| Message ID | 20250128142152.9889-5-philmd@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | accel: Only include qdev-realized vCPUs in global &cpus_queue | expand |
On 1/28/25 06:21, Philippe Mathieu-Daudé wrote: > We are trying to understand what means "a qdev is realized". > One explanation was "the device is guest visible"; however > many devices are realized before being mapped, thus are not > "guest visible". Some devices map / wire their IRQs before > being realized (such ISA devices). There is a need for devices > to be "automatically" mapped/wired (see [2]) such CLI-created > devices, but this apply generically to dynamic machines. > > Currently the device creation steps are expected to roughly be: > > (external use) (QDev core) (Device Impl) > ~~~~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~~~~ > > INIT enter > -----> > +----------------------+ > | Allocate state | > +----------------------+ > -----> > +---------------------+ > | INIT children | > | | > | Alias children properties > | | > | Expose properties | > INIT exit +---------------------+ > <----------------------------------- > +----------------+ > | set properties | > | | > | set ClkIn | > +----------------+ REALIZE enter > ----------------------------------> > +----------------------+ > | Use config properties| > | | > | Realize children | > | | > | Init GPIOs/IRQs | > | | > | Init MemoryRegions | > +----------------------+ > REALIZE exit > <----------------------------------- ---- "realized" / "guest visible" > +-----------------+ > | Explicit wiring:| > | IRQs | > | I/O / Mem | > | ClkOut | > +-----------------+ RESET enter > ---------------------------------> > +----------------------+ > | Reset default values | > +----------------------+ > > But as mentioned, various devices "wire" parts before they exit > the "realize" step. > In order to clarify, I'm trying to enforce what can be done > *before* and *after* realization. > > *after* a device is expected to be stable (no more configurable) > and fully usable. > > To be able to use internal/auto wiring (such ISA devices) and > keep the current external/explicit wiring, I propose to add an > extra "internal wiring" step, happening after the REALIZE step > as: > > (external use) (QDev core) (Device Impl) > ~~~~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~~~~ > > INIT enter > -----> > +----------------------+ > | Allocate state | > +----------------------+ > -----> > +---------------------+ > | INIT children | > | | > | Alias children properties > | | > | Expose properties | > INIT exit +---------------------+ > <----------------------------------- > +----------------+ > | set properties | > | | > | set ClkIn | > +----------------+ REALIZE enter > ----------------------------------> > +----------------------+ > | Use config properties| > | | > | Realize children | > | | > | Init GPIOs/IRQs | > | | > | Init MemoryRegions | > +----------------------+ > REALIZE exit <--- > +----------------------+ > | Internal auto wiring | > | IRQs | (i.e. ISA bus) > | I/O / Mem | > | ClkOut | > +----------------------+ > <--- ---- "realized" > +-----------------+ > | External wiring:| > | IRQs | > | I/O / Mem | > | ClkOut | > +-----------------+ RESET enter ---- "guest visible" > ---------------------------------> > +----------------------+ > | Reset default values | > +----------------------+ > > The "realized" point is not changed. "guest visible" concept only > occurs *after* wiring, just before the reset phase. > > This change introduces the DeviceClass::wire handler within qdev > core realization code. > > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> > --- > include/hw/qdev-core.h | 7 +++++++ > hw/core/qdev.c | 20 +++++++++++++++++++- > 2 files changed, 26 insertions(+), 1 deletion(-) > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h > index 530f3da7021..021bb7afdc0 100644 > --- a/include/hw/qdev-core.h > +++ b/include/hw/qdev-core.h > @@ -102,7 +102,12 @@ typedef int (*DeviceSyncConfig)(DeviceState *dev, Error **errp); > * @props: Properties accessing state fields. > * @realize: Callback function invoked when the #DeviceState:realized > * property is changed to %true. > + * @wire: Callback function called after @realize to connect IRQs, > + * clocks and map memories. Can not fail. > + * @unwire: Callback function to undo @wire. Called before @unrealize. > + * Can not fail. > * @unrealize: Callback function invoked when the #DeviceState:realized > + * property is changed to %false. Can not fail. > * property is changed to %false. > * @sync_config: Callback function invoked when QMP command device-sync-config > * is called. Should synchronize device configuration from host to guest part > @@ -171,6 +176,8 @@ struct DeviceClass { > */ > DeviceReset legacy_reset; > DeviceRealize realize; > + void (*wire)(DeviceState *dev); > + void (*unwire)(DeviceState *dev); > DeviceUnrealize unrealize; > DeviceSyncConfig sync_config; > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c > index 82bbdcb654e..38449255365 100644 > --- a/hw/core/qdev.c > +++ b/hw/core/qdev.c > @@ -554,6 +554,15 @@ static void device_set_realized(Object *obj, bool value, Error **errp) > } > } > > + if (dc->wire) { > + if (!dc->unwire) { > + warn_report_once("wire() without unwire() for type '%s'", > + object_get_typename(OBJECT(dev))); > + } > + dc->wire(dev); > + } > + > + /* At this point the device is "guest visible". */ > qatomic_store_release(&dev->realized, value); > > } else if (!value && dev->realized) { > @@ -573,6 +582,15 @@ static void device_set_realized(Object *obj, bool value, Error **errp) > */ > smp_wmb(); > > + if (dc->unwire) { > + if (!dc->wire) { > + error_report("disconnect() without connect() for type '%s'", > + object_get_typename(OBJECT(dev))); > + abort(); > + } > + dc->unwire(dev); > + } Mismatched error messages (wire vs connect). But, really, just check both directions properly at startup. There's probably lots of places where devices are never unrealized. Otherwise, this seems sane, having a kind of post_init on the realize path, running after all superclass realization is done. r~
