[PATCH RESEND v2 0/3] KVM: Yield to IPI target if necessary

From: Wanpeng Li
Date: Tue May 28 2019 - 03:59:59 EST


The idea is from Xen, when sending a call-function IPI-many to vCPUs,
yield if any of the IPI target vCPUs was preempted. 17% performance
increase of ebizzy benchmark can be observed in an over-subscribe
environment. (w/ kvm-pv-tlb disabled, testing TLB flush call-function
IPI-many since call-function is not easy to be trigged by userspace
workload).

v1 -> v2:
* check map is not NULL
* check map->phys_map[dest_id] is not NULL
* make kvm_sched_yield static
* change dest_id to unsinged long

Wanpeng Li (3):
KVM: X86: Implement PV sched yield in linux guest
KVM: X86: Implement PV sched yield hypercall
KVM: X86: Expose PV_SCHED_YIELD CPUID feature bit to guest

Documentation/virtual/kvm/cpuid.txt | 4 ++++
Documentation/virtual/kvm/hypercalls.txt | 11 +++++++++++
arch/x86/include/uapi/asm/kvm_para.h | 1 +
arch/x86/kernel/kvm.c | 21 +++++++++++++++++++++
arch/x86/kvm/cpuid.c | 3 ++-
arch/x86/kvm/x86.c | 26 ++++++++++++++++++++++++++
include/uapi/linux/kvm_para.h | 1 +
7 files changed, 66 insertions(+), 1 deletion(-)

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2.7.4