From mboxrd@z Thu Jan  1 00:00:00 1970
From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Subject: Re: [PATCH v6 5/9] KVM: MMU: introduce SPTE_MMU_WRITEABLE bit
Date: Tue, 12 Jun 2012 10:23:47 +0800
Message-ID: <4FD6A833.6060206@linux.vnet.ibm.com>
References: <4FC470C7.5040700@linux.vnet.ibm.com> <4FC4716A.8030304@linux.vnet.ibm.com> <20120611233212.GA29573@amt.cnet>
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Cc: Avi Kivity <avi@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
	KVM <kvm@vger.kernel.org>
To: Marcelo Tosatti <mtosatti@redhat.com>
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On 06/12/2012 07:32 AM, Marcelo Tosatti wrote:

> On Tue, May 29, 2012 at 02:49:14PM +0800, Xiao Guangrong wrote:
>> This bit indicates whether the spte can be writable on MMU, that means
>> the corresponding gpte is writable and the corresponding gfn is not
>> protected by shadow page protection
> 
> Why is this still necessary, now that only sptes of direct shadow pages 
> are updated locklessly? 
> 


Yes, but it is still needed, for nested npt/ept, we need protect
the nested page tables.