[Qemu-devel] [PATCH v4 00/14] MemoryDevice: use multi stage hotplug handlers

[David Hildenbrand <david@redhat.com>]

We can have devices that need certain other resources that are e.g.
system resources managed by the machine. We need a clean way to assign
these resources (without violating layers as brought up by Igor).

One example is virtio-mem/virtio-pmem. Both device types need to be
assigned some region in guest physical address space. This device memory
belongs to the machine and is managed by it. However, virito devices are
hotplugged using the hotplug handler their proxy device implements. So we
could trigger e.g. a PCI hotplug handler for virtio-pci or a CSS/CCW
hotplug handler for virtio-ccw. But definetly not the machine.

Now, we can route other devices through the machine hotplug handler, to
properly assign/unassign resources - like a portion in guest physical
address space.

v3 -> v4:
- Removed the s390x bits, will send that out separately (was just a proof
  that it works just fine with s390x)
- Fixed a typo and reworded a comment

v2 -> v3:
- Added "memory-device: introduce separate config option"
- Dropped "parent_bus" check from hotplug handler lookup functions
- "Handly" -> "Handle" in patch description.

v1 -> v2:
- Use multi stage hotplug handler instead of resource handler
- MemoryDevices only compiled if necessary (CONFIG_MEM_HOTPLUG)
- Prepare PC/SPAPR machines properly for multi stage hotplug handlers
- Route SPAPR unplug code via the hotunplug handler
- Directly include s390x support. But there are no usable memory devices
  yet (well, only my virtio-mem prototype)
- Included "memory-device: drop assert related to align and start of address
  space"

David Hildenbrand (13):
  memory-device: drop assert related to align and start of address space
  memory-device: introduce separate config option
  pc: prepare for multi stage hotplug handlers
  pc: route all memory devices through the machine hotplug handler
  spapr: prepare for multi stage hotplug handlers
  spapr: route all memory devices through the machine hotplug handler
  spapr: handle pc-dimm unplug via hotplug handler chain
  spapr: handle cpu core unplug via hotplug handler chain
  memory-device: new functions to handle plug/unplug
  pc-dimm: implement new memory device functions
  memory-device: factor out pre-plug into hotplug handler
  memory-device: factor out unplug into hotplug handler
  memory-device: factor out plug into hotplug handler

Igor Mammedov (1):
  qdev: let machine hotplug handler to override bus hotplug handler

 default-configs/i386-softmmu.mak   |   3 +-
 default-configs/ppc64-softmmu.mak  |   3 +-
 default-configs/x86_64-softmmu.mak |   3 +-
 hw/Makefile.objs                   |   2 +-
 hw/core/qdev.c                     |   6 +-
 hw/i386/pc.c                       | 102 ++++++++++++++++++++++-------
 hw/mem/Makefile.objs               |   4 +-
 hw/mem/memory-device.c             | 129 +++++++++++++++++++++++--------------
 hw/mem/pc-dimm.c                   |  48 ++++++--------
 hw/mem/trace-events                |   4 +-
 hw/ppc/spapr.c                     | 129 +++++++++++++++++++++++++++++++------
 include/hw/mem/memory-device.h     |  21 ++++--
 include/hw/mem/pc-dimm.h           |   3 +-
 include/hw/qdev-core.h             |  11 ++++
 qapi/misc.json                     |   2 +-
 15 files changed, 330 insertions(+), 140 deletions(-)

-- 
2.14.3