[Qemu-devel] [PATCH RFC 1/3] qdev: add device creation priority flag

[Marcel Apfelbaum <marcel@redhat.com>]

Some devices need to be created before others. Add a flag
to DeviceClass and the means to query it.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
---
 include/hw/qdev-core.h | 13 +++++++++++++
 include/monitor/qdev.h |  1 +
 qdev-monitor.c         | 19 +++++++++++++++++++
 3 files changed, 33 insertions(+)

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 1ce02b2..f885d6c 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -29,6 +29,13 @@ typedef enum DeviceCategory {
     DEVICE_CATEGORY_MAX
 } DeviceCategory;
 
+
+typedef enum DeviceCreationPriority {
+    DEVICE_PRIO_NORMAL,
+    DEVICE_PRIO_BRIDGE,
+    DEVICE_PRIO_HOSTBRIDGE
+} DeviceCreationPriority;
+
 typedef int (*qdev_initfn)(DeviceState *dev);
 typedef int (*qdev_event)(DeviceState *dev);
 typedef void (*qdev_resetfn)(DeviceState *dev);
@@ -139,6 +146,12 @@ typedef struct DeviceClass {
     qdev_initfn init; /* TODO remove, once users are converted to realize */
     qdev_event exit; /* TODO remove, once users are converted to unrealize */
     const char *bus_type;
+
+    /*
+     * Some devices need to be created before others. Devices with higher
+     * priority will be created first.
+     */
+    DeviceCreationPriority creation_priority;
 } DeviceClass;
 
 typedef struct NamedGPIOList NamedGPIOList;
diff --git a/include/monitor/qdev.h b/include/monitor/qdev.h
index c4b8a05..7f35ee5 100644
--- a/include/monitor/qdev.h
+++ b/include/monitor/qdev.h
@@ -12,5 +12,6 @@ void qmp_device_add(QDict *qdict, QObject **ret_data, Error **errp);
 
 int qdev_device_help(QemuOpts *opts);
 DeviceState *qdev_device_add(QemuOpts *opts, Error **errp);
+int qdev_device_get_priority(QemuOpts *opts, Error **errp);
 
 #endif
diff --git a/qdev-monitor.c b/qdev-monitor.c
index e19617f..0edba77 100644
--- a/qdev-monitor.c
+++ b/qdev-monitor.c
@@ -626,6 +626,25 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
     return dev;
 }
 
+int qdev_device_get_priority(QemuOpts *opts, Error **errp)
+{
+    DeviceClass *dc;
+    const char *driver;
+
+    driver = qemu_opt_get(opts, "driver");
+    if (!driver) {
+        error_setg(errp, QERR_MISSING_PARAMETER, "driver");
+        return -1;
+    }
+
+    /* find driver */
+    dc = qdev_get_device_class(&driver, errp);
+    if (!dc) {
+        return -1;
+    }
+
+    return dc->creation_priority;
+}
 
 #define qdev_printf(fmt, ...) monitor_printf(mon, "%*s" fmt, indent, "", ## __VA_ARGS__)
 static void qbus_print(Monitor *mon, BusState *bus, int indent);
-- 
2.4.3