From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: [PATCH v2 4/7] KVM: avoid unnecessary wait for a async pf Date: Mon, 01 Nov 2010 17:01:28 +0800 Message-ID: <4CCE81E8.6020001@cn.fujitsu.com> References: <4CCE8143.3090105@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , Gleb Natapov , LKML , KVM To: Avi Kivity Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:64858 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752300Ab0KAI5G (ORCPT ); Mon, 1 Nov 2010 04:57:06 -0400 In-Reply-To: <4CCE8143.3090105@cn.fujitsu.com> Sender: kvm-owner@vger.kernel.org List-ID: In current code, it checks async pf completion out of the wait context, like this: if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE && !vcpu->arch.apf.halted) r = vcpu_enter_guest(vcpu); else { ...... kvm_vcpu_block(vcpu) ^- waiting until 'async_pf.done' is not empty } kvm_check_async_pf_completion(vcpu) ^- delete list from async_pf.done So, if we check aysnc pf completion first, it can be blocked at kvm_vcpu_block Fixed by mark the vcpu is unhalted in kvm_check_async_pf_completion() path Signed-off-by: Xiao Guangrong --- arch/x86/kvm/x86.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 9b543f4..4da8485 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6280,6 +6280,7 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu, vcpu->arch.fault.address = work->arch.token; kvm_inject_page_fault(vcpu); } + vcpu->arch.apf.halted = false; } bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu) -- 1.7.0.4