(DEV_VIRTCON, "mon:stdio");
>          } else {
> -            if (default_serial)
> -                add_device_config(DEV_SERIAL, "stdio");
> -            if (default_virtcon)
> -                add_device_config(DEV_VIRTCON, "stdio");
> -            if (default_monitor)
> -                monitor_parse("stdio", "readline");
> +            optarg = "stdio";
>          }
> -    } else {
> -        if (default_serial)
> -            add_device_config(DEV_SERIAL, "vc:80Cx24C");
> -        if (default_parallel)
> -            add_device_config(DEV_PARALLEL, "vc:80Cx24C");
> -        if (default_monitor)
> -            monitor_parse("vc:80Cx24C", "readline");
> -        if (default_virtcon)
> -            add_device_config(DEV_VIRTCON, "vc:80Cx24C");
> +    }
> +    if (optarg && default_serial) {
> +        add_device_config(DEV_SERIAL, optarg);
> +    }
> +    if (default_parallel) {
> +        /* parallel port is connected console or to null */
> +        add_device_config(DEV_PARALLEL,
> +                          display_type == DT_NOGRAPHIC ? "null" : optarg);
> +    }
> +    if (optarg && default_monitor) {
> +        monitor_parse(optarg, "readline");
> +    }
> +    if (optarg && default_virtcon) {
> +        add_device_config(DEV_VIRTCON, optarg);
>      }
>  
>      socket_init();
> -- 
> 1.7.10.4