Re: [PATCH v2] xen: support 52 bit physical addresses in pv guests

From: Boris Ostrovsky
Date: Fri Oct 27 2017 - 18:34:15 EST




On 10/27/2017 01:49 PM, Juergen Gross wrote:
Physical addresses on processors supporting 5 level paging can be up to
52 bits wide. For a Xen pv guest running on such a machine those
physical addresses have to be supported in order to be able to use any
memory on the machine even if the guest itself does not support 5 level
paging.

So when reading/writing a MFN from/to a pte don't use the kernel's
PTE_PFN_MASK but a new XEN_PTE_MFN_MASK allowing full 40 bit wide MFNs.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>