[PATCH 0/3] avoid unnecessary memslot rmap walks

[Anthony Yznaga <anthony.yznaga@oracle.com>]

While investigating optimizing qemu start time for large memory guests
I found that kvm_mmu_slot_apply_flags() is walking rmaps to update
existing sptes when creating or moving a slot but that there won't be
any existing sptes to update and any sptes inserted once the new memslot
is visible won't need updating.  I can't find any reason for this not to
be the case, but I've taken a more cautious approach to fixing this by
dividing things into three patches.

Anthony Yznaga (3):
  KVM: x86: remove unnecessary rmap walk of read-only memslots
  KVM: x86: avoid unnecessary rmap walks when creating/moving slots
  KVM: x86: minor code refactor and comments fixup around dirty logging

 arch/x86/kvm/x86.c | 106 +++++++++++++++++++++++++----------------------------
 1 file changed, 49 insertions(+), 57 deletions(-)

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2.13.3