Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755122Ab0KAI7Y (ORCPT ); Mon, 1 Nov 2010 04:59:24 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:58345 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754862Ab0KAI7V (ORCPT ); Mon, 1 Nov 2010 04:59:21 -0400 Message-ID: <4CCE8270.5020300@cn.fujitsu.com> Date: Mon, 01 Nov 2010 17:03:44 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.11) Gecko/20100713 Thunderbird/3.0.6 MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , Gleb Natapov , LKML , KVM Subject: [RFC PATCH v2 6/7] KVM: fix the race while wakeup all pv guest References: <4CCE8143.3090105@cn.fujitsu.com> In-Reply-To: <4CCE8143.3090105@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1355 Lines: 43 In kvm_async_pf_wakeup_all(), we add a dummy apf to vcpu->async_pf.done without holding vcpu->async_pf.lock, it will break if we are handling apfs at this time. Also use 'list_empty_careful()' instead of 'list_empty()' Signed-off-by: Xiao Guangrong --- virt/kvm/async_pf.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c index d57ec92..6ef3373 100644 --- a/virt/kvm/async_pf.c +++ b/virt/kvm/async_pf.c @@ -200,7 +200,7 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu) { struct kvm_async_pf *work; - if (!list_empty(&vcpu->async_pf.done)) + if (!list_empty_careful(&vcpu->async_pf.done)) return 0; work = kmem_cache_zalloc(async_pf_cache, GFP_ATOMIC); @@ -211,7 +211,10 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu) get_page(bad_page); INIT_LIST_HEAD(&work->queue); /* for list_del to work */ + spin_lock(&vcpu->async_pf.lock); list_add_tail(&work->link, &vcpu->async_pf.done); + spin_unlock(&vcpu->async_pf.lock); + vcpu->async_pf.queued++; return 0; } -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/