Messages in this thread | | | Date | Mon, 16 May 2011 14:54:39 -0700 | From | "H. Peter Anvin" <> | Subject | Re: Xen MMU's requirement to pin pages RO and initial_memory_mapping. |
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On 05/16/2011 08:41 AM, Konrad Rzeszutek Wilk wrote: >> They become pagetable pages when: >> >> - they are explicitly pinned by pin_pagetable_pfn >> >> - they are hooked into the current pagetable > > Ok, so could we use those two calls to trigger the pagetable walk > and mark them RO as appropiate? Which call sites are those? The > xen_set_pgd/xen_set_pud/xen_set_pmd ? Presumarily we don't have > to do that for the PTE's that are already mapped (as > xen_setup_kernel_pagetable, and xen_map_identity_early do this > already). > >> Like you wrote, considering that the x86_64 version of >> kernel_physical_mapping_init hooks the pagetable pages into the >> currently used pagetable, it wouldn't be possible to mark the pagetable >> pages RO after init_memory_mapping. >
Doesn't Xen have some kind of compatibility mode which could be used during setup?
-hpa
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