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RE: [Xen-devel] Vitrual TLBs



No Anthony, I didn't refer to shadow paging. I meant virtual TLB's only.
I know that shadow tables are maintained in XEN.

-----Original Message-----
From: Anthony Liguori [mailto:aliguori@xxxxxxxxxx] 
Sent: Tuesday, November 21, 2006 1:31 AM
To: Liang Yang
Cc: Sameer Ahuja; Tim Deegan; sameer.ahuja81@xxxxxxxxx;
xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-devel] Vitrual TLBs

Liang Yang wrote:
> AMD will provide support for nested paging that caches address 
> translations
> to reduce memory accesses in its latest quad-core CPUs. As the
hypervisor
> can get pretty bogged down managing all of this and the processor is
> constantly switching from guest OS mode to hypervisor mode and back, 
> Nesting
> page tables and caching memory addresses are ways of freeing things up

> as it
> cuts down on memory access time.
>
> So Xen may not need such kind of virtual TLB anymore.

If by virtual TLB you are actually referring to shadow paging (and I 
would argue that they are very different concepts), then sorry, I 
misunderstood the initial question.

Yes, Xen supports shadow paging.  Both Intel and AMD are planning on 
supporting hardware shadow paging too in future processors.  I think it 
remains to be see if the hardware shadow paging is flexible enough to 
totally replace software shadow paging.

Regards,

Anthony Liguori

> Liang
>
> ----- Original Message -----
> From: "Anthony Liguori" <aliguori@xxxxxxxxxx>
> To: "Sameer Ahuja" <sameer.ahuja@xxxxxxxxxxx>
> Cc: "Tim Deegan" <Tim.Deegan@xxxxxxxxxxxxx>;
<sameer.ahuja81@xxxxxxxxx>;
> <xen-devel@xxxxxxxxxxxxxxxxxxx>
> Sent: Monday, November 20, 2006 9:53 AM
> Subject: Re: [Xen-devel] Vitrual TLBs
>
>
>> Sameer Ahuja wrote:
>>> Hi,
>>>
>>> Does XEN have the concept of virtual TLBs?
>>>
>>
>> Not really.
>>
>> Regards,
>>
>> Anthony Liguori
>>
>>> Regards,
>>> Sameer
>>>
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>>> http://lists.xensource.com/xen-devel
>>>
>>>
>>
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-devel
>>
>
>
> _______________________________________________
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