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Re: [Xen-devel] Purpose of linear page tables

To: Jacob Gorm Hansen <jacobg@xxxxxxx>
Subject: Re: [Xen-devel] Purpose of linear page tables
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Sat, 2 Apr 2005 08:14:40 +0100
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On 2 Apr 2005, at 02:47, Jacob Gorm Hansen wrote:

now that Xen has writable page tables, I was wondering if there is any real need for the linear page tables in Xen? It seems some of the drivers still use them, but I imagine they could use the regular mmu_updates just as efficiently. Am I wrong?

We use update_va_mapping() on demand fault paths as well, where it avoids us having to map_domain_mem() the pte in Xen. This would be less of an advantage on x86_64 where we'll have a 1:1 mapping of all memory anyway: but in that case linear address space is not so scarce. :-)

 - Keir


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