[PATCH v4 12/17] hw/arm: virt: cleanly fail on attempt to use the platform vGIC together with ITS

[Mohamed Mediouni]

Windows Hypervisor Platform's vGIC doesn't support ITS.
Deal with this by reporting to the user and not creating the ITS device.

Signed-off-by: Mohamed Mediouni <moha...@unpredictable.fr>
---
 hw/arm/virt.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 98a1c74c42..0039f6a12b 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -741,6 +741,16 @@ static void create_its(VirtMachineState *vms)
         return;
     }
 
+    if (whpx_enabled() && vms->tcg_its) {
+        /*
+         * Signal to the user when ITS is neither supported by the host
+         * nor emulated by the machine.
+         */
+        info_report("ITS not supported on WHPX.");
+        info_report("To support MSIs, use its=off to enable GICv3 + GICv2m.");
+        return;
+    }
+
     dev = qdev_new(its_class_name());
 
     object_property_set_link(OBJECT(dev), "parent-gicv3", OBJECT(vms->gic),
-- 
2.39.5 (Apple Git-154)