Re: [Qemu-devel] [PATCH for-1.5] Revert "pc: Kill the "use flash device for BIOS unless KVM" misfeature"

[Paolo Bonzini]

Il 15/05/2013 17:09, Markus Armbruster ha scritto:
>>>>> @@ -209,7 +209,7 @@ void pc_system_firmware_init(MemoryRegion *rom_memory)
>>>>>       * TODO This device exists only so that users can switch between
>>>>>       * use of flash and ROM for the BIOS.  The ability to switch was
>>>>>       * created because flash doesn't work with KVM.  Once it does, we
>>>>> -     * should drop this device for new machine types.
>>>>> +     * should drop this device.
>>>>>       */
>>>>>      sysfw_dev = (PcSysFwDevice*) qdev_create(NULL, "pc-sysfw");
>>>>>  
>>>
>>> Why did you change the comment?
>>
>> Because we agreed on the way forward for the flash patches, and it will
>> remove the need for (a) changes to machine types; (b) pc_sysfw in
>> general.  The device will be created iff a -pflash or -drive if=pflash
>> option is provided.  Thus in principle you could use -M pc-0.12 with
>> -pflash and it will work.
> 
> Yes, that's the way forward, and yes, that means we'll have no use for
> the "pc-sysfw" dummy device on new machine types.  But why can we
> retroactively delete it from existing machine types?

Because it would only affect TCG and people probably don't care much
about backwards-compatible machine types with TCG.  I'd rather remove
the misfeature completely and start from scratch with a sane design, now
that we have it.

Paolo