[RFC 00/18] PAPR HPT resizing, guest side & host side preliminaries

[David Gibson]

This is an incomplete implementation of the kernel parts of the PAPR
hashed page table (HPT) resizing extension.

It contains a complete guest-side implementation - or as complete as
it can be until we have a final PAPR change.

It also contains preliminary patches towards a host side
implementation for KVM HV (the KVM PR and TCG host-side
implementations live in qemu).  This isn't working yet, but has an
outline of the approach.

I'm hoping particularly for comment on the locking / synchronization
between the resizing work thread and the hypercalls in patch 18/18.
This is much hairier than I'd like, in order to handle the various
failure / cancellation paths, but as yet I haven't seen a simpler way
of accomplishing what we need.

David Gibson (18):
  powerpc/mm: Clean up error handling for htab_remove_mapping
  powerpc/mm: Handle removing maybe-present bolted HPTEs
  powerpc/mm: Clean up memory hotplug failure paths
  powerpc/mm: Split hash page table sizing heuristic into a helper
  pseries: Add hypercall wrappers for hash page table resizing
  pseries: Add support for hash table resizing
  pseries: Advertise HPT resizing support via CAS
  pseries: Automatically resize HPT for memory hot add/remove
  powerpc/kvm: Corectly report KVM_CAP_PPC_ALLOC_HTAB
  powerpc/kvm: Add capability flag for hashed page table resizing
  powerpc/kvm: Rename kvm_alloc_hpt() for clarity
  powerpc/kvm: Gather HPT related variables into sub-structure
  powerpc/kvm: Don't store values derivable from HPT order
  powerpc/kvm: Split HPT allocation from activation
  powerpc/kvm: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size
  powerpc/kvm: HPT resizing stub implementation
  powerpc/kvm: Advertise availablity of HPT resizing on KVM HV
  powerpc/kvm: Outline of HPT resizing implementation

 arch/powerpc/include/asm/firmware.h       |   5 +-
 arch/powerpc/include/asm/hvcall.h         |   2 +
 arch/powerpc/include/asm/kvm_book3s.h     |   6 +
 arch/powerpc/include/asm/kvm_book3s_64.h  |  15 +
 arch/powerpc/include/asm/kvm_host.h       |  18 +-
 arch/powerpc/include/asm/kvm_ppc.h        |  11 +-
 arch/powerpc/include/asm/machdep.h        |   3 +-
 arch/powerpc/include/asm/mmu-hash64.h     |   3 +
 arch/powerpc/include/asm/plpar_wrappers.h |  12 +
 arch/powerpc/include/asm/prom.h           |   1 +
 arch/powerpc/include/asm/sparsemem.h      |   1 +
 arch/powerpc/kernel/prom_init.c           |   2 +-
 arch/powerpc/kvm/book3s_64_mmu_hv.c       | 452 ++++++++++++++++++++++++------
 arch/powerpc/kvm/book3s_hv.c              |  38 ++-
 arch/powerpc/kvm/book3s_hv_builtin.c      |   8 +-
 arch/powerpc/kvm/book3s_hv_rm_mmu.c       |  62 ++--
 arch/powerpc/kvm/powerpc.c                |  17 +-
 arch/powerpc/mm/hash_utils_64.c           | 128 +++++++--
 arch/powerpc/mm/init_64.c                 |  47 ++--
 arch/powerpc/mm/mem.c                     |  14 +-
 arch/powerpc/platforms/pseries/firmware.c |   1 +
 arch/powerpc/platforms/pseries/lpar.c     | 119 +++++++-
 include/uapi/linux/kvm.h                  |   1 +
 23 files changed, 774 insertions(+), 192 deletions(-)

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2.5.0