From patchwork Wed Jul 10 06:02:19 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiejun Chen X-Patchwork-Id: 257974 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 8ACAE2C0296 for ; Wed, 10 Jul 2013 16:01:37 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750894Ab3GJGBg (ORCPT ); Wed, 10 Jul 2013 02:01:36 -0400 Received: from mail1.windriver.com ([147.11.146.13]:37310 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750696Ab3GJGBf (ORCPT ); Wed, 10 Jul 2013 02:01:35 -0400 Received: from ALA-HCA.corp.ad.wrs.com (ala-hca.corp.ad.wrs.com [147.11.189.40]) by mail1.windriver.com (8.14.5/8.14.3) with ESMTP id r6A61WHX013872 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Tue, 9 Jul 2013 23:01:32 -0700 (PDT) Received: from Linux.corp.ad.wrs.com (128.224.162.214) by ALA-HCA.corp.ad.wrs.com (147.11.189.50) with Microsoft SMTP Server id 14.2.342.3; Tue, 9 Jul 2013 23:01:31 -0700 From: Tiejun Chen To: CC: , Subject: [v1][PATCH 1/1] KVM: PPC: disable preemption when using hard_irq_disable() Date: Wed, 10 Jul 2013 14:02:19 +0800 Message-ID: <1373436139-27998-1-git-send-email-tiejun.chen@windriver.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org We should ensure the preemption cannot occur while calling get_paca() insdide hard_irq_disable(), otherwise the paca_struct may be the wrong one just after. And btw, we may update timing stats in this case. Signed-off-by: Tiejun Chen --- arch/powerpc/kvm/booke.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index dcc94f0..9dae25d 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -839,6 +839,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, WARN_ON(local_paca->irq_happened != 0); #endif + preempt_disable(); /* * We enter with interrupts disabled in hardware, but * we need to call hard_irq_disable anyway to ensure that @@ -848,6 +849,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, /* update before a new last_exit_type is rewritten */ kvmppc_update_timing_stats(vcpu); + preempt_enable(); /* restart interrupts if they were meant for the host */ kvmppc_restart_interrupt(vcpu, exit_nr);