Re: [Qemu-devel] [PATCH 1/1] QMP: add snapshot_blkdev command

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri,  8 Jul 2011 14:00:13 +0200
Jes.Sorensen@redhat.com wrote:

> From: Jes Sorensen <Jes.Sorensen@redhat.com>
> 
> Add QMP bits for snapshot_blkdev command. This is the same as
> snapshot_blkdev in the human monitor. The command is synchronous.
> 
> In the future async commands and or a break down of the functionality
> into multiple commands might be added.
> 
> Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
> ---
>  qmp-commands.hx |   38 ++++++++++++++++++++++++++++++++++++++
>  1 files changed, 38 insertions(+), 0 deletions(-)
> 
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 92c5c3a..eb135c1 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -694,6 +694,44 @@ Example:
>  EQMP
>  
>      {
> +        .name       = "blockdev-snapshot",

blockdev-snapshot-sync.

> +        .args_type  = "device:B,snapshot_file:s?,format:s?",
> +        .params     = "device [new-image-file] [format]",
> +        .help       = "initiates a live snapshot\n\t\t\t"
> +                      "of device. If a new image file is specified, the\n\t\t\t"
> +                      "new image file will become the new root image.\n\t\t\t"
> +                      "If format is specified, the snapshot file will\n\t\t\t"
> +                      "be created in that format. Otherwise the\n\t\t\t"
> +                      "snapshot will be internal! (currently unsupported)",

The 'otherwise' part is a bit confusing. You document something as if it were
supported then you say it's not supported. I recommend to just not document it
instead.

> +        .user_print = monitor_user_noop,
> +        .mhandler.cmd_new = do_snapshot_blkdev,
> +    },
> +
> +SQMP
> +blockdev-snapshot-sync
> +----------------------
> +
> +Synchronous snapshot of block device, using snapshot file as target,
> +if provided. 

In QMP only this text is used, the text in '.help' is discarded. Please,
move all command documentation here.

> +
> +Arguments:
> +
> +- "device": device name to snapshot (json-string)
> +- "snapshot_file": name of new image file (json-string)
> +- "format": format of new image (json-string)
> +
> +Example:
> +
> +-> { "execute": "blockdev-snapshot", "arguments": { "device": "ide-hd0",
> +                                                    "snapshot_file":

We are trying to standardize the use of hyphen in QMP.

> +                                                    "/some/place/my-image",
> +						    "format": "qcow2"
> +                                                   } }
> +<- { "return": {} }
> +
> +EQMP
> +
> +    {
>          .name       = "balloon",
>          .args_type  = "value:M",
>          .params     = "target",