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* [PATCH v2 00/15] KVM: Dynamically size memslot arrays
@ 2019-10-22  0:35 Sean Christopherson
  2019-10-22  0:35 ` [PATCH v2 01/15] KVM: Reinstall old memslots if arch preparation fails Sean Christopherson
                   ` (17 more replies)
  0 siblings, 18 replies; 37+ messages in thread
From: Sean Christopherson @ 2019-10-22  0:35 UTC (permalink / raw)
  To: James Hogan, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, Paolo Bonzini, Radim Krčmář,
	Marc Zyngier
  Cc: linux-arm-kernel, Wanpeng Li, kvm, David Hildenbrand,
	Joerg Roedel, Cornelia Huck, linux-mips, Sean Christopherson,
	linux-kernel, kvm-ppc, Vitaly Kuznetsov, kvmarm, Jim Mattson

The end goal of this series is to dynamically size the memslot array so
that KVM allocates memory based on the number of memslots in use, as
opposed to unconditionally allocating memory for the maximum number of
memslots.  On x86, each memslot consumes 88 bytes, and so with 2 address
spaces of 512 memslots, each VM consumes ~90k bytes for the memslots.
E.g. given a VM that uses a total of 30 memslots, dynamic sizing reduces
the memory footprint from 90k to ~2.6k bytes.

The changes required to support dynamic sizing are relatively small,
e.g. are essentially contained in patches 12/13 and 13/13.  Patches 1-11
clean up the memslot code, which has gotten quite crusy, especially
__kvm_set_memory_region().  The clean up is likely not strictly necessary
to switch to dynamic sizing, but I didn't have a remotely reasonable
level of confidence in the correctness of the dynamic sizing without first
doing the clean up.

Testing, especially non-x86 platforms, would be greatly appreciated.  The
non-x86 changes are for all intents and purposes untested, e.g. I compile
tested pieces of the code by copying them into x86, but that's it.  In
theory, the vast majority of the functional changes are arch agnostic, in
theory...

v2:
  - Split "Drop kvm_arch_create_memslot()" into three patches to move
    minor functional changes to standalone patches [Janosch].
  - Rebase to latest kvm/queue (f0574a1cea5b, "KVM: x86: fix ...")
  - Collect an Acked-by and a Reviewed-by

Sean Christopherson (15):
  KVM: Reinstall old memslots if arch preparation fails
  KVM: Don't free new memslot if allocation of said memslot fails
  KVM: PPC: Move memslot memory allocation into prepare_memory_region()
  KVM: x86: Allocate memslot resources during prepare_memory_region()
  KVM: Drop kvm_arch_create_memslot()
  KVM: Explicitly free allocated-but-unused dirty bitmap
  KVM: Refactor error handling for setting memory region
  KVM: Move setting of memslot into helper routine
  KVM: Move memslot deletion to helper function
  KVM: Simplify kvm_free_memslot() and all its descendents
  KVM: Clean up local variable usage in __kvm_set_memory_region()
  KVM: Provide common implementation for generic dirty log functions
  KVM: Ensure validity of memslot with respect to kvm_get_dirty_log()
  KVM: Terminate memslot walks via used_slots
  KVM: Dynamically size memslot array based on number of used slots

 arch/mips/include/asm/kvm_host.h      |   2 +-
 arch/mips/kvm/mips.c                  |  68 +---
 arch/powerpc/include/asm/kvm_ppc.h    |  14 +-
 arch/powerpc/kvm/book3s.c             |  22 +-
 arch/powerpc/kvm/book3s_hv.c          |  36 +-
 arch/powerpc/kvm/book3s_pr.c          |  20 +-
 arch/powerpc/kvm/booke.c              |  17 +-
 arch/powerpc/kvm/powerpc.c            |  13 +-
 arch/s390/include/asm/kvm_host.h      |   2 +-
 arch/s390/kvm/kvm-s390.c              |  21 +-
 arch/x86/include/asm/kvm_page_track.h |   3 +-
 arch/x86/kvm/page_track.c             |  15 +-
 arch/x86/kvm/x86.c                    | 100 ++---
 include/linux/kvm_host.h              |  48 +--
 virt/kvm/arm/arm.c                    |  47 +--
 virt/kvm/arm/mmu.c                    |  18 +-
 virt/kvm/kvm_main.c                   | 546 ++++++++++++++++----------
 17 files changed, 467 insertions(+), 525 deletions(-)

