Re: [Qemu-devel] [RFC 00/34] QOM realize, device-only plus ISA conversion

[Anthony Liguori <anthony@codemonkey.ws>]

So there are 3-4 different series in here all rolled into one.  This
makes review a bit tedious.

I'd suggest:

1) Pull out all of the QOMification stuff into a separate series.
2) Pull out the style cleanups into another series
3) Pull out the introduction of realize/unrealize into a series
4) Pull out the ISA use of realize into another series.

Individually, each series looks very easy to merge.  The general
approach is right along what I was hoping for.

Regards,

Anthony Liguori

Andreas Färber <afaerber@suse.de> writes:

> 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).
>
> Available for viewing/testing at:
> https://github.com/afaerber/qemu-cpu/commits/realize-qdev
> git://github.com/afaerber/qemu-cpu.git realize-qdev
>
> Regards,
> Andreas
>
> Cc: Anthony Liguori <anthony@codemonkey.ws>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
>
> Cc: Julien Grall <julien.grall@citrix.com>
> Cc: Frederic Konrad <fred.konrad@greensocs.com>
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
> Cc: Kevin Wolf <kwolf@redhat.com>
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Cc: Markus Armbruster <armbru@redhat.com>
> Cc: Eduardo Habkost <ehabkost@redhat.com>
> Cc: Igor Mammedov <imammedo@redhat.com>
>
> Andreas Färber (34):
>   qdev: Eliminate qdev_free() in favor of QOM
>   qbus: QOM'ify qbus_realize()
>   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
>   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
>
>  hw/acpi_piix4.c      |    2 +-
>  hw/applesmc.c        |   45 +++++++++---------
>  hw/cirrus_vga.c      |   27 ++++++-----
>  hw/debugcon.c        |   34 +++++++++-----
>  hw/fdc.c             |   45 ++++++++++--------
>  hw/fdc.h             |    2 +
>  hw/i82374.c          |   25 +++++-----
>  hw/i8254.c           |   26 +++++++---
>  hw/i8254.h           |    7 ++-
>  hw/i8254_common.c    |   19 ++------
>  hw/i8254_internal.h  |    1 -
>  hw/i8259.c           |   64 +++++++++++++++++--------
>  hw/i8259_common.c    |   20 +++-----
>  hw/i8259_internal.h  |    7 +--
>  hw/ide/isa.c         |   55 +++++++++++++---------
>  hw/isa-bus.c         |   15 ++----
>  hw/isa.h             |    1 -
>  hw/kvm/i8254.c       |   59 +++++++++++++++--------
>  hw/kvm/i8259.c       |   38 ++++++++++++---
>  hw/m48t59.c          |   54 +++++++++++----------
>  hw/mc146818rtc.c     |   56 ++++++++++++----------
>  hw/mc146818rtc.h     |    2 +
>  hw/ne2000-isa.c      |   27 ++++++-----
>  hw/parallel.c        |   42 ++++++++++-------
>  hw/pc.c              |   26 +++++-----
>  hw/pc_piix.c         |    2 +-
>  hw/pci-hotplug.c     |    2 +-
>  hw/pci_bridge.c      |    2 +-
>  hw/pcie.c            |    2 +-
>  hw/pckbd.c           |   34 ++++++++------
>  hw/pcspk.c           |   21 +++++----
>  hw/pcspk.h           |    4 +-
>  hw/qdev-addr.c       |    2 +-
>  hw/qdev-core.h       |   12 ++---
>  hw/qdev-monitor.c    |    2 +-
>  hw/qdev-properties.c |   28 +++++------
>  hw/qdev.c            |  128 ++++++++++++++++++++++++++++++++++----------------
>  hw/sb16.c            |   35 +++++++++-----
>  hw/scsi-bus.c        |    4 +-
>  hw/serial-isa.c      |   33 +++++++------
>  hw/serial-pci.c      |    4 +-
>  hw/serial.c          |    6 +--
>  hw/serial.h          |    3 +-
>  hw/sga.c             |   19 ++++----
>  hw/shpc.c            |    2 +-
>  hw/usb/bus.c         |    7 +--
>  hw/usb/dev-storage.c |    2 +-
>  hw/usb/host-linux.c  |    2 +-
>  hw/vga-isa.c         |   46 +++++++++---------
>  hw/vmmouse.c         |   24 +++++-----
>  hw/vmport.c          |   24 ++++++----
>  hw/wdt_ib700.c       |   22 +++++----
>  hw/xen_platform.c    |    2 +-
>  53 Dateien geändert, 692 Zeilen hinzugefügt(+), 481 Zeilen entfernt(-)
>
> -- 
> 1.7.10.4