[RFC PATCH 0/6] KVM: PPC: Book3S HV P9: Reduce guest entry/exit

Nicholas Piggin npiggin at gmail.com
Thu Jul 15 23:15:12 AEST 2021


This goes on top of the previous speedup series. The previous series is
mostly invovled with reducing the cost of SPR accesses. This one starts
to look beyond those, to atomics, barriers, and other logic that can be
reduced. After this series the P9 path uses very few things from the
vcore structure. This saves several hundred cycles for guest entry/exit
on a POWER9.

Thanks,
Nick

Nicholas Piggin (6):
  KVM: PPC: Book3S HV P9: Add unlikely annotation for !mmu_ready
  KVM: PPC: Book3S HV P9: Avoid cpu_in_guest atomics on entry and exit
  KVM: PPC: Book3S HV P9: Remove most of the vcore logic
  KVM: PPC: Book3S HV P9: Tidy kvmppc_create_dtl_entry
  KVM: PPC: Book3S HV P9: Stop using vc->dpdes
  KVM: PPC: Book3S HV P9: Remove subcore HMI handling

 arch/powerpc/include/asm/kvm_book3s_64.h |   1 -
 arch/powerpc/include/asm/kvm_host.h      |   1 -
 arch/powerpc/kvm/book3s_hv.c             | 250 +++++++++++++----------
 arch/powerpc/kvm/book3s_hv_builtin.c     |   2 +
 arch/powerpc/kvm/book3s_hv_hmi.c         |   7 +-
 arch/powerpc/kvm/book3s_hv_p9_entry.c    |  35 +++-
 arch/powerpc/kvm/book3s_hv_ras.c         |   4 +
 7 files changed, 185 insertions(+), 115 deletions(-)

-- 
2.23.0



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