Re: [PATCH] qemu-kvm-x86: consider the irq0override flag in kvm_arch_init_irq_routing

[Jan Kiszka <jan.kiszka@siemens.com>]

Hi Bernhard,

On 2010-09-14 15:51, Bernhard Kohl wrote:
> The setting of the irq0override flag must be also passed properly
> to the KVM_IRQCHIP_IOAPIC.
> 
> Signed-off-by: Bernhard Kohl <bernhard.kohl@nsn.com>
> ---
>  qemu-kvm-x86.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c
> index fd974b3..e35c234 100644
> --- a/qemu-kvm-x86.c
> +++ b/qemu-kvm-x86.c
> @@ -1388,9 +1388,9 @@ int kvm_arch_init_irq_routing(void)
>              }
>          }
>          for (i = 0; i < 24; ++i) {
> -            if (i == 0) {
> +            if (i == 0 && irq0override) {
>                  r = kvm_add_irq_route(kvm_context, i, KVM_IRQCHIP_IOAPIC, 2);
> -            } else if (i != 2) {
> +            } else if (i != 2 || !irq0override) {
>                  r = kvm_add_irq_route(kvm_context, i, KVM_IRQCHIP_IOAPIC, i);
>              }
>              if (r < 0) {

While cleaning up the irq0override fragments, I stumbled over this
commit. It is a nop for qemu-kvm, today and also by the time it was applied:

irq0override = !kvm_irqchip || kvm_has_gsi_routing

But, for obvious reasons, the code above is only executed when gsi
routing is available.

Can you remember what motivated this patch?

Jan

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