[Qemu-devel] Re: [RFC][PATCH] disable special ioapic inti0 routing

[Anthony Liguori <anthony@codemonkey.ws>]

Jan Kiszka wrote:
> Anthony Liguori wrote:
>   
>> Jan Kiszka wrote:
>>     
>>> This patch comes from the kvm tree and fixes the timer IRQ routing for
>>> me which is broken from the POV of certain Linux guest kernels. As I'm
>>> not up-to-date with the development around that problematic hunk, I'm
>>> leaving it to someone more deeply involved to sign this off. But please
>>> commit some fix.
>>>   
>>>       
>> Are you using an old bios by chance?  The reason this fixes KVM has
>> nothing to do with QEMU FWIW so if this fixes something for you, it's
>> just a coincidence.
>>     
>
> My first thought as well, but the binary bios from latest svn made no
> difference.
>   

What linux guests broke?

Regards,

Anthony Liguori

> Jan
>
>   
>> Regards,
>>
>> Anthony Liguroi
>>
>>     
>>> Thanks,
>>> Jan
>>>
>>> ------->
>>>
>>> From: Avi Kivity <avi@redhat.com>
>>>
>>> we don't support it yet (need bios support, and modifications to kernel
>>> irq routing).
>>>
>>> ---
>>>  qemu/hw/apic.c |    2 ++
>>>  1 files changed, 2 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/qemu/hw/apic.c b/qemu/hw/apic.c
>>> index df80444..f9ef995 100644
>>> --- a/qemu/hw/apic.c
>>> +++ b/qemu/hw/apic.c
>>> @@ -1055,12 +1055,14 @@ void ioapic_set_irq(void *opaque, int vector,
>>> int level)
>>>  {
>>>      IOAPICState *s = opaque;
>>>  
>>> +#if 0
>>>      /* ISA IRQs map to GSI 1-1 except for IRQ0 which maps
>>>       * to GSI 2.  GSI maps to ioapic 1-1.  This is not
>>>       * the cleanest way of doing it but it should work. */
>>>  
>>>      if (vector == 0)
>>>          vector = 2;
>>> +#endif
>>>  
>>>      if (vector >= 0 && vector < IOAPIC_NUM_PINS) {
>>>          uint32_t mask = 1 << vector;
>>>
>>>
>>>
>>>   
>>>       
>>
>>
>>     
>
>
>