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h index 530f3da7021..021bb7afdc0 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -102,7 +102,12 @@ typedef int (*DeviceSyncConfig)(DeviceState *dev, Error **errp); * @props: Properties accessing state fields. * @realize: Callback function invoked when the #DeviceState:realized * property is changed to %true. + * @wire: Callback function called after @realize to connect IRQs, + * clocks and map memories. Can not fail. + * @unwire: Callback function to undo @wire. Called before @unrealize. + * Can not fail. * @unrealize: Callback function invoked when the #DeviceState:realized + * property is changed to %false. Can not fail. * property is changed to %false. * @sync_config: Callback function invoked when QMP command device-sync-config * is called. Should synchronize device configuration from host to guest part @@ -171,6 +176,8 @@ struct DeviceClass { */ DeviceReset legacy_reset; DeviceRealize realize; + void (*wire)(DeviceState *dev); + void (*unwire)(DeviceState *dev); DeviceUnrealize unrealize; DeviceSyncConfig sync_config; diff --git a/hw/core/qdev.c b/hw/core/qdev.c index 82bbdcb654e..38449255365 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -554,6 +554,15 @@ static void device_set_realized(Object *obj, bool value, Error **errp) } } + if (dc->wire) { + if (!dc->unwire) { + warn_report_once("wire() without unwire() for type '%s'", + object_get_typename(OBJECT(dev))); + } + dc->wire(dev); + } + + /* At this point the device is "guest visible". */ qatomic_store_release(&dev->realized, value); } else if (!value && dev->realized) { @@ -573,6 +582,15 @@ static void device_set_realized(Object *obj, bool value, Error **errp) */ smp_wmb(); + if (dc->unwire) { + if (!dc->wire) { + error_report("disconnect() without connect() for type '%s'", + object_get_typename(OBJECT(dev))); + abort(); + } + dc->unwire(dev); + } + QLIST_FOREACH(bus, &dev->child_bus, sibling) { qbus_unrealize(bus); } @@ -585,8 +603,8 @@ static void device_set_realized(Object *obj, bool value, Error **errp) dev->pending_deleted_event = true; DEVICE_LISTENER_CALL(unrealize, Reverse, dev); } - assert(local_err == NULL); + return; child_realize_fail:
We are trying to understand what means "a qdev is realized". One explanation was "the device is guest visible"; however many devices are realized before being mapped, thus are not "guest visible". Some devices map / wire their IRQs before being realized (such ISA devices). There is a need for devices to be "automatically" mapped/wired (see [2]) such CLI-created devices, but this apply generically to dynamic machines. Currently the device creation steps are expected to roughly be: (external use) (QDev core) (Device Impl) ~~~~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~~~~ INIT enter -----> +----------------------+ | Allocate state | +----------------------+ -----> +---------------------+ | INIT children | | | | Alias children properties | | | Expose properties | INIT exit +---------------------+ <----------------------------------- +----------------+ | set properties | | | | set ClkIn | +----------------+ REALIZE enter ----------------------------------> +----------------------+ | Use config properties| | | | Realize children | | | | Init GPIOs/IRQs | | | | Init MemoryRegions | +----------------------+ REALIZE exit <----------------------------------- ---- "realized" / "guest visible" +-----------------+ | Explicit wiring:| | IRQs | | I/O / Mem | | ClkOut | +-----------------+ RESET enter ---------------------------------> +----------------------+ | Reset default values | +----------------------+ But as mentioned, various devices "wire" parts before they exit the "realize" step. In order to clarify, I'm trying to enforce what can be done *before* and *after* realization. *after* a device is expected to be stable (no more configurable) and fully usable. To be able to use internal/auto wiring (such ISA devices) and keep the current external/explicit wiring, I propose to add an extra "internal wiring" step, happening after the REALIZE step as: (external use) (QDev core) (Device Impl) ~~~~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~~~~ INIT enter -----> +----------------------+ | Allocate state | +----------------------+ -----> +---------------------+ | INIT children | | | | Alias children properties | | | Expose properties | INIT exit +---------------------+ <----------------------------------- +----------------+ | set properties | | | | set ClkIn | +----------------+ REALIZE enter ----------------------------------> +----------------------+ | Use config properties| | | | Realize children | | | | Init GPIOs/IRQs | | | | Init MemoryRegions | +----------------------+ REALIZE exit <--- +----------------------+ | Internal auto wiring | | IRQs | (i.e. ISA bus) | I/O / Mem | | ClkOut | +----------------------+ <--- ---- "realized" +-----------------+ | External wiring:| | IRQs | | I/O / Mem | | ClkOut | +-----------------+ RESET enter ---- "guest visible" ---------------------------------> +----------------------+ | Reset default values | +----------------------+ The "realized" point is not changed. "guest visible" concept only occurs *after* wiring, just before the reset phase. This change introduces the DeviceClass::wire handler within qdev core realization code. Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> --- include/hw/qdev-core.h | 7 +++++++ hw/core/qdev.c | 20 +++++++++++++++++++- 2 files changed, 26 insertions(+), 1 deletion(-)