On Thu, 2014-02-27 at 19:05 +0200, Michael S. Tsirkin wrote:
> apic polarity in KVM does not work: too many things assume active high.
> Let's not pretend it works, let's just ignore polarity flag. If we ever
> want to emulate it exactly, this will need a feature flag anyway.
>
> Also report this to userspace: this makes it
> possible to report the interrupt active-low
> in ACPI, this way we are closer to real hardware.
>
> This patch fixes OSX running on KVM.
>
> Reported-by: "Gabriel L. Somlo" <gsomlo@xxxxxxxxx>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
>
> ---
>
> Gabriel, could you confirm this fixes OSX for you?
> If you can play with linux tweaking interrupt
> to active low, that would be very nice too:
> it's weekend here.
>
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 902f124..db29b27 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -674,6 +676,7 @@ struct kvm_ppc_smmu_info {
> #define KVM_CAP_ARM_EL1_32BIT 93
> #define KVM_CAP_SPAPR_MULTITCE 94
> #define KVM_CAP_EXT_EMUL_CPUID 95
> +#define KVM_CAP_X86_IOAPIC_POLARITY_IGNORED 96
>
> #ifdef KVM_CAP_IRQ_ROUTING
>
> diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
> index 2d68297..ad170b4 100644
> --- a/virt/kvm/ioapic.c
> +++ b/virt/kvm/ioapic.c
> @@ -328,7 +328,6 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
> irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
> irq_source_id, level);
> entry = ioapic->redirtbl[irq];
> - irq_level ^= entry.fields.polarity;
> if (!irq_level) {
> ioapic->irr &= ~mask;
> ret = 1;
I've run Windows and Linux guests with vfio assigned devices with this
change and all the interrupt types seem to work.
Tested-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
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