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Re: [Xen-devel] [PATCH] x86-64 linux: another adjustment to vmalloc fault handling

On 17 Feb 2006, at 10:38, Jan Beulich wrote:

Changeset 8847 improved things, but doesn't generally work. We namely experienced problems (when we originally tried the same change) with accesses to machine_to_phys_mapping, which (in mfn_to_pfn) is specifically allowed to fault. Hence there should not be attempts to fix up faults within the hypervisor range (as for any page table entries obtained there no m2p translation exists for the guest, resulting in bogus physical addresses getting used for further fault
processing, frequently leading to nested faults).

But machine_to_phys_mapping == 0xffff800000000000 while
PAGE_OFFSET == HYPERVISOR_VIRT_END == 0xffff880000000000.

So the patch doesn't really change anything, and machine_to_phys_mapping lives below both PAGE_OFFSET and HYPERVISOR_VIRT_END anyway.

 -- Keir

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