[SeaBIOS] [RFC PATCH v2 00/21] ACPI memory hotplug

Vasilis Liaskovitis vasilis.liaskovitis at profitbricks.com
Wed Jul 11 12:31:45 CEST 2012


This is v2 of the ACPI memory hotplug prototype for x86_64 target.

Changes v1->v2

- memory map is automatically calculated for hotplug dimms. Dimms are added from
top-of-memory skipping the pci hole at [PCI_HOLE_START, 4G).
- Renamed from "-memslot" to "-dimm". Commands changed to "dimm_add", "dimm_del".
- Seabios ejection array reduced to a byte. Use extraction macros for dimm ssdt.
- additional SRAT paravirt info does not break previous SRAT fw_cfg layout.
- Documentation of new acpi_piix4 registers and paravirt data.
- add ACPI _OST support for _OST enabled guests. This allows qemu to receive
notification for success / failure of memory hot-add and hot-remove operations.
Guest needs to support _OST (https://lkml.org/lkml/2012/6/25/321)
- add monitor info command to report total guest memory (initial + hot-added)
- add command line options and monitor commands for batch dimm creation/population

Overview:

Dimm devices are modeled with a new qemu command line 

"-dimm id=name,size=sz,node=pxm,populated=on|off"

As already mentioned, the starting physical address for all dimms is calculated
automatically from top of memory, skipping the pci hole at [PCI_HOLE_START, 4G).
Node is defining numa proximity for this dimm. When not defined it defaults
to zero.
"-dimm id=dimm0,size=512M,node=0,populated=off"
will define a 512M memory slot belonging to numa node 0.

Dimms are added or removed with a new hmp command "dimm_add/dimm_del":
Hot-add syntax: "dimm_add id"
Hot-remove syntax: "dimm_del id"

Issues:

- Live migration works as long as populated field is changed to "on" for
hotplugged dimms at the destination qemu command line (patch 12/21 lifts
this requirement). The DimmState structure does not yet define a
VMStateDescription, but i assume this is the preferred way to pass state
for migration.

- Dimms are abstracted as qdevices attached to the main system bus. However,
memory hotplugging has its own side channel ignoring main_system_bus's hotplug
incapability. A cleaner integration is still needed, probably attaching memory
devices as children-links of an acpi-capable device (in the pc case acpi_piix4)
instead of the system bus (TBD). Then device_add/device_del instead of new
commands can hopefully be used.

Comments/review welcome.

series is based on uq/master for qemu-kvm, and master for seabios. Can be found
also at:
http://github.com/vliaskov/qemu-kvm/commits/memhp-v2
http://github.com/vliaskov/seabios/commits/memhp-v2

Vasilis Liaskovitis (14):
  dimm: Implement memory device abstraction
  acpi_piix4: Implement memory device hotplug registers
  pc: calculate dimm physical addresses and adjust memory map
  pc: Add dimm paravirt SRAT info
  Implement "-dimm" command line option
  Implement dimm_add and dimm_del commands for hmp and qmp
  fix live-migration when "populated=on" is missing
  Implement memory hotplug notification lists
  acpi_piix4: _OST dimm support
  acpi_piix4: Update dimm state on VM reboot
  acpi_piix4: Update dimm bitmap state on hot-remove fail
  Implement "info memtotal" and "query-memtotal"
  Implement -dimms, -dimmspop command line options
  Implement mem_increase, mem_decrease hmp/qmp commands

 arch_init.c                 |   23 ++-
 docs/specs/acpi_hotplug.txt |   46 +++++
 docs/specs/fwcfg.txt        |   28 +++
 hmp-commands.hx             |   67 +++++++
 hmp.c                       |   24 +++
 hmp.h                       |    2 +
 hw/Makefile.objs            |    2 +-
 hw/acpi_piix4.c             |  131 ++++++++++++-
 hw/dimm.c                   |  449 +++++++++++++++++++++++++++++++++++++++++++
 hw/dimm.h                   |   72 +++++++
 hw/pc.c                     |   94 +++++++++-
 hw/pc.h                     |    6 +
 hw/pc_piix.c                |   18 ++-
 monitor.c                   |   35 ++++
 monitor.h                   |    5 +
 qapi-schema.json            |   38 ++++
 qemu-config.c               |   70 +++++++
 qemu-options.hx             |   15 ++
 qmp-commands.hx             |  137 +++++++++++++
 sysemu.h                    |    1 +
 vl.c                        |  122 ++++++++++++-
 21 files changed, 1368 insertions(+), 17 deletions(-)
 create mode 100644 docs/specs/acpi_hotplug.txt
 create mode 100644 docs/specs/fwcfg.txt
 create mode 100644 hw/dimm.c
 create mode 100644 hw/dimm.h

Vasilis Liaskovitis (7):
  Add ACPI_EXTRACT_DEVICE* macros
  Add SSDT memory device support
  acpi-dsdt: Implement functions for memory hotplug.
  acpi: generate hotplug memory devices.
  pciinit: Fix pcimem_start value
  acpi_dsdt: Support _OST dimm method
  acpi_dsdt: Revert internal dimm state on _OST failure
 
 Makefile              |    2 +-
 src/acpi-dsdt.dsl     |  120 ++++++++++++++++++++++++++++++++++++-
 src/acpi.c            |  158 +++++++++++++++++++++++++++++++++++++++++++++++--
 src/pciinit.c         |    2 +-
 src/ssdt-mem.dsl      |   69 +++++++++++++++++++++
 tools/acpi_extract.py |   28 +++++++++
 6 files changed, 369 insertions(+), 10 deletions(-)
 create mode 100644 src/ssdt-mem.dsl



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