Re: [PATCH v7 02/11] hw/core/qdev: add trace events to help with resettable transition

[Philippe Mathieu-Daudé]

On 1/15/20 1:36 PM, Damien Hedde wrote:

Adds trace events to reset procedure and when updating the parent
bus of a device.

Signed-off-by: Damien Hedde <damien.he...@greensocs.com>
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
Reviewed-by: Cornelia Huck <coh...@redhat.com>

Tested-by: Philippe Mathieu-Daudé <phi...@redhat.com>

---
  hw/core/qdev.c       | 29 ++++++++++++++++++++++++++---
  hw/core/trace-events |  9 +++++++++
  2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 8c0c8284c8..5cb03136b5 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -38,6 +38,7 @@
  #include "hw/boards.h"
  #include "hw/sysbus.h"
  #include "migration/vmstate.h"
+#include "trace.h"

bool qdev_hotplug = false;

  static bool qdev_hot_added = false;
@@ -98,7 +99,11 @@ void qdev_set_parent_bus(DeviceState *dev, BusState *bus)
      bool replugging = dev->parent_bus != NULL;

if (replugging) {

-        /* Keep a reference to the device while it's not plugged into
+        trace_qdev_update_parent_bus(dev, object_get_typename(OBJECT(dev)),
+            dev->parent_bus, object_get_typename(OBJECT(dev->parent_bus)),
+            OBJECT(bus), object_get_typename(OBJECT(bus)));
+        /*
+         * Keep a reference to the device while it's not plugged into
           * any bus, to avoid it potentially evaporating when it is
           * dereffed in bus_remove_child().
           */
@@ -296,6 +301,18 @@ HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev)
      return hotplug_ctrl;
  }

+static int qdev_prereset(DeviceState *dev, void *opaque)

+{
+    trace_qdev_reset_tree(dev, object_get_typename(OBJECT(dev)));
+    return 0;
+}
+
+static int qbus_prereset(BusState *bus, void *opaque)
+{
+    trace_qbus_reset_tree(bus, object_get_typename(OBJECT(bus)));
+    return 0;
+}
+
  static int qdev_reset_one(DeviceState *dev, void *opaque)
  {
      device_legacy_reset(dev);
@@ -306,6 +323,7 @@ static int qdev_reset_one(DeviceState *dev, void *opaque)
  static int qbus_reset_one(BusState *bus, void *opaque)
  {
      BusClass *bc = BUS_GET_CLASS(bus);
+    trace_qbus_reset(bus, object_get_typename(OBJECT(bus)));
      if (bc->reset) {
          bc->reset(bus);
      }
@@ -314,7 +332,9 @@ static int qbus_reset_one(BusState *bus, void *opaque)

void qdev_reset_all(DeviceState *dev)

  {
-    qdev_walk_children(dev, NULL, NULL, qdev_reset_one, qbus_reset_one, NULL);
+    trace_qdev_reset_all(dev, object_get_typename(OBJECT(dev)));
+    qdev_walk_children(dev, qdev_prereset, qbus_prereset,
+                       qdev_reset_one, qbus_reset_one, NULL);
  }

void qdev_reset_all_fn(void *opaque)

@@ -324,7 +344,9 @@ void qdev_reset_all_fn(void *opaque)

void qbus_reset_all(BusState *bus)

  {
-    qbus_walk_children(bus, NULL, NULL, qdev_reset_one, qbus_reset_one, NULL);
+    trace_qbus_reset_all(bus, object_get_typename(OBJECT(bus)));
+    qbus_walk_children(bus, qdev_prereset, qbus_prereset,
+                       qdev_reset_one, qbus_reset_one, NULL);
  }

void qbus_reset_all_fn(void *opaque)

@@ -1131,6 +1153,7 @@ void device_legacy_reset(DeviceState *dev)
  {
      DeviceClass *klass = DEVICE_GET_CLASS(dev);

+ trace_qdev_reset(dev, object_get_typename(OBJECT(dev)));

      if (klass->reset) {
          klass->reset(dev);
      }
diff --git a/hw/core/trace-events b/hw/core/trace-events
index fe47a9c8cb..a375aa88a4 100644
--- a/hw/core/trace-events
+++ b/hw/core/trace-events
@@ -1,2 +1,11 @@
  # loader.c
  loader_write_rom(const char *name, uint64_t gpa, uint64_t size, bool isrom) "%s: 
@0x%"PRIx64" size=0x%"PRIx64" ROM=%d"
+
+# qdev.c
+qdev_reset(void *obj, const char *objtype) "obj=%p(%s)"
+qdev_reset_all(void *obj, const char *objtype) "obj=%p(%s)"
+qdev_reset_tree(void *obj, const char *objtype) "obj=%p(%s)"
+qbus_reset(void *obj, const char *objtype) "obj=%p(%s)"
+qbus_reset_all(void *obj, const char *objtype) "obj=%p(%s)"
+qbus_reset_tree(void *obj, const char *objtype) "obj=%p(%s)"
+qdev_update_parent_bus(void *obj, const char *objtype, void *oldp, const char *oldptype, 
void *newp, const char *newptype) "obj=%p(%s) old_parent=%p(%s) 
new_parent=%p(%s)"