[PATCH v4 0/2] arm/arm64: KVM: Optimize arm64 fp/simd, saves 30-50% on exits for non-VHE

Mario Smarduch m.smarduch at samsung.com
Fri Jul 10 18:19:05 PDT 2015

This is a followp to previous iteration but implemented on top of VHE patches. 
Only non-VHE path is addressied by this patch. In second patch 32-bit handler 
is updated to keep exit handling consistent with 64-bit code, and nothing
has changed.

Currently we save/restore fp/simd on each exit, the first  patch optimizes 
arm64 save/restore, we only do so on Guest access. hackbench and
several lmbench tests show anywhere from 30% to 50% of exits don't 
save/restore fp/simd register set.

Tested on Foundation Model, unfortuntely not tested yet on VHE enabled model.

Mario Smarduch (2):
  Optimize arm64 non-VHE fpsimd skip 30-50% save/restore on exits
  keep arm vfp/simd exit handling consistent with arm64

 arch/arm/kvm/interrupts.S        | 14 +++++-----
 arch/arm64/include/asm/kvm_arm.h |  5 +++-
 arch/arm64/kvm/hyp.S             | 58 +++++++++++++++++++++++++++++++++++++---
 3 files changed, 66 insertions(+), 11 deletions(-)


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