This commit make use of the resettable API to reset the device being hotplugged when it is realized. Also it ensures it is put in a reset state coherent with the parent it is plugged into.
Note that there is a difference in the reset. Instead of resetting only the hotplugged device, we reset also its subtree (switch to resettable API). This is not expected to be a problem because sub-buses are just realized too. If a hotplugged device has any sub-buses it is logical to reset them too at this point. The recently added should_be_hidden and PCI's partially_hotplugged mechanisms do not interfere with realize operation: + In the should_be_hidden use case, device creation is delayed. + The partially_hotplugged mechanism prevents a device to be unplugged and unrealized from qdev POV and unrealized. Signed-off-by: Damien Hedde <damien.he...@greensocs.com> Reviewed-by: Richard Henderson <richard.hender...@linaro.org> --- v7 update: inline resettable_state_clear() v6 update: clear the reset state before doing any reset. Although it is apparently highly improbable that a device be realized again after being unrealized. See here for a discussion about this point and the partially_hotplugged/shoud_be_hidden cases. https://lists.nongnu.org/archive/html/qemu-devel/2019-11/msg04897.html --- include/hw/resettable.h | 11 +++++++++++ hw/core/qdev.c | 15 ++++++++++++++- 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/include/hw/resettable.h b/include/hw/resettable.h index 3c87ab86c7..3f90da5b5b 100644 --- a/include/hw/resettable.h +++ b/include/hw/resettable.h @@ -153,6 +153,17 @@ struct ResettableState { bool exit_phase_in_progress; }; +/** + * resettable_state_clear: + * Clear the state. It puts the state to the initial (zeroed) state required + * to reuse an object. Typically used in realize step of base classes + * implementing the interface. + */ +static inline void resettable_state_clear(ResettableState *state) +{ + memset(state, 0, sizeof(ResettableState)); +} + /** * resettable_reset: * Trigger a reset on an object @obj of type @type. @obj must implement diff --git a/hw/core/qdev.c b/hw/core/qdev.c index 310b87e25a..5fac4cd8fc 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -937,6 +937,12 @@ static void device_set_realized(Object *obj, bool value, Error **errp) } } + /* + * Clear the reset state, in case the object was previously unrealized + * with a dirty state. + */ + resettable_state_clear(&dev->reset); + QLIST_FOREACH(bus, &dev->child_bus, sibling) { object_property_set_bool(OBJECT(bus), true, "realized", &local_err); @@ -945,7 +951,14 @@ static void device_set_realized(Object *obj, bool value, Error **errp) } } if (dev->hotplugged) { - device_legacy_reset(dev); + /* + * Reset the device, as well as its subtree which, at this point, + * should be realized too. + */ + resettable_assert_reset(OBJECT(dev), RESET_TYPE_COLD); + resettable_change_parent(OBJECT(dev), OBJECT(dev->parent_bus), + NULL); + resettable_release_reset(OBJECT(dev), RESET_TYPE_COLD); } dev->pending_deleted_event = false; -- 2.24.1
