Re: [PATCH 7/7] qemu-options: Remove mentions of legacy '-machine foo,accel=bar'

[Daniel P . Berrangé]

On Tue, Dec 03, 2024 at 10:21:53AM +0100, Philippe Mathieu-Daudé wrote:
> Since commit 6f6e1698a68 ("vl: configure accelerators from -accel
> options") we prefer the '-accel bar' command line option.
> 
> The new form started to be documented in commit 8d4e9146b35 ("tcg:
> add options for enabling MTTCG"); it is safe to remove the mentions
> of the legacy option.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>  qemu-options.hx | 9 ---------
>  1 file changed, 9 deletions(-)
> 
> diff --git a/qemu-options.hx b/qemu-options.hx
> index dacc9790a4b..11f0aab1470 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -27,8 +27,6 @@ ERST
>  DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
>      "-machine [type=]name[,prop[=value][,...]]\n"
>      "                selects emulated machine ('-machine help' for list)\n"
> -    "                property accel=accel1[:accel2[:...]] selects 
> accelerator\n"
> -    "                supported accelerators are kvm, xen, hvf, nvmm, whpx or 
> tcg (default: tcg)\n"
>      "                vmport=on|off|auto controls emulation of vmport 
> (default: auto)\n"
>      "                dump-guest-core=on|off include guest memory in a core 
> dump (default=on)\n"
>      "                mem-merge=on|off controls memory merge support 
> (default: on)\n"
> @@ -59,13 +57,6 @@ SRST
>  
>      Supported machine properties are:
>  
> -    ``accel=accels1[:accels2[:...]]``
> -        This is used to enable an accelerator. Depending on the target
> -        architecture, kvm, xen, hvf, nvmm, whpx or tcg can be available.
> -        By default, tcg is used. If there is more than one accelerator
> -        specified, the next one is used if the previous one fails to
> -        initialize.
> -

I'm not convinced we should be removing documentation for options that
currently exist and remain supported.

The documentation should be updated to say that we prefer use of '-accel'
instead at least.

Beyond that, what is our long term intention with '-machine accel=xxx' ?

Is this a case where we are happy to leave '-machine accel=' as syntax
sugar forever ?  Or is this a case where we want to deprecate it and
eventually remove its impl (and thus the documention here)

>      ``vmport=on|off|auto``
>          Enables emulation of VMWare IO port, for vmmouse etc. auto says
>          to select the value based on accel and i8042. For accel=xen or
> -- 
> 2.45.2
> 

With regards,
Daniel
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