From mboxrd@z Thu Jan  1 00:00:00 1970
From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Subject: Re: [PATCH 4/9] KVM: define kvm_bad_pfn statically
Date: Fri, 03 Aug 2012 16:13:54 +0800
Message-ID: <501B8842.9040109@linux.vnet.ibm.com>
References: <5014F053.8020305@linux.vnet.ibm.com> <5014F0E1.4010909@linux.vnet.ibm.com> <20120802131527.GE25344@amt.cnet> <20120803000125.GB12559@bloggs.ozlabs.ibm.com>
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Cc: Marcelo Tosatti <mtosatti@redhat.com>, Avi Kivity <avi@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
To: Paul Mackerras <paulus@samba.org>
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In-Reply-To: <20120803000125.GB12559@bloggs.ozlabs.ibm.com>
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Marcelo, Paul,

Thanks for your review!

On 08/03/2012 08:01 AM, Paul Mackerras wrote:
> On Thu, Aug 02, 2012 at 10:15:27AM -0300, Marcelo Tosatti wrote:
> 
>> Remind me what is the guarantee that -Exxx does not clash with
>> a valid pfn number?
> 
> A pfn number is an address >> PAGE_SHIFT, so it will have the top 12
> (at least) bits clear, whereas -Exxx will have the top bit set.
> 

Yes.

As this way is hard to understand and it will break huge memory support
on PAE 32bit cpu, i have used a new way in the v2:

http://marc.info/?l=linux-kernel&m=134398012027025&w=2

Please review the new version.