Re: [Qemu-devel] [PATCH v4 00/33] pc: ACPI memory hotplug

[Michael S. Tsirkin]

On Mon, Jun 02, 2014 at 03:24:56PM +0200, Igor Mammedov wrote:
> NOTE to commiter:
>  * update precompiled ACPI hex files for iasl-less hosts
>    and ACPI tables test to match new ACPI tables.

Applied, thanks everyone!


> What's new since v10:
>  * rename DimmDevice to PCDIMMDevice
>  * allow anonymous DIMMs
>  * fix error handling in hostmemory_backend_set_size()
>  * fix ACPI read callback for case when guest tries to read
>    addr/length from slot without a present DIMM
> 
> What's new since v9:
>  * drop usage of error_is_set()
>  * exit QEMU if it's started with memory hotplug but
>    compat machine doesn't support it
>  * rename cpu_hotplug_defs.h to pc-hotplug.h
>  * use subsection when migrating acpi memory hotplug state
>  * add property to PC_MACHINE for getting hotplug memory region size
> 
> What's new since v8:
>  * rebased on top of Marcel's QOMyfing machine work
>     depends on patch from qom-next:
>      "machine: Conversion of QEMUMachineInitArgs to MachineState"
>  * fixed QEMU abort if it's running in daemonized mode
>  * fixed leak in memdev backend
>  * introduced custom PCMachine
>  * DIMM devices are now bus-less and use bus-less hotplug method
>  * DIMMDevice: renamed property/field 'start' to 'addr'
>  * ACPI tables:
>    * avoid punching hotples in PCI CRS by placing
>      MEMORY_HOPTLUG_DEVICE on PCI0 bus
>  * incorporated most of comments/fixes from reviewers
> 
> What's new since v7:
> * Per Andreas' suggestion dropped DIMMBus concept.
> * Added hotplug binding for bus-less devices
> * DIMM device is split to backend and frontend. Therefore following
>   command/options were added for supporting it:
> 
>   For memory-ram backend:
>       CLI: -object-add memory-ram,
>           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'
> 
> * dropped support for 32 bit guests
> * failed hotplug action doesn't consume 1 slot anymore
> * vaious fixes adressing reviewer's comments most of them in ACPI part
> ---
> 
> 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:
> 
>   object_add memory-ram,id=memX,size=1G
>   device_add pc-dimm,id=dimmX,memdev=memX
> 
> pc-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
>   addr - 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
> 
> Known limitations/bugs/TODOs:
>  - hot-remove is not supported, yet
>  - max number of supported DIMM devices 256 (due to ACPI object name
>    limit), could be increased creating several containers and putting
>    DIMMs there. (exercise for future) 
>  - 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
>    addr/size is added into the same slot, it refuses to use it insisting
>    on old mapping.
> 
> QEMU git tree for testing is available at:
>   https://github.com/imammedo/qemu/commits/memory-hotplug-v11
> 
> Example QEMU cmd line:
>   qemu-system-x86_64 -enable-kvm -monitor unix:/tmp/mon,server,nowait \ 
>      -m 4096,slots=4,maxmem=8G guest.img
> 
> PS:
>   Windows guest requires SRAT table for hotplug to work so add an extra 
> option:
>    -numa node
> 
> Igor Mammedov (32):
>   pc: create custom generic PC machine type
>   pc: ACPI BIOS: use enum for defining memory affinity flags
>   object_add: allow completion handler to get canonical path
>   vl.c: daemonize before guest memory allocation
>   add memdev backend infrastructure
>   vl.c: extend -m option to support options for memory hotplug
>   qdev: hotplug for buss-less devices
>   qdev: expose DeviceState.hotplugged field as a property
>   memory: add memory_region_is_mapped() API
>   pc-dimm: do not allow to set already used memdev
>   pc: initialize memory hotplug address space
>   pc: exit QEMU if number of slots more than supported 256
>   pc: add 'etc/reserved-memory-end' fw_cfg interface for SeaBIOS
