Re: [Qemu-devel] [PATCH v4 7/7] hw/i386: build ACPI MADT (APIC) for fw_cfg clients

[Laszlo Ersek]

On 04/29/13 14:39, Kevin O'Connor wrote:
> On Mon, Apr 29, 2013 at 11:20:15AM +0300, Michael S. Tsirkin wrote:

>> in particular, seabios wants to interpret presence
>> of any file in etc/acpi as a signal not to generate
>> its own tables.
> 
> Right.

In that case,

>> So merging this patch but without the config option will break
>> this plan. The only two ways I see are:
>> - merge this last patch with the config option, disabled by default
>>   the idea being we can improve it in-tree, gradually.
>> - keep this patch out of tree until we have a complete
>>   set of tables.
>>
>> Both are fine with me.
> 
> Why?  As long as QEMU places the new tables under new fwcfg entries,
> old seabios will totally ignore the new tables.  I don't see why a
> QEMU config option is needed - it's safe for QEMU to always create
> both old and new fwcfg entries.

the new-style fw_cfg entry for the MADT (= "etc/acpi/APIC") would
prevent the generation of all other (yet unexported by qemu) ACPI tables
in *new* seabios.

[SeaBIOS] [PATCH RFC 2/3] acpi: load and link tables from /etc/acpi/
<http://thread.gmane.org/gmane.comp.emulators.qemu/208457/focus=208458>

Thanks,
Laszlo