RE: [RFC]RE: [PATCH] kvm-ia64 irq assignment 1/2 kernel

Xu, Anthony
2008-06-12T16:20:38Z

Avi Kivity wrote:
> Xu, Anthony wrote:
>> Thanks for comments
>>
>> Basically we are on the same page, while I didn't find your patch
>> about irq assignment, can you post it in this thread again, thx?
>> Below patch makes all PCI devices use level-trigger , active low
>> interrupt, it worked well when running linux guest, I didn't try
>> windows guest yet. (didn't have windows image in hand)
>>
>> Please comment!
>>
>> If this is acceptabled, we can figure out how to use IOAPIC in
>> kvm/ia32 based on this. Which will reduce irq sharing dramatically.
>>
>>
>> Thanks,
>> Anthony
>>
>>
>>
>> diff --git a/bios/acpi-dsdt.dsl b/bios/acpi-dsdt.dsl
>> index 21fc76a..4b5e824 100755
>> --- a/bios/acpi-dsdt.dsl
>> +++ b/bios/acpi-dsdt.dsl
>> @@ -974,7 +974,7 @@ DefinitionBlock (
>> Name(_HID, EISAID("PNP0C0F")) // PCI interrupt
>> link Name(_UID, 1)
>> Name(_PRS, ResourceTemplate(){
>> - Interrupt (, Level, ActiveHigh, Shared)
>> + Interrupt (, Level, ActiveLow, Shared)
>> { 5, 10, 11 }
>>
>
> I think this will fail for guests which use the PIC, since the PIC is
> always active high.
>
> For x86 the interrupts will have to be active high since that's how
> piix works.

Understand this concern.

Anthony