KVM: powerpc: Improve DEC handling
We treated the DEC interrupt like an edge based one. This is not true for
Book3s. The DEC keeps firing until mtdec is issued again and thus clears
the interrupt line.
So let's implement this logic in KVM too. This patch moves the line clearing
from the firing of the interrupt to the mtdec emulation.
This makes PPC64 guests work without AGGRESSIVE_DEC defined.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Acked-by: Hollis Blanchard <hollis@penguinppc.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 241795b..fd3ad6c 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -151,6 +151,13 @@
return prio;
}
+static void kvmppc_book3s_dequeue_irqprio(struct kvm_vcpu *vcpu,
+ unsigned int vec)
+{
+ clear_bit(kvmppc_book3s_vec2irqprio(vec),
+ &vcpu->arch.pending_exceptions);
+}
+
void kvmppc_book3s_queue_irqprio(struct kvm_vcpu *vcpu, unsigned int vec)
{
vcpu->stat.queue_intr++;
@@ -178,6 +185,11 @@
return test_bit(BOOK3S_INTERRUPT_DECREMENTER >> 7, &vcpu->arch.pending_exceptions);
}
+void kvmppc_core_dequeue_dec(struct kvm_vcpu *vcpu)
+{
+ kvmppc_book3s_dequeue_irqprio(vcpu, BOOK3S_INTERRUPT_DECREMENTER);
+}
+
void kvmppc_core_queue_external(struct kvm_vcpu *vcpu,
struct kvm_interrupt *irq)
{
@@ -275,7 +287,9 @@
#endif
priority = __ffs(*pending);
while (priority <= (sizeof(unsigned int) * 8)) {
- if (kvmppc_book3s_irqprio_deliver(vcpu, priority)) {
+ if (kvmppc_book3s_irqprio_deliver(vcpu, priority) &&
+ (priority != BOOK3S_IRQPRIO_DECREMENTER)) {
+ /* DEC interrupts get cleared by mtdec */
clear_bit(priority, &vcpu->arch.pending_exceptions);
break;
}