tree 4e625e806cfb7c30e8053a7e88ad04f4aa83b7a4
parent f07f21b3e20c11017cea17ec841f0150a62aac53
author Martin Schwidefsky <schwidefsky@de.ibm.com> 1447155028 +0100
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1447671858 +0100

s390: avoid cache aliasing under z/VM and KVM

commit 1f6b83e5e4d3 ("s390: avoid z13 cache aliasing") checks for the
machine type to optimize address space randomization and zero page
allocation to avoid cache aliases.

This check might fail under a hypervisor with migration support.
z/VMs "Single System Image and Live Guest Relocation" facility will
"fake" the machine type of the oldest system in the group. For example
in a group of zEC12 and Z13 the guest appears to run on a zEC12
(architecture fencing within the relocation domain)

Remove the machine type detection and always use cache aliasing
rules that are known to work for all machines. These are the z13
aliasing rules.

Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>