Re: [Xen-devel] Live migration with MMIO pages

To:	Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>
Subject:	Re: [Xen-devel] Live migration with MMIO pages
From:	Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date:	Wed, 31 Oct 2007 18:23:35 +0000
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On 31/10/07 17:31, "Tim Deegan" <Tim.Deegan@xxxxxxxxxxxxx> wrote:

> For HVM guests we let that pass if the GFN is known to be acceptable
> MMIO (by its p2m type).  There needs to be an equivalent get-out here
> for PV guests -- iomem_access_permitted(d, mfn_x(gmfn), mfn_x(gmfn))
> should do.

We shouldn't really need to do a iomem_access_permitted() check here. If
this is a PV guest then the access check was made when the guest pagetable
was validated. We can just circumvent these checks entirely for PV guests.

 -- Keir

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