hw/arm/fsl-imx: Fix introspection problem with fsl-imx6 and fsl-imx7

QEMU currently exits unexpectedly when trying to introspect the fsl-imx6
and fsl-imx7 devices on systems with many SMP CPUs:

$ echo "{'execute':'qmp_capabilities'}"\
       "{'execute':'device-list-properties',"\
       " 'arguments':{'typename':'fsl,imx6'}}" \
       | arm-softmmu/qemu-system-arm -M virt,accel=qtest -qmp stdio -smp 8
{"QMP": {"version": {"qemu": {"micro": 91, "minor": 11, "major": 2},
 "package": "build-all"}, "capabilities": []}}
{"return": {}}
fsl,imx6: Only 4 CPUs are supported (8 requested)

And:

$ echo "{'execute':'qmp_capabilities'}"\
       "{'execute':'device-list-properties',"\
       " 'arguments':{'typename':'fsl,imx7'}}" \
       | arm-softmmu/qemu-system-arm -M raspi2,accel=qtest -qmp stdio
{"QMP": {"version": {"qemu": {"micro": 91, "minor": 11, "major": 2},
 "package": "build-all"}, "capabilities": []}}
{"return": {}}
fsl,imx7: Only 2 CPUs are supported (4 requested)

This happens because these devices are doing an exit() from their
instance_init function - which should never be done since instance_init
can be called at any time for device introspection! Fix it by moving
the deadly check into the realize() function instead.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-id: 1522908551-14885-1-git-send-email-thuth@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 14 insertions, 13 deletions

diff --git a/hw/arm/fsl-imx6.c b/hw/arm/fsl-imx6.c
index b6ac72de27..9dfbc9a8c4 100644
--- a/hw/arm/fsl-imx6.c
+++ b/hw/arm/fsl-imx6.c
@@ -37,13 +37,7 @@ static void fsl_imx6_init(Object *obj)
     char name[NAME_SIZE];
     int i;
 
-    if (smp_cpus > FSL_IMX6_NUM_CPUS) {
-        error_report("%s: Only %d CPUs are supported (%d requested)",
-                     TYPE_FSL_IMX6, FSL_IMX6_NUM_CPUS, smp_cpus);
-        exit(1);
-    }
-
-    for (i = 0; i < smp_cpus; i++) {
+    for (i = 0; i < MIN(smp_cpus, FSL_IMX6_NUM_CPUS); i++) {
         object_initialize(&s->cpu[i], sizeof(s->cpu[i]),
                           "cortex-a9-" TYPE_ARM_CPU);
         snprintf(name, NAME_SIZE, "cpu%d", i);
@@ -119,6 +113,12 @@ static void fsl_imx6_realize(DeviceState *dev, Error **errp)
     uint16_t i;
     Error *err = NULL;
 
+    if (smp_cpus > FSL_IMX6_NUM_CPUS) {
+        error_setg(errp, "%s: Only %d CPUs are supported (%d requested)",
+                   TYPE_FSL_IMX6, FSL_IMX6_NUM_CPUS, smp_cpus);
+        return;
+    }
+
     for (i = 0; i < smp_cpus; i++) {
 
         /* On uniprocessor, the CBAR is set to 0 */
diff --git a/hw/arm/fsl-imx7.c b/hw/arm/fsl-imx7.c
index 26ef36c79a..390b4310e6 100644
--- a/hw/arm/fsl-imx7.c
+++ b/hw/arm/fsl-imx7.c
@@ -35,13 +35,8 @@ static void fsl_imx7_init(Object *obj)
     char name[NAME_SIZE];
     int i;
 
-    if (smp_cpus > FSL_IMX7_NUM_CPUS) {
-        error_report("%s: Only %d CPUs are supported (%d requested)",
-                     TYPE_FSL_IMX7, FSL_IMX7_NUM_CPUS, smp_cpus);
-        exit(1);
-    }
 
-    for (i = 0; i < smp_cpus; i++) {
+    for (i = 0; i < MIN(smp_cpus, FSL_IMX7_NUM_CPUS); i++) {
         object_initialize(&s->cpu[i], sizeof(s->cpu[i]),
                           ARM_CPU_TYPE_NAME("cortex-a7"));
         snprintf(name, NAME_SIZE, "cpu%d", i);
@@ -197,6 +192,12 @@ static void fsl_imx7_realize(DeviceState *dev, Error **errp)
     qemu_irq irq;
     char name[NAME_SIZE];
 
+    if (smp_cpus > FSL_IMX7_NUM_CPUS) {
+        error_setg(errp, "%s: Only %d CPUs are supported (%d requested)",
+                   TYPE_FSL_IMX7, FSL_IMX7_NUM_CPUS, smp_cpus);
+        return;
+    }
+
     for (i = 0; i < smp_cpus; i++) {
         o = OBJECT(&s->cpu[i]);