-- 
2.22.0

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^ permalink raw reply	[flat|nested] 37+ messages in thread

end of thread, other threads:[~2019-10-24 20:48 UTC | newest]

Thread overview: 37+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-22  0:35 [PATCH v2 00/15] KVM: Dynamically size memslot arrays Sean Christopherson
2019-10-22  0:35 ` [PATCH v2 01/15] KVM: Reinstall old memslots if arch preparation fails Sean Christopherson
2019-10-23  9:29   ` Christoffer Dall
2019-10-22  0:35 ` [PATCH v2 02/15] KVM: Don't free new memslot if allocation of said memslot fails Sean Christopherson
2019-10-23  9:29   ` Christoffer Dall
2019-10-22  0:35 ` [PATCH v2 03/15] KVM: PPC: Move memslot memory allocation into prepare_memory_region() Sean Christopherson
2019-10-24 11:55   ` kbuild test robot
2019-10-22  0:35 ` [PATCH v2 04/15] KVM: x86: Allocate memslot resources during prepare_memory_region() Sean Christopherson
2019-10-22  0:35 ` [PATCH v2 05/15] KVM: Drop kvm_arch_create_memslot() Sean Christopherson
2019-10-22  0:35 ` [PATCH v2 06/15] KVM: Explicitly free allocated-but-unused dirty bitmap Sean Christopherson
2019-10-22  0:35 ` [PATCH v2 07/15] KVM: Refactor error handling for setting memory region Sean Christopherson
2019-10-22  0:35 ` [PATCH v2 08/15] KVM: Move setting of memslot into helper routine Sean Christopherson
2019-10-22  0:35 ` [PATCH v2 09/15] KVM: Move memslot deletion to helper function Sean Christopherson
2019-10-23  9:29   ` Christoffer Dall
2019-10-22  0:35 ` [PATCH v2 10/15] KVM: Simplify kvm_free_memslot() and all its descendents Sean Christopherson
2019-10-22  0:35 ` [PATCH v2 11/15] KVM: Clean up local variable usage in __kvm_set_memory_region() Sean Christopherson
2019-10-22  0:35 ` [PATCH v2 12/15] KVM: Provide common implementation for generic dirty log functions Sean Christopherson
2019-10-23  9:29   ` Christoffer Dall
2019-10-24 10:28   ` kbuild test robot
2019-10-22  0:35 ` [PATCH v2 13/15] KVM: Ensure validity of memslot with respect to kvm_get_dirty_log() Sean Christopherson
2019-10-22  0:35 ` [PATCH v2 14/15] KVM: Terminate memslot walks via used_slots Sean Christopherson
2019-10-22 14:04   ` Paolo Bonzini
2019-10-22 15:28     ` Sean Christopherson
2019-10-22 15:30       ` Paolo Bonzini
2019-10-22 15:52         ` Sean Christopherson
2019-10-22 15:53           ` Paolo Bonzini
2019-10-24 19:38             ` Sean Christopherson
2019-10-24 19:42               ` Sean Christopherson
2019-10-24 20:24               ` Paolo Bonzini
2019-10-24 20:48                 ` Sean Christopherson
2019-10-22  0:35 ` [PATCH v2 15/15] KVM: Dynamically size memslot array based on number of used slots Sean Christopherson
2019-10-22 14:04   ` Paolo Bonzini
2019-10-22 15:22     ` Sean Christopherson
2019-10-22 13:59 ` [PATCH v2 00/15] KVM: Dynamically size memslot arrays Paolo Bonzini
2019-10-23 18:56   ` Christian Borntraeger
2019-10-22 14:04 ` Paolo Bonzini
2019-10-23  9:39 ` Christoffer Dall

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