Re: [Qemu-devel] [PATCH v3 07/10] check: Only test boot-serial when sga is compiled in

[Thomas Huth]

On 2018-08-23 09:43, Gerd Hoffmann wrote:
>>> Reviewed-by: Thomas Huth <address@hidden>
>>>
>>> Off-topic: I wonder whether we could even deprecate the SGA device
>>> nowadays, since the main seabios now can redirect the console to the
>>> serial port, too?
>>
>> No idea, but then I think we can deprecate it, we already have enough
>> weird things around.
> 
> Deprecating sure.  Actually dropping is not so easy I think.  The switch
> is not transparent to the guest, which implies live migration
> compatibility isssues.
> 
> So the only thing we can do is blocking it for new machine types (3.1+).
> Then, in a bunch of years when we deprecate 3.1 & older machine types,
> we can actually remove it.
> 
> I remember we even discussed that a while back ...
> Oh yes: 
> https://git.kraxel.org/cgit/qemu/commit/?h=work/no-sgabios&id=408690999429fdf44011c49b3af6efa50f369b1e
> Somehow never ended up being merged.

Sounds like a good idea! Could you repost the patch, with an update to
qemu-deprecated.texi, please? Maybe also print the deprecation message
in any case if !use_sgabios, e.g.:

    if (sga->use_sgabios) {
        rom_add_vga(SGABIOS_FILENAME);
    } else if (machine->enable_graphics) {
        warn_report("sgabios is deprecated for your machine type, "
                    "please use -machine graphics=off instead of "
                    "-device sga");
        rom_add_vga(SGABIOS_FILENAME);
    } else {
        /*
         * For this machine type we expect SeaBIOS to provide a
         * serial console for -machine graphics=off.  No need to
         * add the sgabios rom here.
         */
        warn_report("sgabios is deprecated and is not required anymore,"
                    " SeaBIOS now has the same functionality, too");
    }

 Thomas