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

[Anthony Liguori <anthony@codemonkey.ws>]

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.

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;
>
>
>
>