diff mbox series

[v1,1/5] openpic: Preserve IRQs masked by CTPR

Message ID 20260827155310.7223-2-kirill@korins.ky
State New
Headers show
Series mac99: Boot OpenBSD/macppc | expand

Commit Message

Kirill A. Korinsky Aug. 27, 2026, 3:50 p.m. UTC 
OpenBSD exposes this by raising CTPR while handling interrupts. If an
edge remains pending when EOI lowers the servicing priority, QEMU
reasserts INT without checking CTPR; IACK then returns the spurious
vector and consumes the masked edge before CTPR permits delivery.

Signed-off-by: Kirill A. Korinsky <kirill@korins.ky>
---
 hw/intc/openpic.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/hw/intc/openpic.c b/hw/intc/openpic.c
index 99d2a1e65e..6f9a562163 100644
--- a/hw/intc/openpic.c
+++ b/hw/intc/openpic.c
@@ -1033,8 +1033,9 @@  static void openpic_cpu_write_internal(void *opaque, hwaddr addr,
         n_IRQ = IRQ_get_next(opp, &dst->raised);
         if (n_IRQ != -1) {
             src = &opp->src[n_IRQ];
-            if (s_IRQ == -1 ||
-                IVPR_PRIORITY(src->ivpr) > dst->servicing.priority) {
+            if (IVPR_PRIORITY(src->ivpr) > dst->ctpr &&
+                (s_IRQ == -1 ||
+                 IVPR_PRIORITY(src->ivpr) > dst->servicing.priority)) {
                 DPRINTF("Raise OpenPIC INT output cpu %d irq %d",
                         idx, n_IRQ);
                 qemu_irq_raise(opp->dst[idx].irqs[OPENPIC_OUTPUT_INT]);
@@ -1070,12 +1071,13 @@  static uint32_t openpic_iack(OpenPICState *opp, IRQDest *dst, int cpu)
     }
 
     src = &opp->src[irq];
-    if (!(src->ivpr & IVPR_ACTIVITY_MASK) ||
-            !(IVPR_PRIORITY(src->ivpr) > dst->ctpr)) {
+    if (!(src->ivpr & IVPR_ACTIVITY_MASK)) {
         error_report("%s: bad raised IRQ %d ctpr %d ivpr 0x%08x",
                 __func__, irq, dst->ctpr, src->ivpr);
         openpic_update_irq(opp, irq);
         retval = opp->spve;
+    } else if (IVPR_PRIORITY(src->ivpr) <= dst->ctpr) {
+        return opp->spve;
     } else {
         /* IRQ enter servicing state */
         IRQ_setbit(&dst->servicing, irq);