[PULL 05/17] hw/intc/arm_gicv3_cpuif: Fix virtual irq number check in icv_[dir|eoir]_write

[Peter Maydell]

From: Ricardo Koller <ricarkol@google.com>

icv_eoir_write() and icv_dir_write() ignore invalid virtual IRQ numbers
(like LPIs).  The issue is that these functions check against the number
of implemented IRQs (QEMU's default is num_irq=288) which can be lower
than the maximum virtual IRQ number (1020 - 1).  The consequence is that
if a hypervisor creates an LR for an IRQ between 288 and 1020, then the
guest is unable to deactivate the resulting IRQ. Note that other
functions that deal with large IRQ numbers, like icv_iar_read, check
against 1020 and not against num_irq.

Fix the checks by using GICV3_MAXIRQ (1020) instead of the number of
implemented IRQs.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
Message-id: 20210702233701.3369-1-ricarkol@google.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 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 3e0641aff97..a032d505f53 100644
--- a/hw/intc/arm_gicv3_cpuif.c
+++ b/hw/intc/arm_gicv3_cpuif.c
@@ -1227,7 +1227,7 @@ static void icv_dir_write(CPUARMState *env, const 
ARMCPRegInfo *ri,
 
     trace_gicv3_icv_dir_write(gicv3_redist_affid(cs), value);
 
-    if (irq >= cs->gic->num_irq) {
+    if (irq >= GICV3_MAXIRQ) {
         /* Also catches special interrupt numbers and LPIs */
         return;
     }
@@ -1262,7 +1262,7 @@ static void icv_eoir_write(CPUARMState *env, const 
ARMCPRegInfo *ri,
     trace_gicv3_icv_eoir_write(ri->crm == 8 ? 0 : 1,
                                gicv3_redist_affid(cs), value);
 
-    if (irq >= cs->gic->num_irq) {
+    if (irq >= GICV3_MAXIRQ) {
         /* Also catches special interrupt numbers and LPIs */
         return;
     }
-- 
2.20.1