[Qemu-devel] [PATCH 00/16 RFC v6] ACPI memory hotplug

[Igor Mammedov]

As opposed to previous approach,
This series allows to hotplug 'arbitrary' DIMM devices specifying size,
NUMA node mapping, slot and address where to map it, at runtime.

Due to ACPI limitation there is need to specify a number of possible
DIMM devices. For this task -m option was extended to support
following format:

  -m [mem=]RamSize[,slots=N,maxmem=M]

To allow memory hotplug user must specify a pair additional parameters:
    'slots' - number of possible increments
    'maxmem' - max possible total memory size QEMU is allowed to use,
               including RamSize.

minimal monitor command syntax to hotplug DIMM device:

  device_add dimm,id=dimmX

DIMM device provides following properties that could be used with
device_add / -device to alter default behavior:

  id    - unique string identifying device [mandatory]
  slot  - number in range [0-slots) [optional], if not specified
          the first free slot is used
  node  - NUMA node id [optional] (default: 0)
  size  - amount of memory to add [optional] (default: 1Gb)
  start - guest's physical address where to plug DIMM [optional],
          if not specified the first gap in hotplug memory region
          that fits DIMM is used

 -device option could be used for adding potentially hotunplugable DIMMs
and also for specifying hotplugged DIMMs in migration case (not tested).

Current implementation supports only x86-64 variant and places hotplug
memory region above 4Gb before 64-bit PCI hole.

Tested guests:
 - Fedora 19x64
 - Windows 2012DCx64
 - Windows 2008DCx64

Known limitations/bugs/TODOs:
 - only hot-add supported
 - q35 is not supported yet
 - max number of supported DIMM devices 255 (due to ACPI object name
   limit), could be increased creating several containers and putting
   DIMMs there. (exercise for future) 
 - failed hotplug action consumes 1 slot (device_add doesn't delete
   device if realize failed)
 - e820 table doesn't include DIMM devices added with -device /
   (or after reboot devices added with device_add)
 - Windows 2008 remembers DIMM configuration, so if DIMM with other
   start/size is added into the same slot, it refuses to use it insisting
   on old mapping.

Series is based on mst's acpi tables branch and requires corresponding
seabios tree:
  git://git.kernel.org/pub/scm/virt/kvm/mst/seabios.git acpi

Git tree for testing available at:
  https://github.com/imammedo/qemu/commits/memhp-v6

Example QEMU cmd line:
  qemu-system-x86_64 -enable-kvm -monitor unix:/tmp/mon,server,nowait \ 
     -m 4096,slots=4,maxmem=8G -L /custome_seabios guest.img

PS:
  Windows guest requires SRAT table for hotplug to work so add extra option:
   -numa node
  to QEMU command line.

Igor Mammedov (13):
  pc: use pci_hole64 info consistently
  vl: set default ram_size during variable initialization
  vl: convert -m to qemu_opts_parse()
  dimm: map DimmDevice into DimBus provided address space
  pc: piix: make hotplug memory gap in high memory
  pc: i440fx: add DimmBus to chipset and map it into hotplug memory
    region
  dimm: add busy slot check and slot auto-allocation
  dimm: add busy address check and address auto-allocation
  dimm: introduce memory added notifier
  acpi/piix4: introduce memory hot-plug interface QEMU<->ACPI BIOS
  pc: ACPI BIOS: implement memory hotplug interface
  pc: update acpi-dsdt.hex.generated and add ssdt-mem.hex.generated
  pc: ACPI BIOS: reserve SRAT entry for hotplug mem hole

Vasilis Liaskovitis (3):
  qapi: make visit_type_size fallback to type_int
  qdev: Add SIZE type to qdev properties
  dimm: implement dimm device abstraction

 default-configs/x86_64-softmmu.mak |    1 +
 docs/specs/acpi_mem_hotplug.txt    |   38 +++
 hw/Makefile.objs                   |    1 +
 hw/acpi/piix4.c                    |  170 ++++++++++-
 hw/core/qdev-properties.c          |   55 +++
 hw/i386/Makefile.objs              |    2 +-
 hw/i386/acpi-build.c               |   62 +++-
 hw/i386/acpi-dsdt-mem-hotplug.dsl  |  144 ++++++++
 hw/i386/acpi-dsdt.dsl              |    5 +-
 hw/i386/acpi-dsdt.hex.generated    |  633 +++++++++++++++++++++++++++++++++++-
 hw/i386/pc.c                       |   10 +-
 hw/i386/pc_piix.c                  |    5 +-
 hw/i386/ssdt-mem.dsl               |   76 +++++
 hw/i386/ssdt-mem.hex.generated     |  161 +++++++++
 hw/mem-hotplug/Makefile.objs       |    1 +
 hw/mem-hotplug/dimm.c              |  244 ++++++++++++++
 hw/pci-host/piix.c                 |   29 ++-
 hw/pci-host/q35.c                  |    7 +-
 include/hw/i386/pc.h               |    4 +-
 include/hw/mem-hotplug/dimm.h      |   91 +++++
 include/hw/qdev-properties.h       |    3 +
 include/qemu/option.h              |    2 +
 include/sysemu/sysemu.h            |    3 +
 qapi/qapi-visit-core.c             |   11 +-
 qemu-options.hx                    |    9 +-
 stubs/Makefile.objs                |    1 +
 stubs/memory_hotplug.c             |    6 +
 util/qemu-option.c                 |    2 +-
 vl.c                               |   60 +++-
 29 files changed, 1782 insertions(+), 54 deletions(-)
 create mode 100644 docs/specs/acpi_mem_hotplug.txt
 create mode 100644 hw/i386/acpi-dsdt-mem-hotplug.dsl
 create mode 100644 hw/i386/ssdt-mem.dsl
 create mode 100644 hw/i386/ssdt-mem.hex.generated
 create mode 100644 hw/mem-hotplug/Makefile.objs
 create mode 100644 hw/mem-hotplug/dimm.c
 create mode 100644 include/hw/mem-hotplug/dimm.h
 create mode 100644 stubs/memory_hotplug.c