Re: [Qemu-devel] [PATCH v2] Print a warning message if the user specified a legacy USB option

[Paolo Bonzini <pbonzini@redhat.com>]

On 02/05/2017 10:07, Thomas Huth wrote:
> '-usb' and '-usbdevice' are considered as deprecated nowadays and
> we might want to remove these options in a future version of QEMU.
> So mark this options as deprecated in the documenation and print out
> a warning if they are used to tell the user what to use instead.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  v2: Also update the documentation accordingly
> 
>  qemu-options.hx | 8 +++++---
>  vl.c            | 4 ++++
>  2 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/qemu-options.hx b/qemu-options.hx
> index f68829f..57bacc5 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -946,12 +946,13 @@ STEXI
>  ETEXI
>  
>  DEF("usb", 0, QEMU_OPTION_usb,
> -    "-usb            enable the USB driver (will be the default soon)\n",
> +    "-usb            enable the USB driver (if it is not used by default yet)\n",
>      QEMU_ARCH_ALL)
>  STEXI
>  @item -usb
>  @findex -usb
> -Enable the USB driver (will be the default soon)
> +Enable the USB driver (if it is not used by default yet). Note that this
> +option is deprecated, please use @code{-M usb=on} instead.

This is pointless, "-usb" is just syntactic sugar and doesn't add any
complex logic.

>  ETEXI
>  
>  DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
> @@ -961,7 +962,8 @@ STEXI
>  
>  @item -usbdevice @var{devname}
>  @findex -usbdevice
> -Add the USB device @var{devname}. @xref{usb_devices}.
> +Add the USB device @var{devname}. Note that this option is deperecated,
> +please use @code{-device usb-...} instead. See also @xref{usb_devices}.
>  
>  @table @option

This makes sense, but the usb_devices section of the manual still
documents -usbdevice instead of "-device usb-...".

In general, docs/qdev-device-use.txt should be integrated in the manual
before a serious attempt to deprecate "-usbdevice" and "-drive" is made.

Thanks,

Paolo

> diff --git a/vl.c b/vl.c
> index 42d4bce..0023298 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -3748,10 +3748,14 @@ int main(int argc, char **argv, char **envp)
>                  }
>                  break;
>              case QEMU_OPTION_usb:
> +                error_report("'-usb' is deprecated, please use "
> +                             "'-M usb=on' instead");
>                  olist = qemu_find_opts("machine");
>                  qemu_opts_parse_noisily(olist, "usb=on", false);
>                  break;
>              case QEMU_OPTION_usbdevice:
> +                error_report("'-usbdevice' is deprecated, please use "
> +                             "'-device usb-...' instead");
>                  olist = qemu_find_opts("machine");
>                  qemu_opts_parse_noisily(olist, "usb=on", false);
>                  add_device_config(DEV_USB, optarg);
>