Ping, Am 26.11.2012 01:12, schrieb Andreas Färber: > Hello Anthony and Paolo, > > As announced at KVM Forum, I have been preparing a new approach to > incrementally > get us Anthony's QOM realizefn concept. A previous attempt by Paolo and me had > been turned down for making this available at Object-level and over questions > whether BlockDriverState may need its own three-stage realization model. > > So here's an all-new patchset doing it at DeviceState-level only, adapting the > signature to void realize(DeviceState *, Error **). > CPUState is on a good way to get derived from DeviceState, so in the future > will benefit from this approach as well. > > I've picked ISADevice as an example to showcase what semantic effects the > switch to QOM realizefn has (in the hopes the number of devices would be > small): > As requested by Anthony for QOM CPUState reset and as seen with virtual > methods > in object-oriented programming languages, it becomes the derived method's > responsibility to decide when and whether to call the parent class' method. In > lack of real vtables this requires to save the parent's method in case we want > to call it; classes and matching macros may need to be added for that. > Another point to note is that we should carefully distinguish what goes into > the qdev initfn / QOM realizefn and what can already go into a QOM initfn. > > This series is rebased onto Julien's ioport cleanups (touching on ISA > devices). > > It starts by preparing the "realized" property, wrapping qdev's initfn (04). > This means setting realized to true will not yet affect its children, as seen > in Paolo's previous patches. That can be implemented later when the realizefns > have been reviewed not to create new devices that would mess with recursive > child realization. (In the previous series we had recursive realization but > on my request dropped the hook-up of qdev due to the aforementioned quirks.) > > At that point there is a coexistence of QOM device realizefn and qdev initfn. > For the first time now I have set out to actually eliminate some qdev initfns, > that's what I chose ISA for. This consists of three parts, introducing > realizefns for ISADevices (28) and recursively for PITs (31) and for PICs > (34). > As seen for the PCI host bridge series, I've extracted general QOM cleanups > from the main conversion patch to arrive at a clean QOM'ish state while > hopefully keeping the main patches readable. > > This series also highlights an interesting find: Beyond the to-be-solved > CPUState, there is also a "realize" function for BusState (02), which is not > derived from DeviceState. :-) > With the device-centric approach taken here it would still be possible to add > "realized" properties to other types using their own infrastructure (e.g., a > hardcoded setter rather than a realizefn hook). > > Posted as an RFC to encourage bikeshedding, in particular about the type names > and macros introduced. Adding new header files to move them out of the source > files for, e.g., vl.c is left for a follow-up, but for instance I was unsure > about TYPE_ISA_FDC (should this be TYPE_ISA_FLOPPY_DRIVE_CONTROLLER as with > PCI_HOST_BRIDGE rather than PHB?), and naming of type names and functions is > highly inconsistent (e.g., isa_vga vs. vga_isa, or pic vs. i8259).
So far I've heard no comments on the main QOM/ISA part of the series... Anthony, did I understand you correctly wrt the method overriding? (PIC/PIT) Or did you have this differently in mind? Anyone any suggestions for improvement? If not, I'll send out a v2 this week, with qdev_free() either rebased onto Paolo or removal dropped. qbus was not further touched in the series, so I'd probably defer the qbus_realize() change. Branch below is rebased to match v1.3.0 + memory-ioport pull request. Regards, Andreas > > Available for viewing/testing at: > https://github.com/afaerber/qemu-cpu/commits/realize-qdev > git://github.com/afaerber/qemu-cpu.git realize-qdev [...] > Andreas Färber (34): > qdev: Eliminate qdev_free() in favor of QOM (depends on what we want to replace qdev_free() with) > qbus: QOM'ify qbus_realize() (unrelated since qbus did not get a "realized" property in this series) > qdev: Fold state enum into bool realized > qdev: Prepare "realized" property > isa: Split off instance_init for ISADevice > applesmc: QOM'ify > cirrus_vga: QOM'ify ISA Cirrus VGA > debugcon: QOM'ify ISA debug console > fdc: QOM'ify ISA floppy controller > i82374: QOM'ify > i8259: Fix PIC_COMMON() macro (applied already) > i8259: QOM cleanups > ide: QOM'ify ISA IDE > m48t59: QOM'ify ISA M48T59 NVRAM > mc146818rtc: QOM'ify > ne2000-isa: QOM'ify > parallel: QOM'ify > pc: QOM'ify port 92 > pckbd: QOM'ify > pcspk: QOM'ify > sb16: QOM'ify > serial: QOM'ify ISA serial > sga: QOM'ify > vga-isa: QOM'ify ISA VGA > vmmouse: QOM'ify > vmport: QOM'ify > wdt_ib700: QOM'ify > isa: Use realizefn for ISADevice > i8254: QOM'ify > kvm/i8254: QOM'ify some more > i8254: Convert PITCommonState to QOM realizefn > i8259: QOM'ify some more > kvm/i8259: QOM'ify some more > i8259: Convert PICCommonState to use QOM realizefn [snip] -- SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
