[PATCH] hw/intc/arm_gicv3: ICC_HPPIR* return SPURIOUS if int group is disabled

[Peter Maydell]

If the group of the highest priority pending interrupt is disabled
via ICC_IGRPEN*, the ICC_HPPIR* registers should return
INTID_SPURIOUS, not the interrupt ID.  (See the GIC architecture
specification pseudocode functions ICC_HPPIR1_EL1[] and
HighestPriorityPendingInterrupt().)

Make HPPIR reads honour the group disable, the way we already do
when determining whether to preempt in icc_hppi_can_preempt().

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
Pre-existing bug which I happened to notice while working
on review of the FEAT_NMI patches. I don't suppose real world
code disables interrupt groups which it's actually using, which
is why nobody's noticed it. Still, it's a safe bugfix so might
as well go to stable too.
---
 hw/intc/arm_gicv3_cpuif.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/intc/arm_gicv3_cpuif.c b/hw/intc/arm_gicv3_cpuif.c
index e1a60d8c15b..67d8fd07b7f 100644
--- a/hw/intc/arm_gicv3_cpuif.c
+++ b/hw/intc/arm_gicv3_cpuif.c
@@ -1067,7 +1067,7 @@ static uint64_t icc_hppir0_value(GICv3CPUState *cs, 
CPUARMState *env)
      */
     bool irq_is_secure;
 
-    if (cs->hppi.prio == 0xff) {
+    if (icc_no_enabled_hppi(cs)) {
         return INTID_SPURIOUS;
     }
 
@@ -1104,7 +1104,7 @@ static uint64_t icc_hppir1_value(GICv3CPUState *cs, 
CPUARMState *env)
      */
     bool irq_is_secure;
 
-    if (cs->hppi.prio == 0xff) {
+    if (icc_no_enabled_hppi(cs)) {
         return INTID_SPURIOUS;
     }
 
-- 
2.34.1