docs/devel/reset.rst

18 ----------------
43   have some non-deterministic state they want to reinitialize to a different
45   must not reinitialize on a snapshot-load reset.
49   its devices during wake-up (from the ``MachineClass::wakeup()`` method), this
51   type to differentiate the reset requested during machine wake-up from other
52   reset requests. For example, RAM content must not be lost during wake-up, and
53   memory devices like virtio-mem that provide additional RAM must not reset
54   such state during wake-ups, but might do so during cold resets. However, this
55   reset type should not be used for wake-up detection, as not every machine
56   type issues a device reset request during wake-up.
78 maintaining a count of in-progress resets; it is crucial to call
88 non-resettable object and it will trigger a run time assert error. Since most
94 - ``device_cold_reset()``
95 - ``bus_cold_reset()``
101 Device and bus functions co-exist because there can be semantic differences
109 Multi-phase mechanism
110 ---------------------
114 The resettable interface uses a multi-phase system to relieve objects and
125    local state of the object; it must not do anything that has a side-effect
146 DMA capable devices are expected to cancel all outstanding DMA operations
148 the 'exit' phase and this sequencing makes sure no outstanding DMA request
153 -------------------------------------
182         if (myclass->parent_phases.enter) {
183             myclass->parent_phases.enter(obj, type);
186         mydev->var = 0;
194         if (myclass->parent_phases.hold) {
195             myclass->parent_phases.hold(obj, type);
198         qemu_set_irq(mydev->irq, 1);
206         if (myclass->parent_phases.exit) {
207             myclass->parent_phases.exit(obj, type);
210         qemu_set_irq(mydev->irq, 0);
227                                            &myclass->parent_phases);
236                                        &myclass->parent_phases);
270 ----------------------------
317 do so: the function is a no-op as long as old and new parent are NULL or not
329 ----------------------------
349    the three-phase mechanism listed above. It resets all objects
363    rather than from ``TYPE_SYS_BUS_DEVICE`` or some other plugs-into-a-bus