Re: [PATCH 3/6] KVM: MMU: introduce gfn_to_page_atomic() and gfn_to_pfn_atomic()

[Avi Kivity]

On 06/16/2010 01:51 PM, huang ying wrote:
> On Tue, Jun 15, 2010 at 7:22 PM, Avi Kivity<avi@xxxxxxxxxx>  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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