Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Wanpeng Li <kernellwp@gmail.com>
To:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@redhat.com>
Subject: [PATCH v4 0/3] KVM: Yield to IPI target if necessary
Date:   Tue, 11 Jun 2019 20:23:47 +0800
Message-Id: <1560255830-8656-1-git-send-email-wanpengli@tencent.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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 
increasement 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).

v3 -> v4: 
 * check map->phys_map[dest_id]
 * more cleaner kvm_sched_yield()

v2 -> v3:
 * add bounds-check on dest_id

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: Yield to IPI target if necessary
  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                       | 21 +++++++++++++++++++++
 include/uapi/linux/kvm_para.h            |  1 +
 7 files changed, 61 insertions(+), 1 deletion(-)

-- 
2.7.4