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

[Beth Kon]

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 <address@hidden>
> >
> > 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