Re: [PATCH v2] qemu-option: do not suggest using the delay option

[Markus Armbruster <armbru@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> The "delay" option was a hack that was introduced to allow writing "nodelay".
> We are adding a "nodelay" option to be used as "nodelay=on", so recommend it
> instead of "delay".
>
> This is quite ugly, but a proper deprecation of "delay"
> cannot be done if QEMU starts suggesting it.  Since it's the
> only case I opted for this very much ad-hoc patch.
>
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  docs/system/deprecated.rst | 6 ++++++
>  util/qemu-option.c         | 6 +++++-
>  2 files changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst
> index fcf0ca4068..cfabe69846 100644
> --- a/docs/system/deprecated.rst
> +++ b/docs/system/deprecated.rst
> @@ -134,6 +134,12 @@ Boolean options such as ``share=on``/``share=off`` could be written
>  in short form as ``share`` and ``noshare``.  This is now deprecated
>  and will cause a warning.
>  
> +``delay`` option for socket character devices (since 6.0)
> +'''''''''''''''''''''''''''''''''''''''''''''''''''''''''
> +
> +The replacement for the ``nodelay`` short-form boolean option is ``nodelay=on``
> +rather than ``delay=off``.
> +
>  ``--enable-fips`` (since 6.0)
>  '''''''''''''''''''''''''''''
>  
> diff --git a/util/qemu-option.c b/util/qemu-option.c
> index 40564a12eb..9678d5b682 100644
> --- a/util/qemu-option.c
> +++ b/util/qemu-option.c
> @@ -785,7 +785,11 @@ static const char *get_opt_name_value(const char *params,
>              }
>              if (!is_help && warn_on_flag) {
>                  warn_report("short-form boolean option '%s%s' deprecated", prefix, *name);
> -                error_printf("Please use %s=%s instead\n", *name, *value);
> +                if (g_str_equal(*name, "delay")) {
> +                    error_printf("Please use nodelay=%s instead\n", prefix[0] ? "on" : "off");
> +                } else {
> +                    error_printf("Please use %s=%s instead\n", *name, *value);
> +                }
>              }
>          }
>      } else {

I agree it's ugly, but I don't have better ideas, and it'll go away
eventually.

The warning gets emitted for any QemuOpts parameter named "delay" used
without a value, not just socket chardev's parameter.  Could result in
somewhat misleading warnings, but trying to avoid them seems a waste of
our time.

Should we mention this in the commit message?  Or even in a code
comment?  Up do you.

Reviewed-by: Markus Armbruster <armbru@redhat.com>