hw/pci-host/gpex: Improve INTX to gsi routing error checking

We exposed gpex_set_irq_num() for machines to set the INTx to
GSI routing. However if the machine forgets to call that
function we currently do not check the association was properly
done. Let's initialize gsi values to -1 and if this value is
found in gpex_route_intx_pin_to_irq, set the routing mode as
disabled.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Message-id: 1508776211-22175-1-git-send-email-eric.auger@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/hw/pci-host/gpex.c b/hw/pci-host/gpex.c
index 4090793cf0aae022513783870863dee72571a7b3..edf305b1fda2aa2d17b2679d2b1c2e007c6d451b 100644 (file)
--- a/hw/pci-host/gpex.c
+++ b/hw/pci-host/gpex.c
@@ -57,9 +57,14 @@ static PCIINTxRoute gpex_route_intx_pin_to_irq(void *opaque, int pin)
 {
     PCIINTxRoute route;
     GPEXHost *s = opaque;
+    int gsi = s->irq_num[pin];
 
-    route.mode = PCI_INTX_ENABLED;
-    route.irq = s->irq_num[pin];
+    route.irq = gsi;
+    if (gsi < 0) {
+        route.mode = PCI_INTX_DISABLED;
+    } else {
+        route.mode = PCI_INTX_ENABLED;
+    }
 
     return route;
 }
@@ -81,6 +86,7 @@ static void gpex_host_realize(DeviceState *dev, Error **errp)
     sysbus_init_mmio(sbd, &s->io_ioport);
     for (i = 0; i < GPEX_NUM_IRQS; i++) {
         sysbus_init_irq(sbd, &s->irq[i]);
+        s->irq_num[i] = -1;
     }
 
     pci->bus = pci_register_bus(dev, "pcie.0", gpex_set_irq,