Avi Kivity wrote:
>>
>
> We've considered this in the past, it makes sense. The big question is
> whether any guests actually map the same page table through PDEs with
> different permissions (mapping the same page table through multiple PDEs
> is very common, but always with the same permissions). Do you know of
> any such guest?
I also don't know whether have such guest.
Maybe my idea is no good for current OS, thanks for your comments.
Xiao
On 04/01/2010 12:05 PM, Xiao Guangrong wrote:
>
>> We've considered this in the past, it makes sense. The big question is
>> whether any guests actually map the same page table through PDEs with
>> different permissions (mapping the same page table through multiple PDEs
>> is very common, but always with the same permissions). Do you know of
>> any such guest?
>>
> I also don't know whether have such guest.
> Maybe my idea is no good for current OS, thanks for your comments.
>
In fact there are plans to make kvm such a guest (when running in nested
mode) - when we perform live migration we write-protect all guest pages,
and it's reasonable to use the top-level shadow page to write protect
all memory at once instead of iterating over all mmu pages. When that
goes in, we should also implement your idea.
--
error compiling committee.c: too many arguments to function