Re: [PATCH v5 02/13] hw/core/qdev: add trace events to help with resettable transition

[Philippe Mathieu-Daudé]

On 10/18/19 5:06 PM, Damien Hedde wrote:
> Adds trace events to reset procedure and when updating the parent
> bus of a device.
>
> Signed-off-by: Damien Hedde <address@hidden>
> ---
>   hw/core/qdev.c       | 27 ++++++++++++++++++++++++---
>   hw/core/trace-events |  9 +++++++++
>   2 files changed, 33 insertions(+), 3 deletions(-)
>
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index 60be2f2fef..f230063189 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 +99,9 @@ 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, dev->parent_bus, bus);

Nitpicking, if you respin, can you add object_get_typename(OBJECT(dev))) 
and object_get_typename(OBJECT(bus)))?

With/without it:
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> +        /*
> +         * 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().
>            */
> @@ -272,6 +275,18 @@ 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);
> @@ -282,6 +297,7 @@ 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);
>       }
> @@ -290,7 +306,9 @@ 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)
> @@ -300,7 +318,9 @@ 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)
> @@ -1108,6 +1128,7 @@ 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..1a669be0ea 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, void *oldp, void *newp) "obj=%p old_parent=%p 
> new_parent=%p"