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

["Sebastian Herbszt" <herbszt@gmx.de>]

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).

> +        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.

> +#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