Re: [PATCH 4/4] Enabling Access bit when doing memory swapping

[Avi Kivity]

On 05/21/2012 01:35 PM, Hao, Xudong wrote:
> > 
> > That doesn't answer the question.  An atomic operation is now non-atomic.
> > 
> > You can calculate shadow_accessed_bit and keep on using clear_bit(), or
> > switch to cmpxchg64(), but don't just drop the dirty bit here.
> > 
>
> I know your meaning. How about this changes:
>
> ...
>             young = 1;
> +            if (enable_ept_ad_bits)
> +                clear_bit(ffs(shadow_accessed_mask), (unsigned long *)spte);

ffs() returns an off-by-one result, so this needs to be adjusted.  IIRC
bsfl is slow, but this shouldn't be a problem here.


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

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