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Re: [Xen-devel] Trouble using update_va_mapping

To: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] Trouble using update_va_mapping
From: Mathieu Ropert <mro@xxxxxxxxxx>
Date: Tue, 14 Feb 2006 14:28:14 +0100
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Keir Fraser wrote:

On 13 Feb 2006, at 16:06, Mathieu Ropert wrote:

i'm trying to run a very simple domU kernel on Xen/x86_64, and i'm getting some trouble with update_va_mapping(): when trying to remap some page table entry, i find the virtual address still pointing to the same machine address after the return of the hypercall.

What machine page does 'cons' point at before update_va_mapping()? Is it definitely a different page?

 -- Keir

Done some more checks and found the bug: the virtual address i used was mis-aligned (missing a 0x in .align directive :)). How does update_va_mapping() should normally behave when given a non paged-aligned virtual address? From the code, i guess it just remap the page containing the given address (discarding the lower 12 bits). Is this intended?


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