[Qemu-devel] [PATCH 00/27 RFC v7] ACPI memory hotplug

[Igor Mammedov <imammedo@redhat.com>]

---
What's new since v6:

* DIMM device is split to backend and frontend. Therefore following
  command/options were added for supporting it:

  For memdev backend:
      CLI: -memdev-add
      Monitor/QMP: memdev-add
          with options: 'id' and 'size'
  For dimm frontend:
      option "size" became readonly, pulling it's size from attached backend
      added option "memdev" for specifying backend by 'id'

* Added Q35 support
* Added support for 32 bit guests
* build for i386 emulator (not tested)
---

This series allows to hotplug 'arbitrary' DIMM devices specifying size,
NUMA node mapping (guest side), 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 of 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:

  memdev-add id=memX,size=1G
  device_add dimm,id=dimmX,memdev=memX

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, readonly derived from backing memdev
  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.

Tested guests:
 - RHEL 6x64
 - Windows 2012DCx64
 - Windows 2008DCx64
 - Windows 2008DCx32

Known limitations/bugs/TODOs:
 - only hot-add supported
 - 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 properly 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 PCI tree and requires following SeaBIOS patch:
  http://patchwork.ozlabs.org/patch/292614/
  on top of patches to load ACPI tables from QEMU
  working SeaBIOS tree for testing is available at:
    https://github.com/imammedo/seabios/commits/memhp-wip

QEMU git tree for testing is available at:
  https://github.com/imammedo/qemu/commits/memory-hotplug-v7

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 (26):
  acpi: factor out common pm_update_sci() into acpi core
  rename pci_hotplug_fn to hotplug_fn and make it available for other
    devices
  pc: add 'etc/reserved-memory-end' fw_cfg interface for SeaBIOS
  vl: convert -m to qemu_opts_parse()
  qapi: add SIZE type parser to string_input_visitor
  get reference to /backend container via qemu_get_backend()
  add memdev backend infrastructure
  dimm: map DimmDevice into DimBus provided address space
  dimm: add busy slot check and slot auto-allocation
  dimm: add busy address check and address auto-allocation
  dimm: add hotplug callback to DimmBus
  acpi: memory hotplug ACPI hardware implementation
  acpi: initialize memory hotplug ACPI PIIX4 hardware
  acpi: piix4: add memory-hotplug-io-base property to piix4_pm
  acpi: ich9: allow guest to clear SCI rised by GPE
  acpi: initialize memory hotplug ACPI ICH9 hardware
  acpi: ich9: add memory-hotplug-io-base property to ich9_pm
  acpi: piix4/ich9: add optional vmstate field for MemHotplugState
    migration
  pc: piix: make PCII440FXState type public
  pc: add memory hotplug 440fx machine
  pc: add memory hotplug Q35 machine
  pc: ACPI BIOS: implement memory hotplug interface
  pc: ACPI BIOS: add ssdt-mem.hex.generated and update
    ssdt-misc.hex.generated
  pc: ACPI BIOS: use enum for defining memory affinity flags
  pc: ACPI BIOS: reserve SRAT entry for hotplug mem hole
  pc: ACPI BIOS: make GPE.3 handle memory hotplug event on PIIX and Q35
    machines

Vasilis Liaskovitis (1):
  dimm: implement dimm device abstraction

 backends/Makefile.objs             |    2 +
 backends/hostmem.c                 |  275 +++++++++++
 backends/hostmem_compat_ram.c      |   42 ++
 default-configs/i386-softmmu.mak   |    1 +
 default-configs/x86_64-softmmu.mak |    1 +
 docs/specs/acpi_mem_hotplug.txt    |   38 ++
 hmp-commands.hx                    |   13 +
 hw/Makefile.objs                   |    1 +
 hw/acpi/core.c                     |  189 ++++++++
 hw/acpi/ich9.c                     |   57 ++-
 hw/acpi/pcihp.c                    |    6 +-
 hw/acpi/piix4.c                    |   91 +++--
 hw/i386/Makefile.objs              |    3 +-
 hw/i386/acpi-build.c               |   91 ++++-
 hw/i386/acpi-dsdt.dsl              |    5 +-
 hw/i386/pc.c                       |   90 ++++-
 hw/i386/pc_piix.c                  |    7 +-
 hw/i386/pc_q35.c                   |    4 +
 hw/i386/q35-acpi-dsdt.dsl          |    5 +-
 hw/i386/ssdt-mem.dsl               |   75 +++
 hw/i386/ssdt-mem.hex.generated     |  197 ++++++++
 hw/i386/ssdt-misc.dsl              |  179 ++++++++
 hw/i386/ssdt-misc.hex.generated    |  881 +++++++++++++++++++++++++++++++++++-
 hw/mem/Makefile.objs               |    1 +
 hw/mem/dimm.c                      |  321 +++++++++++++
 hw/pci-host/piix.c                 |   36 +-
 hw/pci-host/q35.c                  |   19 +-
 hw/pci/pci.c                       |   12 +-
 hw/pci/pcie.c                      |    7 +-
 hw/pci/shpc.c                      |    9 +-
 include/hw/acpi/acpi.h             |   42 ++
 include/hw/acpi/ich9.h             |    6 +
 include/hw/acpi/pcihp.h            |    2 +-
 include/hw/acpi/piix4.h            |    2 +
 include/hw/i386/pc.h               |   33 ++-
 include/hw/mem/dimm.h              |   99 ++++
 include/hw/pci-host/piix.h         |   29 ++
 include/hw/pci-host/q35.h          |    1 +
 include/hw/pci/pci.h               |   11 +-
 include/hw/pci/pci_bus.h           |    2 +-
 include/hw/qdev-core.h             |    9 +
 include/sysemu/hostmem.h           |  102 +++++
 include/sysemu/sysemu.h            |    3 +
 monitor.c                          |    1 +
 qapi-schema.json                   |   18 +
 qapi/string-input-visitor.c        |   18 +
 qemu-options.hx                    |   16 +-
 qmp-commands.hx                    |   27 ++
 ui/console.c                       |    3 +-
 vl.c                               |   98 ++++-
 50 files changed, 3040 insertions(+), 140 deletions(-)
 create mode 100644 backends/hostmem.c
 create mode 100644 backends/hostmem_compat_ram.c
 create mode 100644 docs/specs/acpi_mem_hotplug.txt
 create mode 100644 hw/i386/ssdt-mem.dsl
 create mode 100644 hw/i386/ssdt-mem.hex.generated
 create mode 100644 hw/mem/Makefile.objs
 create mode 100644 hw/mem/dimm.c
 create mode 100644 include/hw/mem/dimm.h
 create mode 100644 include/hw/pci-host/piix.h
 create mode 100644 include/sysemu/hostmem.h