2015-02-27 14:57:10

by David Vrabel

[permalink] [raw]
Subject: Re: [PATCH] xen: correct bug in p2m list initialization

On 27/02/15 14:45, Juergen Gross wrote:
> Commit 054954eb051f35e74b75a566a96fe756015352c8 ("xen: switch to
> linear virtual mapped sparse p2m list") introduced an error.
>
> During initialization of the p2m list a p2m identity area mapped by
> a complete identity pmd entry has to be split up into smaller chunks
> sometimes, if a non-identity pfn is introduced in this area.
>
> If this non-identity pfn is not at index 0 of a p2m page the new
> p2m page needed is initialized with wrong identity entries, as the
> identity pfns don't start with the value corresponding to index 0,
> but with the initial non-identity pfn. This results in weird wrong
> mappings.
>
> Correct the wrong initialization by starting with the correct pfn.

Applied to stable/for-linus-4.0, thanks.

David