[PATCH 0/2] KVM: X86: Add dedicated pCPU hint and per-VM non-HLT-exiting capability

From: Wanpeng Li
Date: Fri Feb 02 2018 - 02:12:26 EST


Waiman Long mentioned that:

Generally speaking, unfair lock performs well for VMs with a small
number of vCPUs. Native qspinlock may perform better than pvqspinlock
if there is vCPU pinning and there is no vCPU over-commitment.

This patchset adds a PV_DEDICATED performance hint to allow hypervisor
admin to choose the qspinlock to be used when a dedicated pCPU is
available.

In addition, according to the original hlt in VMX non-root mode discussion,
https://www.spinics.net/lists/kvm/msg152397.html This patchset also
adds the per-VM non-HLT-exiting capability to further improve performance
under the dedicated pCPU scenarios.

Wanpeng Li (2):
KVM: X86: Add dedicated pCPU hint PV_DEDICATED
KVM: X86: Add per-VM no-HLT-exiting capability

Documentation/virtual/kvm/api.txt | 11 +++++++++++
Documentation/virtual/kvm/cpuid.txt | 6 ++++++
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/include/uapi/asm/kvm_para.h | 1 +
arch/x86/kernel/kvm.c | 6 ++++++
arch/x86/kvm/vmx.c | 21 +++++++++++++++++++++
arch/x86/kvm/x86.c | 5 +++++
arch/x86/kvm/x86.h | 5 +++++
include/uapi/linux/kvm.h | 1 +
9 files changed, 58 insertions(+)

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2.7.4