machine: Provide a function to check the dynamic sysbus allowlist

Provide a new function dynamic_sysbus_dev_allowed() which checks the
per-machine list of permitted dynamic sysbus devices and returns a
boolean result indicating whether the device is allowed.  We can use
this in the implementation of validate_sysbus_device(), but we will
also need it so that machine hotplug callbacks can validate devices
rather than assuming that any sysbus device might be hotpluggable
into the platform bus.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-id: 20210325153310.9131-3-peter.maydell@linaro.org

1 files changed, 16 insertions, 5 deletions

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 9935c6d..8d97094 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -529,20 +529,31 @@ void machine_class_allow_dynamic_sysbus_dev(MachineClass *mc, const char *type)
     QAPI_LIST_PREPEND(mc->allowed_dynamic_sysbus_devices, g_strdup(type));
 }
 
-static void validate_sysbus_device(SysBusDevice *sbdev, void *opaque)
+bool device_is_dynamic_sysbus(MachineClass *mc, DeviceState *dev)
 {
-    MachineState *machine = opaque;
-    MachineClass *mc = MACHINE_GET_CLASS(machine);
     bool allowed = false;
     strList *wl;
+    Object *obj = OBJECT(dev);
+
+    if (!object_dynamic_cast(obj, TYPE_SYS_BUS_DEVICE)) {
+        return false;
+    }
 
     for (wl = mc->allowed_dynamic_sysbus_devices;
          !allowed && wl;
          wl = wl->next) {
-        allowed |= !!object_dynamic_cast(OBJECT(sbdev), wl->value);
+        allowed |= !!object_dynamic_cast(obj, wl->value);
     }
 
-    if (!allowed) {
+    return allowed;
+}
+
+static void validate_sysbus_device(SysBusDevice *sbdev, void *opaque)
+{
+    MachineState *machine = opaque;
+    MachineClass *mc = MACHINE_GET_CLASS(machine);
+
+    if (!device_is_dynamic_sysbus(mc, DEVICE(sbdev))) {
         error_report("Option '-device %s' cannot be handled by this machine",
                      object_class_get_name(object_get_class(OBJECT(sbdev))));
         exit(1);