Re: [PATCH 5/6] kvm, x86: use ro page and don't copy shared page

[Avi Kivity]

On 07/18/2010 06:23 PM, Gleb Natapov wrote:
> On Sun, Jul 18, 2010 at 06:14:11PM +0300, Avi Kivity wrote:
>    
> > On 07/17/2010 07:31 AM, Gleb Natapov wrote:
> >      
> > > > > Currently pages allocated for guest memory are required to be RW, so after your series
> > > > > behaviour will remain exactly the same as before.
> > > > >            
> > > > Except KSM pages.
> > > >
> > > >          
> > > KSM page will be COWed by __get_user_pages_fast(addr, 1, 1, page) in
> > > get_user_page_and_protection() just like it COWed now, no?
> > >        
> > Well, we don't want to COW it on write faults.
> >      

I meant read faults here.

> > The optimal behaviour is:
> >
> > - write faults: COW and instantiate a writeable spte
> >      
> So do we or don't we want to COW on write faults?
>    

We do (no choice).

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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/