>   pc: exit QEMU if compat machine doesn't support memory hotlpug
>   pc: add memory hotplug handler to PC_MACHINE
>   pc-dimm: add busy address check and address auto-allocation
>   pc-dimm: add busy slot check and slot auto-allocation
>   acpi: rename cpu_hotplug_defs.h to pc-hotplug.h
>   acpi: memory hotplug ACPI hardware implementation
>   trace: add acpi memory hotplug IO region events
>   trace: pc: add PC_DIMM slot & address allocation
>   acpi:piix4: allow plug/unlug callbacks handle not only PCI devices
>   acpi:piix4: add memory hotplug handling
>   pc: ich9 lpc: make it work with global/compat properties
>   acpi:ich9: add memory hotplug handling
>   pc: migrate piix4 & ich9 MemHotplugState
>   pc: add acpi-device link to PCMachineState
>   pc: propagate memory hotplug event to ACPI device
>   pc: ACPI BIOS: implement memory hotplug interface
>   pc: add "hotplug-memory-region-size" property to PC_MACHINE
>   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):
>   pc: implement pc-dimm device abstraction
> 
>  backends/Makefile.objs             |    2 +
>  backends/hostmem-ram.c             |   54 ++++++++
>  backends/hostmem.c                 |   97 +++++++++++++++
>  default-configs/i386-softmmu.mak   |    1 +
>  default-configs/x86_64-softmmu.mak |    1 +
>  docs/specs/acpi_mem_hotplug.txt    |   44 +++++++
>  hw/Makefile.objs                   |    1 +
>  hw/acpi/Makefile.objs              |    1 +
>  hw/acpi/ich9.c                     |   62 ++++++++++
>  hw/acpi/memory_hotplug.c           |  187 ++++++++++++++++++++++++++++
>  hw/acpi/piix4.c                    |   74 ++++++++++--
>  hw/core/qdev.c                     |   30 +++++
>  hw/i386/Makefile.objs              |    3 +-
>  hw/i386/acpi-build.c               |   75 ++++++++++-
>  hw/i386/acpi-dsdt.dsl              |    7 +-
>  hw/i386/pc.c                       |  227 ++++++++++++++++++++++++++++++++++-
>  hw/i386/pc_piix.c                  |   51 +++++---
>  hw/i386/pc_q35.c                   |   25 +++-
>  hw/i386/q35-acpi-dsdt.dsl          |    7 +-
>  hw/i386/ssdt-mem.dsl               |   77 ++++++++++++
>  hw/i386/ssdt-misc.dsl              |  164 +++++++++++++++++++++++++
>  hw/isa/lpc_ich9.c                  |   33 +++++-
>  hw/mem/Makefile.objs               |    1 +
>  hw/mem/pc-dimm.c                   |  236 
> ++++++++++++++++++++++++++++++++++++
>  hw/mips/mips_malta.c               |    2 +-
>  include/exec/memory.h              |    8 ++
>  include/hw/acpi/acpi.h             |    6 +
>  include/hw/acpi/cpu_hotplug.h      |    2 +-
>  include/hw/acpi/cpu_hotplug_defs.h |   32 -----
>  include/hw/acpi/ich9.h             |    4 +
>  include/hw/acpi/memory_hotplug.h   |   37 ++++++
>  include/hw/acpi/pc-hotplug.h       |   56 +++++++++
>  include/hw/boards.h                |   10 ++
>  include/hw/i386/pc.h               |   64 ++++++++++-
>  include/hw/mem/pc-dimm.h           |   79 ++++++++++++
>  include/sysemu/hostmem.h           |   60 +++++++++
>  memory.c                           |   10 ++-
>  qemu-options.hx                    |    9 +-
>  qmp.c                              |   11 ++-
>  trace-events                       |   17 +++
>  vl.c                               |   64 +++++++++-
>  41 files changed, 1829 insertions(+), 102 deletions(-)
>  create mode 100644 backends/hostmem-ram.c
>  create mode 100644 backends/hostmem.c
>  create mode 100644 docs/specs/acpi_mem_hotplug.txt
>  create mode 100644 hw/acpi/memory_hotplug.c
>  create mode 100644 hw/i386/ssdt-mem.dsl
>  create mode 100644 hw/mem/Makefile.objs
>  create mode 100644 hw/mem/pc-dimm.c
>  delete mode 100644 include/hw/acpi/cpu_hotplug_defs.h
>  create mode 100644 include/hw/acpi/memory_hotplug.h
>  create mode 100644 include/hw/acpi/pc-hotplug.h
>  create mode 100644 include/hw/mem/pc-dimm.h
>  create mode 100644 include/sysemu/hostmem.h