[libvirt] [Qemu-devel] [RFC PATCH 2/4] qmp/hmp: Add getfd_file monitor command

[Stefan Hajnoczi]

On Mon, May 21, 2012 at 9:19 PM, Corey Bryant <coreyb at linux.vnet.ibm.com> wrote:
I think Eric has raised the main questions about duplicating getfd and
rules regarding canonical file names (QEMU mashes filenames together
if the backing filename is relative!).

> +    if (qemu_isdigit(filename[0])) {
> +        qerror_report(QERR_INVALID_PARAMETER_VALUE, "filename",
> +                      "a name not starting with a digit");
> +        return -1;
> +    }

What is the reason for this filename restriction?

> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index db980fa..1825a91 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -891,6 +891,36 @@ Example:
>  EQMP
>
>     {
> +        .name       = "getfd_file",
> +        .args_type  = "filename:s",
> +        .params     = "getfd_file filename",
> +        .help       = "receive a file descriptor via SCM rights and assign it a filename",
> +        .user_print = monitor_user_noop,
> +        .mhandler.cmd_new = do_getfd_file,
> +    },
> +
> +
> +SQMP
> +
> +getfd_file
> +--------------
> +
> +Receive a file descriptor via SCM rights and assign it a filename.
> +
> +Arguments:
> +
> +- "filename": filename (json-string)
> +
> +Example:
> +
> +-> { "execute": "getfd_file",
> +                "arguments": { "filename": "/var/lib/libvirt/images/tst.img" } }
> +<- { "return": {} }
> +
> +
> +EQMP

QMP commands should be added to qapi-schema.json as described in
docs/writing-qmp-commands.txt.

Stefan