From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexander Graf <agraf@suse.de>
Subject: Re: [PATCH V2] PPC: Fix race in mtmsr paravirt implementation
Date: Thu, 13 Oct 2011 12:11:33 +0200
Message-ID: <4E96B955.6090803@suse.de>
References: <1318499228-14372-1-git-send-email-bharat.bhushan@freescale.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: kvm-ppc@vger.kernel.org, bharatb.yadav@gmail.com,
	Bharat Bhushan <bharat.bhushan@freescale.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>
To: Bharat Bhushan <r65777@freescale.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from cantor2.suse.de ([195.135.220.15]:40906 "EHLO mx2.suse.de"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1752274Ab1JMKIg (ORCPT <rfc822;kvm@vger.kernel.org>);
	Thu, 13 Oct 2011 06:08:36 -0400
In-Reply-To: <1318499228-14372-1-git-send-email-bharat.bhushan@freescale.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On 10/13/2011 11:47 AM, Bharat Bhushan wrote:
> The current implementation of mtmsr and mtmsrd are racy in that it does:
>
>    * check (int_pending == 0)
>    --->  host sets int_pending = 1<---
>    * write shared page
>    * done
>
> while instead we should check for int_pending after the shared page is written.
>
> Signed-off-by: Bharat Bhushan<bharat.bhushan@freescale.com>

Thanks, applied to kvm-ppc-next.


Alex