Re: [RFC] respect the referenced bit of KVM guest pages?

[Avi Kivity <avi@redhat.com>]

On 08/05/2009 06:15 PM, Rik van Riel wrote:
> Avi Kivity wrote:
>
>>> If so, we could unmap them when they get moved from the
>>> active to the inactive list, and soft fault them back in
>>> on access, emulating the referenced bit for EPT pages and
>>> making page replacement on them work like it should.
>>
>> It should be easy to implement via the mmu notifier callback: when 
>> the mm calls clear_flush_young(), mark it as young, and unmap it from 
>> the EPT pagetable.
>
> You mean "mark it as old"?

I meant 'return young, and drop it from the EPT pagetable'.

If we use the present bit as a replacement for the accessed bit, present 
means young, and clear_flush_young means "if present, return young and 
unmap, otherwise return old'.

See kvm_age_rmapp() in arch/x86/kvm/mmu.c.

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