We can interrupt the vcpu only when it's running in guest mode to reduce IPI. It looks like only ia64 and x86 need to send IPI to other vcpus, so i only add the implementation of 'vcpu->guest_mode' in ia64, but i don't know ia64 well, please point out the right way for me if the implementation is incorrect And ia64 is not tested since i don't have ia64 box Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxx> --- arch/ia64/kvm/kvm-ia64.c | 2 ++ virt/kvm/kvm_main.c | 3 ++- 2 files changed, 4 insertions(+), 1 deletions(-) diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index 70d224d..15c11b2 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -662,6 +662,7 @@ again: goto vcpu_run_fail; srcu_read_unlock(&vcpu->kvm->srcu, idx); + atomic_set(&vcpu->guest_mode, 1); kvm_guest_enter(); /* @@ -683,6 +684,7 @@ again: */ barrier(); kvm_guest_exit(); + atomic_set(&vcpu->guest_mode, 0); preempt_enable(); idx = srcu_read_lock(&vcpu->kvm->srcu); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b1b6cbb..6648c6e 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -153,7 +153,8 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req) if (kvm_make_check_request(req, vcpu)) continue; cpu = vcpu->cpu; - if (cpus != NULL && cpu != -1 && cpu != me) + if (cpus != NULL && cpu != -1 && cpu != me && + atomic_read(&vcpu->guest_mode)) cpumask_set_cpu(cpu, cpus); } if (unlikely(cpus == NULL)) -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
