summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kvm/book3s_xive.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kvm/book3s_xive.c')
-rw-r--r--arch/powerpc/kvm/book3s_xive.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index 586867e46e51..591bfb4bfd0f 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -166,6 +166,9 @@ static irqreturn_t xive_esc_irq(int irq, void *data)
*/
vcpu->arch.xive_esc_on = false;
+ /* This orders xive_esc_on = false vs. subsequent stale_p = true */
+ smp_wmb(); /* goes with smp_mb() in cleanup_single_escalation */
+
return IRQ_HANDLED;
}
@@ -1119,6 +1122,31 @@ void kvmppc_xive_disable_vcpu_interrupts(struct kvm_vcpu *vcpu)
vcpu->arch.xive_esc_raddr = 0;
}
+/*
+ * In single escalation mode, the escalation interrupt is marked so
+ * that EOI doesn't re-enable it, but just sets the stale_p flag to
+ * indicate that the P bit has already been dealt with. However, the
+ * assembly code that enters the guest sets PQ to 00 without clearing
+ * stale_p (because it has no easy way to address it). Hence we have
+ * to adjust stale_p before shutting down the interrupt.
+ */
+void xive_cleanup_single_escalation(struct kvm_vcpu *vcpu,
+ struct kvmppc_xive_vcpu *xc, int irq)
+{
+ struct irq_data *d = irq_get_irq_data(irq);
+ struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+
+ /*
+ * This slightly odd sequence gives the right result
+ * (i.e. stale_p set if xive_esc_on is false) even if
+ * we race with xive_esc_irq() and xive_irq_eoi().
+ */
+ xd->stale_p = false;
+ smp_mb(); /* paired with smb_wmb in xive_esc_irq */
+ if (!vcpu->arch.xive_esc_on)
+ xd->stale_p = true;
+}
+
void kvmppc_xive_cleanup_vcpu(struct kvm_vcpu *vcpu)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
@@ -1143,6 +1171,9 @@ void kvmppc_xive_cleanup_vcpu(struct kvm_vcpu *vcpu)
/* Free escalations */
for (i = 0; i < KVMPPC_XIVE_Q_COUNT; i++) {
if (xc->esc_virq[i]) {
+ if (xc->xive->single_escalation)
+ xive_cleanup_single_escalation(vcpu, xc,
+ xc->esc_virq[i]);
free_irq(xc->esc_virq[i], vcpu);
irq_dispose_mapping(xc->esc_virq[i]);
kfree(xc->esc_virq_names[i]);