Messages in this thread | | | Date | Tue, 17 May 2011 18:51:58 +0100 | From | Stefano Stabellini <> | Subject | Re: Xen MMU's requirement to pin pages RO and initial_memory_mapping. |
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CC'ing Keir in case he knows something I am missing.
On Mon, 16 May 2011, H. Peter Anvin wrote: > 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?
Unfortunately not that I am aware.
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