Re: [Qemu-devel] [PATCH 0/7] Refactor PCI/SHPC/PCIE hotplug to use a more generic hotplug API

[Igor Mammedov <imammedo@redhat.com>]

On Fri, 06 Dec 2013 18:31:55 +0100
Paolo Bonzini <pbonzini@redhat.com> wrote:

> Il 06/12/2013 18:03, Igor Mammedov ha scritto:
> > Series is replacement for a more simple attempt to generalize hotplug API
> > http://lists.gnu.org/archive/html/qemu-devel/2013-11/msg02529.html
> > promted by Paolo in this patch review.
> > --
> > 
> > Refactor PCI specific hotplug API to a more generic/reusable one.
> > Model it after SCSI-BUS like hotplug API replacing single hotplug
> > callback with hotplug/hot_unplug pair of callbacks as suggested by
> > Paolo.
> > Difference between SCSI-BUS and this approach is that the former
> > is BUS centric while the latter is device centred. Which is evolved
> > from the fact that hotplug callbacks used by ACPI/SHPC/PCIE are
> > implemented by devices rather than by bus and bus serves only as
> > a proxy to forward event to hotplug device.
> > Memory hotplug also exposes tha same usage pattern hence an attempt
> > to generalize hotplug API.
> > 
> > Refactoring also simplifies wiring of a hotplug device with a bus,
> > all it needs is to set "hotplug-device" link on bus, which
> > would potentially allow to do it from configuration file,
> > there is not need to setup hotplug device callbacks on bus
> > synce it can get them via HOTPLUG_DEVICE API of "hotplug-device"
> > target.
> > 
> > In addition device centred hotplug API may be used by bus-less
> > hotplug implementations as well if it's decided to use
> > link<foo...> instead of bus.
> > 
> > Patches 4-7 are should be merged as one and are split only for
> > simplifying review (they compile fine but PCI hotplug is broken
> > until the last patch applyed).
> > 
> > git tree for testing:
> > https://github.com/imammedo/qemu/commits/hotplug_dev_inf_v1
> > 
> > tested only ACPI hotplug with following HMP commands:
> > ==
> > netdev_add user,id=n1
> > device_add e1000,id=e1,netdev=n1
> > device_del e1
> > ==
> > 
> > Igor Mammedov (7):
> >   define hotplug interface
> >   qdev: add to BusState "hotplug-device" link
> >   hw/acpi: move typeinfo to the file end
> >   acpi/piix4pm: convert ACPI PCI hotplug to use hotplug-device
> >     interface
> >   pci/shpc: convert SHPC hotplug to use hotplug-device interface
> >   pci/pcie: convert PCIE hotplug to use hotplug-device interface
> >   hw/pci: convert PCI bus to use "hotplug-device" interface.
> > 
> >  hw/acpi/piix4.c                |  143 +++++++++++++++++++++-------------------
> >  hw/core/Makefile.objs          |    1 +
> >  hw/core/hotplug.c              |   25 +++++++
> >  hw/core/qdev.c                 |    4 +
> >  hw/pci-bridge/pci_bridge_dev.c |    9 +++
> >  hw/pci/pci.c                   |   70 ++++++++++++++-----
> >  hw/pci/pcie.c                  |   73 +++++++++++++-------
> >  hw/pci/pcie_port.c             |    8 ++
> >  hw/pci/shpc.c                  |  132 ++++++++++++++++++++++++-------------
> >  include/hw/hotplug.h           |   50 ++++++++++++++
> >  include/hw/pci/pci.h           |   10 ---
> >  include/hw/pci/pci_bus.h       |    2 -
> >  include/hw/pci/pcie.h          |    4 +
> >  include/hw/pci/shpc.h          |    7 ++
> >  include/hw/qdev-core.h         |    4 +
> >  15 files changed, 372 insertions(+), 170 deletions(-)
> >  create mode 100644 hw/core/hotplug.c
> >  create mode 100644 include/hw/hotplug.h
> > 
> 
> I didn't look closely at patches 4-6, but it looks very nice and
> extensible.  I will convert SCSI to use this too when it goes in.
> 
> Can you pick up my qom patches for interfaces too ("qom: fix
> registration of QOM interfaces")?
sure.

> 
> Paolo