Messages in this thread | | | Date | Tue, 17 May 2011 14:17:16 -0400 | From | Konrad Rzeszutek Wilk <> | Subject | Re: Xen MMU's requirement to pin pages RO and initial_memory_mapping. |
| |
> > xen_alloc_pte_init and xen_alloc_pmd_init are the ones that mark the > > pagetable pages RO and pin them, calling make_lowmem_page_readonly and > > pin_pagetable_pfn. > > > > alloc_pte/pmd are called right before hooking them into the pagetable; > > unfortunately that means that they fail at marking the pagetable pages > > RO: make_lowmem_page_readonly uses lookup_address to find the pte > > corresponding to a page, however at this point the pagetable pages are > > not mapped yet (usually they are not hooked but when they are hooked, the > > upper level pagetable page is not hooked), so lookup_address fails. > > Right. We don't have to walk the hooked pagetable, I think. We are passed > in the PMD/PGD of the PFN and we could look at the content of that PFN.
err, got that backwards. "passed in the PFN of the PMD/PGD".
| |