Re: [Qemu-devel] [PATCH] console: extend screendump monitor cmd

[Luiz Capitulino <lcapitulino@redhat.com>]

On Wed, 12 Jun 2013 13:51:17 +0200
Gerd Hoffmann <kraxel@redhat.com> wrote:

> Add an optional device parameter to the screendump command.
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=903910
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  hmp-commands.hx  |    6 +++---
>  hmp.c            |    3 ++-
>  qapi-schema.json |    4 +++-
>  qmp-commands.hx  |    3 ++-
>  ui/console.c     |   17 ++++++++++++++++-
>  5 files changed, 26 insertions(+), 7 deletions(-)
> 
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index 6991a97..5a44bda 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -237,9 +237,9 @@ ETEXI
>  
>      {
>          .name       = "screendump",
> -        .args_type  = "filename:F",
> -        .params     = "filename",
> -        .help       = "save screen into PPM image 'filename'",
> +        .args_type  = "filename:F,device:B?",
> +        .params     = "filename [device]",
> +        .help       = "save screen from device into PPM image 'filename'",
>          .mhandler.cmd = hmp_screen_dump,
>      },
>  
> diff --git a/hmp.c b/hmp.c
> index 55f195f..21fb37e 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -1344,9 +1344,10 @@ err_out:
>  void hmp_screen_dump(Monitor *mon, const QDict *qdict)
>  {
>      const char *filename = qdict_get_str(qdict, "filename");
> +    const char *device = qdict_get_try_str(qdict, "device");
>      Error *err = NULL;
>  
> -    qmp_screendump(filename, &err);
> +    qmp_screendump(filename, device != NULL, device, &err);
>      hmp_handle_error(mon, &err);
>  }
>  
> diff --git a/qapi-schema.json b/qapi-schema.json
> index adcf801..6cfccf4 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -3117,12 +3117,14 @@
>  # Write a PPM of the VGA screen to a file.
>  #
>  # @filename: the path of a new PPM file to store the image
> +# @device: #optional device to take the screenshot from
>  #
>  # Returns: Nothing on success
>  #
>  # Since: 0.14.0
>  ##
> -{ 'command': 'screendump', 'data': {'filename': 'str'} }
> +{ 'command': 'screendump', 'data': {'filename': 'str',
> +                                    '*device' : 'str'} }

We can't add new optional parameters to QMP commands because it's
currently impossible for mngt apps to discover them.

We have two options: 1. add this as a new command or 2. wait for
full schema introspection (which we might get for 1.6).

>  
>  ##
>  # @nbd-server-start:
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 8e69fba..27b138d 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -145,7 +145,7 @@ EQMP
>  
>      {
>          .name       = "screendump",
> -        .args_type  = "filename:F",
> +        .args_type  = "filename:F,device:B?",
>          .mhandler.cmd_new = qmp_marshal_input_screendump,
>      },
>  
> @@ -158,6 +158,7 @@ Save screen into PPM image.
>  Arguments:
>  
>  - "filename": file path (json-string)
> +- "device": video device (json-string, optional)
>  
>  Example:
>  
> diff --git a/ui/console.c b/ui/console.c
> index 07d4d63..a1401f2 100644
> --- a/ui/console.c
> +++ b/ui/console.c
> @@ -313,10 +313,25 @@ write_err:
>      goto out;
>  }
>  
> -void qmp_screendump(const char *filename, Error **errp)
> +void qmp_screendump(const char *filename,
> +                    bool has_device, const char *device, Error **errp)
>  {
>      QemuConsole *con = qemu_console_lookup_by_index(0);
>      DisplaySurface *surface;
> +    DeviceState *dev;
> +
> +    if (has_device) {
> +        dev = qdev_find_recursive(sysbus_get_default(), device);
> +        if (NULL == dev) {
> +            error_set(errp, QERR_DEVICE_NOT_FOUND, device);
> +            return;
> +        }
> +        con = qemu_console_lookup_by_device(dev);
> +        if (NULL == con) {
> +            error_setg(errp, "There is no QemuConsole linked to %s", device);
> +            return;
> +        }
> +    }
>  
>      if (con == NULL) {
>          error_setg(errp, "There is no QemuConsole I can screendump from.");