From mboxrd@z Thu Jan  1 00:00:00 1970
From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Subject: Re: [PATCH 2/7] KVM: MMU: cleanup for error mask set while walk guest
 page table
Date: Tue, 28 Sep 2010 16:58:00 +0800
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References: <4CA06BA4.4090303@cn.fujitsu.com> <4CA06BEF.7060401@cn.fujitsu.com> <4CA0AA7E.4090901@redhat.com>
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Cc: Marcelo Tosatti <mtosatti@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
To: Avi Kivity <avi@redhat.com>
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On 09/27/2010 10:30 PM, Avi Kivity wrote:

>>       r = FNAME(walk_addr)(&walker, vcpu, vaddr,
>> -                 !!(access&  PFERR_WRITE_MASK),
>> -                 !!(access&  PFERR_USER_MASK),
>> -                 !!(access&  PFERR_FETCH_MASK));
>> +                 access&  PFERR_WRITE_MASK,
>> +                 access&  PFERR_USER_MASK,
>> +                 access&  PFERR_FETCH_MASK);
>>
>>       if (r) {
>>           gpa = gfn_to_gpa(walker.gfn);
> 
> Interesting.  Maybe a next step is to pass the page-fault error code
> instead of the various bits? 

Yeah, it's a good idea, i'll post a patch to do it.

> Not sure how that interacts with nested
> ept (which has a different permission model).
> 

Umm, we just move the error code parsing from the caller site to FNAME(walk_addr)
function, i think it not make trouble for implement nested ept.