Re: [Qemu-devel] [RFC PATCH v3 00/19] ACPI memory hotplug

[Blue Swirl]

On Fri, Sep 21, 2012 at 11:17 AM, Vasilis Liaskovitis
<address@hidden> wrote:
> This is v3 of the ACPI memory hotplug functionality. Only x86_64 target is 
> supported
> for now.
>
> Overview:
>
> Dimm device layout is modeled with a new qemu command line
>
> "-dimm id=name,size=sz,node=pxm,populated=on|off"
>
> 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 normal device_add, device_del operations:
> Hot-add syntax: "device_add dimm,id=mydimm0"
> Hot-remove syntax: "dimm_del dimm,id=mydimm0"
>
> Changes v2->v3
>
> - qdev integration. Dimms are attached to a dimmbus. The dimmbus is a child
>   of i440fx device in the pc machine. Hot-add and hot-remove are done with 
> normal
>   device_add / device_del operations on the dimmbus. New commands "dimm_add" 
> and
>   "dimm_del" are obsolete. (In previous versions, dimms were always present 
> on the
>   qdev tree, and dimm_add/del simply meant allocating or deallocating memory 
> for
>   the devices. This version actually does hot-operations on the qdev tree)
> - Add _PS3 method to allow OSPM-induced hot operations.
> - pci-window calculation in Seabios takes dimms into account(for both 32-bit 
> and
>   64-bit windows)
> - rename new qmp commands: query-memory-total and query-memory-hotplug
> - balloon driver can see the hotplugged memory
>
> 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 (obsolete from v3 onwards)
>
> Issues:
>
> - A main blocker issue is windows guest functionality. The patchset does not 
> work for
> windows currently. My guess is the windows pnpmem driver does not like the
> seabios dimm device implementation (or the seabios dimm implementation is not
> fully ACPI-compliant). If someone can review the seabios patches or has any
> ideas to debug this, let me know.
>
> Testing on win2012 server RC or windows2008 consumer prerelease. When adding a
> DIMM, the device shows up in DeviceManager but does not work.
> Relevant messages:
>
> " This device cannot start. (Code 10)
> Device configured(memory.inf) (UserPnP eventID 400)
> Device installed (memory.inf) ACPI/PNP0C80\2&daba3ff&1 was configured
> Device not started(PNPMEM) (Kernel-PnP eventID 411, kernelID)
> Device ACPI\PNP0C80\2&daba3ff&1 had a problem starting Driver Name: memory.inf
> (c:\Windows\system32\DRIVERS\pnpmem.sys 6.2.8400 winmain_win8rc))
> Memory range:0x80000000 - 0x90000000 (Initial memory of VM is 2GB. The 
> hotplugged DIMM
>      was a 256GB with physical address range starting at 2GB )
> Conflicting device list: No conflicts. "
>
> Adding a 2nd or more dimms causes a crash (PNP_DETECTED_FATAL_ERROR with blue
> screen of death) and makes windows reboot. After this, the VM keeps rebooting 
> with
> ACPI_BIOS_ERROR. The VM refuses to boot anymore once a 2nd (or more) extra 
> dimm is
> plugged-in.
>
> - Is the dimmbus the correct way to go about integrating into qdev/qom? In a 
> v1
> comment, Anthony mentioned attaching dimms directly to an i440fx device as
> children. Is this possible without a bus?
>
> - Live migration works as long as the dimm layout (-dimm command line args) 
> are
> identical at the source and destination qemu command line. Patch 10/19
> creates the DimmDevice that corresponds to the unknown incoming ramblock.
> Ramblocks are migrated before qdev VMStates are migrated (the DimmDevice 
> structure
> currently does not define a VMStateDescription). So the DimmDevice is handled
> diferrently than other devices. If this is not acceptable, any suggestions on
> how should it be reworked?
>
> - Hot-operation notification lists need to be added to migration state.
>
> Please review. Could people state which other issues they consider blocker for
> including this upstream?

Please check the patches with checkpatch.pl, there are plenty of
missing braces and uses of __FUNCTION__ etc.

I also have other comments to specific patches, especially the
architecture does not look correct.

>
> Does this patchset need to wait for 1.4 or could this be considered for 1.3 
> (assuming
> blockers are resolved)? The patchset has been revised every few months, but
> I will provide quicker version updates onwards. I can also bring this up on a 
> weekly
> meeting agenda if needed.
>
> 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-v3
> http://github.com/vliaskov/seabios/commits/memhp-v3
>
> Vasilis Liaskovitis (12):
>   Implement dimm device abstraction
>   Implement "-dimm" command line option
>   acpi_piix4: Implement memory device hotplug registers
>   pc: calculate dimm physical addresses and adjust memory map
>   pc: Add dimm paravirt SRAT info
>   fix live-migration when "populated=on" is missing
>   Implement qmp and hmp commands for notification lists
>   Implement "info memory-total" and "query-memory-total"
>   balloon: update with hotplugged memory
>   Add _OST dimm support
>   Update dimm state on reset
>   Implement _PS3 for dimm
>
>  arch_init.c                 |   24 ++-
>  docs/specs/acpi_hotplug.txt |   54 ++++++
>  docs/specs/fwcfg.txt        |   28 +++
>  hmp-commands.hx             |    4 +
>  hmp.c                       |   24 +++
>  hmp.h                       |    2 +
>  hw/Makefile.objs            |    2 +-
>  hw/acpi_piix4.c             |  114 +++++++++++-
>  hw/dimm.c                   |  435 
> +++++++++++++++++++++++++++++++++++++++++++
>  hw/dimm.h                   |  101 ++++++++++
>  hw/pc.c                     |   55 ++++++-
>  hw/pc.h                     |    6 +
>  hw/pc_piix.c                |   20 ++-
>  hw/virtio-balloon.c         |   13 +-
>  monitor.c                   |   14 ++
>  qapi-schema.json            |   37 ++++
>  qemu-config.c               |   25 +++
>  qemu-options.hx             |    5 +
>  qmp-commands.hx             |   57 ++++++
>  sysemu.h                    |    1 +
>  vl.c                        |   51 +++++
>  21 files changed, 1051 insertions(+), 21 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
>   Subject: [PATCH 02/18] Add SSDT memory device support
>   acpi-dsdt: Implement functions for memory hotplug
>   acpi: generate hotplug memory devices
>   Add _OST dimm method
>   Implement _PS3 method for memory device
>   Calculate pcimem_start and pcimem64_start from SRAT entries
>
>  Makefile              |    2 +-
>  src/acpi-dsdt.dsl     |  135 ++++++++++++++++++++++++++++++-
>  src/acpi.c            |  216 ++++++++++++++++++++++++++++++++++++++++++++----
>  src/acpi.h            |    3 +
>  src/pciinit.c         |    6 +-
>  src/post.c            |    3 +
>  src/smp.c             |    4 +
>  src/ssdt-mem.dsl      |   73 +++++++++++++++++
>  tools/acpi_extract.py |   28 +++++++
>  9 files changed, 447 insertions(+), 23 deletions(-)
>  create mode 100644 src/ssdt-mem.dsl
>
>
> --
> 1.7.9
>