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Re: [Xen-devel] grant table interface addition?

To: "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] grant table interface addition?
From: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Date: Fri, 31 Oct 2008 16:13:16 +0000
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>>> Keir Fraser <keir.fraser@xxxxxxxxxxxxx> 31.10.08 17:03 >>>
>On 31/10/08 15:52, "Jan Beulich" <jbeulich@xxxxxxxxxx> wrote:
>
>> Looking at that code I see some other potential issue, though:
>> GRANT_PTE_FLAGS include PAGE_USER for x86-64, but the generated
>> pte is passed through adjust_guest_l1e(), so without
>> GNTMAP_application_map we'd get global kernel mappings. Am I wrong
>> here?
>
>GRANT_PTE_FLAGS should include _PAGE_GUEST_KERNEL then?

No, it should uniformly include neither _PAGE_USER nor _PAGE_GUEST_KERNEL.
_PAGE_USER gets set when GNTMAP_application_map is specified, and
based on this setting of _PAGE_USER, adjust_guest_l1e() will set either
_PAGE_GUEST_KERNEL or _PAGE_GLOBAL.

Jan


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