Re: [Qemu-devel] [PATCH 4/4] HMP: Introduce console command

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri, 26 Oct 2012 19:21:52 +0800
Lei Li <lilei@linux.vnet.ibm.com> wrote:

> Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>

I still don't understand how this command, in its current form, is
different from memchar-write.

One more comment below.

> ---
>  hmp-commands.hx |   25 +++++++++++++++++++++++++
>  hmp.c           |   52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  hmp.h           |    1 +
>  monitor.c       |   15 +++++++++++++++
>  monitor.h       |    3 +++
>  5 files changed, 96 insertions(+), 0 deletions(-)
> 
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index df294eb..7cba42c 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -861,6 +861,31 @@ if the requested size is larger than it.
>  ETEXI
>  
>      {
> +        .name       = "console",
> +        .args_type  = "chardev:s",
> +        .params     = "chardev",
> +        .help       = "Connect to the serial console from within the"
> +                      "monitor, allow to write data to memchardev"
> +                      "'chardev'. Exit from the console and return back"
> +                      "to monitor by typing 'ctrl-]'",
> +        .mhandler.cmd = hmp_console,
> +    },
> +
> +STEXI
> +@item console @var{device}
> +@findex console
> +
> +Connect to the serial console from within the monitor, allow to write data
> +to memchardev @var{chardev}. Exit from the console and return back to
> +monitor by typing 'ctrl-]'.
> +@example
> +(qemu) console foo
> +foo: data string...
> +@end example
> +
> +ETEXI
> +
> +    {
>          .name       = "migrate",
>          .args_type  = "detach:-d,blk:-b,inc:-i,uri:s",
>          .params     = "[-d] [-b] [-i] uri",
> diff --git a/hmp.c b/hmp.c
> index ef85736..d716410 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -1255,3 +1255,55 @@ void hmp_screen_dump(Monitor *mon, const QDict *qdict)
>      qmp_screendump(filename, &err);
>      hmp_handle_error(mon, &err);
>  }
> +
> +enum escape_char
> +{
> +    ESCAPE_CHAR_CTRL_GS = 0x1d  /* ctrl-] used for escape */
> +};
> +
> +static void hmp_read_console(Monitor *mon, const char *data,
> +                             void *opaque)
> +{
> +    CharDriverState *chr = opaque;
> +    uint32_t size = strlen(data);
> +    enum DataFormat format = DATA_FORMAT_UTF8;
> +    enum escape_char console_escape = ESCAPE_CHAR_CTRL_GS;
> +
> +    Error *err = NULL;
> +
> +    if (*data == console_escape) {
> +        monitor_resume(mon);
> +        return;
> +    }
> +
> +    qmp_memchar_write(chr->label, size, data, 0, format, &err);
> +
> +    if (err) {
> +        monitor_printf(mon, "%s\n", error_get_pretty(err));
> +        error_free(err);
> +        return;
> +    }
> +
> +    monitor_read_command(mon, 1);
> +}
> +
> +void hmp_console(Monitor *mon, const QDict *qdict)
> +{
> +    const char *device = qdict_get_str(qdict, "chardev");
> +    CharDriverState *chr;
> +    Error *err = NULL;
> +
> +    chr = qemu_chr_find(device);
> +
> +    if (!chr) {
> +        error_set(&err, QERR_DEVICE_NOT_FOUND, device);
> +        goto out;
> +    }

As I said before, I don't why chr is needed. It seems to me that passing
'device' down is enough.

> +
> +    if (monitor_read_console(mon, device, hmp_read_console, chr) < 0) {
> +        monitor_printf(mon, "Connect to console %s failed\n", device);
> +    }
> +
> +out:
> +    hmp_handle_error(mon, &err);
> +}
> diff --git a/hmp.h b/hmp.h
> index a5a0cfe..5b54a79 100644
> --- a/hmp.h
> +++ b/hmp.h
> @@ -77,5 +77,6 @@ void hmp_getfd(Monitor *mon, const QDict *qdict);
>  void hmp_closefd(Monitor *mon, const QDict *qdict);
>  void hmp_send_key(Monitor *mon, const QDict *qdict);
>  void hmp_screen_dump(Monitor *mon, const QDict *qdict);
> +void hmp_console(Monitor *mon, const QDict *qdict);
>  
>  #endif
> diff --git a/monitor.c b/monitor.c
> index d17ae2d..7e90115 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -256,6 +256,21 @@ int monitor_read_password(Monitor *mon, ReadLineFunc *readline_func,
>      }
>  }
>  
> +int monitor_read_console(Monitor *mon, const char *device,
> +                         ReadLineFunc *readline_func, void *opaque)
> +{
> +    char prompt[60];
> +
> +    if (!mon->rs) {
> +        return -1;
> +    }
> +
> +    snprintf(prompt, sizeof(prompt), "%s: ", device);
> +    readline_start(mon->rs, prompt, 0, readline_func, opaque);
> +
> +    return 0;
> +}
> +
>  void monitor_flush(Monitor *mon)
>  {
>      if (mon && mon->outbuf_index != 0 && !mon->mux_out) {
> diff --git a/monitor.h b/monitor.h
> index b6e7d95..735bd1b 100644
> --- a/monitor.h
> +++ b/monitor.h
> @@ -86,6 +86,9 @@ ReadLineState *monitor_get_rs(Monitor *mon);
>  int monitor_read_password(Monitor *mon, ReadLineFunc *readline_func,
>                            void *opaque);
>  
> +int monitor_read_console(Monitor *mon, const char *device,
> +                         ReadLineFunc *readline_func, void *opaque);
> +
>  int qmp_qom_set(Monitor *mon, const QDict *qdict, QObject **ret);
>  
>  int qmp_qom_get(Monitor *mon, const QDict *qdict, QObject **ret);