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SubjectRe: [PATCH 3/6] KVM: MMU: introduce gfn_to_page_atomic() and gfn_to_pfn_atomic()
On 06/16/2010 01:51 PM, huang ying wrote:
> On Tue, Jun 15, 2010 at 7:22 PM, Avi Kivity<avi@redhat.com> wrote:
>
>> btw, is_hwpoison_address() is racy. While it looks up the address, some
>> other task can unmap the page tables under us.
>>
>> Andi/Huang?
>>
>> One way of fixing it is get_user_pages_ptes_fast(), which also returns the
>> pte, also atomically. I want it for other reasons as well (respond to a
>> read fault by gupping the page for read, but allowing write access if the
>> pte indicates it is writeable).
>>
> Yes. is_hwpoison_address() is racy. But I think it is not absolutely
> necessary to call is_hwpoison_address() in hva_to_pfn_atomic(), is it?
>

We can probably ignore it, yes.

> For is_hwpoison_address() in hva_to_pfn(), we can protect it with mmap_sem.
>

Not very appealing, but should work.

--
error compiling committee.c: too many arguments to function



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