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" <gso...@gmail.com>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
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;
