Messages in this thread | | | Date | Mon, 27 Oct 2014 15:16:45 +0000 | From | David Vrabel <> | Subject | Re: [PATCH 0/2] xen: Switch to virtual mapped linear p2m list |
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On 27/10/14 14:52, Juergen Gross wrote: > Paravirtualized kernels running on Xen use a three level tree for > translation of guest specific physical addresses to machine global > addresses. This p2m tree is used for construction of page table > entries, so the p2m tree walk is performance critical. > > By using a linear virtual mapped p2m list accesses to p2m elements > can be sped up while even simplifying code. To achieve this goal > some p2m related initializations have to be performed later in the > boot process, as the final p2m list can be set up only after basic > memory management functions are available.
What impact does this have on 32-bit guests which don't have huge amount of virtual address space?
I think a 32-bit guest could have up to 64 GiB of PFNs, which would require a 128 MiB p2m array, which is too large?
David
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