Re: [Qemu-devel] Re: [PATCH] Fix non-ACPI Timer Interrupt Routing - v2

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

Sebastian Herbszt wrote:
> Beth Kon wrote:
>> Replicate ACPI irq0->inti2 override in mp table for non-acpi case.
>>
>> v1 -> v2 adds comment suggested by Ryan.
>>
>> Signed-off-by: Beth Kon <eak@us.ibm.com>
>>
>> diff --git a/bios/BIOS-bochs-latest b/bios/BIOS-bochs-latest
>> index ebec71b..82d7792 100644
>> Binary files a/bios/BIOS-bochs-latest and b/bios/BIOS-bochs-latest 
>> differ
>> diff --git a/bios/rombios32.c b/bios/rombios32.c
>> index 7be4216..dc7b5f3 100644
>> --- a/bios/rombios32.c
>> +++ b/bios/rombios32.c
>> @@ -1168,6 +1168,12 @@ static void mptable_init(void)
>>
>>     /* irqs */
>>     for(i = 0; i < 16; i++) {
>> +#ifdef BX_QEMU
>> +        /* One entry per ioapic input. Input 2 is covered by 
>> +           irq0->inti2 override (i == 0). irq 2 is unused */
>
> Isn't the input 0 or destination 2 covered by the override?
> We connect irq0 (input) to intin2 (destination).
In the comment I was using the terminology in the MP Specification, 
section 4.3.4. "Destination" 2 is the input to IOAPIC pin 2.  If you 
find it very confusing I can clarify.
>
>> +        if (i == 2)
>> +            continue;
>
> This changes the entry count. Currently it's
>
> putle16(&q, smp_cpus + 18); /* entry count */
>
> which is smp_cpus processor entries + (bus entry + i/o apic entry + 16 
> irq entries).
> This changes the number of irq entries to 15.
Yes, this was an oversight. Thanks!
>> +#endif                putb(&q, 3); /* entry type = I/O interrupt */
>>         putb(&q, 0); /* interrupt type = vectored interrupt */
>>         putb(&q, 0); /* flags: po=0, el=0 */
>> @@ -1175,7 +1181,11 @@ static void mptable_init(void)
>>         putb(&q, 0); /* source bus ID = ISA */
>>         putb(&q, i); /* source bus IRQ */
>>         putb(&q, ioapic_id); /* dest I/O APIC ID */
>> +#ifdef BX_QEMU
>> +        putb(&q, i == 0 ? 2 : i); /* dest I/O APIC interrupt in */
>> +#else
>>         putb(&q, i); /* dest I/O APIC interrupt in */
>> +#endif            }
>>     /* patch length */
>>     len = q - mp_config_table;
>
> - Sebastian
>
>
>