[Qemu-devel] Re: [PATCH] Seabios irq override support.

[Beth Kon <eak@us.ibm.com>]

Jes Sorensen wrote:
> On 07/25/2009 03:56 AM, Kevin O'Connor wrote:
>> On Fri, Jul 24, 2009 at 03:07:12PM +0200, Jes Sorensen wrote:
>>> With this patch applied, I can boot KVM using the latest upstream QEMU
>>> and Seabios.
>>
>> Thanks Jes.
>>
>> The bochs commit shows this wrapped in "#ifdef BX_QEMU".  Will this
>> patch break bochs, or were the ifdefs just bochs paranoia?
>
> Hi Kevin,
>
> I don't actually know for sure. I didn't add the #ifdefs since I got the
> impression that Seabios doesn't have them in many places. The original
> code was designed by Beth Kon, so maybe she can comment on whether we
> should add them to Seabios.
>
> Beth?
>
> Thanks,
> Jes
Hi Jes. These bios changes rely on matching userspace/kernel changes 
that translate irq0->inti2. So assuming seabios is used for systems 
other than kvm and qemu, this code would need to be conditionally removed.

But I'm not clear on what you're doing with this patch. You didn't 
include the irq0override flag that is needed by kvm because there are 
circumstances under which kvm turns off irq0override (i.e., old kernels 
that don't support irq routing). So this patch is fine for qemu, since 
it is permanently enabled there, but it is not a permanent solution for kvm.