From mboxrd@z Thu Jan  1 00:00:00 1970
From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Subject: Re: [PATCH v3 2/3] KVM: MMU: fix accessed bit set on prefault path
Date: Wed, 01 Dec 2010 00:52:22 +0800
Message-ID: <4CF52BC6.9020401@cn.fujitsu.com>
References: <4CF4C535.8080405@cn.fujitsu.com> <4CF4C587.7080000@cn.fujitsu.com> <20101130132915.GG2187@redhat.com>
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Cc: Avi Kivity <avi@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
To: Gleb Natapov <gleb@redhat.com>
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In-Reply-To: <20101130132915.GG2187@redhat.com>
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On 11/30/2010 09:29 PM, Gleb Natapov wrote:

>> +	if (!shadow_accessed_mask)
>> +		return;
>> +
> I don't get this. As far as I can see VMX inits shadow_accessed_mask to
> be zero if ept is enabled. This line here means that we never prefault with ept
> enabled. It is opposite from what it should be.
> 

Since it's no accessed bit on EPT, it's no way to distinguish between actually
accessed translations and prefault.