Re: [Qemu-devel] [PATCH v4 00/11] pc-dimm: factor out MemoryDevice

[Michael S. Tsirkin]

On Mon, Apr 23, 2018 at 06:51:15PM +0200, David Hildenbrand wrote:
> Right now we can only map PCDIMM/NVDIMM into guest address space. In the
> future, we might want to do the same for virtio devices - e.g.
> virtio-pmem or virtio-mem. Especially, they should be able to live side
> by side to each other.
> 
> E.g. the virto based memory devices regions will not be exposed via ACPI
> and friends. They will be detected just like other virtio devices and
> indicate the applicable memory region. This makes it possible to also use
> them on architectures without memory device detection support (e.g. s390x).
> 
> Let's factor out the memory device code into a MemoryDevice interface.
> 
> Please note that the "slots" assignment code is not relevant for memory
> devices that will not be exposed via ACPI or similar. That's why that
> part won't be exposed. KVM/vhost "slots" for memory regions are still
> necessary but don't have to be manually specified (e.g. the slot number
> doesn't mather).
> 
> So we are basically converting the hotplug memory region to a memory device
> region. I have patches that also set up such a region for s390x.

Reviewed-by: Michael S. Tsirkin <address@hidden>

Who's merging this? Eduardo?

> v3 -> v4:
> - "pc-dimm: factor out MemoryDevice interface"
> -- dropped the "errp" parameter from the interface functions
> -- made as many pointers const as I could :)
> -- s/built/build/
> - machine: make MemoryHotplugState accessible via the machine
> -- State now kept via a pointer, not queried.
> -- Added patches that rename the type and cleanup the terminology for
>    spapr and pc
> - Split up the big "pc-dimm: factor out address space logic into MemoryDevice
>   code" into sub patches
> --  We now pass the machine to the pc-dimm and MemoryDevice plug/unplug
>     functions, so we can avoid qdev_get_machine()
> -- Moved some checks around as requested by Igor
> - Added a patch to make maxmem not depend on slots
> 
> v2 -> v3:
> - "pc-dimm: factor out MemoryDevice interface"
> --> Lookup both classes when comparing (David Gibson)
> 
> v1 -> v2:
> - Fix compile issues on ppc (still untested  )
> 
> 
> David Hildenbrand (11):
>   pc-dimm: factor out MemoryDevice interface
>   machine: make MemoryHotplugState accessible via the machine
>   pc-dimm: no need to pass the memory region
>   pc-dimm: pass in the machine and to the MemoryHotplugState
>   pc-dimm: factor out address search into MemoryDevice code
>   pc-dimm: factor out capacity and slot checks into MemoryDevice
>   pc-dimm: move actual plug/unplug of a memory region to MemoryDevice
>   machine: rename MemoryHotplugState to DeviceMemoryState
>   pc: rename "hotplug memory" terminology to "device memory"
>   spapr: rename "hotplug memory" terminology to "device memory"
>   vl: allow 'maxmem' without 'slot'
> 
>  hw/i386/acpi-build.c                         |   7 +-
>  hw/i386/pc.c                                 |  65 +++---
>  hw/mem/Makefile.objs                         |   1 +
>  hw/mem/memory-device.c                       | 275 ++++++++++++++++++++++++
>  hw/mem/pc-dimm.c                             | 304 
> +++++++--------------------
>  hw/ppc/spapr.c                               |  65 +++---
>  hw/ppc/spapr_hcall.c                         |   7 +-
>  hw/ppc/spapr_rtas_ddw.c                      |   5 +-
>  include/hw/boards.h                          |  12 ++
>  include/hw/i386/pc.h                         |   3 +-
>  include/hw/mem/memory-device.h               |  51 +++++
>  include/hw/mem/pc-dimm.h                     |  27 +--
>  include/hw/ppc/spapr.h                       |   5 +-
>  numa.c                                       |   3 +-
>  qmp.c                                        |   4 +-
>  stubs/Makefile.objs                          |   2 +-
>  stubs/{qmp_pc_dimm.c => qmp_memory_device.c} |   4 +-
>  vl.c                                         |  19 +-
>  18 files changed, 506 insertions(+), 353 deletions(-)
>  create mode 100644 hw/mem/memory-device.c
>  create mode 100644 include/hw/mem/memory-device.h
>  rename stubs/{qmp_pc_dimm.c => qmp_memory_device.c} (61%)
> 
> -- 
> 2.14.3