[Qemu-devel] [PATCH v2 12/16] hw/intc/arm_gic: Change behavior of EOIR writes

[Greg Bellows <greg.bellows@linaro.org>]

From: Fabian Aggeler <aggelerf@ethz.ch>

Grouping (GICv2) and Security Extensions change the behavior of EOIR
writes. Completing Group0 interrupts is only allowed from Secure state
and completing Group1 interrupts from Secure state is only allowed if
AckCtl bit is set.

Signed-off-by: Fabian Aggeler <aggelerf@ethz.ch>

---

v1 -> v2
- Fix issue with EOIR writes involving AckCtl.  AckCtl is ignored on EOIR
  group 1 interrupts when non-secure.  Group 1 interrupts are only ignored when
  secure and AckCTl is clear.
---
 hw/intc/arm_gic.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c
index 15fd660..2d83225 100644
--- a/hw/intc/arm_gic.c
+++ b/hw/intc/arm_gic.c
@@ -384,6 +384,21 @@ void gic_complete_irq(GICState *s, int cpu, int irq)
             GIC_SET_PENDING(irq, cm);
             update = 1;
         }
+    } else if ((s->revision >= 2 && !s->security_extn)
+                 || (s->security_extn && !ns_access())) {
+        /* Handle GICv2 without Security Extensions or GIC with Security
+         * Extensions and a secure write.
+         */
+        if (!GIC_TEST_GROUP0(irq, cm) && !ns_access()
+                && !(s->cpu_control[cpu][0] & GICC_CTLR_S_ACK_CTL)) {
+            /* Unpredictable. We choose to ignore. */
+            DPRINTF("EOI for Group1 interrupt %d ignored "
+                    "(AckCtl disabled)\n", irq);
+            return;
+        }
+    } else if (s->security_extn && ns_access() && GIC_TEST_GROUP0(irq, cm)) {
+        DPRINTF("Non-secure EOI for Group0 interrupt %d ignored\n", irq);
+        return;
     }
 
     if (irq != s->running_irq[cpu]) {
-- 
1.8.3.2