sysbus: add creation function that may fail

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

hw/sysbus.c

@@ -173,6 +173,37 @@ DeviceState *sysbus_create_varargs(const char *name,
     return dev;
 }
 
+DeviceState *sysbus_try_create_varargs(const char *name,
+                                       target_phys_addr_t addr, ...)
+{
+    DeviceState *dev;
+    SysBusDevice *s;
+    va_list va;
+    qemu_irq irq;
+    int n;
+
+    dev = qdev_try_create(NULL, name);
+    if (!dev) {
+        return NULL;
+    }
+    s = sysbus_from_qdev(dev);
+    qdev_init_nofail(dev);
+    if (addr != (target_phys_addr_t)-1) {
+        sysbus_mmio_map(s, 0, addr);
+    }
+    va_start(va, addr);
+    n = 0;
+    while (1) {
+        irq = va_arg(va, qemu_irq);
+        if (!irq) {
+            break;
+        }
+        sysbus_connect_irq(s, n, irq);
+        n++;
+    }
+    return dev;
+}
+
 static void sysbus_dev_print(Monitor *mon, DeviceState *dev, int indent)
 {
     SysBusDevice *s = sysbus_from_qdev(dev);

hw/sysbus.h

@@ -57,6 +57,8 @@ void sysbus_mmio_map(SysBusDevice *dev, int n, target_phys_addr_t addr);
 /* Legacy helper function for creating devices.  */
 DeviceState *sysbus_create_varargs(const char *name,
                                  target_phys_addr_t addr, ...);
+DeviceState *sysbus_try_create_varargs(const char *name,
+                                       target_phys_addr_t addr, ...);
 static inline DeviceState *sysbus_create_simple(const char *name,
                                               target_phys_addr_t addr,
                                               qemu_irq irq)
@@ -64,4 +66,11 @@ static inline DeviceState *sysbus_create_simple(const char *name,
     return sysbus_create_varargs(name, addr, irq, NULL);
 }
 
+static inline DeviceState *sysbus_try_create_simple(const char *name,
+                                                    target_phys_addr_t addr,
+                                                    qemu_irq irq)
+{
+    return sysbus_try_create_varargs(name, addr, irq, NULL);
+}
+
 #endif /* !HW_SYSBUS_H */