If we aren't going to create any RPUs, then don't create the
rpu-cluster unit. This allows us to add an assertion to the
cluster object that it contains at least one CPU, which helps
to avoid bugs in creating clusters and putting CPUs in them.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190121184314.14311-1-peter.maydell@linaro.org
---
 hw/arm/xlnx-zynqmp.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/arm/xlnx-zynqmp.c b/hw/arm/xlnx-zynqmp.c
index c67ac2e64ac..70cbe6bd475 100644
--- a/hw/arm/xlnx-zynqmp.c
+++ b/hw/arm/xlnx-zynqmp.c
@@ -178,6 +178,11 @@ static void xlnx_zynqmp_create_rpu(XlnxZynqMPState *s, const char *boot_cpu,
     int i;
     int num_rpus = MIN(smp_cpus - XLNX_ZYNQMP_NUM_APU_CPUS, XLNX_ZYNQMP_NUM_RPU_CPUS);
 
+    if (num_rpus <= 0) {
+        /* Don't create rpu-cluster object if there's nothing to put in it */
+        return;
+    }
+
     object_initialize_child(OBJECT(s), "rpu-cluster", &s->rpu_cluster,
                             sizeof(s->rpu_cluster), TYPE_CPU_CLUSTER,
                             &error_abort, NULL);
-- 
2.20.1