From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCHv2 3/4] Add HYPER-V apic access MSRs.
Date: Sun, 17 Jan 2010 07:32:32 -0500
Message-ID: <20100117123232.GA10114@infradead.org>
References: <1263719028-24765-1-git-send-email-gleb@redhat.com> <1263719028-24765-4-git-send-email-gleb@redhat.com> <4B530090.50506@redhat.com>
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Cc: Gleb Natapov <gleb@redhat.com>, mtosatti@redhat.com,
	kvm@vger.kernel.org
To: Avi Kivity <avi@redhat.com>
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On Sun, Jan 17, 2010 at 02:20:32PM +0200, Avi Kivity wrote:
>> +		addr = kmap_atomic(page, KM_USER0);
>> +		clear_user_page(addr, vaddr, page);
>> +		kunmap_atomic(addr, KM_USER0);
>>    
>
> Surprising that clear_user_page needs kmap_atomic() (but true).

There's a clear_user_highpage helper to take care of it for you.