On Fri, 20 Apr 2018 14:34:53 +0200
David Hildenbrand <da...@redhat.com> 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.
A couple of high level questions as relevant code is not here:
1. what would hotplug/unplug call chain look like in case of virtio-pmem
device
(reason I'm asking is that pmem being PCI device would trigger
PCI bus hotplug controller and then it somehow should piggyback
to Machine provided hotplug handlers, so I wonder what kind of
havoc it would cause on hotplug infrastructure)
2. why not use PCI bar mapping mechanism to do mapping since pmem is PCI
device?
> 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 (3):
> pc-dimm: factor out MemoryDevice interface
> machine: make MemoryHotplugState accessible via the machine
> pc-dimm: factor out address space logic into MemoryDevice code
>
> hw/i386/acpi-build.c | 3 +-
> hw/i386/pc.c | 24 ++-
> hw/mem/Makefile.objs | 1 +
> hw/mem/memory-device.c | 282 +++++++++++++++++++++++++
> hw/mem/pc-dimm.c | 304
> +++++++--------------------
> hw/ppc/spapr.c | 24 ++-
> hw/ppc/spapr_hcall.c | 1 +
> include/hw/boards.h | 16 ++
> include/hw/mem/memory-device.h | 48 +++++
> include/hw/mem/pc-dimm.h | 26 +--
> numa.c | 3 +-
> qmp.c | 4 +-
> stubs/Makefile.objs | 2 +-
> stubs/{qmp_pc_dimm.c => qmp_memory_device.c} | 4 +-
> 14 files changed, 465 insertions(+), 277 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%)
>
