From mboxrd@z Thu Jan  1 00:00:00 1970
From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Subject: Re: [PATCH v3 03/13] nEPT: Add EPT tables support to paging_tmpl.h
Date: Wed, 22 May 2013 09:10:45 +0800
Message-ID: <519C1B15.5030706@linux.vnet.ibm.com>
References: <1368939152-11406-1-git-send-email-jun.nakajima@intel.com> <1368939152-11406-3-git-send-email-jun.nakajima@intel.com> <519B27AC.6090903@linux.vnet.ibm.com>	<519B3095.5020209@linux.vnet.ibm.com> <20130521090102.GA4725@redhat.com>	<519B54EF.80906@linux.vnet.ibm.com> <CAL54oT3KH3=Hw_Q69GhtWhiZ+MBrUnBUt_ncC3MGd-hR45-OhQ@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Cc: Gleb Natapov <gleb@redhat.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Paolo Bonzini <pbonzini@redhat.com>
To: "Nakajima, Jun" <jun.nakajima@intel.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from e28smtp05.in.ibm.com ([122.248.162.5]:35954 "EHLO
	e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753519Ab3EVBKx (ORCPT <rfc822;kvm@vger.kernel.org>);
	Tue, 21 May 2013 21:10:53 -0400
Received: from /spool/local
	by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted
	for <kvm@vger.kernel.org> from <xiaoguangrong@linux.vnet.ibm.com>;
	Wed, 22 May 2013 06:36:37 +0530
Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62])
	by d28dlp02.in.ibm.com (Postfix) with ESMTP id C561A394002D
	for <kvm@vger.kernel.org>; Wed, 22 May 2013 06:40:49 +0530 (IST)
Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63])
	by d28relay05.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r4M1Ah5T6226310
	for <kvm@vger.kernel.org>; Wed, 22 May 2013 06:40:43 +0530
Received: from d28av01.in.ibm.com (loopback [127.0.0.1])
	by d28av01.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r4M1Alac020668
	for <kvm@vger.kernel.org>; Wed, 22 May 2013 01:10:48 GMT
In-Reply-To: <CAL54oT3KH3=Hw_Q69GhtWhiZ+MBrUnBUt_ncC3MGd-hR45-OhQ@mail.gmail.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On 05/22/2013 06:26 AM, Nakajima, Jun wrote:
> On Tue, May 21, 2013 at 4:05 AM, Xiao Guangrong
> <xiaoguangrong@linux.vnet.ibm.com> wrote:
>> On 05/21/2013 05:01 PM, Gleb Natapov wrote:
>>> On Tue, May 21, 2013 at 04:30:13PM +0800, Xiao Guangrong wrote:
>>>>>> @@ -772,6 +810,7 @@ static gpa_t FNAME(gva_to_gpa_nested)(struct kvm_vcpu *vcpu, gva_t vaddr,
>>>>>>
>>>>>>    return gpa;
>>>>>>  }
>>>>>> +#endif
>>>>>
>>>>> Strange!
>>>>>
>>>>> Why does nested ept not need these functions? How to emulate the instruction faulted on L2?
>>>>
>>>> Sorry, i misunderstood it. Have found the reason out.
>>>>
>>> You can write it down here for future reviewers :)
>>
>> Okay.
>>
>> The functions used to translate L2's gva to L1's gpa are paging32_gva_to_gpa_nested
>> and paging64_gva_to_gpa_nested which are created by PTTYPE == 32 and PTTYPE == 64.
>>
>>
> 
> Back to your comments on PT_MAX_FULL_LEVELS:
>> +     #ifdef CONFIG_X86_64
>> +     #define PT_MAX_FULL_LEVELS 4
>> +     #define CMPXCHG cmpxchg
>> +     #else
>> +     #define CMPXCHG cmpxchg64
>> +    #define PT_MAX_FULL_LEVELS 2
> I don't think we need to support nEPT on 32-bit hosts.  So, I plan to
> remove such code. What do you think?

Good to me. :)